A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2 | Last   [Sort by number of followers]   [Restore default list]

  Subjects -> ELECTRONICS (Total: 207 journals)
Showing 1 - 200 of 277 Journals sorted alphabetically
Acta Electronica Malaysia     Open Access  
Advanced Materials Technologies     Hybrid Journal   (Followers: 1)
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 8)
Advances in Electrical and Electronic Engineering     Open Access   (Followers: 9)
Advances in Electronics     Open Access   (Followers: 100)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Microelectronic Engineering     Open Access   (Followers: 13)
Advances in Power Electronics     Open Access   (Followers: 41)
Advancing Microelectronics     Hybrid Journal  
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 28)
Annals of Telecommunications     Hybrid Journal   (Followers: 8)
APSIPA Transactions on Signal and Information Processing     Open Access   (Followers: 8)
Archives of Electrical Engineering     Open Access   (Followers: 16)
Australian Journal of Electrical and Electronics Engineering     Hybrid Journal  
Batteries     Open Access   (Followers: 9)
Batteries & Supercaps     Hybrid Journal   (Followers: 5)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 31)
Bioelectronics in Medicine     Hybrid Journal  
Biomedical Instrumentation & Technology     Hybrid Journal   (Followers: 6)
BULLETIN of National Technical University of Ukraine. Series RADIOTECHNIQUE. RADIOAPPARATUS BUILDING     Open Access   (Followers: 2)
Bulletin of the Polish Academy of Sciences : Technical Sciences     Open Access   (Followers: 1)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 47)
China Communications     Full-text available via subscription   (Followers: 9)
Chinese Journal of Electronics     Hybrid Journal  
Circuits and Systems     Open Access   (Followers: 15)
Consumer Electronics Times     Open Access   (Followers: 5)
Control Systems     Hybrid Journal   (Followers: 308)
ECTI Transactions on Computer and Information Technology (ECTI-CIT)     Open Access  
ECTI Transactions on Electrical Engineering, Electronics, and Communications     Open Access   (Followers: 2)
Edu Elektrika Journal     Open Access   (Followers: 1)
Electrica     Open Access  
Electronic Design     Partially Free   (Followers: 124)
Electronic Markets     Hybrid Journal   (Followers: 7)
Electronic Materials Letters     Hybrid Journal   (Followers: 4)
Electronics     Open Access   (Followers: 109)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 10)
Electronics For You     Partially Free   (Followers: 103)
Electronics Letters     Hybrid Journal   (Followers: 26)
Elektronika ir Elektortechnika     Open Access   (Followers: 2)
Elkha : Jurnal Teknik Elektro     Open Access  
Emitor : Jurnal Teknik Elektro     Open Access   (Followers: 3)
Energy Harvesting and Systems     Hybrid Journal   (Followers: 4)
Energy Storage     Hybrid Journal   (Followers: 1)
Energy Storage Materials     Full-text available via subscription   (Followers: 4)
EPE Journal : European Power Electronics and Drives     Hybrid Journal  
EPJ Quantum Technology     Open Access   (Followers: 1)
EURASIP Journal on Embedded Systems     Open Access   (Followers: 11)
Facta Universitatis, Series : Electronics and Energetics     Open Access  
Foundations and Trends® in Communications and Information Theory     Full-text available via subscription   (Followers: 6)
Foundations and Trends® in Signal Processing     Full-text available via subscription   (Followers: 9)
Frequenz     Hybrid Journal   (Followers: 1)
Frontiers of Optoelectronics     Hybrid Journal   (Followers: 1)
IACR Transactions on Symmetric Cryptology     Open Access   (Followers: 1)
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 102)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 81)
IEEE Embedded Systems Letters     Hybrid Journal   (Followers: 57)
IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology     Hybrid Journal   (Followers: 3)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 52)
IEEE Journal of the Electron Devices Society     Open Access   (Followers: 9)
IEEE Journal on Exploratory Solid-State Computational Devices and Circuits     Hybrid Journal   (Followers: 1)
IEEE Letters on Electromagnetic Compatibility Practice and Applications     Hybrid Journal   (Followers: 4)
IEEE Magnetics Letters     Hybrid Journal   (Followers: 7)
IEEE Nanotechnology Magazine     Hybrid Journal   (Followers: 42)
IEEE Open Journal of Circuits and Systems     Open Access   (Followers: 3)
IEEE Open Journal of Industry Applications     Open Access   (Followers: 3)
IEEE Open Journal of the Industrial Electronics Society     Open Access   (Followers: 3)
IEEE Power Electronics Magazine     Full-text available via subscription   (Followers: 77)
IEEE Pulse     Hybrid Journal   (Followers: 5)
IEEE Reviews in Biomedical Engineering     Hybrid Journal   (Followers: 23)
IEEE Solid-State Circuits Letters     Hybrid Journal   (Followers: 3)
IEEE Solid-State Circuits Magazine     Hybrid Journal   (Followers: 13)
IEEE Transactions on Aerospace and Electronic Systems     Hybrid Journal   (Followers: 369)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 74)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 64)
IEEE Transactions on Autonomous Mental Development     Hybrid Journal   (Followers: 8)
IEEE Transactions on Biomedical Engineering     Hybrid Journal   (Followers: 39)
IEEE Transactions on Broadcasting     Hybrid Journal   (Followers: 13)
IEEE Transactions on Circuits and Systems for Video Technology     Hybrid Journal   (Followers: 26)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 46)
IEEE Transactions on Electron Devices     Hybrid Journal   (Followers: 19)
IEEE Transactions on Geoscience and Remote Sensing     Hybrid Journal   (Followers: 228)
IEEE Transactions on Haptics     Hybrid Journal   (Followers: 5)
IEEE Transactions on Industrial Electronics     Hybrid Journal   (Followers: 75)
IEEE Transactions on Industry Applications     Hybrid Journal   (Followers: 40)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 27)
IEEE Transactions on Learning Technologies     Full-text available via subscription   (Followers: 12)
IEEE Transactions on Power Electronics     Hybrid Journal   (Followers: 80)
IEEE Transactions on Services Computing     Hybrid Journal   (Followers: 4)
IEEE Transactions on Signal and Information Processing over Networks     Hybrid Journal   (Followers: 13)
IEEE Transactions on Software Engineering     Hybrid Journal   (Followers: 79)
IEEE Women in Engineering Magazine     Hybrid Journal   (Followers: 11)
IEEE/OSA Journal of Optical Communications and Networking     Hybrid Journal   (Followers: 16)
IEICE - Transactions on Electronics     Full-text available via subscription   (Followers: 12)
IEICE - Transactions on Information and Systems     Full-text available via subscription   (Followers: 5)
IET Cyber-Physical Systems : Theory & Applications     Open Access   (Followers: 1)
IET Energy Systems Integration     Open Access   (Followers: 1)
IET Microwaves, Antennas & Propagation     Hybrid Journal   (Followers: 36)
IET Nanodielectrics     Open Access  
IET Power Electronics     Hybrid Journal   (Followers: 61)
IET Smart Grid     Open Access   (Followers: 1)
IET Wireless Sensor Systems     Hybrid Journal   (Followers: 18)
IETE Journal of Education     Open Access   (Followers: 4)
IETE Journal of Research     Open Access   (Followers: 11)
IETE Technical Review     Open Access   (Followers: 13)
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems)     Open Access   (Followers: 3)
Industrial Technology Research Journal Phranakhon Rajabhat University     Open Access  
Informatik-Spektrum     Hybrid Journal   (Followers: 2)
Instabilities in Silicon Devices     Full-text available via subscription   (Followers: 1)
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 14)
International Journal of Advanced Research in Computer Science and Electronics Engineering     Open Access   (Followers: 18)
International Journal of Advances in Telecommunications, Electrotechnics, Signals and Systems     Open Access   (Followers: 12)
International Journal of Antennas and Propagation     Open Access   (Followers: 11)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 4)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 5)
International Journal of Control     Hybrid Journal   (Followers: 11)
International Journal of Electronics     Hybrid Journal   (Followers: 7)
International Journal of Electronics and Telecommunications     Open Access   (Followers: 13)
International Journal of Granular Computing, Rough Sets and Intelligent Systems     Hybrid Journal   (Followers: 3)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Hybrid Intelligence     Hybrid Journal  
International Journal of Image, Graphics and Signal Processing     Open Access   (Followers: 16)
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 10)
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields     Hybrid Journal   (Followers: 4)
International Journal of Power Electronics     Hybrid Journal   (Followers: 25)
International Journal of Review in Electronics & Communication Engineering     Open Access   (Followers: 4)
International Journal of Sensors, Wireless Communications and Control     Hybrid Journal   (Followers: 10)
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 4)
International Journal of Wireless and Microwave Technologies     Open Access   (Followers: 6)
International Transaction of Electrical and Computer Engineers System     Open Access   (Followers: 2)
JAREE (Journal on Advanced Research in Electrical Engineering)     Open Access  
Journal of Biosensors & Bioelectronics     Open Access   (Followers: 4)
Journal of Advanced Dielectrics     Open Access   (Followers: 1)
Journal of Artificial Intelligence     Open Access   (Followers: 12)
Journal of Circuits, Systems, and Computers     Hybrid Journal   (Followers: 4)
Journal of Computational Intelligence and Electronic Systems     Full-text available via subscription   (Followers: 1)
Journal of Electrical and Electronics Engineering Research     Open Access   (Followers: 38)
Journal of Electrical Bioimpedance     Open Access  
Journal of Electrical Bioimpedance     Open Access   (Followers: 2)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 7)
Journal of Electrical, Electronics and Informatics     Open Access  
Journal of Electromagnetic Analysis and Applications     Open Access   (Followers: 8)
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 9)
Journal of Electronic Design Technology     Full-text available via subscription   (Followers: 6)
Journal of Electronic Science and Technology     Open Access   (Followers: 1)
Journal of Electronics (China)     Hybrid Journal   (Followers: 5)
Journal of Energy Storage     Full-text available via subscription   (Followers: 4)
Journal of Engineered Fibers and Fabrics     Open Access   (Followers: 2)
Journal of Field Robotics     Hybrid Journal   (Followers: 4)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 190)
Journal of Information and Telecommunication     Open Access   (Followers: 1)
Journal of Intelligent Procedures in Electrical Technology     Open Access   (Followers: 3)
Journal of Low Power Electronics     Full-text available via subscription   (Followers: 10)
Journal of Low Power Electronics and Applications     Open Access   (Followers: 10)
Journal of Microelectronics and Electronic Packaging     Hybrid Journal   (Followers: 1)
Journal of Microwave Power and Electromagnetic Energy     Hybrid Journal   (Followers: 3)
Journal of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 11)
Journal of Nuclear Cardiology     Hybrid Journal  
Journal of Optoelectronics Engineering     Open Access   (Followers: 4)
Journal of Physics B: Atomic, Molecular and Optical Physics     Hybrid Journal   (Followers: 32)
Journal of Power Electronics     Hybrid Journal   (Followers: 2)
Journal of Power Electronics & Power Systems     Full-text available via subscription   (Followers: 11)
Journal of Semiconductors     Full-text available via subscription   (Followers: 5)
Journal of Sensors     Open Access   (Followers: 27)
Journal of Signal and Information Processing     Open Access   (Followers: 8)
Jurnal ELTIKOM : Jurnal Teknik Elektro, Teknologi Informasi dan Komputer     Open Access  
Jurnal Rekayasa Elektrika     Open Access  
Jurnal Teknik Elektro     Open Access  
Jurnal Teknologi Elektro     Open Access  
Kinetik : Game Technology, Information System, Computer Network, Computing, Electronics, and Control     Open Access  
Majalah Ilmiah Teknologi Elektro : Journal of Electrical Technology     Open Access   (Followers: 2)
Metrology and Measurement Systems     Open Access   (Followers: 6)
Microelectronics and Solid State Electronics     Open Access   (Followers: 28)
Nanotechnology, Science and Applications     Open Access   (Followers: 6)
Nature Electronics     Hybrid Journal   (Followers: 1)
Networks: an International Journal     Hybrid Journal   (Followers: 5)
Open Electrical & Electronic Engineering Journal     Open Access  
Open Journal of Antennas and Propagation     Open Access   (Followers: 8)
Paladyn. Journal of Behavioral Robotics     Open Access   (Followers: 1)
Power Electronics and Drives     Open Access   (Followers: 2)
Problemy Peredachi Informatsii     Full-text available via subscription  
Progress in Quantum Electronics     Full-text available via subscription   (Followers: 7)
Radiophysics and Quantum Electronics     Hybrid Journal   (Followers: 2)
Recent Advances in Communications and Networking Technology     Hybrid Journal   (Followers: 3)
Recent Advances in Electrical & Electronic Engineering     Hybrid Journal   (Followers: 11)
Research & Reviews : Journal of Embedded System & Applications     Full-text available via subscription   (Followers: 6)
Revue Méditerranéenne des Télécommunications     Open Access  
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 57)
Semiconductors and Semimetals     Full-text available via subscription   (Followers: 1)
Sensing and Imaging : An International Journal     Hybrid Journal   (Followers: 2)
Solid State Electronics Letters     Open Access  
Solid-State Electronics     Hybrid Journal   (Followers: 9)
Superconductor Science and Technology     Hybrid Journal   (Followers: 3)
Synthesis Lectures on Power Electronics     Full-text available via subscription   (Followers: 3)
Technical Report Electronics and Computer Engineering     Open Access  
TELE     Open Access  
Telematique     Open Access  
TELKOMNIKA (Telecommunication, Computing, Electronics and Control)     Open Access   (Followers: 9)
Transactions on Cryptographic Hardware and Embedded Systems     Open Access   (Followers: 2)

        1 2 | Last   [Sort by number of followers]   [Restore default list]

Similar Journals
Journal Cover
IEEE Transactions on Industry Applications
Journal Prestige (SJR): 1.02
Citation Impact (citeScore): 4
Number of Followers: 40  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0093-9994
Published by IEEE Homepage  [229 journals]
  • IEEE Industry Applications Society
    • Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • IEEE Transactions On Industry Applications
    • Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Information for Authors
    • Abstract: These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Energy Management of Islanded Nanogrids Through Nonlinear Optimization
           Using Stochastic Dynamic Programming
    • Authors: Andres Salazar;Alberto Berzoy;Wenzhan Song;Javad Mohammadpour Velni;
      Pages: 2129 - 2137
      Abstract: Islanded nanogrids (NGs) are autonomous systems consisting of small-scale generation units including renewable energy sources and traditional fuel generators and energy storage systems (ESS) that typically serve few buildings or loads. This work aims at developing and validating a new optimal energy management (EM) algorithm for an islanded NG. To minimize the generator's operating cost and maximize battery availability at each operating cycle, dynamic programming (DP) framework is employed to solve the underlying optimization problem. The goal of the proposed approach is to ensure the use of maximum available solar power and to achieve optimal battery state of charge. To meet that goal, the management of the ESS is formulated as a stochastic optimal control problem, where nonlinearities in the battery discharging process are considered. A Markov model is constructed for predicting the probability distribution of the solar production used in the stochastic DP formulation. Simulation results are given to illustrate the efficacy of the proposed DP-based approach compared to a rule-based algorithm. Finally, a hardware-in-the-loop system is used to evaluate the real-time operation of the proposed EM algorithm.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • DC Arc Flash: Testing and Modeling Incidents in a 125-V Substation Battery
           Backup System
    • Authors: Austin C. Gaunce;Xuan Wu;John D. Mandeville;Dennis J. Hoffman;Amrit S. Khalsa;Joseph Sottile;Ronald J. Wellman;
      Pages: 2138 - 2147
      Abstract: Station batteries used as a backup source to supply station direct-current (dc) power to relays, etc., present a source of personnel exposure to dc arc flash. However, dc arc flash is less understood compared with the arc-flash phenomena that occur in alternating-current (ac) systems. Some models exist to quantify the potential hazards posed by dc electrical systems; however, there is little empirical data available. Additionally, the lower voltage and/or lower capacity station batteries are even less researched. As a result, a series of arc-flash tests were performed at the Dolan Technology Center of American Electric Power (AEP) utilizing two 125 Vdc batteries with rated capacities of 100 and 150 Ah. For these tests, working distance and gap width were used as independent variables. Upon the conclusion of testing, various relationships were analyzed to generate a predictive model for incident energy. This model serves as a compilation of the empirical data collected during testing and will contribute to future research efforts to better understand dc arc-flash incidents from station batteries.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • A Review on Different Aspects of Traction Motor Design for Railway
    • Authors: Shafigh Nategh;Aldo Boglietti;Yujing Liu;Daniel Barber;Ron Brammer;David Lindberg;Ola Aglen;
      Pages: 2148 - 2157
      Abstract: This article presents a review in three parts on the current traction motor topologies available in the railway market. In the first part, essential aspects of the electromagnetic design of railway traction motors, e.g., motor sizing and rotor configurations, are discussed. Different topologies are compared considering the wide range of applications. The pros and cons of each topology in specific applications are highlighted based on the corresponding performance requirements. In the second part, different cooling configurations of traction motors common in railway are reviewed, focusing on the solutions based on air cooling. The third part presents a review of the available insulation systems for traction motors. Two primary insulation systems used in traction applications with thermal classes of H and N are discussed. The focus in this article is placed on the main applications in railway including light rail vehicles, metros, electric multiple units, high-speed trains, and locomotives. Additionally, trends in traction motors development in the coming years are reported separately for electromagnetic, cooling, and insulation designs.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Model-Based Analysis and Quantification of Bearing Faults in Induction
    • Authors: Shen Zhang;Bingnan Wang;Makoto Kanemaru;Chungwei Lin;Dehong Liu;Masahito Miyoshi;Koon Hoo Teo;Thomas G. Habetler;
      Pages: 2158 - 2170
      Abstract: The detection of rolling-element bearing fault can be accomplished by monitoring and interpreting a variety of signals, including the vibration, the acoustic noise, and the stator current. The existence of a bearing fault as well as its specific fault type can be readily determined by performing frequency spectral analysis on the monitored signals with various signal processing techniques. However, this traditional approach, despite being simple and intuitive, is not able to identify the severity of a bearing fault in a quantitative manner. Moreover, it is often times tedious and time-consuming to apply this approach to electric machines with different power ratings, as the bearing fault threshold values need to be manually calibrated for each motor running at every possible speed and carrying any possible load. This article, thus, proposes a quantitative approach to estimate the bearing fault severity based on the airgap displacement profile, which is reconstructed from the mutual inductance variation profile estimated from a quantitative electrical model that takes the stator current as input. In addition, the accuracy of the developed electrical model and the estimated bearing fault severity are validated by the simulation and experimental results, and the explicit airgap variation profile is reconstructed with the superposition of multiple Fourier series terms estimated from the stator current via the proposed scheme. The proposed method offers a quantitative and universal bearing fault indicator for induction machines with any power ratings and operating under any speed and load conditions.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Position Sensorless Control of Synchronous Reluctance Machines Based on
           Magnetic Saturation Depending on Current Phase Angles
    • Authors: Tetsuya Kojima;Toshiki Suzuki;Moriyuki Hazeyama;Shinsuke Kayano;
      Pages: 2171 - 2179
      Abstract: Position sensorless control of synchronous reluctance machines is not easy due to nonlinear correlations caused by extensive magnetic saturation. This article investigates stability of a conventional saliency-based method and, for the first time, shows that the method becomes unstable at high torque with high magnetic saturation not due to cross-coupling effect itself but due to expansion of the cross-coupling effect through feedback of the estimated position. This instability occurs even when neither disappearance of the saliency nor reversal of the estimated d- and q- axes arises. A novel method to overcome this instability is proposed, which utilizes magnetic saturation depending on current phase angles. The proposed method was verified by simulations and experiment using a prototype machine. The results demonstrated that the proposed method achieved stable sensorless operation at the maximum torque, and thus, surpassed the conventional saliency-based method, the feasible torque of which was limited to 60% of the maximum for the prototype machine.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • A Seamless Transition Scheme of Position Sensorless Control in Industrial
           Permanent Magnet Motor Drives With Output Filter and Transformer for Oil
           Pump Applications
    • Authors: Jingbo Liu;Thomas A. Nondahl;Jingya Dai;Semyon Royak;Peter B. Schmidt;
      Pages: 2180 - 2189
      Abstract: This article proposes a position sensorless control scheme for the induction and permanent magnetic low-voltage (LV) motor drives with an output filter and transformer for an electric submersible pump (ESP) and progressive cavity pump (PCP). The proposed sensorless strategy covers the full-speed range for ESP drives. An open velocity loop, current regulated sensorless controller is utilized to drive induction and permanent magnet motors (PMMs) during starting and at low speeds. A field-oriented controller (FOC) that utilizes an estimated rotor position based upon motor back electromotive force (EMF) is utilized to drive the motor at higher speeds. A seamless transition between controllers for the two operational modes, i.e., low-speed control and high-speed control, is proposed in this article. With velocity mode control over the full-speed range and mode control hysteresis, a smooth transition between open loop and EMF-based observer control can be achieved. The sensorless control scheme presented in this article has been implemented in a commercial drive for an ESP (deep well) application.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Electrically Hazardous Jobs in the U.S.
    • Authors: Brett Brenner;James C. Cawley;Daniel Majano;
      Pages: 2190 - 2195
      Abstract: This article examined 1004 U.S. Occupational Safety and Health Administration cases of electrical injury that occurred between January 1, 2011 and June 28, 2017. The data are examined to determine which occupations experienced fatal electrical injury. Characteristics such as the degree of injury, the nature of injury, and task assignments at the time of injury were determined. There were 705 fatal electrical injuries from all causes. There were 17 occupations with ten or more fatal cases, led by, in order, “electricians,” “construction laborers,” “laborers, except construction,” “electrical power installers and repairers,” and “tree trimming occupations.” In addition, the data are also examined to isolate fatal overhead power line injuries. Overhead power lines were involved in 246 fatal electrical shock injuries to workers and ten burn injuries. Occupations most affected by overhead power line injuries were studied in greater detail. Just six occupations account for more than one half of all those fatally injured by electricity in overhead power line cases. Occupations with ten or more fatal overhead power line injuries include, in order, “construction laborer,” “laborers, except construction,” “tree trimming occupations,” “electrical power installers and repairers,” “roofers,” and “truck drivers, heavy.” Several identified occupations with unexpected electrical exposure, such as “roofers,” “tree trimmers,” and “truck drivers,” are not usuall- associated with electrically hazardous jobs. Erecting, moving, and dismantling scaffolding, the use of conductive ladders, booms, and tag lines, and tree trimming in the vicinity of overhead power lines were common scenarios in which the fatal electrical injuries are studied. Working without deenergizing circuits, working without proper prejob hazard analysis and planning, and working without proper personal protective equipment also were mentioned in the accident narratives.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Enhancing Worker and Equipment Protection Through Passive Arc-Fault
    • Authors: Antony Parsons;Timothy Faber;Mark A. Metzdorf;
      Pages: 2196 - 2204
      Abstract: Existing arc flash standards like IEEE 1584 and 1584.1 present models that can be used to estimate incident energy levels in power distribution equipment but provide limited direction regarding how equipment construction should be considered in the calculations. Users performing arc flash risk assessments are left to apply engineering judgment when considering how barriers or isolation of components should be considered. This can lead to risk assessments that are inconsistent or incorrect. Current practices regarding arc flash evaluation in barriered and nonbarriered equipment are reviewed based on current standards. Gaps and potential concerns are discussed, including the lack of defined criteria to use in calculations, along with lack of criteria for determining when barrier systems are considered effective at preventing, mitigating, controlling, or containing arcing faults. A description of a new system that provides passive protection in low-voltage distribution equipment is presented. By providing improved protection for the incoming conductors and main circuit breaker itself, this line-side protection system reduces or eliminates the uncertainties, which allows for more consistent and accurate application of risk assessments. The new protection system enables arc flash protection to be provided by a passive, enclosed system that has been tested to verify performance. As such, the calculations and risk assessment are less reliant on assumptions regarding the performance of the equipment. Practical aspects of arc flash analysis and labeling and operation and maintenance of such equipment are also discussed.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • High-Voltage Arc Flash Assessment and Applications
    • Authors: Albert Marroquin;Abdur Rehman;Ali Madani;
      Pages: 2205 - 2215
      Abstract: This article explores the need for high-voltage arc flash (HVAF) assessment for utility workers who are exposed to the line to line voltages above 15 kV. The regulatory requirements will be discussed including OSHA, NESC, etc., to get an understanding of how utilities consider HVAF. Furthermore, the methods for evaluating HVAF, key driving factors, and rule of thumbs, and HVAF personal protective equipment will be discussed and compared in great detail to aid in the selection of a thermal incident energy evaluation method. The article includes an example application of HVAF assessment using various commercially available software. This example illustrates the importance of performing an HVAF assessment for utility applications and highlights the differences between thermal incident energy evaluation methods and how they can be conservatively applied for situations outside their intended application range.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Real-Time Stochastic Optimization of Energy Storage Management Using Deep
           Learning-Based Forecasts for Residential PV Applications
    • Authors: Faeza Hafiz;M. A. Awal;Anderson Rodrigo de Queiroz;Iqbal Husain;
      Pages: 2216 - 2226
      Abstract: A computationally proficient real-time energy management method with stochastic optimization is presented for a residential photovoltaic (PV)-storage hybrid system comprised of a solar PV generation and a battery energy storage (BES). Existing offline energy management approaches for day-ahead scheduling of BES suffer from energy loss in real time due to the stochastic nature of load and solar generation. On the other hand, typical online algorithms do not offer optimal solutions for minimizing electricity purchase costs to the owners. To overcome these limitations, we propose an integrated energy management framework consisting of an offline optimization model concurrent with a real-time rule-based controller. The optimization is performed in receding horizon with load and solar generation forecast profiles using deep learning-based long short term memory method in rolling horizon to reduce the daily electricity purchase costs. The optimization model is formulated as a multistage stochastic program where we use the stochastic dual dynamic programming algorithm in the receding horizon to update the optimal set point for BES dispatch at a fixed interval. To prevent loss of energy during optimal solution update intervals, we introduce a rule-based controller underneath the optimization layer in finer time resolution at the power electronics converter control level. The proposed framework is evaluated using a real-time controller-hardware-in-the-loop test platform in an OPAL-RT simulator. The proposed real-time method is effective in reducing the net electricity purchase cost compared to other existing energy management methods.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Multitime Scale Coordinated Scheduling for the Combined System of Wind
           Power, Photovoltaic, Thermal Generator, Hydro Pumped Storage, and
    • Authors: Shiwei Xia;Zhaohao Ding;Ting Du;Dongying Zhang;Mohammad Shahidehpour;Tao Ding;
      Pages: 2227 - 2237
      Abstract: Grid connection of intermittent renewable energy, such as wind power and photovoltaic, results in challenges of keeping power balance for power system operation. In order to solve this problem, this article proposed a multitime scale coordinated scheduling model for the combined system of wind power-photovoltaic-thermal generator-hydro pumped storage-battery (WPTHB) by taking advantages of their complementary operation characteristics. The scheduling model is composed of three time scales: the day-ahead scheduling, the 1-h ahead scheduling, and 15-min ahead scheduling. 1) In the day-ahead scheduling, based on the 24-h ahead forecast data of wind-photovoltaic power and load demand (WPL), the optimal power outputs of thermal power units are solved from a mixed-integer linear programming model to achieve the minimal operation cost of thermal units. 2) In the 1-h ahead scheduling, based on power output of thermal units optimized in the day-ahead scheduling and the hourly forecasted WPL, the hydro-pumped unit power outputs are optimally dispatched to minimize their operation cost. 3) In the 15-min ahead scheduling, based on day-ahead optimal power outputs of thermal units and the 1-h ahead optimal outputs of pumped storage, the battery optimal power generation is obtained from an ac optimal power flow model solved by MATPOWER. The simulation of the New England system has validated that the proposed multitime scale coordinated scheduling model could fully explore the distinguished power regulation speed and capacities of thermal power units, hydro-pumped storage, and batteries to effectively track WPL variations and achieve system economic operation simultaneously.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Coordinated Scheduling for Improving Uncertain Wind Power Adsorption in
           Electric Vehicles—Wind Integrated Power Systems by Multiobjective
           Optimization Approach
    • Authors: Yuanzheng Li;Zhixian Ni;Tianyang Zhao;Minghui Yu;Yun Liu;Lei Wu;Yong Zhao;
      Pages: 2238 - 2250
      Abstract: Electric vehicles (EVs) and renewable energy, such as wind power, have been widely utilized to meet the sustainable development of our society. To this end, research articles on the operation performance of the EV-wind integrated power system are important. This article proposes a coordinated scheduling model, which aims to improve the wind power adsorption while considering the energy conservation and emission reduction of thermal generators. Besides, to conduct a comprehensive investigation among these multiple objectives, we formulate the coordinated scheduling model as a multiobjective optimization problem. Then, a multiobjective optimization algorithm based on a parameter adaptive differential evolution is proposed to solve this problem. Simulation results based on a modified Midwestern USA power system verify that the proposed scheduling model could reveal the relationship among multiple objectives, and the integration of EVs can improve the wind power adsorption and cost effectiveness of the power system.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Time–Frequency Feature Combination Based Household Characteristic
           Identification Approach Using Smart Meter Data
    • Authors: Siqing Yan;Kangping Li;Fei Wang;Xinxin Ge;Xiaoxing Lu;Zengqiang Mi;Hongyu Chen;Shengqiang Chang;
      Pages: 2251 - 2262
      Abstract: Household characteristics play an important role in helping utilities carry out efficient and personalized services. Current methods to obtain such information, e.g., surveys, are usually costly and time-consuming. The widespread installation of smart meters enables the collection of fine-grained residential electricity consumption data and thus, making the identification of household characteristics from smart meter data possible. This article proposes a time-frequency feature combination based household characteristic identification approach using smart meter data. First, in addition to conventional time-domain statistical features, several frequency-domain features are extracted using discrete wavelet transform. Second, the random forest algorithm is used to select a subset of important features and remove redundant information contained in the original feature set. Third, a support vector machine is used as a classifier with the input of the selected features to infer the household characteristics. Finally, case study using the realistic data from Ireland indicates that the proposed approach shows better performance after incorporating the frequency-domain features.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • AFLL-Based Control Technique for Grid Interfaced Three Phase PV System
    • Authors: Bhim Singh;Vandana Jain;
      Pages: 2263 - 2272
      Abstract: This work deals with an advanced frequency locked loop (AFLL)-based control algorithm for a three phase double stage grid interfaced solar photovoltaic (PV) system. This AFLL-based algorithm extracts fundamental component of the load current and eliminates harmonics, performs grid currents balancing, improves the system performance during distorted grid conditions, and isolates the system during the occurrence of a grid fault. In a long radial network, the far away ends have the problem of voltage quality but this controller maintains the grid power quality by providing required reactive and active powers to the grid. The voltage source converter (VSC) of the PV system supplies the PV energy to the grid even under the worst situations of dc offset, solar insolation variation, load unbalancing, grid faults, voltage distortion, voltage unbalance, and voltage swell/sag. The VSC switching losses are reduced using an adaptive dc link voltage. This system is modeled and simulated in MATLAB and tests are conducted on a prototype built in the research laboratory under various odd states as stated earlier. Even during the disturbance, the harmonics level in the grid currents is seen in limits as suggested in the IEEE Standard-519.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Wind Farm Dynamic Equivalent Modeling Method for Power System
           Probabilistic Stability Assessment
    • Authors: Peng Wang;Zhenyuan Zhang;Qi Huang;Wei-Jen Lee;
      Pages: 2273 - 2280
      Abstract: The uncertainty of power system is intensified by the integration of large-scale renewable energy resources such as wind farm (WF). Considering the impact of system uncertainties, the probabilistic stability analysis methods have been used in the stability assessments of power system with the WF integration. However, in traditional probabilistic analysis methods, WF is normally considered as PQ bus or aggregated as one single-machine equivalent model regardless of wake effect, which might reduce the accuracy of probabilistic stability studies. In this article, a dynamic equivalent modeling method of WF for probabilistic stability assessments is proposed. The wake effect is considered in the modeling process and a practical four-machine clustering method is used in wind turbines clustering. Besides, the fisher discriminant analysis (FDA) is adopt to combine the similar WTs clustering results reasonably. Then, the WF is aggregated to a multi-machine equivalent model by capacity weighted method. Also, the established WF probabilistic model can be directly used in time-domain simulation based on Monte Carlo simulation and FDA. Finally, the efficiency of the proposed method is verified in an actual WF in China.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Optimized Frequency Scanning of Nonlinear Devices Applied to
           Subsynchronous Resonance Screening
    • Authors: Igor Brandão Machado Matsuo;Farshid Salehi;Long Zhao;Yuhao Zhou;Wei-Jen Lee;
      Pages: 2281 - 2291
      Abstract: Frequency scanning is a powerful and versatile approach for subsynchronous resonance (SSR) screening in power grids. Among different numerical and analytical frequency scanning techniques, the harmonic injection method is well suited for the scan of black-box models with active elements, such as in wind farms and solar plants. The results can be used for SSR risk assessment, in which accuracy performs a decisive role. The ideal situation for this method, which leads to the most accurate results, is to perform one simulation per single-frequency injection. However, for SSR studies with a wide range of frequencies and simulations with very small time steps (scale of μs), this comes at the expense of increased simulation time. This article proposes a technique to improve the accuracy of the harmonic injection method through the optimization of the crest factor while injecting all frequencies at one shot, therefore also reducing simulation time. The proposed technique was tested on a wind farm connected to a radial test case and on a portion of a Texas synthetic grid with multiple active elements, including two wind farms and a VSC-based STATCOM. The frequency scan results were benchmarked with both time-domain transient simulations and the ideal multiple single-frequency injection case and compared with other techniques. The results show that the proposed method is superior in accuracy when compared to the other techniques and is 11.71 times faster when compared to multiple single-frequency injections.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • A New Approach for Estimating Frequency Variations Due to Smart Grid
    • Authors: Saleh A. Saleh;Jeffery Wo;Xavier F. St-Onge;Eduardo Castillo-Guerra;
      Pages: 2292 - 2303
      Abstract: This article presents a new approach for estimating the frequency variations (Df) due to applying smart grid functions on a load bus. The proposed approach is based on constructing a ZIP model for the power demands at a load bus that is controlled by smart grid functions.The constructed ZIP model provides a relationship between the active and reactive power demands and the frequency at any load bus. This relationship can be formulated as a set of nonlinear equations, which can be numerically solved for Df. The load-model approach is implemented for performance evaluation using load buses in the IEEE 30-bus power system under different loading levels. Performance results show that the proposed approach has a simple implementation, and can provide an accurate estimation of frequency variations due to slow and small changes load power demands. Furthermore, performance results reveal the insensitivity of the load-model approach to load power demands and/or seasonal changes in load power demands.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Seismic-Resilient Electric Power Distribution Systems: Harnessing the
           Mobility of Power Sources
    • Authors: Zijiang Yang;Payman Dehghanian;Mostafa Nazemi;
      Pages: 2304 - 2313
      Abstract: Mobile power sources (MPSs), including mobile emergency generators, truck-mounted mobile energy storage systems, and electric vehicles, have great potentials to be employed as grid-support resources during power grid emergency operating conditions to supply the critical loads and enhance the resilience of distribution system (DS) via a swift disaster restoration. We here investigate the MPS dispatch (i.e., routing and scheduling) in coordination with DS dynamic network reconfiguration. We propose a two-stage restoration scheme to facilitate the DS restoration following the high-impact low-probability (HILP) seismic disasters. In the first stage, a seismic hazard is simulated through a Monte Carlo simulation engine to estimate the unavailability of power distribution branches under a suite of seismic force scenarios. In the second stage, a mixed-integer nonlinear programming (MINLP) optimization model is formulated for DS restoration that cooptimizes the routing and scheduling of MPSs and DS dynamic network reconfiguration. The MINLP model is then linearized to a mixed-integer linear programming model to reduce the computation complexity, where the seismic-resilience recovery strategies are generated at different timescales. The efficacy of the proposed method is evaluated on the IEEE 33-node test system and the results verify a significant reduction in the load outages and an improved power system resilience to HILP earthquakes.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Bilevel Programming Approach for Optimal Planning Design of EV Charging
    • Authors: Bo Zeng;Houqi Dong;Fuqiang Xu;Ming Zeng;
      Pages: 2314 - 2323
      Abstract: This article proposes a new methodological framework to optimize the planning design of an electric vehicle (EV) charging station with renewable energy resources (RCS). Differing from extant studies, the proposed approach explicitly considers the strategic self-interested nature of EV users under a fully liberalized market environment and aims at fully exploiting the flexibility of EV charging loads to enhance the efficiency of renewable energy utilization. Such a problem has been formulated as a bilevel programming model with equilibrium constraints. In this formulation, the upper level problem determines the optimal configuration of the RCS and its operation/pricing schemes simultaneously to maximize the total profits of RCS owner, while the lower level models the strategic charging decisions of EV users in response to the provided pricing scheme of RCS owner. The resulting bilevel optimization model is reformulated into an equivalent single-level linear program, by replacing the lower level problem with Karush-Kuhn-Tucker conditions and linearizing the bilinear products via McCormick relaxation and Big-M technique. The simulation results from case studies demonstrate the effectiveness of the proposed methodology.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Single- and Multi-Fault Diagnosis Using Machine Learning for Variable
           Frequency Drive-Fed Induction Motors
    • Authors: Mohammad Zawad Ali;Md Nasmus Sakib Khan Shabbir;Shafi Md Kawsar Zaman;Xiaodong Liang;
      Pages: 2324 - 2337
      Abstract: In this article, an effective machine learning-based fault diagnosis method is developed for induction motors driven by variable frequency drives (VFDs). Two identical 0.25 HP induction motors under healthy, single-, and multifault conditions were tested in the lab with different VFD output frequencies and motor loadings. The stator current and the vibration signals of the motors were recorded simultaneously under steady-state for each test, and both signals are evaluated for their suitability for fault diagnosis. The signal processing technique, discrete wavelet transform, is chosen in this article to extract features for machine learning. Four families of machine learning algorithms in the MATLAB Classification Learner Toolbox, decision trees, support vector machines, k-nearest neighbors, and ensemble, with 20 classifiers are evaluated for their classification accuracy when used for fault diagnosis of induction motors fed by VFDs. To allow fault diagnosis for untested motor operating conditions, the feature calculation formulas are developed through surface fitting using experimental data of a range of tested frequencies and loadings of the motor to provide training data for untested conditions.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Smart Tunnel and Dynamic Risk Analysis
    • Authors: Alessandro Focaracci;Giacomo Greco;Luigi Martirano;
      Pages: 2338 - 2347
      Abstract: The article proposes an innovative system of supervision and data acquisition, oriented to fire safety through a dynamic risk analysis, called supervisory control and dynamic risk analysis (SCADRA). SCADRA achieves operation and management benefits for safety, functionality, and energy optimization, by means of dynamic control and monitoring measures. A “Smart Tunnel” can be defined as a model where technical systems are designed and installed in an advanced way, by using digital components and sensors. SCADRA has been developed to offer a complete tool (human machine interface) for real-time monitoring of tunnel safety by tunnel operators, integrated with the innovative dynamic risk analysis. SCADRA offers compensatory and/or supplementary safety measures for emergency management and supports fire rescue teams that are operating in tunnel in which some requirements could not be realized.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Impact of Generation Flexibility on the Operating Costs of the Taiwan
           Power System Under a High Penetration of Renewable Power
    • Authors: Yuan-Kang Wu;Wen-Shan Tan;Si-Ru Huang;Yu-Shuang Chiang;Chui-Pin Chiu;Chun-Lien Su;
      Pages: 2348 - 2359
      Abstract: The penetration of renewable energy is gradually increasing. Therefore, power system flexibility, which is required to maintain system security and to cope with renewable generation uncertainty, becomes more important. Various technologies, such as flexible generators, demand management, energy storage, network reconfiguration, and even efficient system operations, are capable of improving power system flexibility. Nevertheless, among them, flexible generation resources can provide a direct way to enhance the power system flexibility. This article first applies the fuzzy analytic hierarchy process to calculate the flexibility index of generation resources. Then, the process of unit scheduling is implemented under various operation scenarios to investigate the relationship between the generation flexibility and the cost of unit scheduling. Finally, the required flexibility and the corresponding capacity of flexible generators under a specified penetration of renewable power generation are investigated under different operation scenarios.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Development of an Equivalent Wind Farm Model for Frequency Regulation
    • Authors: Yuan-Kang Wu;Jyun-Jie Zeng;Guan-Liang Lu;Shiu-Wu Chau;Yen-Cheng Chiang;
      Pages: 2360 - 2374
      Abstract: The operational security of power systems for wind farm (WF) integration becomes more important as the penetration of wind generation increases. A WF may contain hundreds of wind turbines (WT) and thus the power system simulations based on the complex model of a WT consume much time. This article proposes an equivalent WF model with the frequency-regulation function. The main research works include the establishment of the generic model of a WT, the development of single- and multimachine equivalent models for a large WF, the clustering of WTs based on the developed nonlinear wake model and the fuzzy C-means (FCM) clustering algorithm, the integration of the frequency-regulation function into the equivalent WF model, and the validation of the developed equivalent WF model by various operating scenarios. The results demonstrate that the proposed multimachine equivalent method based on the FCM clustering provides a more accurate model than a single-WT equivalent model. Consequently, the research results provide a solution for simulating a large-scale wind power integration, providing efficient, accurate, and fast steady-state and dynamic analyses.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Numerical Formulation to Evaluate the Coupling by the Soil Among Multiple
           Grounding Electrodes: A High-Voltage Substations Application
    • Authors: Daniel S. Gazzana;Alex B. Tronchoni;Roberto Chouhy Leborgne;Marcos Telló;Arturo S. Bretas;
      Pages: 2375 - 2381
      Abstract: This article presents a methodology to calculate grounding potentials in adjacent electrodes present in high-voltage substations subjected to a short-circuit current dissipated in the main grid. The contribution of the technique is the consideration of the coupling by the soil among electrodes taking into account a two-layer soil and irregular geometry of the conductors. This problem is of special concern due to the presence of passers-by near metallic fences, not directly connected to the grounding grid, whose potentials usually have not been evaluated. In this context, the article presents a general analytical formulation aiming to estimate the potential in multiple electrodes, leading to a possible risk to human beings close to the substation. Sensitivity studies are performed in order to evaluate the effect of the soil resistivity and the distance from the faulted grid and the coupled electrode. A practical application in a substation grounding system is discussed. Finally, a huge grounding system is evaluated in order to verify the robustness of the proposed formulation.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Experimental Validation of High-Performance HIL-Based Real-Time PMU Model
           for WAMS
    • Authors: Mahmoud Amin;Ahmed Al-Durra;Wafa Elmannai;
      Pages: 2382 - 2392
      Abstract: This article presents a novel real-time hardware-in-loop-based model for synchronized phasor measurement unit (PMU) which incorporates an adaptive observer to estimate the phasor quantities of the actual hardware-based PMU model. The proposed model is feasible for a wide-area monitoring system (WAMS) in modern power grids. The performance of the proposed model is compared to the conventional algorithms of the performance (P)-class and measurement (M)-class PMU models in terms of total vector error and rate of change of frequency under different scenarios (frequency ramp, unbalance with interharmonics, and out-of-bound offnominal frequency). The main advantages of the proposed model compared to existing models are as follows: (1) combining the advantages of both P and M classes in terms of achieving required standard steady-state performance (IEEE C37.118-2005) while capturing the dynamic system performance, (2) improving the redundancy due to PMU loss, (3) allowing faster implementations and advanced visualization tools, and (4) enhancing WAMS accuracy performance. Despite the advantageous introduced utilizing the proposed model, there is still a tradeoff gap between the investment cost of the installed hardware-based PMUs and system redundancy. Moreover, a laboratory-scale six-bus setup is built and tested to demonstrate the practical validity of the proposed model.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Reverse Power Flow (RPF) Detection and Impact on Protection Coordination
           of Distribution Systems
    • Authors: Juan Pablo Holguin;David Celeita Rodriguez;Gustavo Ramos;
      Pages: 2393 - 2401
      Abstract: Due to the inclusion of distributed generation (DG) in modern power systems, there are certain changes in the distribution and transmission stage, either by impedance reflected by the lines, the increase of short-circuit currents, or the X/R relation, seen from the different nodes on the grid. Such changes have a direct impact on protection coordination, which is the priority of study in this article, but it is important to note that another characteristic affected by the DG is the power quality in terms of voltage sags, swells, and harmonics. One of the significant impacts due to the DG is the reverse power flow (RPF), which generally occurs when the generation of a distributed electric power plant exceeds the local load demand, causing power to flow in the opposite direction to normal. This phenomenon can be produced by the intermittency in the renewable energies, which depends on climatic factors. The consequences can be evidenced in the power system with voltage peaks; therefore, the sensitivity and various parameters of protection coordination are critically affected, which has further implications in the power quality. This work proposes a tool to identify possible scenarios of RPFs and a feasible solution is introduced. A comparative assessment is done to minimize the possibility of an RPF in the IEEE 13 Nodes radial system with conclusive results.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • An Approach for Out-of-Step Protection Based on Swing Center Voltage
           Estimation and Analytic Geometry Parameters
    • Authors: Juan R. Camarillo-Peñaranda;David Celeita;Mario Gutierrez;Mateo Toro;Gustavo Ramos;
      Pages: 2402 - 2408
      Abstract: Out-of-step protection has been widely studied, and it remains an important topic in the field. Given the crucial modernization of the power systems and the evolution of protective relaying, it is crucial to merge from traditionally fixed parameters to novel approaches that allow flexibility and possible time-domain protection. This article presents a new methodology to implement an out-of-step protection algorithm through the geometrical understanding of a power system oscillation using Clarke's transformation. The article is an extension of a virtual relay solution previously developed and improves the swing center voltage solution in the αβ plane with enhanced selectivity. The result brings a functional virtual relay capable of detecting and reacting under stable and unstable power swing events through playback techniques. The contribution of this article relies on the application of the time-domain approach to improving the function ANSI 78 as an extension of ongoing research on virtualization of power system protection and real-time prototyping.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Improved Approach to High-Frequency Current Injection-Based Protection for
           Grounding Electrode Line in High-Voltage Direct Current System
    • Authors: Yufei Teng;Zhenyuan Zhang;Xiaopeng Li;
      Pages: 2409 - 2417
      Abstract: High-frequency current injection-based protection is widely used for fault detection of a grounding electrode line in high-voltage direct current (HVdc) system. Since the grounding electrode line is several times longer than the wavelength of the injected current, the relationship between the measured impedance and fault distance is very complex. Due to the complex impedance characteristic, the current injection-based protection has a dead zone under some circumstances. To eliminate the protection dead zone, an improved approach to high-frequency current injection-based protection was proposed. First, the characteristics of the high-frequency impedance of the grounding electrode line under different fault conditions were investigated. Analysis results showed that when the line length was close to the integer multiple of the half-wavelength of the injected current, the measured impedance of the grounding electrode line may be the same as normal operation impedance. Thus, the current injection-based protection will be unable to recognize the fault. Second, a two-layer optimum method was proposed to select the frequency of the injected signal. With the new frequency, the current injection-based protection was able to eliminate the dead zone of the traditional protection. Finally, a ±800-kV HVdc simulation model was constructed, and the simulation results verified the accuracy of our conclusions and the effectiveness of our proposed protection method.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Experiences on Remediation of Special Protection System for Kinmen Power
           System in Taiwan
    • Authors: Ching-Jung Liao;Yen-Feng Hsu;Yung-Fu Wang;Sheng-Huei Lee;Yu-Jen Lin;Chia-Chi Chu;
      Pages: 2418 - 2426
      Abstract: The isolated power system in Kinmen Island, Taiwan has already implemented the special protection system (SPS) to prevent various critical contingencies that occurred during the past decade. However, when a severe N-2 contingency occurred on July 26, 2013, the SPS has not properly armed its under-frequency load shedding. After reexamining transient recorded waveforms, it was observed that the system still has sufficient spinning reserve and the coordination between the under-frequency relay and the current SPS was not well considered. In this article, the current SPS is further modified in order to avoid the occurrence of the excessive load shedding under similar N-2 contingencies. Extensive time-domain dynamical simulations are performed first to study the relationship between the amount of the load shedding and frequency deviations under these extreme N-2 contingencies. Based on these simulation results, the remediation scheme of the SPS will be proposed by modifying the existing SPS design logic and the amount of load shedding. More comprehensive input triggered states are proposed for identifying these severe N-2 contingencies. Both simulation verifications under the proposed remedial scheme and actual transient recorded waveforms under a severe contingency after commissioning this remediated SPS are provided to demonstrate the effectiveness of this proposed remediation scheme.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Influence of Load Characteristics on Three-Phase Short Circuit and
           Demagnetization of Surface-Mounted PM Synchronous Motor
    • Authors: Lijian Wu;Yidong Du;Zekai Chen;Yuliang Guo;Hui Wen;Youtong Fang;
      Pages: 2427 - 2440
      Abstract: Three-phase short circuit (3PSC) is a critical condition that may cause irreversible demagnetization of surface-mounted permanent magnet synchronous motor (SPMSM). In the literature, 3PSC current was often calculated under constant rotor speed condition. However, due to the disturbance of current and electromagnetic torque during 3PSC, the rotor speed usually changes, which influences 3PSC current and electromagnetic torque in turn. This article investigates the 3PSC responses and demagnetization of SPMSM under typical types of loads, such as gravitational lift torque (GLT) load, dry fiction torque (DFT), viscous friction torque (VFT), torque square of speed (TSS), and constant power (CP) load etc. It shows that different load types can lead to different 3PSC responses and demagnetization. Moreover, since the d-axis short circuit (SC) current is more detrimental to demagnetization, this article focuses on the influence of different load characteristics on the d-axis peak SC current. The investigation shows that the d-axis peak current under GLT load can be larger or smaller than that under constant speed load, whereas the 3PSC currents under DFT, VFT, TSS, and CP loads are all smaller than that under constant speed load. In addition, the influence of initial q-axis current, temperature, and machine dimension on the d-axis peak SC current is also investigated. According to the analysis results, some guidelines are given for the demagnetization check when designing an SPMSM. Furthermore, experiments are conducted to validate the theoretical analysis.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Improvement of Starting Performance for Line-Start Permanent Magnet Motors
           by Winding Reconfiguration
    • Authors: Mengxuan Lin;Dawei Li;Yu Zhao;Xiang Ren;Ronghai Qu;
      Pages: 2441 - 2450
      Abstract: Line-start permanent magnet (LSPM) machines have significant advantages in efficiency and power factor compared with regular induction motors; however, the poor starting torque and synchronization capability prevent the widespread of LSPM machines. In this article, winding reconfiguration methods are proposed to improve the starting performance and steady-state performance of LSPM machines. The turns-changing method is to increase asynchronous torque by reducing coil turns in starting, and the pole-changing method is to reduce and even eliminate the permanent magnet (PM) braking torque by changing the pole pair number of stator windings in the early starting period. Both of them can be adopted for an LSPM machine simultaneously to improve average torque in the starting stage. The starting performance is also compared between the turns-pole-changing LSPM machine and pole-increasing LSPM machine. Finite-element analysis is carried out to show the performance differences of LSPM machines using different starting strategies. A turns-changing LSPM machine is also manufactured and tested to validate the starting improvement.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Modeling of Mutually Coupled Switched Reluctance Motors Based on Net Flux
    • Authors: Siddharth Mehta;Md Ashfanoor Kabir;Iqbal Husain;Prerit Pramod;
      Pages: 2451 - 2461
      Abstract: Modeling and accurate estimation of mutual flux in switched reluctance motors are complex due to interphase flux interactions, magnetic saturation, and harmonics. The mutual flux contributes significantly toward torque production of mutually coupled switched reluctance motors (MCSRMs); therefore, their accurate modeling directly influences the control design. In this article, a net-flux-based machine model is proposed to model MCSRMs. The model utilizes dual-phase excitation and multiphase excitation methods to generate the flux lookup tables from the finite-element model of the MCSRM. The modeling process is simple, as it does not require the segregation of the self- and mutual flux components, and machine performance can be predicted accurately using the net flux. The proposed modeling method is validated by implementing it for a fully pitched and concentrated-wound MCSRM and evaluating accuracy against the finite-element method. Details of the developed model are presented along with its comparison with existing methods. A prototype of a fully pitched MCSRM has been built, and the model is validated experimentally. Results show that the proposed model has excellent accuracy even under saturated operating conditions.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Permanent Magnets Aging in Variable Flux Permanent Magnet Synchronous
    • Authors: Daniel Fernández;Maria Martinez;David Reigosa;Juan M. Guerrero;Carlos Manuel Suarez Alvarez;Fernando Briz;
      Pages: 2462 - 2471
      Abstract: Permanent magnet synchronous machines (PMSMs) operation above base speed is typically achieved by injecting negative d-axis current to produce flux weakening. However, this mode of operation increases copper, stator/rotor core, and permanent magnet (PM) losses, penalizing the efficiency and increasing the risk of demagnetization. Variable flux PMSMs in which PMs are magnetized/demagnetized during normal operation of the machine have been proposed to avoid the use of flux weakening current. However, PM aging due to magnetization/demagnetization cycles has not been thoroughly studied yet. This article analyzes the variation of NdFeB, SmCo, and AlNiCo PMs properties, including magnetic, electric, and thermal, resulting from magnetization/demagnetization cycles.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Winding Thermal Modeling and Parameters Identification for Multithree
           Phase Machines Based on Short-Time Transient Tests
    • Authors: Paolo Pescetto;Simone Ferrari;Gianmario Pellegrino;Enrico Carpaneto;Aldo Boglietti;
      Pages: 2472 - 2480
      Abstract: Short-time thermal transient identification method was successfully adopted to evaluate the winding thermal parameters of induction motors for industry applications. In this work, the modeling approach and the identification methodology are extended to the more sophisticated case of multiple three-phase machines. The generalized model takes into consideration the mutual heat exchange between the windings as well as the possible causes of temperature mismatch. A complete procedure to evaluate the parameters of the modified model is provided, supported by experimental validation on a 7.5 kW machine with two three-phase windings in contact at slot level. The method covers any type of multiple three-phase machines, whatever the thermal promiscuity of the winding sets: From deep coupling as the ones presented, to the case where only the end-turns are in contact, to the completely decoupled case. The proposed technique can be useful for the machine design and for real-time temperature monitoring during operation.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Adjustment of Rated Current and Power Factor in a Synchronous Reluctance
           Motor Optimally Designed for Maximum Saliency Ratio
    • Authors: Stjepan Stipetic;Damir Zarko;Niksa Cavar;
      Pages: 2481 - 2490
      Abstract: This article analyzes an engineering problem of adjusting the rated current of a synchronous reluctance motor to match the rated current of a commercially available inverter. This situation may occur when a synchronous reluctance motor is optimally designed for maximum torque per ampere (MTPA) operation using standard IEC stator frames for induction motors. When the motor has a maximized saliency ratio along with MTPA control at rated speed and available inverter voltage, it often happens that rated current of the motor exceeds the rated current of a commercially available inverter. This article shows that the motor current can be reduced and power factor increased by choosing different number of turns per coil and even changing the stack length. In other words, rewinding and axial scaling of the motor is performed in order to retain the same rated voltage and shaft power and hence to operate with better power factor which means lower current and lower kVA requirement. This comes with a certain increase in slot current density and therefore reduction of motor efficiency. All the design tradeoffs, which emerge in this situation and their effects on the motor performance are explained using a linear model of the motor based on a phasor diagram with constant inductances. The predictions of the simple analytical model were confirmed by utilizing flux linkage versus current maps obtained from nonlinear finite element analysis and afterward by conducting measurements on two identical motors wound with different number of turns per coil.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Proposition for Improving the Design of Motor Windings for Low-Pressure
    • Authors: Daniel Roger;Sonia Ait-Amar;Ewa Napieralska-Juszczak;Piotr Napieralski;
      Pages: 2491 - 2499
      Abstract: A new approach is proposed for designing coils free of partial discharges (PDs) for compact machines operating at high altitudes. The proposed method consists in using an enameled wire made with a thin additional resistive layer on the outer surface, which strongly reduces the electrical field in the voids between the wires of random coils. With such a wire, PDs occur only in specific zones situated near the wire connections and a local reinforcement of the insulation can strongly increase the partial discharge inception voltage. The article proposes a theoretical method for determining the properties of the resistive layer. The local reinforcement of the insulation is analyzed with an electrostatic simulation and Paschen's law. Measurements confirm the effectiveness of the proposed method.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Performance Evaluation of an Electromagnetic Free Piston Compressor
           Without Permanent Magnets
    • Authors: David Rafetseder;Wolfgang Amrhein;Florian Poltschak;
      Pages: 2500 - 2509
      Abstract: The performance of a linear free piston gas compressor is investigated in this study. Two compressor pistons are mounted on a robust reciprocating cage mover, which is driven by a double-stator linear induction machine. Since the beginning of the 21st century, many permanent-magnet machines were investigated due to their high power density and efficiency. Less attention has been paid to linear induction machines (LIMs) that stand out through the fact that they do not require expensive rare-earth magnets, and moreover, they are insensitive to strong magnetic fields, high temperatures, and harsh working conditions. This enables them to be used with corrosive media, e.g., for a hydrogen compressor. Therefore, a prototype of a potentially more robust electromagnetic free piston gas compressor was built. It is evaluated on two test benches: First, the LIM is tested with a load motor that enables the measurement of the mechanical output power, and second, the free piston gas compressor is tested with ambient air and the discharge pressure and output flow rate are measured. The electrical power consumption, the mechanical output power of the linear motor, and the pneumatic output power of the free piston compressor are determined for various operating conditions. The measurement results are presented and the average cycle efficiencies are calculated. Moreover, the average cycle power losses of the LIM are analyzed.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Additive Manufacturing of Shaped Profile Windings for Minimal AC Loss in
           Electrical Machines
    • Authors: Nick Simpson;Dominic J. North;Suzanne M. Collins;Phil H. Mellor;
      Pages: 2510 - 2519
      Abstract: Metal additive manufacturing enables production of copper and aluminium parts exhibiting unmatched geometric freedom, giving rise to new possibilities in the winding design of electrical machines and wound passive components. Early adopters of additive manufacturing are primarily concerned with improving power-density or efficiency by increasing slot fill-factor, optimizing end-winding topology or incorporating cooling channels into the conductors. In this article, a method of minimizing the elevated ac loss present in open slot electrical machine topologies is presented, in which individual conductor profiles are shaped according to their magnetic environment. Such shaped profile windings are shown to exhibit operating mode dependent loss behavior giving them potential for efficiency improvement in applications with a dominant operating mode such as electric vehicle traction, aerospace propulsion fans, and generators. For the first time, the conductor shaping method and associated benefits are demonstrated by the retrospective design, additive manufacture, and experimental test of a three-phase set of shaped profile windings for a concentrated wound, open slot, permanent magnet electrical machine.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Space-Shifted Wye–Delta Winding to Minimize Space Harmonics of
           Fractional-Slot Winding
    • Authors: Md Sariful Islam;Md Ashfanoor Kabir;Rajib Mikail;Iqbal Husain;
      Pages: 2520 - 2530
      Abstract: A space-shifted wye-delta winding for fractional-slot concentrated winding (FSCW) is proposed that can simultaneously cancel both sub- and super-order harmonics of its stator MMF. The new winding concept proposes two sets of three-phase windings by doubling the number of stator slots connected in the wye-delta configuration. These two winding sets are shifted in space with respect to each other and are connected in series. The wye-delta configuration eliminates subharmonics and enhances the torque-producing component, whereas their relative shifting angle eliminates the dominant higher order harmonics to provide a cleaner and enhanced MMF spectrum. In FSCW motors, dominant space harmonics other than the torque-producing component give rise to undesirable losses in the magnet and rotor core. The efficacy of the proposed method is demonstrated through its stator MMF, harmonic spectrum, and motor performance using finite-element analysis. The application of the proposed winding to a permanent magnet (PM) machine showed dominant sub- and super-order harmonics cancellation, total harmonic distortion reduction, and magnetic loss reduction along with torque density and power factor improvements. A prototype PM machine is built, and the performance of the proposed concept is verified experimentally.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Design Considerations for an Active–Reactive Induction Motor for
           Medium-Voltage Applications
    • Authors: Jose Titus;Kamalesh Hatua;
      Pages: 2531 - 2540
      Abstract: The active-reactive induction motor (ARIM) has been introduced in the literature as a low-cost and high-efficiency alternative to the synchronous motor in load commutated inverter (LCI) fed drives. ARIM is a squirrel cage machine with two sets of dissimilar three-phase stator windings. While one winding is rated for high voltage and power, the other winding is rated for a lower voltage and power. The low-voltage winding fed from a voltage source inverter (VSI) supplies only reactive power to the machine such that a leading power factor appears at the high-voltage terminals, enabling LCI-fed operation at this winding. Since the ARIM is fundamentally an induction motor, the conventional induction machine design process is applicable. However, due to the nonconventional arrangement of stator windings and being intended specifically for an LCI-fed topology, this new class of induction machines requires some critical design considerations. It is shown in this article that the leakage inductances play a pivotal role in determining the ratings of the low-voltage windings and the VSI. Therefore, an iterative design procedure to obtain the correct ratings for the flux winding and the low-voltage components is proposed. It is also required to know the correct value of the leakage inductance in order to design the control loops for reliable operation. This article proposes experimental methods to determine these leakage inductances. The proposed methods are validated by designing a 3.3-kV, 75-kW prototype and experimental results are presented.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Surge Test-Based Identification of Stator Insulation Component With
           Partial Discharge Activity for Low Voltage AC Motors
    • Authors: Sang Bin Lee;Alireza Naeini;Shesha Jayaram;Greg C. Stone;Mladen Šašić;
      Pages: 2541 - 2549
      Abstract: Partial discharge (PD) has been identified as one of the root causes of stator insulation failure even for low voltage (LV) ac motors. For reliable operation of variable frequency drive motors, a standard acceptance test procedure (IEC STD 60034-18-41) to ensure PD-free operation of LV motors was developed. Although the test can verify whether PD exists in the stator for a surge with predetermined voltage level and risetime, the information on where PD activity is present in the stator insulation is not provided. In this article, a test method based on a new variable risetime surge generator is proposed for identifying the component of stator insulation where PD occurs in LV random wound stators. The proposed test allows the user to locate whether PD is in the turn, phase, or ground insulation. This information is critical for lowering the PD inception voltage for improving the motor reliability through insulation system design/manufacturing or motor/drive system reconfiguration. The test is implemented with a 4.5 kV variable risetime surge generator prototype, and seven LV ac motors are tested to show where PD is likely to occur in commercial LV motors.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Conveyor System With a Highly Integrated Permanent Magnet Gear and Motor
    • Authors: Simon Staal Nielsen;Rasmus Koldborg Holm;Peter Omand Rasmussen;
      Pages: 2550 - 2559
      Abstract: Magnetic gears have attracted increasing attention in recent years due to many possible advantages over mechanical gears. Many papers have been presented with theoretical proof of the basic properties and topologies of the magnetic gears and their parallels to mechanical counterparts. However, very little work has been done to implement the magnetic gears into actual applications which fully utilizes their desirable properties. This article presents a concept study and physical demonstrator of a magnetic gear and permanent magnet machine highly integrated into a drive unit for chain conveyor systems. Several current mechanical gear/motor combinations are replaced by the new drive unit, which is more compact and potentially more energy efficient. Moreover, the inherent overload protection of the magnetic gear eliminates the need for a mechanical slip clutch in the system, further reducing system complexity and improving reliability. An experimentally measured torque density of 142 N·m/L is obtained for the active magnetic gear volume.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Overload Capability of Multiphase Machines Under Normal and Open-Phase
           Fault Conditions: A Thermal Analysis Approach
    • Authors: Aldo Boglietti;Iustin Radu Bojoi;Sandro Rubino;Marco Cossale;
      Pages: 2560 - 2569
      Abstract: Multiphase drives are convenient for high-power/high-current applications as they allow the reduction of the phase current for given rated power and phase voltage. Due to their redundant structure, the multiphase drives have intrinsic open-phase fault-tolerant operation capability. This situation may happen when one or more power electronic units are turned off after a fault event, and the drive configuration allows phase disconnection. In this case, the healthy machine phases can be overloaded to keep the torque constant and without any pulsations. The goal of the work is the evaluation of the thermal parameters of the stator windings of multiphase machines to be used in the analysis of both short thermal transients and steady-state operation, during normal and open-phase faults. The approach has general validity and can be applied to any ac multiphase machine having a distributed winding configuration. The prototype used for the experimental tests is an asymmetrical 12-phase induction machine, having four 3-phase stator sets with isolated neutral points. The stator windings thermal model is obtained experimentally, by considering the mutual heat exchange phenomena among the windings when one or more winding sets are disconnected. This thermal model allows at evaluating the proper machine overloading for short thermal transients and steady-state operation in case of open-phase faults.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Design and Performance Comparison of Vernier and Conventional PM
           Synchronous Wind Generators
    • Authors: Pushman M. Tlali;Rong-Jie Wang;Stiaan Gerber;Christoff Daniel Botha;Maarten J. Kamper;
      Pages: 2570 - 2579
      Abstract: In recent years, the permanent magnet vernier machine (PMVM) has attracted much attention in the research community. Many studies have shown that PMVMs possess superior torque density and are suitable for high-torque and low-speed applications. Some of them compared PMVMs with the direct-drive permanent magnet synchronous machines (PMSMs), but these studies focused mainly on sub-kW power levels. There is little work in the literature that conducted the comprehensive evaluation of PMVM technology for more specific applications. This article presents the design optimization of a 15-kW surface-mounted PMVM and its comparison with an equivalent conventional PMSM for wind generator applications. It attempts to objectively weigh the relative merits of the two wind generator systems and outline their respective advantages and disadvantages. For validation purposes, an optimally designed 15-kW PMVM was constructed and experimentally evaluated, which is one of the largest PMVM prototypes ever reported in the literature. It shows that the PMVM can be a competitive alternative to the PMSM for this application.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Outer Ferrite-PM-Rotor BLAC Motor Characterization: FEM-Assisted Optimal
           Design and Preliminary Experiments
    • Authors: Andy-Sorin Isfanuti;Lucian Nicolae Tutelea;Ion Boldea;Tiago Staudt;Pyter Ely da Silva;
      Pages: 2580 - 2589
      Abstract: This article is dedicated to design a Ferrite-PM outer rotor-synchronous machine for home appliances. The target requirement is to maximize efficiency at 4500 r/min and 1 kW. A 9 stator teeth/8 rotor poles configuration topology with rotor surface Ferrite PM is chosen for the investigation. To meet this requirement, a novel optimal design procedure employing the Hooke Jeeves algorithm and an analytical model of the BLAC machine is used. The novelty consists in using FEA-based online corrections of the analytical model, embedded in the optimization process to improve accuracy of the analytical model and reduce the computation effort. Further, finite element analysis of the optimization results is presented and compared with experimental results on a built prototype.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Stator Faults Modeling and Diagnostics of Line-Start Permanent Magnet
           Synchronous Motors
    • Authors: D. S. B. Fonseca;Carlos M. C. Santos;Antonio J. Marques Cardoso;
      Pages: 2590 - 2599
      Abstract: In this article, the occurrence of stator faults in line-start permanent magnet synchronous motors is analyzed. A dynamic model of the motor was developed in MATLAB/Simulink, which considers the performance of the motor both in healthy conditions and under the occurrence of interturn short-circuit faults, at an early stage of development. To validate the presented approach, simulation results, covering the full range of operation, and different fault severity levels, are compared with the motor experimental performance. The output of the proposed model, namely voltages and currents, present a good agreement with experimental results, demonstrating the accuracy of the proposed model. Additionally, an online fault diagnostic technique is explored, demonstrating its potentiality.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Design and Analysis of a Hybridly Excited Asymmetric Stator Pole Doubly
           Salient Machine
    • Authors: Wei Xu;Yishu Zhang;Guanghui Du;Mingjie He;Jianguo Zhu;Lei Ning;Caiyong Ye;Wei Hua;
      Pages: 2600 - 2611
      Abstract: This article presents the design and analysis of a 12/7 (numbers of stator/rotor poles) hybridly excited asymmetric stator pole doubly salient machine (HEASPDSM) with a main focus on the special topology and operational principle by using the analytical and 2-D finite element analysis. A full comparison is conducted on the average torque, torque ripples, no-load back electromotive force and flux regulation capacity under the condition of different structural parameters, which can provide good references to the machine design. A 12/7 HEASPDSM is designed and the main performance indexes are analyzed in detail. Based on the parameters, the performance of 12/7 HEASPDSM is compared with traditional 6/7 doubly salient permanent magnet machine (DSPMM) with the same volume and thermal load. Finally, a prototype of the 12/7 HEASPDSM is manufactured and tested to validate the theoretical analysis. The results fully demonstrate that the HEASPDSM possesses the merits of strong flux regulation capability, higher torque density, and wider constant power speed range benefitted from the dc field winding than the traditional DSPMM.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Estimation of PM Machine Efficiency Maps From Limited Data
    • Authors: Solmaz Kahourzade;Amin Mahmoudi;Wen L. Soong;Nesimi Ertugrul;Gianmario Pellegrino;
      Pages: 2612 - 2621
      Abstract: This article investigates the accuracy of the estimation of efficiency maps for permanent magnet (PM) machines using the stator resistance, d- and q-axis flux-linkages versus the corresponding axis current and the iron loss versus the speed characteristic. The ultimate goal is to apply this approach to the experimental measurements, but this article performs initial investigation using only the finite-element (FE) data. Detailed FE data for 50-kW surface PM (SPM) and interior PM (IPM) machines are used to determine the “actual” or exact efficiency map and, hence, the accuracy of using approximations. This article examines the effect on the torque-speed capability curve when ignoring cross-saturation effects. It also examines the modeling of the variation of iron losses as a function of load in the constant torque and power regions. A novel approach based on scaling the no-load (NL) losses as a function of load is proposed and shown to give promising results. FE results from two other machines are also provided, which show good correspondence.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Analysis of Winding MMF and Loss for Axial Flux PMSM With FSCW Layout and
           YASA Topology
    • Authors: Qixu Chen;Deliang Liang;Shaofeng Jia;Qiji Ze;Yibin Liu;
      Pages: 2622 - 2635
      Abstract: This article takes 12-slot/10-pole axial flux permanent magnet (PM) synchronous machine (AFPMSM) with fractional-slot concentrated windings and yokeless and armature (YASA) topology as the research object. Winding magnetomotive force (MMF) of three-phase double-layer layout is analyzed by three kinds of methods, which are star diagram method, winding function method, and holographic spectrum method. The analysis results of finite-element method (FEM) show that the three methods are effective and consistent in analyzing winding MMF. Comparative analysis of iron loss density and B-H magnetizing curves of four typical iron materials are studied. B-H hysteresis loops of silicon steel sheet and soft magnetic composite are measured by magnetizing and measuring equipment to validate iron core per unit mass. The three-dimensional FEM is used for analyzing eddy-current loss in PMs considering radial segmentation. Finally, an AFPMSM prototype is manufactured adopting YASA topology and segmented PM. Load experiments show that solid-liquid coupling computational fluid dynamics model can precisely predict temperature distribution of AFPMSM. Improved cooling jacket is beneficial to afford large current load.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • A Method of Modal Parameter Estimation of the Motor Based on
           Electromagnetic Vibration Exciter
    • Authors: Jianfeng Hong;Shanming Wang;Yuguang Sun;Haixiang Cao;
      Pages: 2636 - 2643
      Abstract: The experimental modal test of the structure of the driving motor has always provided a major contribution to understand and control the vibration phenomena encountered in practice. The hammer test is a common experimental method to obtain a mathematical model of the structure and to validate the theoretical model and finite element method model. However, the hammer or the real vibration exciter will increase the test cost. In this article, an electromagnetic vibration exciter is proposed to achieve the frequency response functions and then the modal parameters can be extracted. Its principle of modal parameters estimation is presented and described in detail. The finite-element analysis and experiments of a 6p/36s permanent magnet motor have been conducted to verify the proposed method.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Stator Winding MMF Analysis for Variable Flux and Variable Magnetization
           Pattern PMSMs
    • Authors: Ryoko Imamura;Robert D. Lorenz;
      Pages: 2644 - 2653
      Abstract: This article analyzes the stator winding magnetomotive force (MMF) in machines to establish a general guideline for active magnetization change techniques used in variable flux permanent magnet synchronous machines and variable magnetization pattern permanent magnet synchronous machines. In this article, the spatial and time harmonics in the stator winding MMF are analyzed to build guidelines for machine topologies and the magnetizing current trajectories for the active magnetization change technique. The proposed guideline about slot pole combinations and magnetizing current pulses are verified through 11 examples from the existing literature, numerical simulation, and experiments.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Simple Commutation Torque Ripple Reduction Using PWM With Compensation
    • Authors: JunHwi Park;Dong-Hee Lee;
      Pages: 2654 - 2662
      Abstract: In this article, a combination of a two- and three-phase switching method to reduce switching loss is presented. In the conduction region, the conventional two-phase switching topology is used to reduce switching loss. On the other hand, in the short commutation region, the proposed modified three-phase switching strategy that incorporates a voltage compensation method is used to reduce torque ripple. The design of the proposed torque compensation method is based on the back electromotive force (EMF). The goal is to optimize the phase current slope by using the phase voltage and back EMF at the start and end point of the commutation region. Assuming that the slope of the back EMF in the commutation region is almost the same as a sinusoidal waveform, a proper pulsewidth modulation duty ratio can be determined to control the current slope. Experiments with a practical brushless dc motor and drive were performed to verify the performance of the proposed method.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • High-Bandwidth Sensorless Control of Synchronous Reluctance Machines in
           the Low- and Zero-Speed Range
    • Authors: Martha Bugsch;Bernhard Piepenbreier;
      Pages: 2663 - 2672
      Abstract: Two aspects of sensorless control of synchronous reluctance machines (SynRMs) in the low-speed and zero-speed range are gaining more and more importance: how to achieve a high control bandwidth and how to lower the test current amplitude to minimize audible noise and high-frequency (HF) losses. A high control bandwidth can be realized by a square-wave-shaped voltage injection (SWSVI). This article presents a new approach, controlling the current ripple generated by the SWSVI constant and simultaneously maintaining a minimum required HF test current amplitude. The proposed solution is optimized for the highly nonlinear machine behavior of SynRMs combined with a standard industrial inverter using regular current sampling. A new low-noise current demodulation by a Kalman filter and its empiric tuning is presented. The prediction step of the filter compensates for the dead time of the control algorithm. Experimental results confirm the excellent performance. Compared to the conventional binomial filter, only half of the test signal amplitude is required. The mean square error of the current demodulation was reduced by 90%.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Self-Sensing via Flux Injection With Rapid Servo Dynamics Including a
           Smooth Transition to Back-EMF Tracking Self-Sensing
    • Authors: Huthaifa M. Flieh;Timothy Slininger;Robert D. Lorenz;Eigo Totoki;
      Pages: 2673 - 2684
      Abstract: Self-sensing control at zero and low speed has been widely implemented and studied by many researchers. This technique is based on injecting a high-frequency voltage or current into the motor to estimate the motor position and speed from the measured motor quantities like current or voltage. Tracking the motor back-EMF or flux signal has been used to control motors during medium- and high-speed operations. This article proposes a high-frequency flux injection (HFFI) based self-sensing using deadbeat-direct torque and flux control to control permanent magnet servo motor at zero and low speed with ideally zero torque ripple, unlike the standard current or voltage injection techniques. The HFFI is combined with a back EMF self-sensing technique to control the motor during medium- and high-speed operations. This article also proposes a method for a smooth transition between these two methods. The proposed controller is used to control different types of slightly salient servo motors during dynamic servo operations.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Deadbeat Direct Flux Vector Control of Surface Permanent Magnet Motor
    • Authors: Sandro Rubino;Iustin Radu Bojoi;Eric Armando;Alberto Tenconi;
      Pages: 2685 - 2699
      Abstract: The predictive control algorithms for electrical drives are currently subject to considerable interest and development. In particular, the predictive torque control is a competitive solution that may replace in the future the conventional control schemes based on linear controllers. Therefore, this article proposes a predictive torque control for surface permanent magnet motor drives requiring a wide constant power range. The predictive algorithm uses a deadbeat direct flux vector control approach for the simultaneous control of the stator flux amplitude and torque-producing current component. The proposed control scheme is suitable for applications requiring a wide speed range with current and voltage constraints. The proposed deadbeat torque controller has been tested on a fractional slot permanent magnet machine and the experimental results demonstrate the full drive controllability, including deep flux-weakening operation with limitation of the load-angle.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • SPMSMs Sensorless Torque Estimation Using High-Frequency Signal Injection
    • Authors: David Reigosa;Ye gu Kang;María Martínez;Daniel Fernández;Juan Manuel Guerrero;Fernando Briz;
      Pages: 2700 - 2708
      Abstract: Torque measurement/estimation in surface permanent magnet synchronous machines (SPMSMs) is needed in many applications. Torque measurement systems are expensive, require extra room, add weight, can introduce resonances into the system, and their performance can be compromised due to electromagnetic interference. Alternatively, torque can be estimated, accurate knowledge of machine parameters being critical in this case. Injection of a high-frequency (HF) signal in the stator via an inverter has been shown to be a viable option for online identification of machine parameters identification required by torque estimation methods for interior PMSMs. However, the reported methods require the use of two pulsating HF currents, which introduces concerns both on the adverse effects on machine's performance (additional noise, vibration, losses, etc.) as well as to the additional computational burden, as HF current controllers are required. This article proposes a torque estimation method for SPMSMs using a single HF signal; furthermore, a HF voltage signal can be used, avoiding the use of HF current controllers, and therefore simplifying the implementation.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Electric Drive Based on an Open-End Winding Surface PM Synchronous Machine
           With a Floating Capacitor Bridge
    • Authors: Albino Amerise;Luca Rovere;Andrea Formentini;Michele Mengoni;Luca Zarri;Pericle Zanchetta;
      Pages: 2709 - 2718
      Abstract: A speed control scheme is presented for a three-phase surface permanent magnet synchronous machine with an open-end stator winding fed by a three-phase inverter and a floating bridge inverter. The latter is used to compensate for the reactive power of the main inverter and to maximize the active power received by the motor, without exceeding the available stator current and dc-link voltage. To reduce the switching losses, the dc-link voltage of the floating inverter bridge varies depending on the operating condition of the motor and the controllability requirements of the system. The experimental results show that a significant improvement in the speed range at constant power is achievable, proportionally to the dc-link voltage of the floating bridge inverter.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Virtual Space Vector-Based Direct Torque Control Schemes for Induction
           Motor Drives
    • Authors: Susmitha Suresh;Rajeevan P. P.;
      Pages: 2719 - 2728
      Abstract: This article presents new direct torque control (DTC) schemes for induction motor (IM) drives based on the concept of virtual voltage space vectors. In the first scheme presented in this article six virtual voltage space vectors alone are used for realizing a DTC with constant switching frequency. The second scheme utilizes both virtual voltage space vectors and the actual voltage space vectors for realizing a twelve-vector DTC for reducing the torque ripple. In the third scheme the number of vectors is increased to 18, by utilizing 12 virtual voltage space vectors and six actual vectors. The fourth scheme extends the concept of virtual vectors to dual inverter fed open end winding IM drives to eliminate the common mode voltage across the windings with increased number of vectors. The virtual voltage space vectors are obtained by switching the adjacent voltage space vectors of a three-phase, two-level inverter at constant switching frequency. Like the conventional DTC scheme these DTC schemes are simple as they are free from co-ordinate transformations and real time computations. These DTC schemes are experimentally verified on an IM fed by two-level voltage source inverters under transient as well as steady state operating conditions. A digital signal processor (TMS320F28335) is used for implementation of the control scheme.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Multiwinding Flyback Clamp Snubber for 10 kV IGCT With Reduced Voltage
           Stress on Clamp Recovery Diodes
    • Authors: Siamak Shirmohammadi;Yongsug Suh;
      Pages: 2729 - 2740
      Abstract: About 10 kV integrated gate-commutated thyristor (IGCT) has the potential to push wind turbine systems to higher power and voltage ratings. Converters employing IGCTs need snubber and overvoltage protection circuit to limit the rate of current rise and peak overvoltage across IGCT during turn on and turn off state, respectively. The conventional resistor-capacitor-diode (RCD) snubber, which is used in such power converters, dissipates a significant amount of power. This article proposes an enhanced scheme of the flyback clamp snubber comprising a flyback transformer with multiwinding secondary wound on a magnetic core. The flyback snubber not only meets all of the IGCTs requirements during on and off-state but also significantly saves power. Unlike the basic concept of flyback clamp snubber, the new scheme has equal voltage stress across the clamp diodes which recover the stored energy of the di/dt snubber into dc-link capacitor. Simulation and experimental results of 10 kV IGCT with conventional RCD and flyback clamp snubbers turn out the benefit of the system.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Resonance Suppression and EMI Reduction of GaN-Based Motor Drive With Sine
           Wave Filter
    • Authors: Ming Yang;Zekai Lyu;Donglin Xu;Jiang Long;Shuyu Shang;Pinhe Wang;Dianguo Xu;
      Pages: 2741 - 2751
      Abstract: Applying high-frequency power devices, such as gallium nitride (GaN) semiconductor devices, to the motor drive can significantly reduce system volume, losses, audible noise, and increase system power density. In this article, an LC filter designed as a sine wave filter is introduced into the servo drive system based on the GaN power device. An undamped method with variable delay time is proposed to solve the electrical resonance issue caused by the LC filter and stator inductor. Detailed stability analysis is conducted, and rules on parameter tuning are provided. With additional proper time delay, the system can be stable without any extra sensors or power losses. Besides, this method is suitable for resonance suppression at a variable switching frequency. Moreover, a wait-free and phase-continuous spread spectrum frequency modulation is applied to solve the issue of electromagnetic interference (EMI). The field-programmable gate array is used to achieve high control bandwidth when implementing the control algorithm. Finally, the ideal sinusoidal drive and low conducted EMI of a permanent magnet synchronous motor is realized. Experiments on a 100 kHz GaN inverter with the LC filter verify the validity of the proposed design and method.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Analytical Model for Reluctance and Cage Rotor Bar Magnetic Gear
    • Authors: Yusuf Akcay;Tom Cox;Alessandro Costabeber;Giacomo Sala;
      Pages: 2752 - 2761
      Abstract: Magnetic gearboxes are becoming more attractive in gearing areas because of their high torque density and high efficiency. In this article, we proposed a 2-D analytical model in a coaxial magnetic gearbox by considering design aspects that can make the design process more reliable, efficient, and cost effective. The proposed analytical model is based on the solution of Laplace's and Poisson's equations for each subdomain, i.e., magnets, airgap, slots, and bars. The global solution is obtained using the boundary and continuity conditions. The analytical model can be used as a design tool for a magnetic gearbox with more design aspects compared with previously proposed methods. The analytical results of field distribution, induced bar current, and electromagnetic torque are obtained and compared with finite-element analysis (FEA).
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Comparison of Three Voltage Saturation Algorithms in Shunt Active Power
           Filters With Selective Harmonic Control
    • Authors: Albino Amerise;Michele Mengoni;Gabriele Rizzoli;Luca Zarri;Angelo Tani;Domenico Casadei;
      Pages: 2762 - 2772
      Abstract: An array of proportional-resonant regulators is often used in shunt active power filters to control the grid currents and reduce the harmonic distortion caused by a distorting load. The voltage that is necessary to compensate for the current harmonics must be consistent with the available dc-link voltage. In this article, three adaptive algorithms for the exploitation of the dc-link voltage are developed and compared. These algorithms adaptively change the voltage saturation of each regulator to preserve the control capability of the fundamental component of the current when the available voltage is not enough to control the filter current. Simultaneously, they try to improve the quality of the grid current because the dc-link voltage of the active power filter is allocated to the regulators to compensate only the most significant harmonics. Some experimental results are shown to demonstrate the feasibility of the three algorithms.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Analysis of a Fourth-Order Step-Down Converter
    • Authors: Shrikant Misal;Mummadi Veerachary;
      Pages: 2773 - 2787
      Abstract: This article proposes a nonisolated wider step-down conversion ratio dc-dc converter having minimum phase behavior at nominal operating condition, for point-of-load applications. Compared to existing quadratic/stacked buck converter variants, the proposed topology shows effective switch utilization at low output voltages, lesser ripple content in source current, and reduced voltage/current stress on components. Time-domain analysis is formulated to anticipate the steady-state converter performance and establish design equations for L-C components. The state-space average model is derived and linearized transfer functions are evaluated to subsequently design a fixed-frequency sliding-mode controller. Step-by-step design procedure is presented to fulfil sliding surface existence, reachability, and stability conditions. Equivalent control law devised in this scheme is duly constituted from source side inductor current dynamics and load voltage error information, so it provides simple realization as well as better transient response. The distinctive features of proposed converter are studied analytically and demonstrated through experimental measurements on a laboratory prototype.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Cascaded Multilevel PV Inverter With Improved Harmonic Performance During
           Power Imbalance Between Power Cells
    • Authors: Abderezak Lashab;Dezso Sera;Frederik Hahn;Luis Camurca;Yacine Terriche;Marco Liserre;Josep M. Guerrero;
      Pages: 2788 - 2798
      Abstract: The difference in power cell irradiances in cascaded multilevel converters results in different duty cycles among those cells when maintaining the maximum power point tracking (MPPT). However, the difference in cell duty cycles is undesired since it is proportional to the output voltage and current distortions. To this regard, a multilevel topology for photovoltaic (PV) applications is proposed, where an H6 bridge power cell is used instead of an H-bridge one. In case of solar irradiance mismatch among the power cells, the proposed converter injects power with lower voltage from the shaded cells without altering the PV voltage; hence maintaining the MPPT operation. This modification allows us to retain an equal duty cycle in all the power cells whatever the meteorological conditions are present; consequently, maintaining good output voltage and current waveform qualities. To test the effectiveness of the proposed solution, a detailed simulation model as well as an experimental prototype is built. The obtained results show that the proposed topology provides significantly improved output voltage and current qualities compared to the cascaded H-bridge one. The performance of the proposed topology compared to one offering improved harmonics performance, according to the European efficiency, has been also compared, where an enhancement of 2.64% has been registered.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Low Voltage Ride-Through Capability of a Novel Grid Connected Inverter
           Suitable for Transformer-Less Solar PV–Grid Interface
    • Authors: Mini Rajeev;Vivek Agarwal;
      Pages: 2799 - 2806
      Abstract: In order to face the challenges due to the large-scale integration of photovoltaic (PV) inverters on the distribution side, the grid-connected PV inverters are expected to provide certain ancillary services. These ancillary services include reactive power support, low voltage ride through (LVRT), and harmonic compensation, just to name a few. In this article, the LVRT capability of a Cuk-derived novel inverter, 6sw-Cuk derived transformerless inverter (6sw-CDTI), suitable for transformer-less grid-PV interface, is explored. The transformer-less inverter, 6sw-CDTI, considered in this work can provide the desired ancillary services more efficiently and at a lesser cost as compared to the conventional inverters. Reactive power support to the grid can be provided without distorting the injected current by 6sw-CDTI with no dc injection due to symmetrical operation in both half cycles. Besides this, the leakage current elimination is not affected because the topological structure is not altered. Experimental results obtained from a 200-W laboratory prototype illustrate how additional control features can be integrated in the inverter control scheme for LVRT. Single-phase instantaneous p-q theory is used for inverter control, and a feed-forward component is added in the control scheme for improved dynamic response.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Multiwinding Transformer Fed CHB Inverter With On-Line Switching Angle
           Calculation Based SHE Technique for Vector Controlled Induction Motor
    • Authors: Piyush Kant;Bhim Singh;
      Pages: 2807 - 2815
      Abstract: A multiwinding transformer for ac-dc converter with multilevel inverter fed induction motor drive (IMD) is presented in this article. An 18 pulse ac-dc conversion is used on input side of the IMD, to meet the power quality requirement as per the IEEE-519 standard. At IM side, a ternary configured nine-level cascaded H-bridge (CHB)-inverter is used to enhance the response of the IMD. A simple online calculation of switching angles and its implementation of selective harmonic elimination strategy, are proposed to control a nine-level CHB-inverter. In this article, a nine-level CHB-inverter is operated at fundamental frequency switching for reducing the losses and suppressing the lower order harmonics (fifth, seventh, and eleventh) to a negligible value and to enhance the torque profile of the IMD. The performances of IMD are evaluated in MATLAB-Simulink environment and then simulated results are verified by test results taken from developed prototype in the laboratory to show its effectiveness for medium power applications.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Switched-LC Based High Gain Converter With Lower Component Count
    • Authors: Avneet Kumar;Yi Wang;Xuewei Pan;M. Raghuram;Santosh Kumar Singh;Xiaogang Xiong;Abhishek K. Tripathi;
      Pages: 2816 - 2827
      Abstract: A compact high step up dc-dc converter with continuous input current and lower device voltage stress is a prime requirement for renewable application. In this article, a high gain dc-dc converter is proposed, which combines the concept of switched inductor and switched capacitor along with a unique interconnection of input-output. This arrangement reduces capacitor voltage stress. The proposed converter has reduced conduction losses, reduced components count, and low voltage stress across the devices. Besides, the proposed converter has lower inductor current ripple, which is suitable for renewable integration. The operation and steady-state analysis of the converter are done in continuous current mode. For the proposed converter, voltage and current stress and the losses are calculated analytically. A comparative analysis is presented to prove the potential of the proposed converter. The dynamic analysis of the proposed converter is performed to regulate the output voltage. Finally, an experimental set up is designed to test the converter under both distinct power ratings and closed loop.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • A Practical On-Board SiC MOSFET Condition Monitoring Technique for Aging
    • Authors: Shi Pu;Fei Yang;Bhanu Teja Vankayalapati;Enes Ugur;Chi Xu;Bilal Akin;
      Pages: 2828 - 2839
      Abstract: In this article, an in situ SiC mosfet degradation monitoring method using readily available converter sensors is presented. Device's drain-source resistance in saturation and ohmic regions are employed as aging precursors to, respectively, indicate die and package-related degradations. The presented findings in this article are essential for low-cost and practical early warning systems in power electronics applications. To verify the effectiveness of the proposed method, a number of power-cycling tests are conducted to analyze aging process and fatigue mechanism. Device static parameters are measured throughout accelerated aging tests and the physical causes behind them are discussed in detail. It is shown that the drain-source resistance within saturation region at low gate bias can be used to indicate die-related degradation. Similarly, at full positive gate bias, device on-state drain-source resistance can be used to detect package-related degradation. In order to find out optimal variables such as applied gate bias, pulse duration, etc., a comprehensive single pulse test is conducted and the results are reported. Finally, the proposed degradation monitoring method is experimentally validated in the context of a three-phase inverter considering different sensor configurations and load types.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Two Novel Open-End Winding Multilevel Unidirectional Six-Phase Rectifiers
           With Reduced Switch Count
    • Authors: Ivan da Silva;Cursino B. Jacobina;Isaac S. de Freitas;Reuben P. R. Sousa;Ayslan C. N. Maia;Nayara B. de Freitas;
      Pages: 2840 - 2851
      Abstract: In this article, two new unidirectional multilevel six-phase power rectifier topologies are proposed and investigated. Such topologies may be applied to ac-dc systems such as wind energy conversions systems, aerospace generator drives, telecommunications or any other application where regenerative operation is either not required or prohibited. The first topology is composed of two three-level neutral-point-clamped (NPC) converters connected to the open-end windings of a six-phase permanent magnet synchronous generator, and a three-phase noncontrolled diode bridge converter. The second topology is composed of three modified NPC converters with the substitution of two controlled switches by diodes in each leg. The use of a noncontrolled converter with diodes aims to reduce the controlled switches count, the system complexity, and the costs. However, it makes both systems nonreversible. The system models, operating principles, the space vector pulsewidth modulation strategies, the dc-links balance, and the control system to ensure the elimination of the zero-crossover distortion caused by the use of the diodes are presented. Due to the high number of levels generated, the systems are suitable for high power applications with voltage and current ratings restrictions. A study concerning harmonic distortion and semiconductor losses for both systems is performed, in order to be compared with a standard configuration. The feasibility of the system is demonstrated by simulation and experimental results.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Small-Signal Disturbance Compensation Control for LCL-Type Grid-Connected
           Converter in Weak Grid
    • Authors: Donghai Zhu;Shiying Zhou;Xudong Zou;Yong Kang;Kaifeng Zou;
      Pages: 2852 - 2861
      Abstract: When the three-phase LCL-type converter is attached to a weak grid, its grid current control will interact with a phase-locked loop (PLL), via the point of common coupling voltage. And, the PLL dynamic has a negative influence on the current control, rendering an undesired performance to grid current control, even leading to the instability issue, if no effective measure is employed. To mitigate this problem, this article proposes a simple and visualized small-signal disturbance compensation control method for the LCL-type grid-connected converter. First, the effect mechanism of PLL dynamic on the current control is analyzed, and the root of the small-signal disturbance caused by PLL dynamic is identified subsequently. Based on this, an improved control method is proposed to compensate the aforesaid PLL-introduced small-signal disturbance terms in current loop, and then, the negative effect of PLL dynamic on the grid current control can be effectively reduced in the weak grid, without modifying the PLL parameters and structure. Moreover, the method is not influenced by the circuit parameters change, and it is robust to the variation of grid impedance. Finally, the proposed method is validated by the experiment.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • FPA Optimized Selective Harmonic Elimination in Symmetric–Asymmetric
           Reduced Switch Cascaded Multilevel Inverter
    • Authors: Kaibalya Prasad Panda;Prabhat Ranjan Bana;Gayadhar Panda;
      Pages: 2862 - 2870
      Abstract: Symmetrical and asymmetrical multilevel inverters (MLIs) have demonstrated its usefulness in a wide range of applications. This is accomplished due to the ongoing improvement by reducing the converter size and enhancement in the voltage quality. In this article, a generalized cascaded MLI structure is developed, which can operate in both symmetric and asymmetric modes. Comparative assessment in terms of the number of components and voltage stress warrants the design superiority. A new selective harmonic elimination (SHE) control using flower pollination algorithm (FPA) is investigated for the developed asymmetrical MLI. The salient features of the FPA such as less burdensome compilation and ability tos single-stage local and global search ascertain the elimination of the targeted harmonics through optimum angles computation. Moreover, the competence of the FPA is verified by comparing it with well-known SHE algorithms. Simulation analysis is carried out in MATLAB/Simulink environment, which validates the workability of the developed system. Experimental tests using fundamental and high switching frequency control techniques are further conducted under a dynamic environment to demonstrate the efficacy of the proposed methodology.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Optimization and Control of a Z-Source, Ultrafast Mechanically Switched,
           High-Efficiency DC Circuit Breaker
    • Authors: Landon Mackey;Md Rifat Kaisar Rachi;Chang Peng;Iqbal Husain;
      Pages: 2871 - 2879
      Abstract: A novel design of the Z-source circuit breaker topology is presented to minimize on-state losses of the protection device. An ultrafast mechanical switch is proposed to commutate the fault current and improve the controllability of the circuit breaker. Replacing the power thyristor in the Z-source circuit breaker and integrating an advanced control scheme reduces energy losses with a low-resistance mechanical contactor. The proposed design facilitates bidirectional current flow, enhances control capability for distributed energy resources, and improves ride-through capabilities during load transients. Z-source circuit breakers utilize an impedance network to create a forced current zero crossing in the event of a fault, allowing the inline thyristor to isolate the fault from the source through reverse bias. However, full load current flows through the thyristor, resulting in high loss and heat generation. The concept is validated, and a proper control scheme is developed for this circuit breaker through an analytical estimation model of the system dynamics during a fault. Simulation and modeling are performed in power systems computer aided design (PSCAD) and piecewise linear electrical circuit simulation (PLECS). Finally, an experimental laboratory prototype is tested to validate the analytical and simulation models and certify the control logic.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Comparison and Discussion on Shortcircuit Protections for Silicon-Carbide
           MOSFET Modules: Desaturation Versus Rogowski Switch-Current Sensor
    • Authors: Slavko Mocevic;Jun Wang;Rolando Burgos;Dushan Boroyevich;Marko Jaksic;Constantin Stancu;Brian Peaslee;
      Pages: 2880 - 2893
      Abstract: Survivability of silicon-carbide (SiC) mosfet modules during short circuit (SC) is essential for modern power electronics systems due to large economic implications. SiC mosfet modules exhibit narrow SC withstand times and generally much lower SC robustness than silicon (Si) insulated-gate bipolar transistors (IGBTs). This puts a critical concern on their utilization, further stressing the importance of reliable protection. This article presents a comprehensive analysis and discussion on the SiC mosfet module SC protection and performance comparison between conventional desaturation detection, previously used for Si IGBT protection, and Rogowski switch-current sensor (RSCS) detection. In addition, this article presents the experimental design for soft turn-off as a reaction to the SC detection to avoid excessive overshoots during the abrupt turn-off of the SC current. To perform different types of SC with various fault inductances on different temperatures, and for the sake of fair comparison under the same conditions, a gate-driver unit for 1.2 kV SiC mosfet half-bridge modules is developed containing both detection methods. The results demonstrate that both methods are successful in protecting the module in all SC types, with superiority of the RSCS detection and concerns for desaturation detection in high-inductance and high dc-bus voltage SC events.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Semiconductor Temperature and Condition Monitoring Using
           Gate-Driver-Integrated Inverter Output Voltage Measurement
    • Authors: Michael Schubert;Rik W. De Doncker;
      Pages: 2894 - 2902
      Abstract: Bond-wire liftoff caused by mechanical stress due to thermal cycling is one of the major failures in power electronic systems. Condition monitoring concepts which allow prediction of these failures are often based on voltage-drop detection and thermal monitoring. However, solutions to determine the junction temperature and semiconductor voltage drop during operation often require additional effort and lead to increased cost. In this article, a direct semiconductor temperature detection method is proposed which is based on instantaneous semiconductor voltage-drop monitoring. A mosfet inverter system, equipped with a digital integration-based instantaneous output voltage measuring circuit, is extended by software to enable instantaneous semiconductor voltage-drop detection. Experimental results demonstrate that the proposed method is feasible for online temperature measurement and detection of increased resistance due to bond-wire faults. The voltage measurement resolution is sufficient for dynamic temperature monitoring, including fundamental frequency temperature cycles at very low frequency.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • The Design and Analysis of Large Solar PV Farm Configurations With
           DC-Connected Battery Systems
    • Authors: Oluwaseun M. Akeyo;Vandana Rallabandi;Nicholas Jewell;Dan M. Ionel;
      Pages: 2903 - 2912
      Abstract: Typically, solar inverters curtail or “clip” the available power from the photovoltaic (PV) system when it exceeds the maximum ac capacity. This article discusses a battery system connected to the dc link of an inverter to recuperate this PV energy. Contrary to conventional approaches, which employ two dc-dc converters, one each for the battery and solar PV system, the proposed configuration utilizes a single dc-dc converter capable of simultaneously operating as a charge controller and a maximum power point tracking (MPPT) device. In addition to improving the overall system capacity factor, increasing the conversion efficiencies, and ensuring MPPT stability, the proposed configuration offers a simple solution for adding energy storage to existing PV installations. With this configuration, the excess power that will otherwise be curtailed due to inverter rating limitations is stored in the battery and supplied to the grid during periods of reduced irradiance. Moreover, a systematic methodology for sizing a dc-bus connected battery to minimize total PV energy curtailed was developed using an annual PV generation profile at the Louisville Gas and Electric and Kentucky Utilities E. W. Brown solar facility at Kentucky. The detailed behavior of the proposed system and its power electronics controls and operations were validated with case studies developed in PSCAD/EMTDC software for variable power generation and PV output power smoothing.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • SyRG-PV-BES-Based Standalone Microgrid Using Approximate Multipliers Based
           Adaptive Control Algorithm
    • Authors: Rohini Sharma;Seema Kewat;Bhim Singh;
      Pages: 2913 - 2924
      Abstract: This article deals with the adaptive control algorithm to maximize the distributed generations (DGs) in islanded microgrid. The approximate multiplier least mean square (AMLMS) control scheme is used for the extraction of fundamental load component with reduced steady state error and faster convergence to provide better performance than conventional LMS control. This control focuses on reduction of complexity of LMS by adding multipliers in the finite impulse response filter and updating the coefficients. The AMLMS control algorithm for a voltage source converter is also effective in compensating harmonics for power quality improvement of islanded microgrid system while feeding nonlinear load. In an islanded microgrid at ac side, a synchronous reluctance generator based pico-hydropower generator is used because it is economical than other conventional generators. At dc side, a photovoltaic array and a bidirectional dc-dc converter (BDC) are used. The BDC with a storage battery maintains the optimal power flow to provide the power equilibrium between load and sources through dc-link voltage regulation. The BDC also mitigates the second order harmonic from the battery charging and discharging current. Test and simulation results validate the effectiveness of AMLMS control under steady and dynamic conditions of solar insolation change and load unbalance.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • A Novel Control Scheme for Wind Turbine Driven DFIG Interfaced to Utility
    • Authors: Sambasivaiah Puchalapalli;Bhim Singh;
      Pages: 2925 - 2937
      Abstract: This article deals with a phase-locked loop (PLL)-based novel control for wind turbine driven doubly fed induction generator interfaced to utility grid with a battery energy storage (BES) connected at the dc link. The control of grid-side converter (GSC) is modified to export/import constant power to/from the grid. The state of charge of BES helps in deciding the reference export power to the grid apart from the manual selection using averaged wind power in a particular period of time. An off maximum power point tracking logic is incorporated in the rotor-side converter (RSC) control to operate the BES within its constraints and, moreover, to feed constant power to the grid. In addition, the energy management scheme of the system is presented in the form of flowchart for both exporting and importing power to/from the grid. The RSC and GSC have taken care of unity power factor operation at stator terminals and to mitigate harmonics and grid currents balancing, respectively. The system performance is found robust as the PLL response is not affected even under grid voltages with dc offset. The system is modeled and simulations are carried out in MATLAB using SimPowerSystems tool box. Moreover, the control scheme performance is compared with conventional control algorithms both in terms of PLL and converter controls. To validate the effectiveness of the control scheme, a prototype of the system is developed. Test results demonstrate the satisfactory performance of the system under various operating conditions.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Converter-Level Reliability of Wind Turbine With Low Sample Rate Mission
    • Authors: Dao Zhou;Frede Blaabjerg;
      Pages: 2938 - 2944
      Abstract: The thermal dynamics of power semiconductors and power capacitors are closely related to the reliability and affect the cost of power electronic converter. However, the component loading in a wind turbine system is disturbed by many factors of the power converter, which presents various time constants from microseconds to hours. To determine the system availability in such system is a challenge and need detailed analysis. In the case of a mission profile with 1-hour sample rate, a simplified circuit model, loss model, and thermal model of the active power switches and passive capacitors are needed and described. According to the long-term electrothermal profile, the percentile lifetime of a single component can be predicted. The Weibull function based time-to-failure distribution can then be used to link from component-level to converter-level reliability. From analysis of a 2 MW wind turbine system, it can be seen that the dc-link capacitor bank dominates the converter-level reliability.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Vehicle-to-Home Usage Scenarios for Self-Consumption Improvement of a
           Residential Prosumer With Photovoltaic Roof
    • Authors: Francesco Giordano;Alessandro Ciocia;Paolo Di Leo;Andrea Mazza;Filippo Spertino;Alberto Tenconi;Silvio Vaschetto;
      Pages: 2945 - 2956
      Abstract: This article proposes a procedure for the control of electric vehicle (EV) batteries, aiming to have an optimal matching between local renewable production, domestic loads, and EV consumption. The procedure starts with the analysis of historical photovoltaic (PV), EV, and domestic load profiles. Load and PV profiles are forecasted using statistical-based algorithms, while the expected patterns of EV usages are forecasted using a combination of statistics and clustering techniques. Then, the forecasted profiles are used to estimate future energy balances trough an optimization process. Finally, the real-time management corrects the forecasting logic and checks the parameters of the EV storage to guarantee its correct and safe operation. Three different EV usage profiles (obtained by the clustering of 215 real users) are shown and their impact on the energy balance of EV-PV-home systems is quantified. The results are finally compared with those obtained with a traditional rule-based logic working without forecasts, by also reporting a detailed analysis of the main aspects having an impact on the results.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Solar PV-BES Based Microgrid System With Multifunctional VSC
    • Authors: Vivek Narayanan;Seema Kewat;Bhim Singh;
      Pages: 2957 - 2967
      Abstract: A solar photovoltaic (PV)-battery energy storage-based microgrid with a multifunctional voltage source converter (VSC) is presented in this article. The maximum power extraction from a PV array, reactive power compensation, harmonics mitigation, balancing of grid currents and seamless transition from grid connected (GC) mode to standalone (SA) mode and vice versa, are performed in this system. Whenever the grid fails, this system operates in SA mode automatically, thereby without causing any interruption in supplying the load. Similarly, it automatically shifts to the GC mode, when the grid is restored. The VSC functions in current control for GC mode, and it operates in voltage control for SA mode of operation. This system is capable of extracting the maximum power from the solar PV array irrespective it is operating in the GC mode or SA mode. The charging and discharging of the battery are controlled by using a bidirectional dc-dc converter. It regulates the dc-link voltage to the maximum power point voltage of the PV array. If the absence of the battery is detected, then the control is automatically shifted to VSC for performing the extraction of the maximum power of the PV array.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • DoS-Resilient Distributed Optimal Scheduling in a Fog Supporting
           IIoT-Based Smart Microgrid
    • Authors: Seyede Zahra Tajalli;Mohammad Mardaneh;Elaheh Taherian-Fard;Afshin Izadian;Abdollah Kavousi-Fard;Morteza Dabbaghjamanesh;Taher Niknam;
      Pages: 2968 - 2977
      Abstract: Industrial Internet of Things (IIoT) is an architecture that facilitates the feasibility of the distributed control of the modernized industrial systems mainly through the Internet of Things and cloud computing. This article proposes an optimal scheduling framework for the real-time operation of smart microgrids in the IIoT environment using an average consensus-based algorithm. The introduced framework suggests a fog layer as a complementary layer of IIoT to reduce latency and provide local computation and data storage for the proposed industry. Security of the system against probable attacks is the other concern that should be observed. To this end, this article sets out to evaluate the impact of a particular type of attack called the denial of service on the performance of the proposed method. Accuracy, feasibility, and fast response of the scheme are demonstrated through simulation results on a microgrid test system in the presence of dispatchable and nondispatchable generation units with heterogeneous devices.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Self-Adjustable Step-Based Control Algorithm for Grid-Interactive
           Multifunctional Single-Phase PV-Battery System Under Abnormal Grid
    • Authors: Shailendra Kumar;Laxmi Narayan Patel;Bhim Singh;A. L. Vyas;
      Pages: 2978 - 2987
      Abstract: This article deals with the single-phase grid interactive multifunctional solar PV (photovoltaic) system with seamless power transfer capability. This multifunctional PV-battery system is also helpful to enhance the quality of power in the utility grid. The system provides an uninterrupted power to nonlinear loads during the nonavailability of utility and renewable energy resource. This PV-battery system comprises two stages. First stage is a PV array-boost converter along with a battery energy storage-bidirectional converter that is integrated at dc-link and another is voltage source converter (VSC), which performs the task of harmonics elimination and injection of harvested energy to the utility along with nonactive power compensation. In standalone mode, the shape of load voltage is sustained sinusoidal by islanded technique. A proportional integral controller is used to sustain the dc-link voltage to a specific value. In order to improve the dynamic response of the PV-battery system, a feedforward control for solar PV participation is used. A self-adjustable step-based control is introduced for the VSC in this work. This estimates the real power reflecting portion of the load current in order to show the features of the PV-battery system. Simulation studies are carried out in MATLAB Simulink. The experimental performance of the developed PV-battery system is found satisfactory even under abnormal grid condition.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • PHIL Experimentation on Fault Ride Through Behavior of Doubly Fed
           Induction Generator-Based Wind System in the Presence of Fault Current
    • Authors: Mirle Vishwanath Gururaj;Narayana Prasad Padhy;
      Pages: 2988 - 3005
      Abstract: In the literature, the fault ride through (FRT) studies of the doubly fed induction generator (DFIG)-based wind system consider fault to occur after the fault current limiter (FCL) with respect to the DFIG system. In this article, the fault is considered before FCL and the power hardware in the loop (PHIL) experimentation is performed. Results demonstrate that the occurrence of the fault before FCL can worsen the FRT of the DFIG system. To address this, a novel arrangement of FCL with four power electronic switches in a particular fashion has been suggested. This arrangement allows the perception of fault occurring before FCL as after FCL due to the alternate path of power flow thereby improving the FRT of the DFIG. Furthermore, a quick fault detection and switching technique has been developed which is able to detect the fault by comparing the instantaneous value of the phase current with the threshold. Thereby, it is possible to achieve on/off of the switches upon the fault occurrence with negligible time delay. In order to validate the effectiveness of the proposed technique, the PHIL experimentation is performed at sub/supersynchronous mode of operations (±0.1 slip), different fault resistances (6, 20 Ω), delay time (40 ms), and various fault perception instants (negative, zero, positive). The results justify the effectiveness of the proposed arrangement in improving FRT of the DFIG when a fault occurs before the FCL with respect to the DFIG in comparison to the existing literature and in the absence of FCL in the system.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • A Dual-Channel-Enhanced Power Generation Architecture With Back-to-Back
           Converter for MEA Application
    • Authors: Xiaoyu Lang;Tao Yang;Chen Li;Hossein Balaghi Enalou;Serhiy Bozhko;Patrick Wheeler;
      Pages: 3006 - 3019
      Abstract: This article proposes an improved power generation architecture (PGA) for future more electric aircraft applications. In the proposed architecture, a starter/generator is connected to the high-pressure (HP) shaft, and a generator is connected to the low-pressure (LP) shaft. Their outputs supply a common dc bus via active power converters. A back-to-back (B2B) converter is deployed to link the ac terminals of the two generators. The proposed topology embraces three main advantages. First, with the B2B converter, the HP generator can operate at a high speed without flux weakening; thus, the magnitude of stator current will be decreased when output same active power. This will lead to the reduction of power losses on the generators and the active rectifiers. Second, the proposed PGA allows power transfer from the LP and to the HP shafts. This can potentially reduce the fuel consumption and increase aircraft engine compressor surge margins when the engine is at low-speed setting. Third, the B2B converter provides an additional power flow path to the generators under converter fault scenarios, hence improving the postfault operation ability. For the proposed PGA, engine benefits, modeling, control design, and efficiency improvements are illustrated in detail. The control performances of the proposed PGA, engine performance improvement by transferring power from the LP to HP shaft, and power loss reduction are verified via simulations and experimental results collected from a twin-shaft aircraft power generation test rig.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Acceleration, Drive Cycle Efficiency, and Cost Tradeoffs for Scaled
           Electric Vehicle Drive System
    • Authors: Emma Arfa Grunditz;Torbjörn Thiringer;Nima Saadat;
      Pages: 3020 - 3033
      Abstract: This article investigates and quantifies, for varying drive system ratings (0.5-2.0 times the rating of a small and large reference system), the tradeoff relations between the electric vehicle acceleration performance and energy consumption during a wide range of drive cycles, using detailed load-dependent loss models. Additionally, the results are related to estimated drive system cost by transparently determined scalable electric motor and inverter cost models. When reducing the system rating to half, the cost is 83% of the small reference system and 76% of the large. The acceleration time (0-100 km/h) decreases nonlinearly with increasing system rating. Interestingly, the drive cycle energy consumption generally decreases with decreasing drive system rating, and most cycles show a minimum consumption with a downscaled drive system. For the small system, the strongest impact was noted for the HWFET cycle where the energy consumption is reduced 2% when downscaling the drive system by 0.5 relative to the reference system. For the large system, NYCC shows the largest reduction in energy consumption: 4% when scaled by 1.6 relative to the reference system.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Analysis and Design of Inductive and Capacitive Hybrid Wireless Power
           Transfer System for Railway Application
    • Authors: Bo Luo;Tao Long;Limou Guo;Ruimin Dai;Ruikun Mai;Zhengyou He;
      Pages: 3034 - 3042
      Abstract: Inductive power transfer (IPT) and capacitive power transfer (CPT) are mainly two effective ways to achieve wireless power transfer (WPT). IPT system needs capacitor to compensate the system, while the CPT system requires inductor to tune the system. Therefore, IPT coupler can be used to compensate the CPT coupler and vice versa. In this article, an inductive and capacitive hybrid wireless power transfer (HWPT) system is proposed to improve the system coupler antimisalignment ability. The couplers of IPT and CPT are employed together to compensate each other and transfer power together. Superposition theory is used to analyze the system working principle in detail. With the analysis results, a scaled-down system is built to validate the performance of the proposed approach. Experimental results show that the proposed HWPT system can achieve 653 W output power with 87.7% dc-dc efficiency at the well-aligned condition, and the maximum variation of the output power is 8.3% with the coupler misalignment from 0 to 270 mm (halfwidth of the coupler), which agree well with the analysis results.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • An Adaptive Sensorless Measurement Technique for Internal Temperature of
           Li-Ion Batteries Using Impedance Phase Spectroscopy
    • Authors: Ala A. Hussein;Abbas A. Fardoun;
      Pages: 3043 - 3051
      Abstract: This article proposes an adaptive sensorless measurement technique for internal temperature of lithium-ion (Li-ion) batteries. The proposed technique is based on measuring the impedance phase of the battery in real time by a simple search algorithm. The proposed technique then identifies the zero-crossing frequency at which the phase of the impedance is zero. From the value of the zero-crossing frequency, the cell's internal temperature is estimated. Details on the proposed technique followed by the experimental verification using a 3.8-V/2600-mAh Samsung Li-ion battery cell at temperatures between -20 °C and +50 °C are presented.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Performance of a Two-Stage EHD Gas Pump in a Circular Pipe Operating at
           Uneven Applied Voltages
    • Authors: Yilma T. Birhane;Sheam-Chyun Lin;Feng C. Lai;
      Pages: 3052 - 3060
      Abstract: The performance of a two-stage electrohydrodynamic (EHD) gas pump in a circular tube has been investigated for operating conditions in which each stage is charged at a different voltage. The main objective of the study is to examine the characteristics of resulting flow as well as the efficient use of energy in sustaining and improving the volume flow rate produced by a single-stage pump over a greater distance. To this end, two different sizes of the tube are employed (61.8 and 127.8 mm in diameter). Each stage uses eight emitting electrodes flush mounted on the tube wall. In addition, two electrode configurations, aligned and offset, with fixed electrode spacing have been considered. The electrodes at both stages are charged at voltages in positive polarity from 18 to 22 kV. The velocity profile and volume flow rate delivered are compared with those produced by the same pump operating at even voltages to provide additional insight into the problem. The results, thus, obtained have important implications for practical use of the EHD gas pump.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Triboelectric Charging of Granular Polymers Previously Exposed to
           Dielectric Barrier Discharges in Atmospheric Air
    • Authors: Ahlem Benabderrahmane;Thami Zeghloul;Karim Medles;Amar Tilmatine;Lucian Dascalescu;
      Pages: 3061 - 3067
      Abstract: The aim of the present article is to study the feasibility of continuous dielectric barrier discharge (DBD) treatment of granular plastic materials in view of improving their triboelectric charging ability, and assessing the effectiveness of associating plasma treatment with the triboelectrostatic separation process. The effects of the following DBD parameters were studied: the amplitude and the frequency of the applied high voltage, the thickness of the dielectric barrier, the distance between the electrodes of the reactor as well as the speed of the conveyor that was used for the transfer of the granular materials though the nonthermal plasma zone. The study was carried out on millimeter-sized polyethylene particles. It was found that the charge of DBD-treated particles increases with the applied high voltage and decreases with the speed of the conveyor. Both the distance between the electrodes and the thickness of the dielectric barrier have a remarkable effect on the charge acquired after DBD treatment. Within the experimental domain of this study, the frequency of the high voltage does not significantly affect the efficiency of the tribocharging process. Under optimal operating conditions given by the first series of experiments, two distinct triboelectrical series were established, one for treated particles and the other for untreated particles, using eight types of granular plastics [acrylonitrile butadiene styrene, polyethylene (PE), polypropylene, polyvinyl chloride, crystalline polycarbonate, polystyrene (PS), high impact polystyrene, and crystalline polystyrene], Finally, an electrostatic separation experiment was carried out on a plasma-treated PE-PS mixture using a roll type electrostatic separator. The results were then compared with those obtained for an untreated mixture. It was found that plasma treatment improved by about 40% the purity and recovery of the sorted products.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Multiobjective Framework for Optimal Integration of Solar Energy Source in
           Three-Phase Unbalanced Distribution Network
    • Authors: Sriparna Roy Ghatak;Surajit Sannigrahi;Parimal Acharjee;
      Pages: 3068 - 3078
      Abstract: Recently, there is a global consent regarding the high penetration of solar energy (SE) resources to mitigate technical and environmental concerns. SE is intermittent in nature and if its incorporation is not properly planned, a multitude of serious technical issues will arise in the network. In this perspective, considering the energy industry's practical aspects, a comprehensive robust practical planning model is presented in this article to optimally integrate intermittent SE source with battery and DSTATCOM to maximize reliability and financial, environmental, and technical benefit of the system. Voltage unbalance in the system creates varieties of problems, such as poor power quality, higher power loss, and lesser system efficiency. However, owing to the lack of proper industrial real data, researchers were unable to judge and incorporate the voltage unbalance issues, which are significant for the planning engineers to provide efficient solutions. Keeping this into view, the proposed method is tested on the real three-phase unbalanced 240-node network of the USA where the customers are equipped with smart meters to provide real power data for realistic analysis. K-means clustering algorithm is utilized to generate the appropriate number of scenarios that can accurately include the intermittency of solar power generation and load. A multiobjective algorithm, namely the extended version of NSGA II (E_NSGA II), is utilized for the optimal allocation of the devices. Compare to other algorithms, results reveal the competence and robustness of the proposed planning methodology for the optimal allocation of SE with battery storage and DSTATCOM in order to maximize the overall benefits of the three-phase network.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Control of Grid Fed PV Generation Using Infinite Impulse Response Peak
           Filter in Distribution Network
    • Authors: Bhim Singh;Pavitra Shukl;
      Pages: 3079 - 3089
      Abstract: An upsurge in the integration of renewable sources to the utility grid has resulted into escalating concerns regarding power quality (PQ) improvement. In order to provide efficient operation under weak grid conditions, the necessity of a competent control technique is dominant. Consequently, the implementation of an infinite impulse response (IIR) peak filter is used here for harmonics mitigation, power factor correction, and alleviating other PQ issues by providing distribution static compensator (DSTATCOM) capabilities. In addition, this control technique also works during conditions when solar photovoltaic (PV) power is not procurable. During day, the requirement of load is fed from the solar PV array and the stored grid power. On the other hand, at night when the power from solar PV array is unavailable, the requirements of load are fulfilled from the grid and DSTATCOM operation ensures power quality improvement. In order to validate this system, it is maintained according to the IEEE-519 standard. The considered weak grid conditions include load unbalancing, intermittent solar insolation, voltage sag, voltage swell, voltage distortion, and voltage unbalance conditions. The benefits of IIR peak filter include adaptive computation during filtering, thereby alleviating the computational complexity. Moreover, less memory space is required during execution guaranteeing fast performance during weak grid conditions. Simulated results are utilized to depict the behavior of the system during abnormal grid conditions. Moreover, its comparative performance with the existing control techniques, is also presented. For further substantiation and in order to observe reliable operation, a laboratory prototype is developed and tested during weak grid conditions such as voltage distortion, voltage unbalance, voltage sag, voltage swell, and load unbalancing.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • A Novel Energy Storage-Based Net-Load Smoothing and Shifting Architecture
           for High Amount of Photovoltaics Integrated Power Distribution System
    • Authors: Shyamal Patel;Muhammad Ahmed;Sukumar Kamalasadan;
      Pages: 3090 - 3099
      Abstract: This article presents a novel ramp rate control and active power smoothing and shifting methodology for net-load profiles in large power distribution networks where high amount of photovoltaic (PV) penetration levels exist. The novelty is that the proposed methodology uses dynamic state-of-charge (SoC) management, energy storage optimal use of any given size and fast-Fourier transform-based reference curves that adequately fit energy storage system (ESS) active and reactive power capabilities. Then, a least square minimization-based optimization method is applied taking both ancillary applications into consideration and to maintain SoC within limits based on ESS capacity. The methodology is applied on a 8500 nodes US power grid model using CYMEDist simulation platform and applied on a real US power distribution system. Results show significant level of net-load ramp rate reduction as well as smoothing of fast fluctuations (up to 60%) due to both PV intermittency and load changes. The approach is also capable of breaking large systems into virtual local net-load locations where ESS's are installed to mitigate the severity of the anticipated shape of system net-loads.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Design of Experiments Predictive Models as a Tool for Lifespan Prediction
    • Authors: Mateusz Szczepanski;David Malec;Pascal Maussion;Philippe Manfé;
      Pages: 3100 - 3113
      Abstract: Since the development of power electronic components, which allowed the manufacturing of reliable and efficient inverters, variable speed drives using inductive motors have become more and more popular. The pulsewidth modulation (PWM) technique has proven to be a very effective method of rotational speed control. However, the fast-changing voltage pulses, with very steep slopes (in the order of a few kilovolt/microsecond), have brought new hazards for the electrical insulation system of such motors. Very high frequency harmonic components of PWM voltage will result in significant overvoltage due to an impedance mismatch between the cable and the motor. As an effect, the voltage seen by some parts of the insulation system may exceed the partial discharge inception voltage stating the localized partial discharges activity. The aim of this article is to investigate and analyze the aging process of the enameled wire exposed to different factors and to propose a method allowing them to predict their lifespans in given conditions. This study introduces a prediction based on the design of experiments method and the statistical Weibull distribution. Thanks to the model obtained with short multistress aging tests, it is possible to predict the results of significantly longer ones. Moreover, the adopted methodology is proposed that allows us to predict the scatter of the long tests based on the short-time results dispersion. The same approach is used to compare different products between each other and rank them. All model predictions are compared with the experimental data in order to prove the model accuracy.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Modulated Model Predictive Control for Four-Leg Inverters With Online Duty
           Ratio Optimization
    • Authors: Dan Xiao;Kazi Saiful Alam;Md. Parvez Akter;S. M. Showybul Islam Shakib;Daming Zhang;Muhammed Fazlur Rahman;
      Pages: 3114 - 3124
      Abstract: Conventional finite control set (FCS) predictive load-voltage control for four-leg inverters features simplification in digital implementation compared to its complex counterpart, three-dimensional space vector modulation. However, the FCS approach is typically characterized by a variable switching frequency, low steady-state performance, and a higher average switching frequency in the neutral leg than the other three legs. To overcome these shortcomings, an online duty-cycle-optimization based model predictive control technique is proposed in this article. The performance of the inverter is evaluated experimentally in terms of load voltage tracking in different operating conditions such as nonlinear loads and balanced/unbalanced references. The proposed technique fulfills the requirement of a high-performance converter, constant switching frequency, and enhanced load voltage tracking at a lower sampling rate and, thus, solves the drawbacks of the conventional FCS model predictive control for a four-leg inverter. Furthermore, the proposed approach can facilitate the overmodulation operation, which is desirable for this type of power converters under nonlinear and unbalanced loading conditions.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Event-Driven Distributed Active and Reactive Power Dispatch for
           CCVSI-Based Distributed Generators in AC Microgrids
    • Authors: Jingang Lai;Xiaoqing Lu;Antonello Monti;Rik W. De Doncker;
      Pages: 3125 - 3136
      Abstract: This article presents a novel distributed event-driven control strategy that will dispatch and share the active and reactive power outputs of massive current-controlled voltage source inverter (CCVSI)-based distributed generators (DGs) in an ac microgird. The proposed distributed power sharing control strategy is fully distributed and only driven at their own event time, which effectively reduces the frequency of controller updates compared with continuous-time feedback control. Moreover, each CCVSI-based DG only requires the local voltage and current measurement from its own and some nearest neighbors (but not all) for the distributed power sharing control at the last event-driven time by using low-bandwidth communication links and then, updates the control inputs to restore the active and reactive powers to desired values for further reducing the consumption of computing and communication resources to some extent. The Lyapunov technique is employed to derive the stability and convergence analysis of the proposed dynamic event-driven conditions. The effectiveness of the proposed control strategy is verified under various scenarios by a modified IEEE 34-bus test network in MATLAB/SimPowerSystems.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Performance and Analysis of a New Brushless Synchronous Generator for DC
           Microgrid Application
    • Authors: Saptarshi Basak;Amit Kumar Mondal;Chandan Chakraborty;
      Pages: 3137 - 3148
      Abstract: DC grid is gaining popularity as different renewable energy sources and energy storage elements used to form the microgrid are dc in nature. Moreover, HVdc systems have been found to be advantageous for off-shore wind farms. For such systems located in remote places, maintenance becomes a key issue, which makes the use of brushless generator preferable. Very recently, a new synchronous generator with embedded brushless synchronous exciter has been reported. This work explores the performance of such generators for dc microgrid application. A simple diode rectifier is used to interface the generator to the dc grid. Such uncontrolled rectifier will cause current quality issues. A passive tuned filter can help in mitigating this issue and also assist in improving the voltage regulation by providing reactive power support. A method to select the right filter parameters has been proposed. Simulation results obtained from MATLAB/Simulink and experimental results from a fabricated laboratory prototype have been presented. Both simulation and experimental results reveal the effectiveness of the proposed system.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Loss of Utility Detection and Seamless Operation of Distributed Generation
    • Authors: Parusharamulu Buduma;Smitha Joyce Pinto;Gayadhar Panda;
      Pages: 3149 - 3158
      Abstract: In this article, a protection method for photovoltaic distributed generation (DG) system to fend off from islanding condition caused by the loss of the utility grid has been proposed along with a control scheme. The proposed islanding protection scheme is developed with a parametric time-frequency analysis technique for detection and an optimal probabilistic neural network for classification of events. Along with the islanding protection, a nested loop robust control scheme has been proposed for the seamless operation of the DG system during different uncertainty scenarios. The proposed system with islanding protection and robust control scheme has been implemented in MATLAB/SIMULINK environment. The practical feasibility of the proposed method is verified with an experimental setup and dSPACE control kit. For demonstrating the superiority of the proposed islanding protection method and robust control scheme for the DG system, a discussion of the results is presented.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • An Observer-Based Switch Open-Circuit Fault Diagnosis of DC–DC Converter
           for Fuel Cell Application
    • Authors: Shengrong Zhuo;Arnaud Gaillard;Liangcai Xu;Chen Liu;Damien Paire;Fei Gao;
      Pages: 3159 - 3167
      Abstract: The power semiconductor device is one of the most fragile components of the dc-dc power converters in industrial applications. In this article, a Luenberger observer-based switch fault diagnosis method is proposed for the dc-dc interleaved boost converter for fuel cell (FC) application. The inductor current within the main controller system is selected as the diagnosis variable, avoiding the use of extra sensors. Moreover, an adaptive threshold is introduced to deal with the effects of the converter circuit parameter uncertainty, and the converter operation point variation resulted from FC nonlinear volt-ampere characteristic. The proposed fast fault diagnosis method shows good robustness to false alarms. The simulation and experiment results demonstrate the robustness and validity of the proposed method.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Design and Real-Time Implementation of a Centralized Microgrid Control
           System With Rule-Based Dispatch and Seamless Transition Function
    • Authors: Chu Sun;Geza Joos;Syed Qaseem Ali;Jean Nicolas Paquin;Carlos Mauricio Rangel;Fares Al Jajeh;Ilja Novickij;Francois Bouffard;
      Pages: 3168 - 3177
      Abstract: With reference to the newly released microgrid standards, design and real-time implementation of a centralized microgrid control system is presented in this article. In the grid-connected mode, the utility grid will provide the voltage and frequency reference at the point of connection. The assets within the microgrid will follow power command references provided by the control system. In the islanded mode, the energy storage system (ESS) can provide the voltage and frequency reference to all other generators. Based on the state-of-charge of the ESS, a rule-based dispatch is proposed, with priority given to diesel generator and then the storage in the middle state of charge range. To alleviate power fluctuations, meet smooth planned islanding requirement, and compensate for the feeder losses ignored in dispatch algorithm, a supplementary slack-bus power control based on closed-loop feedback and first-order filter is proposed. The potential of the storage system in firming short-time power fluctuation and providing long-term load shifting capabilities is exploited. An emergency dispatch function for unplanned islanding considering the speed of response limitation of a diesel generator is also proposed. The proposed control strategy is implemented and tested on a controller hardware-in-the-loop test bench. It demonstrates the capability of the control system to reduce load shedding and renewable curtailment, and to implement power management at the point of interconnection.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Grid Integration of Small-Scale Photovoltaic Systems in Secondary
           Distribution Network—A Review
    • Authors: Ramanuja Panigrahi;Santanu K. Mishra;Suresh C. Srivastava;Anurag K. Srivastava;Noel N. Schulz;
      Pages: 3178 - 3195
      Abstract: The relative share of renewable energy, specifically the solar photovoltaic (PV), is increasing exponentially in the world electric energy sector. This is a cumulative result of reduction in the cost of solar panels, improvement in the panel efficiency, and advancement in the associated power electronics. Among different types of PV plants, installation of small-scale rooftop PV is growing rapidly due to direct end-user benefits and lucrative governmental incentives. There are various standards developed in regards to grid integration of PVs and other distributed generations (DGs). Different power converter topologies are developed to interface the PV panel with the utility grid. To keep up with the stringent regulations imposed by the standards, various control strategies and grid synchronization methods have been developed. This review article amalgamates and summarizes all of the aforementioned aspects of a grid-integrated PV system including various standards, power stage architectures, grid synchronization methods, operation under extreme events, and control methodologies, pertaining to small-scale PV plants. This article will help freshman researchers to gain some familiarity with the topic and introduce them to some of the key issues encountered in this field.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Testing the Performance of Battery Energy Storage in a Wind Energy
           Conversion System
    • Authors: Adnan Sattar;Ahmed Al-Durra;Cedric Caruana;Mahdi Debouza;S. M. Muyeen;
      Pages: 3196 - 3206
      Abstract: This article examines the dynamic and transient performances of a battery energy storage system (BESS) connected with the output of a wind energy conversion system to smoothen the short-term fluctuations in the output power. A low-power experimental real-time testbed, using battery storage and representative power converters, is interfaced with a real-time digital simulator for the reduced-scale power hardware-in-the-loop simulation. Different configurations, where the energy storage system is integrated on the ac side via static synchronous compensator and directly at the dc link of the frequency converter using back-to-back converters, are examined under both constant and variable references. For each case, the resulting error in the net power flow, the operation of the battery, and the conduction losses in the power conversion stage are examined. The performances using the constant and variable reference of the storage device with full and reduced-order hardware stage of a storage element are demonstrated. The low-voltage transient performance of the BESS is also tested and the results are presented. The novel approach of the real-time low-power BESS testbed opens the door for in-lab testing of the energy storage devices for large wind or solar photovoltaic farms to save time and money.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Multiagent-Based Energy Trading Platform for Energy Storage Systems in
           Distribution Systems With Interconnected Microgrids
    • Authors: H. S. V. S. Kumar Nunna;Anudeep Sesetti;Akshay Kumar Rathore;Suryanarayana Doolla;
      Pages: 3207 - 3217
      Abstract: In this article, an agent-based transactive energy (TE) trading platform to integrate energy storage systems (ESSs) into the microgrids' energy management system is proposed. Using this platform, two different types of energy storage market models are proposed to promote local-level (within the microgrid) and communal- or global-level ESSs' participation in the intra- and intermicrogrid TE markets. Also, a reinforcement learning algorithm known as simulated-annealing-based Q-learning is used to develop bidding strategies for ESSs to participate in the TE markets. Besides energy trading, the proposed system also accounts for the losses caused by energy transactions between ESSs and microgrids using a complex current-tracing-based loss allocation method. The overall efficacy of the proposed energy market management system is demonstrated using a modified IEEE 123-bus distribution system with multiple microgrids and ESSs. Based on simulation results, it is observed that the proposed model can effectively reinforce the balance between the supply and the demand in the microgrids using the mix of local and global ESSs.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Forensic Analysis of Fire in a Substation of a Commercial Center
    • Authors: Guido Ala;Salvatore Favuzza;Massimo Mitolo;Rossano Musca;Gaetano Zizzo;
      Pages: 3218 - 3223
      Abstract: In this article, the authors discuss the legal liabilities of the professional engineer as both the engineer of record of a project and the construction site manager. In particular, this article analyzes the case of a fire at the end-user medium voltage-low-voltage (MV-LV) substation of a shopping center in Italy, which occurred a few years after the maintenance works on the electrical installation. The professional engineer who had designed and overseen the construction of the substation was accused of professional negligence. The authors through the examination of applicable technical standards, as well as of safety regulations, demonstrate that the professional engineer had acted diligently and that there was no ground for the negligence charges. The analysis of the substation fire is provided, and the importance of the chain of custody, the chronological documentation, and the secure storing of all the artifacts and fire-damaged evidence is discussed. The authors believe that this article can be a useful reference for electrical forensics engineers, investigating similar accidents.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Evaluating the Incident Energy of Arcs in Photovoltaic DC Systems:
           Comparison Between Calculated and Experimental Data
    • Authors: William R. Sekulic;Peter McNutt;
      Pages: 3224 - 3230
      Abstract: Incident energies in photovoltaic (PV) systems are modeled using a variety of methods. These methods are referenced in NFPA 70E and other publications. Direct-current (dc) systems, such as PV systems, may not follow the conventional model used in the present standards. Using experimental data, we will correlate and refine the incident-energy calculations for PV systems. This article proposes a methodology for validating the latest 70E methods for dc PV systems. A forthcoming article will present more of the test results after we improve the test setup and procedures. This article will only discuss dc arcs in PV systems and will not cover arcs in other types of dc systems (e.g., batteries, capacitors, etc.).
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • An Assessment of Immersion Cooling for Power Electronics: An Oil Volume
           Case Study
    • Authors: Igor Amariz Pires;Rafael Átila Silva;Iago Tourinho Oliveira Pereira;Osvane Abreu Faria;Thales Alexandre Carvalho Maia;Braz de Jesus Cardoso Filho;
      Pages: 3231 - 3237
      Abstract: Power electronics demand appropriate heat dissipation to secure life span, reliability, and power density. Among several cooling methods, oil immersion is an efficient and cost effective one. Natural convection is the most reliable considering the lack of pumps and fans compared to other practical ways of immersion cooling. This article brings a case study of a power electronics device submerged in an oil tank, the same one used for power transformers. Using computational fluid dynamics simulations and an experimental setup, the natural convection process is demonstrated as well as the better heat flow dissipation of oil immersion cooling.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Enhancement of Power Quality in an Actual Hot Rolling Mill Plant Through a
    • Authors: Gonzalo Arturo Alonso Orcajo;Josué Rodríguez Diez;José M. Cano;Joaquín G. Norniella;Joaquín Francisco Pedrayes González;Carlos H. Rojas;Pablo Ardura G;Diego Cifrián R;
      Pages: 3238 - 3249
      Abstract: A strategic use of a static synchronous compensator (STATCOM) for providing dynamic reactive power management of a hot rolling mill plant along with active mitigation of harmonics is considered in this article. More specifically, the behavior of a cascaded H-bridge (CHB) converter-based STATCOM is assessed. The impact of the steel to be milled and the specific features of the plant on the design of the STATCOM is discussed. The proposed strategy is analyzed from the point of view of reactive power flow management, active power loss reduction, and voltage control at the coupling point, as well as harmonics reduction and decrease of unscheduled shutdowns in the event of a trip in the passive filtering system. The article is based on real plant measurements, simulation tests, and results from an experimental platform built at scale, and represents the first stage of an ambitious plan to renew this type of plants aimed at transforming them into active elements for electrical energy management.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Deep-Learning-Based Harmonics and Interharmonics Predetection Designed for
           Compensating Significantly Time-Varying EAF Currents
    • Authors: Ebrahim Balouji;Karl Bäckström;Tomas McKelvey;Özgül Salor;
      Pages: 3250 - 3260
      Abstract: In this article, a new approach to compensate both the response and reaction times of active power filters (APF) for special cases of highly time-varying harmonics and interharmonics of electric arc furnace (EAF) currents is proposed. Instead of using the classical approach of taking a window of past current samples and analyzing the data, future samples of EAF currents are predetected using a deep learning (DL)-based method and then analyzed, which provides the opportunity to make real-time analysis. This can also serve the needs of other possible APF applications. Two different methods for prediction of future samples of harmonics and interharmonics have been proposed: predetection of harmonics and interharmonics in the time domain (TD) and in the frequency domain (FD). To obtain the best possible accuracy for both methods, grid search has been employed for parameter optimization of the DL structure. Both TD and FD approaches have been tested on field data, which had been obtained from transformer substations supplying EAF plants. It is shown that the response time of the APF algorithms can be compensated using the TD-based approach, while it is possible to compensate both the response and reaction times of APFs using the proposed FD-based approach. The developed method can be considered to be a feasible candidate solution for generating reference signals for the controllers of new generation of compensation devices, which can be referred to as predictive APFs.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • High-Speed Temperature Monitoring for Steel Strips Using Infrared Line
    • Authors: Rubén Usamentiaga;Daniel F. Garcia;Jesús M. Pérez;
      Pages: 3261 - 3271
      Abstract: Infrared thermography is nowadays used in a wide range of applications. In the steel industry, infrared thermography is mostly used for temperature measurement, which is required for process and quality control. In this article, a high-speed temperature monitoring system for steel strips is proposed. The proposed system is based on infrared line scanners, which are the most suitable devices for temperature monitoring of moving objects. Accurate temperature measurement is critical for this type of application. Therefore, a rigorous methodology to apply quantitative thermography is presented. In addition, this work proposes accurate temperature and spatial calibrations, including a geometrical model, calibration targets, and an optimization procedure. The proposed calibrations open up the possibility of detecting regions of interest in the resulting thermograms, determining the position with accuracy while avoiding distortions. The proposed system is applied to a real industrial application: temperature monitoring in cold rolling. Tests show excellent performance, producing accurate results that provide detailed information about the temperature of very long steel strips.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
  • Concepts for Development of Autonomous Coal Mine Shuttle Cars
    • Authors: Vasilis Androulakis;Joseph Sottile;Steven Schafrik;Zach Agioutantis;
      Pages: 3272 - 3280
      Abstract: During the last few decades, the mining industry has increasingly turned to autonomous systems in its efforts to modernize and advance mining methods and techniques. Vehicle automation in such complex working environments can play a critical role in improving worker safety and mine productivity. Moreover, as the global demand for minerals continues to increase, such technologies will enable access to deeper and more difficult to mine orebodies. The research reported in this article seeks to demonstrate the feasibility of autonomous batch haulage vehicles in the underground coal mining production cycle. By introducing autonomous shuttle cars, the operator can be removed from dusty, noisy, and potentially dangerous conditions and be placed in a relatively safe location, while supervising the machine rather than operating it. This article presents an overview of the approach taken, a description of a lab-scale model and mock mine environment, and preliminary results for autonomous navigation of the prototype shuttle car.
      PubDate: May-June 2020
      Issue No: Vol. 56, No. 3 (2020)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762

Your IP address:
Home (Search)
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-