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  Subjects -> ELECTRONICS (Total: 187 journals)
Showing 1 - 200 of 277 Journals sorted alphabetically
Acta Electronica Malaysia     Open Access  
Advances in Electrical and Electronic Engineering     Open Access   (Followers: 7)
Advances in Electronics     Open Access   (Followers: 90)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Power Electronics     Open Access   (Followers: 38)
Advancing Microelectronics     Hybrid Journal  
Aerospace and Electronic Systems, IEEE Transactions on     Hybrid Journal   (Followers: 334)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 26)
Annals of Telecommunications     Hybrid Journal   (Followers: 9)
APSIPA Transactions on Signal and Information Processing     Open Access   (Followers: 9)
Archives of Electrical Engineering     Open Access   (Followers: 14)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 30)
Bioelectronics in Medicine     Hybrid Journal  
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 20)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 38)
Biomedical Instrumentation & Technology     Hybrid Journal   (Followers: 6)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 13)
BULLETIN of National Technical University of Ukraine. Series RADIOTECHNIQUE. RADIOAPPARATUS BUILDING     Open Access   (Followers: 1)
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: 293)
ECTI Transactions on Computer and Information Technology (ECTI-CIT)     Open Access  
ECTI Transactions on Electrical Engineering, Electronics, and Communications     Open Access  
Edu Elektrika Journal     Open Access   (Followers: 1)
Electrica     Open Access  
Electronic Design     Partially Free   (Followers: 117)
Electronic Markets     Hybrid Journal   (Followers: 7)
Electronic Materials Letters     Hybrid Journal   (Followers: 4)
Electronics     Open Access   (Followers: 97)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 10)
Electronics For You     Partially Free   (Followers: 100)
Electronics Letters     Hybrid Journal   (Followers: 26)
Elkha : Jurnal Teknik Elektro     Open Access  
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 55)
Energy Harvesting and Systems     Hybrid Journal   (Followers: 4)
Energy Storage Materials     Full-text available via subscription   (Followers: 3)
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: 10)
Frequenz     Hybrid Journal   (Followers: 1)
Frontiers of Optoelectronics     Hybrid Journal   (Followers: 1)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 205)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IACR Transactions on Symmetric Cryptology     Open Access  
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 99)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 80)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 49)
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 Power Electronics Magazine     Full-text available via subscription   (Followers: 72)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 71)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 58)
IEEE Transactions on Circuits and Systems for Video Technology     Hybrid Journal   (Followers: 26)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 42)
IEEE Transactions on Electron Devices     Hybrid Journal   (Followers: 19)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 26)
IEEE Transactions on Power Electronics     Hybrid Journal   (Followers: 78)
IEEE Transactions on Signal and Information Processing over Networks     Full-text available via subscription   (Followers: 12)
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  
IET Microwaves, Antennas & Propagation     Hybrid Journal   (Followers: 35)
IET Nanodielectrics     Open Access  
IET Power Electronics     Hybrid Journal   (Followers: 55)
IET Smart Grid     Open Access  
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 Electronics, IEEE Transactions on     Hybrid Journal   (Followers: 70)
Industrial Technology Research Journal Phranakhon Rajabhat University     Open Access  
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 35)
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: 13)
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: 11)
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: 6)
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: 3)
Journal of Advanced Dielectrics     Open Access   (Followers: 1)
Journal of Artificial Intelligence     Open Access   (Followers: 11)
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: 32)
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 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: 3)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 173)
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  
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: 29)
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: 26)
Journal of Signal and Information Processing     Open Access   (Followers: 9)
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  
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Magnetics Letters, IEEE     Hybrid Journal   (Followers: 7)
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: 27)
Nanotechnology Magazine, IEEE     Full-text available via subscription   (Followers: 41)
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: 9)
Optical Communications and Networking, IEEE/OSA Journal of     Full-text available via subscription   (Followers: 15)
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)
Pulse     Full-text available via subscription   (Followers: 5)
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: 9)
Research & Reviews : Journal of Embedded System & Applications     Full-text available via subscription   (Followers: 5)
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: 56)
Semiconductors and Semimetals     Full-text available via subscription   (Followers: 1)
Sensing and Imaging : An International Journal     Hybrid Journal   (Followers: 2)
Services Computing, IEEE Transactions on     Hybrid Journal   (Followers: 4)
Software Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 78)
Solid State Electronics Letters     Open Access  
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 13)
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)
Universal Journal of Electrical and Electronic Engineering     Open Access   (Followers: 6)
Ural Radio Engineering Journal     Open Access  
Visión Electrónica : algo más que un estado sólido     Open Access   (Followers: 1)
Wireless and Mobile Technologies     Open Access   (Followers: 6)
Wireless Power Transfer     Full-text available via subscription   (Followers: 4)
Women in Engineering Magazine, IEEE     Full-text available via subscription   (Followers: 11)
Електротехніка і Електромеханіка     Open Access  

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Similar Journals
Journal Cover
Industry Applications, IEEE Transactions on
Journal Prestige (SJR): 1.02
Citation Impact (citeScore): 4
Number of Followers: 35  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0093-9994
Published by IEEE Homepage  [191 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: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • 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: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Information for Authors
    • Abstract: These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Feasibility Study of Sustainable Energy Sources in a Fossil Fuel Rich
           Country
    • Authors: Abdullah A. Almehizia;Hussein M. K. Al-Masri;Mehrdad Ehsani;
      Pages: 4433 - 4440
      Abstract: This paper represents an approach for renewable energy sources integration with the existing grid. Unique types of loads can be exploited to allow for a sustainable solution to energy integration. A case study of Saudi Arabia is investigated where desalination plants coupled with a water storage tank is utilized to mitigate the variability of renewable sources. A hybrid photovoltaic-wind turbine generator system is proposed. The results indicate two critical points. First, even in a fossil fuel rich country, sustainable renewable sources are economically feasible. The second point is that the typical storage element (i.e., batteries), is not always the best candidate for energy storage as in the case of desalination plants. Instead, storing the excess energy as water in a storage tank is economical and less prone to failures as compared to large-scale batteries. The problem is formulated as an optimization problem and solved using heuristic techniques.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Business Model Incorporating Harmonic Control as a Value-Added Service
           for Utility-Owned Electricity Retailers
    • Authors: Kangping Li;Qitian Mu;Fei Wang;Yajing Gao;Gang Li;Miadreza Shafie-Khah;João P. S. Catalão;Yongchun Yang;Jiafeng Ren;
      Pages: 4441 - 4450
      Abstract: With the deepening of electricity market reform in China, the competition in the electricity retail market becomes increasingly intense. Electricity retailers (ERs) need to explore new business models to enhance their competitiveness in the retail market. Meanwhile, with the improvement of industrial production and people's living standards, more and more nonlinear electrical equipment have been put into use, leading to severe harmonic pollution problems. Harmonic pollution causes loss of electricity, resulting in the economic loss of customers, especially for large industrial customers. In the above contexts, this paper proposes a novel business model that incorporates harmonic control as a value-added service into electricity retail contracts for utility-owned ERs. Both utility-owned ERs and customers can benefit from the designed business model. For customers, it helps them to improve the power quality while saving the electricity cost. For ERs, it helps them to cultivate the customer loyalty and improve the customer satisfaction. A case study is performed to demonstrate the effectiveness of the proposed business model.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Multistage Dynamic Equivalent Modeling of a Wind Farm for the Smart Grid
           Development
    • Authors: Yuhao Zhou;Long Zhao;Ting-Yen Hsieh;Wei-Jen Lee;
      Pages: 4451 - 4461
      Abstract: With high penetration level of wind generation, it is critical to establish a robust dynamic equivalent model (DEM) of the wind farm for system's stability analysis and smart grid development. Since wind farms may have a multistage development and are installed with different wind turbines from different technologies and/or venders, in this paper, a wind farm model with different types of wind generators (WGs) is constructed according to Western Electricity Coordinating Council generic WG models. In order to describe the dynamic behavior of the wind farm during system disturbances, by applying the data from phasor measurement units, a multistage hierarchical parameter identification process based on heuristic algorithms is proposed to develop a DEM for the wind farm. Different scenarios are simulated to validate the effectiveness and robustness of the proposed equivalent model. In addition, the modal analysis is performed to further validate the proposed approach by comparing the eigenvalues between the detailed wind farm model and the equivalent model.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Compressive System Identification for Multiple Line Outage Detection in
           Smart Grids
    • Authors: Mohammad Babakmehr;Farnaz Harirchi;Ahmed Al-Durra;S. M. Muyeen;Marcelo Godoy Simões;
      Pages: 4462 - 4473
      Abstract: Real-time power line outage detection (POD) and localization is an important monitoring task for the modern smart grid. Reliable monitoring of power lines status plays a critical role in the system-wide blackout prevention. In this paper, the main aim is to address the multiple POD problems by exploiting the compressive system identification—a time-efficient approach in a complex network analysis. A typical power network is considered as a single graph, and the mathematical formulation of the POD problem is initialized using the dc power-flow model and graph theory concepts. Next, a sparse representation-based formulation for this problem (POD-SRP) is reported and further improved and generalized in case of multiple large-scale outages. Practical and technical challenges associated with this sparse recovery problem are partially addressed by developing new SRP solvers. Furthermore, a new sparse-based mathematical formulation for POD is introduced and termed as “Binary-POD-SRP,” which specifically deals with two particular issues, namely, the high coherence and the signal dynamic outrange. Finally, the identification performance of the proposed framework is evaluated by a variety of case studies, which are modeled using IEEE standard test-beds. We specifically discuss how the inherent challenges within large-scale multiple-outages can be solved by applying these new techniques and formulations.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Exploring New and Conventional Starting Methods of Large Medium-Voltage
           Induction Motors on Limited kVA Sources
    • Authors: Aaron H. VanderMeulen;Thomas J. Natali;Thomas J. Dionise;Gianni Paradiso;Kevin Ameele;
      Pages: 4474 - 4482
      Abstract: Liquefied natural gas peak shaving facilities utilize large horsepower motors to drive refrigeration compressors needed for the liquefaction process. Utilities impose strict voltage dip requirements making an evaluation of various motor starting methods imperative. The large motor starting studies must be evaluated while also factoring in equipment and controls complexity and overall project capital costs. This case study will evaluate several motor starting methods, comparing technical performance and cost considerations, identifying the best method for the project requirements and reviewing the field measurements during operation confirming acceptable performance of the installed method.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Electrical Safety Analysis in the Presence of Resonant Grounding Neutral
    • Authors: Massimo Mitolo;Rossano Musca;Michele Tartaglia;Gaetano Zizzo;
      Pages: 4483 - 4489
      Abstract: The resonant grounding is one of the possible methods of the system neutral grounding for the medium voltage distribution. IEEE standards do define this grounding configuration, but important advantages and drawbacks of the resonant grounding might not be fully known, due to its rather uncommon application in North America. On the other hand, resonant grounding in Europe is imposed by the increased requirements for power quality, especially for medium-voltage (MV) industrial users, imposed to electric utilities by regulatory authorities, with the purpose to protect the interests of users and consumers. Level of the continuity of the service, magnitude and phase of ground-fault currents, magnitude of touch voltages, all depend on how the neutral is connected to ground. In this paper, the authors will discuss electrical safety features of the resonant ground, and analyze issues when a substation, originally operated with different methods of system neutral grounding, is reconfigured with a resonant ground. In particular, a conservative approach for preserving safety during high-voltage (HV)-MV substations’ reconfiguration is herein proposed; the cases of the substation reconfiguration from resonant grounding to isolated-from-ground and vice versa shall be analyzed. Finally, the analysis of the impact of the use of Petersen coil on the global grounding systems will be provided.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Grounding the DC Microgrid
    • Authors: Jafar Mohammadi;Firouz Badrkhani Ajaei;Gary Stevens;
      Pages: 4490 - 4499
      Abstract: A comprehensive knowledge of the available grounding strategies and their effects is essential for design, operation, and protection of the dc microgrid. This paper investigates and compares different dc microgrid grounding strategies that involve the choice of grounding configurations and grounding devices. The impacts of different grounding strategies on line-to-ground (LG) fault detection and protection, transient LG fault current magnitude, leakage current level, common mode voltage, personnel/equipment safety, system reliability, service continuity, and insulation requirements are thoroughly investigated. LG fault response of a low-voltage dc microgrid with different grounding devices is studied by detailed simulation of a realistic study system modeled in the PSCAD software. The study results indicate that: 1) the ungrounded, bipolar solidly grounded, unipolar parallel resistance grounded, and bipolar resistance grounded dc microgrids enable LG fault ride through, due to the low fault current; 2) the unipolar solidly grounded, bipolar solidly grounded, diode-grounded, and thyristor-grounded dc microgrids experience significantly large transient discharge currents under LG faults; and 3) the unipolar solidly grounded, diode-grounded, thyristor-grounded, and unipolar low-resistance-grounded dc microgrids provide considerable steady-state LG fault current which necessitates fast detection and clearance of faults.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Heat Generation and Failure in Padmount Transformers Due to Zero Sequence
           Saturation
    • Authors: J. Curtiss Fox;Ramtin Hadidi;Nancy LaFlair;Jesse Leonard;Joseph Hodges;
      Pages: 4500 - 4506
      Abstract: After a transformer failed following a double-phase fault, there was an interest in understanding how the fault mechanism led to the failure. This paper investigates this fault condition in detail and demonstrates the underlying challenges in correcting the failure. The electrical and thermal system models were developed and simulated to analyze the transformer response under double-phase fault conditions. Experimental measurements validated the simulation results on a real three-phase distribution transformer. This paper presents the results from simulated and experimental analysis from double-phase fault on a Yg–Yg distribution transformer.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Simple Approach to Conductor Sizing and Prolonging the Thermal Life of
           
    • Authors: Brandon R. Meier;Badrul Chowdhury;
      Pages: 4507 - 4514
      Abstract: Electrical conductors are, arguably, the most important component of industrial and commercial electrical distribution systems as electrical conductors, or just conductors, facilitate the interconnections between a source (e.g., generator, renewable energy source, utility, electrical distribution panel, etc.) and load (e.g., wall outlet, control panel, motor, etc.). However, for typical electrical system installations, electrical conductors are rarely given the attention deserved. In general, the selection of the conductors becomes a fine balancing act of meeting the minimum National Electric Code (NFPA 70) requirements for minimum ampacity and the economics of choosing aluminum versus copper. This can lead to conditions where conductors are not adequately sized for the conditions they are exposed to, which can result in premature failure of cable insulation. This paper presents a simple approach to proper conductor selection, with an emphasis on maximizing the thermal life of cable insulation.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A New Protection Scheme for MMC-Based MVdc Distribution Systems With
           Complete Converter Fault Current Handling Capability
    • Authors: Xing Huang;Li Qi;Jiuping Pan;
      Pages: 4515 - 4523
      Abstract: DC fault handling is a critical aspect for designing and operating dc distribution systems. DC distribution protection must be rapid to avoid the damages caused by the fast growth of dc fault currents. For medium-voltage dc (MVdc) distribution systems, low-cost high-speed dc breakers are still challenging. A hybrid modular multilevel converter (MMC)-based dc fault protection and restoration method is proposed for a cost-effective dc fault protection solution for MMC-based MVdc systems. In the proposed protection solution, the converter topology and associated fault handling can bypass and interrupt the fault currents from both ac and dc sources, and thus allowing fast dc fault isolation by low-cost no-load dc disconnectors. Furthermore, the proposed dc protection solution facilitates converter fault ride-through and system restoration after fault removal. Simulation results of the pole-to-pole fault protection show the satisfactory performance of the proposed protection solution and scheme.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Solid-State Transformers for Distribution Systems–Part I:
           Technology and Construction
    • Authors: Saleh A. M. Saleh;Chistian Richard;Xavier Francis St. Onge;Katie M. McDonald;Emre Ozkop;Liuchen Chang;Basim Alsayid;
      Pages: 4524 - 4535
      Abstract: Solid-state transformers (SSTs) are an emerging technology that has been developed to improve the stability, reliability, and economic operation of distribution systems. These new transformers are composed of a medium ac voltage (MV) stage, a dc stage, and a low ac voltage (LV) stage. Passive and active dc links are used to construct the dc stage in SSTs in order to offer new functionalities, including hybrid (ac and dc) distribution, reactive power compensation, voltage/frequency regulation, power quality improvement, and distributed generation utilization. On one hand, a distribution SST has its ac stage connected to an MV level, which mandates specific power electronic converter (PEC) topologies, switching element capabilities, and filtering circuits. On the other hand, the dc-link stage has to provide isolation between the MV and LV levels, which requires the employment of isolated dc PECs. Part I of this work provides a review of SST designs and constructions (for deployment in distribution systems), in terms of the required technology, supported functionalities, and construction features.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • The State-of-the-Art Methods for Digital Detection and Identification of
           Arcing Current Faults
    • Authors: Saleh A. Saleh;Marcelo E. Valdes;Claudio Sergio Mardegan;Basim Alsayid;
      Pages: 4536 - 4550
      Abstract: This paper reviews approaches used to detect and identify arcing currents, including arcing current faults. The reviewed approaches are categorized as the time-domain, frequency-domain, and time–frequency approaches. The time-domain approach extracts shoulders (zero values of the current around zero crossing points), spikes and jumps, abnormal magnitudes (lower or higher than normal), and high rate of change of the current. The frequency-domain approach extracts the high-frequency components, harmonic components, sub-harmonic components, and cross-correlation indicator. The time–frequency approach extracts high-frequency sub-bands that contain non-stationary frequency components, which may have non-stationary phases. The three approaches are implemented to test their accuracy, computational requirements, and sensitivity to system parameters. These tests are performed by processing of currents that are collected for normal and dynamic conditions, conventional faults, and currents with high or low arcing components. Test results provide a performance comparison for the tested approaches.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Measures to Minimize Series Faults in Electrical Cords and Extension Cords
    • Authors: Giuseppe Parise;Erling Hesla;Claudio S. Mardegan;Luigi Parise;Elisabetta Bragagni Capaccini;
      Pages: 4551 - 4556
      Abstract: In electrical power systems, cords and extension cords are exposed to mechanical damage and other insulation stresses. Mechanical damage to stranded conductors can reduce locally their cross section or break them and cause anomalous local conditions of overheating or arcing. The ordinary protective devices cannot detect the series faults that persist, so the fault point remains energized and is subject to electric shock and fire hazards. Effective protection can be accomplished by implementing active and passive measures: installing arc-fault circuit interrupters or arc-fault detection devices, able to detect arcing faults, or wiring the circuits with a grounding protection conductor to involve the ground in every fault. In this way, residual current protective devices (residual current devices or ground fault protective devices) quickly protect the series faults not only with arc, but also without it. Ground-fault-forced cables facilitate by design the conversion of any kind of cable fault to a ground fault. They are particularly recommended for cords and extension cords, internal circuits to grounded equipment, uninterruptible power system continuity circuits, aircraft circuits, road tunnels, data centers, refrigerated containers parks, residences, and hospitals.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Review on Magnetic Gears: Topologies, Computational Models, and Design
           Aspects
    • Authors: Yawei Wang;Mattia Filippini;Nicola Bianchi;Piergiorgio Alotto;
      Pages: 4557 - 4566
      Abstract: Geared devices are commonly used to match the operating speed and torque of the power source with the second mover. Such geared devices are usually mechanical gears. As counterparts of the conventional mechanical gears, magnetic gears (MGs) are becoming promising devices, mainly due to the merits of physical isolation between moving parts, no gear lubrication, no mechanical fatigue, inherent overload protection and reduced maintenance, etc. Recently, several new topologies have been proposed to achieve better performances. In this paper, a general review of MGs is presented, including a discussion of the most common and upcoming topologies and a description of the working principle. A comparison of different topologies is carried out in terms of gear ratio and torque density. The main computational techniques generally adopted for coaxial MGs are listed and described. Some key aspects concerning the design, the existed challenges, and potential applications are also discussed. This paper aims to provide a comprehensive overview of the MG for readers working in this field.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Influence of Clamping Bolts on Electromagnetic Performance of PMSM
           Machines and Its Restraining Methods
    • Authors: Jiabei Zhu;Lijian Wu;Xiaoyan Huang;Youtong Fang;
      Pages: 4567 - 4577
      Abstract: The clamping bolts and bolt-holes can be employed to stack the steel laminations in permanent magnet machines. Their influence on the electromagnetic performance is analyzed in this paper, including the electromagnetic torque, open-circuit torque, phase back-EMFs, and circulating current loss. A restraining method of dummy bolt-hole is proposed to achieve both balanced phase back-EMFs and zero circulating currents in bolts. The ratio of bolt-hole edge thickness to bolt-hole radius is optimized to compensate the reduction of stator yoke caused by bolt-holes. Besides, a method of open bolt-hole edge is proposed to restrain the circulating currents. Furthermore, structure analyses are conducted to prove the reliability of the electromagnetic design. The proposed method is verified by experiments on a prototype machine.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Thermal Performances of Induction Motors for Applications in Washdown
           Environment
    • Authors: Eric Giacomo Armando;Aldo Boglietti;Enrico Carpaneto;Alessandro Castagnini;Marco Seita;
      Pages: 4578 - 4584
      Abstract: Some specific application fields of electric motors, such as food and beverage applications, require highly demanding hygiene procedures that involve a highly aggressive environment for the motor, including frequent high pressure and high temperature washing with water or more aggressive detergents. Specific materials and protection features are used in motors to better withstand such environment; however, these have an impact on performance and lead to oversized machines. This paper describes some solutions and their impact on performance, with specific focus on the thermal properties of the analyzed machine.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Detection of Nonadjacent Rotor Faults in Induction Motors via Spectral
           Subtraction and Autocorrelation of Stray Flux Signals
    • Authors: Miguel Enrique Iglesias-Martínez;Pedro Fernández de Córdoba;Jose A. Antonino-Daviu;J. Alberto Conejero;
      Pages: 4585 - 4594
      Abstract: In this paper, statistical signal processing techniques are applied to electromotive force signals captured in external coil sensors for adjacent and nonadjacent broken bars detection in induction motors. An algorithm based on spectral subtraction analysis is applied for broken bar identification, independent of the relative position of the bar breakages. Moreover, power spectrum analyses enable the discrimination between healthy and faulty conditions. The results obtained with experimental data prove that the proposed approach provides good results for fault detectability. Moreover, the identification of the faults, and the signal correlation indicator to prove the results are also presented for different positions of the flux sensor.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Design and Analysis of a Flux-Concentrated Linear Vernier Hybrid Machine
           With Consequent Poles
    • Authors: Ahmed A. Almoraya;Nick J. Baker;Kristopher J. Smith;Mohammad A. H. Raihan;
      Pages: 4595 - 4604
      Abstract: In low-speed applications, variable-reluctance permanent magnet machines are often proposed due to their efficient use of magnet material and high torque density. This becomes even more important in large linear applications, where the translator is longer than the stator. Often, however, very low power factors are experienced by this class of machines. This paper proposes a V-shaped flux concentrated version of a consequent pole linear Vernier hybrid permanent magnet machine and compares it to a surface-mounted magnet variant. Using finite-element analysis validated by two laboratory prototypes, it is shown that the flux-concentrated version increases the airgap flux density, which potentially leads to an improvement in the force density and efficiency or can be used to increase the operating power factor.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Analysis and Reduction of Electromagnetic Vibration of PM Brush DC Motors
    • Authors: Shanming Wang;Jianfeng Hong;Yuguang Sun;Haixiang Cao;
      Pages: 4605 - 4612
      Abstract: This paper focuses on the electromagnetic vibration and its reduction in PM brush dc motors. First, the air gap flux density distribution and the radial force density distribution are derived in detail, and compared with the results of the finite element method. Next, two types of vibration sources, called pulsating force and bending moment, are analyzed. Then, two passive improvement methods, called varied PM pole width in axial direction and copper ring, are proposed to reduce the magnetic forces and their vibration, and their principles of the vibration reduction are described in detail. For further explanation, a rotor-skewed motor is used for comparison, and the radial force on the motor is discussed and the influence of four different thicknesses of copper ring on the motor vibration is analyzed. Finally, three 2p/24s sample motors are manufactured and the experimental vibration results confirm the analysis and the proposed improvement technique.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Modeling and Experimental Verification of High-Frequency Inductive
           Brushless Exciter for Electrically Excited Synchronous Machines
    • Authors: Junfei Tang;Yujing Liu;Nimananda Sharma;
      Pages: 4613 - 4623
      Abstract: Electrically excited synchronous machines have shown potential to be an alternative to permanent magnet synchronous machines in electromobility and wind power applications. High-frequency wireless power transferring technology enables a compact design of brushless exciters for the machine. In this paper, a dynamic model of high-frequency brushless exciters is proposed for the purposes of operating condition monitoring and excitation control. The modeling is done by using arithmetic and differential equations as well as considering different operation modes of the system. The operation modes are defined based on the physical behaviors of the excitation circuit. Experiments are performed to verify the model with variations of different circuit parameters. Furthermore, parameter sensitivity study, component parameter selection, and loss analysis are conducted to demonstrate the effectiveness of the model. The model is therefore proposed as an effective tool to assist the design and optimization of the brushless excitation system.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Linear Amplifier-Based Power-Hardware-in-the-Loop Emulation of a Variable
           Flux Machine
    • Authors: K. S. Amitkumar;Rajendra Thike;Pragasen Pillay;
      Pages: 4624 - 4632
      Abstract: Emulation of an electric machine allows the testing of a drive inverter and controller of an electric drive system, prior to the manufacture of a machine prototype. This paper presents the emulation of a variable flux machine (VFM). The VFM emulator system proposed in this paper uses a detailed look-up table-based machine model for the purpose of emulation. This allows the emulator to mimic all machine magnetic and geometric behaviors such as saturation and torque ripple. In addition, the machine emulator proposed in this paper uses high-performance high-bandwidth linear amplifiers as power amplifiers. This enables a high bandwidth; leading to a high accuracy machine emulation. A detailed control description for the proposed machine emulator system and a machine model look-up table data verification against a prototype machine is initially presented. Experimental results are then presented to validate the utility of the proposed VFM emulator system to emulate various machine transient behaviors at different magnetization levels. Experimental results obtained from the emulator are subsequently compared against the experimental results obtained from a prototype VFM drive to verify the emulation accuracy.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A High Speed PM Generator for an Organic Rankine Cycle System
    • Authors: Grazia Berardi;Nicola Bianchi;Daniel Gasperini;
      Pages: 4633 - 4642
      Abstract: This paper deals with the design guidelines of a high-speed permanent magnet generator used in an organic Rankine cycle system. These systems require an overall analysis that includes electromagnetic as well as mechanical aspects. Two important design aspects are taken into account. First, the design of the retaining sleeve is considered, since it influences both mechanical and magnetic aspects. Second, friction losses in the air gap and rotor losses due to current and MMF harmonics are considered. An in-depth design analysis is proposed and validated by experimental tests.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Power Factor Analysis and Maximum Power Factor Control Strategy for
           Six-Phase DC-Biased Vernier Reluctance Machines
    • Authors: Zixiang Yu;Wubin Kong;Dawei Li;Ronghai Qu;Chun Gan;
      Pages: 4643 - 4652
      Abstract: Different from the regular ac machines, the armature winding current waveforms of dc-biased vernier reluctance machines (DC-biased-VRMs) are sinusoidal with dc bias. The power factor (PF) calculation process also shows great difference. This paper intends to analyze the PF theoretically based on the mathematical model. Then, investigate the approach to optimize the PF and the price to pay if measures are taken to further improve the PF. The PF of the DC-biased-VRM is expressed under synchronous rotating frame. A maximum PF control strategy is proposed by adjusting the distribution of three-dimensional dq0-axis currents. The scale of active power to reactive power is changed, and the PF can be regulated. Experimental results are provided to verify the validity of the theoretical analysis.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Cogging Torque Minimization and Performance of the Sub-Fractional HP BLDC
           Claw-Pole Motor
    • Authors: Stefan Leitner;Hannes Gruebler;Annette Muetze;
      Pages: 4653 - 4664
      Abstract: Cogging torque reduction measures are hardly applied to low-cost sub-fractional hp brushless direct current (BLDC) motors, because the additional fabrication operations involved typically increase both the manufacturing complexity and cost significantly. By proposing an innovative punching layout, this paper shows how to minimize the high cogging torque of the mass-produced single-phase outer-rotor BLDC claw-pole motor—opposed to conventional cogging torque reduction—with no increase to the manufacturing cost. Systematically, a way is presented in which the selected introduction of auxiliary slots can double the cogging torque fundamental frequency, making stator claw skewing much more effective in reducing the cogging torque; both measures can be included at the stage of punching the steel sheets and subsequent deep-drawing thereof, at no additional cost. A detailed analysis of the effects of the cogging torque reduction measures on the most important motor performance parameters is conducted. The findings show that, with the exception of a three percentage point reduction in the efficiency, the proposed design can reduce the peak-to-peak cogging torque by 70% in both the simulations and experiments. The reduction in the cogging torque translates into a reduction in the output torque ripple of 17%, ensuring smoother operation especially at low speeds.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Design Method of a Direct-Drive Permanent Magnet Vernier Generator for a
           Wind Turbine System
    • Authors: Byungtaek Kim;
      Pages: 4665 - 4675
      Abstract: In this study, a novel design method of a direct-drive (DD) permanent magnet vernier generator (PMVG) is proposed for a gearless, high-power, and lightweight wind turbine system. Once the maximum power requirement is given, the base and maximum speeds of the generator are first obtained from aerodynamic characteristics of the wind turbine blade. Then the necessary electrical circuit parameters of the generator are scoped with consideration of the maximum torque per ampere control scheme of a permanent magnet generator. To determine the generator geometries satisfying the scoped parameters, the correlations between the parameters and geometries of a PMVG with concentrated windings are deduced. Using the deduced correlations and the obtained parameters, a systematic design procedure of a PMVG is proposed. For a case study, a 5-kW DD-PMVG with the outer rotor is designed through the proposed method. The performance characteristics of the designed generator are analyzed with finite-element simulations and compared with analytically predicted results. Finally, the experimental results are provided.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • IE5 Energy-Efficiency Class Synchronous Reluctance Motor With Fractional
           Slot Winding
    • Authors: Vladimir Dmitrievskii;Vladimir Prakht;Vadim Kazakbaev;
      Pages: 4676 - 4684
      Abstract: This paper considers an optimization of the IE5 four-pole synchronous reluctance motor of a new design. The motor has an original rotor design and a stator with a fractional-slot winding (2.5 slots per pole and phase). The target parameters of optimization are the resulting efficiency of the motor at the fan load profile, the torque ripple, the required power of the frequency converter, and the total harmonic distortion of the supply voltage. The motor efficiency is much higher than the IE5 class requirement and remains high in wide range of powers at the fan load profile. Also, the motor has low torque ripple despite that its rotor and stator have no skewing.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Induction Machine Rapid Performance Test
    • Authors: Maher Al-Badri;Pragasen Pillay;Pierre Angers;
      Pages: 4685 - 4691
      Abstract: Efficiency Test Method A is used in industry to determine the efficiency of induction motors. However, in this method, which is carried out by using a dynamometer, the machine under test shall be brought up to its thermal equilibrium before the data can be collected. This requires running the machine under full load for a considerable amount of time (around 8-h), which implies high cost associated with this test. This paper presents a new simple technique that can significantly reduce the time required for induction machine full-load tests. The proposed technique needs only 30 min of a machine run under full-load conditions. The temperature–speed relationship is the key point in this research work. This relationship is utilized to estimate the machine's full-load temperature. The accuracy of the proposed algorithm is validated by testing two small and two medium-sized machines. The results show acceptable level of accuracy, when they are compared to the corresponding 8-h dynamometer tests conducted on the same machines. The technique can save time and cost associated with the dynamometer test. The proposed algorithm is valid only for totally enclosed fan-cooled type induction motors.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Optimized Design of PMSM With Hybrid-Type Permanent Magnet for Improving
           Performance and Reliability
    • Authors: Chae-Lim Jeong;Young-Kyoun Kim;Jin Hur;
      Pages: 4692 - 4701
      Abstract: This paper proposes an optimized design of permanent magnet (PM) synchronous motor (PMSM) using hybrid-type PM for improving the output characteristics and reliability. Here, the hybrid-type PM is defined as using both neodymium PM (Nd-PM) and ferrite PM (Fe-PM) in a rotor. First, a basic design of PMSM is conducted by considering the magnetic equivalent circuit and applying the magnetic characteristic of Fe-PM changed by the reversed flux of Nd-PM. For optimizing the motor using hybrid-type PM, parallel configuration of reluctance factors is helpful for increasing the output characteristics, and it is analyzed by using a finite element method (FEM). In addition, by using an algorithm, an optimized design is suggested for obtaining maximum torque. The performances of target and proposed motors are compared through FEM. Next, the irreversible demagnetization of each motor is analyzed at high and low temperature, and the demagnetization phenomenon of two-type motors is compared for verifying the reliability of the proposed motor. Finally, prototypes of reference and proposed models are developed for evaluating the enhanced performance through comparison between the two motors.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Numerical and Analytical Approaches to the Modeling of a Spoke Type IPM
           Machine With Enhanced Flux Weakening Capability
    • Authors: Nada Elloumi;Mauro Bortolozzi;Ahmed Masmoudi;Mario Mezzarobba;Matteo Olivo;Alberto Tessarolo;
      Pages: 4702 - 4714
      Abstract: Interior permanent magnet (IPM) machines with spoke-type design are very attractive for several applications, including vehicle traction, which requires a good flux weakening performance to achieve high speed. For this purpose, a high demagnetizing current is usually injected to reduce the machine flux at high speed, with detrimental effect in terms of efficiency. This problem can be mitigated by equipping the rotor with a mechanical flux weakening device, which activates during high-speed operation by centrifugal force. This paper addresses the analytical modeling of this special kind of IPM motor through a simplified magnetic equivalent circuit (MEC) approach, which incorporates saturation and slotting effects as well as the flux weakening device operation. It is shown how the MEC model can effectively describe the IPM machine behavior despite its simplicity. Results are successfully validated by comparison both with finite element analysis, which requires much more computational resources, and with measurements from laboratory prototype testing.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Analysis of Orbital Eccentricity and UMP in Large Salient Pole Synchronous
           Machines
    • Authors: Jorge Johnny Rocha Echeverria;Paulo Victor Viana da Silva;Edson da Costa Bortoni;
      Pages: 4715 - 4722
      Abstract: The problem with unbalanced magnetic pull (UMP), often analyzed for induction motors, is also a huge issue in large hydro generators. This paper focuses on large vertical shaft synchronous machines describing the UMP as a function of eccentricity, irrespective of its origin on the rotor, stator, or both. The static and the dynamic eccentricity impact on the air-gap length is described through an original mathematical model in which the magnetic flux density spatial distribution is amplitude modulated and the UMP is calculated applying Maxwell's tensor. This process allows including the machine saturation when calculating the no-load rated voltage. Hence, with constant rotor excitation current, corresponding to the rated generator voltage at no-load, the magnetic field amplitude variation results in a linear function of the air-gap length variation. Seven case studies are presented comparing traditional methodology with the proposed one. Two of them are also calculated by applying the finite element method (FEM). The proposed methodology gets more realistic answers if FEM results are taken as a reference. Finally, UMP triggered by a dynamic eccentricity is shown, and the resulting force that followed the orbital eccentricity is depicted clearly.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Novel Hybrid Excited Doubly Salient Machine With Asymmetric Stator Poles
    • Authors: Mingjie He;Wei Xu;Jianguo Zhu;Lei Ning;Guanghui Du;Caiyong Ye;
      Pages: 4723 - 4732
      Abstract: A novel hybrid excited asymmetric stator pole doubly salient machine (HEASPDSM) is proposed in this paper. The new topologies and operational principle are first investigated by using a simplified equivalent magnetic circuit model. The harmonic components of air-gap flux density are then analyzed. The influence of key structural parameters of the proposed machine on the flux regulation ability and torque is studied. A full comparison on main electromagnetic performance indexes of the proposed 12/7 (stator/rotor poles) HEASPDSPM and several traditional doubly salient machines is presented. A prototype is fabricated and tested to validate the theoretical analysis. The results well demonstrate that the HEASPDSPM possesses various merits, such as strong flux regulation capability, high torque density, low cogging torque, and low torque ripple.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Design and Analysis of a Novel PM-Assisted Synchronous Reluctance Machine
           Topology With AlNiCo Magnets
    • Authors: Seyede Sara Maroufian;Pragasen Pillay;
      Pages: 4733 - 4742
      Abstract: The absence of field excitation on the rotor of the synchronous reluctance machine, results in poor power factor and low power density when compared to permanent magnet synchronous machines. To mitigate these problems, permanent magnet-assisted synchronous reluctance machines were introduced. The inserted permanent magnet boosts the machine's power factor and enhances its power density. In this paper, a new topology for permanent magnet-assisted synchronous reluctance machines using low cost AlNiCo magnets is proposed. The results of the proposed design with various magnet dimensions using AlNiCo magnets are compared with a previously designed and prototyped synchronous reluctance machine. Simulations for the same magnet dimensions are also carried out using a rare earth magnet material to study the effect of magnet type on the machine's performance. A final design using AlNiCo magnets is chosen based on the gain in the power density, manufacturing cost, torque ripple, and the power factor improvement. A rotor prototype is manufactured based on the selected topology and tested under various operating conditions.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Experimental Investigations on Passively Levitated Electrodynamic Thrust
           Self-Bearing Motors
    • Authors: Joachim Van Verdeghem;Virginie Kluyskens;Bruno Dehez;
      Pages: 4743 - 4753
      Abstract: Recent researches have revealed that electrodynamic thrust bearings can gather, within one single armature winding, both the passive axial restoring force and the driving torque, thus yielding a new passively levitated electrodynamic thrust self-bearing (EDTSB) motor. Although their operation principle and the model describing their axial and spin dynamics have already been corroborated, experimental results still lack to properly characterize these machines. In this context, this paper is devoted to an in-depth experimental investigation of an EDTSB motor. Measurements performed on the prototype endorse the assumptions regarding the linearization of the flux linkages as well as the negligible impact of the magnetic field harmonic content. They also disclose that suspension currents are induced even when the rotor is centered. Finally, the thrust bearing and self-bearing motor behaviors are studied in quasi-static and dynamic conditions, validating the dynamical model.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Parameter Identification of Current–Force Factor and Torque Constant in
           Single-Drive Bearingless Motors With Back EMF
    • Authors: Hiroya Sugimoto;Akira Chiba;
      Pages: 4754 - 4761
      Abstract: One-axis actively positioned bearingless motors are studied for industry applications such as pumps and cooling fans. In particular, single-drive bearingless motors have a great advantage of having a simple regulation system. Only one three-phase inverter is required to generate both torque and a magnetic suspension force by the q- and d-axis currents, respectively. Therefore, their voltage equation is unique. In addition to the rotational speed induced voltage in the q-axis, the translation speed voltage is generated in the d-axis. Therefore, both the current–force factor and the torque constant can be identified from the back electromotive force (EMF). In this paper, a novel simplified identification method of the current–force factor is proposed that does not require the measurement of the active axial force and current. Furthermore, it is experimentally verified that this method is effective in the identification of machine parameters.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Flux-Linkage-Based Current Control of Saturated Synchronous Motors
    • Authors: Hafiz Asad Ali Awan;Seppo E. Saarakkala;Marko Hinkkanen;
      Pages: 4762 - 4769
      Abstract: Magnetic saturation characteristics of synchronous reluctance motors (SyRMs), with or without permanent magnets, are highly nonlinear. These nonlinear effects can be included in the current controller by changing its state variable from the stator current to the stator flux linkage using the known saturation characteristics. A direct discrete-time variant of the flux-linkage-based current controller is developed in a state-space framework. If the magnetics are modeled to be linear, the proposed control structure reduces to the standard current controller in this special case. Experimental results on a 6.7-kW SyRM drive demonstrate that the proposed flux-linkage-based controller enables a higher closed-loop bandwidth and is more robust against parameter errors, as compared to the standard current controller.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Performance Comparison Between Two-Level and Three-Level SiC-Based VFD
           Applications With Output Filters
    • Authors: Seunghoon Baek;Younghoon Cho;Byung-Geuk Cho;Chanook Hong;
      Pages: 4770 - 4779
      Abstract: One of the recent trends in power electronics field is to achieve high efficiency and compact size by using wide bandgap power devices such as silicon carbide (SiC) or gallium nitride switches. This paper compares the efficiency, the motor terminal voltage quality (dv/dt), and the common mode current of the SiC-based variable frequency drives (VFDs) according to the inverter topologies with and without the output filters. For this purpose, both the 2-level (2L) and 3-level (3L) topologies with SiC devices are built and tested. Here, the well-known 2L half-bridge inverter is compared with the well-known 3L T-type neutral point clamped inverter. A dv/dt filter and a sine wave filter have been discussed to satisfy the National Electrical Manufacturers Association standards as well. The experiments have been carried out with a 380-V/60-Hz, 3.7-kW induction motor and the custom designed power stages. Additionally, the experiments with both a 3-m and a 50-m cable length between the VFD and the induction motor are performed and reported.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Current Observer to Reduce the Sensor Count in Three-Phase PM
           Synchronous Machine Drives
    • Authors: Michael Eull;Mustafa Mohamadian;Daniel Luedtke;Matthias Preindl;
      Pages: 4780 - 4789
      Abstract: Reduced sensor systems are a topic receiving increasing attention as manufacturers seek to reduce costs by removing components from systems. One popular option is to remove phase current sensors and to estimate the missing currents using the ones remaining. This paper proves that it is possible to estimate the three-phase currents of an anisotropic permanent-magnet synchronous machine drive when only one-phase current sensor is present. The necessary conditions for observability and stability have been derived, providing certainty for the design of a permanent-magnet synchronous machine drive controller. The concept has been verified with high-fidelity simulations and experiments that show the one-phase current sensor observer is capable of controlling the drive system in the presence of sensor noise and significant parameter errors. The proposed phase current observer can be used to remove one sensor from a drive system by employing the two sensor observer with the one sensor observer acting as a failsafe.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • PM-Assisted Synchronous Reluctance Machine Drive System for Micro-Hybrid
           Application
    • Authors: Lei Hao;Chandra S. Namuduri;Suresh Gopalakrishnan;Chandra Mouli Mavuru;Prasad Atluri;Thomas W. Nehl;
      Pages: 4790 - 4799
      Abstract: The demand for increased power and improved fuel economy are driving changes in alternator technology for automotive applications. To meet these demands requires a drive system with capabilities of torque assist, regenerative braking and power generation to supply vehicle loads while keeping the battery charged. Furthermore, to minimize add-on cost, the system must be air-cooled with minimal changes to the vehicle hardware and operate at 12 V with the same or smaller packaging footprint of the current alternator. In this paper, a low cost 12 V, 4 kW air-cooled permanent magnet-assisted synchronous reluctance machine drive system for a micro-hybrid vehicle is presented. The design and analysis in terms of machine, inverter, controller, and control algorithm are discussed in detail. Thermal performance of the system under different operating conditions, which is another key aspect for the harsh environment application, is also studied. Fuel economy analysis of the proposed low-cost micro-hybrid system for a Segment B vehicle shows significant reduction in fuel consumption resulting in a direct benefit to the customer. Finally, a prototype drive system was built and tested and found to meet the cost, performance, and packaging requirements.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Current Regulation in Parallel Combined Winding Bearingless Motors
    • Authors: Yunlei Jiang;Renato Amorim Torres;Eric Loren Severson;
      Pages: 4800 - 4810
      Abstract: To improve power density and motor performance, new bearingless motor topologies combine torque and magnetic suspension coils into a single winding. Of these topologies, the parallel dual-purpose no-voltage winding is advantageous from the bearingless drive perspective because it requires the least amount of hardware. However, this topology can result in undesirable current controller performance from cross-coupling effects between the suspension and torque operation. This paper investigates these cross-coupling effects using rotating reference frame theory to derive relevant system disturbance transfer functions. The nature of this coupling is explained in relation to the machine and control parameters (inductances, resistances, controller gains) to provide insights for bearingless machine and control designers. The paper proposes and simulates different compensation techniques to minimize or eliminate the cross-coupling. It is shown that with careful machine design or with proper feedback control compensation, the motor controller can be implemented as a conventional motor drive, without knowledge of the magnetic suspension system. Finally, experimental validation is provided via two prototype machines.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Stator-Flux-Oriented Control of Synchronous Motors: A Systematic Design
           Procedure
    • Authors: Hafiz Asad Ali Awan;Marko Hinkkanen;Radu Bojoi;Gianmario Pellegrino;
      Pages: 4811 - 4820
      Abstract: This paper deals with stator-flux-oriented control of permanent-magnet (PM) synchronous motors and synchronous reluctance motors (SyRMs). The variables to be controlled are the stator-flux magnitude and the torque-producing current component, whose references are easy to calculate. However, the dynamics of these variables are nonlinear and coupled, potentially compromising the control performance. We propose an exact input–output feedback linearization structure and a systematic design procedure for the stator-flux-oriented control method in order to improve the control performance. The proposed controller is evaluated by means of experiments using a 6.7-kW SyRM drive and a 2.2-kW interior PM synchronous motor drive.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Real-Time Real-Power Emulator of a Medium-Voltage High-Speed Induction
           Motor Loaded With a Centrifugal Compressor
    • Authors: Kenichiro Saito;Hirofumi Akagi;
      Pages: 4821 - 4833
      Abstract: This paper provides an experimental discussion on a real-time real-power emulator that plays an important role in achieving a total test of medium-voltage, high-power, high-speed induction motor drives. The use of the emulator brings cost and time savings to the test. The test bench including the emulator is characterized by connecting two modular multilevel double-star chopper-cell (DSCC) converters connected in a front-to-front way. This paper designs, builds, and tests a 400-${rm V}_{rm dc}$, 10-kW downscaled test bench. It mainly consists of the following two identical DSCC converters: 1) one DSCC converter is used as an inverter under test; and 2) the other as a real-time real-power high-fidelity emulator. Experimental waveforms confirm that the emulator can reproduce electrical and mechanical operating performance of the three-phase 200-V, 10-kW, four-pole, 9000-r/min induction motor loaded with a centrifugal compressor.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Novel Four-in-One Variable Frequency Drive Topology
    • Authors: Mahesh M. Swamy;
      Pages: 4834 - 4845
      Abstract: Of late, most types of ac motors can be operated using variable frequency drives (VFDs) by merely selecting the type of motor and the corresponding control method using a sophisticated all-in-one software platform. As technology improves, the VFD is becoming more of a plug and play, software-based electrical equipment. There have been no comparable technological advancement/improvements in the hardware realm except for the potential use of wide band gap devices (SiC or GaN) to reduce losses. The idea being proposed here is a hardware platform that is similar to an all-in-one software platform. By reconfiguring the hardware platform, one could achieve totally new or additional features that can enhance the overall performance of a VFD. It is shown that by adding one small hardware device as part of the main VFD, the unit can be reconfigured to provide four distinct features/functions as desired. An off-the-shelf VFD is used as an example to illustrate the various configurations achievable based on the proposed hardware modification. The proposed topology's cost, size, and features are compared with a traditional VFD with externally added components to achieve similar features/functions. In addition, the amount of time estimated to be saved in developing the proposed four-in-one converter compared to developing individual, external units to achieve similar features and functions is also investigated.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Zero-Cost Closed-Loop Discharging Method for Modular Multilevel Converter
           Submodules Without External Circuits
    • Authors: Jianyu Pan;Ziwei Ke;Muneer Al Sabbagh;Risha Na;Julia Zhang;Jin Wang;Longya Xu;
      Pages: 4846 - 4854
      Abstract: A novel submodule capacitor discharging control strategy is proposed and implemented for modular multilevel converters (MMCs). By sequentially controlling the arm currents of an MMC, all submodule capacitors are discharged rapidly through internal arm resistors without additional devices and circuits, resulting in improved performance and reduced cost. A closed-loop control method is investigated for the effectiveness of the new control strategy. A comparison study is evaluated between the proposed method and the traditional methods using bleeding resistors, auxiliary resistors, and load resistors. Validated by the simulation and experiment, the proposed method has the maximum benefits including zero hardware cost, fast discharging time, and negligible load current impact.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Open-Circuit Fault Diagnosis and Fault Tolerant Operation of Interleaved
           DC–DC Boost Converters for Homes and Offices
    • Authors: Fernando Bento;Antonio J. Marques Cardoso;
      Pages: 4855 - 4864
      Abstract: The use of electronic equipment and other dc-compatible appliances in homes and offices is increasing at a very fast rate, as well as the distributed generation of energy. These two statements will most likely trigger, in a near future, the adoption of district-scale dc grids, connecting dc microgeneration plants and consumers, in an effort to cut the number of conversion steps required to deliver power to dc appliances. DC–DC converters will be fundamental in these systems, allowing the establishment of several voltage levels. The reliability of these converters plays a critical role, ensuring service continuity of the loads connected to them. With the increment of reliability in mind, this paper proposes a simple yet effective open-circuit fault diagnostic method suitable for interleaved dc–dc boost converters, but equally functional for other dc–dc converter topologies. The improvements introduced in this paper greatly simplify the diagnostic action, while making the correct diagnostic of faults independent of the switching duty cycle. Moreover, an alternative reconfiguration scheme is proposed to mitigate the adverse impacts of such faults. To prove the effectiveness of these strategies, a three-phase interleaved boost converter prototype was used in the experiments.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • System-Level Reliability-Oriented Power Sharing Strategy for DC Power
           Systems
    • Authors: Saeed Peyghami;Pooya Davari;Frede Blaabjerg;
      Pages: 4865 - 4875
      Abstract: Power converters are one of the failure sources in modern power systems, and hence driver of maintenance and downtime costs, which should be reduced by reliable design, control, and operation of converters. This paper proposes a power sharing control strategy for evenly distributing the thermal stresses among dc converters in dc microgrids, and consequently enhancing the overall system reliability. The aim of this paper is to extend the aging process of failure prone converters by adjusting their loadings. The proposed approach employs the prior experienced thermal damages on the converter's fragile components in order to adjust its contribution on demand supply. According to the proposed strategy, the higher the thermal stress on a converter is, the lower the power it will supply. As a result, the overall system reliability will be improved. A numerical case study on a dc microgrid is presented to illustrate the effectiveness of the proposed power sharing strategy. Moreover, experimental tests are provided to demonstrate the applicability of the reliability-oriented power sharing method.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Sensorless Unbalance Modeling and Estimation as an Ancillary Service for
           LV Four-Wire/Three-Phase Power Converters
    • Authors: Andres Suárez-González;Pablo García;Ángel Navarro-Rodríguez;Geber Villa;Jose M. Cano;
      Pages: 4876 - 4885
      Abstract: This paper describes a method to provide low-voltage four-wire three-phase power converters with the capability of unbalance estimation as an ancillary service to the main role that they play in the distribution system (distributed generator, energy storage system, drive, etc.). Typically, dedicated grid/load current sensors are needed to effectively comply with unbalance compensation tasks, increasing system cost and reducing reliability. This is due to the difficulties that arise in the extraction of the zero- and negative-voltage components from the voltages at the point of common coupling, such as the inadequate resolution of full-scaled voltage sensors and limited spectral separation. In this paper, the proposed method does not rely on additional sensors to those typically used in voltage-source converters, and in any case, those sensors are limited to the point of connection of the power converter. Impedance estimation only using converter-side current sensors is implemented by adding a high-frequency voltage excitation over the fundamental command. A new model approach is proposed for the real-time extraction of system impedance using a complex-valued compact form. Considering the voltage source at that frequency to be unique in the grid, it will be proved that the impedance and, thus, the resulting negative-sequence current, which is used for unbalance compensation, can be estimated. For the zero sequence, a special arrangement of the converter voltage sensors together with a repetitive controller is used.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Improved Performance With Dual-Model Predictive Control for Cascaded
           H-Bridge Multilevel Converter
    • Authors: Merlin Chai;Naga Brahmendra Yadav Gorla;Sanjib Kumar Panda;
      Pages: 4886 - 4899
      Abstract: There has been increasing interest in solid-state transformers (SSTs) as a future replacement for conventional distribution transformers as it is able to provide ancillary services in addition to step-up/step-down of voltages. In SSTs, a common topology used in the ac–dc stage is the cascaded H-bridge (CHB) multilevel converter. This paper proposes a novel dual-model predictive control method for the CHB multilevel converter with faster dynamic response, improved harmonic performance, and voltage balancing of the CHB cells. The primary model enables conventional control over source current and output voltages, whereas the secondary model is able to generate the reference source current through power modeling, which eliminates the need for a proportion-integral (PI) controller, thus resulting in faster dynamic response. A Luenberger-based observer is also implemented to estimate the dc load current in each CHB cell. The second-order harmonic notch filter and the CHB cell dc voltage balancing cost function aim at improving the performance of the source current and CHB cell dc voltages, respectively. The proposed control techniques are then validated under steady-state and transient conditions through simulation and experiment with a laboratory prototype.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Si-IGBT-Based Solution to Drive High-Speed Electrical Machines
    • Authors: Vito Giuseppe Monopoli;Pierluigi Sidella;Francesco Cupertino;
      Pages: 4900 - 4909
      Abstract: High-speed electrical drives normally require converters capable of high-frequency operation. For this reason, converters based on SiC mosfets have been spreading in this field. Nevertheless, the problems caused by the high dv/dt imposed by SiC mosfets, like the premature failure of the motor winding insulation and the electromagnetic interference generation, are drawing more and more attention of the experts of this sector. In fact, these issues can deeply affect the system reliability and, hence, can represent a limiting factor for all those applications where the continuity of operation is the highest priority. To avoid the use of SiC mosfets in the most sensitive applications, this paper presents a solution, which consists of a Si-insulated gate bipolar transistor (IGBT)-based inverter fed by a Si-IGBT-based dc/dc converter performing a suitable dc voltage regulation. Therefore, the aim of this paper is to prove that a stable operation of a high-speed drive can be guaranteed through the proposed converter configuration. To prove the effectiveness of the proposed solution, experimental results on a laboratory setup have been presented.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Three-Port Isolated Three-Phase Current-Fed DC–DC Converter Feasible
           to PV and Storage Energy System Connection on a DC Distribution Grid
    • Authors: Raimundo Nonato Moura de Oliveira;Luan Carlos dos Santos Mazza;Herminio Miguel de Oliveira Filho;Demercil de Souza Oliveira;
      Pages: 4910 - 4919
      Abstract: This paper presents a three-port three-phase current-fed dc–dc converter with high-frequency isolation and bidirectional power flow. Port I is fed by a battery bank, port II employs a set of photovoltaic modules, and port III is connected to a dc link. The topology uses three single-phase H-bridge cells in the primary side and a three-phase H-bridge converter in the secondary one. High-frequency isolation is ensured by three single-phase transformers connected in an open delta-wye configuration. The theoretical analysis is performed considering the fundamental component of the voltage across the transformers. Maximum power point tracking, the battery current, and the power flow between the primary and secondary sides are controlled by the use of variable duty cycle technique in the primary side and the use of phase-shift technique between the primary and secondary bridges. In order to validate the study, experimental results of the proposed system considering the dc rated voltages as 48 V/96 V/380 V for Ports I/II/III, respectively, and rated power of 3.5 kW are carried out.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Grid-Tied Inverter With AC Voltage Sensorless Synchronization and Soft
           Start
    • Authors: Diego Pérez-Estévez;Jesús Doval-Gandoy;
      Pages: 4920 - 4933
      Abstract: This paper presents a novel grid synchronization method with bumpless start that requires minimal computational load and can selectively track the positive sequence of the grid voltage in an unbalanced and distorted three-phase weak grid. Only 12 floating-point operations are required to obtain the in-phase and quadrature components that define a synchronous frame which tracks the positive sequence of the grid voltage. Contrary to a phase-locked loop (PLL), the presented scheme does not require to measure any ac voltages. Therefore, this sensorless method is particularly suited for weak-grid conditions, in which the voltage at the point of common coupling may contain significant noise and can experience larger deviations from the grid voltage (compared to a strong grid) due to the voltage drop in the weak grid impedance. The error in the estimated phase depends on the accuracy of the plant model. If the LCL filter parameters are known, then both the proposal and a PLL-based scheme result in the same steady-state error. Experimental results show the advantages of the proposal compared to a moving average filter PLL.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Microwave Tube Fault-Current Model for Design of Crowbar Protection
    • Authors: Subhash Joshi T.G.;Vinod John;
      Pages: 4934 - 4943
      Abstract: Many applications that use high-energy plasma are realized using microwave tubes (MWT) that operate at peak power in the range of hundreds of MW and frequency in GHz. One failure mode of the MWT is due to the excess energy in the tube during internal arcing events. Crowbar is used to protect the MWT by diverting the energy during fault. To compute the energy released into the MWT, the dc fault current model and the MWT model are essential. An equivalent fuse wire model is utilized for the MWT for the crowbar applications. The paper proposes a model for the dc fault current, the analysis for which is based on Joules Integral energy concept. The model provides flexibility to choose a range of practically observed reactance to resistance ratio ($X{/}R$) of transformer and also allows the use of a range of dc current-limiting resistances that are utilized in the high-voltage (HV) power supply circuits in microwave applications. The nonlinearity of the system due to the multipulse diode rectifier is also considered by introducing a correction factor in the model. This paper shows that the same correction factor can be applied for both dc side parallel- and series-connected rectifier circuits. Both dc fault current and MWT models are verified experimentally. Using the model, a 10 kV, 1 kA crowbar is built to limit the energy in MWT below 10 J.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Analysis and Control of Neutral-Point Deviation in Three-Level NPC
           Converter Under Unbalanced Three-Phase AC Grid
    • Authors: Kyungsub Jung;Yongsug Suh;
      Pages: 4944 - 4955
      Abstract: This paper presents a neutral-point deviation and ripple compensating control method applied to a three-level neutral-point-clamped (NPC) converter. The neutral-point deviation and its harmonic components are analyzed with a focus on the average current flowing through the neutral-point of the dc link. This paper also proposes a control scheme compensating for the neutral-point deviation and dominant harmonic components under generalized unbalanced grid operating conditions. The positive and negative sequence components of the switching functions and ac input currents are employed to accurately explain the behavior of three-level NPC converter. Simulation and experimental results are presented to verify the validity of the proposed method.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Implementation of PMSM Drive for a Solar Water Pumping System
    • Authors: Shadab Murshid;Bhim Singh;
      Pages: 4956 - 4964
      Abstract: This paper proposes the design and experimental investigation of fuzzy precompensated hybrid proportional-integral (PI) controller for a permanent magnet synchronous motor (PMSM)-driven standalone solar water pumping system. A conventional PI controller usually has fixed gains, which makes them quite sensitive to the parameter variations. In order to improve its performance, both during dynamic and steady-state conditions, the presented controller introduces a fuzzy logic controller, which processes the speed error. The speed along with the processed output is inputted to the PI controller for speed control of PMSM. This topology uses a solar photovoltaic (PV) array to convert the solar power into electrical power. The energy obtained is utilized to rotate the PMSM using a 3-φ voltage-source inverter. The PMSM is coupled to a pump, which performs the water pumping. An intermediate stage dc–dc converter is utilized to maximize the power output using an incremental conductance algorithm. A PV feed-forward term is incorporated to provide an accelerated performance. This topology is modeled and its response is manifested through simulation studies using MATLAB/Simulink under different atmospheric conditions. A hardware validation of it is also carried out using a digital signal processor controller (dSPACE DS-1004) on a developed laboratory prototype.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Modulation Methods for 3L-NPC Converter Power Loss Management in STATCOM
           Application
    • Authors: Jiuyang Zhou;Po-Tai Cheng;
      Pages: 4965 - 4973
      Abstract: The uneven power loss distribution among the semiconductor devices is one critical issue of the three-level neutral-point clamped converter. Besides, different operating conditions will result in different loss distribution profiles. The case with low power factor and high modulation usage, which is common in the static synchronous compensator (STATCOM) application, has not been paid much attention to in the literature. In this paper, the power loss distribution under this condition is discussed. And a novel carrier-based modulation technique is proposed to balance the power loss distribution and reduce the power loss in the most stressed device. In addition, an active neutral-point (NP) voltage balancing control strategy is also proposed based on the proposed modulation scheme. Simulation and laboratory results are presented to verify the performances of the proposed modulation technique in power loss redistribution and NP voltage control. Its influence on the output current harmonic performance is also evaluated.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Scale-Up Methodology of a Modular Multilevel Converter for HVdc
           Applications
    • Authors: Mohammed Alharbi;Subhashish Bhattacharya;
      Pages: 4974 - 4983
      Abstract: Modular multilevel converters (MMCs) are a realistic alternative to the conventional voltage source converters for medium-voltage (MV) and high-voltage direct current (HVdc) applications. The number of submodules (SMs) per arm of the MMC can be as high as 512 to achieve desired high dc voltage levels required for HVdc with a very low total harmonic distortion (THD) (e.g.,
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Computational-Efficient Thermal Estimation for IGBT Modules Under Periodic
           Power Loss Profiles in Modular Multilevel Converters
    • Authors: Yi Zhang;Huai Wang;Zhongxu Wang;Frede Blaabjerg;
      Pages: 4984 - 4992
      Abstract: One of the next challenges for modular multilevel converters (MMCs) is how to the size the critical components to their limits with reduced design margins, while at the same time fulfilling the reliability target. To do it confidently, better thermal modeling with quantitative uncertainty analysis is necessary to support the decision-making during the product design stage. Regarding the conversion of long-term mission profiles into thermal profiles for reliability evaluation, this paper proposes a computationally efficient thermal modeling method for insulated-gate bipolar transistor modules in MMCs. The proposed method considers the impact of the inherent thermal unbalance and has minimum computation with quantitative error analysis. Finally, both simulations and experiments have verified the theoretical results.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Analysis and Design of a High-Frequency Isolated Full-Bridge ZVT CLL
           Resonant DC–DC Converter
    • Authors: Uday Patil;Nagendrappa Harischandrappa;
      Pages: 4993 - 5004
      Abstract: In this paper, a new pulsewidth modulated gating scheme and a zero-voltage transition (ZVT) auxiliary circuit is proposed for a fixed frequency full-bridge CLL dc–dc resonant converter with a capacitive output filter. An approximate complex ac circuit approach is used for the steady-state analysis of the converter. The optimum design of the converter is described with the help of design curves for a sample converter of 200-W power rating operating at a switching frequency of 100 kHz. The converter with applied gating scheme and ZVT auxiliary circuit provides zero-voltage switching to all the switches for the entire variations in loading and input voltage conditions ensuring higher conversion efficiency. PSIM simulations are carried out to verify theoretical predictions about the performance of the converter for various operating conditions. Finally, experimental results are provided to verify the feasibility of the proposed converter. The theoretical, simulation, and experimental results are given and discussed.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Compensation of Arm Current Sensor Errors in Modular Multilevel Converter
    • Authors: Negesse Belete Belayneh;Chang-Hwan Park;Jang-Mok Kim;
      Pages: 5005 - 5012
      Abstract: The modular multilevel converter (MMC) is an attractive topology for medium- or high-power applications due to its high modularity, scalability, and high-power quality. Even if a direct modulated control algorithm guarantees a stable operation for the MMC system, it is unable to suppress the flow of a negative sequence second order leg current in the MMC. Mostly, for circulating current suppression, a PI controller in the double fundamental frequency rotating reference frame is adopted. The three-phase leg currents are calculated using the average of upper and lower arm currents of the respective phase after they are measured by arm current sensors. However, the previous circulating current suppression controllers do not consider the offset and scale error of the arm current sensors. This paper proposes an algorithm to compensate the offset and scale error of the arm current sensors. The proposed algorithm is easy to be implemented and effectively suppresses the leg current components caused by the current sensor errors. The validity of the proposed algorithm is verified through both simulation and experimental results.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Module Integrated Buck Inverter: Analysis and Design
    • Authors: André Pacheco Meurer;António Manuel Santos Spencer Andrade;Marcello Mezaroba;Mário L. S. Martins;Hélio Leães Hey;
      Pages: 5013 - 5022
      Abstract: This paper proposes a new grid current controller for a photovoltaic (PV) module integrated buck inverter using a single pulsewidth modulation switch and an unfolding H-bridge, which significantly reduces switching losses. To achieve this, an internal grid current loop with active damping is presented with an LCL filter to connect it to the utility grid. The problem of the filter natural resonance is solved by means of a virtual impedance (active damping), demanding no additional sensor. Experimental results obtained from a 200-W prototype achieved a European efficiency of 96.27% with a current total harmonic distortion of 3.7%.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Optimization Platform to Find a Switching Pattern of Digital Active Gate
           Drive for Reducing Both Switching Loss and Surge Voltage
    • Authors: Yu Shan Cheng;Tomoyuki Mannen;Keiji Wada;Koutarou Miyazaki;Makoto Takamiya;Takayasu Sakurai;
      Pages: 5023 - 5031
      Abstract: A gate driving for power devices is a key technology to further improve switching characteristics. With the help of digital gate driver IC, the switching behavior of power devices can be enhanced even under high-speed switching. In this paper, an evaluation platform for determining the optimal switching pattern of an active gate drive control is proposed for an inverter circuit. A high speed optimization system is built up to search for an advantageous switching pattern that reduces total switching loss of two power devices in an inverter circuit and constrains surge voltage simultaneously. The proposed online optimization demonstrates its feasibility for the full-bridge inverter circuit, which is rated at 500 V with digital active gate drive control. Experimental results show that the proposed optimization system is able to obtain optimal switching pattern from $64^{60}$ possible combinations of switching patterns within 15 min, which is 6 times faster than the previous study. Optimizations can also conducted under different load current conditions. Eventually, the obtained optimal pattern yields up to 42% reduction in the total switching loss when it constrains surge voltage to minimum compared with the conventional driving pattern.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Modular Design Approach to Provide Exhaustive Carrier-Based PWM Patterns
           for Multilevel ANPC Converters
    • Authors: Yuzhuo Li;Yun Wei Li;Hao Tian;Navid R. Zargari;Zhongyuan Cheng;
      Pages: 5032 - 5044
      Abstract: The number of applicable carrier-based pulsewidth modulation (PWM) patterns increases with the growth of output levels in scalable multilevel topologies, such as active-neutral-point-clamped (ANPC) converters. Therefore, it is hard to optimize PWM for such topology, especially with large output levels. In this paper, a simplified and modular carrier-based PWM design approach for multilevel ANPC converters is proposed. Inspired by the decomposition theory, the topology decomposition is introduced in this paper to decompose an N-level ANPC converter into low-level subtopologies. Then, the complete set of applicable PWM patterns is derived based on ANPC operation principles, which makes it possible to optimize the performance based on the various requirements in applications. Meanwhile, the carrier-based PWM is implemented through the utilization of subtopologies with low-level modulation schemes, such that the design process of carrier-based PWM is greatly simplified and modularly realized. Both the complete PWM patterns and PWM design examples with experimental results of several ANPC converters are provided to show the feasibility and modularity of the proposed method.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Integration of Inductors, Capacitors, and Damping Into Bus Bars for
           Silicon Carbide Inverter dv/dt Filters
    • Authors: Andy Schroedermeier;Daniel C. Ludois;
      Pages: 5045 - 5054
      Abstract: A dv/dt filter is useful to mitigate the deleterious effects of voltage pulses with high edge rates, such as voltage overshoot and ringing in motor drive systems, which can cause premature motor failure. With the introduction of wide-bandgap semiconductor drives, these issues will become more pronounced. This paper introduces a new type of dv/dt filter where the inductor, capacitor, and damping resistor are integrated into the output bus bar or cable of a silicon carbide (SiC) inverter. This integrated filter may be smaller, lighter, and cheaper to construct than filters built from discrete components. An analytical model of the integrated dv/dt filter is developed, and this model is used to design output filters for a 460 V AC, three-phase SiC motor drive. Prototype filters are constructed and tested with a SiC inverter connected to a 460 Vrms, 30-HP induction motor, and experimental results demonstrate output waveforms that match the analytical model and meet the National Electrical Manufacturers Association (NEMA) MG 1 Part 31 requirements for inverter-rated motors. Finally, the voltage waveforms and losses of the prototype-integrated filter are compared with several other mitigation options, demonstrating that the integrated filters meet the NEMA specification at a fraction of the mass and volume of the discrete component solution without sacrificing efficiency.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Mission-Profile-Based System-Level Reliability Analysis in DC Microgrids
    • Authors: Saeed Peyghami;Huai Wang;Pooya Davari;Frede Blaabjerg;
      Pages: 5055 - 5067
      Abstract: Mission profiles such as environmental and operational conditions together with the system structure including energy resources, grid and converter topologies induce stress on different converters and thereby play a significant role on power electronic systems reliability. Temperature swing and maximum temperature are two of the critical stressors on the most failure-prone components of converters, i.e., capacitors and power semiconductors. Temperature-related stressors generate electrothermal stress on these components ultimately triggering high potential failure mechanisms. Failure of any component may cause converter outage and system shutdown. This paper explores the reliability performance of different converters operating in a power system and indicates the failure-prone converters from wear out perspective. It provides a system-level reliability insight for design, control, and operation of multiconverter system by extending the mission-profile-based reliability estimation approach. The analysis is provided for a dc microgrid due to the increasing interest that dc systems have been gaining in recent years; however, it can be applied for reliability studies in any multiconverter system. The outcomes can be worthwhile for maintenance and risk management as well as security assessment in modern power systems.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Microfabricated Magnetics on Silicon for Point of Load High-Frequency
           DC–DC Converter Applications
    • Authors: Dragan Dinulovic;Mahmoud Shousha;Martin Haug;Alexander Gerfer;Sebastian Beringer;Marc Christopher Wurz;Jef Thone;Mike Wens;
      Pages: 5068 - 5077
      Abstract: This paper presents the design, fabrication, and characterization on silicon integrated magnetics for high-frequency power applications. The presented device achieves superior characteristics in terms of energy density, electrical resistance, current capability, and inductance versus frequency stability. In order to demonstrate the effectiveness of use of the presented device for high-frequency power applications, it is tested with two different buck point of load (PoL) dc–dc converters, one of them is off-shelf chipset and the other is designed specifically for the microdevice. Experimental measurements show that the microdevices achieve a maximum inductance of about 50 nH, electrical resistance of 300 mΩ, rated current capabilities up to 1 A, and stable L versus f characteristics up to 100 MHz. Also, the PoL buck converters with the microdevices achieve a peak efficiency of up to 82% with a flat efficiency curve at switching frequencies up to 30 MHz while providing tight output voltage regulation (
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Novel Battery Management System Using the Duality of the Adaptive Droop
           Control Theory
    • Authors: Sifat M. Chowdhury;Mohamed O. Badawy;Yilmaz Sozer;J. Alexis De Abreu Garcia;
      Pages: 5078 - 5088
      Abstract: This paper proposes a new battery management system (BMS) for a series string of battery cells. The proposed control structure is based on the duality of the adaptive droop control theory used in dc micro-grid connected sources. An adaptive virtual admittance is used in this paper similar to the virtual resistance control structure used with dc micro-grid connected sources. The virtual admittance value is adjusted according to the associated state of charge for every connected battery cell. The presented BMS control structure yields higher reliability compared to the conventional ones due to its decentralization features and its communication-less ability. Thus, balanced power-sharing is realized among the connected battery cells during charging/discharging conditions. The stability of the proposed control is analyzed using the small signal model. The proposed BMS control structure is validated using simulation results and an experimental prototype for three connected battery cells.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Design Guidelines for the Perturb and Observe Technique for
           Electromagnetic Vibration Energy Harvesters Feeding Bridge Rectifiers
    • Authors: Luigi Costanzo;Alessandro Lo Schiavo;Massimo Vitelli;
      Pages: 5089 - 5098
      Abstract: The most widespread architecture of ac/dc converters for resonant electromagnetic vibration energy harvesters (REVEHs) is based on a diode bridge rectifier followed by a dc/dc converter. In order to maximize the power extraction from the harvester, the voltage at the output of the bridge rectifier must be regulated by a maximum power point tracking (MPPT) algorithm. This paper is focused on the optimization of the perturb and observe (P&O) MPPT technique for REVEHs. A complete set of general guidelines leading to the proper choice of the values of the two most important parameters of this MPPT technique is provided and experimentally validated. It is experimentally confirmed that if the P&O MPPT technique is not properly and carefully customized to the particular REVEH application of interest, it may lead to very poor performance of the system.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Hybrid Energy Storage Control in a Remote Military Microgrid With Improved
           Supercapacitor Utilization and Sensitivity Analysis
    • Authors: Giovanna Oriti;Norma Anglani;Alexander L. Julian;
      Pages: 5099 - 5108
      Abstract: This paper presents a novel power flow control system for a remote military microgrid with hybrid energy storage. A combination of batteries and supercapacitors (SCs) is managed by the novel control system to increase the battery life by redirecting the higher frequency current that would have to flow in the battery if SCs were not present. This paper offers a practical solution to manage the SC current and ensure that the SCs are never overcharged or commanded to support the system when they are discharged to the lower operating limit chosen. The new controller allows the independent selection of the low-pass filter parameter and the number of SCs. By making the most out of these two degrees of freedom, we investigate different configurations, identifying the one achieving the highest cash flow for the overall system. Modeling, simulations, and experimental verification are presented and linked to the sensitivity analysis of the economics of the military microgrid.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Two-Stage Fault Detection and Classification Scheme for Electrical Pitch
           Drives in Offshore Wind Farms Using Support Vector Machine
    • Authors: Surya Teja Kandukuri;Jagath Sri Lal Senanyaka;Van Khang Huynh;Kjell G. Robbersmyr;
      Pages: 5109 - 5118
      Abstract: Pitch systems are one of the components with the most frequent failure in wind turbines. This paper presents a two-stage fault detection and classification scheme for electric motor drives in wind turbine pitch systems. The presented approach is suitable for application in offshore wind farms with electric pitch systems driven by induction motors as well as permanent magnet synchronous motors. The adopted strategy utilizes three-phase motor current sensing at the pitch drives for fault detection and only when a fault condition is detected at this stage, features extracted from the current signals are transmitted to a support vector machine classifier located centrally to the wind farm. The proposed method is validated in an in-house setup of the pitch drive.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Supercapacitor to Provide Ancillary Services With Control Coordination
    • Authors: Jinho Kim;Vahan Gevorgian;Yusheng Luo;Manish Mohanpurkar;Vladimir Koritarov;Rob Hovsapian;Eduard Muljadi;
      Pages: 5119 - 5127
      Abstract: This paper proposes a dynamic frequency support scheme of a supercapacitor energy storage system (SCESS) in coordination with run-of-the-river-based pumped storage hydropower (PSH) to enhance the short-term frequency stability in a power system that has a high penetration of renewable energy. To achieve this, the proposed coordinated frequency controller (CFC) enables the SCESS and PSH plant to provide the frequency response. The CFC scheme employs a dynamic droop characteristic in parallel with an integral controller and a distribution function. The dynamic droop characteristic determines the power production for frequency regulation employing a variable gain, which varies with the total capacity of the frequency control units and magnitude of the system frequency error with time; the gain increases with the frequency error, and thereby, arresting the frequency nadir at a higher level than in the conventional droop characteristic. In addition, the distribution function dispatches the power from the dynamic droop and integral controller to the control units in proportion to their headrooms; furthermore, the distribution function considers a sudden loss of generation from an SCESS by its operational constraint during the frequency support. Thus, the proposed dynamic frequency support scheme can enhance the short-term frequency stability for a frequency event.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • IPOP-Connected FB-ZCS DC–DC Converter Modules for Renewable Energy
           Integration With Medium-Voltage DC Grids
    • Authors: Rohit Suryadevara;Tao Li;Kumar Modepalli;Leila Parsa;
      Pages: 5128 - 5140
      Abstract: This paper presents a dc–dc input-parallel output-parallel (IPOP) converter configuration for renewable energy integration with medium-voltage dc grids. A full-bridge zero-current-switching (FB-ZCS) converter with voltage-doubler output is proposed as the fundamental module. To achieve smooth current commutation and ZCS, the leakage inductance of transformer and a resonant capacitor across its secondary are utilized. This resonant capacitor is always charged to its full-rated capacity irrespective of converter loading and requires a dedicated charging interval resulting in duty-cycle loss. For a given leakage inductance, a large resonant capacitor is required for higher current ratings. With a single-centralized converter, these operational and design constraints result in significant duty-cycle loss, restricting the operation range. This paper proposes an IPOP configuration for high-power applications. Phase shedding at reduced loading ensures that individual modules are operated optimally. Input inductance requirement in modules is reduced due to interleaving of the input current. Additionally, voltage stress across converter components and input current ripple are reduced by 50% in the proposed converter modules. Steady-state operation, modeling, current-sharing control, start-up, and shutdown of modules in the IPOP configuration are demonstrated using simulations. Experimental results on a scaled-down prototype are presented to validate its operation.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Comparison of MPPT Strategies in Three-Phase Photovoltaic Inverters
           Applied for Harmonic Compensation
    • Authors: Victor Magno Rodrigues de Jesus;Allan Fagner Cupertino;Lucas Santana Xavier;Heverton Augusto Pereira;Victor Flores Mendes;
      Pages: 5141 - 5152
      Abstract: The main objective of a photovoltaic (PV) inverter is to inject the PV power into the ac grid. Generally, due to variations in solar irradiance, inverters operate below their rated current. Therefore, this current margin can be used to perform ancillary services, such as reactive power control and harmonic current compensation. However, it is necessary to evaluate the effects of these ancillary services on the converter. The harmonic current compensation, for example, affects the efficiency of the maximum power point tracking (MPPT) algorithms. Therefore, this paper presents a mathematical modeling that relates the harmonic current compensation with the oscillation in the dc-link capacitor voltage, validated through simulation and experimental results. Simulation results show the instantaneous and dynamic efficiency of MPPT algorithms during rapidly irradiance variations and harmonic current compensation. The results lead to the conclusion that all MPPT strategies tested have faced degradation in efficiency due to harmonic current compensation.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Grid Interactive Solar PV-Based Water Pumping Using BLDC Motor Drive
    • Authors: Rajan Kumar;Bhim Singh;
      Pages: 5153 - 5165
      Abstract: This paper proposes bidirectional power flow control of a grid interactive solar photovoltaic (PV)-fed water pumping system. A brushless DC (BLDC) motor drive without phase current sensors is used to run a water pump. This system enables a consumer to operate the water pump at its full capacity for 24 hours regardless of the climatic condition and to feed a single-phase utility grid when water pumping is not required. The full utilization of a PV array and motor pump is made possible in addition to an enhanced reliability of the pumping system. A single-phase voltage source converter with a unit vector template generation technique accomplishes a bidirectional power flow control between the grid and the dc bus of the voltage source inverter (VSI), which feeds a BLDC motor. The VSI is operated at fundamental frequency, which minimizes the switching loss. The maximum power point operation of a PV array, and power quality improvements, such as power factor correction and reduction of total harmonic distortion of grid, are achieved in this system. Its applicability and reliability are demonstrated by various simulated results using MATLAB/Simulink platform and hardware implementation.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Hybrid Modular Multilevel Converter for Solar Power Integration
    • Authors: Tuhin S. Basu;Suman Maiti;
      Pages: 5166 - 5177
      Abstract: A hybrid modular multilevel converter (H-MMC) for grid-connected photovoltaic (PV) system is presented in this paper. The array of PV panels is connected in each submodule of the converter. The submodules are connected in series to form the dc link for each phase. The dc-link voltage is unipolar and multilevel in nature, which is converted to ac voltage by a low frequency converter. This topology can be applicable at high power by increasing number of submodules per phase. The H-MMC has many advantages compared to conventional MMC, e.g., more voltage levels, less capacitor count, no circulating current, higher efficiency, and less foot print. A global maximum power point tracking (MPPT) algorithm is proposed for this converter, which requires the voltage and current signals of only one submodule. The limitations of global MPPT under partial shading are overcome through distributed MPPT. A least-MPPT algorithm is presented to make the three phase powers balanced under nonuniform partial shading among the phases. The usefulness of this converter configuration with two different MPPT algorithms (global and distributed) is investigated through PSCAD/EMTDC simulation. A single-phase version of the converter with global and distributed MPPT is experimentally validated considering partial shading condition. The results show the usefulness of H-MMC and associated control for PV integration.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Frequency Support Properties of the Synchronous Power Control for
           Grid-Connected Converters
    • Authors: Weiyi Zhang;Andrés Tarraso;Joan Rocabert;Alvaro Luna;J. Ignacio Candela;Pedro Rodriguez;
      Pages: 5178 - 5189
      Abstract: Grid-connected power converters that integrate frequency support and inertia emulation functionalities have emerged in the last years. These features are promising for renewable energy-based power generation plants, as it permits such systems to contribute to enhance the power system stability. This paper discusses about three different active power control solutions that can be applied to grid-connected converters equipped with a synchronous power controller. For each solution, the detailed analytical relationship between the control parameters and the power loop dynamics is illustrated, and the local stability and dynamics are analyzed. The analysis and validation of frequency support functionalities are particularly addressed in this study, where the results obtained in a 10-kW experiment endorse the analysis; finally permitting to conclude that the synchronous power control offers good performance in terms of inertial response and droop characteristics.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Power Quality Improved EV Charger With Bridgeless Cuk Converter
    • Authors: Radha Kushwaha;Bhim Singh;
      Pages: 5190 - 5203
      Abstract: An improved bridgeless (BL) Cuk converter-based electric vehicle (EV) battery charger with high power factor and increased efficiency is designed and developed in this paper. It provides low cost and high-power-density-based charging solution for the EV. This charger incorporates less number of devices operating over one switching cycle, which reduces the additional conduction loss incurred by a diode bridge rectifier of the conventional charger. Hence, it improves the charger's efficiency. The added advantage of the proposed topology is that the unwanted capacitive coupling loop is removed, as well as the unwanted conduction through the body diode of the inactive switch in the previously developed BL Cuk converter is avoided. This significantly improves the charger's efficiency. For the constant current and constant voltage charging, the commands are synchronized by a flyback converter. The proposed charger draws a sinusoidal current from ac mains and the total harmonic distortion in the supply current is reduced to the limits specified by the IEC 61000-3-2 guidelines. The improved efficiency and power quality indices of the proposed charger are investigated to demonstrate its satisfactory charging operation at all operating conditions.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Demagnetization Analysis of Interior Permanent Magnet Machines Under
           Integrated Charging Operation
    • Authors: Wenlong Li;Guodong Feng;Chunyan Lai;Ze Li;Jiangbo Tian;Narayan C. Kar;
      Pages: 5204 - 5213
      Abstract: Integrated battery charging (IBC)—multiplexing the motor windings as line inductors for charging electric vehicle battery packs—can improve the onboard charging capability without increasing the weight and cost. However, during the charging operation, currents flowing in the stator winding definitely generate a magnetic field, which may demagnetize the permanent magnets (PMs) in the PM traction motors. In this paper, the demagnetization effects of IBC current on magnets in interior PM machines are compressively investigated. In this paper, a recursive algorithm to update the PM magnetization states by using a parallelogram hysteresis model at different demagnetization levels is applied. The PM temperature is also considered for establishing this model. By coupling this algorithm to the finite element analysis, the demagnetization transit at different demagnetization levels can be assessed. By decomposing the flux density of each node within the magnets along its magnetization direction, irreversible demagnetization can be accurately evaluated. Impacts from both the pulsating and rotating demagnetization magnetic fields during the IBC operation are assessed and compared.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Multi-Domain Design Optimization of dv/dt Filter for SiC-Based Three-Phase
           Inverters in High-Frequency Motor-Drive Applications
    • Authors: Jiangbiao He;Cong Li;Anoop Jassal;Naveenan Thiagarajan;Yichao Zhang;Satish Prabhakaran;Carlos Feliz;James E. Graham;Xiaosong Kang;
      Pages: 5214 - 5222
      Abstract: High slew rate of the line voltage $(boldsymbol {dv}/boldsymbol {dt})$ has been a concern for power inverters based on the emerging wide bandgap switching devices, such as silicon carbide (SiC) mosfets. Particularly, for SiC-based power inverters feeding electric machines interconnected with long cables, there could be more severe insulation stress on the stator windings in electric machines, due to the higher dv/dt output from the SiC inverters. Compared to the conventional lower voltage electric transportation applications (e.g., 270 V dc), higher dc bus voltage of 500–600 V can dramatically reduce cable weight and systematic copper losses, hence improve the power density and efficiency of power converters. However, high dc bus voltage further increases the $boldsymbol {dv}/boldsymbol {dt}$ level in the converter ac line voltages. Driven by the necessity of developing SiC inverters with 500 V dc bus in electric transportation applications while attenuating the $boldsymbol {dv}/boldsymbol {dt}$ stress to a low level, this paper presents a multi-domain design approach for dv/dt filters that comprehensively considers the constraints in electrical, magnetic, and thermal domains. Experimental results based on a 75 kW SiC inverter are provided to verify the efficacy of this design approach.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Vehicular Integration of Wireless Power Transfer Systems and Hardware
           Interoperability Case Studies
    • Authors: Omer C. Onar;Madhu Chinthavali;Steven L. Campbell;Larry E. Seiber;Cliff P. White;
      Pages: 5223 - 5234
      Abstract: Several wireless charging methods are under development or available as an aftermarket option in the light-duty automotive market. However, there are not a sufficient number of studies detailing the vehicle integration methods, particularly a complete vehicle integration with higher power levels. This paper presents the design, development, implementation, and vehicle integration of wireless power transfer (WPT) based electric vehicle charging systems for various test vehicles. Before having the standards effective, it is expected that WPT technology first will be integrated as an aftermarket retrofitting approach. Inclusion of this technology on production vehicles is contingent upon the release of the international standards. The power stages of the system are introduced with the design specifications and control systems, including the active front-end rectifier with power factor correction, high frequency power inverter, high frequency isolation transformer, coupling coils, vehicle side full-bridge rectifier and filter, and the vehicle battery. The operating principles of the control and communication systems are presented. Aftermarket conversion approaches, including the WPT on-board charger integration, WPT CHAdeMO integration, and WPT direct battery connection scenarios, are described. The experiments are carried out using the integrated vehicles and the results obtained to demonstrate the system performance including the stage-by-stage efficiencies.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Flow Electrification in Turbulent Flows of Liquids—Comparison of Two
           Models for One Specific Case
    • Authors: Juan-Martin Cabaleiro;Thierry Paillat;Guillermo Artana;Gerard Touchard;
      Pages: 5235 - 5238
      Abstract: This paper deals with flow electrification phenomenon for turbulent flows of liquids through pipes of a circular cross section. Two models are proposed. The first one is based on the comparison of the radial fluctuant velocity magnitude with the magnitude of the diffuse layer relaxation velocity: it assumes that in the region where the fluctuant velocity is greater than the relaxation velocity the diffuse layer is totally perturbed so that the charge is homogenized by the turbulence, whereas when the relaxation velocity is greater than the fluctuant velocity the diffuse layer is considered not perturbed at all. The charge transported by the flow is then calculated with this new charge profile. The second model consists in solving the system of the diffuse layer equations perturbed by the turbulence, taking into account the eddy diffusivity; then with the profile of the charge obtained in the cross section the charge transported is calculated. Finally, the predictions of the charge transported using each model are compared in a specific case and discussed [1].
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Electrospinning Polymer Nanofibers With Controlled Diameters
    • Authors: Suqi Liu;Kevin L. White;Darrell H. Reneker;
      Pages: 5239 - 5243
      Abstract: Rapidly growing needs for large-scale industrial production of polymer nanofibers produced by electrospinning require better control of electrospinning. In this paper, the capability of electrospinning polymer nanofibers with desired diameter and morphology was demonstrated. Concentration of the polymer solution, together with electrical conductivity and surface tension of the polymer solution, were adjusted to control the diameter and morphology of electrospun nanofiber. Nanofibers of polyacrylonitrile and polyvinylidene fluoride were successfully electrospun, with average diameters in the range from 100 to 400 nm. Real-time optical and electrical observations of electrospinning phenomena and adjustments of experimental variables in an electrospinning process contribute to a feedback system for online controlled electrospinning, which requires a multidisciplinary approach including chemistry, electrical engineering, and material science.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Modeling and Simulation of Nonconductive Particles Trajectories in a
           Multifunctional Electrostatic Separator
    • Authors: Mohamed Maammar;Wessim Aksa;Mohamed Fodil Boukhoulda;Seddik Touhami;Lucian Dascalescu;Thami Zeghloul;
      Pages: 5244 - 5252
      Abstract: Electrostatic separation is a technique based on the electric field forces acting on small charged or polarized particles. Several electrostatic machines have been developed over past decades, operating with different principles and treating various mixture types. The multifunctional electrostatic separator is one of the most efficient installations for the treatment of micronized materials. This paper aims to numerically simulate the dynamic behavior of micronized insulating particles in this type of separator. The numerical model of the electrostatic field calculated by COMSOL is used in a MATLAB program to simulate particle trajectories under the effect of electrical and mechanical forces. The numerical simulation implemented takes into account the impact of the particles with the rotating electrode. The intensity and direction of the forces exerted on the particles in the high-intensity electric field area determine their behavior, and thus, the quality of the separation.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Control Charts for Statistical Process Control of the Tribocharging of
           Polymer Slabs in Frictional Sliding Contact
    • Authors: Yopa Eka Prawatya;Khouira Senouci;Thami Zeghloul;Marian Bogdan Neagoe;Lucian Dascalescu;Karim Medles;
      Pages: 5253 - 5260
      Abstract: Besides the nature and condition of the surfaces in contact, several factors influence the triboelectric charging of polymer slabs in frictional sliding contact: pressure load and relative velocity between the two bodies, number of friction cycles, ambient temperature, and humidity. This paper is aimed at pointing out the peculiarities of the statistic control of such a process. Thirty experiments were performed for the optimal combination of factor values (i.e., normal force: 10 N; sliding speed: 55 mm/s; number of sliding cycles: 10) that maximize the absolute value of the average potential at the surface of the tribocharged materials: 1600 V. The capability index calculated from the experimental data was satisfactory and two Shewart charts were established for the statistical control of the process. Two out-of-control situations were simulated, in order to test the efficiency of the charts.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Aftertreatment of Carbon Particles Emitted by Diesel Engine Using a
           Combination of Corona and Dielectric Barrier Discharge
    • Authors: Keiichiro Yoshida;
      Pages: 5261 - 5268
      Abstract: The collection and incineration mechanisms in the particulate matter (PM) aftertreatment technique proposed by the author were investigated. An experiment for actual exhaust gas was performed by sampling 10 NL/min of exhaust gas from the flue gas from a stationary diesel engine generator. The reactor for PM aftertreatment comprised a glass tube with surrounding corona needles that projected negative charges. Various combinations of voltages applied to each of the corona needles and the surface electrodes were compared. The results enhanced the hypothesis that negatively charged PM is attracted by the dielectric surface that is positively charged by positive ions supplied by the electrode on the glass surface. Subsequently, conditions for carbon incineration by nonthermal plasma were investigated using a simulated dielectric barrier discharge electrode and carbon black particles applied to the surface. It was found that the gap length over which the carbon-adhered area and the surface electrode face each other is the key factor for the rate of incineration.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Impact of Icing Severity on Positive Corona Generated Audible Noise
           Characteristic of Rime Ice-Covered Conductor
    • Authors: Gaohui He;Qin Hu;Lichun Shu;Xingliang Jiang;Hang Yang;Dachuan Yang;Raji Sundararajan;
      Pages: 5269 - 5276
      Abstract: This research studies the impact of icing severity on audible noise (AN) characteristics of a rime ice-covered smooth conductor. The conductor is energized with positive polarity voltage during artificial icing experiment and corona performance experiment. The experiments are performed in a corona cage located in an artificial climate chamber. Test results show that harsher icing severity causes higher AN and the AN approaches saturation. The empirical formula for different icing severities is also given, which can help predict the AN, once the icing thickness and nominal electric field intensity are given. The studies of the one-third octave band spectra indicate that the audio frequency can be divided into three sections: background noise section, transitional section, and corona discharge section. The A-weighted AN is independent of the frequency components in the background noise section. However, in the corona discharge section, the differences between A-weighted AN and frequency components are constant once the frequency component is designated. Especially, the 3.15-kHz component is recommended to extract the corona-generated AN during the long-term AN monitoring, and its relative error is less than 3.6%.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Synchronization Control Technique For Soft Connection of Doubly Fed
           Induction Generator Based Wind Turbines to the Power Grids
    • Authors: Abilash Thakallapelli;Sukumar Kamalasadan;Kashem M. Muttaqi;Mehrdad T. Hagh;
      Pages: 5277 - 5288
      Abstract: Doubly-fed induction generator (DFIG)-based wind turbine generators need to be connected back to integrated power grid after tripping due to disturbances and emergencies in power grid. Re-connection can cause switching transients which may affect overall grid stability. This situation can be avoided if proper synchronization can be ensured for smooth transition of DFIG from island mode to grid-connected mode. To this effect, in this paper, a direct voltage control based synchronization method is introduced that can ensure low or no transient effect during synchronization of DFIG to the grid. The controller is synthesized based on a multi-channel identification methodology and integrated using a designed grid connection logic for soft synchronization. The architecture is implemented on a modified IEEE 39 bus system with DFIG and tested on a real-time simulation platform with different wind speed conditions. It is observed that the proposed architecture makes the grid more stable (with swings in voltage or frequency reduced as much as 60%) during re-connection of wind generators.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Dual Operation Mode of a Transformerless H-Bridge Inverter in Low-Voltage
           Microgrid
    • Authors: Qusay Salem;Libo Liu;Jian Xie;
      Pages: 5289 - 5299
      Abstract: This paper presents the bilateral operation of a transformer-less H-bridge inverter as a power flow controller and fault current limiter in low-voltage distribution network. A novel control strategy has been developed to initiate and activate the H-bridge inverter to control the power flow at point of common coupling (PCC). On the other hand, the H-bridge inverter operation like a short-circuit current limiter during grid disturbance event and its smooth reinsertion after fault clearance have also been clarified. Besides, an island mode control strategy incorporating synchronization controller, and proper coordination with flip flops have been implemented in order to synchronize the microgrid with the main grid before reclosing the circuit breaker. The results confirm: The effectiveness and feasibility of the novel control methodology in activating the real power flow; the inverter capability of minimizing the short-circuit current during fault and the successful resynchronization of the microgrid voltage source inverter (VSI) and the H-bridge inverter to the main grid.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • FPGA-Based Device-Level Electro-Thermal Modeling of Floating Interleaved
           Boost Converter for Fuel Cell Hardware-in-the-Loop Applications
    • Authors: Hao Bai;Chen Liu;Shengrong Zhuo;Rui Ma;Damien Paire;Fei Gao;
      Pages: 5300 - 5310
      Abstract: Floating interleaved boost converter (FIBC) is a promising topology of the dc/dc converters to interface the fuel cell with dc bus in a hybrid powertrain. For the efficient control development of power converters, the hardware-in-the-loop (HIL) simulation plays an important role. The accuracy of the real-time model determines the credibility of the HIL simulation. In order to take the power losses and thermal stress into account in the control development, the device-level real-time model is becoming popular in recent years, which can effectively produce device transient voltage and current waveforms, switching power dissipations, and thermal behaviors. In this paper, a device-level electro-thermal model of FIBC is proposed and developed using the field programmable gate array based real-time simulation technology. The FIBC network model can effectively be simulated with a 500-ns time step while producing the insulated-gate bipolar transistor transient switching waveforms authentically with a 5-ns resolution. The switching power losses can thus be estimated in real time and then used for the computation of the IGBT thermal behavior. Therefore, the device junction temperature can be evaluated in the real-time simulation. The accuracy of the proposed FIBC device-level model is validated by the reference model in the Saber offline simulation tool. At last, an embedded PI controller of FIBC is employed in the real-time experiments to verify the effectiveness of the developed model.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Stochastic Predictive Control of Multi-Microgrid Systems
    • Authors: Najmeh Bazmohammadi;Ahmadreza Tahsiri;Amjad Anvari-Moghaddam;Josep M. Guerrero;
      Pages: 5311 - 5319
      Abstract: In this paper, integrated operation management of cooperative microgrids is formulated in the framework of stochastic predictive control. In the proposed scheme, a joint probabilistic constraint on the microgrids power exchange with the main grid couples operation of individual microgrids. In order to tackle the coupling constraint, a cooperative energy management strategy is proposed in which based on the statistical characteristics of uncertain parameters, the deterministic counterpart of the problem is derived and an efficient solution strategy is achieved. The proposed strategy is evaluated for an illustrative test case including two microgrids based on modified CIGRE benchmark. Moreover, statistical analysis is conducted to evaluate robustness characteristics of the solution strategy.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Operational Value-Based Energy Storage Management for Photovoltaic (PV)
           Integrated Active Power Distribution Systems
    • Authors: Sheikh Jakir Hossain;Biswajit Dipan Biswas;Rojan Bhattarai;Muhammad Ahmed;Sherif Abdelrazek;Sukumar Kamalasadan;
      Pages: 5320 - 5330
      Abstract: This paper presents an operational cost-based approach for battery energy storage management. In this approach, the operation value is derived to optimally manage one battery application—photovoltaic (PV) capacity firming or PV smoothing. The proposed approach is an optimization framework that augments a PV smoothing algorithm where the battery is used to smooth the output of intermittent PV farm. The objective of the optimization framework is to provide maximum operational benefits for the battery. To this end, first, a formal method is developed that finds the operational benefits which is then demonstrated using a field verified electro-magnetic transient (EMTP) model of a real-world feeder. Second, the positive effect in the operation of the feeder is quantified in terms of monetary value. It is demonstrated that the knowledge of monetary value can provide better operational benefits of energy storage applications such as PV smoothing.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Hardware-in-the-Loop Realization of Speed Sensorless Control of
           PMa-SynRM With Steady-State and Transient Performances Enhancement
    • Authors: Mahmoud Amin;Ghada A. Abdel Aziz;James Durkin;Osama A. Mohammed;
      Pages: 5331 - 5342
      Abstract: This paper presents the design and implementation of a novel low-cost speed sensorless control technique for a permanent magnet assisted synchronous reluctance motor (PMa-SynRM). A robust adaptive speed (RAS) observer is designed for estimating the rotor speed and position, respectively. The RAS observer estimates the PMa-SynRM speed and position from the back electromotive force space-vector determination without voltage sensors by using the reference voltages issued from the current controllers instead of the actual ones. The novelty of the proposed RAS estimation technique is the adaptation of the feedback error of the actual values. Thus, the proposed observer structure promises a higher degree of robustness against PMa-SynRM parameter changes in the sensitivity analysis presented in this paper. The dynamic model and experimental realizations of the proposed control technique are introduced. A 6-kW PMa-SynRM drive test setup is constructed including a dSPACE 1104 board as the control heart of the proposed system. The hardware-in-the-loop Typhoon HIL 402 device is used to experimentally emulate the PMa-SynRM and the inverter connected to a dSPACE MicroLabBox. The proposed RAS observer robustness is evaluated using a HIL model and experimental results under different conditions. A comparative experimental analysis between the proposed RAS and Luenberger observers has been performed.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Robust Nonlinear Adaptive Feedback Linearizing Decentralized Controller
           Design for Islanded DC Microgrids
    • Authors: Md Apel Mahmud;Tushar Kanti Roy;Sajeeb Saha;M. Enamul Haque;Hemanshu R. Pota;
      Pages: 5343 - 5352
      Abstract: This paper presents a robust nonlinear decentralized control scheme for islanded dc microgrids, where the main control objectives are to achieve the desired voltage at the common dc bus and to maintain the power balance. The proposed control scheme uses the partial feedback linearization scheme to simplify the dynamical models of different components in dc microgrids. In this paper, the dc microgrid includes a solar photovoltaic unit, a fuel cell system, and a battery energy storage system along with dc loads. The robustness of the proposed controller against parametric uncertainties is ensured by the parameter, appearing in the control inputs as unknown, which is then estimated through adaptation laws. The inherent noise decoupling capability of the feedback linearization scheme is used to provide robustness against external disturbances in dc microgrids. The performance of the proposed controller is evaluated on a dc microgrid through simulation and experimental studies in order to demonstrate the effectiveness and robustness under different operating conditions, while considering the effects of parametric uncertainties and external disturbances. Simulation results are also compared with an existing proportional-integral controller.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • $H_2$ +Performance*&rft.title=Industry+Applications,+IEEE+Transactions+on&rft.issn=0093-9994&rft.date=2019&rft.volume=55&rft.spage=5353&rft.epage=5359&rft.aulast=Körösi;&rft.aufirst=Vojtech&rft.au=Vojtech+Veselý;Ladislav+Körösi;">Robust PI-D Controller Design for Uncertain Linear Polytopic Systems Using
           LMI Regions and $H_2$ Performance*
    • Authors: Vojtech Veselý;Ladislav Körösi;
      Pages: 5353 - 5359
      Abstract: The paper deals with the new design procedure for PID-D robust controller with state/output derivative feedback to stabilize the closed-loop system using linear matrix inequality (LMI) and LMI regions with common in the frame of $H_2$ performance quadratic cost functions known as $(Q,S,R)$. The designed robust controller ensures robust properties of the closed loop system for linear time invariant and linear time variant gain scheduled plant descriptor systems. The robust controller design procedure is based on the extended original derivative of Lyapunov function and to obtain the convex conditions with respect to uncertainties, gain scheduled variables, and ensures that proposed new method guarantees less conservativeness to the design procedure we have introduced using the auxiliary matrices. The obtained results should be utilized to design power system stabilizer for synchronous generators and so on. The obtained robust PI-D controller with output and state/output derivative feedback for uncertain polytopic systems ensures that all closed-loop eigenvalues are lying in the defined LMI region. Two examples illustrate the effectiveness of the new design procedure.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Coupled Inductor-Based Zero Current Switching Hybrid DC Circuit Breaker
           Topologies
    • Authors: Anindya Ray;Kaushik Rajashekara;Satish Naik Banavath;Sumit Kumar Pramanick;
      Pages: 5360 - 5370
      Abstract: This paper proposes a coupled inductor-based hybrid dc circuit breaker topology with zero current switching for fast fault interruption in dc systems. A series resonant circuit comprising of the secondary winding of a two-winding coupled inductor and a charged capacitor (commutation capacitor) is switched on during fault to inject a counter-current pulse, and, consequently, force a zero crossing of fault current. Proposed solution facilitates arcless breaking for a mechanical circuit breaker due to zero current turn-off. The proposed circuit breaker exhibits fast fault response ($sim$30 $mu$s), and the response time is programmable based on the design of the coupled inductor and commutation capacitor. Furthermore, presented solution mitigates the requirement of energy-absorbing elements for demagnetizing the dc network following fault interruption, in contrast to conventional dc breakers. The paper also presents two modified circuit-breaker topologies to achieve unipolar voltage profile on the capacitor, which will enable the use of electrolytic capacitors for commutation so that the capacitor stack size is reduced in high-voltage applications. Detailed analysis and design equations are presented to explain the operation of the proposed topologies. Functionality of the proposed circuit breakers is verified through simulation, and experimental results are based on two laboratory prototypes.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Understanding the Staircase Modulation Strategy and Its Application in
           Both Isolated and Grid-Connected Asymmetric Cascaded H-Bridge Multilevel
           Inverters
    • Authors: Tiago Davi Curi Busarello;Andre Luiz de Sousa Marcondes Reuter;Adriano Péres;Marcelo Godoy Simões;
      Pages: 5371 - 5382
      Abstract: The staircase modulation strategy is the best choice for asymmetric cascaded H-bridge multilevel inverter (ACMI) because it makes the output voltage to present a high number of levels and makes one of the ACMI modules to operate at low frequency. However, the staircase modulation is usually employed without giving its deserved attention. This paper presents a clear understanding of the staircase modulation strategy and its applications in both isolated and grid-connected ACMI.  The main novelty of this paper is the obtaining of the switching function for each module. The principle of operation is carefully described, also indicating how to command the ACMI transistors. The output voltage of the two superior modules is evaluated for different values of iterations. Special attention is given to the power distribution among the ACMI modules when the staircase modulation is applied. It is demonstrated on how the power is processed in each module considering an ACMI with three modules. The analysis is presented showing the staircase modulation within a closed-loop control strategy for isolated and grid-connected modes of operation, showing that the content of this paper is valid for both modes. Experimental results clarify and show the efficacy of the content presented in this paper.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Recursive Implementation of Multiple Delayed Signal Cancellation Operators
           and Their Applications in Prefiltered and In-Loop Filtered PLLs Under
           Adverse Grid Conditions
    • Authors: Srinivas Gude;Chia-Chi Chu;Sastry V. Vedula;
      Pages: 5383 - 5394
      Abstract: Phase-locked loops (PLLs) are widely utilized for grid synchronization and control of power electronic converters. More recently, both in-loop-filtered- and prefiltered-based PLLs have become more popular due to their prompt and accurate estimations of grid voltage quantities. In the past, an advanced filter viz., multiple delayed signal cancellation (MDSC) operators, has been successfully investigated in both $alpha beta$-frame and $dq$-frame for extracting fundamental-frequency positive-sequence grid voltage quantities by using conventional synchronous reference frame PLL. These operators can provide more flexibility to configure the delay time and undesired harmonics in comparison with the existing cascaded delayed signal cancellation operators. In this paper, the recursive-form structures of MDSC operators are analyzed, which are derived from the direct-form MDSC realizations. The recursive-form structures of MDSC operators are simple in implementation when compared to direct-form realizations. With the recursive-form MDSC implementations, both prefiltered MDSC-PLL and in-loop filtered MDSC-PLL will be investigated in detail. The design guidelines of these recursive-form-based MDSC-PLLs are presented. Comparison studies of the proposed PLLs and the validation of their dynamic performances are done by experimental verifications.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Assessing the Performance of ROCOF Relay for Anti-Islanding Protection of
           Distributed Generation Under Subcritical Region of Power Imbalance
    • Authors: Mollah Rezaul Alam;Most. Tasneem Ara Begum;Kashem M. Muttaqi;
      Pages: 5395 - 5405
      Abstract: In practice, the load-curve and distributed generation (DG) penetration level determines the power imbalance level that a network can experience if islanding occurs. Therefore, with the prior knowledge of load-curve and DG penetration level, the setpoint of rate-of-change-of-frequency (ROCOF) relays can be adjusted so as to make them suitable for a real network. This paper first investigates the subcritical power imbalance region of ROCOF relays through analytical formulation followed by extensive simulation study in order to establish the maximum boundary limit of ROCOF's nondetection zone (NDZ) under all possible deficit/excess of active and/or reactive power imbalance scenarios. Second, ROCOF's reliability (assessed by detection rate and false alarm rate) is expressed analytically and then, validated numerically by simulating a test network of Australia in MATLAB and OPAL-RT real-time digital simulation platform. Finally, ROCOF's performance is assessed through receiver operating characteristics curves and a detailed reliability study under variable setpoints and detection time of the relays; the assessment considers the number of islanding events associated with the time-wise percentage of power imbalance level computed from the net load demand and variable DG penetration in a real network. All these test results demonstrate a clear operational guideline for ROCOF relay.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Extended Range of Ultra Sparse Matrix Converter Using Integrated Switched
           Capacitor Network
    • Authors: M. Raghuram;Avneet K. Chauhan;Santosh Kumar Singh;
      Pages: 5406 - 5415
      Abstract: Ultra sparse matrix converter (USMC) is known for ac–ac conversion with sinusoidal input currents, output voltages, and variable frequency operation. However, its operation is restricted for voltage gain up to 0.866 and load power factor angle up to $30^circ$ along with requirement of protection circuit for pulsating loads. This paper proposes switched capacitor USMC to overcome the restrictions of USMC with improved performance. Experimental results are provided to evaluate the converter capability and behavior under balanced and unbalanced input voltage conditions. Furthermore, the proposed converter is compared with the other counterparts.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Comprehensive Controller Implementation for Wind-PV-Diesel Based
           Standalone Microgrid
    • Authors: Miloud Rezkallah;Sanjeev Singh;Ambrish Chandra;Bhim Singh;Marco Tremblay;Maarouf Saad;Hua Geng;
      Pages: 5416 - 5428
      Abstract: In this paper, a comprehensive controller of a standalone microgrid is implemented, which has three dispersed generation units based on a wind, solar photovoltaic (PV) array, and a diesel generator (DG). The power ratio variable step perturb and observe method is applied to achieve maximum power point tracking of a solar PV array and a variable speed wind turbine coupled a permanent magnet brushless dc generator without rotor/wind speed sensors. Moreover, to ensure perfect synchronization of a DG to the point of common coupling (PCC), a control algorithm is developed, which is based on in-phase and quadrature units. An active power control based on proportional–integral controller with anti-windup, is used for voltage and frequency regulation. The LCL filter based on virtual resistor, is used for power quality improvement at PCC. Simulation and test results are presented for the validation of the proposed system using a prototype of 2 kW in the laboratory.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • External Electrode Fluorescent Lamp (EEFL) Driving Methods
    • Authors: Walter Kaiser;Ricardo Paulino Marques;
      Pages: 5429 - 5435
      Abstract: External electrode fluorescent lamps (EEFLs) are used as backlight source for large screen size liquid-crystal displays. Since electrodes are outside of the discharge tube, lifetime is enhanced when compared with cold cathode fluorescent lamps. Also, a single inverter can drive multiple EEFL tubes, leading to a compact design, driven by sinusoidal or square waveforms. Luminance can be enhanced by synchronizing the moment of the self-discharge of the dielectric wall charge with voltage rising and falling. This paper presents luminance measurements for different driving alternatives and lamp voltages, showing that EEFLs have an electrical behavior similar to dielectric barrier discharge lamps and light emission similar to the conventional fluorescent lamps. It is also shown that sinusoidal operation is more efficient than square wave operation in the light emission sense for the explored conditions.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Investigation of LED Lighting Performance in the Presence of Ripple
           Injection Load Control Signals
    • Authors: Obaidur Rahman;Sean Elphick;Kashem M. Muttaqi;Jason David;
      Pages: 5436 - 5444
      Abstract: This paper presents the outcomes of laboratory evaluation of the performance of a sample of LED lighting systems (lamp/driver and dimmer combinations) in presence of audio frequency injection control (AFIC) signals used by electricity distribution system network service providers (DNSPs) for control of certain loads. The testing presented in this study has been undertaken in response to a significant number of customer complaints that have been received by DNSPs related to the performance of LED lighting systems with dimmers incorporated. In a number of cases, performance issues have been verified in the field to occur during periods where AFIC signaling voltages are present in the electricity distribution network. In order to determine the contributing factors that AFIC signaling may have on the performance of the LED lighting system, a light-based flicker evaluation testing system has been developed to investigate LED lighting system performance under controlled conditions. One of the main objectives of the study was to use light-based flicker indices to identify the effect on different combinations of LED lamps/drivers and dimmers by varying the voltage magnitude and frequency of the AFIC signal as well as the position (i.e., voltage output) of the dimmer. Visual observations were also carried out to investigate the correlation between measured flicker indices and visually observed flicker. This paper presents the test results that have been analyzed in terms of types of technologies used in LED lamp/driver and the variables in the AFIC signal.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A High-Frequency High Voltage Gain DCM Coupled-Inductor Boost LED Driver
           Based on Planar Component
    • Authors: Shanshan Gao;Yijie Wang;Yueshi Guan;Dianguo Xu;
      Pages: 5445 - 5454
      Abstract: A high-frequency high voltage gain discontinuous conduction mode coupled-inductor boost LED driver based on planar component is presented in this paper. GaN switch is adopted with lower conducting resistance and higher switching speed. Zero voltage switching (ZVS) is achieved at the same time to reduce high switching loss caused by high switching frequency. Compared with the previous work, the voltage gain is higher and efficiency is higher because of ZVS. This paper focuses on high efficiency; therefore, resonant gate driver is adopted and efficiency is increased by 0.6%. In terms of the coupled-inductor, planar component is used and parameter optimization is also proposed to realize lower loss, including wingding loss and fringing loss caused by the air gap. A 500 kHz 36 W prototype has been designed to demonstrate theoretical analysis. In addition, comparison of drive loss between the resonant gate driver used in this paper and conventional driver implemented by Si8271 is made, revealing advantages of the resonant driver. Obtained efficiency was up to 92.1% at full load.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • A Remotely Central Dimming System for a Large-Scale LED Lighting Network
           Providing High Quality Voltage and Current
    • Authors: Radwa Mohamed Abdalaal;Carl Ngai Man Ho;Carson K. Leung;Henry Shu-Hung Chung;
      Pages: 5455 - 5465
      Abstract: Standard TRIAC-based dimmers introduce power quality issues especially for a large-scale lighting network. Other existing dimming protocols involve additional wiring systems and/or additional controllers to light emitting diode (LED) drivers. This paper proposes a central dimming system for a large penetration of LED lamps. The dimming system is remotely controlled through a webpage or a desktop application. Dimming is achieved while maintaining high voltage and current quality waveforms, which results in a high power factor and a low input current harmonic distortion. The system does not require additional wiring or specific adjustments to commercial dimmable LED drivers. The system allows scheduling a dimming profile to endorse energy saving. In the proposed dimming system, dimming function is achieved by connecting a voltage source converter (VSC) between the grid and the LED lamps. An advanced feature is added to the VSC dimmer to remotely send/receive messages between the system and the user through a graphical user interface. Thus, the user can communicate with the VSC dimmer by sending commands and receiving feedback information. The influence of communication delay on system stability is analyzed by using small signal models. A VSC dimmer prototype (500 VA/120 V) has been built with a communication module to provide remote control. Experimental results and comparisons between utilizing the TRIAC-based dimmer and the VSC dimmer for dimming function are discussed in the paper.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Profile Measurement of Rails in a Rolling Mill: Implementing and
           Evaluating Autonomic Computing Capabilities
    • Authors: Álvaro F. Millara;Julio Molleda;Rubén Usamentiaga;Daniel F. García;
      Pages: 5466 - 5475
      Abstract: Profile measuring is a key data acquisition process in the rail manufacturing industry. In rail rolling mills, profile measurement systems inspect the shape of the rail profiles to assess their dimensional quality. This assessment can be used in order to provide feedback for shape control devices in upstream manufacturing, and also to check whether the products are compliant with rail standards and client requirements. This paper deals with designing autonomic computing capabilities, specifically self-awareness, to a rail profile measurement system based on laser range finding, and then evaluating their suitability for the following tasks: Automatically detect changes in both the working environment and the operating conditions, and warn process computers and operators of the rail rolling mill when working conditions indicate that the accuracy of the inspection system has fallen below a given threshold.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Geometric Reconstruction and Measurement of Long Steel Products Using 3-D
           Sensors in Real Time
    • Authors: Rubén Usamentiaga;Daniel F. Garcia;Francisco Javier delaCalle Herrero;
      Pages: 5476 - 5486
      Abstract: Calibration, registration, reconstruction, and measurement are the fundamental tasks required for the inspection of dimensions in long steel products. Calibration is performed offline. The rest of the tasks are performed repeatedly while the long steel product is moved under 3-D reconstruction sensors. This study proposes robust methods for the reconstruction of long steel products. In addition, measurement procedures for some representative dimensions are presented. Three different reconstruction procedures are proposed—reconstruction based on geometric primitives in the model of the product, reconstruction based on local fitting, and reconstruction based on piecewise linear approximation. Tests on synthetic on real data indicate excellent performance in terms of computational costs and measurement accuracy. Conclusions also provide recommendations for the application of the proposed reconstruction procedures depending on whether a model is available or not, and the type of features that need to be calculated for the long steel products.1
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Comprehensive Overview and Comparison of ANSI Versus IEC Short-Circuit
           Calculations: Using IEC Short-Circuit Results in IEEE 1584 Arc Flash
           Calculations
    • Authors: Afshin Majd;Robert Luo;Marvin Antony Devadass;Jim Phillips;
      Pages: 5487 - 5493
      Abstract: In this paper, we review both ANSI/IEEE and IEC short-circuit calculation methods. We discuss and compare terminology, definitions, and calculation approaches. The advantages and disadvantages of both standards with numerical examples are presented. Identical systems are analyzed using both methods to make a side-by-side comparison of the results. After both methods are introduced in detail and understood, arc flash calculation examples will be provided using IEC short-circuit calculations. Currently, all arc flash calculation methods (including IEEE 1584) focus on three-phase fault currents without being limited to any specific short-circuit standard. In our approach, the IEC method can be effectively used for arc calculations. This approach can be utilized in regions of the world where IEC standards are used for short-circuit calculations.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Discussion of “Nearest and Non-Nearest Three Vector Modulations of NPCI
           Using Two-Level Space Vector Diagram—A Novel Approach”
    • Authors: Alex Ruderman;
      Pages: 5494 - 5494
      Abstract: Presents a comments on the paper, ”Nearest and non-nearest three vector modulations of NPCI using two-level space vector diagram - a novel approach,” (Babu, N. and Agarwal, P.), IEEE Trans. Ind. Electron., vol. 60, no. 5, pp. 1999-2009, 2013.
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
  • Response to Discussion on “Nearest and Non-Nearest Three Vector
           Modulations of NPCI Using Two-Level Space Vector Diagram—A Novel
           Approach”
    • Authors: Narendra Babu A;Pramod Agarwal;
      Pages: 5495 - 5496
      PubDate: Sept.-Oct. 2019
      Issue No: Vol. 55, No. 5 (2019)
       
 
 
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