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  Subjects -> ELECTRONICS (Total: 179 journals)
Showing 1 - 200 of 277 Journals sorted alphabetically
Acta Electronica Malaysia     Open Access  
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 7)
Advances in Electrical and Electronic Engineering     Open Access   (Followers: 5)
Advances in Electronics     Open Access   (Followers: 78)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Microelectronic Engineering     Open Access   (Followers: 13)
Advances in Power Electronics     Open Access   (Followers: 33)
Advancing Microelectronics     Hybrid Journal  
Aerospace and Electronic Systems, IEEE Transactions on     Hybrid Journal   (Followers: 313)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 24)
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: 13)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 28)
Bioelectronics in Medicine     Hybrid Journal  
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 19)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 36)
Biomedical Instrumentation & Technology     Hybrid Journal   (Followers: 6)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 12)
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: 8)
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: 266)
Edu Elektrika Journal     Open Access   (Followers: 1)
Electrica     Open Access  
Electronic Design     Partially Free   (Followers: 105)
Electronic Markets     Hybrid Journal   (Followers: 7)
Electronic Materials Letters     Hybrid Journal   (Followers: 4)
Electronics     Open Access   (Followers: 86)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 10)
Electronics For You     Partially Free   (Followers: 92)
Electronics Letters     Hybrid Journal   (Followers: 26)
Elkha : Jurnal Teknik Elektro     Open Access  
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 51)
Energy Harvesting and Systems     Hybrid Journal   (Followers: 4)
Energy Storage Materials     Full-text available via subscription   (Followers: 3)
EPJ Quantum Technology     Open Access  
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: 189)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IACR Transactions on Symmetric Cryptology     Open Access  
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 97)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 77)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 46)
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: 66)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 70)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 56)
IEEE Transactions on Circuits and Systems for Video Technology     Hybrid Journal   (Followers: 19)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 40)
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: 71)
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 Microwaves, Antennas & Propagation     Hybrid Journal   (Followers: 35)
IET Nanodielectrics     Open Access  
IET Power Electronics     Hybrid Journal   (Followers: 46)
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: 58)
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 24)
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: 10)
International Journal of Antennas and Propagation     Open Access   (Followers: 11)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 5)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 6)
International Journal of Control     Hybrid Journal   (Followers: 12)
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: 2)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Image, Graphics and Signal Processing     Open Access   (Followers: 14)
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 8)
International Journal of Nano Devices, Sensors and Systems     Open Access   (Followers: 12)
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: 24)
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: 10)
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: 24)
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: 7)
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 8)
Journal of Electronic Design Technology     Full-text available via subscription   (Followers: 6)
Journal of Electronics (China)     Hybrid Journal   (Followers: 4)
Journal of Energy Storage     Full-text available via subscription   (Followers: 4)
Journal of Engineered Fibers and Fabrics     Open Access  
Journal of Field Robotics     Hybrid Journal   (Followers: 2)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 167)
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: 7)
Journal of Low Power Electronics and Applications     Open Access   (Followers: 9)
Journal of Microelectronics and Electronic Packaging     Hybrid Journal  
Journal of Microwave Power and Electromagnetic Energy     Hybrid Journal  
Journal of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 10)
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: 28)
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 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: 5)
Microelectronics and Solid State Electronics     Open Access   (Followers: 18)
Nanotechnology Magazine, IEEE     Full-text available via subscription   (Followers: 33)
Nanotechnology, Science and Applications     Open Access   (Followers: 6)
Nature Electronics     Hybrid Journal  
Networks: an International Journal     Hybrid Journal   (Followers: 5)
Open Electrical & Electronic Engineering Journal     Open Access  
Open Journal of Antennas and Propagation     Open Access   (Followers: 8)
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: 1)
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)
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 53)
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: 75)
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 13)
Solid-State Electronics     Hybrid Journal   (Followers: 9)
Superconductor Science and Technology     Hybrid Journal   (Followers: 2)
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)
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
Industrial Electronics, IEEE Transactions on
Journal Prestige (SJR): 2.192
Citation Impact (citeScore): 9
Number of Followers: 58  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0278-0046
Published by IEEE Homepage  [191 journals]
  • IEEE Transactions on Industrial Electronics publication information
    • 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: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • IEEE Industrial Electronics Society Information
    • 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: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • IEEE Transactions on Industrial Electronics Information for Authors
    • Abstract: These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Model-Based Control for Power Converters With Variable Sampling Time: A
           Case Example Using Five-Phase Induction Motor Drives
    • Authors: Manuel R. Arahal;Cristina Martin;Federico Barrero;Ignacio Gonzalez-Prieto;Mario J. Duran;
      Pages: 5800 - 5809
      Abstract: Discrete-time control of power converters without modulation blocks have been considered in recent times in modern high-performance electromechanical drives, particularly with the appearance of model predictive control in its finite set version. The shortcomings produced by the fixed discretization of time used in this kind of control systems has been analyzed, and several methods have been put forward to deal with them. Most of the alternatives increase the complexity of the controller introducing different analytical modulation methods. However, a variable sampling time can be a simpler and more natural solution, at the expense of using a less-known paradigm for implementation. This paper introduces a new control approach based on a model of the system as in predictive controllers but using variable sampling time. It can be applied to modern power converters and drives, including conventional three-phase or advanced multiphase ones. Experimental results are provided to test the ability of the controller using a five-phase induction motor drive as a case example.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Robust Analytic Design of Power-Synchronization Control
    • Authors: Lennart Harnefors;Marko Hinkkanen;Usama Riaz;F. M. Mahafugur Rahman;Lidong Zhang;
      Pages: 5810 - 5819
      Abstract: This paper addresses robust design of the active-power and dc-link control loops of power-synchronization control. Robustness is obtained by analytic gain selections, which give large enough stability margins. The proposed design allows robust stability irrespective of the grid strength and of the operating point, the latter with one exception. The proposed design is compared to design based on the principle virtual synchronous machine. Experiments show that the time-domain results correlate well with the frequency-domain results.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • An Improved Model Predictive Direct Torque Control Strategy for Reducing
           Harmonic Currents and Torque Ripples of Five-Phase Permanent Magnet
           Synchronous Motors
    • Authors: Guibin Li;Jiefeng Hu;Yongdong Li;Jianguo Zhu;
      Pages: 5820 - 5829
      Abstract: Five-phase permanent magnet synchronous motors offer merits of high fault tolerant capability and high torque per rms ampere and, thus, are suitable for applications, such as aerospace and electric vehicles. However, the complex machine model causes difficulties in controller design. Besides, having 32 voltage vectors with various effects on currents and torque, the selection of the optimal switching state becomes a challenge to achieve a performance tradeoff. This paper proposes an improved model predictive direct torque control (MPDTC) strategy consisting of a quadratic evaluation method (QEM) and a harmonic voltage elimination method (HVEM). In QEM, the preliminary vector is first chosen from the vectors of the outer decagon according to a cost function for torque and flux regulation. This preliminary vector, composed of three sets of different amplitudes, is further synthesized according to the error between the actual torque/flux and the references. In this way, the optimal voltage vector can be obtained without significantly increasing the computational burden. In HVEM, by subtracting the harmonics voltage component from the vector determined previously in QEM, the final voltage vector is obtained for mitigating stator harmonic currents. The proposed control strategy is compared with the conventional MPDTC approach. The results confirm the effectiveness of the proposed methods with good steady-state performance while maintaining quick dynamic responses.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • General Analytical Modeling for Magnet Demagnetization in Surface Mounted
           Permanent Magnet Machines
    • Authors: Baocheng Guo;Yunkai Huang;Fei Peng;Jianning Dong;
      Pages: 5830 - 5838
      Abstract: This paper proposes an analytical model for the prediction of airgap magnetic field distribution for axial flux permanent magnet (AFPM) machine with partial magnet demagnetization. The AFPM machine geometry is first converted to a polar representation. Consequently, the subdomain model based on current sheet technique is developed. Then current sheet representation of PM is derived to consider the partial demagnetization using superposition principle. The back electromagnetic forces and cogging torque are obtained accordingly based on Maxwell's equations. The results show that the results of proposed approach agrees with that of finite-element method. The model is further validated by experiments under both healthy and demagnetized conditions, which can validate the proposed approach. Main contribution of the work is to consider the partial irreversible demagnetization. Moreover, the proposed method is applicable for both AFPM and radial flux permanent magnet machine.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Saliency-Based Sensorless Control for SynRM Drives With Suppression of
           Position Estimation Error
    • Authors: Chengrui Li;Gaolin Wang;Guoqiang Zhang;Dianguo Xu;Dianxun Xiao;
      Pages: 5839 - 5849
      Abstract: Pulsating high-frequency (HF) signal injection is a common saliency-based sensorless control method applied for synchronous reluctance motor (SynRM) drives. However, the accuracy of the rotor position estimation deteriorates due to severe cross-coupling effect and voltage fluctuations. To solve this problem, a measured reference frame HF voltage injection (MHFVI) method is proposed in this paper. A total of two discontinuous pulsating square-wave voltage signals are injected along with two measured axes, and position information is extracted with a cross-coupling factor (CCF) introduced, which can inherently account for the estimation error caused by the cross-coupling effect. The signal processing scheme of the proposed MHFVI method is further developed to be robust to voltage errors, meanwhile has less fluctuation in the position estimation error. The position estimation error is investigated and analyzed based on the finite element analysis results and the introduced CCF is calculated based on the SynRM current–flux characteristics models. Finally, the proposed method is verified by experiments on a 3-kW SynRM drive platform.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Series-Connected Multilevel Converter: Topology, Modeling, and Control
    • Authors: Apparao Dekka;Bin Wu;Mehdi Narimani;
      Pages: 5850 - 5861
      Abstract: Cascaded H-bridge (CHB) is a promising topology for medium-voltage high-power applications. CHB consists of low-power H-bridge modules in each phase, and these modules are connected in a cascade manner to achieve multilevel operation. However, CHB requires a phase-shifting transformer with multiple secondary windings to generate an isolated dc source for each module, and this requirement increases the overall system cost. In this paper, a series connection of low-power modules is employed to realize a new power converter called a series-connected multilevel converter. Each phase of the proposed topology requires a single isolated dc source. Hence, the required number of secondary windings is considerably reduced. This approach also minimizes the complexity and cost of the overall system. The operation of the proposed topology is presented by using three-level neutral point clamped modules in each phase. Model predictive control (MPC) is employed to control the dc-bus capacitor voltage and output currents of the proposed topology. A discrete-time mathematical model of the proposed topology is also developed to predict the future behavior of control variables. The performance of the proposed topology with MPC is verified through MATLAB simulations and a scaled-down laboratory prototype.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Comprehensive Comparison of Rotor Permanent Magnet and Stator Permanent
           Magnet Flux-Switching Machines
    • Authors: Peng Su;Wei Hua;Zhongze Wu;Zhe Chen;Gan Zhang;Ming Cheng;
      Pages: 5862 - 5871
      Abstract: This paper compares two flux-switching machines, namely, one stator permanent magnet flux-switching machine and one rotor permanent magnet flux-switching (RPM-FS) machine, with the same overall dimensions, main material properties, and current density. The comparison of characteristics is conducted from two perspectives, i.e., the electromagnetic torque production mechanism and torque (power)-sizing equation. The contribution of harmonics to average electromagnetic torque is analyzed based on the modulation principle and gearing effect, which reflects the similarities and differences between two FS machines in torque production mechanism. Moreover, torque performances are investigated from the viewpoints of magnetic parameters and electrical parameters. Then, electromagnetic performances including overload capability, flux-weakening capacity, and efficiency are analyzed and compared further. The predicted results indicate the RPM-FS machine exhibits a larger torque capability, a lower torque ripple, and improved flux-weakening capacity. The finite-element analysis predicted results are validated by experiments on two prototype machines.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A New Hybrid Excitation Permanent Magnet Machine With an Independent AC
           Excitation Port
    • Authors: Daohan Wang;Dengxu Zhang;Donghui Xue;Chen Peng;Xiuhe Wang;
      Pages: 5872 - 5882
      Abstract: This paper proposes a novel hybrid excitation permanent magnet (PM) machine with an independent ac excitation port to extend the speed range and improve the torque capability. The proposed machine is characterized by an axial stator placed in one side of the rotor, which provides a shunted flux path of the radial stator. The prominent merit of the proposed machine is that it can make better utilization of the PM flux and offer a large flux regulation capability because the radial flux and the axial flux are in parallel to each other. Thorough analysis of the field distribution is performed by three-dimensional (3-D) finite-element analysis, and different operation modes of the proposed machine are illustrated and compared. Then, the flux regulation capability of the machine is analyzed using the simplified magnetic equivalent circuit, which is proved to give reasonable precision, indicating that the flux regulation ratio only depends on the design parameters of the ac excitation port. Finally, a 36-slot/six-pole prototype using the proposed configuration is built and tested. It is verified that the proposed machine exhibits excellent performance of flux regulation, thus offering a good potential to be used in wide-speed-range driving applications.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Efficiency Estimation of the Induction Machine by Particle Swarm
           Optimization Using Rapid Test Data With Range Constraints
    • Authors: Mahmud Ghasemi Bijan;Pragasen Pillay;
      Pages: 5883 - 5894
      Abstract: Temperature rise of an induction machine increases losses and decrease in the efficiency. The temperature rise depends on the machine design. It takes several hours after starting a machine to reach to thermal stability. In most of the in situ efficiency estimation methods, it is required to obtain the operating data of the machine at a thermally stable condition, which needs a long running time of the machine. In this paper, a method based on a particle swarm optimization (PSO) algorithm is proposed, which can estimate the machine efficiency at different loads with thermal stability. The machine operation data at the first 30 min after the start rather than data at a thermal stability condition are used in the method. The proposed algorithm utilizes two approaches to predict a full-load temperature at a thermally stable condition. The first approach is based on the insulation class of the machine and uses the equivalent circuit. The second approach is based on the trend of the temperature rise in the first 30 min of running the machine after the start. Furthermore, a method is proposed to narrow the parameters range, which helps the PSO to converge to the right answer. All results are validated by the experimental results.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Adaptive Voltage Position Control for Pulse Power Supply in Electrical
           Discharge Machining
    • Authors: Fei Yang;Jiao Yang;Kai Yao;Han Hua;
      Pages: 5895 - 5906
      Abstract: In order to improve the power efficiency and dynamic response of the pulse power supply in electrical discharge machining (EDM), an adaptive voltage position control with a flexible ability of the discharge energy adjustment, dedicating to the pulse power supply in EDM, is proposed in this paper. By introducing the sum of the gap voltage and current as a control object, the voltage mode and the current mode control can be switched freely, which fits the discharge gap characteristics. Based on the analysis of the dynamic response and the steady state of the converter, the design of key power components and control parameters are given. As a result, a fast switch between the voltage control and current control, a high dynamic response on the gap state changing, and a well-discharge current as well as a discharge energy control in a discharge period can be achieved, which means a high power efficiency, a high machining consistency, and a high machining speed for the pulse power supply.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • High Bandwidth Envelope Tracking Power Supply With Pulse Edge Independent
           Distribution Method
    • Authors: Huan Xi;Juan Cao;Ning Liu;Xinbo Ruan;Zhi Fang;Baojian Ji;
      Pages: 5907 - 5917
      Abstract: Switching-linear hybrid envelope tracking (SLH ET) power supplies can achieve both high efficiency and high bandwidth. However, the switching frequency is often required to be far higher than or at least equal to the envelope bandwidth. With the modulation methods advance, the increasing envelope bandwidth may lead to a too high switching frequency to implement. This paper proposes an SLH ET power supply, consisting of a multilevel converter and a linear amplifier connected in series. Based on the multicell configuration of the multilevel converter, a pulse edge independent distribution method is proposed, which can break the control pulses for the multilevel converter into independent rising and falling edges, and rebuild them with new sequences. It can not only reduce the switching frequency to 1/n (n ∊ N) of the envelope bandwidth but also extend the pulsewidths to provide a more reliable and effective driving for high bandwidth applications. A prototype for 2 MHz sine-wave tracking, with 7–27-V output voltage and 90-W peak output power, is fabricated and tested. It is also verified by a 5- and a 10-MHz bandwidth communication envelope. The experimental results validate the proposed method.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Modular On-Road AGV Wireless Charging Systems Via Interoperable Power
           Adjustment
    • Authors: Shyh-Jier Huang;Tsong-Shing Lee;Wei-Hua Li;Ruei-Yuan Chen;
      Pages: 5918 - 5928
      Abstract: This paper proposes a modular on-road wireless power transfer system with interoperable power adjustment mechanism. The paper is anticipated to enhance the capability of on-road charging during the movement of automated guided vehicles (AGV), by which the traveling mileage is increased, while the battery volume is decreased. The system design includes an interoperable power adjustment technique based on the detected impedance, and the moving position of AGV can be, hence, comprehended so as to facilitate the adjustment of the output power from each transmission module in a more flexible way. Through the investigation of on-road charging efficiency, all of coil magnetic analysis, misalignment charging evaluation, system stress simulation, and resonant characteristics investigation are performed. Experimental results gained from software simulation and hardware realization are beneficial for AGV charging applications.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Analysis of the Acoustic Noise Spectrum of Domestic Induction Heating
           Systems Controlled by Phase-Accumulator Modulators
    • Authors: Jorge Villa;José I. Artigas;José R. Beltrán;Alberto Domínguez Vicente;Luis A. Barragán;
      Pages: 5929 - 5938
      Abstract: In domestic induction heating applications, the modulation technique applied to the inverter has a high influence on the acoustic noise emissions. These noise emissions must be avoided, since they may be audible and annoying to the final user. This paper analyzes the acoustic noise emissions that appear when a series half-bridge resonant inverter is operated with a phase-accumulator-based modulator. This modulation technique has the advantage of operating in the frequency domain, and it is compared with the classical pulsewidth modulator regarding the audible noise generated. The frequencies of the tones in the acoustic noise spectrum are theoretically calculated from the parameters of the phase-accumulator-based modulator. The spectral flatness measure is used to quantify the number of cases in which tones are generated by the modulation. Two techniques are applied to the phase-accumulator-based modulator, and their effect is tested. Theoretical results are experimentally verified.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Fully Soft-Switched Bidirectional DC–DC Converter With Only One
           Auxiliary Switch
    • Authors: Saba Rahimi;Mahdi Rezvanyvardom;Amin Mirzaei;
      Pages: 5939 - 5947
      Abstract: In this paper, a fully soft-switched bidirectional dc–dc converter is proposed. All semiconductor devices are soft switched, while its control circuit remains pulsewidth modulated. This condition is achieved only by one auxiliary switch. So, the proposed topology has less complexity in comparison with other similar structures. The energy conversion through the proposed topology during buck and boost modes is highly efficient due to achieved soft-switching condition. The auxiliary circuit operates once during each switching cycle. The converter is analyzed and a 250-W laboratory prototype of the proposed converter is constructed. The experimental results are presented that confirm the theoretical analysis.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Bidirectional Two-Switch Flyback Converter With Cross-Coupled LCD
           Snubbers for Minimizing Circulating Current
    • Authors: Nurhakimah Mohd Mukhtar;Dylan Dah-Chuan Lu;
      Pages: 5948 - 5957
      Abstract: This paper proposes a novel isolated bidirectional two-switch flyback converter with two integrated non-dissipative inductor–capacitor–diode (LCD) snubbers. In the proposed topology, the main flyback transformer and the LCD snubbers are cross coupled to minimize circulating current that would occur in the non-cross-coupled case, in addition to recycle leakage energy and protect the power transistors. The same current circulation issue also occurs in the bidirectional flyback converter with conventional resistor–capacitor–diode (RCD) snubbers. The main objective of this paper is to illustrate this issue and propose an alternate circuitry to reduce the current circulation and improve the conversion efficiency. The experimental results of a laboratory prototype are reported to verify the design.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Control Strategy for Efficiency Optimization and Wide ZVS Operation
           Range in Bidirectional Inductive Power Transfer System
    • Authors: Xiaoming Zhang;Tao Cai;Shanxu Duan;Hao Feng;Hongsheng Hu;Jintao Niu;Changsong Chen;
      Pages: 5958 - 5969
      Abstract: The efficiency of bidirectional inductive power transfer (BIPT) systems is strongly dependent on the load. Besides, the soft-switching operation of power switches is critical to high-frequency converter in the BIPT systems. In this paper, a triple-phase-shift (TPS) control strategy is proposed to achieve load matching while realizing zero voltage switching (ZVS) for all power switches within the entire power range. The load matching condition of the BIPT system with double-sided LCC compensation network is analyzed. And a dual side phase shift control is proposed to adjust power flow while realizing load matching. To realize ZVS operation, the third phase shift between primary and secondary side is introduced as an extra control variable. A time domain model of double-sided LCC compensation network is established to analyze the ZVS range. With the proposed TPS control, wide ZVS operation range of the system can be achieved while maintaining load matching. At last, a scale down prototype of 1 kW BIPT system is developed. The experimental results show good agreement with theoretical analysis, all switches realize ZVS within the entire power range and a peak efficiency of 94.83% is achieved.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Modified Series and Tapped Switched-Coupled-Inductors Quasi-Z-Source
           Networks
    • Authors: Saeed Sharifi;Mohammad Monfared;
      Pages: 5970 - 5978
      Abstract: This paper proposes two coupled-inductors-based Z-source networks, called the modified series and tapped switched-coupled-inductors quasi-Z-source networks (mSSCL-qZSN and mTSCL-qZSN, respectively). These networks offer high voltage gains with less-than-unity winding turn ratios $(n < {text{1)}}$, resulting in a reduced inductive element size. Other advantages include a less number of active components and their lower ratings and a higher efficiency. In addition, a lower magnetic core size is required for the proposed ZSNs due to the lower peak magnetizing current. The performance principles and detailed comparative analysis are provided and confirmed through experiments on a 200-W dc–dc converter.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Novel Battery Management System Architecture Based on an Isolated
           Power/Data Multiplexing Transmission Bus
    • Authors: Ruoqi Zhang;Jiande Wu;Ruichi Wang;Rui Yan;Yue Zhu;Xiangning He;
      Pages: 5979 - 5991
      Abstract: Hardware structure is a basic characteristic of a battery management system (BMS), which influences the overall performance of battery packs. This paper presents a novel BMS architecture based on the power/data time division multiplexing transmission technique. In the proposed system, a common bus is employed to transfer power and data simultaneously, so the system wiring is simplified. The system consists of a pack management unit and several cell management units (CMUs). The circuit of the CMU is compact and achieves conventional management functions like status monitoring and active cell balancing; thus, it can be integrated with battery cell to be an intelligent cell. The timing sequence of the system is presented, and the design considerations are discussed in detail, including terminal resistance selection, maximum node number calculation, and power consumption analysis. Finally, a simulation based on MATLAB is carried out and an experimental prototype system with six nodes is built, which verifies the correctness of the architecture and proves the feasibility in practical applications.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Generalized Switching Modification Method Using Carrier Shift for DC-link
           Capacitor RMS Current Reduction in Real-Time Implementation
    • Authors: Ki-Young Choi;Sang-Il Kim;Sang-Min Jung;Rae-Young Kim;
      Pages: 5992 - 6001
      Abstract: In this paper, a generalized switching modification method is proposed to reduce the root-mean-square (rms) current flowing into a dc-link capacitor in a dc–dc–ac structure consisting of a boost converter and a three-phase inverter. To analyze the current flowing into the capacitor, we analyze the currents at the respective converter and inverter sides. Based on this analysis, we derive an analytical method to find the modification time between the converter and inverter pulsewidth modulation (PWM) carriers through a Fourier series and approximation to facilitate real-time implementation. Real-time implementation of the modification time calculated by the derived method is described. To verify the validity of the proposed method, experimental results are presented based on a 1-kVA dc–dc–ac prototype. The proposed method has a better capacitor rms current reduction performance than the conventional method in various inverter power factors and PWM strategies. Especially, it has an excellent performance in mid-power factor level (0.95–0.1).
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Virtual Inductance for Stable Operation of Grid-Interactive Voltage Source
           Inverters
    • Authors: Aswad Adib;Behrooz Mirafzal;
      Pages: 6002 - 6011
      Abstract: In this paper, a feedforward virtual inductance control strategy is developed for the stability of voltage source inverters (VSIs) in weak grids. A weak grid is characterized by a low short-circuit ratio and a low inertia constant, in which VSIs become susceptible to voltage distortions and instability. The proposed feedforward virtual inductance term is integrated into the current control loops of grid-tied VSIs. In this paper, the effectiveness of the virtual inductance control strategy in weak grids is first proved through closed-loop transfer function analysis and then the system's root locus analysis to determine the stability region of the system versus the grid impedance. The developed virtual inductance controller is also verified through laboratory experiments for different weak grid scenarios.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Data-Driven Condition Monitoring Approaches to Improving Power Output of
           Wind Turbines
    • Authors: Peng Qian;Xiandong Ma;Dahai Zhang;Junheng Wang;
      Pages: 6012 - 6020
      Abstract: This paper presents data-driven approaches to improve the active power output of wind turbines based on estimating their health condition. The main procedure includes estimations of fault degree and health condition level, and optimal power dispatch control. The proposed method can adjust the active power output of individual turbines according to their health condition and can thus optimize the total energy output of a wind farm. In the paper, extreme learning machine algorithm and Bonferroni interval are applied to estimate fault degree, while an analytic hierarchy process is used to estimate the health condition level. A scheme for power dispatch control is formulated based on the estimated health condition. Models have been identified from supervisory control and data acquisition data acquired from an operational wind farm, which contains temperature data of gearbox bearing and generator winding. The results show that the proposed method can maximize the operation efficiency of the wind farm while significantly reducing the fatigue loading on the faulty wind turbines.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • $mathcal+{H}_{infty+}$ +State+Feedback+Controllers+Based+on+Linear+Matrix+Inequalities+Applied+to+Grid-Connected+Converters&rft.title=Industrial+Electronics,+IEEE+Transactions+on&rft.issn=0278-0046&rft.date=2019&rft.volume=66&rft.spage=6021&rft.epage=6031&rft.aulast=Montagner;&rft.aufirst=Gustavo&rft.au=Gustavo+Guilherme+Koch;Luiz+Antonio+Maccari;Ricardo+C.+L.+F.+Oliveira;Vinícius+Foletto+Montagner;">Robust $mathcal {H}_{infty }$ State Feedback Controllers Based on Linear
           Matrix Inequalities Applied to Grid-Connected Converters
    • Authors: Gustavo Guilherme Koch;Luiz Antonio Maccari;Ricardo C. L. F. Oliveira;Vinícius Foletto Montagner;
      Pages: 6021 - 6031
      Abstract: This paper provides robust $mathcal {H}_{infty }$ state feedback controllers suitable for implementation in three-phase grid-connected converters. This control strategy is known to provide optimal rejection of disturbances, but usually leads to high control gains, that may be difficult to be implemented in practice. To mitigate this problem, a linear matrix inequality condition based on slack variables is proposed, which allows to impose bounds on the control gains in a less conservative way than conventional quadratic stability. The performance is proven to be superior to similar $mathcal {H}_{infty }$ state feedback controllers in the literature, providing an upper bound for the converter output admittance and experimental grid currents complying with the IEEE Standard 1547.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Improved Energy Management Algorithm With Time-Share-Based Ultracapacitor
           Charging/Discharging for Hybrid Energy Storage System
    • Authors: Mahendra Chandra Joshi;Susovon Samanta;
      Pages: 6032 - 6043
      Abstract: The efficiency, durability, and health of the energy storage system components depend on controlling the power flow subjected to proper operational constraints. It is achieved by energy management algorithm (EMA). Conventional EMAs restrict the ultracapacitor (UC) operation to a reference voltage to prevent it from overcharging/undercharging. This leads to very narrow utilization of the UC voltage range. However, UC voltage can safely be varied from zero to maximum-rated voltage. Rather than employing a UC voltage control loop that operates concurrently to transient load demand, a time-share-based approach has been used for UC charging/discharging. Hence, EMA has been modified in the present work by utilizing the UC voltage band instead of a UC reference voltage, which increases its power delivery capacity by approximately two to four times. In this paper, the proposed EMA improves the transient performance of the system and reduces the UC size. An experimental prototype of the system is designed, and the proposed EMA is tested in the different operating regions for validation.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Parameter Estimation of a Grid-Connected VSC Using the Extended Harmonic
           Domain
    • Authors: Miguel Esparza;Juan Segundo;Carlos Gurrola-Corral;Nancy Visairo-Cruz;Ernesto Bárcenas;Emilio Barocio;
      Pages: 6044 - 6054
      Abstract: This paper proposes a light, flexible, and yet reliable multiparametric estimation algorithm for grid-connected voltage-source-converter-based systems. This approach combines the nonlinear least squares (NLSQ) fitting algorithm and the steady-state extended harmonic domain (EHD) model to take into account the harmonic effects. The EHD model is used to take advantage of the harmonic content of the electrical signals to provide robustness and improved performance to the NLSQ estimation methodology. In addition, this harmonic formulation reduces the necessity of synchronized measurements. Details of the implementation are provided by an experimental case study, in which the grid equivalent (Thevenin voltage, inductance, and resistance), the ac-side filter (inductance and resistance), and the converter switching and conduction loss resistance are accurately estimated for three different operating conditions.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Development of a Novel HVdc Circuit Breaker Combining Liquid Metal Load
           Commutation Switch and Two-Stage Commutation Circuit
    • Authors: Yifei Wu;Yi Wu;Mingzhe Rong;Fei Yang;
      Pages: 6055 - 6064
      Abstract: The emerging demand on development of high-voltage direct current (HVdc) networks brings about an increasingly urgent need for a fast and reliable HVdc circuit breaker. This paper proposes a novel topology of HVdc circuit breaker combining a liquid metal load commutation switch and a two-stage commutation circuit, which offers an effective solution for isolating faults while preserving larger current breaking capability and lower overvoltage rate of rise. With the topology optimized in terms of circuit parameters for determining their optimum design values, the handling of short-circuit faults for the proposed circuit breaker in HVdc application is predicted theoretically. Finally, preliminary tests from a developed low-power prototype are presented together with a comparative simulation study provided to verify the performance of the proposed HVdc circuit breaker.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Optimal Energy Management and Control in Multimode Equivalent Energy
           Consumption of Fuel Cell/Supercapacitor of Hybrid Electric Tram
    • Authors: Yu Yan;Qi Li;Weirong Chen;Bo Su;Jiawei Liu;Lei Ma;
      Pages: 6065 - 6076
      Abstract: For low energy consumption and operational stability, multimode equivalent energy consumption, an optimal energy management and control method, is proposed in this paper. This method effectively solves the problem of energy distribution between the primary power—a high-power fuel cell and an auxiliary power—and a supercapacitor, in complex operating conditions. In all four states of the hybrid electric tram, i.e., traction, coasting, braking, and station parking, the optimal energy distribution method, with the highest energy efficiency of the tram, is obtained through the whole system modeling and the equivalent energy consumption calculation. In order to verify the responding speed, this method gets the analytical solution and is tested on the RT-LAB hardware-in-the-loop simulation platform. The results show that compared to the power following method the new method can reduce the overall tram energy consumption by 2.5% in complex operating conditions. What is more, when this method is successfully applied to the world's first commercial fuel cell/supercapacitor LF-LRV hybrid tram, its energy consumption and fuel cell system (FCS) output fluctuation rate are effectively reduced according to the operational data, which indicates a good chance of extending the life of the FCS as well.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Short-Term Prognostics of PEM Fuel Cells: A Comparative and Improvement
           Study
    • Authors: Hao Liu;Jian Chen;Daniel Hissel;Hongye Su;
      Pages: 6077 - 6086
      Abstract: As one of the most promising types of fuel cells, the proton exchange membrane fuel cells (PEMFCs) can be utilized in many applications. However, it still faces two main challenges before large-scale industrial applications, namely short lifetime and high costs. The aim of this paper is to establish an accurate online short-term prognostics method to help users extend the lifetime and reduce the cost of PEMFCs. First, we compare the short-term prognostics accuracy and computational efficiency of several different methods including the Elman neural network, the group method of data handling, the adaptive neuro-fuzzy inference system (ANFIS) with different fuzzy inference system creation strategies, and the wavelet decomposition approach. Test results show that the ANFIS with fuzzy c-means (ANFIS-FCM) strategy has the best short-term prognostics performance. Then, we propose an automatic parameter adjustment method for ANFIS-FCM by using the particle swarm optimization (PSO) algorithm. Test results show that the PSO algorithm can effectively adjust the parameters and achieve improved prognostics results. Finally, the proposed prognostics methods are verified on a PEMFC experimental platform. Experimental results show that the proposed methods have great potential for practical applications.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Peer-to-Peer Energy Trading in a Prosumer-Based Community Microgrid: A
           Game-Theoretic Model
    • Authors: Amrit Paudel;Kalpesh Chaudhari;Chao Long;Hoay Beng Gooi;
      Pages: 6087 - 6097
      Abstract: This paper proposes a novel game-theoretic model for peer-to-peer (P2P) energy trading among the prosumers in a community. The buyers can adjust the energy consumption behavior based on the price and quantity of the energy offered by the sellers. There exist two separate competitions during the trading process: 1) price competition among the sellers; and 2) seller selection competition among the buyers. The price competition among the sellers is modeled as a noncooperative game. The evolutionary game theory is used to model the dynamics of the buyers for selecting sellers. Moreover, an M-leader and N-follower Stackelberg game approach is used to model the interaction between buyers and sellers. Two iterative algorithms are proposed for the implementation of the games such that an equilibrium state exists in each of the games. The proposed method is applied to a small community microgrid with photo-voltaic and energy storage systems. Simulation results show the convergence of the algorithms and the effectiveness of the proposed model to handle P2P energy trading. The results also show that P2P energy trading provides significant financial and technical benefits to the community, and it is emerging as an alternative to cost-intensive energy storage systems.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Spline-Based Trajectory Generation for CNC Machines
    • Authors: Tim Mercy;Nicolas Jacquod;Raoul Herzog;Goele Pipeleers;
      Pages: 6098 - 6107
      Abstract: Manufacturing of workpieces with computerized numerical control machines requires computing machine tool trajectories that fast and accurately track the desired workpiece contour. This paper presents a novel B-spline trajectory generation method for machine tools. The method solves an optimal control problem to minimize the motion time of the tool, while taking into account the velocity, acceleration, and jerk limits of the tool axes. Furthermore, it directly includes the allowed workpiece tolerance, by constraining the trajectory to lie inside a tube around the nominal geometry contour. This allows exploring the tradeoff between accuracy and productivity, while computing near-optimal trajectories. The presented method creates fluent connections between segments that build up the contour by simultaneously optimizing trajectories for multiple segments. On the other hand, limiting the amount of simultaneously optimized segments and using an efficient problem formulation keeps the computation time acceptable. The trajectory generation method is validated in simulation by comparison with industrial benchmarks, showing a reduction in machining time of more than ${text{10}}%$. The comparison to a state-of-the-art corner smoothing approach shows that the presented method obtains similar or slightly faster trajectories, at a computation time that is up to 45 times lower. In addition, the method is validated experimentally on a three-axis micromilling machine. To easily generate trajectories for different workpieces and machines, the method is included in a user-friendly open-source software toolbox.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Design and Implementation of a Soft Robotic Arm Driven by SMA Coils
    • Authors: Hao Yang;Min Xu;Weihua Li;Shiwu Zhang;
      Pages: 6108 - 6116
      Abstract: Soft robots may potentially be used for human services and complex environmental locomotion. The bodies of the soft robots are made from soft materials to make them safe for human interactions and to enable them to deform enough to adapt to soft or rough terrains. However, their practical applications are limited because their body stiffness is too low and the deformation is continuous, which make it difficult to control their movements. In this paper, the design and implementation of a soft robotic arm driven by shape memory alloy (SMA) coils are reported. The arm is made from soft silicone, and there are three linear Hall sensors in certain slots on the body wall to measure the changes in height as the arm bends. With a compression compensation algorithm, a proportional-integral differential controller is used to precisely control the bending movement. This soft robotic arm can follow a two-dimensional motion with a relatively high accuracy; indeed, it displays quite a remarkable performance considering its low cost, simple structure, easy control, and small bending error. Since this soft arm can be used as the basic driving unit of a soft robot capable of manipulating and locomoting, it has shed light on the applications of SMA soft robots.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Diversity-Based Cooperative Multivehicle Path Planning for Risk Management
           in Costmap Environments
    • Authors: Johnathan Votion;Yongcan Cao;
      Pages: 6117 - 6127
      Abstract: This paper focuses on developing new navigation algorithms for cooperative unmanned vehicles in costmap environments. The vehicles need to plan optimal paths subject to mutual diversity. We first propose three algorithms that can find optimal paths in costmap environments with improved computational efficiency. The proposed algorithms include 1) the scaled A*; 2) the A* plus-plus; and 3) the A* plus-plus with reconstruction. The heuristics of the three algorithms are proved admissible. Then, a diversity-based path planning algorithm is proposed based on the new A star variant algorithms for multiple vehicles to plan diverse paths for risk management. In particular, we propose an iterative segment planner, which generates a set of spatially diverse paths by iteratively planning segments of all paths in a sequential manner. To prevent the generation of spatially close paths, the iterative segment planner utilizes a penalty function to increase the cost of paths that lie near the route(s) assigned to other vehicles. By varying the penalty gains, different degrees of path diversity can be achieved. Some illustrative examples are provided to compare the performance of the proposed algorithms with the standard A* and Dijkstra's algorithms, and show the effectiveness of the proposed diversity-based path planning algorithm.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Analysis of Spoke-Type Brushless Dual-Electrical-Port Dual-Mechanical-Port
           Machine With Decoupled Windings
    • Authors: Xiang Ren;Dawei Li;Ronghai Qu;Wubin Kong;Xun Han;Tonghao Pei;
      Pages: 6128 - 6140
      Abstract: Brushless dual-electrical-port dual-mecha-nical-port (BLDD) machine has become a good candidate to replace the traditional mechanical continuously variable transmission owing to its high compactness, reliability, and torque transmission capability. However, the mutual coupling between two sets of windings fed by different frequency currents leads to strong interference during both health and fault conditions, whereas the coupling effect is difficult to be reduced in the regular BLDD machine due to its operation principle. This paper presents a systematic analysis on a novel spoke-type BLDD (STBLDD) machine, aiming to eliminate coupling of windings. Using the winding function theory, the decoupling principle is analyzed in detail, and corresponding slot/pole combinations are derived. Through finite-element analysis, parameter influences on the performance of this STBLDD machine are then studied. A prototype and test bed have been designed and manufactured, and the experimental results verify the analysis results.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Development of a Planar Piezoelectric Actuator Using
           Bending–Bending Hybrid Transducers
    • Authors: Jie Deng;Yingxiang Liu;Junkao Liu;Dongmei Xu;Yun Wang;
      Pages: 6141 - 6149
      Abstract: A planar piezoelectric actuator with large travel range is presented in this paper. The actuator is composed of four uniform piezoelectric transducers, and each transducer can bend along the horizontal direction or vertical direction independently. Trapezoidal-wave signals are used to excite the hybrid bending of the transducers and form rectangular movements on their driving feet. The actuator can move step by step by the static friction forces in nonresonant mode, and a long reliability life is obtained as there is no wear and tear problem. The operating principle is simulated by finite-element method, which reveals the generation of rectangular trajectory on each driving foot and the large structure stiffness of the actuator. A prototype is fabricated and its experiment system is established. A resolution of 16 nm is achieved at the quasi-static mode, a minimum step distance repeatability error rate of 1.06% is obtained at the stepper mode; the maximum output speed and carrying load of 300 μm/s and 35 kg are achieved at voltage of 400 V$_{{text{p-p}}}$ and frequency of 40 Hz. The experiments also shows that the output speed is linearly related to the exciting voltage; the motion along any direction in the platform is achieved by controlling the voltage signals.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Effect of Third Harmonic Flux Density on Cogging Torque in Surface-Mounted
           Permanent Magnet Machines
    • Authors: H. Y. Sun;K. Wang;
      Pages: 6150 - 6158
      Abstract: Cogging torque, inherent in permanent magnet machines, is closely related to the airgap flux density harmonic contents. The third harmonic can be utilized in combination with the fundamental one to increase the average torque, whilst its relationship with cogging torque is uncertain. The aim of this paper is to investigate the effect of third harmonic in airgap flux density on cogging torque in surface-mounted permanent magnet (SPM) machines considering different slot/pole (S/P) combinations. First, based on the simplified expressions of cogging torque in machines with sinusoidal plus third harmonic (Sine+3rd) airgap flux density, S/P combinations are classified into four cases for discussion. It is found that when Ns /GCD (Ns, Np) ≥ 4 (Ns: slot number; Np: pole number; GCD: great common divisor), third harmonic in airgap flux density has no effect on cogging torque. Otherwise, cogging torque will be generated. Furthermore, two approaches for obtaining the Sine and Sine+3rd airgap flux density, i.e., Sine/Sine+3rd hm and Sine/Sine+3rd Br, are validated, based on which finite-element analyses are carried out on four machines, i.e., 12-slot/10-pole (12S12P), 12S6P, 12S8P, and 12S10P to verify the conclusion. Finally, the 12S8P and 12S10P Sine+3rd SPM machines are prototyped and tested for validation.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Mitigation of Resonance Vibration Effects in Marine Propulsion
    • Authors: Jishnu Kavil Kambrath;Changwoo Yoon;Jose Mathew;Xiong Liu;Youyi Wang;Chandana Jayampathi Gajanayake;Amit Kumar Gupta;Yong-Jin Yoon;
      Pages: 6159 - 6169
      Abstract: Electric propulsion has become the solution for large marine vessels over conventional combustion engine propulsion. An azimuth thruster is the primary propulsion unit in such electrified ships, and it has become prevalent recently. However, the mechanical failures among bevel gear, coupling, and bearing in the thruster are reported commonly, and it may be attributed to the dynamic mismatch and torsional oscillations between the motor drive and mechanical drivetrain systems. One main advantage of using electric propulsion is its flexible and instant torque control that can reduce the torsional stress in the drivetrain. In this paper, a new speed difference-based active torque compensating method is proposed. A detailed model for the azimuth propulsion system is developed, and a power electronics-based controller is used to manage the excessive drivetrain torque caused by a sudden load change. The proposed controller can change the damping ratio by introducing virtual material damping in the system, which decreases the resonant torque amplitude in the driveline. The resonant torque attenuating effects are validated both by simulation and experiment with a multi-inertia model operating at rapid ventilation.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Inverse Compensator for A Simplified Discrete Preisach Model Using
           Model-Order Reduction Approach
    • Authors: Zhi Li;Jinjun Shan;Ulrich Gabbert;
      Pages: 6170 - 6178
      Abstract: The classical Preisach model, which is built by the superposition of a great number of relay operators, is one of the most popular models to represent the hysteretic behaviors in various applications, such as the smart materials-based actuators. However, the construction of the inverse compensator for the classical Preisach model is very challenging for some reasons, first, the analytical inverse of the classical Preisach model is not available, and, second, due to a huge amount of the relay operators the implementation of the inverse compensator is troublesome and causes heavy computational burden. To overcome these drawbacks, a simplified discrete Preisach model is developed in this paper. The simplified model has an explicit expression with respect to the input of the model, thus it is simple to construct its inverse compensator using the inverse multiplicative structure approach. To reduce the computational effort in implementing the inverse compensator, the model-order reduction method is employed to reduce the complexity of the inverse compensator. Experimental tests are carried out to validate the effectiveness of the proposed approach.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Low-Frequency Structure-Control-Type Inertial Actuator Using
           Miniaturized Bimorph Piezoelectric Vibrators
    • Authors: Yili Hu;Renming Wang;Jianming Wen;Jing-Quan Liu;
      Pages: 6179 - 6188
      Abstract: A low-frequency structure-control-type inertial actuator using miniaturized bimorph piezoelectric vibrators is proposed in this paper to achieve high resolution and high stability with a large linear stroke. These vibrators are fabricated by bonding, thinning, and patterning fabrication processes, which are beneficial to realize miniaturization and increase output performance for the system. A theoretical model based on work-energy analysis is established to predict the output displacement characteristics. An experimental system is built to evaluate the performance of the proposed actuator. Experimental results indicate that the stable minimum step displacement is 0.03 μm under a square wave signal of 5 V, 50 Hz, and a clamping difference of 3.5 mm. Under the condition of 7 V and 50 Hz, the sample standard deviation is 0.0337 μm in repeatability test. The proposed actuator achieves a stable and accurate linear bidirectional motion with high resolution, high stability, low power consumption, and a large working stroke.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Dynamic Multilayer Winding Thermal Model for Electrical Machines With
           Concentrated Windings
    • Authors: Xinggang Fan;Dawei Li;Ronghai Qu;Cong Wang;
      Pages: 6189 - 6199
      Abstract: This paper presents a dynamic multilayer winding lumped-parameter thermal model dedicated to electrical machines with concentrated windings. The winding is layered into a series of circular rings by a novel layer strategy according to the winding temperature distribution obtained by a two-dimensional analytical slot winding thermal model. Accordingly, the layer number can be automatically and dynamically adjusted so as to accurately model the winding temperature distribution using the smallest layer number. Besides, the end-winding is also layered similarly to the slot-winding based on the thermal behavior of the nonoverlapping concentrated windings. The proposed winding model could accurately calculate the temperature distribution within the slot, including the winding maximum and average temperature. Experiments on a winding motorette and a water-cooled permanent magnet machines with concentrated winding intended for electric vehicles have been implemented to validate the proposed winding thermal model.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Calculation of Eddy Current Loss in a Tubular Oscillatory LPMSM Using
           Computationally Efficient FEA
    • Authors: Tao Wu;Kang Lu;Jianguo Zhu;Gang Lei;Youguang Guo;Shengwen Tang;
      Pages: 6200 - 6209
      Abstract: In some special oscillatory applications, especially those operated at high speeds, the eddy current loss of a linear permanent-magnet (PM) synchronous machine (LPMSM) should be fully considered because the loss might be large and concentrated in PMs during the oscillation period. This paper presents a loss analysis method based on computationally efficient finite-element analysis (CE-FEA) for a 20-Hz oscillatory tubular LPMSM. Since the mover speed varies with time, an equally divided model in 1/4 period is introduced to calculate the average PM eddy current loss. The flux density curves in PMs are calculated at 18 intervals by the CE-FEA, through which the change rate of the magnetic flux density is analyzed, considering both the entering and leaving effects and coil end effects. The calculation results show that the eddy current loss is obviously concentrated in PMs near the two ends of coils. The calculation results at a speed of 3.6 m/s obtained by the CE-FEA and two-dimensional and three-dimensional time-stepping FEAs are compared to validate the accuracy. Finally, the proposed method is validated by the experimental test results on a prototype LPMSM.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Equivalent Thermal Conductivity Estimation for Compact Electromagnetic
           Windings
    • Authors: Xi Zhang;Tenghui Dong;Fei Zhou;
      Pages: 6210 - 6219
      Abstract: This paper presents a new estimation method for the equivalent thermal conductivities of the compact slot windings formed from round conductors. The estimation accuracy of thermal conductivities is essential for peak temperature prediction to avoid overheating failures in the high power density electromagnetic devices. The compact windings with orderly wound conductors perform better on heat dissipation and take smaller slot space than the random wound types. In recent years, the winding technology has made great improvement, and the compactness of conductors is significantly elevated. After observing the cross section of the windings, the randomness of the wire's layout is greatly reduced and a certain regularity is shown. The proposed estimation method takes the geometric characteristics of the internal structure into account to improve the estimation accuracy of the traditional methods, which use the proportion of each material only. Considering the layout of conductors is not completely regular, the impact of the dislocation between conductors is explored. Then, the conclusion is used to modify the analytical result. The experimental test result shows that the proposed theoretical method is easy to apply and meanwhile performs satisfactory in terms of high accuracy and low computation.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Optimal Design of a Fractional-Order Proportional-Integer-Differential
           Controller for a Pneumatic Position Servo System
    • Authors: Hai-Peng Ren;Jun-Tao Fan;Okyay Kaynak;
      Pages: 6220 - 6229
      Abstract: In this paper, a fractional-order model of pneumatic servo system is introduced by replacing the integer-order dynamic equation with the corresponding fractional order one. Then, a fractional-order proportional-integer-differential (FPID) controller is optimized for the servo system using an online multivariable multiobjective genetic algorithm (MMGA). The proposed MMGA searches in five-dimensional parameter space based on Pareto rank to balance multiobjectives. In order to provide a basis for comparison, the parameters of a integer order proportional-integer-differential (IPID) controller are also optimized using the same method. The performance indices defined for comparison are the steady-state tracking accuracy and the control energy consumption. Additionally, seven other methods from the literature are compared. The experimental results obtained show that the optimized FPID controller results in a better performance than the optimized IPID controller and the other existing approaches.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Multipoint Iterative Learning Model Predictive Control
    • Authors: Jingyi Lu;Zhixing Cao;Furong Gao;
      Pages: 6230 - 6240
      Abstract: Iterative learning model predictive control (ILMPC), endowed with the merits of iterative learning control and model predictive control, has excellent abilities of disturbance rejection and constraints handling. It has been widely applied in regulation of industrial batch processes for its remarkable reference tracking performance. In practice, the presence of strong system nonlinearity fundamentally challenges the model mismatch cyclewise invariance assumption that underlies numerous synthesis of many ILMPC methods. It may further induce additional conservatism and thus ultimately leads to performance degradation. To circumvent this issue, in this paper a novel ILMPC scheme relying upon past error compensation from multiple time instances is presented, in which the associated weights are adaptively optimized, thereby resulting in considerable enhancement of robustness. These superior performances are confirmed by numerical experiments on injection molding process, a typical batch process.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • An Adaptive PI Controller Design for DC-Link Voltage Control of
           Single-Phase Grid-Connected Converters
    • Authors: Meriem Merai;Mohamed Wissem Naouar;Ilhem Slama-Belkhodja;Eric Monmasson;
      Pages: 6241 - 6249
      Abstract: Conventionally, standard proportional and integral (PI) controllers with constant PI gains are commonly used for the dc-link voltage control of single-phase grid-connected converters (GCCs). For such controllers, the selection of the PI gains will lead to a tradeoff between two control objectives: 1) the reduction of the dc-link voltage fluctuations caused by random swings of the active power drawn by the single-phase GCC; and 2) the reduction of the grid current harmonics mainly caused by the 2f oscillation of the active power in single-phase applications. To solve this tradeoff, this paper presents a systematic approach for the design of an adaptive PI controller for the dc-link voltage control of single-phase GCCs. The proposed design approach is simple and it provides a convenient method to properly determine the adaptive PI controller parameters. Representative simulation and experimental results are presented and discussed in order to show the effectiveness of the proposed dc-link voltage controller.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • An Explicit Estimate for the Upper Bound of the Settling Time in
           Fixed-Time Leader-Following Consensus of High-Order Multivariable
           Multiagent Systems
    • Authors: Zongyu Zuo;Qing-Long Han;Boda Ning;
      Pages: 6250 - 6259
      Abstract: In this paper, the fixed-time leader-following consensus problem is investigated for high-order multivariable multiagent systems with external disturbances. A new distributed observer is proposed for each follower under a directed information flow to estimate the leader state in a fixed time. Based on the observer, a novel tracking controller is designed such that the estimated leader state is tracked with disturbance rejection in a fixed time. Consensus conditions are established to guarantee the fixed-time stability. Different from some existing finite-/fixed-time consensus approaches, an explicit estimate for the upper bound of the settling time is derived, which provides additional system specification in advance. Moreover, for disturbance rejection, the chattering phenomenon is effectively reduced by using a distributed multivariable signum function. Finally, illustrative examples are provided to demonstrate the theoretical results.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Collaborative Three-Dimensional Completion of Color and Depth in a
           Specified Area With Superpixels
    • Authors: Lei Fan;Long Chen;Chaoqiang Zhang;Wei Tian;Dongpu Cao;
      Pages: 6260 - 6269
      Abstract: A persistent problem in the three-dimensional (3-D) reconstruction technique is to eliminate blank areas in the 3-D map, which commonly emerges after removing undesired objects, such as dynamic targets or occluded areas. This task is challenging for it is difficult to acquire the coherence between color and depth information, which are both lost for each pixel in the target region. Moreover, creating novel artifacts also needs to be avoided during the completion process. To address these problems, in this paper, we propose a collaborative method to complete the lost area in the color image and its corresponding depth map. In the proposed method, an examplar-based image inpainting technique combined with planarity knowledge is adopted to iteratively repair the texture and structure information. The color completion process provides candidates for plane-fitting on segmented superpixels. The depth filling step extracts image areas requiring reinpainting, which is defined by their gradient differences. The final 3-D map can then be reconstructed from both completed color and depth images. Experiments on real-world scenes demonstrate the success of our method in the completion of 3-D maps.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Velocity Synchronous Linear Chirplet Transform
    • Authors: Yunpeng Guan;Ming Liang;Dan-Sorin Necsulescu;
      Pages: 6270 - 6280
      Abstract: Linear transform has been widely used in time–frequency analysis of rotational machine vibration. However, the linear transform and its variants in current forms cannot be used to reliably analyze rotational machinery vibration signals under nonstationary conditions because of their smear effect and limited time variability in time–frequency resolution. As such, this paper proposes a new time–frequency method, named velocity synchronous linear chirplet transform (VSLCT). The proposed VSLCT is an extended version of the current linear transform. It can effectively alleviate the smear effect and can dynamically provide desirable time–frequency resolution in response to condition variations. The smearing problem is resolved by using linear chirplet bases with frequencies synchronous with shaft rotational velocity, and the time–frequency resolution is made responsive to signal condition changes using time-varying window lengths. To successfully implement the VSLCT, a kurtosis-guided approach is proposed to dynamically determine the two time-varying parameters, i.e., window length and normalized angle. Therefore, the VSLCT does not require the user to provide such parameters and hence avoids the subjectivity and bias of human judgment that is often time-consuming and knowledge-demanding. This method can also analyze normal monocomponent frequency-modulated signal.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A High-Gain Approach to Event-Triggered Control With Applications to Motor
           Systems
    • Authors: Dawei Shi;Jian Xue;Junzheng Wang;Yuan Huang;
      Pages: 6281 - 6291
      Abstract: In this paper, an event-triggered high-gain-observer-based output feedback control scheme is introduced by designing separate event-triggering conditions, which only rely on the measurable signals of the controlled system for the system outputs and the control signal, and the performance of the proposed control scheme is investigated. Quantitative relationships between the asymptotic upper bounds of the observation error and the parameters of the event-based sampler are developed to quantify the effect of event-based sampling. The theoretic analysis shows that the observation error can be guaranteed to be asymptotically bounded, and the closed-loop system can be guaranteed to be asymptotically stabilized. Comparative experiments are carried out on a dc torque motor system to validate the theoretic results, and the experimental results indicate that the proposed control strategy can achieve satisfactory control performance.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Fixed-Time Formation Control of Multirobot Systems: Design and Experiments
    • Authors: Chunyan Wang;Hilton Tnunay;Zongyu Zuo;Barry Lennox;Zhengtao Ding;
      Pages: 6292 - 6301
      Abstract: Time delays exist in network-connected systems. Especially for vision-based multirobot systems, time delays are diverse and complicated due to the communication network, camera latency, image processing, etc. At the same time, many tasks, such as searching and rescue, have timing requirement. This paper focuses on fixed-time formation control of multirobot systems subject to delay constraints. First, predictor-based state transformation is employed for each robot to deal with the input delay, and the uncertain terms remained in the transformed systems are carefully considered. Then, a couple of nonlinear fixed-time formation protocols are proposed for the multirobot systems with respectively undirected and directed topology, and the corresponding settling time is derived by using the Lyapunov functions. In particular, the upper-bound estimation of the formation settling time is explicitly given irrelevant to the initial conditions. Finally, the protocols are validated through a numerical simulation example and then implemented on an E-puck robots platform. Both simulation and experimental results demonstrate the effectiveness of the proposed formation protocols.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Overall Study of Frequency-Agile Mechanism of Varactor-Loaded λ/4
           Resonator for Designing Tunable Filter With Stable Wide Stopband
    • Authors: Jian-Xin Chen;Yu-Jing Zhang;Jing Cai;Yun-Li Li;Yong-Jie Yang;
      Pages: 6302 - 6310
      Abstract: This paper presents an overall investigation of the frequency-tuning mechanism of the varactor-loaded λ/4 stepped impedance resonator (SIR). The relationships between the tuning ranges of the resonant frequencies (fundamental frequency $(f_{1})$ and harmonics) and the basic parameters of the varactor-loaded SIR are theoretically analyzed and given in detail. It can be found that the loading location of the varactor and the SIR parameters (characteristic impedances and length ratio of the two sections) have significant effect on the frequency-tuning range. Benefiting from the discriminating responses of $f_{1}$ and $f_{3}$ (third harmonic) to the loading location of the varactor, $f_{1}$ can be well tuned as the varactor's capacitance changes while $f_{3}$ is fixed, when the varactor is loaded at the voltage-null point of $f_{3}$ on the λ/4 SIR. Thus, a stable wide stopband can be achieved due to the fixed $f_{3}$, which acts as the lowest spurious in the design of tunable filter. For demonstration, a second-order tunable filter with stable wide stopband and constant fractional bandwidth is implemented and measured. In the tuning process of the passband operating at $f_{1}$, the lowest spurious resulting from $f_{3}$ is immobile, which is always more than ${text{4}}f_{1}$. The simulated and measured results with good agreement are presented to verify the theoretical predictions.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Online Model-Based Thermal Prediction for Flexible Control of an
           Air-Cooled Hydrogenerator
    • Authors: Thomas Øyvang;Jonas Kristiansen Nøland;Gunne J. Hegglid;Bernt Lie;
      Pages: 6311 - 6320
      Abstract: The flexible generation of electrical energy is heavily dependent on hydropower. Advanced control systems may offer an enhanced operational security. During power system disturbances, a generator may need to operate beyond its limits to maintain a stable operation. This increased performance can be obtained if the total thermal capacity of the generator is exploited by applying optimal control theory in the automatic voltage regulator. A low-order model is required for online implementation and prediction of critical thermal stresses in the machine. Periodic extension of the generator capability diagram has been historically overlooked. In this paper, a thermal network for air-cooled hydrogenerators for use in real-time monitoring and optimal control is proposed and validated. The thermal model is extended with a heat exchanger model. The dynamic model is developed from an energy balance of the system and verified through finite-element method (FEM) simulations and temperature measurements in a case study. Transient simulation results of the online low-order model are in good agreement with measurements. Finally, a satisfactory simulator speed is obtained which confirms the feasibility of this approach in real-world applications.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Cumulative Canonical Correlation Analysis-Based Sensor Precision
           Degradation Detection Method
    • Authors: Zhiwen Chen;Chunhua Yang;Tao Peng;Hanbing Dan;Changgeng Li;Weihua Gui;
      Pages: 6321 - 6330
      Abstract: In practice, sensor precision degradation is ubiquitous and early detection of such a degradation is important for monitoring task. In this paper, a cumulative canonical correlation analysis (CCA) based sensor precision degradation detection method is presented in the Gaussian and non-Gaussian cases. At first, the fault sensitivity of the original CCA method to sensor precision degradation is theoretically analyzed. Then, the cumulative CCA-based method is proposed and delivers better fault detectability than the corresponding standard CCA-based method with respect to fault detection rate. For the non-Gaussian case, an efficient and practical applicable approach, referred as threshold learning approach, is proposed to set appropriate threshold based on available historical measurements. Finally, with the application to a real laboratorial continuous stirred tank heater plant, the feasibility and superiority of the proposed method are demonstrated by a comparison with the standard CCA-based and principal component analysis-based methods.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Information Fusion and Semi-Supervised Deep Learning Scheme for Diagnosing
           Gear Faults in Induction Machine Systems
    • Authors: Roozbeh Razavi-Far;Ehsan Hallaji;Maryam Farajzadeh-Zanjani;Mehrdad Saif;Shahin Hedayati Kia;Humberto Henao;Gérard-André Capolino;
      Pages: 6331 - 6342
      Abstract: There has been an increasing interest in the design of intelligent diagnostic systems for industrial applications. The key requirement in the design of practical diagnostic systems is the ability for decision making in high-dimensional feature spaces, where the prior knowledge about the system states in terms of labels is very limited. Moreover, the problem of diagnosing simultaneous defects is rarely addressed on real industrial applications. This paper aims to develop a semi-supervised deep-learning scheme for diagnosing multiple defects including simultaneous ones in a gearbox directly connected to an induction machine shaft. This scheme consists of two main modules: information fusion and decision making. The former integrates captured multiple sensory streams into a very high dimensional feature space. The latter uses a semi-supervised deep learning procedure to minimize the human interaction during the training and maximize the diagnostic efficiency. This scheme facilitates learning and diagnosing defects under harshest conditions 1) where only a few number of labeled samples are collected together with a large number of unlabeled samples, and 2) in a very high-dimensional feature space. Several state-of-the-art semi-supervised and supervised learners have also been included in the scheme, enabling a comparative experiment for diagnosing simultaneous defects.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Generalized Likelihood Ratio Test Based Approach for Stator-Fault
           Detection in a PWM Inverter-Fed Induction Motor Drive
    • Authors: Elhoussin Elbouchikhi;Yassine Amirat;Gilles Feld;Mohamed Benbouzid;
      Pages: 6343 - 6353
      Abstract: This paper proposes a new approach for the detection of stator faults in inverter-fed induction motor under closed-loop control. These faults, generally, start with interturn short circuit and can evolve to phase-to-phase or phase-to-ground faults, leading to stator currents unbalance. In the considered application, the stator windings are supplied by a static converter for the control of the speed and the rotor flux of the motor. The unbalance fault has been artificially created through additional resistance in series with one phase of the stator windings. The proposed diagnosis approach is based on the computation of the symmetrical components of the stator currents. The supply fundamental frequency and the three-phase phasors are estimated based on the maximum likelihood estimator. Then, the generalized likelihood ratio test is applied for unbalance fault detection. Simulation and experimental results on a 1.5-kW induction motor illustrate the effectiveness of the proposed approach, leading to an effective diagnosis procedure for stator faults in inverter-fed induction motor under steady state and closed-loop operation.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Optimal Design for a Portable NMR- and MRI-Based Multiphase Flow Meter
    • Authors: Mahmoud Meribout;
      Pages: 6354 - 6361
      Abstract: In this paper, an optimal design for nuclear magnetic resonance and magnetic resonance imaging based multiphase flow meter is presented. The overall apparatus consists of an electromagnetic coil surrounded by 12 rings of Halbach arrays of 12 magnets each. Both the coil and the magnets arrays were simultaneously and optimally designed using a three-dimensional (3-D) finite-element method (FEM) package and particle swarm optimization algorithm. The aim of the design is to uniformly prepolarize the hydrogen spins of the atoms composing the flowing fluid, with a predefined static magnetic field, before they enter into the measurement area within which they are homogenously polarized with a perpendicular ac magnetic field. Cheap and lightweight hardware are the other two design parameters of the design. Results of extensive 3-D simulations of the design indicate that an optimized and homogenous static magnetic field distribution could be achieved within an area of 40 mm diameter and 606 mm length. In addition, using a multiturn coil of 6 cm diameter and 2000 turns, an ac magnetic field of 13 mT amplitude and 112 ppm homogeneity could be achieved, which is enough to handle fluids flowing at speed of up to 2 m/s. Experimental validation, which was done using newly constructed two Halbach arrays of cuboid and trapezoid magnet elements, respectively, indicates a good match with FEM simulations.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Parallel Computing and SGD-Based DPMM For Soft Sensor Development With
           Large-Scale Semisupervised Data
    • Authors: Weiming Shao;Le Yao;Zhiqiang Ge;Zhihuan Song;
      Pages: 6362 - 6373
      Abstract: Soft sensors based on Gaussian mixture models (GMM) have been widely used in industrial process systems for modeling the nonlinearity, non-Gaussianity, and uncertainties. However, there are still some challenging issues in developing high-accuracy GMM-based soft sensors. First, labeled samples are usually scarce due to technical or economical limitations, causing traditional supervised GMM-based soft sensing methods fail to provide satisfactory performance. Second, tremendous amounts of unlabeled samples are gathered, nevertheless, how to fully exploit those unlabeled samples in terms of improving both the predictive accuracy and computational efficiency remains unresolved. In this paper, in order to deal with these issues, two computationally efficient soft sensing methods, namely the parallel computing-based semisupervised Dirichlet process mixture models (P–S$^2$DPMM) and stochastic gradient descent-based S$^2$DPMM (SGD–S$^2$DPMM), are proposed. The S$^2$DPMM is first developed to mine information contained in both labeled and unlabeled samples for predictive accuracy enhancement, and subsequently is extended to the P–S$^2$DPMM and SGD–S$^2$DPMM to handle large-scale process data with sufficient and limited computing resources, respectively. Two case studies are carried out on real-world industrial processes, and the results obtained demonstrate the effectiveness of the proposed methods.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Low-Cost, Tiny-Sized MEMS Hydrophone Sensor for Water Pipeline Leak
           Detection
    • Authors: Jinghui Xu;Kevin Tshun-Chuan Chai;Guoqiang Wu;Beibei Han;Eva Leong-Ching Wai;Wei Li;Jason Yeo;Edwin Nijhof;Yuandong Gu;
      Pages: 6374 - 6382
      Abstract: In this paper, we present an experimental investigation of a water pipeline leak detection system based on a low-cost, tiny-sized hydrophone sensor fabricated using the microelectromechanical system (MEMS) technologies. A 10 × 10 element arrayed MEMS hydrophone device with chip size of 3.5 × 3.5 mm$^2$ was used in the experiment. The hydrophone device is packaged with a customized on-board preamplification circuit using an acoustic transparent material. The overall package size of the MEMS hydrophone is $Phi$1.2 × 2.5 cm. The packaged MEMS hydrophone achieves an acoustic sensitivity of −180 dB (re: 1 V/$mu$Pa), a bandwidth from 10 Hz to 8 kHz, and a noise resolution of around 60 dB (re: 1 $mu text{Pa/}sqrt{text{Hz}}$) at 1 kHz. A section of ductile iron water pipeline with an internal diameter of 10 cm, wall thickness of 0.73 cm, and length of 30 m is constructed as the test bed for the water leak detection. Two different leak sizes with leak flow rates of about 30 and 180 L/min are designed along the pipe, which is pressurized at 3.2 bar. Analysis of the transient signals and spectrograms shows that the MEMS hydrophone can capture the key acoustic information of the water leak, i.e., identifying the leak and locating the leak position. The measurement results demonstrate the feasibility to construct an affordable, highly efficient, real-time, and permanent in-pipe pipeline health monitoring network based on the MEMS hydrophones due to their high performanc-, low cost, and tiny size.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Resolver-to-Digital Conversion Method Based on Third-Order Rational
           Fraction Polynomial Approximation for PMSM Control
    • Authors: Shuo Wang;Jinsong Kang;Michele Degano;Giampaolo Buticchi;
      Pages: 6383 - 6392
      Abstract: In this paper, a cost-effective and highly accurate resolver-to-digital conversion method is presented. The core of the idea is to apply a third-order rational fraction polynomial approximation for the conversion of sinusoidal signals into the pseudo linear signals, which are extended to the range 0°–360° in four quadrants. Then, the polynomial least squares method is used to achieve compensation to acquire the final angles. The presented method shows better performance in terms of accuracy and rapidity compared with the commercial available techniques in simulation results. This paper describes the implementation details of the proposed method and the way to incorporate it in digital signal processor-based permanent magnet synchronous motor drive system. Experimental tests under different conditions are carried out to verify the effectiveness for the proposed method. The obtained maximum error is about 0.0014° over 0°–360°, which can usually be ignored in most industrial applications.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Input-to-State Stability of Perturbed Nonlinear Systems With
           Event-Triggered Receding Horizon Control Scheme
    • Authors: Mengzhi Wang;Jian Sun;Jie Chen;
      Pages: 6393 - 6403
      Abstract: In this paper, input-to-state stability (ISS) properties of perturbed systems with event-triggered receding horizon control (RHC) schemes are studied. Two event-triggered control schemes, which are the event-triggered quasi-infinite RHC (EQRHC) and the event-triggered dual-mode RHC (EDRHC) strategies, respectively, are considered. In the EQRHC scheme, an optimal control problem (OCP) should be considered at triggering time and the event is triggered if the error between the actual system state and the optimal system state violating a threshold. While in the EDRHC strategy, an OCP is only solved outside the terminal region and a local control law will be used inside the terminal region. The corresponding event condition is redesigned based on if the system state enters the terminal region or not. The event-triggering condition outside the terminal region is the same with that of the EQRHC scheme and the event-triggering condition inside the terminal region is proposed based on the difference between the actual system state and the predictive system state. Sufficient conditions of feasibility are proposed and ISS properties of both event-triggered control schemes are studied, respectively. At last, numerical simulations show the validity of the proposed methods.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A 300 000-r/min Magnetically Levitated Reaction Wheel Demonstrator
    • Authors: Arda Tüysüz;Timon Achtnich;Christof Zwyssig;Johann W. Kolar;
      Pages: 6404 - 6407
      Abstract: Magnetic bearings can be used in reaction wheel systems to avoid several drawbacks of ball bearings, such as limited lifetime due to mechanical friction and lubricant monitoring/sealing requirements. Therefore, this letter discusses an electrical machine topology with integrated reaction wheel and magnetic bearings. The slotless/ironless structure, together with a new electromagnetic arrangement resulting in a shorter rotor than in earlier works, enables efficient operation at very high speeds, which in turn enables the miniaturization of the system. Measurements taken on a demonstrator prototype at 300 000 r/min show a significant increase of the feasible operational speed range compared to the state-of-the-art reaction wheels for small satellites, which typically run below 10 000 r/min.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Fast Estimation of Phase and Frequency for Single-Phase Grid Signal
    • Authors: Hafiz Ahmed;Sid-Ali Amamra;Ivan Salgado;
      Pages: 6408 - 6411
      Abstract: Accurate and fast estimation of single-phase grid voltage phase and frequency has the potential to improve the performances of various control and monitoring techniques used in electric power systems. This letter applies an adaptive sliding mode observer for frequency and phase estimation. The observer is simple, easy to tune, and suitable for real-time implementation. The proposed adaptive observer can be considered as an alternative to a phase-locked loop (PLL) with better performance. dSPACE-based experimental results are given to show the effectiveness and performance improvement of the proposed approach with respect to two other advanced PLL techniques, namely, pseudolinear enhanced PLL and second-order generalized integrator-frequency locked loop.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Complex Power Electronics Systems Modeling and Analysis
    • Authors: Seddik Bacha;Hong Li;Davis Montenegro-Martinez;
      Pages: 6412 - 6415
      Abstract: The papers in this special section focus on innovative research results and potentials in advanced modeling and analysis methods for power converters and systems proposed from academia to industry, and further promote their practical application in industrial electronics. Accurate and reliable modeling of power converters and electrical systems is a key issue for their integration and development in modern applications. However, nonlinear factors in power electronics introduced by their switching operation, performance demand and complex environments among others, make conventional modeling and analysis methods unreliable and even often-unfeasible. Modern engineering application requirements for power electronics and the future grid development demand a constant evolution of modeling and analysis techniques. On the other hand, novel modeling and analysis methods for power converters and systems, such as improved small-signal modeling and stability criterion, large-signal modeling and analysis methods, describing function methods, and so on, have been developed and proposed by authors from academia and industry to deal with the challenges mentioned above.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Generalized Single-Phase Harmonic State Space Modeling of the Modular
           Multilevel Converter With Zero-Sequence Voltage Compensation
    • Authors: Zigao Xu;Binbin Li;Shengbo Wang;Shiguang Zhang;Dianguo Xu;
      Pages: 6416 - 6426
      Abstract: The modular multilevel converter (MMC) has attracted extensive research in recent years. An appropriate model is necessary to analyze stability or to design MMC controllers. Several published MMC models have been derived in single-phase form to simplify the modeling mathematics. However, little attention is given to the zero-sequence voltage, which introduces coupling in the single-phase model and leads to significant error. In this paper, after revealing the mechanism behind the zero-sequence voltage, a more accurate generalized single-phase MMC model is proposed, which eliminates the zero-sequence voltage coupling effect and is linearized based on harmonic state space (HSS) theory to precisely characterize the internal harmonic features of MMC. A systematic HSS modeling process is presented for both open-loop and closed-loop conditions. And the proposed model is generalized as it can incorporate different control strategy by controller transfer function substitution. Hence it is valuable to analyze MMC stability and dynamics. Model effectiveness is verified by simulation results.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Exact Nonlinear Micromodeling for Fine-Grained Parallel EMT Simulation of
           MTDC Grid Interaction With Wind Farm
    • Authors: Ning Lin;Venkata Dinavahi;
      Pages: 6427 - 6436
      Abstract: Detailed high-order models of the insulated-gate bipolar transistor (IGBT) and the diode are rarely included in power converters for large-scale system-level electromagnetic transient (EMT) simulation on the CPU, due to the nonlinear characteristics albeit they are more accurate. The massively parallel architecture of the graphics processing unit (GPU) enables a lower computational burden by avoiding the computation of complex devices repetitively in a sequential manner and thus is utilized in this paper to simulate the wind farm-integrated multiterminal dc (MTdc) grid based on the modular multilevel converter (MMC). Fine-grained circuit partitioning is proposed so that the nonlinear switching elements are physically separated with the smallest circuit unit. By implementing these subsystems with the same attributes as a GPU program and computing it in a massively parallel manner, it is demonstrated that the GPU is able to achieve a significant speedup over multicore CPUs and its computation time incremental is much smaller when the MMC level scales up. The improved insight and accuracy of the proposed modeling methodology and the designed GPU program are validated at the system- and device-level by off-line commercial simulation tools.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Dynamic Aggregation Modeling of Grid-Connected Inverters Using
           Hamilton's-Action-Based Coherent Equivalence
    • Authors: Xiaoming Zha;Shuhan Liao;Meng Huang;Zezhou Yang;Jianjun Sun;
      Pages: 6437 - 6448
      Abstract: The high penetration of renewable energy generation (REG) systems influences the dynamics of power systems. Accurate transient simulations and dynamic models are indispensable for the research on the dynamic behavior of REG systems. A large-scale REG system consisting of numerous grid-connected inverters consumes a large amount of computation time, so a dynamic aggregated model is needed for efficient simulation. The aggregated model established by coherent equivalence fits the detailed model well, and thus it is widely used in the aggregation of large-scale dynamic systems. Presently, the key challenge of the application of the coherent-equivalence method is to identify inverters that have similar dynamic characteristics. The Hamilton principle expressed by Hamilton's action has a simple form and indicates the comprehensive dynamic characteristics of inverters. Thus, this paper proposes a coherent-equivalence method of inverters based on Hamilton's action. The proposed method is applied to a wind farm of 16 permanent magnet synchronous generator-based wind turbines for demonstration. Compared with the existing equivalence method without considering coherency, the proposed method shows advantages in effectiveness and accuracy.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Modeling and Analysis of Modular Multilevel Converter in DC Voltage
           Control Timescale
    • Authors: Jiabing Hu;Jianhang Zhu;Min Wan;
      Pages: 6449 - 6459
      Abstract: This paper presents a small-signal model of modular multilevel converter (MMC) based on the motion equation concept in the dc voltage control (DVC) timescale (around 10 Hz). The relations between the active/reactive powers and the phase/magnitude dynamics of the internal voltage vector are developed with considering the submodules (SMs) capacitor voltage ripple. With the proposed model, the stability mechanism of the DVC timescale in an MMC-HVdc system can be well interpreted with the equivalent inertia and damping coefficients. It is found that the fundamental frequency ripple in the capacitor voltage of SMs will result in new oscillation modes in DVC timescale when compared with the conventional two-level voltage source converter. Furthermore, the coupled relationship between the reactive power and phase dynamics of internal voltage is revealed, which has great effect on the system stability property. Then, comparative studies via eigenvalues analysis show the proposed model can hold the main behaviors of concern, and the correctness of the proposed model is verified by comparisons with detailed time-domain simulations and experimental tests. Finally a single MMC connected to infinite-bus grid is taken as an example to validate the feasibility of the proposed model for dynamics analysis.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Sequence Impedance Modeling and Stability Comparative Analysis of
           Voltage-Controlled VSGs and Current-Controlled VSGs
    • Authors: Wenhua Wu;Yandong Chen;Leming Zhou;An Luo;Xiaoping Zhou;Zhixing He;Ling Yang;Zhiwei Xie;Jinming Liu;Mingmin Zhang;
      Pages: 6460 - 6472
      Abstract: The premise that the virtual synchronous generator (VSG) can actively support the weak grid is that the VSG can operate stably. In this paper, the small-signal sequence impedance models of the voltage-controlled VSG and the current-controlled VSG are built and the sequence impedance characteristics of these two types of VSGs are compared and analyzed. The sequence impedance of the voltage-controlled VSG, being consistent with the grid impedance characteristics, is generally inductive. By contrast, the sequence impedance of the current-controlled VSG is mainly negative impedance in the middle- and high-frequency area and the impedance amplitude is quite low. Based on the built sequence impedance models and the impedance stability criterion, the influence of the weakness of the grid on the stability of these two types of VSG grid-connected system is analyzed. The results of stability analysis show that the current-controlled VSG is prone to instability while the voltage-controlled VSG remains stable. Therefore, the voltage-controlled VSG is more suitable than the current-controlled VSG for grid-connected renewable energy generation in an ultraweak grid from the point of view of system stability. Finally, experiment results validate the stability analysis.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Design-Oriented Transient Stability Analysis of Grid-Connected Converters
           With Power Synchronization Control
    • Authors: Heng Wu;Xiongfei Wang;
      Pages: 6473 - 6482
      Abstract: The power synchronization control (PSC) has been increasingly used with voltage-source converters (VSCs) connected to the weak ac grid. This paper presents an in-depth analysis on the transient stability of the PSC-VSC by means of the phase portrait. It is revealed that the PSC-VSC will maintain synchronization with the grid as long as there are equilibrium points after the transient disturbance. In contrast, during grid faults without any equilibrium points, the critical-clearing angle (CCA) for the PSC-VSC is identified, which is found equal to the power angle of the unstable equilibrium point of the postfault operation. This fixed CCA facilitates the design of power system protection. Moreover, it is also found that the PSC-VSC can still resynchronize with the grid after around one cycle of oscillation, even if the fault-clearing angle is beyond the CCA. This feature reduces the risk of system collapse caused by the delayed fault clearance. These findings are corroborated by simulations and experimental tests.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Stability Analysis of PV Generators With Consideration of P&O-Based Power
           Control
    • Authors: Yanghong Xia;Wei Wei;Miao Yu;Peng Wang;
      Pages: 6483 - 6492
      Abstract: Photovoltaic (PV) generators have continuously increased in recent years, whose power is usually controlled through the perturbation and observation (P&O) method. In essence, the P&O method is nonlinear and discontinuous. Hence, the conventional small-signal stability analysis is not suitable anymore when the influence of the P&O-based power control is considered. Focusing on this problem, this paper adopts the nonlinear describing function (DF) method to conduct the accurate stability analysis of PV generators with consideration of P&O-based power control. The detailed procedures about the DF method are introduced, and then the related influence factors like perturbation size, filters, and so on are analyzed quantitatively. Furthermore, the comparison with the conventional stability analysis methods is made, which suggests that the DF method can effectively enhance the accuracy of the stability analysis. All the conclusions are verified by the real-time hardware-in-loop tests.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Divided DQ Small-Signal Model: A New Perspective for the Stability
           Analysis of Three-Phase Grid-Tied Inverters
    • Authors: Zhikang Shuai;Yang Li;Weimin Wu;Chunming Tu;An Luo;Z. John Shen;
      Pages: 6493 - 6504
      Abstract: The instability issues of the three-phase grid-tied inverters are major concerns in the distributed generated systems. However, due to the coupling effects in dq frame, the instability mechanisms of the three-phase inverters have not yet been clearly revealed. This paper presents a divided dq small-signal model of the grid-tied inverter in dq frame. The specific expressions of a small-signal output admittance of the inverter are investigated based on the proposed model, which can reveal the influencing mechanism of coupling effects and phase-locked loop (PLL) on the stability of the inverter. Then, a stability analysis method based on the divided dq small-signal model is proposed, by which the procedure of checking the stability of the grid-tied inverters with strong/weak grid is executed step by step, and it could be helpful for the system parameters design. Furthermore, the stability of the multiparalleled inverter system is also studied, and it indicates that as the number of the paralleled inverters increases, the parameters of PLL could be adjusted for a stable operation. The theoretical stability analysis results are verified by simulations and experiments.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Multivariable High-Frequency Input-Admittance of Grid-Connected
           Converters: Modeling, Validation, and Implications on Stability
    • Authors: Francisco D. Freijedo;Marc Ferrer;Drazen Dujic;
      Pages: 6505 - 6515
      Abstract: Modern grids are facing a massive integration of power electronics devices, usually associated to instability issues. In order to assess the likelihood and severity of harmonic instability in the high-frequency region, this paper develops a multivariable input-admittance model that accurately reflects the following aspects: 1) the discrete controller frequencies are defined inside a spectrum region limited by the Nyquist frequency and 2) the physical system aliases are transformed into lower frequency component inside the discrete controller. The proposed model shows that dynamic interactions are not theoretically band-limited; however, the control action tends to be strongly limited in a low-frequency range, due to the natural low-pass filter behavior of acquisition and modulation blocks. This is reflected in a reduced resistive part (either positive or negative) of the input-admittance in the high-frequency range. More specifically, considering the input-admittance passivity criterion, the excursions into the nonpassive area are very smooth at high frequencies, where the input-admittance is well-described by simply its inductive filter. Comprehensive experiments are conducted on a lab scale prototype, which includes measurements beyond the Nyquist frequency and alias identification. The experimental results well-match the theoretical model.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Droop-Controlled Rectifiers That Continuously Take Part in Grid Regulation
    • Authors: Qing-Chang Zhong;Zijun Lyu;
      Pages: 6516 - 6526
      Abstract: In this paper, a generic framework for a rectifier to continuously take part in the regulation of grid voltage and frequency is proposed. It can automatically change the power consumed to support the grid, without affecting the normal operation of the load. Such a rectifier has a built-in storage port, in addition to the normal ac and dc ports. The flexibility required by the ac port to support the grid is provided by the storage port without affecting the dc port. The grid support of the ac port is achieved through the recently proposed universal droop controller (UDC). A dc-bus voltage controller cascaded to the UDC is proposed to regulate the dc-bus voltage of the storage port within a wide range so as to provide the flexibility needed, while the dc-port voltage is maintained constant. An illustrative example is presented with the recently proposed $theta$-converter, which consists of three ports with only four switches. Experimental results are provided to verify the capability of the rectifier to regulate the grid voltage and frequency without affecting the load.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Control of Direct Voltage Regulated Active DC-Link Capacitance Reduction
           Circuits to Allow Plug-and-Play Operation
    • Authors: Alexei Mutovkin;Vladimir Yuhimenko;Martin Mellincovsky;Shmuel Schacham;Alon Kuperman;
      Pages: 6527 - 6537
      Abstract: A novel method for controlling direct voltage regulated active dc-link capacitance reduction circuits (ACRC) is proposed in this paper. Instead of forcing the dc-link voltage of the power conversion system to follow a constant reference, the ACRC imposes dc-bus voltage in proportion to the integral of its input current. Consequently, it resembles an adjustable value capacitor from the dc-link side. Therefore, as opposed to existing control strategies, the proposed method simultaneously allows the dc-link voltage to reflect the power balance of the system and the pulsating power component to be diverted into significantly reduced auxiliary capacitance via a bidirectional dc–dc converter. As a result, replacing bulk dc-link capacitance by the proposed circuitry does not require any modification of existing grid-connected power conversion system controllers, thus allowing plug-and-play operation. The proposed approach is validated by application to a commercial power factor correction front end by both simulations and experiments.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Investigation and Modeling of Combined Feedforward and Feedback Control
           Schemes to Improve the Performance of Differential Mode Active EMI Filters
           in AC–DC Power Converters
    • Authors: Rajib Goswami;Shuo Wang;
      Pages: 6538 - 6548
      Abstract: In this paper, the models of active differential mode electromagnetic interference input filters for ac–dc converters are first investigated. The models are developed for active filters with single feedback (FB) and single feedforward (FF) configurations, which include an active filter, passive filters, and the noise model for a converter. To increase the gain of the single active filter, the models for FB–FF, FF–FB, parallel FB, and series feedback (SFB) configurations are developed and investigated. Loop gains and insertion gains for all of these configurations are derived and compared. Stability has been analyzed based on the loop gains and a compensation technique is introduced to ensure stability. Based on the comparison among all these control configurations, it has been found that the SFB configuration can achieve the highest noise reduction. The loop gains and insertion gains of an active filter prototype with the SFB configuration are measured using a network analyzer to validate the developed model and compensation technique. Finally, spectrum measurements with a commercial boost power factor correction ac–dc converter have been conducted to verify the developed modeling and control techniques as well as the predicted performance for the SFB configuration.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • A Design Methodology of Multiresonant Controllers for High Performance 400
           Hz Ground Power Units
    • Authors: Felix Rojas;Roberto Cardenas;Jon Clare;Matias Diaz;Javier Pereda;Ralph Kennel;
      Pages: 6549 - 6559
      Abstract: In aerospace applications, a ground power unit has to provide balanced and sinusoidal $text{400},text{Hz}$ phase-to-neutral voltages to unbalanced and nonlinear single-phase loads. Compensation of high-order harmonics is complex, as the ratio between the sampling frequency and compensated harmonics can be very small. Thus, multiple superimposed resonant controllers or proportional-integral (PI) nested controllers in multiple $dq$ frames are not good alternatives. The first approach cannot ensure stability, while the second cannot track the sinusoidal zero-sequence components typically present in unbalanced systems, and unattainably high bandwidth at the inner current control loop is typically required. In this paper, a simple methodology for designing a single-loop, multiple resonant controller for simultaneous mitigation of several high-order harmonics, ensuring stability, is presented. Experimental results, based on a 6 kW four-leg neutral point clamped converter, validate the proposed controller design, showing excellent steady-state and transient performance.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Modeling and Hierarchical Structure Based Model Predictive Control of
           Cascaded Flying Capacitor Bridge Multilevel Converter for Active Front-End
           Rectifier in Solid-State Transformer
    • Authors: Si-Hwan Kim;Yeong-Hyeok Jang;Rae-Young Kim;
      Pages: 6560 - 6569
      Abstract: This paper introduces modeling and control of a cascaded flying capacitor bridge (CFCB) multilevel converter for a solid-state transformer. The finite control set-model predictive control (FCS-MPC) is easy and simple to implement for many applications. However, the computational complexity increases with the increase in the number of switches. Furthermore, as the number of control variables increases, the weighting factors also increase. Thus, it is difficult to apply to a system with a large number of switches and variables to be controlled similar to a CFCB multilevel converter. In this paper, the proposed method divides variables such as current, dc-link voltage, and flying capacitor voltage into layers. The proposed method reduces the number of states to be considered in the control, which shortens the computational time and simplifies expansion of the flying capacitor bridge. In addition, since weighting factors are not used, there is no tradeoff between current quality and voltage quality, and there is no difficulty in selecting weighting factors. Algorithms that include a method for compensating for the distortion caused by the delay of the digital control system are also described. The effectiveness of the proposed method is verified via experiments using a two-cell CFCB multilevel converter.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Reliability Analysis on Power Converter of Switched Reluctance Machine
           System Under Different Control Strategies
    • Authors: Shuai Xu;Hao Chen;Feng Dong;Jian Yang;
      Pages: 6570 - 6580
      Abstract: In this paper, a novel reliability assessment scheme is presented to achieve the optimal selection of control strategies for switched reluctance machine system from the perspective of reliability. To begin with, a combination model of k-out-of-n:G model and Markov model is proposed to lower the complexity and enhance the accuracy of system-level reliability assessment. As for the component-level reliability assessment, the three-dimensional coupled thermal circuit model of power converter is built to achieve the precise and fast prediction of junction temperature that is necessary for calculation of failure rate. Then the static and dynamic reliability analyses are carried out under voltage chopping control (VCC), current chopping control (CCC), and angle position control (APC) strategies, which indicates that the implementation scope of the APC strategy should be broadened. Compared with the VCC strategy, the CCC strategy is strongly recommended even if current sensors boost the extra failure rate. Besides, the increase in redundancy levels on power converter is certified as the most powerful measure for reliability enhancement of the SRM system and the most cost-effective redundancy level can also be quantitatively obtained. The experiments of fault-tolerance capability and thermal stress indirectly verify the validity of reliability analysis.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • An FPGA-Based IGBT Behavioral Model With High Transient Resolution for
           Real-Time Simulation of Power Electronic Circuits
    • Authors: Hao Bai;Chen Liu;Akshay Kumar Rathore;Damien Paire;Fei Gao;
      Pages: 6581 - 6591
      Abstract: This paper presents a novel insulated gate bipolar transistor (IGBT) behavioral model on the field programmable gate array (FPGA), which is suitable for the real-time simulation of fast transients in power electronics circuits. In this model, the static and dynamic behaviors of the IGBT switch are described and modeled separately. The static IGBT model is represented by the saturation region of output characteristic and is a part of the circuit network model. The dynamic IGBT model is combined with the static one to describe the fast switching transient behaviors by using the IGBT equivalent circuit model. The presented dynamic model in this paper does not involve any iterative solving algorithm and can be designed with highly pipelined structures on FPGA. Therefore, the IGBT switching transient waveforms can be generated precisely with a 5 ns resolution. The proposed model is tested with two cases—a four-phase floating interleaved boost converter and a three-phase five-level modular multilevel converter. The effectiveness and accuracy of the model are validated by comparing the real-time simulation results with offline simulation software.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Extended Harmonics Based Phase Tracking for Synchronous Rectification in
           CLLC Converters
    • Authors: Arun Sankar;Ayan Mallik;Alireza Khaligh;
      Pages: 6592 - 6603
      Abstract: Synchronous rectification (SR) is one of the well-known methods to reduce the conduction losses by replacing the power diodes. The control of SR requires the phase information of the device current. In this paper, a novel extended harmonics approximation modeling approach is introduced for CLLC resonant converters to estimate the phase of its secondary side current accurately. Conventionally, the first harmonic approximation (FHA) is used to model any resonant converter; however, FHA works more accurately near the resonant frequency operation. But in case of a set of unmatched LC tank parameters in the primary and secondary side of a CLLC converter, there is no uniquely defined resonant frequency, which reduces the accuracy of the FHA model. Unlike FHA-based approach, our proposed modeling considers the effects of other odd order harmonics present in the square wave voltage waveform towards determining the zero-crossing instant or phase information of the resonant currents. The proposed concept is verified through experimental results obtained at 3.3-kW load condition, and the converter efficiency is improved by 1.8% with the proposed phase tracking technique, compared to FHA modeling approach.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Nonlinear Modeling and Harmonic Analysis of Magnetic Resonant WPT System
           Based on Equivalent Small Parameter Method
    • Authors: Yanfeng Chen;Wenxun Xiao;Zhipeng Guan;Bo Zhang;Dongyuan Qiu;Meiyu Wu;
      Pages: 6604 - 6612
      Abstract: The magnetic resonant wireless power transfer (WPT) system with a class E inverter has wide application in mid-range power transmission, especially for several megahertz scenario. However, it is cumbersome for the existing modeling and analysis methods to obtain the analytical solution to the system variables, which limits the evaluation of system characteristic. This paper proposes a nonlinear mathematical model for the WPT system with a class E inverter. The equivalent small parameter method (ESPM) is first adopted to solve the proposed six-order nonlinear model, and symbolic-form steady-state periodic solutions are yielded. During the whole solving process, only three iteration steps are needed for the proposed method. Compared with other existing modeling and analysis methods, the symbolic periodic results acquired by the ESPM exhibit sufficient accuracy by virtue of the combination of more higher harmonics. Meanwhile, the calculation complexity is simplified remarkably. Simulation and available experiments validate the effectiveness and accuracy of the proposed method.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
  • Phase Current Digital Analysis of Power Converter for Freewheeling Diode
           Fault Diagnosis on Switched Reluctance Motor Drive
    • Authors: Hao Chen;Guoqiang Han;Xianqiang Shi;Jinlong Dong;
      Pages: 6613 - 6624
      Abstract: Power converter is critical but prone to be failure in switched reluctance motor (SRM) drives. The open- and short-circuit fault characteristics of freewheeling diode in asymmetric bridge power converter are analyzed in details. Based on logic judgment, four online fault diagnostic methods with digital phase current analysis of power converter are proposed in this paper. The fault features are extracted by analyzing the relationship between chopping signal and the current information from some special positions. The four fault diagnostic methods are carried out according to the current obtained by detecting dc bus current and the lower freewheeling bus current, the chopped bus current, the upper excitation bus current and lower freewheeling bus current, the lower excitation bus current, and dc bus current, respectively. Comparisons between the four diagnostic methods are conducted. Simulations and experiments on a 12/8 SRM validate the effectiveness of the proposed methods.
      PubDate: Aug. 2019
      Issue No: Vol. 66, No. 8 (2019)
       
 
 
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