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  Subjects -> ELECTRONICS (Total: 184 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: 6)
Advances in Electronics     Open Access   (Followers: 79)
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: 318)
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: 267)
Edu Elektrika Journal     Open Access   (Followers: 1)
Electrica     Open Access  
Electronic Design     Partially Free   (Followers: 106)
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: 93)
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: 197)
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: 67)
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: 20)
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: 70)
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: 25)
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: 4)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 6)
International Journal of Control     Hybrid Journal   (Followers: 11)
International Journal of Electronics     Hybrid Journal   (Followers: 7)
International Journal of Electronics and Telecommunications     Open Access   (Followers: 13)
International Journal of Granular Computing, Rough Sets and Intelligent Systems     Hybrid Journal   (Followers: 2)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Hybrid Intelligence     Hybrid Journal  
International Journal of Image, Graphics and Signal Processing     Open Access   (Followers: 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: 25)
Journal of Electrical Bioimpedance     Open Access  
Journal of Electrical Bioimpedance     Open Access   (Followers: 2)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 7)
Journal of Electrical, Electronics and Informatics     Open Access  
Journal of Electromagnetic Analysis and Applications     Open Access   (Followers: 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   (Followers: 2)
Journal of Field Robotics     Hybrid Journal   (Followers: 3)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 169)
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: 29)
Journal of Power Electronics & Power Systems     Full-text available via subscription   (Followers: 11)
Journal of Semiconductors     Full-text available via subscription   (Followers: 5)
Journal of Sensors     Open Access   (Followers: 26)
Journal of Signal and Information Processing     Open Access   (Followers: 9)
Jurnal ELTIKOM : Jurnal Teknik Elektro, Teknologi Informasi dan Komputer     Open Access  
Jurnal Rekayasa Elektrika     Open Access  
Jurnal Teknik Elektro     Open Access  
Jurnal Teknologi Elektro     Open Access  
Kinetik : Game Technology, Information System, Computer Network, Computing, Electronics, and Control     Open Access  
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Magnetics Letters, IEEE     Hybrid Journal   (Followers: 7)
Majalah Ilmiah Teknologi Elektro : Journal of Electrical Technology     Open Access   (Followers: 2)
Metrology and Measurement Systems     Open Access   (Followers: 5)
Microelectronics and Solid State Electronics     Open Access   (Followers: 19)
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)
Revue Méditerranéenne des Télécommunications     Open Access  
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 54)
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
IEEE Journal of Emerging and Selected Topics in Power Electronics
Journal Prestige (SJR): 1.657
Citation Impact (citeScore): 7
Number of Followers: 46  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2168-6777 - ISSN (Online) 2168-6785
Published by IEEE Homepage  [191 journals]
  • IEEE Journal of Emerging and Selected Topics in Power Electronics
    • 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: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • IEEE Power 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: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Special Section on Resonant and Soft-Switching Techniques With Wide
           Bandgap Devices
    • Authors: Mark Dehong Xu;Gerry Moschopoulos;
      Pages: 606 - 608
      Abstract: The development of wide bandgap (WBG) devices in recent years, such as silicon carbide (SiC) and gallium nitride (GaN) power devices, has resulted in power converters with power densities and efficiencies that are not possible with traditional silicon (Si) devices. While the fast switching speed of WBG devices enables higher converter efficiency and power density, a number of issues are created such as increased sensitivity to parasitics, EMI noise, high voltage and current overshoot and ringing, and heat centralization in semiconductor devices. Resonant and soft-switching techniques can be effective in resolving these issues and allow even higher power densities and efficiencies to be achieved.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • An Isolated Phase-Shift-Controlled Quasi-Switched-Capacitor DC/DC
           Converter With Gallium Nitride Devices
    • Authors: Boxue Hu;John Alex Brothers;Xuan Zhang;Lixing Fu;Yazan M. Alsmadi;Jin Wang;
      Pages: 609 - 621
      Abstract: This paper presents the circuit analysis and design guidelines of an isolated voltage-fed phase-shift-controlled quasi switched-capacitor (QSC) dc/dc circuit. The circuit under study is friendly toward the adoption of gallium nitride (GaN) devices by reducing the voltage stress on the devices and mitigating the circulating energy in the circuit. Compared to the conventional halfand full-bridge-based circuits, the phase-shift-controlled QSC circuit can reduce the voltage stress of high-voltage-side devices to 2/3 of the dc bus voltage. The reduced voltage stress can greatly extend the short-circuit withstand time of GaN devices and, thus, improve the reliability of the overall circuit. In a manner similar to a dual-active-bridge circuit, the circuit under study has low circulating energy since it achieves soft switching operation merely with the energy stored in the transformer's leakage inductance. In this paper, the operation principle, soft switching analysis, and design guidelines of the circuit are presented. A 1-kW, 400-48-V, 500-kHz switching frequency prototype with GaN devices was built and tested to verify the circuit analysis.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Ultraefficient Voltage Doubler Based on a GaN Resonant Switched-Capacitor
           Converter
    • Authors: Miroslav Vasić;Diego Serrano;Victor Toral;Pedro Alou;Jesus A. Oliver;Jose A. Cobos;
      Pages: 622 - 635
      Abstract: In this paper, we present a highly efficient and compact voltage doubler based on a resonant switched-capacitor converter implemented with GaN FETs. Two possible approaches for its implementation are analyzed and compared. In the first approach, the resonant inductor is placed in series with a resonant capacitor, conducting a sinusoidal current, while in the second, it is placed in series with the input source, conducting rectified sinusoidal current. Both resonant converters have the same voltage gain, and although the change in the position of the resonant inductor is, at the first glance, of minor importance, the analysis and results show that it has huge impact on the capability to achieve zero-voltage switching (ZVS) transitions at low output power. The experimental results clearly show that at low loads when the resonant inductor is in series with the resonant capacitor, the switching frequency can be significantly higher than the resonant frequency and that it is, practically, impossible to achieve ZVS transitions, forcing the implementation of cycle skipping. The prototype implemented for the experiments can provide up to 4.5-kW losing between 20 and 22 W. In the case of light load (500 W), the power losses were only 2-3 W. Its power density is higher than 65 kW/dm3. The same resonant converter was tested with Si CoolMOS devices as well and the impact of the semiconductor technology on the overall power losses was verified. Due to higher Coss capacitance, the Si-based converter has 40% higher power losses at full power than its GaN-based counterpart. The components of the GaN-based converter occupy only 65 cm3, which opens a possibility to obtain a design with extremely high power density.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • PWM Plus Phase-Shift-Modulated Three-Port Three-Level Soft-Switching
           Converter Using GaN Switches for Photovoltaic Applications
    • Authors: Hadi Moradisizkoohi;Nour Elsayad;Mehdi Shojaie;Osama A. Mohammed;
      Pages: 636 - 652
      Abstract: Gallium nitride (GaN) high-electron mobility transistors (HEMTs) are a promising technology for high-efficiency and high-power density applications. In this paper, a stacked three-port three-level converter (STPTLC) using GaN switches is proposed for interfacing the renewable energy sources (RESs) with load for applications that the presence of energy storage device is necessary. Derived from the asymmetrical bidirectional half-bridge (ABHB) converter, the proposed converter presents valuable advantages in terms of simple control scheme, extended soft-switching over a wide range of operating conditions, and reduced voltage stress across switches. The soft-switching for all switches at turn-on instant is guaranteed, thanks to the active clamp configuration, resulting in the high-efficiency performance. The pulsewidth-modulation (PWM) plus phase-shift control technique paves the way for decoupled regulation of the output voltage and power by presenting two control freedoms, which allows the input voltage to vary in a wide range. To diminish the current stress of switches and minimize the conduction loss, the root-mean-square (rms) current of inductance and the boundary condition of the phase-shift controller in different operation cases are studied. Finally, the experimental results of a 1-kW, 100-kHz prototype of STPTLC using GaN switches are given to confirm the validity of the proposed concept.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • High-Frequency Three-Phase Interleaved LLC Resonant Converter With GaN
           Devices and Integrated Planar Magnetics
    • Authors: Chao Fei;Rimon Gadelrab;Qiang Li;Fred C. Lee;
      Pages: 653 - 663
      Abstract: The LLC converter is deemed the most widely used topology as dc/dc converter in server and telecom applications. To increase the output power and reduce the input and output current ripples, three-phase interleaved LLC converter is becoming more and more popular. It has been demonstrated that three interleaved LLC converter can achieve further efficiency improvement at the 3-kW power level. However, the magnetic components for multiphase LLC converter are complex, bulky, and difficult to manufacture in a cost-effective manner. In this paper, a high-frequency gallium nitride (GaN)-based three-phase LLC converter is employed to address these aforementioned challenges. With GaN operating at 1 MHz, all magnetic components, namely, three inductors and three transformers, can be integrated into one common structure while all magnetic windings implemented in a compact four-layer PCB with 3-oz copper. The proposed structure can be easily manufactured cost-effectively in high quality. Furthermore, shielding techniques for full-bridge secondary have been investigated, and additional two-layer shielding has been integrated to reduce common-mode noise. A 1-MHz 3-kW 400 V/48 V three-phase LLC converter is demonstrated, and the peak efficiency of 97.7% and power density of 600 W/in3 (37 kW/L) are achieved.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • High-Efficiency High-Bandwidth Four-Quadrant Fully Digitally Controlled
           GaN-Based Tracking Power Supply System for Linear Power Amplifiers
    • Authors: Vladan Ž. Lazarević;Iñigo Zubitur;Miroslav Vasić;Jesús A. Oliver;Pedro Alou;Gregory Patchin;Jens Eltze;José A. Cobos;
      Pages: 664 - 678
      Abstract: The ever-rising demands for a high efficiency and high power density in the power electronics market are motivating an intensive research in the area of wide bandgap (WBG) devices, with enhancement-mode gallium-nitride (GaN) highelectron-mobility transistors as the main representatives. Compared to the conventional silicon devices with the same voltage rating and ON-state resistance, the parasitic capacitances of GaN transistors are smaller up to 10 times. Although their turn-off energy is very small, for the high switching speeds, zero-voltage switching is preferable to avoid the turn-on power losses, especially in the application where the devices operate at megahertz switching frequencies and where the blocking voltages are high. This is also very important from the thermal point of view, due to the poor junction to ambient thermal impedance of the packaging, in order to avoid high junction temperatures. Moreover, for a successful design of a power converter, the magnetic materials optimized for the high-frequency range are a must, with a manganese-zinc ferrites as the most promising solution. In this paper, an 8-W, 1-MHz switching frequency fully digitally controllable bipolar tracking power supply with a 100-kHz small-signal bandwidth, the tracking speeds up to 2 V/μs, and the maximum efficiency beyond 94% is shown, where a symbiosis of WBG devices and the newest generation high-frequency magnetic materials manifests the clear benefits.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • $C_{text{oss}}$+ -Losses+in+Soft-Switching+GaN-on-Si+Power+HEMTs&rft.title=IEEE+Journal+of+Emerging+and+Selected+Topics+in+Power+Electronics&rft.issn=2168-6777&rft.date=2019&rft.volume=7&rft.spage=679&rft.epage=694&rft.aulast=Häberlen;&rft.aufirst=Mattia&rft.au=Mattia+Guacci;Morris+Heller;Dominik+Neumayr;Dominik+Bortis;Johann+W.+Kolar;Gerald+Deboy;Clemens+Ostermaier;Oliver+Häberlen;">On the Origin of the $C_{text{oss}}$ -Losses in Soft-Switching GaN-on-Si
           Power HEMTs
    • Authors: Mattia Guacci;Morris Heller;Dominik Neumayr;Dominik Bortis;Johann W. Kolar;Gerald Deboy;Clemens Ostermaier;Oliver Häberlen;
      Pages: 679 - 694
      Abstract: The unprecedented performance potential of gallium nitride-on-silicon (GaN-on-Si) high electron mobility transistors (HEMTs) is seen as the key enabler for the design of power converters featuring extreme power density figures, as demanded in next-generation power electronics applications. However, unexpected loss mechanisms, i.e. dynamic Rds,on phenomena and Coss-losses, are appearing in currently available GaN transistors and are compromising their operation. In this paper, measurements of Coss-losses are performed in a dedicated calorimetric measurement setup and, through a systematic approach, the root cause of the loss mechanism is potentially identified. Afterward, with the essential support of a manufacturer of power semiconductors, a novel transistor, featuring an enhanced multilayer III-N buffer, is developed according to the acquired knowledge. A significant reduction in terms of Coss-losses, i.e. of soft-switching losses, and the absence of dynamic Rds,on phenomena are verified experimentally on the new device. These achievements enable a significant performance improvement for future soft-switching power converters featuring GaN-on-Si HEMTs.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Circuit Design Considerations for Reducing Parasitic Effects on GaN-Based
           1-MHz High-Power-Density High-Step-Up/Down Isolated Resonant Converters
    • Authors: Xiaonan Zhao;Cheng-Wei Chen;Jih-Sheng Lai;Oscar Yu;
      Pages: 695 - 705
      Abstract: With the availability of wide bandgap devices, the power converters can now potentially operate at megahertz (MHz) or higher frequencies while achieving ultrahigh efficiency. Such a high-frequency switching is particularly important for isolated converters to reduce the size of the passive components, achieve high power-density, and reduce costs. However, unlike the conventional kilohertz switching, in MHz switching, the parasitic components will significantly affect the circuit operation. These effects are compounded by high-ratio step-up or step-down isolated converters because the parasitic capacitances/inductances are squared times the turns' ratio of the transformer when reflecting from high-voltage (HV) to low-voltage (LV) side to LV/HV side. In this paper, a highstep-up series resonant converter is used as a design example to explore the effects of parasitic inductances induced from the LV side and parasitic capacitances induced from the HV side on the circuit operation under MHz switching conditions. Afterward, the printed circuit board (PCB) layout and the planar transformer are optimized through the finite-element method to minimize the parasitic effects. Finally, a 1-MHz, 38-V/380-V, 300W resonant converter prototypes are built and compared to verify the design optimization.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A High-Frequency Inverter for Variable-Load Operation
    • Authors: Weston D. Braun;David J. Perreault;
      Pages: 706 - 721
      Abstract: This paper presents a new inverter architecture suitable for driving widely varying load impedances at high frequency (HF, 3-30 MHz) and above. We present the underlying theory and design considerations for the proposed architecture along with a physical prototype and efficiency optimizing controller. The HF variable-load inverter (HFVLI) architecture comprises two HF inverters with independently controllable amplitude and phase connected together and to the load via a lossless power combining network, implemented here as an immittance converter. By controlling the amplitudes and relative phase of the two constituent inverters, the loading seen by each constituent inverter can be kept in a desirable range even for wide variations in load impedance. This allows for the use of highly efficient zero-voltage switching inverters that would otherwise be precluded or limited in applications presenting wide impedance ranges, such as wireless power transfer and RF plasma generation. The prototype HFVLI system demonstrates the benefits of the proposed approach. It operates at 13.56 MHz and can supply a maximum output power of 1 kW into a 21.8 + 0.3j load at an efficiency of 95.4% and is able to drive a wide range of capacitive and inductive loads at high power with high efficiency.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Zero-Voltage-Switching SiC-MOSFET Three-Phase Four-Wire Back-to-Back
           Converter
    • Authors: Keyan Shi;An Zhao;Jinyi Deng;Dehong Xu;
      Pages: 722 - 735
      Abstract: This paper proposes a novel zero-voltage-switching (ZVS) three-phase four-wire back-to-back (BTB) converter topology and its ZVS sinusoidal pulsewidth modulation (ZVS-SPWM) scheme. With the proposed ZVS-SPWM scheme, all the main switches in both the rectifier side and inverter side and the auxiliary switch can realize ZVS turn on with only one auxiliary circuit. In addition, the auxiliary switch only needs to operate once in each switching period, which can cut down an extra loss of the auxiliary circuit. The operation stage analysis is introduced, and the ZVS condition for the switches is derived. The ZVS BTB converter is investigated with respect to both balanced and unbalanced load conditions. In additon, the soft-switching parameter design guideline is discussed. Finally, the proposed ZVS BTB converter and its ZVS-SPWM scheme are verified on a 9-kW prototype with the SiC-MOSFET device.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Voltage-Edge-Rate-Limiting Soft-Switching Inverter Based on Auxiliary
           Resonant Pole
    • Authors: Minyu Cai;Oleg Wasynczuk;Maryam Saeedifard;
      Pages: 736 - 744
      Abstract: To increase switching frequencies while limiting switching losses in voltage-source inverters, power switches have been made significantly faster with achievable switching times now less than 100 ns. However, faster switches generate larger inverter output voltage edge rates (dv/dt) and result in deleterious effects in variable-speed drive systems including transient overvoltages at motor terminals, electromagnetic interference, and bearing failures due to microarcs. A common approach for limiting peak dv/dt involves using a dv/dt filter. However, the dv/dt filter introduces extra power losses and increases the overall size and weight of the system. Soft-switching circuits, which were originally developed to reduce switching losses, can help reduce dv/dt, but using soft-switching to accurately control dv/dt has not been fully explored. In this paper, a new soft-switching circuit, entitled the auxiliary resonant soft-edge pole (ARSEP), is set forth. ARSEP improves the available softs witching circuits so that dv/dt can be accurately controlled through the circuit parameter design. An ARSEP inverter prototype was designed, simulated, and constructed to verify its performance and benefits. Compared to a conventional hardswitched inverter with a dv/dt filter, the ARSEP inverter prototype results in a significant reduction in overall power loss, inductor volume, and weight.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Suppressing Methods of Parasitic Capacitance Caused Interference in a SiC
           MOSFET Integrated Power Module
    • Authors: Zezheng Dong;Xinke Wu;Kuang Sheng;
      Pages: 745 - 752
      Abstract: By integrating gate drivers in the silicon carbide (SiC) power module, low parasitic inductances in power loop and driving loop are realized to improve switching performance. However, the voltage variation of midpoint in the halfbridge module causes interference at the input of gate drivers. The interference loop is analyzed in this paper, considering corresponding parameters, such as parasitic capacitance and switching speed. A circuit model is derived with experimental verification. Based on the circuit model and analysis, discussions of this interference are done and it shows that serious situations such as shoot-through may happen. Therefore, different suppressing methods of this parasitic capacitance caused interference are proposed in this paper and comparison between these techniques is done, showing that the shielding method can totally eliminate this interference. This paper offers help for the design and fabrication of SiC power module with integrated gate drivers.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • 99% Efficient 10 kV SiC-Based 7 kV/400 V DC Transformer for Future
           Data Centers
    • Authors: Daniel Rothmund;Thomas Guillod;Dominik Bortis;Johann W. Kolar;
      Pages: 753 - 767
      Abstract: The power supply chain of data centers from the medium voltage (MV) utility grid down to the chip-level voltage consists of many series connected power conversion stages and accordingly shows a relatively low efficiency. Solid-state transformers (SSTs) could improve the efficiency by substantially reducing the number of power conversion stages and/or directly interfacing the MV ac grid to a 400 V dc bus, from where server racks with a power consumption of several tens of kilowatts could be supplied by individual SSTs. The recent development of SiC MOSFETs with a blocking voltage of 10 kV enables the realization of a simple and, hence, highly reliable two-stage SST topology, consisting of an ac/dc power factor correction rectifier and a subsequent isolated dc/dc converter. In this context, an isolated 25 kW, 48 kHz, 7 kV to 400 V series resonant dc/dc converter based on 10 kV SiC MOSFETs is realized and tested in this paper. To achieve zero voltage switching of all MOSFETs, a special modulation scheme to actively control the amount of the switched magnetizing current on the MV- and low voltage-sides is implemented. Furthermore, the design of all main components and, especially, the electrical insulation of the employed medium-frequency transformer are discussed in detail. Calorimetric efficiency measurements show that a full-load efficiency of 99.0% is achieved, while the power density reaches 3.8 kW/L (63 W/in3).
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Modular SiC High-Frequency Solid-State Transformer for Medium-Voltage
           Applications: Design, Implementation, and Testing
    • Authors: Dong Dong;Mohammed Agamy;Jovan Z. Bebic;Qin Chen;Gary Mandrusiak;
      Pages: 768 - 778
      Abstract: The advancements in wide-bandgap devices are enabling applications of power electronic converters coupled directly with medium-voltage (MV) grids that incorporate galvanic isolation within the converter using high-frequency solid-state transformers (SSTs). This paper presents analysis, design, and the characterization results of a 50-kVA modular soft-switched ac-ac SST using silicon carbide (SiC) MOSFET for MV (>6 kV ac) applications. The SST is comprised of two hard-switched ac-line interface bridges and a resonant dc-dc stage switched at approximately 180 kHz. To minimize the cost of switching elements per ampere and maximize the design flexibility, the design uses multiple discrete SiC devices of, readily available, 1700-V ratings. This paper covers the analysis of soft-switching operation, control architecture, converter design, and system-level integration.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • 99.1% Efficient 10 kV SiC-Based Medium-Voltage ZVS Bidirectional
           Single-Phase PFC AC/DC Stage
    • Authors: Daniel Rothmund;Thomas Guillod;Dominik Bortis;Johann W. Kolar;
      Pages: 779 - 797
      Abstract: Due to their extremely high energy demand, data centers are directly supplied from a medium-voltage (MV) grid. However, a significant part of this energy is dissipated in the power supply chain since the MV is reduced step-by-step through multiple power conversion stages down to the chip-voltage level. In order to increase the efficiency of the power supply chain, the number of conversion stages must be substantially reduced. In this context, solid-state transformers (SSTs) are considered as a possible solution, as they could directly interface the MV AC grid to a 400 V DC bus, whereby server racks with a power consumption of several tens of kilowatts could be directly supplied from an individual SST. With a focus on the lowest system complexity, the SST, ideally, should be built as simple two-stage system consisting of an MV AC/DC power factor correction (PFC) rectifier stage followed by an isolated DC/DC converter. Accordingly, this paper focuses on the design and realization of a 25 kW, 3.8 kV single-phase AC to 7 kV DC PFC rectifier unit based on the 10 kV SiC MOSFETs. By simply adding an LC circuit between the switch nodes of the well-known full-bridge-based pulse width modulated AC/DC rectifier, the integrated triangular current-mode concept is implemented, which only internally superimposes a large triangular current ripple on the AC mains current and, therefore, enables zero-voltage switching over the entire AC mains period. Special attention is paid to the realization of the MV inductors and their electrical insulation, the AC-input LCL filter to limit electromagnetic interference emissions, and the challenges arising due to cable resonances when connecting the SST to the MV grid via an MV cable. Despite the large insulation distances required for MV, the realized 25 kW MV PFC rectifier achieves an unprecedented power density of 3.28 kW/L (54 W/in3) and a full-load efficiency of 99.1%, determined using a calorimetric measurement setup, which is discussed i- detail in the Appendix.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Modular SiC-Based Step-Up Converter With Soft-Switching-Assisted
           Networks and Internally Coupled High-Voltage-Gain Modules for Wind Energy
           System With a Medium-Voltage DC-Grid
    • Authors: Mehdi Abbasi;John Lam;
      Pages: 798 - 810
      Abstract: In this paper, a fully soft-switched silicon carbide (SiC)-based modular step-up resonant converter with magnetically integrated zero current switching voltage doublers is proposed for medium-voltage (MV) dc conversion in wind energy systems. Conventional step-up resonant dc/dc converters employ either high turns-ratio step-up transformer or step-up resonant circuits to achieve step-up voltage conversion. As a result, they require either complicated expensive transformer structure due to high-voltage electrical isolation requirement or highly voltagegain sensitive step-up resonant circuits, which are not ideal for designing MV converters for wind energy application. In order to solve the aforementioned drawbacks, the proposed converter configuration utilizes both modular step-up resonant circuits and magnetically integrated voltage doublers to achieve the stepup voltage conversion function. The output voltage of each module of the dc/dc step-up converter is regulated through variable frequency control, whereas asymmetrical pulsewidth modulation (APWM) control is utilized to balance all the resonant currents in all the resonant circuit modules in each converter module. Since APWM control is used, a simple passive auxiliary circuit is included in each converter module to extend softswitching operation over a wide range of operating conditions. Simulation results on a 1-kV/28-kV, 5-MW converter system with commercial 1.2-kV SiC MOSFET modules and experimental results on a laboratory-scale 300-V/4.8-kV, 5.6-kW proof-ofconcept prototype with commercial SiC MOSFET and SiC Schottky diodes are provided to validate the theoretical analysis and to highlight the merits of the proposed work.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Highly Efficient, Full ZVS, Hybrid, Multilevel DC/DC Topology for
           
    • Authors: Branislav Stevanović;Diego Serrano;Miroslav Vasić;Pedro Alou;Jesús Angel Oliver;José Antonio Cobos;
      Pages: 811 - 832
      Abstract: Highly efficient, hybrid DC/DC topology, consisted of a standard interleaved boost followed by a multilevel resonant switched capacitor converter, which employs 900-V silicon carbide devices, for use in emerging, two-stage, grid-connected 1500-V photovoltaic systems is presented in this paper. The operation principle of this topology, controllability of the output voltage, and power distribution among the stages in function of the input voltage is described. Partial processing of the input energy and full zero-voltage switching (ZVS) transitions in all the switches, over the wide range of input voltages and output power, make this topology more efficient in comparison with the solutions presented in the literature. A simplified model of Coss for the prediction of ZVS conditions in high-voltage applications is presented. This model appears sufficiently accurate, yet it is also simple enough to be included in the optimization program without increasing the time consumption of calculations. Results of multivariable optimization (Pareto front) for the presented topology are provided. Previously described theoretical analysis is fully experimentally confirmed by building and measuring a 10-kW prototype of 8.26-kW/kg specific power and 404.6-cm3 volume occupied only by the power stage components. Euro efficiency of 99.48% in nominal input/output voltage conditions is achieved.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • $LLC$+ +Resonant+Converter+and+Phase+Shift+Full-Bridge+Converter+for+a+Dual-Output+DC–DC+Converter&rft.title=IEEE+Journal+of+Emerging+and+Selected+Topics+in+Power+Electronics&rft.issn=2168-6777&rft.date=2019&rft.volume=7&rft.spage=833&rft.epage=842&rft.aulast=Wang;&rft.aufirst=Guangdi&rft.au=Guangdi+Li;Jin+Xia;Kun+Wang;Yan+Deng;Xiangning+He;Yousheng+Wang;">Hybrid Modulation of Parallel-Series $LLC$ Resonant Converter and Phase
           Shift Full-Bridge Converter for a Dual-Output DC–DC Converter
    • Authors: Guangdi Li;Jin Xia;Kun Wang;Yan Deng;Xiangning He;Yousheng Wang;
      Pages: 833 - 842
      Abstract: A novel pulse frequency and phase shift hybrid modulated dual-output dc-dc converter is proposed in this paper. The proposed converter is composed of hybrid modulation of an input-parallel-output-series LLC resonant converter and a phase shift full bridge (PSFB) converter. The output voltage of the LLC resonant converter is modulated by the switching frequency, whereas the output voltage of the PSFB converter is modulated by the phase angle; therefore, the two output voltages are regulated independently and free from cross regulation. The series inductor of the PSFB converter does not need to be specially designed to help achieving the soft switching operation, and the duty cycle loss could be mitigated. Zero-voltage switching can be achieved on the power switches in the whole load range. Finally, a 1.2-kW 400-input 200-400-V and 48-V output prototype is built and tested to verify the effectiveness of the proposed converter.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Efficient LLC Resonant Converter With a Simple Hold-Up Time Compensation
           in Voltage Doubler Rectifier
    • Authors: Jong-Woo Kim;Moonhyun Lee;Jih-Sheng Lai;
      Pages: 843 - 850
      Abstract: LLC resonant converter is one of the promising converter topologies due to its simple structure and high efficiency. However, when LLC resonant converter is designed considering a hold-up time requirement, it has definite drawbacks such as large conduction and turn-off losses due to large circulating current. To solve this problem, various resonant converters with boost capability have been investigated. Although these methods improved overall performance, they still suffer from a large number of switching components. In this paper, anew LLC resonant converter with boost capability is introduced and verified. The advantage of the proposed converter is a small number of components while achieving the hold-up time capability. Furthermore, it achieves zero average transformer current despite its asymmetric operation. A prototype has been built and tested with 400-250-V input and 200-V/200-W output specification.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Soft-Switching Bidirectional DC/DC Converter With an LCLC
           Resonant Circuit
    • Authors: Yijie Wang;Hongyu Song;Dianguo Xu;
      Pages: 851 - 864
      Abstract: In this paper, a soft-switching bidirectional dc/dc converter with an LCLC resonant circuit is proposed. The proposed converter has the dual advantages of isolated converter and nonisolated converter. In boost mode, high efficiency can be achieved at high boost ratios. In buck mode, the circuit can also achieve automatic voltage equalization of half-bridge capacitors. In this paper, a detailed theoretical analysis of the LCLC structure is performed, and the specific operating modes of the circuit in buck and boost mode are given. The circuit modes of the soft-switching resonant process are quantitatively analyzed. The GSSA method was used to model and control the system. According to the obtained transfer function, the PID control circuit of the system is designed by using the zero-pole cancelation method, which enabled the system to obtain superior control performance. A prototype of 1000 W was made, and the experimental results are in a good agreement with the theoretical results.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Output Capacitance Loss Characterization of Silicon Carbide Schottky
           Diodes
    • Authors: Zikang Tong;Grayson Zulauf;Jiale Xu;James D. Plummer;Juan Rivas-Davila;
      Pages: 865 - 878
      Abstract: In high-frequency (HF) and very-high-frequency (VHF) rectifiers, silicon carbide (SiC) Schottky diodes exhibit higher losses compared to what is reported in manufacturer-provided simulation models, with additional power loss stemming from energy dissipation during the charging and discharging of the junction output capacitance (CJ). Because these losses are not included in manufacturer simulation models and have not been well-studied for commercially available SiC Schottky diodes, we have experimentally measured them using the Sawyer-Tower circuit. From these measurements, we compare the losses across manufacturers, current rating, generation, voltage rating, and packaging. We then demonstrate the performance of these devices on a 20-MHz class-DE rectifier and compare their power dissipation from the simulation and experimental measurements. Finally, by incorporating these losses in device power dissipation calculations in various rectifier topologies, we propose suggestions on device selection to optimize converter efficiencies.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Multisampled Digital Average Current Controls of the Versatile
           Buck–Boost Converter
    • Authors: Carlos Restrepo;Tine Konjedic;Freddy Flores-Bahamonde;Enric Vidal-Idiarte;Javier Calvente;Roberto Giral;
      Pages: 879 - 890
      Abstract: The coupled-inductor buck-boost converter is a versatile dc-dc converter, which is suitable for performing different roles within the hybrid power systems. Its multiple advantageous features include noninverting voltage step-up/step-down characteristic, high efficiency, wide bandwidth control, ability to control the input and output voltages and currents, and so on. All the existing current control approaches for this type of converter are based on analog control implementation, which allows achieving high closed-loop bandwidth. However, analog control limits the possibilities for applying the advanced control schemes and algorithms for achieving smooth operating mode transitions. This paper proposes two digital current control strategies for a versatile buck-boost converter: a predictive average current control and a multisampled average current control. Both the proposed digital control strategies ensure fast tracking of the control set point, low steady-state error, and a practically undegraded dynamic response of the system in comparison with the analog average current control. The theoretical analyses have been validated by means of simulations and experimental tests performed on a 48-V 600-W purpose-built prototype.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Current-Sensorless Power Factor Correction With Predictive Controllers
    • Authors: Felipe López;Víctor M. López-Martín;Francisco J. Azcondo;Luca Corradini;Alberto Pigazo;
      Pages: 891 - 900
      Abstract: Power factor correction (PFC) converters are widely employed for ac/dc conversion to fulfill the applicable standards while ensuring high efficiency. Current-sensorless controllers in PFCs simplify the interaction between power and control circuits, improving noise immunity. This paper reviews the state-of-the-art in-line current control techniques, identifying relevant contributions that incorporate predictive algorithms and eliminate the current sensor. Furthermore, it evaluates two approaches for current-sensorless PFC. The first is applicable to converters with diode bridge and includes a high-resolution digital control loop to cancel the estimation errors. The second, valid for bridgeless PFCs, is a new current-sensorless control, which includes a fast compensation of the prediction errors with a third-harmonic-dependent function generated from a phase locked loop. This compensation modifies the duty cycle sequence obtained from the controller, ensuring the matching of the line current with the reference obtained from the line voltage. The two evaluated approaches are investigated via computer simulations and experimentally.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • EKF-Based Predictive Stabilization of Shipboard DC Microgrids With
           Uncertain Time-Varying Load
    • Authors: Shirin Yousefizadeh;Jan Dimon Bendtsen;Navid Vafamand;Mohammad Hassan Khooban;Tomislav Dragičević;Frede Blaabjerg;
      Pages: 901 - 909
      Abstract: The performance of dc shipboard power systems (SPSs) may degrade due to the negative impedance of constant power loads (CPLs) connected to dc microgrids (MGs). To control the dcSPS effectively, estimation of the instantaneous power flow to the time-varying uncertain CPLs is necessary. Furthermore, fast adaptive control is needed to deal with changes in the CPL power flow and quick stabilization of the dc MGs. Such a controller typically uses injection current from an energy storage system for actuation. Since measuring the CPLs' powers require installing current sensors that are both costly and not optimal, an estimation of the CPLs' powers should be employed. In this paper, an extended Kalman filter (EKF) is developed to estimate a time-varying power of uncertain CPLs in a dc MG based on measuring capacitor voltages. The estimated power is then used in a Takagi-Sugeno fuzzy-based model predictive controller (MPC) to manipulate the energy storage unit. The proposed approach is tested experimentally on a dc MG that feeds a single CPL. The experimental results show that the proposed MPC controller alongside the developed EKF improves the transient performance and the stability margin of the dc MGs used in the SPSs.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Family of Switched-Resonant Converters With Wide Conversion Ratio and
           Controlled Sourcing Features for Volume-Sensitive Applications
    • Authors: Alon Cervera;Mor Mordechai Peretz;
      Pages: 910 - 921
      Abstract: In this paper, a family of switched-resonant converters with high efficiency over a wide conversion ratio range is introduced. Inspired by the gyrator resonant switched-capacitor concept, the new topology provides high efficiency over wide and continuous range of conversion ratios using a single resonator. This is enabled by new modes of operation (switching sequences) developed and analyzed in this paper that modify the charge balance of the flying capacitor. By that, the sourcing as well as the efficiency characteristics of the converter can be shaped to peak at various conversion ratios. A generalized methodology is presented to describe resonant converters with multiple operation modes as a two port which is then used to analyze several operational modes of the presented topology. Experimental results validate the developed theoretical model and demonstrate the superiority of the concept in terms of efficiency (over 10%) and current-sourcing capabilities (over 80%) using a compact 5-W prototype.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Model Predictive Control for a Hybrid Multilevel Converter With Different
           Voltage Ratios
    • Authors: Shuai Xu;Jianzhong Zhang;Xing Hu;
      Pages: 922 - 935
      Abstract: This paper proposes a model predictive control (MPC) strategy for a new hybrid multilevel converter (HMC) with different capacitor voltage ratios. The HMC provides redundant switching states, making it easy to balance the flying capacitor (FC) voltages. A discrete-time model of the HMC is built, where all the control objectives are formulated with the switching functions. The optimum switching state will be selected by evaluating all redundant switching states to minimize the cost functions. Compared with multicarrier pulsewidth modulation methods, the MPC does not require complex modulations, and the proposed HMCs can be operated with different voltage ratios to generate higher voltage levels without increasing the number of switches and FCs by using the MPC. Experimental results validate the effectiveness of the proposed control strategy for the HMCs under various operating conditions. The sensitivity of parameters is also studied with large load variations.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Hardware-in-the-Loop Realization of a Robust Discrete-Time Current
           Control of PMa-SynRM for Aerospace Vehicle Applications
    • Authors: Mahmoud Amin;Ghada A. Abdel Aziz;
      Pages: 936 - 945
      Abstract: The hardware-in-the-loop (HIL) realization platform significantly supports the advance of control techniques in secure, precise, and low-cost design. Innovative control techniques are anticipated to ensure aerospace vehicle drive controllability. This paper presents a novel robust discrete-time (RDT) predictive current control (PCC) strategy of a permanent-magnet-assisted synchronous reluctance motor (PMa-SynRM) implemented using the HIL tool and the experimental setup. The proposed RDT controller has a discrete-time integral term added to the conventional deadbeat (DB) current predictive control to improve the robustness and stability of the current control. The PMa-SynRM mathematical model with parameter uncertainties is theoretically derived. Conventional PCC techniques are constructed utilizing the DB framework. Although this controller has a good dynamic response, it still suffers from unmodeled transient changes as well as parametric motor uncertainties. A 6-kW PMa-SynRM machine drive system is built and tested using DS1104 R&D Controller Board. Typhoon HIL is used to emulate the PMa-SynRM and the inverter connected to a dSPACE MicroLabBox. The performance of the proposed RDT technique is assessed and compared with traditional DB using the HIL and experimental results under different speed commands, electrical and mechanical motor parameters variations, and rated speed reversal conditions.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Predictive Common-Mode Voltage Suppression Method Based on Current Ripple
           for Permanent Magnet Synchronous Motors
    • Authors: Xiaofan Wang;Xiaochun Fang;Shuai Lin;Fei Lin;Zhongping Yang;
      Pages: 946 - 955
      Abstract: Compared with the pulsewidth modulation-based field-oriented control scheme, finite control set model predictive control (FCS-MPC), which has been widely concerned, has great advantages in fast dynamic response, multiobjective control, and system constraint processing. The common-mode voltage (CMV) generated by the inverter will lead to bearing damage and electromagnetic interference issues. This paper studies CMV suppression method based on FCS-MPC for permanent magnet synchronous motor fed by voltage source inverter. The use of zero voltage vector can significantly increase the output CMV of the inverter. The method of abandoning the zero vector directly can decrease CMV, but will lead to larger current distortion. Replacing the zero vector with nonadjacent vectors is a better way but will lead to higher switching frequency. When the CMV is introduced into the cost function, the tradeoff between CMV suppression and current distortion can be realized, but there is no rule to be followed for weight coefficient design. In this paper, we propose a variable FCS scheme based on current ripple. Based on this scheme, CMV can be suppressed under the premise that the current distortion is small, and the switching frequency is not significantly increased. Based on the proposed method, current distortion and CMV can be well balanced under different load conditions by setting the relative error limits. Experimental results show that the proposed method has good control performance under various operation conditions.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Model Predictive Direct Power Control With Fixed Switching Frequency and
           Computational Amount Reduction
    • Authors: Bihua Hu;Longyun Kang;Junfeng Liu;Jun Zeng;Shubiao Wang;Zhi Zhang;
      Pages: 956 - 966
      Abstract: The model predictive direct power control (MPDPC) has attracted significant attention due to its outstanding dynamic response and high power factor. However, the variable switching frequency makes the design of alternating current (ac) filter more challenging, and the heavy computational burden limits the application of MPDPC. This paper proposed a new cost function and four steps' MPDPC (FSMPDPC) scheme for T-type inverters. The proposed cost function can reduce the number of division operations and does not require calculating the duty cycles of all vectors. Meanwhile, the four steps' calculation process is divided into four steps to reduce the number of cycle calculations. The first three steps are assigned to adjust the active and reactive powers, and the neutral-point (NP) voltage is balanced in the fourth step. An experimental platform of a T-type inverter is established to demonstrate the superiorities of the proposed FSMPDPC. The results show that FSMPDPC improves the steady-state performance of the T-type inverter with lower current total harmonic distortion (THD) and lower ripples in the active and reactive powers. In addition, the proposed algorithm eases the computational burden of the digital signal processor (DSP).
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Predictive Power Control for DFIG: A FARE-Based Weighting Matrices
           Approach
    • Authors: Lucas L. Rodrigues;Omar A. C. Vilcanqui;André L. L. F. Murari;Alfeu J. Sguarezi Filho;
      Pages: 967 - 975
      Abstract: Model predictive control (MPC) is a very popular technique for doubly fed induction generator (DFIG), and several MPC topologies have been proposed. However, most of the time, the controller parameters are done in a heuristic way. This paper proposes an analytical method for the design weighting matrices based on the fake algebraic Riccati equation (FARE). The proposed methodology guarantees the control system stability. Furthermore, simulations results were used to choose the desired control horizon and the desired prediction horizon, considering the steady-state error and the computational cost. Moreover, the DFIG vector control model, the MPC theory, and the FARE formulation were presented. Experimental results were shown to endorse the proposed method.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Modular Multilevel Converter With Improved Indirect Predictive Controller
    • Authors: Minglin Zhu;Guojie Li;
      Pages: 976 - 989
      Abstract: The modular multilevel converter (MMC) now is considered as the most promising converter in the high-voltage direct current system. An improved indirect predictive control applied in the MMC is proposed in this paper. With the proposed predictive control, the burden of communication can be reduced. The predictive precision can be improved with the proposed controller. Furthermore, the control accuracy for the system can be improved. In this paper, the mathematical model of the MMC is presented at first. Based on the model, the stability analysis of current control loop is obtained and the gain boundaries of the controllers are deduced. Afterward, the indirect predictive control is applied in the control loop. The predictive errors caused by the circuit parameters uncertainties are further deduced. Moreover, in order to eliminate the predictive error and improve the predictive precision, the repetitive controller is introduced in the submodule voltage balance controller. At last, the validity and advantages of the proposed method are verified by a bunch of simulating and experimental results.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Novel Current Predictive Control Based on Fuzzy Algorithm for PMSM
    • Authors: Zhiqiang Wang;Anbo Yu;Xinmin Li;Guozheng Zhang;Changliang Xia;
      Pages: 990 - 1001
      Abstract: The fast and stable current inner loop in the permanent-magnet synchronous motor (PMSM) control system is the key factor that ensures the torque control performance of the motor. The deadbeat model predictive control strategy can achieve fast dynamic response, but it depended on the accurate mathematical model of the motor. When the model parameter in the predictive controller has mismatched with real system, the static error or oscillations will occur in the steady state. Therefore, a novel current predictive control based on the fuzzy algorithm is proposed in this paper. The novel control strategy contained a predictive controller, a proportional-integral (PI) compensation link, a magnetic flux observer, and a fuzzy controller. According to the operation state of the motor and the model parameter mismatch of the controller, the fuzzy algorithm can adjust the effect of compensation link by weight coefficient in real time. The dynamic performance of the proposed method is guaranteed compared with the traditional deadbeat predictive current control based on the space vector pulsewidth modulation (SVPWM). When the model parameter mismatch of controller is occurred, the weight of the PI compensation link is enhanced, and the static error or oscillation of the motor system can be eliminated.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Hybrid Model Predictive Multilayer Control Strategy for Modular
           Multilevel Converters
    • Authors: Su Zhang;Udaya Kumara Madawala;
      Pages: 1002 - 1014
      Abstract: This paper presents a novel hybrid model predictive multilayer control (HMPMC) strategy for modular multilevel converters (M2LCs). The proposed hybrid strategy uses a modified model predictive direct slope control (MPDSC) concept to regulate the load current while concurrently minimizing the switching frequency, circulating current, and capacitor voltage variations through a new MPMC concept. The multilayer philosophy uses dedicated control layers to independently evaluate its control variables. As the main advantage, the hybrid strategy enables operation of M2LC at low switching frequencies. Moreover, this paper proposes a hierarchical screening algorithm, which estimates the minimum number of switching states required to be evaluated for each control variable, reducing the computational burden. An execution order for each control layer, in which the variables are assigned to control layers as appropriate, is also incorporated to further reduce the computational burden. Instead of using conventional weighting factors, this paper uses tuning factors for each layer, which is based on the number of switching states of the lowest cost to make the tuning process efficient and adaptable to any operating conditions. To demonstrate the validity, a prototype singlephase, five-level, 380-VA M2LC is designed, built, and controlled through the proposed strategies. The performance of prototype is investigated under both the steady-state and transient conditions, and the experimental results are presented in comparison with simulations and benchmarked against both the conventional finite control set model predictive control (FCS-MPC) and an improved MPC strategy. The results clearly indicate that the proposed strategy enables efficient operation of the converter at both significantly lower switching frequency and reduced computational burden, which is preferred for high-power applications.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Optimal Shaping of the MMC Circulating Currents for Preventing AC-Side
           Power Oscillations From Propagating Into HVdc Grids
    • Authors: Gilbert Bergna-Diaz;Jon Are Suul;Erik Berne;Jean-Claude Vannier;Marta Molinas;
      Pages: 1015 - 1030
      Abstract: A constrained optimization problem based on the Lagrange multipliers method is formulated to derive the circulating current references of modular multilevel converters (MMCs) directly in abc coordinates. The resulting analytic expressions for calculating the circulating current reference signals are designed to eliminate oscillations in the dc-side power flow, independently of the ac-side operation of the MMC. As a result of the constrained optimization, the circulating currents are shaped to optimally utilize the degrees of freedom provided by the internal energy buffering capacity of the MMC, to effectively decouple the ac-grid conditions from the dc bus. This property of the proposed control method makes it especially suitable for preventing oscillations due to unbalanced ac-grid voltage conditions from propagating into multiterminal high-voltage dc systems. It is shown that the power flow at the dc-side of the MMC will be most effectively decoupled from ac-side transients if the desired steady-state power flow is imposed by acting directly on the circulating current references instead of by acting on the ac-side current references. The operation of an MMC controlled by the proposed approach is demonstrated by simulation studies, verifying the ability to keep the dc power flow free of second harmonic oscillations, independently of the power control objectives applied for calculating the ac-side current references of the converter.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Near Optimal Controller Tuning in a Current-Mode DPWM Boost Converter in
           CCM and Application to a Dimmable LED Array Driving
    • Authors: K. Hariharan;Santanu Kapat;
      Pages: 1031 - 1043
      Abstract: A boost converter exhibits a nonminimum phase behavior while operating in continuous conduction mode. This is due to the existence of a right-half-plane zero that significantly restricts the closed-loop bandwidth. Using the phase- plane geometry, this paper proposes a nonlinear tuning approach in a digitally current-mode controlled boost converter with a proportional-integral voltage controller. Considering a load current feed-forward with a normalized gain kn, optimal proportional gains are analytically derived in order to achieve near time optimal recovery under both load and reference step transients. The optimal gain is shown to be equally applicable for a (nonminimum phase) noninverting buck-boost converter by suitably updating kn. Large-signal stability analysis is carried out, and the effects due to finite sampling and parameter variations are discussed. The proposed tuning significantly improves the transient response over existing small-signal-based tuning methods. The constraints on the current overshoot and/or voltage deviation are also considered, and their effects on the transient performance are studied. A boost converter prototype is tested using resistive and dimmable (white) LED array loads. The proposed tuning is realized using a field-programmable gate array device; improved performance and efficiency are demonstrated using test results.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • $pi$+ -Type+Converter&rft.title=IEEE+Journal+of+Emerging+and+Selected+Topics+in+Power+Electronics&rft.issn=2168-6777&rft.date=2019&rft.volume=7&rft.spage=1044&rft.epage=1059&rft.aulast=Yuan;&rft.aufirst=Bosen&rft.au=Bosen+Jin;Xibo+Yuan;">Topology, Efficiency Analysis, and Control of a Four-Level $pi$ -Type
           Converter
    • Authors: Bosen Jin;Xibo Yuan;
      Pages: 1044 - 1059
      Abstract: This paper provides a comprehensive analysis for a four-level π-type converter for low-voltage applications. This topology is a kind of reduced device-count neutral-point-clamped multilevel converter and formed by only six switches in each phase leg. The line (phase-to-phase) output voltage can have seven levels and the output harmonics are much lower than that of a standard two-level converter. The switching states and their associated output voltage levels have been analyzed. A generalized averaged analytical power loss model of this converter has also been developed to investigate the loss distribution among the power devices as well as the efficiency. The four-level π-type converter has a higher efficiency when the switching frequency is above 5 kHz compared with two-level and three-level converters with the power devices used in this paper. The reduced output harmonics, hence reduced filtering requirement together with improved efficiency and cooling (heat sink) requirement, offer a higher density alternative to the two-level converter. A simplified level shifted carrier-based modulation method with dynamic optimal zero-sequence signal injection has been employed to modulate the converter and to control dc-link neutral-point voltages. This paper has experimentally validated the predicted four-level π-type converter efficiency and the neutral-point voltage balancing control with a back-to-back configuration under high modulation indices and unity power factor. The neutralpoint voltage balance region has been plotted and experimentally verified.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Hard-Switching 650-V GaN HEMTs in an 800-V DC-Grid System With
           No-Diode-Clamping Active-Balancing Three-Level Topology
    • Authors: Wei Qian;Juncheng Lu;Hua Bai;Scott Averitt;
      Pages: 1060 - 1070
      Abstract: For any voltage above 600-V dc, it is usually recommended to use 900-1200-V SiC MOSFETs instead of GaN high-electron-mobility transistors (HEMTs), given presently commercial GaN HEMTs have the maximum voltage rating up to 650 V. This paper is an attempt of employing 650-V E-mode GaN HEMTs to build a three-level bidirectional dc/dc converter, with the input as an 800-V battery, the output as the ~400-V dc grid, and half of the switches working at the hard-switching mode. The active-balancing control instead of using clamping diodes in the conventional neutral-point clamping topology is adopted, aiming at higher efficiency. Simulation based on the double-pulse test results shows that such a design strategy with GaN has a better efficiency over the conventional 1200-V SiC MOSFETbased buck/boost converter. Two bottom-cooled GaN HEMTs are in parallel to enhance the power capability and efficiency, which require the special focus on the parasitic parameters. The effects of parasitics, especially the stray inductance in the current commutating loop and the gate drive loop during switching transitions, have been comprehensively analyzed in this paper. Experimental results under 800-V bus voltage are presented to verify the proposed solution.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Practical Analytical Model and Comprehensive Comparison of Power Loss
           Performance for Various MMCs Based on IGCT in HVDC Application
    • Authors: Biao Zhao;Rong Zeng;Jianguo Li;Tianyu Wei;Zhengyu Chen;Qiang Song;Zhanqing Yu;
      Pages: 1071 - 1083
      Abstract: This paper gives a comprehensive analysis and characterization of power loss of a high-power integrated gate-commutated thyristor (IGCT) in a modular multilevel converter (MMC) for a high voltage dc application. The practical scheme, power loss models, calculation methods, characterization of MMC based on IGCT are analyzed in detail. Especially, a comprehensive comparison of both half-bridge MMC (HB-MMC) and full-bridge MMC (FB-MMC) based on IGCT, press-pack insulated gate bipolar transistor (IGBT), module-type IGBT, press-pack injection enhanced gate transistor (IEGT), and module-type IEGT is analyzed in this paper. According to the study in this paper, the snubber power loss of MMC based on IGCT is far less than the conduction and switching power losses. Both the conduction and switching power losses of IGCT are always lower than that of press-pack and module-type IGBTs and IEGTs in MMC. The power loss of FB-MMC is higher than that of HB-MMC with the same transmission power because more switches are employed in FB-MMC. If taking diodes into account, the HB-MMC and FB-MMC based on IGCT can decrease power loss about 1.9%-49.3% and 8.3%-45.1% under different operation states, respectively. The study in this paper will provide a valuable reference and promote the application of IGCT in MMC.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • An F-Type Compensated Capacitive Power Transfer System Allowing for Sudden
           Change of Pickup
    • Authors: Yu-Gang Su;Yu-Ming Zhao;Aiguo Patrick Hu;Zhi-Hui Wang;Chun-Sen Tang;Yue Sun;
      Pages: 1084 - 1093
      Abstract: When wirelessly supplying electric power to movable devices using capacitive power transfer (CPT) technology, the sudden move in and move out of the pickup will cause a sudden change to the system structure. As a result, the current and voltage of the inverter may increase dramatically, which may destroy the semiconductor switches or other circuit components, and the system may consume a lot of power after the pickup is removed. To address the issues, this paper proposes an F-type compensated CPT system based on the characteristics of the inductor-capacitor-inductor resonant network. A steady-state model of the proposed CPT system is established, and a set of design equations is provided. The feasibility and validity of the proposed topology and its parameter design method have been verified by the simulation and experimental results. It has demonstrated experimentally that the CPT prototype can be self-protected and automatically enter standby mode after the pickup is removed, and restore to deliver the required power (>25 W) to the load at a high power efficiency (>80%) after the pickup is moved back to the primary circuit, which are the inherent features of the proposed system rather than relying on any additional detection and control.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A New Generalized Multilevel Converter Topology With Reduced Voltage on
           Switches, Power losses, and Components
    • Authors: Jagabar Sathik Mohamed Ali;Rasoul Shalchi Alishah;Vijayakumar Krishnasamy;
      Pages: 1094 - 1106
      Abstract: In this paper, a new submultilevel converter (SMC) is introduced first. Then, the cascaded structure based on the series connection of proposed SMCs is presented. The proposed cascade topology can generate all possible levels at output voltage waveform. In order to show the advantages of the presented topology, the comparison results with recently proposed multilevel converters are provided. According to the comparison results, it is indicated that the proposed structure requires the least number of power switches and dc sources. Also, the total blocked voltage by the switches and power losses of the proposed cascade topology is less than other topologies. The presented topology can be used in high-voltage applications. In order to verify the performance of the presented topology, the experimental and simulation works are provided.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Analysis of DC Fault for Dual-Active Bridge DC/DC Converter Including
           Prototype Verification
    • Authors: M. I. Rahman;K. H. Ahmed;D. Jovcic;
      Pages: 1107 - 1115
      Abstract: This paper presents dc fault analysis for a dualactive bridge (DAB) dc/dc converter which comprises two active bridges and an internal medium frequency transformer. This topology provides galvanic isolation, voltage step up/down and bidirectional power transfer. The dc fault study assumes the dc terminal voltage of the converter is at zero. The steady-state fault current is limited to a low magnitude which is less than the rated value without any controller action depending on the design of the converter. The dc fault current magnitudes are analyzed with ac equivalent circuit where only the fundamental component of the ac voltages and inductor current are considered. Phase shift and ac voltage magnitude modulation control methods are selected. A detailed DAB dc/dc converter 3-MW, 4-/40-kV-based system is simulated using MATLAB/Simulink to validate the proposed analytical study. Further, hardware testing is conducted to confirm the dc fault studies with a 500-W 24-/100-V prototype.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Evaluation and Improvement of Active Stabilization Method for Matrix
           Converter Under Input Voltage Disturbances
    • Authors: Jiaxing Lei;Shuang Feng;Bo Zhou;Wu Cao;Jianfeng Zhao;
      Pages: 1116 - 1125
      Abstract: For matrix converter (MC), real-time correction of duty cycles is a good solution to eliminate the effects of input voltage disturbances on output performance. However, MC adopting this solution suffers from stability deterioration. The typical active stabilization method is based on modifying output voltage reference with the filtered input voltage. In this paper, its performance is evaluated under input voltage disturbances. It is found that this method will introduce extra low-frequency harmonics into output reference voltage, degrading the output quality. The reason lies in the inability of the adopted digital high-pass filter to block the disturbances. To maintain a good output performance, the improved active stabilization method is proposed, which utilizes resonant controllers to eliminate the extra low-frequency harmonics. The principle and the implementation of the improved method are presented. The consideration of input frequency variation and the influence on input power quality are also discussed. Experimental results have verified the correctness of the performance evaluation and effectiveness of the proposed improvement.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Open-Loop Gate Control for Optimizing the Turn-ON Transition of SiC
           MOSFETs
    • Authors: Yang Han;Haifeng Lu;Yongdong Li;Jianyun Chai;
      Pages: 1126 - 1136
      Abstract: This paper presents a novel open-loop gate control of the turn-ON transient for SiC MOSFETs in hard switching conditions. The gate control could reduce the SiC MOSFETs turn-ON gate voltage overshoot and control turn-ON di/dt and dv/dt independently. Because of the high turn-ON speed, SiC MOSFETs bring serious electromagnetic interference (EMI) in the half-bridge topology. A conventional gate driver decreases EMI by increasing the gate resistor, but clearly increasing the turn-ON loss. To address this tradeoff and optimize SiC MOSFETs turn-ON transition, the drain current slope and the drain-source voltage slope are controlled independently by controlling the gate-source voltage profile during the current rise phase and the gate current during the voltage falling phase. In addition, gate voltage overshoot is considered and discussed. By adding a considerably higher gate resistance during the ON-state operation stage, gate voltage overshoot is almost nonexistent while maintaining low turn-ON loss. The experimental verifications of the proposed approach are finally conducted, and the advantages of proposed driver are analyzed and discussed.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Generalized Power Decoupling Control for Single-Phase Differential
           Inverters With Nonlinear Loads
    • Authors: Wenli Yao;Yan Xu;Yi Tang;Poh Chiang Loh;Xiaobin Zhang;Frede Blaabjerg;
      Pages: 1137 - 1151
      Abstract: Differential inverters provide a cost-effective solution to the second-order ripple power issue in single-phase systems. Most existing differential inverter-based power decoupling methods are for linear loads, which may not work well for nonlinear loads. When supplying nonlinear loads, differential inverters may suffer from harmonics at the ac terminal, which may propagate to the dc side and deteriorate the performance of power decoupling. In this paper, the harmonic mitigation is realized by reshaping capacitor voltages, and it is applied to buck-, boost-, and buck-boost-type differential inverters with detailed harmonics compensation capacity analysis. Then, a feedback linearization-based dc current feedback control scheme is proposed to realize the harmonic mitigation; hence, both the dc-side ripple power and the nonlinearity found in differential inverters can be decoupled simultaneously. The proposed control scheme is developed based on a generalized half-bridge model and can be applied to buck-, boost-, or buck-boost-type differential inverters with minor revisions. Experimental results are presented to validate the performance of the proposed control scheme and theoretical analysis.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Modulation Schemes for Medium-Voltage PWM Current Source Converter-Based
           Drives: An Overview
    • Authors: Qiang Wei;Ling Xing;Dewei Xu;Bin Wu;Navid R. Zargari;
      Pages: 1152 - 1161
      Abstract: Pulsewidth modulation current source converter (CSC)-based drive is one of the widely used drives in high-power (megawatt level) medium-voltage (MV) (2.3-6.6 kV) applications. The switching frequency of the MV CSC is limited to around 500 Hz to satisfy thermal requirement and reduce switching loss. Under such a condition, the overall performance of the used modulation scheme, especially its harmonics performance, is an important consideration for CSC-based drives. To date, a couple of modulation schemes have been proposed for MV CSCs, and this paper aims to present an overview of these modulation schemes. Traditional modulation schemes are reviewed, the recent advances are illustrated and analyzed, and the challenges and trends are discussed.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Simplified Predictive Torque Control Scheme for Open-End Winding
           Induction Motor Drive
    • Authors: Kodumur Meesala Ravi Eswar;Kunisetti Venkata Praveen Kumar;Thippiripati Vinay Kumar;
      Pages: 1162 - 1172
      Abstract: Variable speed induction motor (IM) drives with predictive torque control (PTC) technique is an advancing technology nowadays. The PTC technique is introduced for dualinverter fed open-end winding IM (OEWIM) configuration owing to its benefits. The conventional PTC requires flux weighting factor assignment because of two different control objectives (torque and flux) in single cost function. This weighting factor selection plays a key role in selecting optimal voltage vector for better torque and flux response. Several analytical and empirical methods are introduced for optimal selection of weighting factor, which demands more computation time. This paper aims to develop modified PTC, eliminating flux weighting factor. The flux control objective is replaced by an equivalent reactive torque control. Thus making two control objectives of the same units and eliminating the requirement of flux weighting factor in cost function. Furthermore, nearest voltage vector selection strategy is introduced to limit the number of prediction voltage vectors in each sampling period. Thus, overall computational burden is reduced achieving minimum torque and flux ripples. The performance of the proposed PTC for multilevel inversion fed OEWIM is evaluated through MATLAB/Simulink simulations and experimental analysis. To highlight its benefits, these results are compared with those of the conventional and recent PTC techniques.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Single-Stage Sensorless Control of a PV-Based Bore-Well Submersible BLDC
           Motor
    • Authors: S. Sashidhar;V. Guru Prasad Reddy;B. G. Fernandes;
      Pages: 1173 - 1180
      Abstract: Permanent magnet (PM) brushless dc (BLDC) motor-based photovoltaic water pumps are becoming popular in rural areas due to their higher efficiency and reliability compared to induction motor-based pumps. The water table level in these rural areas is typically more than 15 m. Hence, deep bore-well submersible motors are used for extracting potable water from the water table. The motor and controller are submerged in the water table, and have more temperature rise due to the poor ambience. Thus, control of a PM BLDC motor with hall-effect-based position sensors is unreliable in these environments due to the temperature sensitivity of the hall-effect sensors. In this paper, a single-stage sensorless control of a deep borewell submersible ferrite PM BLDC motor drive is presented. A position sensorless control scheme is implemented to eliminate the use of hall sensors, thus improving reliability of the overall system. Furthermore, the challenges involved in the control of a deep bore-well submersible ferrite PM BLDC motor are elaborated. The prototype of a 1.5-kW submersible BLDC motor drive is fabricated and the experimental results are presented.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Multimode Operation for On-Line Uninterruptible Power Supply System
    • Authors: Jinghang Lu;Mehdi Savaghebi;Saeed Golestan;Juan C. Vasquez;Josep M. Guerrero;Albert Marzabal;
      Pages: 1181 - 1196
      Abstract: To enhance the robustness and disturbance rejection ability of an on-line uninterruptible power supply (UPS) system, an internal model control-based dc-link voltage regulation method is proposed in this paper. Furthermore, the multimode operations of the on-line UPS system are investigated and their corresponding control strategies are proposed. The proposed control strategies are capable of achieving the seamless transition in traditional normal mode, photovoltaic-aided normal mode, enhanced eco-mode (EEM), and burn-in test mode (BTM). Meanwhile, the uninterruptible load voltage is promised during the mode transition. The small-signal analysis is also conducted to investigate the stability of EEM and BTM. Finally, extensive experimental results are provided to validate the effectiveness of the proposed methods.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • A Novel Dual-Input ZVS DC/DC Converter for Low-Power Energy Harvesting
           Applications
    • Authors: Liang Yu;Haoyu Wang;
      Pages: 1197 - 1206
      Abstract: In this paper, a novel dual-input dc/dc topology is proposed for low-power energy harvesting applications. The converter is able to interface with two different power sources simultaneously. In the proposed topology, two boost converters are integrated with a shared diode and a filter capacitor, while the gate signals of two power MOSFETs are complimentary with certain dead-bands. The proposed topology may operate either in discontinuous-conduction mode or in hybrid conduction mode. In each operation mode, zero-voltage switching is achieved for both MOSFETs, while zero-current switching is achieved for the power diode, without any additional auxiliary circuit. Theoretical analysis, circuit modeling, and design considerations are also addressed in detail in this paper. Finally, a 10.1-W, 200-kHz prototype is designed and tested to validate the proof of concept. Experimental results are in accordance with the theoretical analysis.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Carrier-Based Digital PWM and Multirate Technique of a Cascaded H-Bridge
           Converter for Power Electronic Traction Transformers
    • Authors: Jingxi Yang;Jianqiang Liu;Yunming Shi;Nan Zhao;Jiepin Zhang;Li Fu;Trillion Q. Zheng;
      Pages: 1207 - 1223
      Abstract: In the existing technique for power electronic converters with low switching frequency and multiple cells, the sampling frequency is always set at the same value as the control frequency, and the modulating wave in each cell updates itself when its corresponding carrier reaches its peak and valley. In this paper, this implementation scheme is denoted by asymmetrically sampled-pulse width modulation (AS-PWM). It is proven that AS-PWM suffers from three defects: further increase of switching frequency is restricted by the available control period and the total cell number; long modulator delay exists and may bring the control system into instability if high crossover frequency is chosen; and spectrum aliasing toward the digital modulating waves may occur and makes the ac input current distorted. Therefore, another implementation scheme of carrier-based digital PWM is recommended in this paper, which is denoted by multisampled PWM (MS-PWM). In MS-PWM, all of the modulating waves update themselves at the same time. The research presented in this paper is based on a power-electronic traction transformer (PETT), which is made up of a cascaded H-bridge converter and several dc/dc converters. For the consideration of scalability, control, and reliability, a star-connected distributed control system is adopted for the PETT equipment. In order to make full use of this distributed hardware, and to improve the control performance with relatively low requirement toward the digital chips, a universal-type multirate structure is proposed in this paper, which is based on the MS-PWM technique. In the proposed structure, the sampling frequency, control frequency, and modulating-wave updating frequency can be separated from the switching frequency, and each of them can be chosen independently according to the practical control demand and the hardware condition. There is no mutual effect between their selections. The influence of the variation of these three fr-quencies on the control performance is analyzed as well. At last, experimental results based on a five-cell PETT laboratory prototype with a rated power of 30 kW are provided, and all of them verify the effectiveness and correctness of the proposed algorithms.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Fundamental Circuit Topology of Duo-Active-Neutral-Point-Clamped,
           Duo-Neutral-Point-Clamped, and Duo-Neutral-Point-Piloted Multilevel
           Converters
    • Authors: Vahid Dargahi;Mostafa Abarzadeh;Keith A. Corzine;Johan H. Enslin;Arash Khoshkbar Sadigh;Jose Rodriguez;Frede Blaabjerg;Atif Maqsood;
      Pages: 1224 - 1242
      Abstract: Multilevel voltage-source converters are well-suited for power conversion applications demanding higher power density, reliability, efficiency, and power quality. An unremitting and persistent research for developing advanced multilevel converter topologies with improved characteristics, performance, modulation techniques, and control methods continues. This paper proposes duo-neutral-point-clamped (D-NPC), duo-active-neutral-point-clamped (D-ANPC), and duo-neutral-point-piloted (D-NPP) multilevel voltage-sourced converter topologies. The D-NPC, D-ANPC, and D-NPP converters phase-leg is realized by adding low-frequency semiconductor power switches to their structures. This results in a substantial reduction in the number of the high-frequency pulse width-modulation insulated-gate bipolar transistors and clamping passive devices including diodes as well as flying-capacitors (FCs). Moreover, a drastic abatement in the total voltage rating and total stored energy of the FCs within the D-ANPC topology is achieved compared to the classic ANPC configuration. The experimental results are provided for D-NPC, D-ANPC, and D-NPP converters to validate the feasibility of their topology and modulation method for control of the multilevel converters.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • High-Voltage Gain Quasi-SEPIC DC–DC Converter
    • Authors: Yam P. Siwakoti;Ali Mostaan;Ahmed Abdelhakim;Pooya Davari;Mohsen N. Soltani;Md. Noman Habib Khan;Li Li;Frede Blaabjerg;
      Pages: 1243 - 1257
      Abstract: This paper proposes a modified coupled-inductor SEPIC dc-dc converter for high-voltage-gain (2
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Operation and Control Methods of Modular Multilevel Converters in
           Unbalanced AC Grids: A Review
    • Authors: Jinke Li;Georgios Konstantinou;Harith R. Wickramasinghe;Josep Pou;
      Pages: 1258 - 1271
      Abstract: High-voltage direct current (HVdc) transmission systems based on modular multilevel converters (MMCs) are a promising solution for efficient bulk power transmission over long distances. As in grid-connected converters, the occurrence of grid-side faults is rather common, leading to imbalances and distortions of the ac-side voltages. Therefore, operation and control of MMC-HVdc systems under grid imbalances become of great significance in order to satisfy grid codes and reliability requirements of the system. The aim of this paper is to provide a comprehensive review of operation and control methods applied to MMC-HVdc systems with a specific focus on unbalanced ac-grid conditions. The methods are classified based on their main control targets that include ac-side power control, control of the circulating current, and dc-side power ripple suppression control. Special attention is given to the comparison of the different control methods and specific requirements under certain operating conditions that include grid, load, or internal imbalances.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Isolated Series-Capacitor-Based Full-Bridge Converter With Reduced
           Circulating Losses and Wide Soft Switching Range
    • Authors: Zhangyong Chen;Yong Chen;Qiang Chen;
      Pages: 1272 - 1285
      Abstract: Aiming at the limitations of traditional full-bridge dc/dc converters, such as, narrow soft switching range, large circulating loss during the freewheeling period, and voltage oscillation on the rectifier diodes, in this paper, a series capacitor-based full-bridge dc/dc converter is presented to reduce the voltage stress of power switches to half of input voltage, and by introducing the asymmetric pulsewidth modulated (APWM) scheme to the proposed converter, zero-voltage switching for all the switches in the proposed converter can be obtained. Moreover, due to the reduced voltage turned-OFF stress for switches, the energy of commutation process for switches is reduced and turned-OFF switching losses can be decreased. Therefore, wide soft switching range for the proposed converter could be achieved on the condition of variable input voltage and load power. Furthermore, a simple auxiliary circuit on the secondary side of the transformer is utilized to clamp the voltage stress of rectifier diodes and voltage oscillation is eliminated. Moreover, during the freewheeling period, the current through the primary side of the transformer can be decay to zero; circulating losses are eliminated and zero current switching for the lagging switches could be achieved. The circuit configuration, operating principle, and relevant analysis results of the proposed converter are analyzed, and a design example is given in this paper. Finally, experimental results from a 400-W 300-380-V/42-V prototype are presented to verify the analysis of the proposed converter.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Accurate Power Sharing With Harmonic Power for Islanded Multibus
           Microgrids
    • Authors: Tuan V. Hoang;Hong-Hee Lee;
      Pages: 1286 - 1299
      Abstract: In an islanded multibus microgrid, accurate power sharing is more difficult than in a traditional single-bus microgrid due to its complex inner structure. This paper proposes an enhanced power sharing control scheme to share accurately dominant harmonic powers for the multibus microgrids with the aid of adaptive regulation of the virtual impedances at dominant frequencies. The proposed control method provides accurate harmonic power sharing even when the microgrid configuration or the load condition is changed. Moreover, a simple secondary controller has also been proposed to remove the frequency/voltage deviations without additional voltage measurement at the point of common coupling. The proposed control scheme can be implemented directly in any type of the microgrid structure (single bus or multibus) without any information about the detailed microgrid configuration, feeder impedances, and the load powers, which decreases complexity and system cost. The proposed control method is theoretically investigated, and its feasibility and effectiveness are validated via simulation and experiment.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Flexible Inertia Optimization for Single-Phase Voltage Source Inverter
           Based on Hold Filter
    • Authors: Hong Li;Xiaochao Zhang;Tiancong Shao;Trillion Q. Zheng;
      Pages: 1300 - 1310
      Abstract: With the increasing penetration of renewable energy sources (RESs) in the power system, voltage source inverters (VSIs) are widely used as the power electronic interface of the RESs, which will decline the inertia of power system. The insufficient inertia has been becoming a big challenge for the modern power system. Synchronverter (SV) technology can operate the inverter mimic the characteristic of the synchronous generator to provide virtual inertia. However, the virtual inertia of conventional SV is associated with the frequency stability, which limits the inertia that can be provided. Taking the analysis of single-phase SV as an example, this paper proposes a flexible inertia optimization method for single-phase VSIs based on the inertial characteristic of hold filter, which gives a new degree of freedom for the optimization of single-phase VSIs inertia. In this way, the inertia of single-phase VSIs can be adjusted more freely according to system requirements without affecting the frequency stability. Furthermore, the effects of the proposed method on the system dynamic characteristics are investigated. Finally, simulation and experimental results are given to verify the feasibility and feature of the proposed inertia optimization method.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Frequency and Voltage Tuning of Series–Series Compensated Wireless Power
           Transfer System to Sustain Rated Power Under Various Conditions
    • Authors: Yiming Zhang;Tianze Kan;Zhengchao Yan;Chunting Chris Mi;
      Pages: 1311 - 1317
      Abstract: In a wireless power transfer (WPT) system, voltage tuning and frequency tuning are two major methods to control the output power. For the design of a WPT system at the rated power, it is crucial to understand the characteristics of a WPT system with a constant-power load (CPL) under voltage tuning and frequency tuning. The model of a series-series compensated WPT system with a CPL is established based on the Thevenin equivalent circuits. The conditions to achieve the maximum coil-to-coil efficiency for the two tuning methods are obtained. For frequency tuning, the tuning zone above the resonant frequency is selected because of its wide tuning range and zero-voltage switching. The maximum output power at different operating frequencies is derived, and the required inverter dc voltage and the tuning range for a target output power can be obtained accordingly. With a strong coupling, the maximum efficiency of frequency tuning can be as high as that of voltage tuning; while with a weak coupling, the efficiency of frequency tuning is much smaller than that of voltage tuning. The model with a CPL is helpful for the design and optimization of a WPT system with the rated power.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Lyapunov Characterization and Analysis of the Operating Modes of the
           AC–DC Ćuk Converter
    • Authors: Nikola Ž. Petrović;Aleksandra Lekić;Dušan M. Stipanović;
      Pages: 1318 - 1328
      Abstract: In this paper, all operating modes of the ac-dc Cuk converter have been modeled as linear-time invariant systems where some of the modes were not only modeled but also detected for the first time. Another feature provided in this paper is that the converter can be modeled and analyzed as a switching dynamical system controlled by an external constant duty-ratio switching and the internal switchings shown to be related to the minimum among the time derivatives of a common quadratic Lyapunov function. Some representative simulations are provided to illustrate and validate the technical results of this paper.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Transformerless Hybrid Converter With AC and DC Outputs and Reduced
           Leakage Current
    • Authors: Somdut Dey;Vinod Kumar Bussa;R. K. Singh;
      Pages: 1329 - 1341
      Abstract: In photovoltaic (PV) generation systems, due to the high efficiency, compactness, and low costs, transformerless hybrid converters with ac and dc outputs have become popular in recent times. However, common-mode leakage current occurs in these converters when the converter neutral point is grounded or it is tied to the grid. The presence of leakage current causes considerable safety and electromagnetic interference problem along with the improper operation of safety devices. This paper proposes a transformerless hybrid converter capable to give simultaneous ac and dc outputs with reduced leakage current for the PV system. In order to ensure the reduced leakage current for all operating states (power, shoot through, and zero) of the proposed converter, a novel pulsewidth modulation (PWM) switching scheme is also introduced in this paper. As the proposed hybrid converter can provide both dc and ac outputs, it can supply both dc and ac loads simultaneously. The detailed steady state analysis and dynamic modeling of the proposed hybrid converter is carried and discussion on the developed PWM technique for reducing the leakage current is presented in this paper. A comparative analysis between the proposed and conventional converters is also carried out. The performance of the proposed algorithm is validated through experimental results.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • An Accurate Self-Commissioning Technique for Matrix Converters Applied to
           Sensorless Control of Synchronous Reluctance Motor Drives
    • Authors: Fausto Stella;Arzhang Yousefi-Talouki;Shafiq Odhano;Gianmario Pellegrino;Pericle Zanchetta;
      Pages: 1342 - 1351
      Abstract: The compensation of converters' nonlinear voltage error is crucial in the encoder-less control of ac motor drives. In this paper, a new self-commissioning and compensation method is proposed for matrix converters (MCs). Similar to what done in the past for voltage source inverters, the MC voltage error is identified before the drive start and stored in a lookup table, later used for error compensation and accurate voltage estimate. Different from what observed in the past, the effect of parasitic capacitors on nonlinear voltage error of MCs in four-step current-based commutation is observed and studied. Eventually, this method is applied to the sensorless control of a synchronous reluctance motor drive, using the direct flux vector control concept. Experimental results are presented to validate the effectiveness of the proposed self-commissioning in improving the performance of sensorless control at standstill and low speed.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Common Mode Voltage Reduction in a Single-Phase Quasi Z-Source Inverter
           for Transformerless Grid-Connected Solar PV Applications
    • Authors: Mohammad Meraj;Syed Rahman;Atif Iqbal;Lazhar Ben-Brahim;
      Pages: 1352 - 1363
      Abstract: The quasi-Z-source inverter (qZSI) is becoming a popular inverter topology that can buck or boost input voltage without a dc-dc converter and hence can be used in transformerless configuration. Due to its single-stage conversion, the qZSI can be used as an efficient transformerless grid-tie inverter. However, the common mode current is a major problem in transformerless topologies due to the absence of galvanic isolation. This paper proposes a modified pulsewidth modulation (PWM) technique to control the qZSI, along with two extra semiconductor switches, to reduce the common mode current. The proposed method offers an efficient solution for grid integration of solar photovoltaic systems. The proposed topology has the following features: 1) uses phase-leg shoot-through for boosting the dc voltage to the required level which eliminates the additional dc-dc converter; 2) eliminates the PWM deadtime and provides freewheeling through additionally connected switches; 3) minimizes the common mode current by modifying the PWM and adding additional switches at the output side of inverter; and 4) avoids the conduction of body diode of H-bridge which has poor reverse recovery characteristics. The proposed topology can efficiently control the reactive power, and the suitable PWM scheme is also reported. Simulation results have been performed with the Standard Test conditions of the photovoltaic panel. Experimental results for a single-phase 500-W prototype are presented to validate the proposed PWM scheme for the qZSI topology.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Modeling and Analysis of a Strongly Coupled Series–Parallel-Compensated
           Wireless Power Transfer System
    • Authors: Yiming Zhang;Zhengchao Yan;Tianze Kan;Xiaosheng Zeng;Shuangquan Chen;Chunting Chris Mi;
      Pages: 1364 - 1370
      Abstract: In the wireless charging of high-power electric buses or low-power consumer electronics, the charging distance is normally very small, leading to a strong coupling. Current distortion occurs for a wireless power transfer (WPT) system with a strong coupling. This paper investigates the strongly coupled series-parallel (SP)-compensated WPT system, where the first harmonic approximation (FHA) is no longer valid. A mathematical model of an SP-compensated WPT system based on differential equations is built. There are two sinusoidal components with significantly different frequencies existing in the transmitter and receiver currents, which cause the current distortion. The proposed model and FHA are compared, and the proposed model is more accurate than FHA. The estimations of the current root-mean-square values from FHA tend to be smaller than those from the proposed model and the measured values. In addition, it is found that with the increasing rectifier dc current, the system transits from zero voltage switching to zero current switching. The critical rectifier dc current decreases with the increasing operating frequency. The experimental results verify the effectiveness of the proposed model. The proposed model promotes a better design of an SP-compensated strongly coupled WPT system.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Investigating Impact of Emerging Medium-Voltage SiC MOSFETs on
           Medium-Voltage High-Power Industrial Motor Drives
    • Authors: Alinaghi Marzoughi;Rolando Burgos;Dushan Boroyevich;
      Pages: 1371 - 1387
      Abstract: The SiC MOSFETs are becoming game-changing devices in the field of power electronics, enabling higher temperatures, power densities, and efficiencies. However, at higher voltages than 1.7 kV, these semiconductors are at early stages of development and yet not commercialized. Based on the characterization results of the state-of-the-art 3.3-kV SiC MOSFETs, for the first time, this paper investigates the design and comparison of topologies commercially used for medium-voltage (MV) drives in 4.16-13.8-kV voltage range in the presence of MV SiC MOSFETs. For this purpose, the cascaded H-bridge, modular multilevel converter, and five-level active neutral point clamped (5-L ANPC) topologies are targeted. Design is carried out at 4.16-, 6.9-, and 13.8-kV voltages (4.16 and 6.9 kV in the case of 5-L ANPC) and 3and 5-MVA power ratings using commercial Si IGBTs as well as latest generation noncommercial 3.3-kV SiC MOSFETs, in order to enable investigation of impact from the emerging MV SiC MOSFETs on motor drive system. Selection of several voltage and power levels is to elucidate behavior of converters at a different voltage and power rating and determine the best option for given operating point. Based on design data, comparisons are done among the mentioned topologies from different points of view including efficiency, passive component requirement, semiconductor utilization, power density, low-speed operation capability, fault containment, and parts count. Experimental results on an H-bridge cell made with 3.3-kV SiC MOSFETs are brought to verify converter modeling in MATLAB environment as well as the conveyed thermal calculations.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • High-Efficiency Multiphase Capacitive Power Transfer in Sliding Carriages
           With Closed-Loop Burst-Mode Current Control
    • Authors: Jiejian Dai;Skyler S. Hagen;Daniel C. Ludois;
      Pages: 1388 - 1398
      Abstract: Sliding carriages or gantries that use journal bearings for support are common in industrial automation, e.g., assembly lines, spindle heads, and xy tables, and their moving parts are powered through a flexible wireway or cable track. This paper eliminates the cable connection by using the parasitic capacitance of the stock sliding bearings to capacitively transfer power between stationary and moving parts. At high frequency, ac current can safely pass through the journal-rail capacitance where it is ultimately rectified on a carriage/gantry for final use. A 3.4-MHz resonant voltage sourced inverter utilizing gallium nitride (GaN) high-electron mobility transistors in a three-phase configuration enables this approach. The salient features of this paper are: 1) characterization of commercial-off-the-shelf bearings; 2) development of a three-phase matching network between the tank circuit and GaN inverter for high efficiency; and 3) control of the dc output current on the secondary (moving carriage/gantry) side using only primary (stationary) side sensed quantities and burst-mode control. A controller developed from a small signal operating point model uses average bearing displacement current, measured by ac sense coils embedded in the tank inductors, to accurately regulate dc output current. The experimental tests at a tank resonance of 3.4 MHz demonstrate 100-W power transfer through an off-the-shelf bearing to a sliding carriage load with 95% efficiency. This system, when paired with a burst-mode frequency of 10 kHz, demonstrates current regulation on the carriage load with a bandwidth of 200 Hz.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Voltage-Sensor-Based MPPT for Stand-Alone PV Systems Through Voltage
           Reference Control
    • Authors: Muralidhar Killi;Susovon Samanta;
      Pages: 1399 - 1407
      Abstract: A single voltage-sensor-based maximum power point tracking (MPPT) controller with improved tracking performance is presented in this paper. The MPPT controller can be implemented by either direct duty cycle or voltage reference control in conjunction with a proportional and integral (PI) controller. The voltage reference control has the advantages of faster convergence and small oscillations in steady state compared with the direct duty cycle method. Moreover, the controller gains can be analytically calculated unlike trial-and-error-based selection of scaling factors for the direct duty cycle method. Thus, voltage-sensor-based MPPT algorithm through a voltage reference control technique with the help of the PI controller is developed for minimizing the tracking time and steady-state oscillations. Selection of the objective function to mitigate the drawbacks associated with the voltage-sensor-based algorithm for a decrease in solar irradiance is also demonstrated. The tracking performance of the proposed algorithm is tested through simulation and experimentation of the designed prototype.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
  • Autotuning Technique for the Cost Function Weight Factors in Model
           Predictive Control for Power Electronic Interfaces
    • Authors: Mohammad B. Shadmand;Sarthak Jain;Robert S. Balog;
      Pages: 1408 - 1420
      Abstract: This paper presents an autotuning technique for the online selection of the cost function weight factors in model predictive control (MPC). The weight factors in the cost function with multiple control objectives directly affect the performance and robustness of the MPC. The proposed method in this paper determines the optimum weight factors of the cost function for each sampling time; the optimization of the weight factors is done based on the prediction of the absolute tracking error of the control objectives and the corresponding constraints. The proposed method eliminates the need of the trial-and-error approach to determine a fixed weight factor in the cost function. The application considered is a capacitor-less static synchronous compensator based on the MPC of a direct matrix converter. This technique compensates lagging power factor loads using inductive energy storage elements instead of electrolytic capacitors. The result demonstrates that the proposed autotuning approach of cost function weights makes the control algorithm robust to parameter variation and other uncertainties in the system. The proposed capacitor-less reactive power compensator based on the autotuned MPC cost function weight factor is verified experimentally.
      PubDate: June 2019
      Issue No: Vol. 7, No. 2 (2019)
       
 
 
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