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  Subjects -> ELECTRONICS (Total: 175 journals)
Showing 1 - 200 of 277 Journals sorted alphabetically
Acta Electronica Malaysia     Open Access  
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 7)
Advances in Electrical and Electronic Engineering     Open Access   (Followers: 5)
Advances in Electronics     Open Access   (Followers: 76)
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: 305)
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: 35)
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: 44)
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: 253)
Edu Elektrika Journal     Open Access   (Followers: 1)
Electrica     Open Access  
Electronic Design     Partially Free   (Followers: 104)
Electronic Markets     Hybrid Journal   (Followers: 7)
Electronic Materials Letters     Hybrid Journal   (Followers: 4)
Electronics     Open Access   (Followers: 85)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 10)
Electronics For You     Partially Free   (Followers: 91)
Electronics Letters     Hybrid Journal   (Followers: 26)
Elkha : Jurnal Teknik Elektro     Open Access  
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 50)
Energy Harvesting and Systems     Hybrid Journal   (Followers: 4)
Energy Storage Materials     Full-text available via subscription   (Followers: 2)
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: 185)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IACR Transactions on Symmetric Cryptology     Open Access  
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 96)
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: 65)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 69)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 55)
IEEE Transactions on Circuits and Systems for Video Technology     Hybrid Journal   (Followers: 19)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 39)
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: 11)
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: 45)
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: 57)
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 24)
Informatik-Spektrum     Hybrid Journal   (Followers: 2)
Instabilities in Silicon Devices     Full-text available via subscription   (Followers: 1)
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 12)
International Journal of Advanced Research in Computer Science and Electronics Engineering     Open Access   (Followers: 18)
International Journal of Advances in Telecommunications, Electrotechnics, Signals and Systems     Open Access   (Followers: 10)
International Journal of Antennas and Propagation     Open Access   (Followers: 11)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 5)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 6)
International Journal of Control     Hybrid Journal   (Followers: 12)
International Journal of Electronics     Hybrid Journal   (Followers: 7)
International Journal of Electronics and Telecommunications     Open Access   (Followers: 13)
International Journal of Granular Computing, Rough Sets and Intelligent Systems     Hybrid Journal   (Followers: 2)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Image, Graphics and Signal Processing     Open Access   (Followers: 14)
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 8)
International Journal of Nano Devices, Sensors and Systems     Open Access   (Followers: 12)
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields     Hybrid Journal   (Followers: 4)
International Journal of Power Electronics     Hybrid Journal   (Followers: 24)
International Journal of Review in Electronics & Communication Engineering     Open Access   (Followers: 4)
International Journal of Sensors, Wireless Communications and Control     Hybrid Journal   (Followers: 10)
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 4)
International Journal of Wireless and Microwave Technologies     Open Access   (Followers: 6)
International Transaction of Electrical and Computer Engineers System     Open Access   (Followers: 2)
JAREE (Journal on Advanced Research in Electrical Engineering)     Open Access  
Journal of Biosensors & Bioelectronics     Open Access   (Followers: 3)
Journal of Advanced Dielectrics     Open Access   (Followers: 1)
Journal of Artificial Intelligence     Open Access   (Followers: 10)
Journal of Circuits, Systems, and Computers     Hybrid Journal   (Followers: 4)
Journal of Computational Intelligence and Electronic Systems     Full-text available via subscription   (Followers: 1)
Journal of Electrical and Electronics Engineering Research     Open Access   (Followers: 23)
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 Field Robotics     Hybrid Journal   (Followers: 2)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 162)
Journal of Information and Telecommunication     Open Access   (Followers: 1)
Journal of Intelligent Procedures in Electrical Technology     Open Access   (Followers: 3)
Journal of Low Power Electronics     Full-text available via subscription   (Followers: 7)
Journal of Low Power Electronics and Applications     Open Access   (Followers: 9)
Journal of Microelectronics and Electronic Packaging     Hybrid Journal  
Journal of Microwave Power and Electromagnetic Energy     Hybrid Journal  
Journal of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 10)
Journal of Nuclear Cardiology     Hybrid Journal  
Journal of Optoelectronics Engineering     Open Access   (Followers: 4)
Journal of Physics B: Atomic, Molecular and Optical Physics     Hybrid Journal   (Followers: 28)
Journal of Power Electronics & Power Systems     Full-text available via subscription   (Followers: 11)
Journal of Semiconductors     Full-text available via subscription   (Followers: 5)
Journal of Sensors     Open Access   (Followers: 26)
Journal of Signal and Information Processing     Open Access   (Followers: 9)
Jurnal Rekayasa Elektrika     Open Access  
Jurnal Teknik Elektro     Open Access  
Kinetik : Game Technology, Information System, Computer Network, Computing, Electronics, and Control     Open Access  
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Magnetics Letters, IEEE     Hybrid Journal   (Followers: 7)
Majalah Ilmiah Teknologi Elektro : Journal of Electrical Technology     Open Access   (Followers: 2)
Metrology and Measurement Systems     Open Access   (Followers: 5)
Microelectronics and Solid State Electronics     Open Access   (Followers: 18)
Nanotechnology Magazine, IEEE     Full-text available via subscription   (Followers: 33)
Nanotechnology, Science and Applications     Open Access   (Followers: 6)
Nature Electronics     Hybrid Journal  
Networks: an International Journal     Hybrid Journal   (Followers: 6)
Open Journal of Antennas and Propagation     Open Access   (Followers: 8)
Optical Communications and Networking, IEEE/OSA Journal of     Full-text available via subscription   (Followers: 15)
Paladyn. Journal of Behavioral Robotics     Open Access   (Followers: 1)
Power Electronics and Drives     Open Access   (Followers: 1)
Problemy Peredachi Informatsii     Full-text available via subscription  
Progress in Quantum Electronics     Full-text available via subscription   (Followers: 7)
Pulse     Full-text available via subscription   (Followers: 5)
Radiophysics and Quantum Electronics     Hybrid Journal   (Followers: 2)
Recent Advances in Communications and Networking Technology     Hybrid Journal   (Followers: 3)
Recent Advances in Electrical & Electronic Engineering     Hybrid Journal   (Followers: 9)
Research & Reviews : Journal of Embedded System & Applications     Full-text available via subscription   (Followers: 5)
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 53)
Semiconductors and Semimetals     Full-text available via subscription   (Followers: 1)
Sensing and Imaging : An International Journal     Hybrid Journal   (Followers: 2)
Services Computing, IEEE Transactions on     Hybrid Journal   (Followers: 4)
Software Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 75)
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 13)
Solid-State Electronics     Hybrid Journal   (Followers: 9)
Superconductor Science and Technology     Hybrid Journal   (Followers: 2)
Synthesis Lectures on Power Electronics     Full-text available via subscription   (Followers: 3)
Technical Report Electronics and Computer Engineering     Open Access  
TELE     Open Access  
Telematique     Open Access  
TELKOMNIKA (Telecommunication, Computing, Electronics and Control)     Open Access   (Followers: 8)
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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Journal Cover
IEEE Transactions on Power Electronics
Journal Prestige (SJR): 2.215
Citation Impact (citeScore): 9
Number of Followers: 70  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0885-8993
Published by IEEE Homepage  [191 journals]
  • IEEE Power Electronics Society
    • Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • IEEE Power Electronics Society
    • Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Administrative committee
    • Abstract: Presents a listing of the PES society Administrative committee.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Reconfigurable Intermediate Resonant Circuit Based WPT System With
           
    • Authors: Yong Li;Jiefeng Hu;Ming Liu;Yang Chen;Ka Wing Chan;Zhengyou He;Ruikun Mai;
      Pages: 1988 - 1992
      Abstract: In this letter, a compact battery charger based on wireless power transfer (WPT) technology without any communication requirement is proposed. Here, a new intermediate coil is developed to achieve load-independent constant current (CC) and constant voltage (CV) outputs. The intermediate coil is split into two coils and is overlapped with the receiver coil to form a compact structure. Two switches on the receiver side are used to reconfigure the intermediate resonant circuit in order to select different charging modes, i.e., CC mode or CV mode. The communication between the transmitter side and the receiver side as well as complex control strategies is not needed in the proposed structure. Besides, the proposed system can achieve zero phase angle operation, fixed operating frequency, and zero-voltage switching, which not only can lower the power rating of power devices but also improve the efficiency. A laboratory prototype with a 3.6 A charging current and a 48 V charging voltage is built to verify the feasibility of the proposed method.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Heterogeneous Integration of GaN and BCD Technologies and Its Applications
           to High Conversion-Ratio DC–DC Boost Converter IC
    • Authors: Fanyi Meng;Don Disney;Bei Liu;Yildirim Baris Volkan;Ao Zhou;Zhipeng Liang;Xiang Yi;Susai Lawrence Selvaraj;Lulu Peng;Kaixue Ma;Chirn Chye Boon;
      Pages: 1993 - 1996
      Abstract: This letter presents a novel technology for the integration of gallium nitride (GaN) power devices with silicon control circuits. It comprises stacked GaN power transistors and bipolar-CMOS-double-diffused metal-oxide-semiconductor (DMOS) (BCD) circuits. It leverages on both advantages of the high-voltage low-loss GaN devices and the high-integration BCD circuits. Using conventional manufacturing, packaging, and assembly techniques and equipment, the proposed technology is technology transferrable and applicable for commercial power electronic applications. To validate the concept, a 3.3–70 V dc–dc boost converter is designed, implemented, and verified experimentally. It features a conversion efficiency of 70.3%, output power of 1.68 W, and compact size of ${text{0.32}}times {text{0.18}},{text{cm}}^{2}$.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • $^circ$ C+SiC+PWM+Integrated+Circuit&rft.title=IEEE+Transactions+on+Power+Electronics&rft.issn=0885-8993&rft.date=2019&rft.volume=34&rft.spage=1997&rft.epage=2001&rft.aulast=Zetterling;&rft.aufirst=Saleh&rft.au=Saleh+Kargarrazi;Hossein+Elahipanah;Stefano+Saggini;Debbie+Senesky;Carl-Mikael+Zetterling;">500  $^circ$ C SiC PWM Integrated Circuit
    • Authors: Saleh Kargarrazi;Hossein Elahipanah;Stefano Saggini;Debbie Senesky;Carl-Mikael Zetterling;
      Pages: 1997 - 2001
      Abstract: This letter reports on a high-temperature pulsewidth modulation (PWM) integrated circuit microfabricated in 4H-SiC bipolar process technology that features an on-chip integrated ramp generator. The circuit has been characterized and shown to be operational in a wide temperature range from 25 to 500 $^circ$C. The operating frequency of the PWM varies in the range of 160  to  210 kHz and the duty cycle varies less than 17% over the entire temperature range. The proposed PWM is suggested to efficiently and reliably control power converters in extreme environments.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Single Gate Driver Based Solid-State Circuit Breaker Using Series
           Connected SiC MOSFETs
    • Authors: Yu Ren;Xu Yang;Fan Zhang;Fred Wang;Leon M. Tolbert;Yunqing Pei;
      Pages: 2002 - 2006
      Abstract: Semiconductor devices based solid-state circuit breakers (SSCBs) are promising in the dc power distribution system as protective equipment for their ultrashort action time. This letter proposes a topology of SSCB using series connected silicon carbide (SiC) metal oxide semiconductor field effect transistors (mosfets), which only requires a single isolated gate driver. The SSCB has very low cost and high reliability because it only has 13 components including passive components and diodes apart from two SiC mosfets to achieve both balanced voltage distribution during short-circuit interruption duration and reliable positive gate voltage during on-state. The SSCB prototype is built and experimentally verified to interrupt 75 A short-circuit current under the dc-bus voltage of 1200 V within 1.5 μs.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Model Predictive Torque and Flux Control Minimizing Current Distortions
    • Authors: Petros Karamanakos;Tobias Geyer;
      Pages: 2007 - 2012
      Abstract: A new model predictive torque and flux controller is proposed, which controls the electromagnetic torque and rotor (rather than the stator) flux magnitude. Analytical expressions for the weighting factors are derived that ensure that the proposed controller achieves the same closed-loop performance as predictive current control. In particular, the same low current and torque distortions result, without requiring an outer field-oriented control loop.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Uniform Power IPT System With Three-Phase Transmitter and Bipolar Receiver
           for Dynamic Charging
    • Authors: Hongchao Li;Yeran Liu;Kunzhuo Zhou;Zhengyou He;Weihua Li;Ruikun Mai;
      Pages: 2013 - 2017
      Abstract: Dynamic inductive power transfer (DIPT) system has attracted a lot of attention from researchers, as it can reduce charging anxiety and extend the distance traveled for electric vehicles. Power fluctuation is one of the toughest drawbacks for DIPT because of the coupling coefficient's variation between the transmitters and receivers. In order to overcome this, a three-phase inverter based DIPT with a single-phase receiver is proposed to get a constant voltage gain by being reversed connected to double D coil. The length of the receiver coil is optimized to decrease the variation of the equivalent of mutual inductances by three-dimensional (3-D) finite-element analysis tool ANSYS MAXWELL. A 500 W DIPT prototype is established based on the optimized coil structure to evaluate the proposed approach. The results show that the variation of the output voltage is within $ pm text{1.17}% $ during various positions. The overall dc/dc system efficiency is from 92.02% up to 93.41%.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • An Adaptive Frequency Optimization Scheme for LLC Converter With
           Adjustable Energy Transferring Time
    • Authors: Ting Qian;Chenghui Qian;
      Pages: 2018 - 2024
      Abstract: This letter proposes a new frequency optimization scheme for LLC converters with adjustable energy transferring time. The output voltage is regulated by simultaneous adjustment of the resonant time and the switching frequency. Meanwhile, the concept of adaptive current injection is borrowed to solve the problem of difficult control regulation when only a narrow frequency range is allowed. Therefore, in comparison to a scheme that keeps the switching frequency constant, the new scheme does not add any additional circuit. The advantage is that higher power efficiency is achievable, since the conduction loss is significantly reduced by actively controlling the switching cycle with respect to the variation of resonant time. In addition, since the frequency range is narrow, a lower ratio between the leakage inductance and the magnetizing inductance is still allowed. In addition to detailed theoretical analysis, experimental results verify the feasibility and effectiveness of the proposed concept.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • $LLC$ +Resonant+Converters:+Analysis+and+Trigonometric+Current+Balancing&rft.title=IEEE+Transactions+on+Power+Electronics&rft.issn=0885-8993&rft.date=2019&rft.volume=34&rft.spage=2025&rft.epage=2038&rft.aulast=Botting;&rft.aufirst=Sayed&rft.au=Sayed+Abbas+Arshadi;Martin+Ordonez;Wilson+Eberle;Mohammad+Ali+Saket;Marian+Craciun;Chris+Botting;">Unbalanced Three-Phase $LLC$ Resonant Converters: Analysis and
           Trigonometric Current Balancing
    • Authors: Sayed Abbas Arshadi;Martin Ordonez;Wilson Eberle;Mohammad Ali Saket;Marian Craciun;Chris Botting;
      Pages: 2025 - 2038
      Abstract: Three-phase $LLC$ resonant converters can handle very high power levels beyond the capabilities of half-bridge and full-bridge $LLC$ topologies. Among other characteristics, three-phase $LLC$ structures reduce output current ripple (small output filter), enable parallel power processing (low peak current), and provide good thermal distribution. However, all these key advantages can be severely compromised due to passive components tolerances, leading to undesired current balance issues in three-phase $LLC$ resonant converters. Tolerances in resonant tank passive components are inevitable and lead to unequal peak currents between phases, uneven temperature distribution, and large output current ripple. This paper investigates the imbalances in three-phase $LLC$ converters and proposes a novel trigonometric current balancing (TCB) technique using phasor analysis. In this strategy, the required input voltage phase angles are calculated to achieve balanced phase currents, even under severe unbalanced conditions. In some cases, the output filter current ripple is reduced to less than half. The methodology is verified with a 3-kW experimental prototype, which validates the analytical framework and effectiveness of TCB.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Power-Based Droop Control in DC Microgrids Enabling Seamless Disconnection
           From Upstream Grids
    • Authors: Guangyuan Liu;Tommaso Caldognetto;Paolo Mattavelli;Paolo Magnone;
      Pages: 2039 - 2051
      Abstract: This paper proposes a local power-based droop controller for distributed energy resource converters in dc microgrids that are connected to upstream grids by grid-interface converters. During normal operation, the grid-interface converter imposes the microgrid bus voltage, and the proposed controller allows power flow regulation at distributed energy resource converters’ output. On the other hand, during abnormal operation of the grid-interface converter (e.g., due to faults in the upstream grid), the proposed controller allows bus voltage regulation by droop control. Notably, the controller can autonomously convert from power flow control to droop control, without any need of bus voltage variation detection schemes or communication with other microgrid components, which enables seamless transitions between these two modes of operation. Considering distributed energy resource converters employing the power-based droop control, the operation modes of a single converter and of the whole microgrid are defined and investigated herein. The controller design is also introduced. Furthermore, the power sharing performance of this control approach is analyzed and compared with that of classical droop control. The experimental results from a laboratory-scale dc microgrid prototype are reported to show the final performances of the proposed power-based droop control.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Stability Analysis for the Grid-Connected Single-Phase Asymmetrical
           Cascaded Multilevel Inverter With SRF-PI Current Control Under Weak Grid
           Conditions
    • Authors: Yang Han;Hao Chen;Zipeng Li;Ping Yang;Lin Xu;Josep M. Guerrero;
      Pages: 2052 - 2069
      Abstract: This paper analyzes the influence of phase-locked loop (PLL) on the stability of LCL-type single-phase grid-connected asymmetrical cascaded H-bridge multilevel inverter (ACHMI) with synchronous reference frame proportional-integral (SRF-PI) grid current control under weak grid scenarios. The ACHMI system is composed of power stage circuit and control system, where the control system contains the dual-loop current control strategy established in the hybrid reference frame, the SRF-PLL, and the hybrid modulation method employed to synthesize the multilevel output voltage. The small-signal model of the whole ACHMI system is first established by using a simple step-by-step derivation method, and then, the small-signal analysis method is adopted to linearize the ACHMI, which is then utilized to derive the impedance model of the ACHMI system. Furthermore, an improved impedance stability criterion is derived, which is then employed to analyze the system stability. By using this criterion, the stability of the ACHMI can be evaluated with the variation of the bandwidth of PLL, the output power factor angle of the ACHMI, and the amplitude of the grid current reference signal under weak grid conditions. In this paper, a systematic design procedure for the optimal selection of the PI controller of the PLL is presented, which guarantees the steady-state performance and dynamic response of the ACHMI system. With this design method, the dual-loop current control and PLL can be taken into account simultaneously when analyzing the stability margin of the ACHMI. Finally, the simulation and experimental results from a down-scaled grid-connected ACHMI prototype system are provided to confirm the validity of theoretical analysis.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Reduced Switch Hybrid Multilevel Unidirectional Rectifier
    • Authors: Debranjan Mukherjee;Debaprasad Kastha;
      Pages: 2070 - 2081
      Abstract: Nonregenerative pulsewidth-modulated (PWM) rectifiers are increasingly being considered for applications, where the power flow is unidirectional, such as power supplies for telecommunications, X-ray, the machine-side converter for wind energy conversion systems, etc. They use fewer active switches, which increase their power density and reduce cost. This paper proposes a novel reduced switch topology for a multilevel (five-level or higher) nonregenerative PWM rectifier. It uses only four controlled switches and eight diodes per phase for a five-level rectifier. Half of the diodes are naturally commutated (zero current switching) at the line frequency, which reduces switching losses. This topology has several other advantages compared to similar topologies reported in the literature, such as minimum voltage stress across the devices, elimination of transient voltage-balancing snubbers, no extra hardware for balancing the flying capacitors, the dc-link mid-point voltage, etc. In this paper, switching cycle average modeling and the carrier-based modulation strategy for this rectifier are also presented to maintain a balanced dc link and to regulate flying capacitor voltages, while achieving unity displacement factor at the rectifier input terminals. The overall performance of the rectifier is verified by experimental results.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A New Hybrid Multilevel DC–AC Converter With Reduced Energy Storage
           Requirement and Power Losses for HVDC Applications
    • Authors: Jie Yang;Zhiyuan He;Jinkun Ke;Minhua Xie;
      Pages: 2082 - 2096
      Abstract: A dc–ac converter for voltage-source converter (VSC)-HVdc technology has a significant influence on the performance of the entire power transmission system. This paper introduces a new dc–ac converter composed of submodules and series insulated-gate bipolar transistor (IGBT) switches. The basic idea of this hybrid solution is to shape the ac voltage by submodules but, per half cycle, reconnect them to different electrical points by IGBT switches. This concept can help to reduce the quantities of submodules, thereby reducing the energy storage requirement significantly. Another advantage is that the IGBT switches can be soft switched by utilizing the high controllability of the submodules. This brings extra benefit of power losses reduction. In this paper, the operating principle of this hybrid converter is explained. Its performances are also presented in detail and compared with those popular VSC dc–ac converters. The feasibility of the new concept is also verified by simulation and experimental results.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Multiresonant Power Converter for Improved Dual-Frequency Induction
           Heating
    • Authors: Héctor Sarnago;Oscar Lucía;Jose M. Burdio;
      Pages: 2097 - 2103
      Abstract: Industrial induction heating (IH) is a key manufacturing process due to its benefits in terms of efficiency, accurate output power control, and high performance. These features have made possible the extension of this technology to a wide range of industries from automotive to aeronautic, domestic, or renewable energies. One of the main challenges still present is the design of a high-performance and cost-effective process for those induction targets with complex geometries exposed to the magnetic field, being the most representative example gears present in most mechanical systems. Usually, in order to optimize the heating process, multifrequency IH systems are used, being often expensive and/or difficult to tune and control. The aim of this paper is, consequently, to propose a family of power converters able to supply the inductor system with two simultaneous frequencies in order to improve the heating process of the induction target. The proposed converter takes advantage of a multiresonant network allowing full control of the output power delivered at each frequency and, at the same time, a compact and cost-effective implementation. The proposed converter is analyzed, designed, and implemented, and experimental verification of its operation is provided in this paper.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Single-Stage Capacitive AC-Link AC–AC Power Converter
    • Authors: Ehsan Afshari;Masih Khodabandeh;Mahshid Amirabadi;
      Pages: 2104 - 2118
      Abstract: A single-stage three-phase ac–ac converter benefiting from a high-frequency alternating link voltage is proposed in this paper. In this converter, a very small film capacitor can transfer the energy from the input to the output, owing to the high-frequency alternating voltage of the link. This eliminates the need for large electrolytic capacitors that are typically used in dc-link ac–ac converters. Moreover, a compact high-frequency transformer at the link can replace the bulky low-frequency transformers, in case isolation is required. These features increase the power density as well as reliability of the proposed converter in comparison with the conventional dc-link converters. The number of required switches in the proposed converter is 12, which is less than the number of switches needed in matrix converters, leading to lower switching and conduction losses. Despite being single-stage, the proposed ac–ac converter is capable of both stepping up and stepping down the voltage and also frequency transformation. This eliminates the need for using cascaded power converters. In this paper, the operation principles of the proposed ac–ac converter are investigated, and variable switching frequency and fixed switching frequency control methods for operating this converter are introduced. The performance of the converter is verified through simulation and experiment.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Modified DC Power Electronic Transformer Based on Series Connection of
           Full-Bridge Converters
    • Authors: Jiepin Zhang;Jianqiang Liu;Jingxi Yang;Nan Zhao;Yang Wang;Trillion Q. Zheng;
      Pages: 2119 - 2133
      Abstract: This paper proposes a novel dc power electronic transformer (DCPET) topology for locomotive, ac/dc hybrid grid, dc distribution grid, and other isolated medium-voltage and high-power applications. Compared with conventional PET topology, the proposed DCPET has fewer power semiconductor devices and high-frequency isolation transformers, which can improve the power density and reliability. Fault handling or redundancy design can be achieved to further improve the reliability when some dc–dc modules break down. Also, input voltage sharing control can be omitted to simplify the control system and improve the stability. Meanwhile, soft switching is guaranteed for all the switches, which is beneficial to increase switching frequency and improve power density. In this paper, the principle, evolution, and control of the proposed DCPET are respectively presented and studied in detail. Finally, a prototype of the proposed DCPET is built and the experimental results verify the validity and superiority of the proposed topology.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Harmonic State-Space Based Small-Signal Impedance Modeling of a Modular
           Multilevel Converter With Consideration of Internal Harmonic Dynamics
    • Authors: Jing Lyu;Xin Zhang;Xu Cai;Marta Molinas;
      Pages: 2134 - 2148
      Abstract: The small-signal impedance modeling of a modular multilevel converter (MMC) is the key for analyzing resonance and stability of MMC-based power electronic systems. The MMC is a power converter with a multifrequency response due to its significant steady-state harmonic components in the arm currents and capacitor voltages. These internal harmonic dynamics may have great influence on the terminal characteristics of the MMC, which, therefore, are essential to be considered in the MMC impedance modeling. In this paper, the harmonic state-space (HSS) modeling approach is first introduced to characterize the multiharmonic coupling behavior of the MMC. On this basis, the small-signal impedance models of the MMC are then developed based on the proposed HSS model of the MMC, which are able to include all the internal harmonics within the MMC, leading to accurate impedance models. Besides, different control schemes for the MMC, such as open-loop control, ac voltage closed-loop control, and circulating current closed-loop control, have also been considered during the modeling process, which further reveals the impact of the MMC internal dynamics and control dynamics on the MMC impedance. Furthermore, an impedance-based stability analysis of the MMC-high-voltage direct current connected wind farm has been carried out to show how the HSS-based MMC impedance model can be used in practical system analysis. Finally, the proposed impedance models are validated by both simulation and experimental measurements.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A New Single DC Source Six-Level Flying Capacitor Based Converter With
           Wide Operating Range
    • Authors: Javad Ebrahimi;Hamidreza Karshenas;
      Pages: 2149 - 2158
      Abstract: This paper presents a new six-level flying capacitor based (FC-based) multilevel converter with one dc source and the capability of operating in all power factors and modulation indexes. Multilevel converters with one dc voltage source are attractive in many applications as they do not need rather expensive and bulky multiwinding input transformer connection at the dc side. On the other hand, not all classic multilevel converters with one dc source can produce any desirable number of output voltage levels at all power factors and/or modulation indexes. In this paper, a hybrid structure is proposed in which six voltage levels can be realized at the ac terminals. The modulation technique and the control strategy for the FC voltage balancing are presented. To show the advantages of the proposed converter, different performance criteria, such as switch count and rating, the size of capacitors, switching frequency, and power losses, are compared with other existing six-level topologies. The results indicate that the proposed structure is superior to other six-level converters from different standpoints. Simulation results are used to further evaluate the performance of the proposed converter. A laboratory-type experimental setup is used to validate the theoretical results.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Hybrid Nine-Level, 1-φ Grid Connected Multilevel Inverter With Low
           Switch Count and Innovative Voltage Regulation Techniques Across Auxiliary
           Capacitor
    • Authors: Chamarthi Phanikumar;Jibanesh Roy;Vivek Agarwal;
      Pages: 2159 - 2170
      Abstract: A 1-φ hybrid nine-level inverter (H9LI) topology has been proposed in this paper. The proposed H9LI topology uses a simple phase disposition pulsewidth modulation strategy to generate nine-voltage levels in the output. The main advantage of this topology is that it has a low switch count (ten switches) compared to the existing nine-level inverter topologies. To regulate the voltage across auxiliary capacitor, two innovative control techniques are proposed, which are integrated with the inverter modulation technique itself. Hence, it does not require any extra voltage balancing circuits to maintain the voltage across the auxiliary capacitor and input dc capacitors. A major advantage of these control techniques is that they eliminate the sensing of the coupled inductor current. Another significant advantage of H9LI is that loss distribution among all the power switches is more uniform compared to existing nine-level inverters. Due to low part count and absence of extra voltage balancing circuits, the H9LI achieves higher efficiency (η ≍ 94.5%) and lower cost. Furthermore, the requirement of filter size reduces due to the presence of coupled inductor in H9LI. The proposed 1-φ grid connected H9LI is verified through MATLAB/Simulink simulations and validated through experiments on a laboratory prototype of 400-VA rating.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Constant ΔTj Power Cycling Strategy in DC Mode for Top-Metal and
           Bond-Wire Contacts Degradation Investigations
    • Authors: Son-Ha Tran;Zoubir Khatir;Richard Lallemand;Ali Ibrahim;Jean-Pierre Ousten;Jeffrey Ewanchuk;Stefan V. Mollov;
      Pages: 2171 - 2180
      Abstract: The study of the impact of junction temperature swings (ΔTj) on degradation mechanisms during power cycling tests (PCTs) requires both a control of the applied thermal stress and a separation of degradation modes. The first requirement can be obtained by using a “constant ΔTj” power cycling strategy that allows to minimize the cross interactions between the influencing factors. The second one is made by using a dedicated power module well suited for targeting only the chips top-side degradations (metallization and bond-wire contacts). In this paper, a constant ΔTj strategy by gate voltage regulation is performed for PCTs in the dc mode. The tested modules are ideally designed for top-metal and bond-wire contacts degradation investigations. From aging indicator on the collector–emitter voltage (VCE), the results clearly show that three regimes of degradation occur systematically at the insulated gate bipolar transistor (IGBT) chips top side, whatever the stress conditions. Moreover, comparative results in “constant ΔTj” and conventional “constant ΔI” PCT strategies have shown that the feedback between stresses and damages encountered in the second strategy is more important for low ΔTj values than for high ΔTj values. In addition, results show that in case of high stresses, the “constant ΔTj” strategy with VGE regulation gives values close to a “constant ΔI” strategy but that the extrapolation toward low values of ΔTj can be questionable for the “constant ΔTj” strategy.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Multiobjective Dynamic Voltage Restorer With Modified EPLL Control and
           Optimized PI-Controller Gains
    • Authors: Talada Appala Naidu;Sabha Raj Arya;Rakesh Maurya;
      Pages: 2181 - 2192
      Abstract: This paper describes a control algorithm based on modified enhanced phase-locked loop (MEPLL) in dynamic voltage restorer (DVR). It compensates distortions and unbalances in the supply voltage along with voltage sag/swell. Three-phase MEPLL extracts the fundamental positive-, negative-, and zero-sequence components from the distorted/unbalanced signals. Further fundamental positive-sequence components are used in the reference load voltage calculations. In addition to track the angle of the input signals similar to the conventional PLLs, the proposed algorithm (MEPLL) offers features of getting fundamental and sequential components in case of distorted or unbalanced grid voltage for all the three phases simultaneously. Optimization approach named as autonomous groups particle swarm optimization, a variant of PSO is used for the calculation of PI-controller gains. The integrated time square error is used as a cost function for optimization of an error between the reference and actual values. This approach of tuning PI gains improves the performance by eliminating the manual process. The proposed control algorithm is implemented in DVR system using MATLAB software and validated in a laboratory environment. The performance shows that the proposed control algorithm gives time effective and satisfactory solution for the unpredictable issues mentioned.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Cluster Voltage Regulation Strategy to Eliminate Negative-Sequence
           Currents Under Unbalanced Grid for Star-Connected Cascaded H-Bridge
           STATCOM
    • Authors: Daorong Lu;Sen Wang;Jianhui Yao;Tianyu Yang;Haibing Hu;
      Pages: 2193 - 2205
      Abstract: Under unbalanced grid, three cluster voltages are typically controlled balanced and unchanged for the star-connected cascaded H-bridge static synchronous compensator (CHB STATCOM), however, to deal with the unbalanced grid voltages, the modulation voltages become unbalanced, which would result in fewer steps of the staircase voltages and unbalanced double-line-frequency ripples across the cluster voltages. Thus, the harmonic performance of the currents is deteriorated. In addition, the negative sequence currents are always injected for active power redistribution, which degrades the power quality. To improve the current performance under the unbalanced grid, three cluster voltages are regulated to different values and three-phase modulation voltages can maintain balance. Based on this concept, three cluster voltages can be derived by decomposing the positive- and negative-sequence components from the converter voltages to meet the balance of three-phase currents. To ensure the cluster voltages stable, the zero-sequence voltage is further extracted to analyze the active power distribution. It is interesting to find that the total active power in each phase induced by both the negative and zero-sequence voltages is equal to zero, which reveals the CHB STATCOM has the natural zero-active-power feature. To keep three unequal cluster voltages within a certain boundary, the relationship between the unbalanced grid voltages and the cluster voltages is established, based on which the algorithm of limiting the cluster voltages is proposed. The theoretical analysis and the proposed control scheme are verified by the simulation and experimental results.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Three-Phase Custom Power Active Transformer for Power Flow Control
           Applications
    • Authors: M. A. Elsaharty;J. Rocabert;Jose Ignacio Candela;Pedro Rodriguez;
      Pages: 2206 - 2219
      Abstract: This paper presents the three-phase custom power active transformer (CPAT), characterized by the integration of power electronics in a transformer to facilitate grid services. Such integration enables step-up/step-down transformation between primary and secondary as well as shunt and series compensation services to the power system through a single transformer. The CPAT can empower the grid with flexible ac transmission system and power quality services such as power flow control, reactive power compensation, active filter, and voltage regulation through a single monolithic transformer. In this paper, designs of the three-phase CPAT are realized and analyzed based on their equivalent magnetic circuit as well as their structure requirements and constraints. Simulation analysis of the three-phase CPAT clarifies its capability to actively regulate power flow between the primary and secondary windings as well as achieve grid harmonic current compensation. Moreover, through real-time simulations and an experimental prototype, the merits and performance of the three-phase CPAT were further validated.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Generalized Associated Discrete Circuit Model of Power Converters in
           Real-Time Simulation
    • Authors: Keyou Wang;Jin Xu;Guojie Li;Nengling Tai;Anping Tong;Junxian Hou;
      Pages: 2220 - 2233
      Abstract: Power converters in the system-level real-time simulation are usually emulated by L/C-based associated discrete circuit (L/C-ADC). However, the L/C-ADC approaches may suffer from two issues: How to mitigate the unacceptable virtual power loss especially in high-frequency applications, and how to tune LC parameters setting which is affected by the external circuit. This paper proposes a novel generalized associated discrete circuit (G-ADC) model with parameterized history current sources. By utilizing the stability region of the feasible parameter space, the optimized G-ADC models with the best damping characteristic are developed for both two-level and three-level converters. The analytical results also guarantee that the parameters of the optimized G-ADC model are independent of the external circuit for most power grid applications. Furthermore, an field programmable gate array (FPGA)-based real-time simulation platform is built to verify the feasibility of the proposed scheme. Extensive simulation and hardware-in-loop experiment results demonstrate the effectiveness and superiority of best-damped models as well as the modeling flexibility corresponding to insensitivity to operating conditions and external system parameters.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • On Exploiting Active Redundancy of a Modular Multilevel Converter to
           Balance Reliability and Operational Flexibility
    • Authors: Jaesik Kang;Heejin Kim;Hong-Ju Jung;Dong-Su Lee;Chan-Ki Kim;H. Alan Mantooth;Kyeon Hur;
      Pages: 2234 - 2243
      Abstract: This paper presents a practical strategy for utilizing the submodule (SM) redundancy of a modular multilevel converter (MMC) for its fault tolerance. This strategy provides a systematic framework for balancing the tradeoff between two conventional methods for using the active redundancy and, thus, achieves operational flexibility. One of the existing methods improves SM reliability owing to less voltage stress on the SM components by employing all of the SMs to form the ac or dc voltages (voltage-sharing mode). The other avoids transients by keeping the average SM voltage constant at the cost of slightly increased stress on the SM components (fixed-level mode), which, however, can be controlled to provide the grid-adaptive operation by reserving the energy of the SMs not in service. We, thus, develop a new redundancy management scheme by integrating these two methods and exploiting their technical benefits to meet the PQ requirements and MMC control performance. This research provides a theoretical basis and a technical guide to determining the number of SMs, which can further increase the voltage steps as per the MMC and grid conditions. This paper also connects the remaining PQ capability of the MMC at a particular operating point with the SM redundancy concept by defining a potential redundancy, especially useful when the physical redundancy is exhausted. The theoretical findings and efficacy of the proposed strategy are validated through PSCAD/EMTDC time-domain simulations followed by experiments using a nine-level single-phase MMC system.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Transformer-Isolated Common-Mode Active EMI Filter Without Additional
           Components on Power Lines
    • Authors: Sangyeong Jeong;Dongil Shin;Jingook Kim;
      Pages: 2244 - 2257
      Abstract: This paper proposes a new structure of transformer-isolated active EMI filter (AEF) without additional components on power lines for the reduction of common-mode (CM) conducted emissions (CE). The noise attenuation performance and loop gain are rigorously analyzed, and the design guides for the proposed AEF are developed. The AEF is designed in a compact package for the application to a switching mode power supply. The performance, stability, and leakage currents of the AEF are experimentally validated by various measurements. The CM EMI filter, including the AEF, achieves the additional CE reduction by 10 to 20 dB at a frequency range lower than 1 MHz. Also, the noise peaks due to the resonances at several MHz are reduced by 7 dB. The weak points of the conventional CM EMI filter at both low and high frequencies are effectively improved by employing the proposed AEF.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Active Cross-Correlation Anti-Islanding Scheme for PV Module-Integrated
           Converters in the Prospect of High Penetration Levels and Weak Grid
           Conditions
    • Authors: Dionisis Voglitsis;Nick Peter Papanikolaou;Anastasios Ch. Kyritsis;
      Pages: 2258 - 2274
      Abstract: This paper introduces a new cross-correlation anti-islanding detection scheme for module-integrated converters (MICs) with pseudo dc-link. The proposed scheme periodically injects a second-order harmonic current component of low magnitude (in open-loop mode) and evaluates grid response by means of correlation. The proposed scheme is highly reliable, providing nondetection-zone free operation, fast detection, and compliance with the relevant power quality and anti-islanding standards. Additionally, it excels in lower computational cost, reduced fault detection zone, and higher output power quality, compared to the referenced anti-islanding schemes that are compatible with MICs. Last but not least, it can be implemented in MIC platforms without requiring an output current sensor, being an easily upgradable solution in software level. A firm theoretical framework that considers both high penetration levels of PV systems and weak grid conditions is also included in this paper. The theoretical framework, as well as the effectiveness of the proposed scheme, is verified through extensive experimental results for various electrical-network parameters and nonlinear loading conditions. Finally, a comprehensive comparison between the proposed method and the most common anti-islanding techniques (compatible with MICs) is performed, leading to some valuable conclusions from MICs perspective.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Maximum Power Loading Factor (MPLF) Control Strategy for Distributed
           Secondary Frequency Regulation of Islanded Microgrid
    • Authors: Zhikang Shuai;Wen Huang;Xia Shen;Yifeng Li;Xin Zhang;Z. John Shen;
      Pages: 2275 - 2291
      Abstract: Microgrids rely on both primary and secondary frequency control techniques to maintain system stability. Secondary frequency control effectively minimizes frequency fluctuations by adjusting the active power reference in each power inverter, but requires complex and costly interequipment communication. In this paper, we propose a distributed secondary frequency control strategy for microgrids containing multiple virtual synchronous generator (VSG) units based on a new maximum power loading factor (MPLF) concept. The MPLF algorithm facilitates power sharing by dynamically identifying the maximum VSG loading factor at each time instance, and then using this value as a unified reference signal for all the VSGs in the microgrid. The active power reference for each VSG will be adjusted based on the unified reference signal, subsequently the secondary frequency control can be realized. The proposed strategy does not require high-bandwidth communication since the MPLF data are transmitted among the VSGs using low-bandwidth communication. We also develop small-signal models for the control architecture to analyze the influence of major proportional–integral control parameters and communication latency. The MPLF control strategy is implemented using custom digital signal processor controllers, and experimentally validated using hardware in loop simulations. Finally, the new control paradigm demonstrates significant tolerance for communication delay or failure, which we purposely introduced in our investigation.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Effects of the Hybrid Composition of Commercial Lithium-Ion Capacitors on
           Their Floating Aging
    • Authors: Nagham El Ghossein;Ali Sari;Pascal Venet;
      Pages: 2292 - 2299
      Abstract: Lifetime of energy storage systems is a key factor that is extremely influenced by the operating conditions. For this reason, lithium-ion batteries (LiBs) and supercapacitors (SCs) were subjected to accelerated aging tests in several previous research in order analyze their lifespan. Lithium-ion capacitors (LiCs), which fall in between LiBs and SCs, are still considered as a novel technology. Their behavior during accelerated aging tests is not yet well studied in the literature. This paper focuses on studying the degradation of their properties during floating aging. Eighteen samples were tested under three different voltage values and two different temperatures over 12 months. Cells that were discharged to the minimum voltage showed a severe capacitance decrease that was much higher than the one of fully charged cells. The best storage voltage of LiCs was found to be 3 V, which is equivalent to a half charging state. The hybrid structure of LiCs was found to be the major cause of this change in behavior during aging at different voltages. Mechanisms that affect the electrodes and the internal composition of the cells in the diverse conditions were analyzed and predicted.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Finite-Set Model Predictive Power Control of Brushless Doubly Fed Twin
           Stator Induction Generator
    • Authors: Xinchi Wei;Ming Cheng;Jianguo Zhu;Haitao Yang;Rensong Luo;
      Pages: 2300 - 2311
      Abstract: This paper presents a finite-set model predictive power control (FS-MPPC) method for the brushless doubly fed twin stator induction generator (BDFTSIG) in variable speed constant frequency generation applications. The FS-MPPC controller is developed in a general reference frame from which all other reference frames can be deduced readily. The invariant feature of the predictive power model in various reference frames contributes to the reference frame-free characteristic of the developed FS-MPPC controller, enabling its application more flexible and universal. Besides, the arduous process of control winding flux estimation is avoided in the FS-MPPC controller by choosing state variables that are easy to be obtained. Moreover, the influence of rotor circuit that has long been neglected in the existing controllers for the brushless doubly fed induction machines is embedded within the predictive power model and inherently considered in the FS-MPPC controller, which contributes to accurate power control of the BDFTSIG. Furthermore, the feasibility and effectiveness of the developed FS-MPPC controller regarding different power levels and grid fault conditions are briefly discussed. Finally, numerical simulations and experimental tests are carried out, which demonstrates the effectiveness of the developed FS-MPPC controller.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Single-Stage Soft-Switching High-Frequency AC-Link PV Inverter: Design,
           Analysis, and Evaluation of Si-Based and SiC-Based Prototypes
    • Authors: Masih Khodabandeh;Ehsan Afshari;Mahshid Amirabadi;
      Pages: 2312 - 2326
      Abstract: This paper proposes a high-power-density and reliable inverter topology, which transfers the maximum power of a PV array to the load in one power conversion stage. The single-stage power conversion, along with the soft-switching capability of the proposed three-phase PV inverter promises high efficiency at all operating points. Instead of a capacitive dc link that decouples the dc–dc converter and the voltage source inverter in traditional two-stage PV inverters, a high-frequency capacitive ac link is employed in the proposed inverter, which enables exploiting a very small film capacitor, rather than a bulky electrolytic capacitor, for transferring power. Eliminating electrolytic capacitors prolongs the lifetime of this inverter. Considering the long lifetime of PV modules, this feature is of high importance in PV applications. The high-frequency ac link also allows using high-frequency transformers for providing galvanic isolation. Therefore, this inverter is expected to have a very high power density. This paper presents principles of the operation and control, design, and analysis of this inverter, and verifies the performance of the inverter through two prototypes: a 2-kW Si-based prototype and a 2-kW SiC-based prototype operating at different switching frequencies.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Grid Identification and Adaptive Voltage Control in a Smart
           Transformer-Fed Grid
    • Authors: Zhi-Xiang Zou;Giampaolo Buticchi;Marco Liserre;
      Pages: 2327 - 2338
      Abstract: The interaction of the smart transformer (ST) with the grid-converter-based distributed energy resources (DERs) could trigger instability. Recent research efforts have been made to study the stability issues of the DERs in an ST-fed grid and the corresponding stabilization methods. Differently from the previous investigation focused on the DERs’ stability, this paper studies the impacts of the increasing penetration of grid-converter-based devices on the ST low voltage side converter, in particular the stability margin degradation in the low-frequency range. To improve the stability margin, a lead element filter (LEF)-based voltage control offers a simple and flexible solution, which is able to alleviate resonance and achieve phase compensation. Considering the variation of grid characteristics, the resonant frequency is online identified and used for the parameter tuning of LEF. Moreover, the grid characteristics in frequency domain can be thereby estimated using the vector fitting method based on the frequency sweeping data. The robustness and sensitivity analysis are carried out, showing that the proposed voltage control is insensitive to the changes of system parameters of local grid converters. Simulation and experimental results are provided to validate the effectiveness of the proposed control strategy.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Dual-Active-Bridge-Based Novel Single-Stage Low Device Count
           DC–AC Converter
    • Authors: Shiladri Chakraborty;Souvik Chattopadhyay;
      Pages: 2339 - 2354
      Abstract: This paper presents a novel single-stage, isolated, and single-phase dc–ac converter topology, suitable for low-medium power-scale solar photovoltaic and fuel-cell applications. The circuit employs two full-bridge cells with floating dc bus capacitors placed on either side of a high-frequency transformer and works on the dual-active-bridge principle. It has advantages of a single-stage power processing structure, low device count (uses eight switches), and the possibility of achieving zero-voltage-switching operation over the full ac line cycle. Moreover, by dynamic variation of phase-shift between the high-frequency primary and secondary voltages, twice-line-frequency energy buffering can be affected via the high-voltage side dc bus capacitor, which reduces decoupling capacitance requirement, enabling a film capacitor-based implementation. Basic operating principle, control strategy, and detailed design optimization guidelines of the circuit are described followed by simulation results to validate the approach. Practical evaluation of converter performance is done on a 250 W, 20–35 V input, and 110 V rms output prototype.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Frequency Optimization for Inductive Power Transfer Based on AC Resistance
           Evaluation in Litz-Wire Coil
    • Authors: Jiangtao Liu;Qijun Deng;Dariusz Czarkowski;Marian K. Kazimierczuk;Hong Zhou;Wenshan Hu;
      Pages: 2355 - 2363
      Abstract: A coil with a high quality factor $Q$ is desired to obtain a high efficiency for inductive power transfer (IPT). $Q$ is proportional to the coil inductance and operating frequency, while it is inversely proportional to the coil resistance, which increases with frequency. An optimized frequency exists to achieve the maximum efficiency. Eddy currents and resulting ac resistance in Litz-wire coils are attributed to magnetic field. Especially, the induction component of the ac resistance is approximately proportional to the squared magnetic field to which the coil is exposed to. FEA simulations are conducted and surface integral method is employed to determine the squared field. Additionally, the volume integral method is proposed to evaluate the overall effect of the field on the induction resistance. The optimized frequency for the maximum efficiency is obtained, using the squared field calculation and resulting ac resistance evaluation. Sample prototype coils are manufactured to verify the resistance analysis methods. An IPT system is built employing these coils. Experiments show that the IPT system achieves the highest efficiency at frequencies closed to the predicted optimized ones.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Wide Design Range of Constant Output Current Using Double-Sided LC
           Compensation Circuits for Inductive-Power-Transfer Applications
    • Authors: Xiaohui Qu;Haijun Chu;Zhicong Huang;Siu-Chung Wong;Chi K. Tse;Chunting Chris Mi;Xi Chen;
      Pages: 2364 - 2374
      Abstract: Inductive-power-transfer (IPT) converters should desirably achieve nearly zero reactive circulating power, soft switching of power devices and load-independent constant output voltage or current with optimized transfer efficiency, and lowest component ratings. However, the load-independent output characteristic is dependent on IPT transformer parameters and their compensation. The space-constrained IPT transformer restricts the design of the low-order resonant circuit compensated IPT converter, making the IPT converter hard to optimize. This paper will analyze conditions under which any extra design freedom can be allowed for a double-sided LC compensation circuit in order to achieve load-independent output and zero reactive power input. A detailed analysis is given for the double-sided LC compensation achieving zero reactive power input and constant current output, without being constrained by the transformer parameters. Design conditions of the compensation circuit parameters for achieving these two properties are derived. A complementary LC-CC compensated IPT converter is further proposed to extend the output current amplitude limitation of the double-sided LC compensated IPT converter. Finally, the prototypes of the IPT converters are constructed to verify the design flexibility of the proposed double-sided LC compensation circuit for achieving the multiple objectives.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Extended Topology for a Boost DC–DC Converter
    • Authors: Farzad Mohammadzadeh Shahir;Ebrahim Babaei;Murtaza Farsadi;
      Pages: 2375 - 2384
      Abstract: In this paper, a new structure for a nonisolated boost dc–dc converter is proposed. The proposed converter generates higher voltage gain than some conventional nonisolated boost dc–dc converters. In this paper, the voltage and current equations of the elements and voltage gain in continuous conduction mode and discontinuous conduction mode are extracted. Then, the critical inductance converter is extracted and the current stresses in the switches are calculated. To achieve high voltage gain, a generalized structure based on the proposed structure generates for dc–dc converters. Meanwhile, the root mean square current relations of devices are obtained for an extended structure. Finally, the results of PSCAD/EMTDC software and laboratory prototype are used to reconfirm theoretical concept.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • LCLC Converter With Optimal Capacitor Utilization for
           Hold-Up Mode Operation
    • Authors: Yang Chen;Hongliang Wang;Zhiyuan Hu;Yan-Fei Liu;Xiaodong Liu;Jahangir Afsharian;Zhihua Yang;
      Pages: 2385 - 2396
      Abstract: In data center and telecommunication power supplies, the front-end dc–dc stage is required to operate with a wide input voltage range to provide hold-up time when ac input fails. Conventional LLC converter serving as the dc–dc stage is not suitable for this requirement, as the normal operation efficiency (at 400 V input) will be penalized once the converter is designed to achieve high peak gain (wide input voltage range). This paper examined the operation of the LCLC converter and revealed that the LCLC converter could be essentially equivalent to a set of LLC converters with different magnetizing inductors that are automatically adjusted for different input voltages. In nominal 400 V input operation, the LCLC converter behaves like an LLC converter with large magnetizing inductor, thus the resonant current is small. In the hold-up period, when the input voltage reduces, the equivalent magnetizing inductor will reduce together with switching frequency reducing, thus the converter achieves high peak gain. In this paper, a new design methodology is also proposed to achieve optimal utilization of the two resonant capacitors for high power application. To verify the effectiveness of the LCLC converter for hold-up operation, comprehensive analysis has been conducted; a detailed step by step design example based on capacitor voltage stress is introduced; an experimental LCLC prototype optimized at 400 V, with input voltage range of 250–400 V and 12 V/500 W as output has been presented.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Quadratic Boost DC–DC Converter With High Voltage Gain and Reduced
           Voltage Stresses
    • Authors: Sin-Woo Lee;Hyun-Lark Do;
      Pages: 2397 - 2404
      Abstract: This paper proposes a quadratic boost dc–dc converter with a high voltage gain and reduced voltage stresses. The conventional quadratic boost converter has a limited voltage gain, which is not suitable for high-step-up applications with various microgrids. In the proposed converter, to improve the voltage gain beyond that of a quadratic converter, a coupled inductor is adopted. Additionally, passive clamping circuits are applied to reduce the high voltage stresses caused by leakage inductance of the coupled inductor. Hence, additional power losses from the snubber circuit do not occur, and low-voltage-rating switching devices can be utilized for the main switch and output diode. Moreover, the reverse-recovery problem of the output diode can be alleviated by the leakage inductance. Therefore, the total power efficiency is improved. The theoretical analysis of the proposed converter is verified with a 300-V, 120-W prototype.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • High-Frequency LLC Resonant Converter With Magnetic Shunt Integrated
           Planar Transformer
    • Authors: Mingxiao Li;Ziwei Ouyang;Michael A. E. Andersen;
      Pages: 2405 - 2415
      Abstract: Achieving high efficiency and high power density is emerging as a goal in many power electronics applications. LLC resonant converter has been proved as an excellent candidate to achieve this goal. To achieve smaller size of passive components, the resonant inductor in the LLC converter is usually integrated into the transformer by utilizing its leakage inductance. However, the leakage inductance of the transformer is usually insufficient and thus the LLC converter has to be operated in a limited frequency range (this limits the input voltage range accordingly), otherwise the power efficiency will drop dramatically. Therefore, a larger resonant inductance in the LLC converter is expected to operate in a wider input voltage range. This paper proposes a new method to create a larger resonant inductance by using a magnetic shunt integrated into planar windings. The accurate leakage inductance modeling, calculation, and optimal design guideline for LLC planar transformer, including optimal magnetic shunt selection and winding layout, are presented. A 280–380 V input and output 48 V–100 W half-bridge LLC resonant converter with 1 MHz resonant frequency is built to verify the design methodology. A comparison is made between two converters with the same parameters, one using magnetic shunt integrated transformer and the others using traditional planar transformer and external inductor. Experimental result shows the proposed converter with magnetic shunt is capable to achieve comparable high efficiency and regulation capability with the other under a wide input voltage, which verifies the optimal design methodology. Above all, this magnetics integration methodology reduces the whole converter's volume and thus increases the power density.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Variable on-Time Control Scheme for the Secondary-Side Controlled
           Flyback Converter
    • Authors: Alexander Connaughton;Arash Pake Talei;Kennith Kin Leong;Klaus Krischan;Annette Muetze;
      Pages: 2416 - 2426
      Abstract: This paper presents an analysis of a novel control approach for the secondary side controlled flyback concept, along with improved drain–source voltage sensing for more precise gate signals and reduced losses. In contrast to the existing control scheme for this concept, the approach presented here sustains constant switching frequency throughout the load range without any additional hardware, boosting efficiency and simplifying coupled inductor design optimization. A 65-W demonstrator shows minimal output ripple during load changes, peak efficiency of 89.90%, natural output current limiting in overload conditions, and utilizes a novel lossless synchronous-rectification sensing subcircuit with minimal zero current crossing delay.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Switching Delay in Self-Powered Nonlinear Piezoelectric Vibration Energy
           Harvesting Circuit: Mechanisms, Effects, and Solutions
    • Authors: Zhongsheng Chen;Jing He;Jianhua Liu;Yeping Xiong;
      Pages: 2427 - 2440
      Abstract: Piezoelectric vibration energy harvesting (PVEH) has been proved to be much promising in making low power electronics completely self-powered due to wide availability and high energy density. Self-powered synchronized switching harvesting on an inductor (SSHI) circuits have been proved to greatly increase the performance of a PVEH device and peak detector-based self-powered switches are widely used. In practice, however, the switch is impossible to turn on simultaneously at peak displacements due to nonlinear components so that switching delay (SD) always exists. Furthermore, the SD will degrade the performance of PVEH devices, so it must be reduced. Therefore, for this kind of SSHI circuits, the purpose of this paper is to explore basic causes of generating SD and investigate the corresponding solution. First, theoretical model of SD in self-powered parallel SSHI (SP-PSSHI) is derived and the SD is first proved to be positive. Then, effects of key component parameters on the SD are studied. Based on above results, an improved SP-PSSHI (ISP-PSSHI) circuit is proposed by adding a voltage divider and its SD is proved to be less than that of the SP-PSSHI circuit. Next, the key factor is discussed, namely the divider resistor. Circuit simulations validate theoretical results and also expose that there are optimal resistor and capacitor of the envelope detector for achieving the maximum harvested power. In the end, experimental results show that the ISP-PSSHI circuit can improve the averaged harvested power about 11% more than that of the SP-PSSHI circuit under choosing optimal components.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • MagCap DC–DC Converter Utilizing GaN Devices: Design Consideration and
           Quasi-Resonant Operation
    • Authors: Jong-Won Shin;Masanori Ishigaki;Ercan M. Dede;Jae Seung Lee;
      Pages: 2441 - 2453
      Abstract: A MagCap DC–DC converter using GaN semiconductor devices is presented to improve the efficiency and modularity of the vehicular power system. While the topology is as simple as the flyback converter, all the semiconductor switches turn on and off with soft switching. A design guideline to transformer and capacitor is suggested considering the conduction loss and voltage stress of the switches. A quasi-resonant (QR) operation for low output-power condition is also explained. The switches turn on at the valley of the drain-source waveform to secure soft switching and maximize the efficiency. A 180-W prototype hardware was populated on 63 mm × 31 mm printed circuit board using 200-V GaN FET devices. Peak efficiency was 97.1% at 155-W output power and 1.2-MHz switching frequency. Another prototype was built for the QR operation and demonstrated 91.6% peak efficiency by maintaining the soft switching and avoiding excessive switching frequency.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Multitrack Power Factor Correction Architecture
    • Authors: Minjie Chen;Sombuddha Chakraborty;David J. Perreault;
      Pages: 2454 - 2466
      Abstract: Single-phase universal-input ac–dc converters are needed in a wide range of applications. This paper presents a novel power factor correction (PFC) architecture that can achieve high-power density and high efficiency for grid-interface power electronics. The multitrack PFC architecture reduces the internal device voltage stress of the power converter subsystems, allowing PFC circuits to maintain zero-voltage-switching at high frequency (1 MHz–4 MHz) across universal input voltage range (85 $rm V_{text{ac}}$–265 $rm V_{text{ac}}$). The high performance of the power converter is enabled by delivering power in multiple stacked voltage domains and reconfiguring the power processing paths depending on the input voltage. This multitrack concept can be used together with many other design techniques for PFC systems to create mutual advantages in many function blocks. A prototype 150 W, universal ac input, 12 $rm V_{text{dc}}$ output, isolated multitrack PFC system with a power density of 50 W/in$^3$, and a peak end-to-end efficiency of 92% has been built and tested to verify the effectiveness of the multitrack PFC architecture.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • An Improved Fundamental Harmonic Approximation to Describe Filter Inductor
           
    • Authors: Yiming Chen;Jianping Xu;Jin Sha;Leiming Lin;Jing Cao;
      Pages: 2467 - 2478
      Abstract: The influence of a filter inductor on the steady-state performance of a parallel-type resonant converter is elaborated and analyzed in this paper. By steady-state operation analysis, it is shown that the ripple current of the filter inductor results in an inaccurate prediction of fundamental harmonic approximation (FHA), and such problem would become serious when the filter inductance is small. In order to portray such feature, an improved fundamental harmonic approximation (IFHA) is proposed. Unlike an FHA equivalent circuit, an equivalent inductor is added to the ac resistance parallelly in an IFHA equivalent circuit. Due to that, the equivalent inductor branch takes account of the ripple current of the filter inductor, and the IFHA is expected to own higher accuracy and can be used in a parameter design procedure. In this paper, the equivalent inductor expressions of full-bridge rectifier and current-doubler rectifier are derived as examples. In order to verify the theoretical analysis, a 500 W LCC resonant converter is built as a prototype. The close-loop experiment results show that small filter inductance would lead to the failure of output voltage regulation and hard-switching operation of power switches. And open-loop experiment results show the IFHA gives more accurate predictions than those of FHA.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Topology-Reconfigurable Fault-Tolerant LLC Converter With High Reliability
           and Low Cost for More Electric Aircraft
    • Authors: Guipeng Chen;Luan Chen;Yan Deng;Kun Wang;Xinlin Qing;
      Pages: 2479 - 2493
      Abstract: Thanks to the advantages of high fuel efficiency and low emission, more electric aircraft (MEA) has attracted increasing attention in recent years. For MEA, high reliable power converters which can keep working after multiple unexpected faults, are highly desired in the electrical power system to guarantee safety. In order to fulfill the high reliability requirements, a novel fault-tolerant LLC converter is proposed for MEA in this paper, which can keep working after two ideal shorted-circuit faults occurred on switches with a redundant circuit and topology reconfiguration. The redundant circuit is employed to achieve the first fault-tolerant ability, and when the second switch failure occurs, the proposed converter would be auto-reconstructed with the aid of two additional diodes to ensure uninterrupted operation. Because only two extra diodes are added to achieve the second fault-tolerance, the system reliability is significantly enhanced with low additional cost. Moreover, both the voltage/current stresses and the small-signal models of proposed converter are approximate in all prefault and postfault modes, contributing to simplified circuit design and reliable control system. Finally, a 500 W prototype is designed and built to experimentally verify the advantages of proposed fault-tolerant LLC converter.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Fast-Switching Integrated Full-Bridge Power Module Based on GaN eHEMT
           Devices
    • Authors: Asger Bjørn Jørgensen;Szymon Bęczkowski;Christian Uhrenfeldt;Niels Høgholt Petersen;Søren Jørgensen;Stig Munk-Nielsen;
      Pages: 2494 - 2504
      Abstract: New packaging solutions and power module structures are required to fully utilize the benefits of emerging commercially available wide bandgap semiconductor devices. Conventional packaging solutions for power levels of a few kilowatt are bulky, meaning important gate driver and measurement circuitry are not properly integrated. This paper presents a fast-switching integrated power module based on gallium nitride enhancement-mode high-electron-mobility transistors, which is easier to manufacture compared with other hybrid structures. The structure of the proposed power module is presented, and the design of its gate driver circuit and board layout structure is discussed. The thermal characteristics of the designed power module are evaluated using COMSOL Multiphysics. An ANSYS Q3D Extractor is used to extract the parasitics of the designed power module, and is included in simulation models of various complexities. The simulation model includes the SPICE model of the gallium nitride devices, and parasitics of components are included by experimentally characterizing them up to 2 GHz. Finally, the designed power module is tested experimentally, and its switching characteristics cohere with the results of the simulation model. The experimental results show a maximum achieved switching transient of 64 V/ns and verify the power loop inductance of 2.65 nH.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Instantaneous Balancing of Neutral-Point Voltages for Stacked DC-Link
           Capacitors of a Multilevel Inverter for Dual-Inverter-Fed Induction Motor
           Drives
    • Authors: Apurv Kumar Yadav;K. Gopakumar;Krishna Raj R;Loganathan Umanand;Kouki Matsuse;Hisao Kubota;
      Pages: 2505 - 2514
      Abstract: This paper proposes a novel method for instantaneous balancing of neutral-point (NP) voltages with stacked multilevel inverters (MLIs) for variable-speed drives. The stacked MLI uses series-connected dc sources and NPs (connecting points of dc sources) to obtain the desired levels. The balancing of NP voltages are obtained by using a low-voltage-capacitor-fed cascaded H-bridge (CHB) per phase of a symmetrical six-phase induction machine (IM), which ensures zero current drawn from NPs (at any given instant). Since no current is drawn from NPs, the single dc-link operation with stacked capacitors is also possible. The scheme is suitable for applications, where low-voltage dc sources and batteries are stacked to form a dc link. A variable-speed operation is done using a seven-level inverter scheme for a symmetrical six-phase IM, which is formed by three dc-link stacked capacitors cascaded with two low-voltage-capacitor-fed CHBs per phase. Furthermore, the method is extended for an open-end IM to obtain a seven-level common-mode eliminated space vector structure using a single dc link. The generalization of this method for any stacked $n$-level inverter without NP voltage deviation is also presented in this paper. The experimental results and analysis are included to validate the proposed method.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • PWM Frequency Noise Cancellation in Two-Segment Three-Phase Motor Using
           Parallel Interleaved Inverters
    • Authors: Yingliang Huang;Yongxiang Xu;Wentao Zhang;Jibin Zou;
      Pages: 2515 - 2525
      Abstract: This paper proposed a novel method for two-segment three-phase motor to eliminate the harmonics nearby pulsewidth modulation (PWM) frequency. Due to PWM technique and switching losses considerations, ear-piercing high-frequency electromagnetic noise in drive system is common. By using magnetically coupled inductors (MCIs) and interleaved technique, the proposed novel method is able to remove the high-frequency harmonics located nearby the PWM frequency and other odd multiples in two-segment three-phase motor. With this method, the unpleasant acoustic noise could be removed when the PWM frequency is selected near 10 kHz. The size of MCIs mainly depends on the PWM frequency harmonic currents rather than the fundamental frequency currents. Thus, its size is very small compared with LC filter. Moreover, this method remains the control dynamics of two-segment three-phase motor without additional inductance for fundamental-frequency currents. The shift phase of two inverters PWM carriers is π, which is simple to implement. Finally, the effectiveness of the proposed method is verified by experimental results.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Sliding Mode Based Combined Speed and Direct Thrust Force Control of
           Linear Permanent Magnet Synchronous Motors With First-Order Plus Integral
           Sliding Condition
    • Authors: Muhammad Ali Masood Cheema;John Edward Fletcher;Mohammad Farshadnia;Muhammad Faz Rahman;
      Pages: 2526 - 2538
      Abstract: A combined speed and direct thrust force control scheme in the synchronously rotating stator flux oriented reference frame based on sliding mode control is proposed for a linear permanent magnet synchronous motor. First-order stator flux dynamics and a second-order nonlinear state-space model for the combined dynamics of speed and thrust force as system states are presented for the linear machine. These dynamic models are then utilized for synthesis of the two sliding mode control laws for flux regulation and combined speed and thrust force control. The sliding mode control laws produce the orthogonal components of command voltage in the stator flux reference frame which are then applied to the machine by a space vector pulsewidth modulated inverter. Importantly, integral action is also directly included in the control laws by using a modified first-order plus integral sliding condition. The integral action eliminates the steady-state error and provides additional restoring effort in the stator flux and speed tracking combined with thrust force control. Lyapunov stability analysis proves the global asymptotic stability of the proposed control scheme. The effectiveness of the proposed method is validated by extensive experimentation on a prototype linear machine. Practical results demonstrate excellent transient and steady-state speed control performance of the proposed scheme when compared to the state-of-the-art methods.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Coreless Transmitting Coils With Conductive Magnetic Shield for Wide-Range
           Ubiquitous IPT
    • Authors: Byeong G. Choi;Yeong-Hoon Sohn;Eun S. Lee;Seung H. Han;Hoi R. Kim;Chun T. Rim;
      Pages: 2539 - 2552
      Abstract: New coreless transmitting (Tx) coils with a conductive material plate for wide-range ubiquitous inductive power transfer (IPT) zones, i.e., U-IPT zones, where electric devices can be wirelessly charged during operation, are proposed in this paper. Because commercialized IPT systems are only available for short distances of several centimeters and one-to-one charging, the demand is increasing for U-IPT zones in which long-distance wireless charging with three-dimensional (3-D) free-positioning and simultaneous charging of multiple receiving (Rx) coils can be achieved. To satisfy this demand, U-IPT zones should be constructed to have a uniform magnetic field distribution in a wide space, which also poses no risk to the human body. In addition, to generate a uniform magnetic field in a wide 3-D space, such as a single room, the system requires the installation of many Tx coils above the ceilings and behind the walls of the room, and these coils should be capable of high electrical performance to support the efficiency of the entire IPT system and should be of excellent mechanical quality. Therefore, a U-IPT zone should meet the following four criteria: human safety, free-positioning of Rx coils, magnetic field uniformity, and economization. By virtue of a conductive material plate that cancels out the undesired direction of magnetic flux generated from the return wires, the proposed coreless Tx coil does not need any heavy ferromagnetic cores, which can cause nonuniformity of the magnetic field distribution and difficult construction. A prototype coreless Tx coil with the dimensions of 1 m × 1 m × 10 cm was fabricated and experimentally verified for a 1 m × 1 m U-IPT zone. The experimental results showed that 74%, 83%, and 76% high magnetic field uniformity could-be achieved for $z_{1}= {{25}}$ cm, 50 cm, and 75 cm, respectively, and a 3-D omnidirectional wireless power delivery was achieved, while the guideline of the International Commission on Non-Ionizing Radiation Protection for human safety was satisfied throughout the entire U-IPT zone. Moreover, the weight of the entire system was only 9 kg, enabling easy installation. In the multiple wireless charging experiments, 47 W of power was consumed in total by load resistors, each of them connected to nine Rx coils, respectively, with 32% power efficiency at $z_{1}= {{20}}$ cm.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Cancelation of Torque Ripples in PMSM via a Novel Minimal Parameter
           Harmonic Flux Estimator
    • Authors: Nezar Yehya Abou Qamar;Constantine J. Hatziadoniu;
      Pages: 2553 - 2562
      Abstract: This paper presents a novel approach for treating the harmonic torque in permanent magnet motors at selected harmonic orders. The method is based on the online estimation of the motor harmonic flux. For this purpose, a novel minimal parameter harmonic flux estimator (MPHFE) is developed. The MPHFE is formulated such that the inductance, resistance, and stator current and its derivative are not necessary for the estimation of the harmonic flux. This was achieved by forcing the harmonic current to zero through the combined action of a field-oriented controller (FOC) and a feedforward controller. Subsequently, the harmonic flux can be obtained directly from the estimated harmonic back EMF without the involvement of other motor parameters. Finally, the estimated flux is used in conjunction with a comprehensive model of the motor harmonic torque to determine the stator current compensation for eliminating the torque harmonic. Experimental results presented from a permanent magnet motor confirm the theoretical claims in this paper as well as demonstrate the effectiveness of the proposed method to reduce the magnitude of the harmonic torque significantly.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Hybrid Modulation Fault-Tolerant Control of Open-End Windings Linear
           Vernier Permanent-Magnet Motor With Floating Capacitor Inverter
    • Authors: Wenxiang Zhao;Peng Zhao;Dezhi Xu;Zhonghua Chen;Jihong Zhu;
      Pages: 2563 - 2572
      Abstract: In this paper, a new hybrid modulation fault-tolerant control of an open-end winding linear vernier permanent-magnet (OEW-LVPM) motor is proposed. By using a floating capacitor inverter, the proposed OEW-LVPM motor drive can continue operation under open-circuit fault condition. The OEW-LVPM motor fed by dual-inverter system consists of two inverters, which are connected to both ends of the motor windings, including a dc power named as main inverter (MI) and a floating capacitor called as capacitor inverter (CI). When one switch is broken in the CI, the CI topology will be restructured to a three-phase four-switch inverter. Then, an improved six-step modulation is investigated in the MI to reduce the switching frequency, while the conventional modulation is applied in the CI. Thus, the MI can provide all the active power, and the CI is only used to supply the reactive power. The proposed fault-tolerant control method is simulated and the experiments with the OEW-LVPM motor drive are also accomplished to verify the feasibility.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Sensorless Control Scheme of IPMSMs Using HF Orthogonal Square-Wave
           Voltage Injection Into a Stationary Reference Frame
    • Authors: Gaolin Wang;Dianxun Xiao;Guoqiang Zhang;Chengrui Li;Xueguang Zhang;Dianguo Xu;
      Pages: 2573 - 2584
      Abstract: This paper proposes a new sensorless control scheme of interior permanent magnet synchronous motors (IPMSMs) using high-frequency (HF) orthogonal square-wave voltage injection into a stationary reference frame (SRF). This method is an improvement on the conventional HF rotating sinusoidal voltage injection into the SRF. First, discrete sequences of the HF currents are applied to establish the whole signal process. Then, a position estimation method without low-pass filters is proposed, and the phase shifts caused by high-pass filters are also reduced. Therefore, the proposed sensorless control method would not be adversely affected by digital filters, which can solve the common drawbacks of the current SRF-based injection methods. Furthermore, the digital delay in drive systems is considered, and its negative influence can be eliminated as well. The sensorless control method is verified by experiments on a 2.2-kW IPMSM drive platform.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Fast Fault Diagnosis Method for Hall Sensors in Brushless DC Motor Drives
    • Authors: Qian Zhang;Ming Feng;
      Pages: 2585 - 2596
      Abstract: Brushless direct current motors with Hall sensors have been widely used in myriad industrial and commercial applications due to their simplicity and low cost. Meanwhile, the fault tolerant control (FTC) of Hall sensor drives has attracted renewed research attention. During FTC, the motor drives need to diagnose the Hall-sensor fault(s) and reconstruct the faulty signal(s). In this context, we propose an innovative fast fault diagnosis (FFD) method for analyzing different fault cases and diagnosing faulty signal(s) in the shortest possible time. Compared with established fault diagnosis methods, the FFD method does not require complicated vector-tracking observers, and it is capable of handling up to two simultaneous faults while greatly improving the diagnostic speed. Our simulation and experimental results verify the effectiveness of the proposed method and demonstrate its advantages over established methods particularly during transient operations. Due to the simplicity of diagnostic algorithm, the proposed FFD method can be readily implemented in conventional drive systems, either through extra coding within existing controllers or as an auxiliary circuit.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Integrated Uncertainty/Disturbance Compensation With Second-Order
           Sliding-Mode Observer for PMLSM-Driven Motion Stage
    • Authors: Rui Yang;Mingyi Wang;Liyi Li;Yiming Zenggu;Jialin Jiang;
      Pages: 2597 - 2607
      Abstract: The permanent magnet linear synchronous machine driven motion stage for the semiconductor manufacturing equipment and machine tools has the basic requirement of high-dynamic response and high position accuracy. However, due to the direct-drive structure, the effect of parameter uncertainty, including the electrical and the mechanical one, and external disturbance will be directly exerted to the stage. In this paper, an integrated compensation scheme of the overall uncertainty and disturbance is proposed based on the second-order sliding-mode observer (SOSMO). First, an extended state model for considering the disturbance dynamics is established for both the electrical and the mechanical subsystems. To obtain high-dynamic current performance, the predictive current control (PCC) is utilized to design the current controller, and the SOSMO is integrated to compensate the main problem of a parameter mismatch for the PCC. Furthermore, the SOSMO is also configured to estimate the force ripple, and then the observation term is applied in parallel to the velocity controller. With this integrated scheme, the disturbance of the motion stage can be simply and effectively compensated. Experiments are demonstrated to show the effectiveness of the integrated method on both the PCC and force ripple suppression.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • MMC-Based SRM Drives With Decentralized Battery Energy Storage System for
           Hybrid Electric Vehicles
    • Authors: Chun Gan;Qingguo Sun;Jianhua Wu;Wubin Kong;Cenwei Shi;Yihua Hu;
      Pages: 2608 - 2621
      Abstract: This paper proposes a modular multilevel converter (MMC) based switched reluctance motor (SRM) drive with decentralized battery energy storage system for hybrid electric vehicle applications. In the proposed drive, a battery cell and a half-bridge converter is connected as a submodule (SM), and multiple SMs are connected together for the MMC. The modular full-bridge converter is employed to drive the motor. Flexible charging and discharging functions for each SM are obtained by controlling switches in SMs. Multiple working modes and functions are achieved. Compared to conventional and existing SRM drives, there are several advantages for the proposed topology. A lower dc-bus voltage can be flexibly achieved by selecting SM operation states, which can dramatically reduce the voltage stress on the switches. Multilevel phase voltage is obtained to improve the torque capability. Battery state-of-charge balance can be achieved by independently controlling each SM. Flexible fault-tolerance ability for battery cells is equipped. The battery can be flexibly charged under both running and standstill conditions. Furthermore, a completely modular structure is achieved by using standard half-bridge modules, which is beneficial for market mass production. Experiments carried out on a three-phase 12/8 SRM confirm the effectiveness of the proposed SRM drive.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Modular Full-Bridge Converter for Three-Phase Switched Reluctance Motors
           With Integrated Fault-Tolerance Capability
    • Authors: Qingguo Sun;Jianhua Wu;Chun Gan;Jifeng Guo;
      Pages: 2622 - 2634
      Abstract: In this paper, a novel modular full-bridge converter is proposed for three-phase switched reluctance motors (SRMs), which provides an advanced fault-tolerance solution for both the open- and short-circuit faults in switching devices. The proposed converter is composed of two standard six-pack switch modules, providing great benefits for industrial massive production due to the modular topology. Under normal conditions, bidirectional current excitation is developed in the proposed converter, where all the switching devices are actively involved, which makes full use of the switches and averages the heat dissipation for the heat sink design. When a switch fault occurs, the fault signature can be extracted by detecting the characteristics of phase currents and operation modes, and effective fault-tolerance strategies are further applied to achieve the fault-tolerance operation accordingly. Under switch open-circuit faults, the faulty phase is adjusted to unidirectional current excitation without degrading the motor performance. Under switch short-circuit faults, the motor can still work steadily with a single six-switch inverter module by easily reconstructing the proposed converter, without losing any phase windings. The simulation and experiments on a three-phase 12/8 SRM are carried out to validate the feasibility of the proposed converter and control techniques.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Leakage Flux Modeling of Medium-Voltage Phase-Shift Transformers for
           System-Level Simulations
    • Authors: Min Luo;Drazen Dujic;Jost Allmeling;
      Pages: 2635 - 2654
      Abstract: Cascaded H-Bridge converters in medium-voltage (MV) applications have all the dc link capacitors supplied from external source through a multiwinding phase-shift transformer. This type of transformers has a complex winding geometry, which leads to unbalanced leakage flux paths. The unbalance affects the dynamic behavior of the converters. This work proposes a modeling approach, which realistically captures the unbalance in the leakage flux path of phase-shift transformers, using permeance magnetic circuit. The model can be seamlessly integrated into system-level simulation of power electronic circuits. Taking advantage of the repetitive structure of the windings, the model requires very limited number of parameters, which can be easily obtained from the geometry data together with only a few experimental tests. The fidelity of the model is experimentally confirmed on a phase-shift transformer from a commercial MV drive system.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Energy Losses in Soft Magnetic Materials Under Symmetric and Asymmetric
           Induction Waveforms
    • Authors: Hanyu Zhao;Carlo Ragusa;Carlo Appino;Olivier de la Barrière;Youhua Wang;Fausto Fiorillo;
      Pages: 2655 - 2665
      Abstract: Magnetic losses under triangular symmetric and asymmetric induction waveforms have been measured over a broad range of frequencies and predicted starting from standard results obtained with sinusoidal induction. Nonoriented Fe-Si and Fe-Co sheets, nanocrystalline Finemet–type ribbons, and Mn-Zn ferrites have been investigated up to f = 1 MHz and duty cycles ranging between 0.5 and 0.1. The intrinsic shortcomings of the popular approach to loss calculation of inductive components in power electronics, based on the empirical Steinmetz equation and its numerous modified versions, are overcome by generalized application of the statistical theory of losses and the related concept of loss separation. While showing that this concept applies both to ferrites and metallic alloys and extracting the hysteresis (quasi-static), excess, and classical loss components, we relate in a simple way the magnetic energy losses under symmetric triangular induction (square wave voltage) and sinusoidal induction. The loss behavior under asymmetric triangular induction is retrieved from the symmetric one, by averaging the energy losses pertaining to the two different semiperiods. Good comparison with the experimentally measured energy loss versus frequency behavior is demonstrated in all materials.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Differential-Mode and Common-Mode Coupled Inductors for Parallel
           Three-Phase AC–DC Converters
    • Authors: Sungjae Ohn;Xuning Zhang;Rolando Burgos;Dushan Boroyevich;
      Pages: 2666 - 2679
      Abstract: In this paper, an integrated structure of coupled inductors is proposed for three-phase ac–dc power conversion. According to the differential-mode and common-mode, three coupled inductors are integrated into two inductors; one for suppressing only differential-mode circulating current, the other only for common-mode circulating current. With a series connection, two proposed inductors can be designed to replace the three coupled inductors with an identical impedance and smaller size. The proposed inductors can easily be built with standard shape cores which gives a large advantage on design for manufacturability. Analytic solutions of the maximum magnetic flux for the proposed inductors are derived for space vector PWM (SVPWM) and discontinuous PWM (DPWM)60° to estimate possible size-reduction in flux-limited designs. The solutions show that maximum volt-seconds is reduced by 33% for whole modulation index range in the DPWM60° case and a high modulation index range for the SVPWM case. A simple design guideline to replace the conventional coupled inductors is provided. The validity of the proposed integration is verified by circuit simulation and finite element analysis. A prototype design shows that the total weight and volume of the coupled inductors could be reduced by 20%. The proposed integration has been verified by an experiment with 1 kW paralleled three-phase converters.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Novel AC Power Loss Model for Ferrite Power Inductors
    • Authors: Kateryna Stoyka;Giulia Di Capua;Nicola Femia;
      Pages: 2680 - 2692
      Abstract: Recent studies have proved that sustainable saturation operation of Ferrite Power Inductors (FPIs) allows reducing the inductor size and increasing the power density in Switch-Mode Power Supply (SMPS) applications. This paper discusses a new behavioral model for reliable prediction of ac power loss in FPIs, including the effects of saturation. The new model has been identified by means of the Genetic Programming (GP) algorithm combined with a Multi-Objective Optimization (MOO) technique, starting from large sets of power loss experimental measurements. The proposed ac power loss model uses as input variables the voltage and switching frequency imposed to the inductor by the SMPS operation, while the dc inductor current is used as a parameter expressing the impact of saturation. Such quantities can be easily determined for whatever converter topology and in real-world switching operation, thus confirming the readiness and the easiness-to-use of the proposed behavioral model. The results of experimental tests presented in this paper prove the reliability of the power loss predictions, also by correctly accounting for the impact of inductors saturation.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Series Resonant Converter-Based Multichannel LED Driver With Inherent
           Current Balancing and Dimming Capability
    • Authors: Taha Nurettin Gücin;Bekir Fincan;Muhammet Biberoğlu;
      Pages: 2693 - 2703
      Abstract: This study proposes a high-efficiency light-emitting-diode (LED) driver based on the series resonant converter (SRC) topology. As the major requirement from LED driver circuits is the ability of providing constant current for maintaining a certain luminescence level, it is utilized that the SRC operates as a frequency-controlled constant current source when the switching frequency is lower than half of the resonance frequency. This approach ensures a reliable and dimmable constant current power supply that can operate in an open-loop configuration. A design procedure for the proposed multichannel LED driver is given and experimental results for a prototype that is capable of delivering 50 V–0.35 A output for six channels are presented. It is also shown that the proposed driver is capable of ensuring high efficiency values (92%–93.5%) for a wide output power (14–58 W).
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Battery Operated Soft Switching Resonant Buck–Boost LED Driver With
           Single Magnetic Element
    • Authors: Farhad Pouladi;Hosein Farzanehfard;Ehsan Adib;
      Pages: 2704 - 2711
      Abstract: A simple buck–boost LED driver suitable for battery operated applications with limited input voltage level is presented in this paper. Soft switching performance is provided for the main switch via a resonant circuit to improve the converter efficiency. The incorporated auxiliary switch also performs under zero voltage switching condition. Both power switches can be driven with a simple gate drive circuit, so, the additional switch does not add any driving complexity. In addition, only one magnetic element is utilized in the proposed LED driver which contributes to circuit simplicity and lower weight and size. Also, all diodes turn off at zero current switching which eliminates the reverse recovery losses and improves efficiency. A laboratory prototype converting 12 V input voltage to 32 V output operating at 26 W output power is implemented and tested to verify the effectiveness of the proposed LED driver.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Bridgeless Electrolytic Capacitor-Free LED Driver Based on Series
           Resonant Converter With Constant Frequency Control
    • Authors: Junfeng Liu;Hanlei Tian;Guozhuang Liang;Jun Zeng;
      Pages: 2712 - 2725
      Abstract: High-brightness light-emitting diode (LED) is next generation of green lighting. However, the bulky electrolytic capacitor is required to compensate the difference of pulsating power, thereby restricting the lifetime. Meanwhile, the existing drivers based on pulse frequency modulation (PFM) is bound to arouse heavy electromagnetic interference. In this paper, the series resonant converter based LED drive is proposed to overcome the shortcomings of electrolytic capacitor and PFM control. The proposed method is to attenuate the low frequency ripples delivered from the power factor correction (PFC) to LEDs; therefore, the capacitance is reduced for energy storage of offline LED drivers. On account of the adoption of the switching controlled capacitor (SCC), the constant frequency control is achieved by the regulations of the equivalent capacitance. Half-bridge switches are shared by the bridgeless PFC and the resonant unit, therefore, single-stage LED drive is realized with high efficiency. In addition, SCC is simultaneously shared for the upper and lower half-bridge to reduce the cost and improve the power density. Operating principle, design considerations, and performance comparisons are examined in detail. Finally, all the superior performances of proposed LED driver are verified by simulation and experimental prototypes with two-channel LEDs, and rated output power of 80 W.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Improving the Third Quadrant Operation of Superjunction MOSFETs by Using
           the Cascode Configuration
    • Authors: Juan Rodríguez;Diego G. Lamar;Jaume Roig;Alberto Rodríguez;Filip Bauwens;
      Pages: 2726 - 2738
      Abstract: In this paper, the third quadrant behavior of a high-voltage superjunction mosfet (SJ-FET) in cascode configuration (CC) with a low-voltage silicon mosfet is deeply studied by means of an analytical model and experimental data. The third quadrant dynamic behavior of the SJ-CCs is compared to the standalone counterparts by evaluating their reverse recovery time (tRR), reverse recovery peak current (IRRM), and reverse recovery charge (QRR). An analytical model and experimental results show that the SJ-CC avoids or mitigates the activation of the SJ-FET body diode during the third quadrant operation. As a consequence, the SJ-CC strongly improves the widely used figure-of-merit RON·QRR, which considers the on-state resistance of the transistors (RON). In addition, the results obtained using an SJ-CC are similar or better than those achieved by SJ-FETs with enhanced reverse recovery (i.e., irradiated SJ-FETs). This paper also includes a comparison with commercial wide bandgap switches, concluding that the RON·QRR value provided by the SJ-CC is around eight times higher than that provided by a commercial GaN cascode.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • An Adaptable Interface Circuit With Multistage Energy Extraction for
           Low-Power Piezoelectric Energy Harvesting MEMS
    • Authors: Salar Chamanian;Hasan Uluşan;Aziz Koyuncuoğlu;Ali Muhtaroğlu;Haluk Külah;
      Pages: 2739 - 2747
      Abstract: This paper presents a self-powered interface circuit to extract energy from ambient vibrations for powering up microelectronic devices. The circuit interfaces a piezoelectric energy harvesting micro electro-mechanical systems (MEMS) device to scavenge acoustic energy. Synchronous electric charge extraction (SECE) technique is deployed through the implementation of a novel multistage energy extraction (MSEE) circuit in 180 nm HV CMOS technology to harvest and store energy. The circuit is optimized to operate with minimum power losses when input power is limited, and adapts well to operating conditions with higher input power. The highly accurate peak detector was validated for a wide piezoelectric frequency range from 20 Hz to 4 kHz. A charging efficiency of about 84% has been achieved for 4.75 V open-circuit piezoelectric voltage excited at 390 Hz input vibration under nominal input power range of 30–80 μW. Power optimizations enable the circuit to maintain a conversion efficiency of 47% at input power level as low as 3.12 μW. MSEE provides up to 15% efficiency improvement compared to traditional SECE, and maintains power efficiency as high as possible for a wide input power range.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Comprehensive Investigations on Degradations of Dynamic Characteristics
           for SiC Power MOSFETs Under Repetitive Avalanche Shocks
    • Authors: Jiaxing Wei;Siyang Liu;Sheng Li;Jiong Fang;Ting Li;Weifeng Sun;
      Pages: 2748 - 2757
      Abstract: In this work, degradations of dynamic characteristics for silicon carbide (SiC) power metal-oxide-semiconductor field-effect transistors under repetitive avalanche shocks are investigated in details. With the help of Silvaco TCAD simulations, gate capacitance versus gate voltage (Cg–Vg) measurement, and three-terminal charge pumping test, the main damaged position is demonstrated to be the SiC/SiO2 interface along junction FET (JFET) region instead of the body diode where most of the avalanche current passes through. Dominant avalanche degradation mechanism is then confirmed to be the injection of holes into the gate oxide above the JFET region. Since the channel region and the main junction of body diode are not seriously damaged by the avalanche stress, static parameters all remain stable. Meanwhile, due to the injection of holes, the depletion layer beneath the JFET region gets thinner, resulting in the increase of gate-drain capacitance (Cgd) under low drain-source voltage (Vds) bias condition. It further takes responsibilities for the increments in input capacitance (Ciss), output capacitance (Coss), and reverse transfer capacitance (Crss). Moreover, it results in the extension of Miller plateau. Therefore, the increase of gate charge and delay of turn-off time after being stressed by repetitive avalanche shocks are monitored. Moreover, turn-on and turn-off dissipated energies after different unclamped-inductive-switching stress cycles are extracted. They are rarely influenced by the stress for the overlapping areas of voltage and current during switching procedures are relatively stable.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Single-Inductor Dual-Output Converter With the Stacked mosfet Driving
           Technique for Low Quiescent Current and Cross Regulation
    • Authors: Hsin Chen;Chao-Jen Huang;Chun-Chieh Kuo;Li-Chi Lin;Yu-Sheng Ma;Wen-Hau Yang;Ke-Horng Chen;Ying-Hsi Lin;Shian-Ru Lin;Tsung-Yen Tsai;
      Pages: 2758 - 2770
      Abstract: Stacked mosfet structures made of low-voltage devices suffer from degraded transient response or large footprint when a capacitorless or dominant-pole compensated low-dropout (LDO) regulator biases the driver. Due to the self-stabilizing nature, the proposed stacked mosfet driver (SMD) technology effectively drives the power stage and greatly reduces the noise at the switching nodes for low cross regulation (CR) in a single-inductor dual-output (SIDO) converter. In addition, two inherent LDO regulators in SMD technology fully regulate the dual outputs with the advantage of low quiescent current at no-load conditions. The experimental results show that the test chip fabricated under the 0.25-μm process has low CR of 0.015 mV/mA and ultralow quiescent current of 5 μA under no-load conditions.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Short-Circuit Ruggedness and Failure Mechanisms of Si/SiC Hybrid
           Switch
    • Authors: Jun Wang;Xi Jiang;Zongjian Li;Z. John Shen;
      Pages: 2771 - 2780
      Abstract: The hybrid switch (HyS) of a higher-current main Si IGBT and a parallel lower-current auxiliary Silicon Carbide (SiC) mosfet offer an improved cost/performance tradeoff for practical power electronic designs. The purpose of this paper is to investigate the short-circuit (SC) ruggedness, failure mechanisms, and techniques for improvement of the Silicon/SiC HyS. The influence of major limiting factors, including dc bus voltage, gate drive voltage, gate control pattern, case temperature, and SiC mosfet sizing are experimentally studied. Two SC failure mechanisms, the thermal runaway and gate interlayer dielectric breakdown of the SiC mosfet are identified using microscopic failure analysis techniques. An optimum gate control selection is proposed to improve the HyS's SC withstanding time with minimum increase in its power loss.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Difference in Device Temperature Determination Using p-n-Junction Forward
           Voltage and Gate Threshold Voltage
    • Authors: Guang Zeng;Haiyang Cao;Weinan Chen;Josef Lutz;
      Pages: 2781 - 2793
      Abstract: Determination of chip temperature is a key element in the lifetime estimation of power devices. There are several temperature sensitive electrical parameters for this purpose, which allow accurate measuring of the chip temperature on fully packaged devices. Among all these parameters, the forward voltage of a p-n junction is probably the most widely used parameter for temperature determination of a power semiconductor device. In metal-oxide-semiconductor (MOS) gated power semiconductor devices, gate threshold voltage is an alternative parameter with high temperature resolution. In this paper, the p-n-junction forward voltage and the gate threshold voltage of MOS-gated power devices were investigated. The difference between temperature measurements via the two methods was analyzed.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Novel Hybrid Mode Control for a Phase-Shift Full-Bridge Converter
           Featuring High Efficiency Over a Full-Load Range
    • Authors: Li-Chung Shih;Yi-Hua Liu;Huang-Jen Chiu;
      Pages: 2794 - 2804
      Abstract: A novel hybrid mode control technique for a phase-shift full-bridge (PSFB) converter is proposed in this paper. The proposed method can improve power efficiency under both the light-load and heavy-load conditions. The basic concept of the proposed control technique is to decrease the turns ratio to reduce the circulating current, hence resulting in lower circulating losses. However, the output voltage under heavy load may not be stabilized using phase-shift control if smaller turns ratio is utilized. Therefore, the proposed technique employs asymmetrical pulsewidth modulation to achieve higher output voltage. To further improve the efficiency, an adaptive dead-time control method, which determines the dead-time value according to the load level, is also proposed. To validate the correctness and effectiveness of the proposed method, a 480-W PSFB converter is constructed and experiments are carried out accordingly. Comparing with a conventional PSFB converter, the efficiency of the proposed method can be improved up to 3.2%, 1.3%, and 0.6% under light-load, 30% load, and full-load conditions, respectively.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A DSOGI-FLL-Based Dead-Time Elimination PWM for Three-Phase Power
           Converters
    • Authors: Qingzeng Yan;Rende Zhao;Xibo Yuan;Wenzhong Ma;Jinkui He;
      Pages: 2805 - 2818
      Abstract: The dead-time elimination pulsewidth modulation (PWM) enables the drive pulses of the upper and the lower switching devices to alternate according to the current polarity, thus abandoning the dead time and essentially avoiding the dead-time effect in power converters. However, the current zero crossing will be distorted by the current jump generated by the drive-pulse alternation, and the current zero-crossing distortion will be further intensified if errors exist in the detected current polarity. Thanks to the noise-attenuation and frequency-adaptability characteristics of the double second-order generalized integrator frequency-locked loop (DSOGI-FLL), it can obtain accurate current polarities even in harmonic and unbalanced conditions. A DSOGI-FLL-based dead-time elimination PWM is, therefore, proposed in this paper, and several improvements are made to minimize the current zero-crossing distortion. An underlap period is added when alternating the upper and lower drive pulses to smooth the current jump at zero crossing, and a delay compensation term is inserted in the DSOGI-FLL to compensate both the current measurement delay and the control delay. The effectiveness of the proposed DSOGI-FLL-based dead-time elimination PWM has been validated by experiments, respectively, in the unbalanced-current, power-change, and frequency-variation conditions with an RL load, as well as in a grid-connected converter.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Observer-Based Capacitor Current Sensorless Control Applied to a
           Single-Phase Inverter System With Seamless Transfer
    • Authors: Shu-Syuan Huang;Yoshihiro Konishi;Zong-Zhen Yang;Min-Ju Hsieh;
      Pages: 2819 - 2828
      Abstract: In this paper, capacitor current sensorless control by using an observer is applied in a seamless transfer single-phase inverter. The proposed control system is a multiloop control system. The control loop is composed of a capacitor voltage outer control loop and capacitor current inner control loop for stand-alone mode. For on-grid mode, the grid current outer loop controller is combined with the stand-alone control structure to form a simple controller structure for mode switching. The capacitor current feedback signal is calculated using the observer in the discrete-time domain and thus sensors are not required. Use of the proposed observer for the inverter with capacitor current control has many advantages, such as sensorless capacitor current calculation, one-sample-ahead data prediction for sampling delay compensation, and an average capacitor current without ripple components. Verification of the theoretical analysis is presented through simulation and experiment. A 5-kW single-phase inverter prototype combined with a Li-ion battery is set up with a digital controller using a TI TMS320F28377D microcontroller unit to confirm the feasibility of the system.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A New Voltage Balancing Technique for a Three-Stage Modular Smart
           Transformer Interfacing a DC Multibus
    • Authors: Sante Pugliese;Markus Andresen;Rosa A. Mastromauro;Giampaolo Buticchi;Silvio Stasi;Marco Liserre;
      Pages: 2829 - 2840
      Abstract: DC smart grids represent an alternative to traditional ac power distribution systems. The power conversion stage, interfacing the ac and the dc distribution systems, is the enabling technology to manage multiple dc loads and sources. The three-stage smart transformer (ST) is a promising solution, because it includes a dc–dc power conversion stage providing a dc multibus in output. The modular ST architecture supplies several dc outputs, which allow interfacing a dc smart grid with the ac power system. In this paper, the three-stage ST is based on a cascaded H-bridge (CHB) converter for the ac–dc power conversion, whereas dual active bridge (DAB) converters are adopted for the dc–dc power conversion stage. The peculiarity is that the dc voltage balancing is performed by the dc–dc power conversion stage instead of the CHB converter. It is advantageous for dc smart grids applications where the power sharing among the dc sources and loads is often not balanced. The design of the entire control system is based on the detailed small signal model of the ac–dc and dc–dc power conversion stages of the ST. High dynamic performance of the voltage balancing is fulfilled due to the commonly high switching frequency of the DAB converters.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Research on Active Disturbance Rejection Control With Parameter Autotune
           Mechanism for Induction Motors Based on Adaptive Particle Swarm
           Optimization Algorithm With Dynamic Inertia Weight
    • Authors: Chao Du;Zhonggang Yin;Yanping Zhang;Jing Liu;Xiangdong Sun;Yanru Zhong;
      Pages: 2841 - 2855
      Abstract: An active disturbance rejection control (ADRC) of induction motor based on an adaptive particle swarm optimization (APSO) algorithm is proposed in this paper, in order to realize the precise decoupling of induction motor and the disturbance compensation. The novel control method employs APSO as the automatic tune mechanism for ADRC controller. According to the feedback information of induction motor, an optimal solution can be achieved via the optimization mechanism and self-learning ability of APSO, so the reliance of ADRC controller on parameters can be reduced. In order to obtain the better optimization solution more efficient, the aggregation degree and the evolution speed are introduced into the APSO to dynamically modify the inertia weight based on the practical optimization process. Experimental results indicate that the robustness of the proposed optimal design method for ADRC is better than the conventional ADRC when the disturbances occur, and the method is feasible and effective.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Optimized Modulation and Dynamic Control of a Three-Phase Dual Active
           Bridge Converter With Variable Duty Cycles
    • Authors: Jun Huang;Zhuoqiang Li;Ling Shi;Yue Wang;Jinda Zhu;
      Pages: 2856 - 2873
      Abstract: The three-phase dual active bridge (3p-DAB) converter is a promising topology for high power dc–dc conversion due to advantages of bidirectional power flow, inherent soft-switching capability, and reduced filter volume. This paper presents comprehensive analysis of the duty cycle control (DCC) for optimizing the performance of the 3p-DAB. Based on DCC, an optimized modulation strategy is proposed to minimize the conduction losses of the 3p-DAB in the whole load range. The proposed modulation strategy extends the soft-switching range of the 3p-DAB with large voltage variations simultaneously. It is established through loss analysis that the proposed modulation strategy boosts the efficiency of the 3p-DAB, especially at low loads. When the duty cycles change fast as a result of the abruptly changed transmission power, the transformer currents can become unbalanced, leading to the magnetic bias and oscillations in dc currents. This paper further proposes a fast transient current control (FTCC) method for the 3p-DAB with variable duty cycles. The FTCC enables the converter to transfer from one steady state to another within about one-third switching period, hence balancing the transformer currents rapidly and avoiding oscillations in dc currents. Finally, experimental results verify the outstanding performance of the proposed modulation strategy and FTCC method.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Robustness Improvement of FCS-MPTC for Induction Machine Drives Using
           Disturbance Feedforward Compensation Technique
    • Authors: Liming Yan;Manfeng Dou;Zhiguang Hua;Haitao Zhang;Jianwei Yang;
      Pages: 2874 - 2886
      Abstract: Finite control set-model predictive torque control (FCS-MPTC) has a fast dynamic response because this algorithm directly selects the optimal voltage vector by its cost function for induction machine drives fed by voltage source inverter (VSI). However, belonging to open-loop control paradigm, the FCS-MPTC has torque tracking error due to inevitable load disturbance and mismatched model parameters in reality. In traditional FCS-MPTC, the outer loop, i.e., speed loop, adopts a classic proportional integral (PI) controller, abbreviated as PI-MPTC. The lumped disturbance is only suppressed by a PI controller. However, pole placement of the PI controller is usually designed by cut-and-trial, which is difficult to simultaneously achieve optimal dynamic performance and optimal suppression of lumped disturbance. In this paper, the FCS-MPTC with mismatched parameters is first analyzed. Second, the deficiencies of the traditional PI controller are introduced. Third, disturbance feedforward compensation-based-model predictive torque control (DFCB-MPTC) of induction machine is proposed to compensate lumped disturbance and improve the performance of the system. Furthermore, a simplified stator flux observer is proposed, whose gain matrix is independent of rotor speed. Experimental results verify the feasibility of the proposed DFCB-MPTC. Compared with traditional PI-MPTC, the proposed DFCB-MPTC has better dynamic performance, steady performance, and stronger robustness.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • HM/PWM Seamless Control of a Bidirectional Buck–Boost Converter for a
           Photovoltaic Application
    • Authors: Francisco Méndez-Díaz;Beatriz Pico;Enric Vidal-Idiarte;Javier Calvente;Roberto Giral;
      Pages: 2887 - 2899
      Abstract: The versatile buck–boost dc/dc converter is found suitable for a particular photovoltaic application that requires either a voltage step-up or a voltage step-down operation injecting the maximum available current into an intermediate-voltage battery. It is proposed to implement the converter control stage providing seamless changes between the step-up (boost) and step-down (buck) operating modes. Based on the sliding-mode control technique, a hysteretic-modulation-based (HM) controller is designed allowing the tuning of the switching frequency around either of the two possible operating points. The introduction of minor modifications into the HM implementation results in a pulsewidth modulation controller that preserves the seamless changing features between buck and boost working modes while providing a fixed switching frequency. Experimental results demonstrate that both solutions allow the converter input voltage control by showing a perfect tracking of 1-kHz square-type references, similar to those provided by a classical perturb-and-observe (P&O) MPPT algorithm but much faster.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Five-Level Flying Capacitor Multilevel Converter With Integrated
           Auxiliary Power Supply and Start-Up
    • Authors: Andrew Stillwell;Robert Carl Nikolai Pilawa-Podgurski;
      Pages: 2900 - 2913
      Abstract: This paper presents a five-level flying capacitor multilevel (FCML) converter with an integrated auxiliary power converter to supply power to the controller and gate drive circuitry. The auxiliary power converter is sourced from within the FCML converter at a naturally occurring low-voltage node, reducing the voltage rating requirements by 75% and thus the size of the auxiliary converter. The auxiliary load current drawn from the FCML converter induces an imbalance in the flying capacitors, which is detrimental to the capacitor and switch ratings if left unchecked. To compensate for this imbalance, an active-balancing method is proposed that adjusts the phase and duty cycle of the traditional phase-shifted pulsewidth modulated control signals. The active balancing requires only a single capacitor voltage measurement and proportional control with no additional hardware components. A start-up circuit is proposed to power the auxiliary power supply and soft-start the FCML converter. Experimental results have been demonstrated with an experimental prototype resulting in an excellent flying capacitor balancing and FCML start-up.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Investigation on Extending the DC Bus Utilization of a Single-Source
           Five-Level Inverter With Single Capacitor-Fed H-Bridge Per Phase
    • Authors: Teenu Techela Davis;Anubrata Dey;
      Pages: 2914 - 2922
      Abstract: Enhancement of dc bus voltage utilization for a five-level inverter with single dc source and capacitor-fed H-bridge (CHB) units is investigated in this paper. A carrier-based modulation technique is used for boosting the dc bus utilization, which is established by providing detailed mathematical analysis. The five-level inverter used here is realized by cascading a CHB unit to each phase of a three-level neutral point clamped inverter. The increase in dc bus voltage utilization owes to the pole voltage redundancies offered by CHB units. The floating capacitors of H-bridge units are balanced within a quarter fundamental cycle using the switching state redundancies of pole voltage levels. The aforementioned modulation technique allows the inverter to enhance the dc bus utilization from 0.577 $text{V}_{text{dc}}$ to 0.63 $text{V}_{text{dc}}$ under unity power factor. This enhancement is obtained in the linear modulation range without increasing the dc bus voltage, and thus, the inverter can operate without the presence of low-order harmonics in its phase voltages. The strength of this paper lies in its detailed mathematical analysis for finding out the limiting modulation index and power factor condition in the light of floating capacitor voltage balancing issue. Simulation as well as experimental verification of the modulation scheme is carried out on an induction motor drive under various operating conditions. It is shown that this carrier-based modulation technique is suitable for any single source inverter topology with one CHB unit per phase.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Hybrid Three-Level Full-Bridge Isolated Buck–Boost Converter With
           Clamped Inductor for Wider Voltage Range Application
    • Authors: Yan Li;Fang Li;Fang-Wei Zhao;Xiao-Jie You;Kun Zhang;Mei Liang;
      Pages: 2923 - 2937
      Abstract: An isolated buck–boost (IBB) converter with a hybrid three-level full-bridge primary-side circuit is proposed to achieve wider voltage range regulation. The primary-side circuit is composed of a three-level leg and a two-level leg. The output voltage of the primary-side circuit is five level (i.e., $pm V_{{text{in}}}$, $pm V_{{text{in}}}{text{/ 2}}$, and zero), and the secondary-side circuit is a semiactive full-bridge rectifier with two active switches and two diodes. The input voltage of the secondary-side circuit is three level (i.e., $pm V_{{text{o}}}$ and zero). Hence, the operation voltage range can be wider than the normal IBB converter's with three voltage levels in the primary-side circuit and secondary-side circuit. This paper focuses on the control strategy allowing the converter to operate in boundary current mode at heavy load and in discontinuous current mode at light load with smooth mode transition. The soft-switching performance and output characteristics of the proposed converter are presented in detail. Compared with the semi-dual active bridge converter, the voltage range is doubled and the peak current of the clamped inductor is decreased. An 800-W prototype with 100–400-V input voltage and 380-V output voltage is built and tested to verify the feasibility of the proposed control strategy.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Design of Power Decoupling Strategy for Single-Phase Grid-Connected
           Inverter Under Nonideal Power Grid
    • Authors: Kuan-Pin Huang;Yu Wang;Rong-Jong Wai;
      Pages: 2938 - 2955
      Abstract: Because a single-phase inverter has a power coupling between the dc bus and the ac side, the dc bus always requires large electrolytic capacitors for the power decoupling. Although the active power decoupling circuit can restrain the ripple voltage with twice the fundamental frequency on the dc bus and reduce the required capacitance, previous research works mainly focused on the power coupling of an ideal power grid, and just decoupled the ripple power with twice the fundamental frequency. This study analyzes the power coupling in a nonideal power grid, and designs a novel decoupling method for the power with multiharmonic frequency on the dc bus. By modifying the reference values of dc series split-capacitors, the system control structure can be simplified, and the multifrequency-coupled power decoupling can be realized. Moreover, a notch filter is introduced into the dc voltage feedback path for further reducing the influence of the power coupling on the inverter output current quality. The proposed method can achieve the objective of the multifrequency-coupled power decoupling, even under a weak power-grid environment. Finally, numerical simulations and experimental results are provided to verify the effectiveness of the proposed method in comparison with the traditional capacitor decoupling framework and the dual-voltage control decoupling scheme.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • A Wireless Power and Information Simultaneous Transfer Technology Based on
           2FSK Modulation Using the Dual Bands of Series–Parallel Combined
           Resonant Circuit
    • Authors: Jin-Guk Kim;Guo Wei;Man-Ho Kim;Hyok-Su Ryo;Chunbo Zhu;
      Pages: 2956 - 2965
      Abstract: In this paper, a new wireless power and information simultaneous transfer (WPIT) technology based on binary frequency shift keying (2FSK) modulation using the dual bands of a series–parallel combined resonant circuit (SPRC), SPRC-2FSK-WPIT technology, is proposed. Conventional 2FSK-WPIT technologies commonly employ single resonant band, and due to the insufficient utilization of system resonance, they have inherent disadvantages, such as low efficiency and low system quality factor. In the proposed technology, the system employs dual resonant bands of the SPRC and both of the system carriers use the resonant frequencies, and so the disadvantages of the conventional 2FSK-WPIT technology are eliminated. Optimal design of the SPRC-2FSK-WPIT system is conducted. In the optimized system, the two carriers have similar power and information transfer characteristics, and so a high WPIT performance, including stable power transmission, is guaranteed. The proposed technology is validated by experimental results. The experimental prototype shows up to 20 kb/s of communication rate with maintaining the power transfer efficiency over 85% at the distance of 50 mm.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Modeling and Control of Permanent-Magnet Synchronous Generators Under
           Open-Switch Converter Faults
    • Authors: Christoph M. Hackl;Urs Pecha;Korbinian Schechner;
      Pages: 2966 - 2979
      Abstract: The mathematical modeling of open-switch faults in two-level machine-side converters and the fault-tolerant current control of isotropic permanent-magnet synchronous generators are discussed in this paper. The proposed converter model is generic for any open-switch fault and independent of the operation mode of the electrical machine. The proposed fault-tolerant current control system gives improved control performance and reduced torque ripple under open-switch faults by modifying the antiwindup strategy, adapting the space-vector modulation scheme, and by injecting additional reference currents. The theoretical derivations of model and control are validated by comparative simulation and measurement results.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
  • Comments on “Digital Current Control in a Rotating Reference
           Frame—Part I: System Modeling and the Discrete Time-Domain Current
           Controller With Improved Decoupling Capabilities”
    • Authors: Claudio Alberto Busada;Sebastian Gomez Jorge;Jorge A. Solsona;
      Pages: 2980 - 2984
      Abstract: A recent paper by Hoffmann et al. presents a discrete-time model in a rotating $dq$ reference frame of an R-L filter and its current control. The purpose of this note is, first, to show that the discrete model presented in the paper behaves differently to the sampled continuous-time model of the plant, formulated in the stationary $alpha beta$ reference frame; second, to find the proper discretization of the plant in $dq$ coordinates; and third, to verify that there is cross coupling between axes $d$ and $q$ in the closed-loop system if the original model is used, and that this coupling is not present when using the model found in this note. In the note, it is verified that having a precise model of the plant allows us to fulfill the control objective of obtaining the complete decoupling between axes.
      PubDate: March 2019
      Issue No: Vol. 34, No. 3 (2019)
       
 
 
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