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  Subjects -> ELECTRONICS (Total: 187 journals)
Showing 1 - 200 of 277 Journals sorted alphabetically
Acta Electronica Malaysia     Open Access  
Advances in Electrical and Electronic Engineering     Open Access   (Followers: 7)
Advances in Electronics     Open Access   (Followers: 90)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Power Electronics     Open Access   (Followers: 38)
Advancing Microelectronics     Hybrid Journal  
Aerospace and Electronic Systems, IEEE Transactions on     Hybrid Journal   (Followers: 337)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 26)
Annals of Telecommunications     Hybrid Journal   (Followers: 9)
APSIPA Transactions on Signal and Information Processing     Open Access   (Followers: 9)
Archives of Electrical Engineering     Open Access   (Followers: 14)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 30)
Bioelectronics in Medicine     Hybrid Journal  
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 20)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 38)
Biomedical Instrumentation & Technology     Hybrid Journal   (Followers: 6)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 13)
BULLETIN of National Technical University of Ukraine. Series RADIOTECHNIQUE. RADIOAPPARATUS BUILDING     Open Access   (Followers: 1)
Bulletin of the Polish Academy of Sciences : Technical Sciences     Open Access   (Followers: 1)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 47)
China Communications     Full-text available via subscription   (Followers: 9)
Chinese Journal of Electronics     Hybrid Journal  
Circuits and Systems     Open Access   (Followers: 15)
Consumer Electronics Times     Open Access   (Followers: 5)
Control Systems     Hybrid Journal   (Followers: 295)
ECTI Transactions on Computer and Information Technology (ECTI-CIT)     Open Access  
ECTI Transactions on Electrical Engineering, Electronics, and Communications     Open Access  
Edu Elektrika Journal     Open Access   (Followers: 1)
Electrica     Open Access  
Electronic Design     Partially Free   (Followers: 117)
Electronic Markets     Hybrid Journal   (Followers: 7)
Electronic Materials Letters     Hybrid Journal   (Followers: 4)
Electronics     Open Access   (Followers: 97)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 10)
Electronics For You     Partially Free   (Followers: 100)
Electronics Letters     Hybrid Journal   (Followers: 26)
Elkha : Jurnal Teknik Elektro     Open Access  
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 55)
Energy Harvesting and Systems     Hybrid Journal   (Followers: 4)
Energy Storage Materials     Full-text available via subscription   (Followers: 3)
EPJ Quantum Technology     Open Access   (Followers: 1)
EURASIP Journal on Embedded Systems     Open Access   (Followers: 11)
Facta Universitatis, Series : Electronics and Energetics     Open Access  
Foundations and Trends® in Communications and Information Theory     Full-text available via subscription   (Followers: 6)
Foundations and Trends® in Signal Processing     Full-text available via subscription   (Followers: 10)
Frequenz     Hybrid Journal   (Followers: 1)
Frontiers of Optoelectronics     Hybrid Journal   (Followers: 1)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 207)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IACR Transactions on Symmetric Cryptology     Open Access  
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 99)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 80)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 49)
IEEE Journal of the Electron Devices Society     Open Access   (Followers: 9)
IEEE Journal on Exploratory Solid-State Computational Devices and Circuits     Hybrid Journal   (Followers: 1)
IEEE Power Electronics Magazine     Full-text available via subscription   (Followers: 72)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 71)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 58)
IEEE Transactions on Circuits and Systems for Video Technology     Hybrid Journal   (Followers: 26)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 42)
IEEE Transactions on Electron Devices     Hybrid Journal   (Followers: 19)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 26)
IEEE Transactions on Power Electronics     Hybrid Journal   (Followers: 78)
IEEE Transactions on Signal and Information Processing over Networks     Full-text available via subscription   (Followers: 12)
IEICE - Transactions on Electronics     Full-text available via subscription   (Followers: 12)
IEICE - Transactions on Information and Systems     Full-text available via subscription   (Followers: 5)
IET Cyber-Physical Systems : Theory & Applications     Open Access   (Followers: 1)
IET Energy Systems Integration     Open Access  
IET Microwaves, Antennas & Propagation     Hybrid Journal   (Followers: 35)
IET Nanodielectrics     Open Access  
IET Power Electronics     Hybrid Journal   (Followers: 55)
IET Smart Grid     Open Access  
IET Wireless Sensor Systems     Hybrid Journal   (Followers: 18)
IETE Journal of Education     Open Access   (Followers: 4)
IETE Journal of Research     Open Access   (Followers: 11)
IETE Technical Review     Open Access   (Followers: 13)
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems)     Open Access   (Followers: 3)
Industrial Electronics, IEEE Transactions on     Hybrid Journal   (Followers: 70)
Industrial Technology Research Journal Phranakhon Rajabhat University     Open Access  
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 35)
Informatik-Spektrum     Hybrid Journal   (Followers: 2)
Instabilities in Silicon Devices     Full-text available via subscription   (Followers: 1)
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 13)
International Journal of Advanced Research in Computer Science and Electronics Engineering     Open Access   (Followers: 18)
International Journal of Advances in Telecommunications, Electrotechnics, Signals and Systems     Open Access   (Followers: 11)
International Journal of Antennas and Propagation     Open Access   (Followers: 11)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 4)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 6)
International Journal of Control     Hybrid Journal   (Followers: 11)
International Journal of Electronics     Hybrid Journal   (Followers: 7)
International Journal of Electronics and Telecommunications     Open Access   (Followers: 13)
International Journal of Granular Computing, Rough Sets and Intelligent Systems     Hybrid Journal   (Followers: 3)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Hybrid Intelligence     Hybrid Journal  
International Journal of Image, Graphics and Signal Processing     Open Access   (Followers: 16)
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 10)
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields     Hybrid Journal   (Followers: 4)
International Journal of Power Electronics     Hybrid Journal   (Followers: 25)
International Journal of Review in Electronics & Communication Engineering     Open Access   (Followers: 4)
International Journal of Sensors, Wireless Communications and Control     Hybrid Journal   (Followers: 10)
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 4)
International Journal of Wireless and Microwave Technologies     Open Access   (Followers: 6)
International Transaction of Electrical and Computer Engineers System     Open Access   (Followers: 2)
JAREE (Journal on Advanced Research in Electrical Engineering)     Open Access  
Journal of Biosensors & Bioelectronics     Open Access   (Followers: 3)
Journal of Advanced Dielectrics     Open Access   (Followers: 1)
Journal of Artificial Intelligence     Open Access   (Followers: 11)
Journal of Circuits, Systems, and Computers     Hybrid Journal   (Followers: 4)
Journal of Computational Intelligence and Electronic Systems     Full-text available via subscription   (Followers: 1)
Journal of Electrical and Electronics Engineering Research     Open Access   (Followers: 32)
Journal of Electrical Bioimpedance     Open Access  
Journal of Electrical Bioimpedance     Open Access   (Followers: 2)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 7)
Journal of Electrical, Electronics and Informatics     Open Access  
Journal of Electromagnetic Analysis and Applications     Open Access   (Followers: 8)
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 9)
Journal of Electronic Design Technology     Full-text available via subscription   (Followers: 6)
Journal of Electronics (China)     Hybrid Journal   (Followers: 5)
Journal of Energy Storage     Full-text available via subscription   (Followers: 4)
Journal of Engineered Fibers and Fabrics     Open Access   (Followers: 2)
Journal of Field Robotics     Hybrid Journal   (Followers: 3)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 175)
Journal of Information and Telecommunication     Open Access   (Followers: 1)
Journal of Intelligent Procedures in Electrical Technology     Open Access   (Followers: 3)
Journal of Low Power Electronics     Full-text available via subscription   (Followers: 10)
Journal of Low Power Electronics and Applications     Open Access   (Followers: 10)
Journal of Microelectronics and Electronic Packaging     Hybrid Journal  
Journal of Microwave Power and Electromagnetic Energy     Hybrid Journal   (Followers: 3)
Journal of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 11)
Journal of Nuclear Cardiology     Hybrid Journal  
Journal of Optoelectronics Engineering     Open Access   (Followers: 4)
Journal of Physics B: Atomic, Molecular and Optical Physics     Hybrid Journal   (Followers: 29)
Journal of Power Electronics & Power Systems     Full-text available via subscription   (Followers: 11)
Journal of Semiconductors     Full-text available via subscription   (Followers: 5)
Journal of Sensors     Open Access   (Followers: 26)
Journal of Signal and Information Processing     Open Access   (Followers: 9)
Jurnal ELTIKOM : Jurnal Teknik Elektro, Teknologi Informasi dan Komputer     Open Access  
Jurnal Rekayasa Elektrika     Open Access  
Jurnal Teknik Elektro     Open Access  
Jurnal Teknologi Elektro     Open Access  
Kinetik : Game Technology, Information System, Computer Network, Computing, Electronics, and Control     Open Access  
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Magnetics Letters, IEEE     Hybrid Journal   (Followers: 7)
Majalah Ilmiah Teknologi Elektro : Journal of Electrical Technology     Open Access   (Followers: 2)
Metrology and Measurement Systems     Open Access   (Followers: 6)
Microelectronics and Solid State Electronics     Open Access   (Followers: 27)
Nanotechnology Magazine, IEEE     Full-text available via subscription   (Followers: 41)
Nanotechnology, Science and Applications     Open Access   (Followers: 6)
Nature Electronics     Hybrid Journal   (Followers: 1)
Networks: an International Journal     Hybrid Journal   (Followers: 5)
Open Electrical & Electronic Engineering Journal     Open Access  
Open Journal of Antennas and Propagation     Open Access   (Followers: 9)
Optical Communications and Networking, IEEE/OSA Journal of     Full-text available via subscription   (Followers: 15)
Paladyn. Journal of Behavioral Robotics     Open Access   (Followers: 1)
Power Electronics and Drives     Open Access   (Followers: 2)
Problemy Peredachi Informatsii     Full-text available via subscription  
Progress in Quantum Electronics     Full-text available via subscription   (Followers: 7)
Pulse     Full-text available via subscription   (Followers: 5)
Radiophysics and Quantum Electronics     Hybrid Journal   (Followers: 2)
Recent Advances in Communications and Networking Technology     Hybrid Journal   (Followers: 3)
Recent Advances in Electrical & Electronic Engineering     Hybrid Journal   (Followers: 9)
Research & Reviews : Journal of Embedded System & Applications     Full-text available via subscription   (Followers: 5)
Revue Méditerranéenne des Télécommunications     Open Access  
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 56)
Semiconductors and Semimetals     Full-text available via subscription   (Followers: 1)
Sensing and Imaging : An International Journal     Hybrid Journal   (Followers: 2)
Services Computing, IEEE Transactions on     Hybrid Journal   (Followers: 4)
Software Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 78)
Solid State Electronics Letters     Open Access  
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 13)
Solid-State Electronics     Hybrid Journal   (Followers: 9)
Superconductor Science and Technology     Hybrid Journal   (Followers: 3)
Synthesis Lectures on Power Electronics     Full-text available via subscription   (Followers: 3)
Technical Report Electronics and Computer Engineering     Open Access  
TELE     Open Access  
Telematique     Open Access  
TELKOMNIKA (Telecommunication, Computing, Electronics and Control)     Open Access   (Followers: 9)
Transactions on Electrical and Electronic Materials     Hybrid Journal  
Universal Journal of Electrical and Electronic Engineering     Open Access   (Followers: 6)
Ural Radio Engineering Journal     Open Access  
Visión Electrónica : algo más que un estado sólido     Open Access   (Followers: 1)
Wireless and Mobile Technologies     Open Access   (Followers: 6)
Wireless Power Transfer     Full-text available via subscription   (Followers: 4)
Women in Engineering Magazine, IEEE     Full-text available via subscription   (Followers: 11)
Електротехніка і Електромеханіка     Open Access  

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Similar Journals
Journal Cover
IEEE Journal of Emerging and Selected Topics in Power Electronics
Journal Prestige (SJR): 1.657
Citation Impact (citeScore): 7
Number of Followers: 49  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2168-6777 - ISSN (Online) 2168-6785
Published by IEEE Homepage  [191 journals]
  • IEEE Journal of Emerging and Selected Topics in Power Electronics
    • Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • IEEE Power Electronics Society Information
    • Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Guest Editorial: Special Section on Modeling, Design, and Application of
           Next-Generation Power Components
    • Authors: Francesco Iannuzzo;John Shen;
      Pages: 1422 - 1424
      Abstract: Power electronics, characterized by impressive technology advancement over the last two decades, has become a more complex and multidisciplinary research field. Power semiconductor devices, passive components and power conversion systems are undergoing significant performance improvement, but meanwhile facing challenges in efficiency, flexibility and reliability. While new wide-bandgap semiconductor devices are now establishing new efficiency and switching speed standards in the market, silicon power devices keep improving in terms of both manufacturing technology, package materials and design. Both call for new modeling methods and design efforts at device, component, and system levels, in order to accurately predict device characteristics, losses, EMI, hence allow design of power conversion systems with more precise margins. Furthermore, there is a lack of understanding of new phenomena and failure mechanisms associated with the new component technologies. From a system point of view, condition monitoring for high reliability is nowadays a musthave part in the overall application development process, demanding accurate and trustable models.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Dynamic On-Resistance in GaN Power Devices: Mechanisms, Characterizations,
           and Modeling
    • Authors: Shu Yang;Shaowen Han;Kuang Sheng;Kevin J. Chen;
      Pages: 1425 - 1439
      Abstract: Gallium nitride (GaN) power devices enable power electronic systems with enhanced power density and efficiency. Dynamic on-resistance (RON) degradation (or current collapse), originating from buffer trapping, surface trapping and gate instability, has been regarded as a primary challenge for the lateral GaN-on-Si power devices. In this paper, we present an overview and discussion of the mechanisms, characterizations, modeling, and solutions for the degradation of dynamic RON in GaN power devices. The complex dynamics of acceptor/donor buffer traps and their impacts on dynamic RON have been analyzed and revealed by TCAD simulations and high-voltage back-gating measurements. The gate instability-induced dynamic RON increase in different GaN device technologies and the role of gate overdrive are also discussed. Wafer-level and board-level characterization techniques enabling accurate dynamic RON evaluation are reviewed. The dynamic RON performance of the state-of-the-art commercial GaN devices is presented, and a behavioral model with the dynamic RON degradation taken into consideration has been implemented for circuit analysis. The latest progress in GaN device technologies for enhanced dynamic performance is also reviewed and discussed.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A Novel Kilovolts GaN Vertical Superjunction MOSFET With Trench Gate:
           Approach for Device Design and Optimization
    • Authors: Qi Zhou;Peng Huang;Yuanyuan Shi;Kuangli Chen;Dong Wei;Ruopu Zhu;Wanjun Chen;Bo Zhang;
      Pages: 1440 - 1448
      Abstract: In this paper, a gallium nitride (GaN) vertical superjunction (SJ) MOSFET with trench gate is proposed and studied by the TCAD simulation. In order to achieve the typical electric field (E-field) modulation effect by the P+/N/N+ structure in the conventional Si SJ-MOS, the P-GaN/unintentional doped (UID)GaN/N+-GaN stack is alternatively used by taking into account the unavailability of P+-GaN. In this manner, the P-GaN and N+-substrate serve as the field-stop (FS) layers in the proposed GaN SJ-MOS. In the forward bias, the enhancement-mode function of the device is enabled by the gated side-wall and aperture composite channel that leads to a 1.47-V threshold voltage of the device. In the reverse bias, the breakdown of the device is governed by two mechanisms: 1) the punchthrough (PT) in the top P-GaN/N-drift junction due to the possible under design of the P-GaN thickness; 2) the avalanche breakdown triggered by high E-field due to the possible under design of the bottom UID-GaN thickness. Hence, from the uniform E-field distribution point of view, a device optimization approach for GaN vertical SJ-MOS is proposed. The hole and electron densities of P-GaN and N-drift are optimized to achieve a uniform E-field distribution in the device both in the lateral and vertical directions, which is found to be 6 × 1016 cm-3. Moreover, the thickness ratio of P-GaN/UID-GaN is designed to obtain an identical intrinsic breakdown for the top P-GaN/Ndrift junction and bottom UID/N-drift region, which enables the maximum Baliga's figure-of-merit (BFOM) of the device. The concept of device design and optimization is of great interests for GaN vertical device for over kilovolts applications.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Vertical GaN Power Transistor With Intrinsic Reverse Conduction and Low
           Gate Charge for High-Performance Power Conversion
    • Authors: Ruopu Zhu;Qi Zhou;Hong Tao;Yi Yang;Kai Hu;Dong Wei;Liyang Zhu;Yuanyuan Shi;Wanjun Chen;Bo Zhang;
      Pages: 1449 - 1455
      Abstract: In this paper, a novel vertical normally-off GaN power transistor featuring a split gate with the intrinsic reverse conduction (RCVFET) and low gate charge is proposed. The static and dynamic device characteristics are studied and analyzed by simulation with Sentaurus TCAD. Benefiting from the monolithically integrated freewheeling diode, the RCVFET characteristics of the device are independent with the threshold voltage VTH, while a low reverse turn-on voltage VR,ON of 0.8 V is obtained. The RCVFET exhibits a short reverse recovery time Trr of 13 ns and low reverse recovery charge Qrr of 47 nC. Due to the split-gate design, the gate charge of the RCVFET is also significantly reduced, favoring the improved switching speed and lower switching power loss. QGD is as low as 80 nC which is only 20% of that in the reference device without splitgate design. Accordingly, the turn-off transient time and power dissipation of the RCVFET are reduced by 45% and 55.7%, respectively. Meanwhile, the device exhibits a low on-resistance RON of 0.98 mQ · cm2 and a high breakdown voltage (BV) of 1.8 kV.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • $R_{text{ON}}$+ +Characterization+in+Power+Electronics+Applications&rft.title=IEEE+Journal+of+Emerging+and+Selected+Topics+in+Power+Electronics&rft.issn=2168-6777&rft.date=2019&rft.volume=7&rft.spage=1456&rft.epage=1464&rft.aulast=Rodríguez;&rft.aufirst=Pedro&rft.au=Pedro+Javier+Martínez;Pablo+Fernández+Miaja;Enrique+Maset;Juan+Rodríguez;">A Test Circuit for GaN HEMTs Dynamic $R_{text{ON}}$ Characterization in
           Power Electronics Applications
    • Authors: Pedro Javier Martínez;Pablo Fernández Miaja;Enrique Maset;Juan Rodríguez;
      Pages: 1456 - 1464
      Abstract: Wide bandgap devices such as gallium nitride (GaN) high electron mobility transistors (HEMTs) are a promising technology in the field of power electronics. Due to the physical properties of the GaN and the device design, they can outperform their silicon counterparts for the design of highly efficient power switching converters. However, its design should face certain effects that can diminish its performance. One such effect is the degradation mechanism known as dynamic ON-resistance (dynamic RON), being its mitigation one of the main objectives in the design of the device. In this paper, a circuit is proposed for assessing if this effect is present in GaN transistors in power electronics applications. The circuit allows testing the GaN HEMTs with different stress voltages and times maintaining the desired current level, and allows for repeating the test in successive switching pulses, with adjustable switching frequency and duty cycle, always with the same current, mimicking a real power electronics application.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Investigation of Surge Current Capability of GaN E-HEMTs in The Third
           Quadrant: The Impact of P-GaN Contact
    • Authors: Yinxiang Liu;Shu Yang;Shaowen Han;Kuang Sheng;
      Pages: 1465 - 1474
      Abstract: Gallium nitride (GaN) enhancement-mode high-electron-mobility transistors (E-HEMTs), featuring an inherently symmetric lateral channel, are highly favorable for both forward and reverse conduction in bidirectional DC/DC converter and DC/RF interconversion systems. Under the circumstances of current overshoot/oscillation, the GaN E-HEMTs would undergo a high surge current in the third quadrant which could possibly result in device failure. In this paper, the surge current capabilities of two types of commercial GaN E-HEMTs in the third quadrant are evaluated, whereby the impacts of different p-GaN technologies and gate-to-source voltage (VGS) are revealed. The ohmic p-GaN contact and high VGS, enabling higher efficiency of hole injection and channel modulation, can enhance the surge current capability of GaN E-HEMTs in the reverse conduction mode. To our best knowledge, it is the first time to investigate the surge current capability and to reveal the underlying mechanisms in lateral GaN power devices.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Design and Simulation of GaN Superjunction Transistors With 2-DEG Channels
           and Fin Channels
    • Authors: Ming Xiao;Ruizhe Zhang;Dong Dong;Han Wang;Yuhao Zhang;
      Pages: 1475 - 1484
      Abstract: High-performance 2-D-electron-gas (2-DEG) channel and submicron fin-shaped channel have recently been demonstrated in vertical GaN power transistors. This indicates that, unlike Si and SiC, the inversion-type metal-oxide-semiconductor channel is no longer the “default option” for future GaN superjunction transistors. This paper demonstrates the design and simulation of GaN superjunction transistors with 2-DEG and fin channels, i.e., a superjunction current-aperture vertical electron transistor (SJ-CAVET) and a superjunction fin field-effect-transistor (SJ-FinFET). A breakdown voltage over 2.2 kV and a specific on-resistance (RON,sp) of 0.35 mQ · cm2 were demonstrated in the simulated GaN SJ-CAVETs and SJ-FinFETs with 10-μm-thick superjunction region. Mixed-mode simulations were used to evaluate their performance in 1.7 kV, 50-A power switching applications. Their RON,sp and die size are at least 30-to-50-fold smaller than that of today's best 1.7-kV power transistors. Thanks to the smaller die size, the junction capacitances and switching charges are significantly smaller, allowing for a megahertz practical switching frequency which is at least tenfold higher than today's 1.7-kV power transistors. The simulations of higher voltage GaN SJ-CAVETs and SJ-FinFETs up to 10 kV reveal consistent advantages over commercial transistors. These results show the great potentials of GaN SJ-CAVETs and SJ-FinFETs for future medium-voltage high-frequency power applications.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Analytical Switching Loss Model for GaN-Based Control Switch and
           Synchronous Rectifier in Low-Voltage Buck Converters
    • Authors: Yajie Xin;Wanjun Chen;Ruize Sun;Yijun Shi;Chao Liu;Yun Xia;Fangzhou Wang;Maolin Li;Jia Li;Qi Zhou;Xiaochuan Deng;Tangsheng Chen;Zhaoji Li;Bo Zhang;
      Pages: 1485 - 1495
      Abstract: In this paper, an analytical switching loss model for a gallium nitride (GaN) based control switch (CS) and synchronous rectifier (SR) in low-voltage buck converters is proposed. Based on the consideration of parasitic inductances, SR reverse conduction voltage drop, and overshoot current effect caused by output capacitance of SR, the total switching loss is modeled with regard to both CS and SR, which can lead to more accurate prediction of power loss and system efficiency in low-voltage buck converters. The modeling results show that the percentage of SR switching loss in total switching loss is 25.4% in the 12-1.2-V converter, which is far larger than the 6.3% in the 48-5-V converter, and this verifies the necessity of including SR into the model for low-voltage converters. Experiment results exhibit an average increase of 52.3% and 66.1% in the accuracy of predicted system efficiency and converter power loss through the proposed model with SR than conventional models from 400 kHz to 1 MHz.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • 1.2-kV 4H-SiC Merged PiN Schottky Diode With Improved Surge Current
           Capability
    • Authors: Jiupeng Wu;Na Ren;Hengyu Wang;Kuang Sheng;
      Pages: 1496 - 1504
      Abstract: This paper presents the design and experimental analysis of 1200-V 4H-silicon carbide (SiC) merged PiN Schottky (MPS) diodes. Design considerations and device performances of the MPS diodes are compared with those of the junction barrier Schottky (JBS) diodes via numerical simulation and experiments. Due to the limited P+ width/ratio in JBS diodes, p-n junction is not turned on until very high current/voltage bias is applied. This increases the device voltage drop and energy dissipation in high current stress conditions. Thanks to the wide P+ region design and the ohmic contact on the P +regions, the p-n junction turn-on voltage in MPS diodes is substantially decreased, and the surge current capability is improved accordingly. Furthermore, the surge capability of two layouts of the MPS diodes are compared. Layout A with ~60% high P+ ratio can improve the surge current capability by 10% and 20% compared with layout B design (with ~50% P+ ratio) and pure JBS diode (with ~40% P+ ratio), respectively. The reliability of the MPS diodes is studied by repetitive pulse surge current tests. No obvious degradation appears after 5500 test cycles under a surge current stress 20 times the device nominal current rating.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Multizone Gradient-Modulated Guard Ring Technique for Ultrahigh Voltage
           4H-SiC Devices With Increased Tolerances to Implantation Dose and Surface
           Charges
    • Authors: Xiaochuan Deng;Shufeng Gao;Ben Tan;Juntao Li;Xuan Li;Chengzhan Li;Wanjun Chen;Zhaoji Li;Bo Zhang;
      Pages: 1505 - 1512
      Abstract: An area efficient multizone gradient-modulated guard ring (MGM-GR) edge termination technique is proposed, fabricated, and analyzed for 10-kV class silicon carbide devices without extra process steps or masks, which provides a better tradeoff between near ideal blocking capabilities and technological process complexity. The edge termination region is divided into multiple zones by employing MGMGR technique, which forms a similar linearly graded doping profile to relieve the amount of electric field crowding at the periphery of the active area and achieve a maximum blocking voltage with wide tolerance to implantation dose. The proposed device shows not less than a 35% reduction in edge termination area in comparison with a conventional equally spaced ring at a breakdown voltage of 10 kV. Moreover, MGM-GR shows good tolerances to breakdown voltage for total implant dose and interface charges. With the application of MGM-GR technique to SiC MOSFET with a 100-μm-thick N- epilayer doped to 5 × 1014 cm-3, the measured breakdown voltage is 13.6 kV at 10 μA. This voltage is nearly 95% of the theoretical value calculated for a 1-D structure. Simulated and measured characteristics show that MGM-GR structure is a candidate for an ultrahigh voltage power device to maximize power density and driving down system complexity.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Optimization Design of Isolation Rings in Monolithically Integrated 1200V
           SiC Transistor and Antiparallel Diode for Improved Blocking Voltage
    • Authors: Shiwei Liang;Jun Wang;Fang Fang;Linfeng Deng;Z. John Shen;
      Pages: 1513 - 1518
      Abstract: Monolithic integration of antiparallel diode with power transistor offers unique advantages for wide bandgap (WBG) power devices. However, the blocking voltage degradation issue stands in the way in the development of the integrated devices. This paper presents the design, fabrication, and verification of a monolithically integrated SiC BJT and antiparalleled junction barrier Schottky (JBS) diode (BJT/JBS), which has achieved a blocking voltage very close to that of the individual transistor or diode. It introduces isolation rings into the border region, separating the transistor and diode. The design was first validated successfully by TCAD simulations, and then some integrated device samples were fabricated to experimentally verify the feasibility of the isolation rings in improving their blocking voltages. Besides, the fabrication of the 4H-SiC-integrated BJT/JBS switch adopted a single metal, single thermal treatment process to form ohmic contacts on p± regions and Schottky contacts on the N-epilayer simultaneously. Hence, there was not any additional step added to the SiC BJT baseline process. A breakdown voltage of 1340 V at a leakage current of 10 μA is experimentally observed, and the simulation results and design optimization are discussed.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Design and Characterization of Area-Efficient Trench Termination for
           4H-SiC Devices
    • Authors: Hengyu Wang;Jue Wang;Li Liu;Na Ren;Jiupeng Wu;Ce Wang;Shu Yang;Kuang Sheng;
      Pages: 1519 - 1526
      Abstract: In this paper, the operation mechanism of trench termination is investigated through 2-D numeric simulation on Silvaco. It is found that in trench termination, the electric field is terminated by the accumulated holes at the outer trench sidewall. In order to ensure a high termination breakdown voltage, the trench is refilled with a combination of SiO2 and polyimide (PI). Through various 2-D numerical simulations, the impact of structural parameters on breakdown voltage has been discussed, namely, trench depth (TD), trench width (TW), and sidewall tilt angle. The 3-D simulations are also conducted to investigate the effect of round corner radius on the device breakdown voltage and electric field in the dielectrics. Based on these results, the trench termination is designed and then fabricated along with a p-i-n diode. The measurement results show that a 14 μm wide trench is sufficient to terminate a voltage of 1750V (>96% of the ideal planar breakdown). Comparing with conventional field limiting rings junction termination extension (FLR/JTE) technology, this trench termination can significantly reduce the termination length by a factor of 4. As a result, the area efficiency is largely improved from 62% to around 90% for a 2A device conducting at 1000 A/cm2. These results indicate that the SiC device price can be substantially lowered with such an areaefficient trench termination technology. Furthermore, the 168-h high-temperature reverse bias (HTRB) test under 1200 V and 175 °C shows the potential of this trench termination for longterm reliable operation. Finally, unclamped inductive switching (UIS) tests have been conducted on fabricated devices. Compared to commercial SiC junction barrier Schottky diodes with FLR, fabricated p-i-n diodes with trench termination show significant higher avalanche capability.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Statistical Analysis of the Electrothermal Imbalances of Mismatched
           Parallel SiC Power MOSFETs
    • Authors: Alessandro Borghese;Michele Riccio;Asad Fayyaz;Alberto Castellazzi;Luca Maresca;Giovanni Breglio;Andrea Irace;
      Pages: 1527 - 1538
      Abstract: Thanks to the increasing availability of silicon carbide (SiC) metal oxide semiconductor field effect transistors (MOSFETs) with outstanding static and dynamic performances, the number of applications in which these devices are used is rapidly growing. Despite that, the maximum current rating of such devices is usually limited at few hundred amps, which sets an upper bound for the power level at which these transistors can be adopted. A viable solution to this problem consists in paralleling several SiC MOSFETs. However, the design of parallel configurations needs optimization since mismatched performances can cause the enhanced stress of a subset of devices, which can ultimately lead to premature failure of the whole module. In this contribution, several sets of Monte Carlo (MC) electrothermal simulations of parallel SiC MOSFETs are used to systematically relate the deviations of devices and circuit parameters to the resulting uneven power dissipation. To this purpose, a set of relevant parameters is identified and statistically described. Thereafter, the simulation of a 200-kHz synchronous buck converter relying on mismatched parallel MOSFETs is performed as a case study. Eventually, a methodology to derive a guideline for the design of reliable multichip configurations is developed. The methodology is based on the iteration of MC simulations for different tolerances of the parameters.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • $V_{mathrm{TH}}$+ +Instability+of+a+1.2-kV+SiC+Power+MOSFET&rft.title=IEEE+Journal+of+Emerging+and+Selected+Topics+in+Power+Electronics&rft.issn=2168-6777&rft.date=2019&rft.volume=7&rft.spage=1539&rft.epage=1546&rft.aulast=Chen;&rft.aufirst=Jiahui&rft.au=Jiahui+Sun;Jin+Wei;Zheyang+Zheng;Yuru+Wang;Kevin+J.+Chen;">Short Circuit Capability and Short Circuit Induced $V_{mathrm{TH}}$
           Instability of a 1.2-kV SiC Power MOSFET
    • Authors: Jiahui Sun;Jin Wei;Zheyang Zheng;Yuru Wang;Kevin J. Chen;
      Pages: 1539 - 1546
      Abstract: The withstand capability and threshold voltage (VTH) instability of 1.2-kV silicon carbide (SiC) MOSFETs under repetitive short circuit (SC) tests are investigated. An SC test system is constructed to apply repetitive SC stress to SiC MOSFETs and measure the transfer I-V characteristics and gate-to-source leakage current (IGSS) after each set of SC tests. To evaluate the SC capability, repetitive SC tests with different SC durations (tp) are conducted until device failure. The SC withstand time (SCWT) at 1000 SC cycles is found to be ~3.3 μs. VTH instability under repetitive SC tests prior to the device failure is characterized. A bidirectional VTH shift behavior, i.e., negative shift at shorter tp and positive shift at longer tp, was revealed. The VTH shifts under repetitive SC tests are attributed to the SC pulse process according to the results of high-temperature reverse bias (HTRB) and dynamic high-temperature gate bias (HTGB) tests. The underlying mechanisms of the complex VTH shift behavior are explained in a unified framework by taking into account the junction temperature (Tj) increase with longer tp. TCAD device simulation is used to help analyze the mechanisms.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A Physics-Based Lumped-Charge Model for SiC MPS Diode Implemented in
           PSPICE
    • Authors: Yaoqiang Duan;Fei Xiao;Yingjie Jia;Yifei Luo;Binli Liu;
      Pages: 1547 - 1555
      Abstract: This paper presents a physical lumped-charge model for an SiC merged p-i-n Schottky (MPS) diode. According to the MPS chip configuration, this paper divides the model into two parts: the bipolar subcircuit and the unipolar subcircuit. Both the two parts are modeled by the lumped-charge approach. The proposed physics-based model is also temperature dependent. The model is implemented into the PSPICE simulator in the form of an equivalent circuit. For the characterization of surge current condition that will cause chip temperature changes significantly, an accurate lumped thermal model of the module is established by the structural parameters extraction with a scanning electron microscope. Finally, the developed model is verified by Cree CAS300M12BM2 SiC power module with a 2000-A surge current through the electro-thermal co-simulation. Besides, a test setup is built up with an ultrafast infrared (IR) camera to validate the electro-thermal model in the circuit-level simulation.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A SiC JFET-Based Solid State Circuit Breaker With Digitally Controlled
           Current-Time Profiles
    • Authors: Dong He;Zhikang Shuai;Zhiqi Lei;Wei Wang;Xue Yang;Z. John Shen;
      Pages: 1556 - 1565
      Abstract: DC distribution networks are able to effectively improve the energy efficiency and easy integration of distributed generations. However, the reliable dc circuit breaker is an essential requisite for the wide application of dc power. This paper proposes a self-powered solid-state circuit breaker (SSCB) with a digitally controlled current-time profile for both ultrafast short-circuit protection and overcurrent protection. The fault detection unit detects short-circuit or overcurrent conditions by sensing the sampling resistance voltage and delivers these voltage signals to a low-cost microprocessor to realize the protection operation of the SSCB. A pulsewidth modulation (PWM) current limiting protection method with time interval Td is proposed to avoid nuisance tripping caused by inrush current during power electronic load startup. The time interval is properly selected based on the transient thermal properties of silicon carbide (SiC) junction gate field-effect transistors (JFETs). In order to verify the dynamic response of the SSCB, a SiC JFET-based circuit breaker prototype is designed and fabricated for result confirmation.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Dynamic Voltage Balancing for the High-Voltage SiC Super-Cascode Power
           Switch
    • Authors: Xintong Lyu;He Li;Zhuxuan Ma;Boxue Hu;Jin Wang;
      Pages: 1566 - 1573
      Abstract: Presented in this paper is an optimization method to improve the dynamic performance of high-voltage supercascode power switches (SCPSs) by implementing silicon carbide (SiC) junction field-effect transistor (JFET). The basic operating principle of SCPS is explained at the beginning of the paper. Equivalent circuit models are outlined next, with equations describing the voltage distribution among each SiC JFET during switching transients. Based on the sensitivity analysis, a component optimization method for balancing the SCPS internal voltage is proposed, which effectively eliminates the overvoltage. This significantly reduces the switching loss and the chance of diode avalanche. Compared with the nonoptimized case, the turn-on loss of the SCPS is reduced to 8.85%, and the turn-off loss reduces to 48.4%.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • DC Modeling and Geometry Scaling of SiC Low-Voltage MOSFETs for Integrated
           Circuit Design
    • Authors: Shamim Ahmed;Arman Ur Rashid;Md Maksudul Hossain;Tom Vrotsos;A. Matthew Francis;H. Alan Mantooth;
      Pages: 1574 - 1583
      Abstract: This paper presents the SPICE model development of the static characteristics of silicon carbide (SiC) lateral n-channel and p-channel MOSFETs based on the widely used BSIM4 compact model. The methodology for length and width scaling of the MOSFETs is demonstrated. The transfer (ID-VG) and output (ID-VD) characteristics of the SiC low-voltage MOSFETs are significantly different from their Si counterparts mainly due to the presence of the interface trapped charge, and proper modifications of the dc equations are required to accurately model the characteristics. The relatively poorer quality of the oxide-semiconductor interface in a SiC MOSFET compared to Si gives rise to valid energy states inside the bandgap. The trapped charges in these interface states are responsible for mobility degradation, higher subthreshold slope (SS), soft saturation, increase in the flat band and threshold voltage, and exaggerated body effects. In this paper, the effects of the interface trapped charge on the static characteristics of the SiC MOSFETs are intensively studied and accurate compact models are developed and incorporated in the core BSIM4 dc current equations to accurately model the SiC MOSFET I-V behavior. A new parameter extraction sequence is also proposed to optimize the model and the simulated characteristics are matched with the measured characteristics of SiC MOSFET devices.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Modeling of IGBT With High Bipolar Gain for Mitigating Gate Voltage
           Oscillations During Short Circuit
    • Authors: Paula Diaz Reigosa;Francesco Iannuzzo;Chiara Corvasce;Munaf Rahimo;
      Pages: 1584 - 1592
      Abstract: In this paper, the impact of the p-n-p bipolar transistor gain on the short-circuit behavior of high-voltage trench insulated-gate bipolar transistors (IGBTs) is analyzed. The short-circuit ruggedness against high-frequency oscillations is strongly improved by increasing the hole current supplied by the collector. By doing so, the electric field at the emitter of the IGBT is increased and less influenced by the amount of the excess charge (i.e., the electric field is fixed). The charge-field interactions during the short circuit event, leading to periodic charge storage and charge removal effect and provoking miller capacitance variations, can be mitigated. The effectiveness of using IGBTs with a high bipolar gain is validated through both simulations and experiments, also a design rule to tradeoff the IGBT's losses and short-circuit robustness is provided.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A Multi-timescale Prediction Model of IGBT Junction Temperature
    • Authors: Binli Liu;Fei Xiao;Yifei Luo;Yongle Huang;Youxing Xiong;
      Pages: 1593 - 1603
      Abstract: Based on the features of different timescales and according to the characteristics of loss and heat transfer under those cases, a multi-timescale prediction model (MTPM) of insulated gate bipolar transistor (IGBT) junction temperature is presented in this paper, including a short-duration transient microsecond prediction model based on the semiconductor physical model and the theorem of heat absorption and emission, an unsteady millisecond-scale prediction model based on the equivalent switching loss set in databook and the order-reduced thermal model, and a steady second-scale prediction model based on the characteristics of a fundamental wave fluctuating periodically at junction temperature and the equivalent first-order thermal model. An experimental system has been designed and established for the verification of the proposed MTPM of IGBT junction temperature according to a corresponding timescale. The comparison result shows that the error between simulation and experiment is less than 5% and simulation efficiency is significantly improved.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Application of Nonlinear Fracture Mechanics Parameter to Predicting
           Wire-Liftoff Lifetime of Power Module at Elevated Temperatures
    • Authors: Nobuyuki Shishido;Yutaka Hayama;Wataru Morooka;Seiya Hagihara;Noriyuki Miyazaki;
      Pages: 1604 - 1614
      Abstract: Power modules are utilized for electric power control and play a key role in efficient energy conversion. A structural reliability problem of wire bonding, wire-liftoff, in power modules becomes important at high-temperature operation. Wire-liftoff is a thermal fatigue phenomenon caused by thermal stress due to mismatch of coefficients of thermal expansion between a wire and a chip material. According to experimental studies, a saturation phenomenon of wire-liftoff lifetime was observed in power modules above the maximum junction temperature of 200 °C. In this paper, we examine the failure models for predicting wire-liftoff lifetime proposed in the previous studies and also propose a new failure model based on the nonlinear fracture mechanics parameter T*-integral range AT*. Among various failure models, the proposed model is the best to represent a saturation phenomenon of wire-liftoff lifetime. For practical use of the failure model based on ΔT*-integral range, we propose a simple calculation method of ΔT*-integral range that can be calculated by using the commercial finite element computer code such as Marc, Ansys, and so on.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Modeling and Analysis of a New Pressure Contact Package for High-Current
           Large-Die IGBTs
    • Authors: Zhong Zeng;Jun Wang;Feng Li;Xin Yin;Z. John Shen;
      Pages: 1615 - 1626
      Abstract: Megawatt-class power converters need insulated gate bipolar transistors (IGBTs) with kiloampere current ratings. Conventional IGBT power modules face difficulty to meet the reliability and over-current requirements due to bond wires, solder joint, and single-side cooling limitations. Press-pack IGBTs overcome these drawbacks, but demands extremely tight tolerance control in chip screening and matching, module parts manufacturing, and assembly. In this paper, a new pressure contact package for high-current large-die IGBTs is proposed, modeled, and experimentally studied to allow a simpler packaging process. A large IGBT die, many times the size of a typical IGBT die, is designed with a unique layout of multiple segmented emitter pads and a common gate pad. A patterned polymer positioning frame is placed onto the die. Metal contact spacers are placed in the openings of the frame to connect the emitter lid to the IGBT emitter sectors. A collector contact disc is placed between the IGBT die and the collector lid. Finite-element (FE) analysis is conducted to evaluate the mechanical and thermal performance of the new package. A 3300-V, 14-cm2 active area, round-shape IGBT die is fabricated and packaged. Excellent electrical and thermal characteristics are demonstrated to validate the feasibility of the IGBT and package concept.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Design and Characterizations of a Planar Multichip Half-Bridge Power
           Module by Pressureless Sintering of Nanosilver Paste
    • Authors: Wen Liu;Yunhui Mei;Yijing Xie;Meiyu Wang;Xin Li;Guo-Quan Lu;
      Pages: 1627 - 1636
      Abstract: A planar phase-leg 650-V/240-A insulated-gate bipolar transistor (IGBT) module with 16 IGBT chips and 16 free-wheeling diodes has been demonstrated by pressureless sintering nanosilver paste to achieve extremely high power density and low parasitic inductance. Nanosilver paste was chosen as the die-attach material to increase the operation temperature as well as the power density and heat dissipation. The thermal coupling effect of so many power chips in parallel and the thermal performance of the planar IGBT module have been discussed. The electrical performance has also been characterized to verify the feasibility of the packaging process. The I-V curves between the two bridge arms were in good consistency, resulting from the symmetrical architecture. The low switching loss of the multichip planar IGBT module can be attributed to its low parasitic inductance since the removal of bonding wires and compact architecture. Thermomechanical reliability has also been investigated by the passive thermal shocking test of the module from -55 °C to 150 °C. In addition, the increment of VCE(sat) of the modules reached the failure standard until 900 cycles.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Reliability Improvement of a Double-Sided IGBT Module by Lowering Stress
           Gradient Using Molybdenum Buffers
    • Authors: Meiyu Wang;Yunhui Mei;Wen Liu;Yijing Xie;Shancan Fu;Xin Li;Guo-Quan Lu;
      Pages: 1637 - 1648
      Abstract: A double-sided 1200-V/600-A multichip half-bridge insulated gate bipolar transistor (IGBT) module was fabricated utilizing molybdenum as stress-relief buffer and sintered nanosilver as die-attachment. By using the double-sided packaging, the volume, parasitic inductance, and junction temperature were decreased significantly, and thus the higher power density could be achieved. However, the thermomechanical stress was also increased. In this paper, molybdenum instead of the most common copper was used as a stress-relief buffer between chips and substrate, and thus the thermomechanical stress decreased greatly without significantly increasing the junction temperature. Specifically, by using molybdenum instead of copper as the buffer material, the simulation results showed that the IGBT junction temperature at total power loss of 200 W only increased by 5.2% (2.22 °C), but the corresponding thermomechanical stress decreased by 9.8% (5.58 MPa), and the sintering residual stress decreased by 20.1% (48.88 MPa). Thermal performance, static and dynamic electrical performance, and reliability via power cycling test of the double-sided module were also characterized experimentally. No degradation of the power devices proved that the way to double-sided packaging power devices could be used for future manufacturing of high-power density power module.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A Simplification Method for Power Device Thermal Modeling With
           Quantitative Error Analysis
    • Authors: Yi Zhang;Huai Wang;Zhongxu Wang;Yongheng Yang;Frede Blaabjerg;
      Pages: 1649 - 1658
      Abstract: To evaluate the reliability of power electronic systems, it is necessary to estimate the junction temperatures of power devices under periodic power loss profiles due to the fundamental-frequency current. However, a large number of periodic power loss profiles under long-term reliability evaluation (e.g., 1 year) are challenging to compute quickly. On the other hand, in order to improve computational efficiency, unvalidated simplified thermal analysis methods may impair the confidence of the reliability outcome. Therefore, this paper proposes an analytical model for power semiconductors with a compromise of the thermal estimation accuracy and computational efficiency. With the proposed model, it is indicated that minimum computation efforts can be obtained for thermal estimation under a maximum allowable error. The proposed method, thus, enables computation-efficient thermal stress analysis for power semiconductor devices with a preset modeling error. The effectiveness of the proposed method has been verified by simulations and experiments on a power electronic system with 1200-V/50-A insulated gate bipolar transistor (IGBT) modules.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Stress-Based Model for Lifetime Estimation of Bond Wire Contacts Using
           Power Cycling Tests and Finite-Element Modeling
    • Authors: Nausicaa Dornic;Zoubir Khatir;Son Ha Tran;Ali Ibrahim;Richard Lallemand;Jean-Pierre Ousten;Jeffrey Ewanchuk;Stefan V. Mollov;
      Pages: 1659 - 1667
      Abstract: In this paper, a lifetime model for bond wire contacts of insulated gate bipolar transistors (IGBT) power modules is reported. This model is based on power cycling tests obtained under accelerated conditions, and a finite-element model taking into account the electrical, thermal, and mechanical coupling. It allows us to estimate the bond wire lifetime for a large scale of junction temperature swing amplitudes (ΔTj) and stress durations (tON). To build it, a numerical design of experiment was performed in both high and low stress values (ΔTj). Then, a strain-life curve has been constructed where the average strain values on a defined volume around the contact areas between top-metallization and the most exposed bond wires to fatigue and liftoff have been used. As a result, it has been shown that the total strain is linearly dependent with ΔTj and power law dependent with tON. The combination of the strain-life relation and the strain dependency with stress parameters leads to the lifetime relationship. The obtained lifetime model has been satisfactorily validated with some additional experimental points obtained from literature and with a large range of values for tON. This methodology can be easily replicated to other structures and is quite generic.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Multiphysics Simulation Analysis and Design of Integrated Inverter Power
           Module for Electric Compressor Used in 48-V Mild Hybrid Vehicles
    • Authors: Jihwan Seong;Sang Won Yoon;Semin Park;Minki Kim;Jangmuk Lim;Jaejin Jeon;Hobeom Han;
      Pages: 1668 - 1676
      Abstract: This paper presents designs, multiphysics finite-element method (FEM) and circuit simulations, and experimental validations of a three-phase inverter power module for an electric compressor (e-Compressor) used in 48-V mild hybrid vehicles. The inverter module is integrated with its motor and scroll. The integration and e-Compressor operation situations raise sequential challenges in the module design and analysis. Thus, the e-Compressor module employs a direct bonded copper (DBC) substrate on which MOSFET dies, shunt resistors, and other electronics are soldered. Multiphysics FEM and circuit simulations are conducted to analyze (and minimize) the parasitic and loop inductances, current concentration, and temperature elevation of the design. The modeling and simulation processes are customized to represent the integrated DBC-based e-Compressor module, including the determination of loop inductance and overshoot voltage by considering systemic current conduction and reasonable simplification of cooling fluid effects. The simulation process and module performances are validated by experiments. The designed e-Compressor inverter module is improved to fully satisfy all the required specifications. Moreover, an excellent agreement between the simulation and the experimental results is confirmed, demonstrating the similar reductions of: 1) loop inductances simulated by FEM (~57%); 2) circuit-simulated overshoot voltages (~47%); and 3) experimentally measured overshoot voltages (~53%).
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A Review on Electrothermal Modeling of Supercapacitors for Energy Storage
           Applications
    • Authors: Li Wei;Ming Wu;Mengdi Yan;Shuai Liu;Qiang Cao;Huai Wang;
      Pages: 1677 - 1690
      Abstract: Supercapacitors (SCs) are drawing more and more attention in energy storage applications. This paper aims to discuss the state of the art of application-oriented electrothermal modeling methods for SCs and identify the limitations and future research opportunities. Electrothermal modeling is essential to model-based design, thermal management, and reliability analysis of SCs for energy storage applications. The review provides new perspectives with respect to the existing surveys, which focus mainly on materials, cell voltage balancing, electrical equivalent circuit models, and energy management systems. It covers the main aspects of electrothermal modeling of electric double-layer capacitors (EDLCs) and hybrid SCs, from heat generation mechanisms to different modeling and parameterization approaches. The outcome of the review is an archive of important research work in the topic area and an outlook on future efforts to be made.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Design, Modeling, and Optimization of a Coaxial Cable-Embedded Flexible
           Inductor for Wearable Applications
    • Authors: Mofan Tian;Xu Yang;Yang Chen;Wenjie Chen;Laili Wang;
      Pages: 1691 - 1702
      Abstract: Flexible and bendable inductors have attracted increasing attention because of their broad application prospects in power supplies for wearable devices. This paper proposes a coaxial flexible inductor that consists of a cable-embedded bendable magnetic core and a copper conductor. The inductor's design, modeling, and optimization procedure are presented in detail. This flexible inductor can eliminate the rigid block of a discrete inductor from the wearable device, making it more comfortable to wear. Also, because its heat distribution is more uniform, the surface temperature of the inductor can be greatly reduced. The inductor's inductance, losses, and flexibility have been modeled using geometric parameters, the current waveform, and material characteristics of ferrite sheets. These derived models can be used to optimize the inductor. A case study of a 1-μH inductor used in a 3.3-5-V 5-W boost converter has been performed to exemplify this procedure. Finally, based on the optimization results, a prototype has been fabricated and experimentally tested. The results verify the good performance of the cable-embedded inductor and the effectiveness of the optimization method.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Continuum Modeling of Inductor Magnetic Hysteresis and Eddy Currents in
           Resonant Circuits
    • Authors: Jason Pries;Emre Gurpinar;Lixin Tang;Timothy A. Burress;
      Pages: 1703 - 1714
      Abstract: This paper presents a high-fidelity finite-element modeling technique for magnetic hysteresis and eddy current losses in toroid inductors. The method is based on the separation of ferromagnetic loss characteristics into two components: a quasi-static hysteresis component and a dynamic eddy current component. The Preisach model is used to describe the quasi-static magnetic hysteresis behavior of the core, providing strong guarantees on the reproducibility of the experimentally measured characteristics. This model is used to represent the magnetic field constitutive relationships within a finite-element framework combining the effects of hysteresis and eddy currents in a unified dynamic simulation. The finite-element model of the toroid is used as a high-order inductor model coupled to a resonant circuit simulation. The modeling technique is validated through experimental measurements on two different series RLC circuits. The first circuit is based on an M19 electrical steel toroid having resonant frequency near 200 Hz. The second circuit is based on a T38 ferrite toroid having a resonant frequency near 10 kHz. The models agree closely with the measured voltages, currents, and losses. The models also successfully predict discontinuities in the measured frequency responses due to the existence of bistable operating regimes.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Medium-Voltage SiC-Based Converter Laminated Bus Insulation Design and
           Assessment
    • Authors: Yue Xu;Xianyong Feng;Jun Wang;Chaofei Gao;Rolando Burgos;Dushan Boroyevich;Robert E. Hebner;
      Pages: 1715 - 1726
      Abstract: Laminated bus has been widely used in power converters for decades. Thicker insulation increases parasitic inductance, weight, and size of the bus and decreases cooling performance and power density. Thus, it is desired to have thinner insulation for achieving the desired lifetime. The emerging medium-voltage (MV) SiC-based converters require fast switching transients and high power density, which make the optimal laminated bus design challenging. Since the internal partial discharges (PDs) can significantly degrade insulation, they should be eliminated in the design stage to ensure optimal performance. However, insulation overdesign does not necessarily help remove PD from internal defects and air pockets in the laminated bus. In order to obtain a PD-free laminated bus with thin insulation, this article uses representative structures to show a path for removing internal PDs. This paper presents a systematic approach to remove air pockets and reduce the impact of the unavoidable defects in adhesive layers through theoretical and experimental studies. In addition, a proper material selection and processing method are derived to reduce the size and number of internal defects while leading to a more favorable electric field distribution. The PD experimental results suggest the effectiveness of the proposed approach.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • An Improved Proportional Base Driver for Minimizing Driver Power
           Consumption of SiC BJT Over Wide Current and Temperature Range
    • Authors: Shiwei Liang;Jun Wang;Linfeng Deng;Yize Shi;Xin Yin;Z. John Shen;
      Pages: 1727 - 1735
      Abstract: SiC bipolar junction transistor (BJT) still offers an attractive alternative to the more popular SiC MOSFET because of its several advantages, such as low fabrication cost, fast switching speed, and high temperature durability. However, it has not been widely accepted in the market partially because the large constant base current induces large power consumption on its base driver during on-state. In this paper, a new proportional base driver is proposed to provide adaptive base current for SiC BJT and thus minimize its driver power consumption when operating within a wide range of load current and operation temperature in SiC BJT-based power converters. It simply uses a silicon BJT serially connected with a current sensor as a current/temperature-controlled current source in the base driver circuit, promptly supplying adaptive base current for SiC BJT whenever the SiC BJT's junction temperature and/or operation current varies. The operation principle of this proportional base driver is theoretically analyzed and then experimentally verified in a 600-V/20-A SiC BJT-based dc/dc boost converter. Experimental results show that the proposed proportional base driver is capable of driving the SiC BJT much more efficiently than the GeneSiC's constant base driver, greatly reducing the power consumption of base driver by more than 50% over wide ranges of operation currents and temperatures.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Device-Sensor Assembly FEA Modeling to Support Kalman-Filter-Based
           Junction Temperature Monitoring
    • Authors: Alessandro Soldati;Nicola Delmonte;Paolo Cova;Carlo Concari;
      Pages: 1736 - 1747
      Abstract: Junction temperature monitoring for power devices is an essential requirement for high-reliability applications. Temperature sensitive electrical parameters (TSEPs) are powerful tools in this process, but to achieve sufficient accuracy they require complex characterization procedures for each part, that can hardly be implemented in mass-produced converters. This paper proposes a combination of interdisciplinary approaches to ultimately solve this problem for power MOSFETs by an automated procedure that can occur in-place, with devices mounted and without any specific user intervention nor additional heating components. The TSEP exploited in this paper is the ON-state drain-source voltage of the power MOSFET. A wide-bandwidth ON-state voltage sensing circuit and a low-cost thermistor conditioning circuit to sense the case temperature of the device are presented and modeled. A lumped parameters thermal model of the system is given, and finite-element method (FEM) simulations are employed to obtain first-guess values for the unknown thermal network parameters, integrating information from the device datasheet. Finally, an observer based on the Kalman filter applied to the data collected from these sources is presented and evaluated experimentally. Performance is assessed with the use of thermal imaging techniques.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A Thyristor-Based DC Fault Current Limiter With Inductor
           Inserting–Bypassing Capability
    • Authors: Jianzhong Xu;Xibei Zhao;Naizheng Han;Jun Liang;Chengyong Zhao;
      Pages: 1748 - 1757
      Abstract: DC fault current limiters (FCLs) are becoming increasingly important for the prompt dc fault clearance of modular multilevel converter (MMC)-based high-voltage direct current (HVdc) grids. This paper proposes a hybrid FCL topology, in which the main current limiting circuit is composed of thyristors, capacitors, and an inductor. Detailed theoretical analysis of the current limiting processes was carried out to check the electrical stresses. The relationship between the voltage stress and the current limiting time was analyzed, and then a design method for the FCL parameters was provided. An effective method for fast bypassing the FCL inductor was proposed to reduce the energy dissipation when fault current is interrupted by a dc circuit breaker (DCCB). The dynamic performance of the proposed approach has shown that the proposed FCL can effectively limit the rate of rising of the dc fault current and reduce the energy dissipation.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • The Enhanced DC Fault Current Calculation Method of MMC-HVDC Grid With
           FCLs
    • Authors: Jianzhong Xu;Sicheng Zhu;Chengyu Li;Chengyong Zhao;
      Pages: 1758 - 1767
      Abstract: This paper introduces an enhanced dc fault current calculation method for modular multilevel converter-based high-voltage dc (HVdc) grid. The new method considers the fast switching of the fault current limiters (FCLs) and the nonlinear characteristics of the metal-oxide arresters (MOAs). The two peak-valley points of inflection in the dc fault current curves resulting from the insertion of the inductors and the energy dissipation in the MOAs are discussed. The two points are selected as important indicators in the design of the coordinated protection scheme and switching logics. Then, the impact of the total dc reactance distribution in the dc reactor and the FCL reactor, and the initial inductor current values on these two points are analyzed. Finally, the complete fault current calculation method including the action of dc circuit breakers is proposed. The method is validated by electromagnetic transient simulations and has shown good applicability on both the overhead line-based and cable-based HVdc grids.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Impact of Cooling System Capacity on Lifetime of Power Module in
           Adjustable Speed Drives
    • Authors: Ui-Min Choi;Søren Jørgensen;Frede Blaabjerg;
      Pages: 1768 - 1776
      Abstract: In this paper, the impact of the cooling system capacity on the reliability of power modules in power converters is studied. Since the different cooling system capacities lead to different absolute junction temperatures under the same mission profile (MP) of power converters, the lifetimes of the insulatedgate bipolar transistor (IGBT) modules under different mean junction temperatures are assessed by means of an advanced power cycler. Then, the mean junction temperature dependent lifetime factor is modeled based on 18 power cycling test results using Weibull analysis. Finally, the influence of the cooling system capacity on the reliability of the power module is validated by performing a case study of the motor drive system, where the lifetime of the IGBT module is estimated and compared under the two MPs with different average heat-sink temperatures. This study shows the importance of the cooling system capacity not only with respect to the overstress failure of the power device but also with respect to the wear-out failure of the power module and also proposes a method to select the proper heat-sink temperature in order to achieve specified reliability.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Thermal Optimization of Modular Multilevel Converters With Surplus
           Submodule Active-Bypass Plus Neutral-Point-Shift Scheme Under Unbalanced
           Grid Conditions
    • Authors: Wuhua Li;Heya Yang;Jing Sheng;Chushan Li;Min Chen;Xiangning He;Xiaowei Gu;
      Pages: 1777 - 1788
      Abstract: The thermal design of highly reliable modular multilevel converters (MMCs) is significant for the voltage-source converter based high-voltage direct current (VSC-HVdc) systems, especially under the ac unbalanced fault. In this paper, the surplus submodule is employed as new control freedom to optimize the thermal behavior of the MMCs, because its number is linearly increased with the ac voltage dip. With the surplus submodule active bypassed (SSAB), the total submodules of the MMC in one arm can be taken turns to reduce the thermal stress of the hottest power device. In order to obtain equal ac voltages in three phases to improve the SSAB strategy, the neutral-point-shift (NPS) scheme is introduced under the unbalanced conditions, especially single-phase-to-ground fault. Through the balancing of the amplitude of the MMC ac voltages with the NPS scheme, the thermal stress asymmetry of theMMC under the single-phaseto-ground fault is mitigated, and the junction temperature of the most stressed power devices is significantly reduced. Finally, the simulation and experiment results show that the junction temperature rise of the most stressed power device is reduced by nearly 30% with the SSAB plus NPS scheme.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • High Frequency Conducted EMI Investigation on Packaging and Modulation for
           a SiC-Based High Frequency Converter
    • Authors: Yue Xie;Cai Chen;Zhizhao Huang;Teng Liu;Yong Kang;Fang Luo;
      Pages: 1789 - 1804
      Abstract: Silicon carbide (SiC) devices have the advantages of high switching speed and high switching frequency, which can increase the power density, but electromagnetic interference (EMI) will increase along with higher switching frequency thus it can become a challenge for high-frequency converters. In order to clarify the influence factors of EMI noise in SiC converters and find the suppressing method, this paper investigated the conducted EMI in SiC-based high power density electronic systems from two aspects: packaging structures and modulation methods. For packaging investigation, this paper introduced parasitic parameters of power module into EMI analytical model, then defined transfer functions of EMI noise to analyze the influence of parasitic parameters on noise propagation path and further studied the impact of parasitic parameters on noise source by analyzing switching transient and frequency spectrum. Analysis and simulation are carried out based on a hybrid structure SiC power module and discrete SiC devices to verify the analysis. The influence of modulation on EMI is studied by analyzing and comparing two modulations: continuous current modulation (CCM) and triangle current modulation (TCM). To certify the analysis study, two 1.6-kW, 300-kHz switchingfrequency synchronous buck converters are designed and tested. One is based on the hybrid packaging power module and the other is based on TO-247 packaged SiC devices, respectively. The result shows that the hybrid packaging module can suppress the common mode (CM) EMI by 10 dB, and has a suppression on differential mode (DM) EMI between 10 and 20 MHz. Moreover, TCM can increase DM EMI in low-frequency range but suppress it in the high-frequency range.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Conditions for Direct Applicability of Electronic Capacitors to Dual-Stage
           Grid-Connected Power Conversion Systems
    • Authors: A. Mutovkin;M. Mellincovsky;V. Yuhimenko;S. Schacham;A. Kuperman;
      Pages: 1805 - 1814
      Abstract: Active capacitance reduction circuits (ACRCs) are dc-dc converters, terminated by a small auxiliary capacitor, typically utilized to replace bulk electrolytic capacitors in dual-stage grid-connected power conversion systems. Electronic capacitors are ACRCs supporting “plug-and-play” operation in addition to the ability to emulate virtually any finite capacitance at dc-link connected terminals. Despite excellent steady-state functionality, all ACRCs possess the poor response to steplike no-load-to-fullload (and vice versa) transients due to the fact that the auxiliary capacitor utilized (and thus corresponding energy stored) is much smaller than the bulk dc-link capacitor being replaced. Nevertheless, in grid-feeding applications where fuel cells of photovoltaic generators act as a power source, the rate of generated power change is limited. This is also true regarding some off-grid systems such as LED lighting with dimming, where sudden load changes are unnecessary and electronic capacitors seem to be directly applicable in such systems. Therefore, this paper reveals the limits of steplike and ramplike load variations, tolerable by a system equipped with an electronic capacitor, based on its power rating and auxiliary capacitance value utilized. Examples are given for typical systems with 400-V dc link, connected to 50-Hz mains. The validity of presented findings is well-supported by simulations and experiments.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Device Loading and Reliability Analysis of Modular Multilevel Converters
           With Circulating Current Control and Common-Mode Voltage Injection
    • Authors: Deepak Ronanki;Sheldon S. Williamson;
      Pages: 1815 - 1823
      Abstract: The submodule (SM) capacitor voltage ripple and circulating current (CC) are major technical challenges in modular multilevel converters (MMCs). The generation of CC in the MMC results in an increase of SM capacitor voltage ripple, voltage/current stress on power switching devices, and power losses. Therefore, minimizing the CC and SM capacitor voltage ripple is essential for the smooth operation of an MMC. Prior studies and research have focused on different control strategies and modulation schemes to minimize the CC and SM capacitor voltage ripple. This paper presents an impact of active CC control and common-mode voltage (CMV) injection on thermal loading of power switching devices. To evaluate the performance comparison between different control approaches, a generalized control framework for MMC is established. An electrothermal simulation is performed to study the thermal loading on power switching devices. The efficacy of the generalized control scheme is evaluated through PLECS simulations and hardware-in-the-loop experiments. Finally, the thermal loading and reliability of MMCs are evaluated for different modulation schemes with the active CC control and CMV injection.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Variable-Frequency Control Strategy of Isolated Buck–Boost
           Converter
    • Authors: Yan Li;Fang Li;Fangwei Zhao;Xiaojie You;
      Pages: 1824 - 1836
      Abstract: A control strategy with three control variables that contain switching frequency and two duty cycle ratios for an isolated buck-boost converter is proposed in this paper. The converter only operates in the discontinuous current mode (DCM) and the boundary current mode (BCM) in the whole voltage range and load range which can achieve an excellent softswitching performance, a low energy circulation, and a high efficiency. On the basis of the operational principle and variables simplification, the optimal operating point that has a minimum clamped inductor peak current value is obtained. Under the variable-frequency control strategy, the converter characteristics are analyzed, such as the direct energy transfer time ratio, peak current value of the clamped inductor, and switching frequency. Moreover, the implementation of the closed-loop variable-frequency control strategy is given with three operational modes: variable-frequency BCM mode, constant-frequency BCM mode, and variable-frequency DCM mode. A 380-V 1-kW output prototype is fabricated, and the experimental results indicate that high efficiency over overall load range has been achieved under the variable-frequency control strategy due to the excellent soft-switching performance in the whole range. What is more, a smooth transition between three operational modes is achieved.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Virtual Variable Sampling Repetitive Control of Single-Phase DC/AC PWM
           Converters
    • Authors: Zhichao Liu;Bin Zhang;Keliang Zhou;Yongheng Yang;Jingcheng Wang;
      Pages: 1837 - 1845
      Abstract: Repetitive control (RC) presents an attractive solution to achieve low steady-state tracking error and total harmonic distortion for periodic signals. For the conventional RC (CRC), it requires the ratio of the reference signal period to the fixed sampling period to be an integer. Therefore, the reference signal with a variable frequency or a fractional period ratio will lead to severe performance degradation. Although existing hardware variable sampling (VS) rate methods enable the CRC to be frequency adaptive, the VS frequency will also influence the overall system stability, and they need that the CPU has the VS frequency ability. In this paper, a flexible and easy-to-implement method, virtual VS (VVS), is proposed to enable the RC to be frequency adaptive. The proposed VVS method that creates a virtual delay unit to approximate each VS delay achieves a flexible VS as similar to the hardware-based VS but it does not influence the overall system sampling frequency and stability. Experimental results of a single-phase dc/ac converter system are presented to demonstrate the effectiveness of the proposed VVS-RC.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • High-Gain-Integrated Switched Capacitor Indirect Matrix Converter
    • Authors: M. Raghuram;Avneet K. Chauhan;Santosh Kumar Singh;
      Pages: 1846 - 1853
      Abstract: An ultrasparse matrix converter (USMC) is a derived form of an indirect matrix converter having a less number of switches. Even though it has unidirectional power flow capability, it is a quite appropriate candidate for specific applications, such as wind-energy systems, electrohydrostatic actuators, variable speed drives, and so on. However, the gain of the converter is still limited irrespective of various topological and control strategy modifications. Unlike the previous propositions, this paper is primarily focused on the integration of a switched capacitor boost network within the USMC to enhance gain, by preserving the advantages of the USMC. For controlling the proposed converter, a modified space vector modulation technique is also presented in this paper. In order to explore the potential of the proposed converter, analytical expressions are derived. The theoretical findings are further verified using simulation and experimental results.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Analysis of Scalar PWM Approach With Optimal Common-Mode Voltage Reduction
           Technique for Five-Phase Inverters
    • Authors: Sherif M. Dabour;Ayman S. Abdel-Khalik;Ahmed M. Massoud;Shehab Ahmed;
      Pages: 1854 - 1871
      Abstract: Research on common-mode-voltage (CMV) reduction in multiphase drive systems has recently met an intensified interest in the available literature. This paper first explores two existing space-vector-based CMV reduction (CMVR) schemes for five-phase voltage source inverters, represented as CMVR1 and CMVR2, which reduce the CMV by 40% and 80%, respectively. Moreover, a new space-vector-based CMVR scheme, termed as CMVR3, is proposed that not only minimizes the CMV but also reduces the overall switching losses when compared with the other schemes. The optimal duty cycles and the switching sequence of all schemes are introduced. Since the implementation of space-vector-based schemes using look-up tables is a relatively complex and time-consuming process, this paper proposes a simpler scalar PWM approach. This approach can easily be implemented using embedded PWM modules of most commercial digital signal processors. To evaluate the performance of the presented CMVR schemes, a detailed evaluation study is presented. The optimal CMVR scheme over the full modulation index range is also highlighted. The theoretical findings are verified using a prototype five-phase induction machine through simulations and experimentally.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Disturbance Compensation-Based Model Predictive Flux Control of SPMSM With
           Optimal Duty Cycle
    • Authors: Liming Yan;Manfeng Dou;Zhiguang Hua;
      Pages: 1872 - 1882
      Abstract: Finite control set model predictive torque control (FCS-MPTC) is receiving more attention for electric drives, due to its intuitive idea, flexibility to incorporate constrains, and fast torque dynamic response. However, traditional FCS-MPTC requires heavy computation effort and has high torque ripple at steady state. The weighting factors of the cost function are hard to optimize to obtain desired performances. Moreover, torque tracking error exists because FCS-MPTC belongs to the open-loop control strategy. This paper proposes disturbance compensation-based model predictive flux control (DCB-MPFC) with optimal duty cycle (ODC) of surface permanent magnet synchronous motor (SPMSM). This paper first proves the uniformity of MPTC, MPFC, and model predictive voltage control (MPVC). The cost function based on the stator flux linkage vector can be converted to the equivalent cost function based on voltage vector. The role of the equivalent cost function is to compare the deadbeat vector with three pairs of vectors, which can reduce computation effort and torque ripple. In addition, the disturbance compensation strategy is proposed to eliminate torque tracking error. The proposed DCBMPFC is verified effectively by experiments that are compared with traditional algorithm, proportional-integral speed loopbased mode predictive torque control (PI-MPTC).
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A High-Power-Density Power Factor Correction Front End Based on
           Seven-Level Flying Capacitor Multilevel Converter
    • Authors: Shibin Qin;Yutian Lei;Zichao Ye;Derek Chou;Robert C. N. Pilawa-Podgurski;
      Pages: 1883 - 1898
      Abstract: This paper presents a power factor correction (PFC) front end based on a seven-level flying capacitor multilevel (FCML) boost converter. Compared to the conventional two-level boost converter, the proposed seven-level FCML converter features the use of low-voltage-rated transistors, reduced voltage stress, and high effective switching frequency on the filter inductor. These characteristics of the FCML converter lead to drastic reduction in the filter inductor size while maintaining high efficiency and, therefore, significantly improve the power density of the PFC front end compared to conventional solutions. On the other hand, the small inductance imposes challenges on the PFC control. The dynamics of the seven-level FCML converter has been analyzed, and a feedforward control has been implemented to overcome these challenges. A hardware prototype is designed for universal ac input (90 to 265 Vac), 400-V dc output, and 1.5-kW power rating. Compared to existing solutions, the hardware prototype demonstrates improved efficiency and power density while maintaining high power factor and low THD. A power density of 219 W/in3 (490 W/in3 for the power stage) has been achieved, and a peak efficiency of 99.07% has been experimentally verified.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • An EMF Observer for PMSM Sensorless Drives Adaptive to Stator Resistance
           and Rotor Flux Linkage
    • Authors: Tong Wang;Jin Huang;Ming Ye;Jiahao Chen;Wubin Kong;Min Kang;Mingfei Yu;
      Pages: 1899 - 1913
      Abstract: The electromotive force (EMF) observer-based sensorless algorithms are sensitive to temperature rise because it requires the stator resistance (Rs) or the rotor flux linkage (ψr). The temperature measuring of an operating motor can be difficult, therefore, adaptive sensorless algorithms with online Rs and ψr estimation are appreciated. However, existing methods require extra signal injections, transient operations or estimate Rs and ψr one at a time to overcome the rank-deficient problem. In this paper, an adaptive EMF observer which is able to estimate both Rs and ψr simultaneously without requiring any signal injections or transient operations is proposed. The method exploits the harmonic back EMFs (HBEMF) to serve as a novel reference model and regulates the Rs value in the EMF observer accordingly. The rank deficient problem is solved with the extra information provided by the HBEMFs. To make use of the HBEMFs, a parameter insensitive extraction method and an algorithm to calculate the rotor position from them are proposed. With the proposed reference model, an adaptive scheme to regulate Rs is proposed. To obtain the rotor flux linkage, a ψr estimator is also developed. The effectiveness of these proposed methods is verified with experiments and simulations.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Highly Flexible High-Efficiency Multiple-Resonant Wireless Power Transfer
           System Using a Controllable Inductor
    • Authors: Daniel Thenathayalan;Joung-Hu Park;
      Pages: 1914 - 1930
      Abstract: LowQ resonant converter, such as series-series resonant converter, series resonant converter, and parallel resonant converter (PRC), are highly flexible and highly tolerant to coil misalignments. However, these kinds of topologies cannot be employed to the wide air-gap, low-coupling transformers because of their inadequate magnetizing inductance. On the other hand, highQ multiple-resonant converters such as series-PRC) and series-SPRC are very suitable for low-coupling compact wireless transformer applications. However, because these multiresonant topologies have several resonant pairs resonating at a single frequency, these parameter values ought to be consistent throughout the operating conditions to resonate at the same frequency. However, since the wireless power transfer (WPT) applications are required to be flexible and convenient to the customers, the wireless transformers are not supposed to be rigid and stationary. To solve the problem, a controllable inductor for a highQ multiresonant WPT system is proposed to extend the soft switching region and to keep the resonant circulating energy minimum even at resonant mismatch conditions caused by the misalignments or temperature variations of the wireless transformer coils. The performance enhancement of the multipleresonant wireless converter is validated using the proposed controllable inductor technique, and also the feasibility of the proposed technique is proven under different mismatch conditions through 200-W hardware experimental results.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Crosstalk Analysis and Suppression for a Closed-Loop Active IGBT Gate
           Driver
    • Authors: Lu Shu;Junming Zhang;Shuai Shao;
      Pages: 1931 - 1940
      Abstract: This paper analyzes the crosstalk issues for a closed-loop active insulated gate bipolar transistor (IGBT) gate driver (AGD) based on di/dt and dv/dt detection and presents a crosstalk suppression (CTS) circuit. Closed-loop active gate drivers for IGBTs are beneficial in switching transient control by generating extra gate control signals to regulate the gate drive voltage or current with di/dt and dv/dt feedback. AGDs achieve the compensation of the IGBT nonlinearities and are independent of operating points. In a phase-leg configuration, however, AGDs produce additional crosstalk interference besides that due to reverse transfer capacitance. These two kinds of crosstalk interferences together lead to an oscillation in the IGBT gate voltage, and then a shoot-through fault may occur. An equivalent circuit model of the feedback circuit is presented to analyze and evaluate the crosstalk issues. The design and realization of a CTS circuit are presented to eliminate the crosstalk and extra gate drive losses caused by crosstalk. The experimental results substantiate the validity of the theoretical crosstalk analysis and the effectiveness of the proposed CTS circuit.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A Novel High-Step-Up Coupled-Inductor DC–DC Converter With Reduced Power
           Device Voltage Stress
    • Authors: Hongchen Liu;Junxiong Wang;Yuliang Ji;
      Pages: 1941 - 1948
      Abstract: In this paper, a novel high-step-up coupled-inductor dc-dc converter is presented. The proposed converter has an excellent feature, i.e., the closer the turn ratio to 1, the higher the gain of the converter, also the lower the voltage stress of the switch. Duty cycle and the turn ratio of the coupled inductor together determine the voltage gain of the converter; thus, it can achieve any wanted voltage without the circuit to operate at the extreme duty cycle. In addition, the proposed converter can realize higher voltage gain with a small duty cycle. And it is suitable for many types of new energy source, especially photovoltaic generation systems, which has a common ground and a continuous input current switch with great benefits for the life of the input power supply. The power density of the system improves for the lack of isolation transformer. Due to the introduction of the clamp circuit, the voltage spikes across the switch are limited. Therefore, we can choose a switch with lower voltage levels that would cut costs and reduce conduction losses. As the energy of leakage energy is absorbed by the circuit, the efficiency is further improved. The operational principle and the steady-state analysis of the proposed converter are presented in this paper. Finally, the experiment with an input 48-V voltage and an output voltage of 380 V is implemented, verifying the validity of this paper.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Advanced Single-Phase Nine-Level Converter for the Integration of
           Multiterminal DC Supplies
    • Authors: Ahmed I. M. Ali;Mahmoud A. Sayed;Essam E. M. Mohamed;Ahmed M. Azmy;
      Pages: 1949 - 1958
      Abstract: This paper presents a new symmetrical single-phase nine-level dc-ac converter for the applications of distributed generation systems. The proposed multilevel inverter (MLI) utilizes four independent dc sources to generate the nine output voltage levels considering a reduced number of switching devices. The proposed inverter consists of main and auxiliary circuits. The main circuit is a single H-bridge circuit, which is responsible for output voltage polarity. The auxiliary circuit consists of a special combination of switching devices, which are used to synthesize the multilevel output voltage. The merits of the proposed MLI are: increased output voltage levels at reduced number of switching devices, low switching loss, low total harmonic distortion, low dv/dt stress on the switches, and hence, low ratings of the switching devices, and low cost. The effectiveness of the proposed MLI and its pulsewidth modulation switching pattern has been verified experimentally by using a laboratory prototype controlled by DSPACE-1103.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Interlinking Converter to Improve Power Quality in Hybrid AC–DC
           Microgrids With Nonlinear Loads
    • Authors: Dang-Minh Phan;Hong-Hee Lee;
      Pages: 1959 - 1968
      Abstract: To exploit the advancements of both ac and dc microgrids (MGs), hybrid ac-dc MGs (HMGs) have been considered. An interlinking converter (IC) is typically used to connect dc and ac MGs. In HMGs, the power quality is severely affected when nonlinear loads are connected to an ac bus. We developed an effective control scheme for the IC to maintain a sinusoidal point of common coupling (PCC) voltage under nonlinear load conditions in islanded HMGs. In the proposed control scheme, the IC controls the PCC voltage by providing harmonic currents caused by the nonlinear load as well as the active power sharing between dc distributed generation (DG) and ac DG. The system stability and controller design process were analyzed. Each power converter in the HMGs is controlled independently without a communication link, and the desired IC current is indirectly determined by considering the IC terminal voltage instead of the load current. Therefore, the control system can be implemented very easily with reduced cost. The performance of the proposed IC control scheme was verified by a simulation and experiment.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Multilevel Torque Hysteresis-Band Based Direct-Torque Control Strategy for
           a Three-Level Open-End Winding Induction Motor Drive for Electric Vehicle
           Applications
    • Authors: Suresh Lakhimsetty;Venkata Siva Prasad Satelli;Rajendra Singh Rathore;V. T. Somasekhar;
      Pages: 1969 - 1981
      Abstract: The number of levels present in the torquehysteresis controller influence the performance of the direct torque controlled (DTC) induction motor drives. In this paper, the effects of the number of levels in the torque-hysteresis-band controllers (THBCs) on the performance of the conventional DTC-based three-level open-end winding induction motor drives are reported. A power-loss evaluation model was employed to investigate the influence of the number of levels present in THBC on the switching and conduction losses occurring in the dualinverter system. The performance indices considered in this paper are: 1) the flux-ripple; 2) the torque ripple; and 3) the total power loss in the dual-inverter system. Furthermore, these performance indices are evaluated with a newly emerging control strategy, namely, the predictive torque control, and are compared with those obtained with the DTC. The simulation results are validated by showing the experimental results.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Optimum Design of Decoupled Concentric Coils for Operation in
           Double-Receiver Wireless Power Transfer Systems
    • Authors: Ujjwal Pratik;Benny J. Varghese;Ahmed Azad;Zeljko Pantic;
      Pages: 1982 - 1998
      Abstract: Wireless power transfer is becoming ubiquitous in consumer electronics and electrified transportation, providing a convenient method to supply power or charge various devices, such as cell phones, watches, laptops, electric vehicles, and so on. Delivering power from one transmitter unit to more than one receiver can save space and reduce the cost of the overall system. For applications where the sizes of transmitter and receiver units are commeasurable, a frequently used design is the one with carefully overlapped D-shaped coils (also named bipolar pad) to achieve decoupling between coils. In this paper, an alternative optimized design of two concentric decoupled coils is proposed. The design allows the receiver coils to operate at close proximity, collecting power from a shared magnetic field generated by a single transmitter pad. The design methodology is based on a bucking coil layout where the coils' decoupling is achieved by means of flux cancellation caused by alternating the winding direction of turns in one of the coils. Apart from eliminating coupling between the two receivers, the proposed design maximizes the coupling between the transmitter and the second receiver coil and consequently increases the power transfer capability, offering the equivalent coupling coefficient similar to or better than a pair of bipolar DD coils. Finally, the number and space between turns are selected to improve the quality factor of the proposed receiver. The proposed solution is designable analytically and the second receiver can be added even after the first receiver is already built. Moreover, the proposed design demonstrates superior misalignment tolerance, particularly in the lateral direction, compared to other decoupled coil designs. The proposed methodology is validated through simulations and experimental tests and has proved to be accurate and easy for implementation.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Three-Phase Capacitor Clamped Boost Inverter
    • Authors: Dogga Raveendhra;Mukesh K. Pathak;
      Pages: 1999 - 2011
      Abstract: This paper introduces a new capacitor clamped three-phase dc-ac converter with an intrinsic step-up abilities by utilizing small passive components. This proposed inverter has several unique features, such as: 1) lower number of components' count; 2) high dc-ac gain; 3) reduced voltage stresses on the capacitor; 4) offers better power quality (very low voltage and current total harmonic distortions) without any ac-side filter; and 5) reduced voltage stress on power semiconductor devices. Reduced voltage stress on capacitors leads to better reliability and enhanced lifespan of the inverter. The analysis of the proposed inverter is completed with the help of a mathematical model and state-space averaging model. This inverter performance under different test conditions is compared with the boost converter fed voltage source inverter, Z-source inverter (ZSI), quasi-ZSI (qZSI), switched boost inverter, improved ZSI, switched inductorZSI, diode-Assisted qZSI, capacitor-assisted qZSI, and extended boost ZSI; MATLAB Simulink results demonstrated that the proposed inverter capabilities are superior to the above-mentioned topologies. A 1200-W experimental prototype has been built to validate the feasibility and benefits of the system. The simulation and experimental results reveal that the proposed inverter offers better power quality, reliability, and high lifetime.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A New Nonisolated Quasi-Z-Source Inverter With High Voltage Gain
    • Authors: Xiaoquan Zhu;Bo Zhang;Dongyuan Qiu;
      Pages: 2012 - 2028
      Abstract: This paper proposes a new high-boost quasi-Zsource inverter (qZSI) with combined two quasi-Z-source networks, which has a common ground between the input source and the inverter bridge. Compared with other noncoupled inductorbased (q)ZSIs, by using the same total number of passive and active components, the proposed inverter provides higher boost capability, requires smaller inductance and capacitance values at the impedance network, achieves lower voltage stress across the active switching devices, and has higher modulation index for the inverter bridge to improve the output waveform quality. Although the proposed inverter has the same voltage boost factor with the enhanced boost (q)ZSIs (EB-ZSI) and EB-qZSIs, the proposed scheme has lower capacitor voltage stress than EB-ZSI and has higher efficiency than EB-qZSI. The topological configuration, operating principles, power loss analysis, and performance comparison with other high-boost (q)ZSIs are presented. Finally, both simulations and experimental results are given to validate the aforementioned characteristics of the proposed topology.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Adaptive Passivity-Based Control of dc–dc Buck Power Converter With
           Constant Power Load in DC Microgrid Systems
    • Authors: Mustafa Alrayah Hassan;Er-ping Li;Xue Li;Tianhang Li;Chenyang Duan;Song Chi;
      Pages: 2029 - 2040
      Abstract: This paper presents a robust nonlinear control strategy to solve the instability problem of dc-dc buck power converter with a constant power load in dc microgrid systems. Based on the passivity-based control (PBC), a nonlinear disturbance observer (NDO) is designed to improve the control robustness against both load and line variations, whereas the PBC guarantees the system stability due to its property of transient energy dissipation. By applying the disturbance estimation technique, NDO works in parallel with the PBC controller to compensate the disturbances through a feed-forward channel. This strategy ensures large signal stability as well as fast recovery performance of the system during disturbance/uncertainty as compared to other nonlinear control methods. Hardware-in-loop (HIL) experiment is performed on an OPAL-RT real-time simulator. MATLAB simulation and HIL results are provided to verify the proposed control strategy. Further validations are presented using a real hardware experiment to emphasize the robustness of the proposed controller.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A High-Performance Dynamic Controller For an Active Power Decoupler With
           AC-Side Storage Element
    • Authors: Sujata Bhowmick;Loganathan Umanand;
      Pages: 2041 - 2056
      Abstract: The instantaneous power in a single-phase system pulsates at double the supply frequency. With the effective use of the storage element, the electrolytic capacitor placed at the dc bus can be replaced by film capacitors, thereby improving the converter lifespan. Active power decoupling (APD) using an extra set of switches aims to attain the same. Recently, a promising APD topology has been reported, offering a lesser number of switches, as well as lesser stress on the switches for a wide range of power factor. However, the control of that converter poses a challenge as it has more number of states than the independent control variables. This paper focuses on the control aspect of the topology. It is shown that controlling two out of three states guarantees the overall system performance at the steady state. Also, ripple power in the dc bus is controlled in a closed-loop fashion so as to handle model uncertainty and thereby improve the steady-state performance. Furthermore, the solution to suppress the harmonic power, reflected on to the dc bus, under polluted grid condition is provided. The simulation and experimental results are presented supporting the analysis and design of the controller structure.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Overcurrent and its Restraining Method of PQ-Controlled Three-Phase
           Four-Wire Converter Under Asymmetrical Grid Fault
    • Authors: Zhikang Shuai;Min Xiao;Jun Ge;Z. John Shen;
      Pages: 2057 - 2069
      Abstract: Three-phase four-wire converter can eliminate power oscillation by introducing the zero sequence current, but the output unbalanced currents are likely to cause overcurrent problem under asymmetrical grid fault. This paper investigates the fault current characteristics of PQ-controlled three-phase four-wire converter and proposes a new overcurrent protection method based on the maximum phase current amplitude estimation. First, the expression of the reference current with active and reactive power oscillation suppression is formulated by the instantaneous reactive power theory. Second, amplitudes of the three-phase unbalanced currents are calculated. The relationships between amplitudes and grid voltage drop depth, as well as that between amplitudes and power factor, are analyzed, respectively. Finally, the reference currents which could simultaneously suppress the fault overcurrent and power oscillation are regulated by detecting the fault phase of power grid and estimating the maximum phase current amplitude. Since the maximum phase current amplitude is obtained by only one phase, the calculation process can be very simplified. RT-LAB experimental results verify the validity of the theoretical analysis by comparisons with the existing methods.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • An Isolated Bidirectional Single-Stage Inverter Without Electrolytic
           Capacitor for Energy Storage Systems
    • Authors: Amir Mousa Haddadi;Shahrokh Farhangi;Frede Blaabjerg;
      Pages: 2070 - 2080
      Abstract: This paper presents a new isolated bidirectional single-stage inverter (IBSSI) suitable for grid-connected energy storage systems. The IBSSI contains no electrolytic capacitor. Therefore, its reliability and lifetime are improved in comparison with the well-known two-stage voltage source inverters without increasing the converter cost. In the IBSSI, a high-frequency transformer (HFT) is used to isolate the energy storage device from the grid. In addition, an active snubber is used to suppress the voltage spikes caused by the leakage inductance of the HFT and improve the converter efficiency. Boosting capability with a high-voltage ratio is also provided by the IBSSI. In this paper, a novel switching algorithm based on the space vector modulation is developed to maintain the volt-second balance on the HFT and generate three-phase balanced currents. The switching algorithm also provides soft switching conditions for the main switches, which are explained in this paper. Moreover, a single-loop control system is employed to regulate the input and output currents. The test results of the 3-kW prototype with the SiC power devices show that the IBSSI can inject/draw three-phase currents to/from the grid with a unity power factor and without using any ac current sensors in the discharging/charging mode.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Nonlinear Model Predictive Speed Control of Electric Vehicles Represented
           by Linear Parameter Varying Models With Bias Terms
    • Authors: Navid Vafamand;Mohammad Mehdi Arefi;Mohammad Hassan Khooban;Tomislav Dragičević;Frede Blaabjerg;
      Pages: 2081 - 2089
      Abstract: This paper investigates a novel approach to design a nonlinear optimal model predictive controller for the speed control of constrained nonlinear electric vehicles (EVs). The proposed approach employs a linear parameter varying model including bias terms and a model predictive scheme. The controller design conditions are derived in terms of linear matrix inequalities (LMIs), which can be solved through convex optimization techniques. Due to considering bias terms in the system dynamic, the proposed approach can be regarded as the general case of the existing results. Furthermore, practical limitations on the amplitude of the input signal are considered and formulated in terms of LMIs. An EV dynamic with bias term is presented and hardware-in-the-loop real time and experiments are carried out to illustrate the effectiveness and merits of the proposed approach over the existing results.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • A Novel Control Technique to Reduce the Effects of Torsional Interaction
           in Wind Turbine System
    • Authors: Jishnu Kavil Kambrath;Md Shafquat Ullah Khan;Youyi Wang;Ali I. Maswood;Yong-Jin Yoon;
      Pages: 2090 - 2105
      Abstract: Though power electronic interface is prone to higher failure in wind turbine system (WTS), the failure downtime due to mechanical and generator malfunctioning is highest. Unforeseen electromechanical interactions caused due to dynamic load variation and transient torsional stress is a major cause for failures in the drive-train and generator in WTS. In the literature, several techniques, such as generator speed feedback, stress damping controller, and virtual inertia damping controller, have been proposed in regards to the problem stated. Though the techniques are promising, the factor of independent control of natural frequency and damping ratio has not been considered. This paper proposes speed difference damping controller (SDDC), which is a novel and improved control technique that decouples the two above-mentioned parameters and improves the electromechanical performance significantly, reducing the torsional vibration of the driveline. The controller gains are designed based on the derived two-inertia system model that is used to represent the first natural frequency torsional vibration. In this paper, theoretical analysis and control design of SDDC are articulately addressed. A detailed comparative study of SDDC is carried out with respect to the other proposed controllers. The modeled WTS is examined for the first torsional natural frequency under two extreme wind-input conditions, i.e., sinusoidal wind condition, wind impulse, and grid dynamic, and one real-wind test case scenario. For the experimental verification, a multimass test rig operating at the critical speed and dynamic impulse load variation is analyzed in parts.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Characteristics Analysis of Capacitor Voltage Ripples and Dimensioning of
           Full-Bridge MMC With Zero Sequence Voltage Injection
    • Authors: Cong Zhao;Zhe Wang;Zixin Li;Ping Wang;Yaohua Li;
      Pages: 2106 - 2115
      Abstract: Compared to the conventional half-bridge submodule-based modular multilevel converter (MMC), the full-bridge submodule (FBSM) capacitance of FB-MMC can be reduced significantly with consideration of negative voltage state of the FBSM, which has benefits to cost and size reduction. This paper analyzes the characteristics of the FBSM voltage fundamental frequency and second-order harmonic fluctuations of the FB-MMC without and with zero sequence voltage injection (ZSVI) comparatively. The analyses show that ZSVI has almost no impacts on the FBSM voltage fundamental frequency fluctuations, while the second-order harmonic components become 5/6 times of the one without. Based on these analyses, with the same fluctuation constraint as the case without ZSVI, the FBSM capacitance dimensioning method is also presented. The correctness of the presented analyses is verified by comparative simulation results on a ±200 kV FB-MMC system and experimental results on a laboratory platform. The simulation and experimental results indicate that the FBSM capacitance of the FB-MMC can achieve a reduction about 10% with ZSVI.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
  • Hybrid Topology of a Diode-Rectifier-Based HVDC System for Offshore Wind
           Farms
    • Authors: Yiran Chang;Xu Cai;
      Pages: 2116 - 2128
      Abstract: This paper proposes a hybrid converter for the high-voltage direct-current (HVDC) transmission of offshore wind farms. The proposed converter consists of a diode rectifier and a paralleled auxiliary modular multilevel converter (MMC). The auxiliary converter is a low-power bidirectional ac/dc converter with a high conversion ratio. During the startup procedure of a wind farm, the auxiliary converter actively sets up the ac voltage of the collection grid and supplies the necessary startup power to the wind turbines. In addition, the auxiliary converter provides the reactive power and partly compensates harmonic currents to the wind farm collection system, so that the hybrid topology can overcome the disadvantages of a diode-rectifier-based HVDC system. After the startup sequence, power delivery is shifted from the auxiliary converter to the diode rectifier by controlling the ac voltages. Compared with HVDC systems based on full-power MMCs, the proposed system significantly decreases the number of submodules, resulting in lower volume, weight, and cost. The effectiveness of the proposed system is verified by the simulation results of a 160-MW offshore wind power system and the experiment results of a 300 W system.
      PubDate: Sept. 2019
      Issue No: Vol. 7, No. 3 (2019)
       
 
 
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