@inproceedings{lee_wang_huang_2015, title={4H-SiC 15kV n-IGBT physics-based sub-circuit model implemented in Simulink/Matlab}, DOI={10.1109/apec.2015.7104478}, abstractNote={A physics-based 15kV 4H-SiC n-IGBT sub-circuit model implemented in Simulink/Matlab is demonstrated in this work. Two-phase voltage ramp during the switching before and after punch through is well predicted. Simulated with a simple 4H-SiC Schottky diode model, the switching results is experimentally verified. The current bump during turn-off and current overshoot during turn-on are well-predicted and can be explained by the instantaneous output capacitances of the IGBT and Schottky diode. The computing speed for the full turn-on and off with stray inductance is approximately 2 minutes.}, booktitle={2015 thirtieth annual ieee applied power electronics conference and exposition (apec 2015)}, author={Lee, M. C. and Wang, G. Y. and Huang, A. Q.}, year={2015}, pages={1051–1057} }
 @inproceedings{song_huang_lee_wang_2015, title={A dynamic measurement method for parasitic capacitances of high voltage SiC MOSFETs}, DOI={10.1109/ecce.2015.7309788}, abstractNote={The voltage dependent parasitic capacitances in high voltage semiconductor power devices such as MOSFET, JFET and IGBT play a vital role in the understanding and modeling of the device switching performance. In this paper, a simple but effective parasitic capacitance measurement method is proposed. The output capacitance Coss and the reverse transfer capacitance Crss can be measured simultaneously and directly in the proposed parasitic capacitance tester (PCT). The input capacitance Ciss is measured based on gate driver waveforms during the turn on transient. To verify the effectiveness of the proposed method, a 10kV SiC MOSFET parasitic capacitances are measured as an example. The measured parasitic capacitance results are compared with those from a conventional LCR meter and theoretical calculation. Furthermore, a Matlab/Simulink compact circuit model for the 10kV SiC MOSFET is developed based on the measured parasitic capacitances, whose results also validate the effectiveness of the proposed method.}, booktitle={2015 ieee energy conversion congress and exposition (ecce)}, author={Song, X. Q. and Huang, A. Q. and Lee, M. J. and Wang, G. Y.}, year={2015}, pages={935–941} }
 @inproceedings{wang_huang_wang_song_ni_ryu_grider_schupbach_palmour_2015, title={Static and dynamic performance characterization and comparison of 15 kV SiC MOSFET and 15 kV SiC n-IGBTs}, DOI={10.1109/ispsd.2015.7123431}, abstractNote={This paper presents the static and dynamic performance of 15 kV SiC IGBTs with 2 um and 5 um field-stop buffer layer thicknesses respectively and compares them with 15 kV SiC MOSFET in term of loss and switching capability. Their switching energy for different gate resistors and temperature have been reported and compared. A 5 kHz 10.5 kW 8 kV boost converter has been built and tested using these three devices respectively. The MOSFET based boost converter has the highest efficiency 99.39% which is the highest reported efficiency for a high voltage SiC device based converter. PLECS loss models can be developed for these devices based on the characterization data to simplify the simulation of a variety circuits or applications which potentially utilize these devices.}, booktitle={Proceedings of the international symposium on power semiconductor}, author={Wang, G. Y. and Huang, A. Q. and Wang, F. and Song, X. Q. and Ni, X. J. and Ryu, S. H. and Grider, D. and Schupbach, M. and Palmour, J.}, year={2015}, pages={229–232} }
 @article{du_wang_wang_huang_2014, title={Modeling of the High-Frequency Rectifier With 10-kV SiC JBS Diodes in High-Voltage Series Resonant Type DC-DC Converters}, volume={29}, ISSN={["1941-0107"]}, DOI={10.1109/tpel.2013.2288642}, abstractNote={The superior material properties of the wide bandgap silicon carbide (SiC) semiconductors enable excellent device characteristics such as low on-resistance, high breakdown voltage, fast switching speed, high temperature operation, etc. 10-kV SiC junction barrier Schottky (JBS) diode prototype made by Cree was characterized in this paper first. The high-voltage (HV) and high-frequency rectifier consisting of SiC JBS diodes in dc-dc converters can potentially benefit from the device characteristics. However, capacitive current in both forward and reverse recovery process is observed due to the junction capacitance when the SiC JBS diode is turned on and off, which increases the reactive power and reduces the rectifier output power and voltage. To better utilize the devices, the rectifier operation is analyzed in consideration of the impact of the JBS diode parasitic capacitance. Two equivalent circuit models, the series and the parallel input impedance model, are proposed. The distributed junction capacitance of JBS diodes is lumped into the equivalent input capacitance such that the input impedance and output voltage, two critical parameters in HV dc-dc converter design, can be predicted from the models. Experiment setup of SiC JBS diode rectifier was built and the test results verified the modeling work.}, number={8}, journal={IEEE TRANSACTIONS ON POWER ELECTRONICS}, author={Du, Yu and Wang, Jun and Wang, Gangyao and Huang, Alex Q.}, year={2014}, month={Aug}, pages={4288–4300} }
 @article{rezaei_wang_huang_cheng_palmour_scozzie_2014, title={Static and Dynamic Performance Evaluation of > 13 kV SiC-ETO and Its Application as A Solid-State Circuit Breaker}, volume={778-780}, ISBN={["*****************"]}, ISSN={["0255-5476"]}, DOI={10.4028/www.scientific.net/msf.778-780.1025}, abstractNote={This study addresses the transient and steady-state performance of a >13 kV SiC ETO as a Solid-State Circuit Breaker (SSCB). The developed SiC-ETO is based on a 1 cm2, 15 kV SiC p-GTO with an extremely low differential resistance. Static performance of the device, including the on-state voltage drop at different temperatures and different currents has been carried out in this paper. Furthermore, transient performance of the device, including the turn off energy of the device has been studied. Also, the superior performance of the p-type SiC-ETO has been exploited to design and implement a solid-state circuit breaker. The studies verify the superiority of the SiC p-ETO compared to other solid state devices for this application.}, journal={SILICON CARBIDE AND RELATED MATERIALS 2013, PTS 1 AND 2}, author={Rezaei, Mohammad Ali and Wang, Gangyao and Huang, Alex Q. and Cheng, Lin and Palmour, John W. and Scozzie, Charles}, year={2014}, pages={1025-+} }
 @inproceedings{rezaei_wang_huang_cheng_scozzie_2014, title={Static and dynamic characterization of a > 13kV SiC p-ETO device}, DOI={10.1109/ispsd.2014.6856049}, abstractNote={This study addresses the transient and steady-state performance of a >13 kV SiC p-ETO. The developed SiC p-ETO is based on a 1 cm2, 15 kV SiC p-GTO with an extremely low differential resistance. Static performance of the device, including the on-state voltage drop at different temperatures and different currents is carried out in this paper. Furthermore, transient performance of the device, including the turn off energy and also the Safe Operating Area (SOA) of the device has been studied. Also, the superior performance of the p-type SiC-ETO has been exploited to design and implement a solid-state circuit breaker. The studies verify the superiority of the SiC pETO compared to other solid state devices for this application.}, booktitle={Proceedings of the international symposium on power semiconductor}, author={Rezaei, M. A. and Wang, G. Y. and Huang, A. Q. and Cheng, L. and Scozzie, C.}, year={2014}, pages={354–357} }
 @article{chen_huang_li_wang_gu_2013, title={Analysis and Comparison of Medium Voltage High Power DC/DC Converters for Offshore Wind Energy Systems}, volume={28}, ISSN={["1941-0107"]}, DOI={10.1109/tpel.2012.2215054}, abstractNote={Offshore wind farm with an internal medium-voltage dc (MVDC)-grid collection connected HVDC transmission may be an option to harvest offshore wind energy. High-power MV dc/dc converters with high-step-up conversion ratios are the key components for the internal MVDC grid. In this paper, a high-efficiency step-up resonant switched-capacitor converter for offshore wind energy system is studied, which is characterized by the soft-switching condition for all switches and diodes. This significantly reduces switching losses and higher switching frequency is feasible to reduce the overall system volume and weight. The comparisons with other two kinds of topologies are also presented; moreover, the possible specification requirements of high power MV dc/dc converters are analyzed and set. The operation principle of the proposed converter has been successfully verified by simulation and experiment results.}, number={4}, journal={IEEE TRANSACTIONS ON POWER ELECTRONICS}, author={Chen, Wu and Huang, Alex Q. and Li, Chushan and Wang, Gangyao and Gu, Wei}, year={2013}, month={Apr}, pages={2014–2023} }
 @inproceedings{wang_wang_magai_lei_huang_das_2013, title={Performance comparison of 1200V 100A SiC MOSFET and 1200V 100A silicon IGBT}, DOI={10.1109/ecce.2013.6647124}, abstractNote={This paper presents the characteristics of the first commercial 1200V 100A SiC MOSFET module and compares it with state-of-the-art silicon IGBT with the same rating. The results show that the 1200V SiC MOSFET has faster switching speed and much lower loss compared with silicon IGBT. Moreover, the silicon IGBT switching loss will increase significantly for higher operation temperature, while the SiC MOSFET switching loss is almost the same for different temperature. A loss model has been implemented in PLECs in order to simulation the losses. An 11kW singlephase inverter prototype with 600V dc bus and 380Vac output voltage has been built for evaluating and comparing the SiC MOSFET and Si IGBT performance. The test results match with the simulation very well and show that with 40 kHz switching frequency the inverter efficiency can be increased to 98.5% from 96.5% if replacing the Si IGBT with the SiC MOSFET module.}, booktitle={2013 ieee energy conversion congress and exposition (ecce)}, author={Wang, G. Y. and Wang, F. and Magai, G. and Lei, Y. and Huang, A. and Das, M.}, year={2013}, pages={3230–3234} }
 @inproceedings{yu_she_ni_wang_huang_2013, title={Power management strategy for DC microgrid interfaced to distribution system based on solid state transformer}, DOI={10.1109/ecce.2013.6647394}, abstractNote={A typical DC microgrid, which can be enabled by Solid State Transformer (SST), is investigated in this paper. One unidirectional DC/DC converter for photovoltaic (PV), one bidirectional DC/DC converters for battery, and a SST based on distribution system level, are included in the proposed DC microgrid system. In order to manage the system operation, a distributed power management strategy is proposed. In the proposed control algorithm, not only the DC microgrid system can interface to the distribution system, but each module in the system can be distributed based on its own characteristics. Experimental results verify that the proposed power management strategy can be applied to a DC microgrid stably and achieve good performance.}, booktitle={2013 ieee energy conversion congress and exposition (ecce)}, author={Yu, X. W. and She, X. and Ni, X. J. and Wang, G. Y. and Huang, A.}, year={2013}, pages={5131–5136} }
 @inproceedings{huang_wang_li_huang_baliga_2013, title={Short-circuit capability of 1200V SiC MOSFET and JFET for fault protection}, DOI={10.1109/apec.2013.6520207}, abstractNote={The short-circuit capability of power switches is crucial for the fault protection. In this paper, 1200V SiC MOSFET and normally-off SiC JFET have been characterized and their short-circuit capabilities have been studied and analyzed at 400V DC bus voltage. Due to different physics in the channels, SiC MOSFET and SiC JFET show different types of temperature coefficient. During the short-circuit operation, the saturation current, Isat, of SiC MOSFET increases for several microseconds before the gentle decreasing while that of SiC JFET decreases drastically from the very beginning. The SiC MOSFETs failed after short-circuit operations of 80μs and 50μs at 10V and 15V gate bias respectively while the SiC JFET could survive a short-circuit time more than 1.4msec.}, booktitle={2013 twenty-eighth annual ieee applied power electronics conference and exposition (apec 2013)}, author={Huang, X. and Wang, G. Y. and Li, Y. S. and Huang, A. Q. and Baliga, B. J.}, year={2013}, pages={197–200} }
 @article{zhao_wang_bhattacharya_huang_2013, title={Voltage and Power Balance Control for a Cascaded H-Bridge Converter-Based Solid-State Transformer}, volume={28}, ISSN={["1941-0107"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84878813627&partnerID=MN8TOARS}, DOI={10.1109/tpel.2012.2216549}, abstractNote={The solid-state transformer (SST) is an interface device between ac distribution grids and dc distribution systems. The SST consists of a cascaded multilevel ac/dc rectifier stage, a dual active bridge (DAB) converter stage with high-frequency transformers to provide a regulated 400-V dc distribution, and an optional dc/ac stage that can be connected to the 400-V dc bus to provide residential 120/240 V $_{\rm ac}$. However, due to dc-link voltage and power unbalance in the cascaded modules, the unbalanced dc-link voltages and power increase the stress of the semiconductor devices and cause overvoltage or overcurrent issues. This paper proposes a new voltage and power balance control for the cascaded H-Bridge converter-based SST. Based on the single-phase dq model, a novel voltage and the power control strategy is proposed to balance the rectifier capacitor voltages and the real power through parallel DAB modules. Furthermore, the intrinsic power constraints of the cascaded H-Bridge voltage balance control are derived and analyzed. With the proposed control methods, the dc-link voltage and the real power through each module can be balanced. The SST switching model simulation and the prototype experiments are presented to verify the performance of the proposed voltage and power balance controller.}, number={4}, journal={IEEE TRANSACTIONS ON POWER ELECTRONICS}, author={Zhao, Tiefu and Wang, Gangyao and Bhattacharya, Subharshish and Huang, Alex Q.}, year={2013}, month={Apr}, pages={1523–1532} }
 @inproceedings{kadavelugu_wang_bhattacharya_huang_2012, title={Auxiliary power supply for Solid State Transformers}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84870892973&partnerID=MN8TOARS}, DOI={10.1109/ecce.2012.6342647}, abstractNote={In contrast to traditional 60 Hz transformer, solid state transformer (SST) offers power flow control, integration of renewables and maintaining grid stability in high renewable penetration scenario. Like a typical power converter, SST requires low voltage (24 V dc) power for its control and sensing circuits. In running condition, this power is derived from its low voltage dc bus at 400 V. But it is challenging to derive it during start-up, because the only source available during start-up is the distribution grid at 7.2 kV, 60 Hz. Due to high input voltage (7.2 kV, 60 Hz), deriving a control supply of about 150 W, even for just start-up duration of about 200 ms, presents a novel power electronics problem. In this paper, two solutions have been proposed to address this issue, by taking a 20 kVA, 6.5 kV Si IGBT and 15 kV SiC MOSFET based SSTs as the reference converters. The first solution is generic and is based on storing the required start-up energy in a dc capacitance. This is based on developing a cost-effective high voltage switch using low voltage IGBTs with self-driven functionality. The second solution, applicable only to SST topologies with high voltage ac capacitive filter, is to tap the energy from the capacitor itself. The fundamental constraints considered for both the solutions are practical feasibility at high voltage (7.2 kV ac or over 10 kV dc), power loss, size, weight and cost-effectiveness. Experimental validation of extracting continuous power for the IGBT gate driver ICs from the snubber is presented with 200 V input. And, the results of the auxiliary power derivation from the filter capacitor are shown with 5.7 kV ac input.}, booktitle={2012 IEEE Energy Conversion Congress and Exposition, ECCE 2012}, author={Kadavelugu, A. and Wang, G. and Bhattacharya, Subhashish and Huang, A.}, year={2012}, pages={1426–1432} }
 @article{she_huang_zhao_wang_2012, title={Coupling Effect Reduction of a Voltage-Balancing Controller in Single-Phase Cascaded Multilevel Converters}, volume={27}, ISSN={["1941-0107"]}, DOI={10.1109/tpel.2012.2186615}, abstractNote={This paper presents a new voltage-balancing controller for cascaded multilevel converters, especially for single-phase cascaded multilevel converters. It proposes a control algorithm that devotes itself not only to balancing the floating dc capacitors but also to eliminating the coupling effect between the voltage-balancing controller and the original system controller (controller without additional voltage-balancing controllers). Specifically, the average model in the d-q coordinate frame is derived and the control law is established. Then, the coupling effect between the voltage-balancing controller and the original system controller is identified and a new expression for duty cycle modification is proposed thus to eliminate the effect. Furthermore, this paper gives the design considerations of the pro- posed method, including the derivation of key transfer functions and effective voltage-balancing area, for the completeness of the discussion. Moreover, the reference generation techniques of the voltage-balancing controller are also discussed. This paper investigates the voltage imbalance in the soft-start process caused by an unsuitable reference, and presents a simple modified reference generation solution. Finally, both simulation and experimental results verify the performance of the proposed control system.}, number={8}, journal={IEEE TRANSACTIONS ON POWER ELECTRONICS}, author={She, Xu and Huang, Alex Q. and Zhao, Tiefu and Wang, Gangyao}, year={2012}, month={Aug}, pages={3530–3543} }
 @inproceedings{wang_huang_wang_she_burgos_2012, title={Feed-forward control of solid state transformer}, DOI={10.1109/apec.2012.6165964}, abstractNote={The solid state transformer (SST) can be viewed as an energy router for electricity in an analogous way to what network routers are for information. The SST impact on the system can be hence paramount, especially in terms of stability since it is essentially an active closed-loop regulated power converter. Within the SST itself however, with its different ac-dc, dc-dc and dc-ac stages, stability is also crucial, as it is well understood that for cascaded converter systems the interaction between stages is the cause of instability from a small-signal perspective. This paper represents an initial quest into the SST stability study, exploring two feed-forward control schemes for the ac-dc and dc-dc converter stages. Simulation and experimental results with a 7.2 kV ac 400 V dc, 20 kW laboratory prototype are presented for validation purposes.}, booktitle={2012 twenty-seventh annual ieee applied power electronics conference and exposition (apec)}, author={Wang, F. and Huang, A. and Wang, G. Y. and She, X. and Burgos, R.}, year={2012}, pages={1153–1158} }
 @inproceedings{wang_she_wang_huang_burgos_2012, title={Parallel operation of solid state transformer}, booktitle={2012 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={Wang, F. and She, X. and Wang, G. Y. and Huang, A. and Burgos, R.}, year={2012}, pages={1433–1438} }
 @inproceedings{huang_wang_lee_huang_2012, title={Reliability of 4H-SiC SBD/JBS diodes under repetitive surge current stress}, DOI={10.1109/ecce.2012.6342436}, abstractNote={The reliability of power diode under surge current stress is crucial to the applications like motor drives. In this paper, the single and repetitive surge reliability of the 4H-SiC Schottky Barrier Diodes (SBDs) and Junction Barrier Schottky (JBS) diodes have been tested and the corresponding failure mechanisms studied. The single surge test results of two SBDs and three JBS didoes suggest a 450W/mm2 constant power line of the safe operation area for single surge current with a half sinusoidal pulse width of 8.3ms. The stress tests show no degradation of SBDs up to 10,000 cycles of surge current below 34.9A/mm2. The JBS diodes show VF degradation after surge stress at different current levels, which might be dependent on the hole injection levels. The aluminum metallization and bipolar degradation are the main limits for the reliability of SiC diodes under surge conditions.}, booktitle={2012 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={Huang, X. and Wang, G. Y. and Lee, M. C. and Huang, A. Q.}, year={2012}, pages={2245–2248} }
 @inproceedings{she_burgos_wang_wang_huang_2012, title={Review of solid state transformer in the distribution system: From components to field application}, DOI={10.1109/ecce.2012.6342269}, abstractNote={The emergence of high power converters makes the modern power grid more active than it was before. One of the research directions in this area is the solid state transformer, which aims at replacing the traditional 50/60 Hz power transformer by means of high frequency isolated AC/AC solid state conversion techniques. This paper presents a systematical technology review essential for the development of solid state transformer in the distribution system, especially focusing on the following four areas: high voltage and high frequency power devices, high power and high frequency transformers, AC/AC converter topologies, and applications of solid state transformer in the distribution system. For each category, the state-of-art technologies are reviewed and possible research directions are presented. It is concluded that the solid state transformer is an emerging technology for the modernization of the future smart grid.}, booktitle={2012 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={She, X. and Burgos, R. and Wang, G. Y. and Wang, F. and Huang, A. Q.}, year={2012}, pages={4077–4084} }
 @inproceedings{huang_wang_jiang_huang_2012, title={Ruggedness analysis of 600V 4H-SiC JBS diodes under repetitive avalanche conditions}, DOI={10.1109/apec.2012.6166048}, abstractNote={The repetitive avalanche reliability of power rectifiers is crucial to the safe operation of the hard switching power converters under extreme conditions as well as transient voltage suppression (TVS) applications. In this paper, the ruggedness of two state-of-art 4H-SiC Junction Barrier Schottky (JBS) diodes under repetitive avalanche stresses has been studied. Two different post-stress behaviors have been observed: VF degradation and BV drifting for the two different JBS diodes. The VF degradation could happen to the device that avalanches in the active area. However, for the device that avalanches in the edge termination, the repetitive avalanche stress greatly increases the breakdown voltage for about 100V. These results bring new concerns for SiC devices that are expected to be operated in avalanche conditions.}, booktitle={2012 twenty-seventh annual ieee applied power electronics conference and exposition (apec)}, author={Huang, X. and Wang, G. Y. and Jiang, L. and Huang, A. Q.}, year={2012}, pages={1688–1691} }
 @inproceedings{wang_huang_li_2012, title={ZVS range extension of 10A 15kV SiC MOSFET based 20kW dual active half bridge (DHB) DC-DC converter}, DOI={10.1109/ecce.2012.6342631}, abstractNote={SiC MOSFET is favorable for high voltage applications due to its fast switching speed, low loss and high voltage rating compared with silicon power devices. This paper presents the switching performance of 10A 15kV SiC MOSFET and analyzes its switching loss when considering the impact of parasitic capacitance. A 20 kHz 20 kW Dual Active Half Bridge (DHB) dc-dc converter based on this new device is designed with full ZVS range. Simulation and experiment results are given to validate the analysis.}, booktitle={2012 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={Wang, G. Y. and Huang, A. and Li, C. S.}, year={2012}, pages={1533–1539} }
 @inproceedings{she_huang_wang_zhao_wang_yao_2011, title={A new voltage-balancing controller in cascaded multilevel converters}, DOI={10.1109/ecce.2011.6063766}, abstractNote={Voltage-balancing controller in cascaded multilevel converters has been discussed extensively in previous literatures where several effective methods have been proposed. The coupling effect between a voltage-balancing controller and the original system controller is however not addressed comprehensively. This paper proposes a new voltage-balancing controller for single-phase cascaded multilevel converters in a d-q coordinate. The theoretical finding shows that the proposed method can effectively eliminate the coupling between two controllers in both steady and dynamic state. Simulation and experimental results validate the proposed method.}, booktitle={2011 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={She, X. and Huang, A. Q. and Wang, G. Y. and Zhao, T. F. and Wang, F. and Yao, W. X.}, year={2011}, pages={177–184} }
 @inproceedings{wang_she_wang_kadavelugu_zhao_huang_yao_2011, title={Comparisons of different control strategies for 20kVA solid state transformer}, DOI={10.1109/ecce.2011.6064196}, abstractNote={This paper presents and compares different control strategies for 20kVA silicon IGBT based solid state transformer (SST). The SST has a cascaded seven level rectifier stage, three output parallel Dual Active Bridge (DAB) DC/DC stage and an inverter stage. The voltage of the three high voltage capacitors must be balanced for the safe operation of the IGBTs, however, the mismatch of power devices parameters and variance of high frequency transformer leakage inductance of the DAB stage will cause voltage unbalance for these capacitors as well as the power unbalance of the three output parallel DAB stages. This paper analyzed these effects and discussed the limitations and merits for several different control strategies. The newly proposed control strategy for the SST has been determined as the most suitable strategy in terms of performance and simplicity. Simulation and experiment results are presented to validate the analysis.}, booktitle={2011 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={Wang, G. Y. and She, X. and Wang, F. and Kadavelugu, A. and Zhao, T. F. and Huang, A. and Yao, W. X.}, year={2011}, pages={3173–3178} }
 @inproceedings{wang_baek_elliott_kadavelugu_wang_she_dutta_liu_zhao_yao_et al._2011, title={Design and hardware implementation of Gen-1 silicon based solid state transformer}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79955785263&partnerID=MN8TOARS}, DOI={10.1109/apec.2011.5744766}, abstractNote={This paper presents the design and hardware implementation and testing of 20kVA Gen-1 silicon based solid state transformer (SST), the high input voltage and high voltage isolation requirement are two major concerns for the SST design. So a 6.5kV 25A dual IGBT module has been customized packaged specially for this high voltage low current application, and an optically coupled high voltage sensor and IGBT gate driver has been designed in order to fulfill the high voltage isolation requirement. This paper also discusses the auxiliary power supply structure and thermal management for the SST power stage.}, booktitle={Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC}, author={Wang, G. and Baek, S. and Elliott, J. and Kadavelugu, A. and Wang, F. and She, X. and Dutta, S. and Liu, Y. and Zhao, T. and Yao, W. and et al.}, year={2011}, pages={1344–1349} }
 @article{bhattacharya_zhao_wang_dutta_baek_du_parkhideh_zhou_huang_2010, title={Design and Development of Generation-I Silicon based Solid State Transformer}, ISSN={["1048-2334"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77952195486&partnerID=MN8TOARS}, DOI={10.1109/apec.2010.5433455}, abstractNote={The Solid State Transformer (SST) is one of the key elements proposed in the National Science Foundation (NSF) Generation-III Engineering Research Center (ERC) “Future Renewable Electric Energy Delivery and Management” (FREEDM) Systems Center. The SST is used to enable active management of distributed renewable energy resources, energy storage devices and loads. In this paper, the Generation-I SST single-phase 20kVA, based on 6.5kV Si-IGBT is proposed for interface with 12kV distribution system voltage. The SST system design parameters, overall system efficiency, high frequency transformer design, dual active bridge converter, auxiliary power supply and gate drives are investigated. Design considerations and experimental results of the prototype SST are reported.}, journal={2010 TWENTY-FIFTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC)}, author={Bhattacharya, Subhashish and Zhao, Tiefu and Wang, Gangyao and Dutta, Sumit and Baek, Seunghun and Du, Yu and Parkhideh, Babak and Zhou, Xiaohu and Huang, Alex Q.}, year={2010}, pages={1666–1673} }
 @inproceedings{baek_du_wang_bhattacharya_2010, title={Design considerations of high voltage and high frequency transformer for solid state transformer application}, booktitle={Iecon 2010: 36th annual conference of the ieee industrial electronics society}, author={Baek, S. and Du, Y. and Wang, G. Y. and Bhattacharya, S.}, year={2010} }
 @article{zhao_wang_zeng_dutta_bhattacharya_huang_2010, title={Voltage and Power Balance Control for a Cascaded Multilevel Solid State Transformer}, ISSN={["1048-2334"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-77952178838&partnerID=MN8TOARS}, DOI={10.1109/apec.2010.5433584}, abstractNote={In this paper, a 20kVA Solid State Transformer (SST) based on 6.5kV IGBT is proposed for interface with 7.2kV distribution system voltage. The proposed SST consists of a cascaded multilevel AC/DC rectifier stage, a Dual Active Bridge (DAB) converter stage with high frequency transformers and a DC/AC inverter stage. Based on the single phase d-q vector control, a novel control strategy is proposed to balance the rectifier capacitor voltages and the real power through the DAB parallel modules. Furthermore, the power constraints of the voltage balance control are analyzed. The SST switching model simulation demonstrates the effectiveness of the proposed voltage and power balance controller. A 3kW SST scale-down prototype is implemented. The experiment results verify the single phase d-q vector controller for the SST cascaded multilevel rectifier.}, journal={2010 TWENTY-FIFTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC)}, author={Zhao, Tiefu and Wang, Gangyao and Zeng, Jie and Dutta, Sumit and Bhattacharya, Subhashish and Huang, Alex Q.}, year={2010}, pages={761–767} }
 @inproceedings{zhou_wang_lukic_bhattacharya_huang_2009, title={Multi-function bi-directional battery charger for plug-in hybrid electric vehicle application}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-72449142726&partnerID=MN8TOARS}, DOI={10.1109/ecce.2009.5316226}, abstractNote={A new multi-function bi-directional battery charger for plug-in hybrid electric vehicles (PHEV) is proposed based on the power circuitry configuration of an American house. This bi-directional charger can achieve three functions including battery charging, vehicle to grid (V2G) and vehicle to home (V2H), all of which are the major research areas of PHEV's integration with the power grid. The integration infrastructure and practical design issues are analyzed. The multiple control loop designs are presented for the three operation modes. Simulation and experimental results verify the functions and performance of the proposed charger. With the capability of achieving multiple functions, the bi-directional charger will contribute and enhance grid related research of PHEVs.}, booktitle={2009 IEEE Energy Conversion Congress and Exposition, ECCE 2009}, author={Zhou, X. and Wang, G. and Lukic, Srdjan and Bhattacharya, Subhashish and Huang, A.}, year={2009}, pages={3930–3936} }