@inproceedings{du_huang_wang_lukic_2012, title={A novel high step-up ratio bi-directional DC-DC converter}, DOI={10.1109/apec.2012.6165870}, abstractNote={High step-up ratio bi-directional DC-DC converter is attractive in energy storage systems for renewable energy generation and in electric vehicle applications. A novel high step-up ratio bi-directional DC-DC converter and its alternative topology which can achieve soft switching in full load range and wide voltage range are proposed. The operation principle of the converter is analyzed in this paper. The modulation strategy and the optimum operation region are presented. A 400kHz 14.4V to 360V prototype was built to verify the analysis and the operation of the proposed converter. Zero voltage switching of all the switches was verified by experimental waveforms. The tested converter efficiency at 450W is 94.1%.}, booktitle={2012 twenty-seventh annual ieee applied power electronics conference and exposition (apec)}, author={Du, Y. and Huang, A. Q. and Wang, M. Q. and Lukic, S. M.}, year={2012}, pages={524–531} }
 @article{du_lukic_jacobson_huang_2012, title={Modulation Technique to Reverse Power Flow for the Isolated Series Resonant DC-DC Converter With Clamped Capacitor Voltage}, volume={59}, ISSN={["1557-9948"]}, DOI={10.1109/tie.2011.2175669}, abstractNote={The series resonant dc-dc converter with clamped capacitor voltage exhibits excellent characteristics in forward operating mode, including simple control, high reliability, soft switching, high power density, and inherently limited load fault current. However, the conventional single angle phase-shift modulation that works well in the forward mode cannot reverse the power flow. In this paper, we propose a modulation strategy for reverse-mode operation by utilizing three phase-shift angles afforded by the two active full bridges of the circuit. We identify the optimal modulation trajectories in 3-D modulation space and implement a lookup-table-based modulator for power flow control. A high-fidelity simulation model of a 35-kW 750-V input, 300-600-V output, and 50-kHz insulated-gate bipolar-transistor-based converter was used for verification. The proposed modulation scheme and efficiency calculations were validated on a scaled-down (15-kW) prototype. The power loss distribution was analyzed for further converter efficiency optimization.}, number={12}, journal={IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS}, author={Du, Yu and Lukic, Srdjan M. and Jacobson, Boris S. and Huang, Alex Q.}, year={2012}, month={Dec}, pages={4617–4628} }
 @inproceedings{du_lukic_jacobson_huang_2011, title={Review of high power isolated Bi-directional DC-DC converters for PHEV/EV DC charging infrastructure}, DOI={10.1109/ecce.2011.6063818}, abstractNote={PHEV/EV DC charging infrastructure attracts more and more attention recently. High power isolated bi-directional DC-DC converters provide galvanic isolation, V2G capability and reduce the cost and footprint of the system. Maintaining high power efficiency in wide vehicle battery pack voltage range is required. Three full bridge based high power bi-directional DC-DC converters are conceptually designed for this application and their advantages and disadvantages are addressed. Experimental test bench is built and efficiency evaluation for bi-directional operation is reported.}, booktitle={2011 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={Du, Y. and Lukic, S. and Jacobson, B. and Huang, A.}, year={2011}, pages={553–560} }
 @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} }
 @inproceedings{du_baek_bhattacharya_huang_2010, title={High-voltage high-frequency transformer design for a 7.2kV to 120V/240V 20kVA solid state transformer}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78751558902&partnerID=MN8TOARS}, DOI={10.1109/iecon.2010.5674828}, abstractNote={Solid state transformer (SST) exhibits good features such as high power density, small volume and weight, controlled power factor, voltage sag ride through, etc. compared with traditional line frequency transformer. The 7.2kV AC to 120V/240V AC 20kVA solid state transformer is a key component of the future renewable electric energy delivery and management (FREEDM) systems as the interface between the 7.2kV distribution grid and the low voltage residential micro-grid. Three cascaded 6.7kVA high-voltage high-frequency transformers operating at 3kHz are employed to convert voltage from 3800V high voltage DC link of each cascaded stage to 400V low voltage DC link. The transformer is required to withstand at least 15kV high frequency voltage insulation continuously. Transformer magnetic core materials were reviewed and compared. Winding layout alternatives for leakage, magnetizing inductance and insulation were compared. An insulation strategy based on split core and separate winding structure with inserted insulation layer between the C cores was proposed. One 6.7kVA high voltage high frequency transformer prototype was built and the test results were reported.}, booktitle={IECON Proceedings (Industrial Electronics Conference)}, author={Du, Y. and Baek, S. and Bhattacharya, Subhashish and Huang, A.Q.}, year={2010}, pages={493–498} }
 @article{du_zhou_bai_lukic_huang_2010, title={Review of Non-isolated Bi-directional DC-DC Converters for Plug-in Hybrid Electric Vehicle Charge Station Application at Municipal Parking Decks}, ISSN={["1048-2334"]}, DOI={10.1109/apec.2010.5433359}, abstractNote={There is a growing interest on plug-in hybrid electric vehicles (PHEV's) due to energy security and green house gas emission issues, as well as the low electricity fuel cost. As battery capacity and all-electric range of PHEV's are improved, and potentially some PHEV's or EV's need fast charging, there is increased demand to build high power off-board charging infrastructures. A charge station architecture for municipal parking decks has been proposed, which has a DC microgrid to interface with multiple DC-DC chargers, distributed renewable power generations and energy storage, and provides functionalities of normal and rapid charging, grid support such as reactive and real power injection (including V2G), current harmonic filtering and load balance. Several non-isolated bidirectional DC-DC converters suited for charge station applications have been reviewed and compared, as the major focus of this paper. Half bridge converter is a good candidate but it is difficult to maintain high efficiency in wide battery pack voltage range. A variable frequency pulse width modulation (VFPWM) scheme is proposed to mitigate this issue. Finally three-level bi-directional DC-DC converter is suggested to be employed in this application. A 10kW prototype verifies that 95.1–97.9% full load efficiency can be achieved in charging mode with 180–360V battery pack voltage. In addition, the inductor size is only one third of the half bridge counterpart, which is a great advantage for high power converters.}, journal={2010 TWENTY-FIFTH ANNUAL IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC)}, author={Du, Yu and Zhou, Xiaohu and Bai, Sanzhong and Lukic, Srdjan and Huang, Alex}, year={2010}, pages={1145–1151} }
 @inproceedings{wang_du_bhattacharya_huang_2009, title={Characterization, modeling of 10-kV SiC JBS diodes and their application prospect in X-ray generators}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-72449197461&partnerID=MN8TOARS}, DOI={10.1109/ecce.2009.5315963}, abstractNote={The 10-kV Silicon Carbide (SiC) Junction Barrier Schottky (JBS) diodes are currently being developed by a number of organizations in the United States with the aim to enable their applications in high voltage power conversions. The aim of this paper is to characterize and model the 10-kV SiC JBS diode so that their prospect and benefits in power electronic systems can be provided. Using the SPICE model of the 10-kV 5A SiC JBS diode, the advantages of 10-kV SiC JBS diodes in the application of X-ray generators were shown by PSPICE simulations for the first time. The simulation results predict that the 10-kV SiC JBS diodes based high voltage rectifiers in X-ray generators can greatly reduce the number of series diodes required and power loss than compared to the 1-kV silicon ultra fast recovery diodes based rectifiers.}, booktitle={2009 IEEE Energy Conversion Congress and Exposition, ECCE 2009}, author={Wang, J. and Du, Y. and Bhattacharya, Subhashish and Huang, A.Q.}, year={2009}, pages={1488–1493} }