@article{wang_yu_mann_meyer_tarmoom_chenetz_zhang_speer_2023, title={Isolated 3-Level DCDC Converter With Complete ZVS Using Magnetizing Inductors}, volume={38}, ISSN={["1941-0107"]}, DOI={10.1109/TPEL.2022.3212202}, abstractNote={An isolated dc–dc converter with dedicated 3-level modulation is proposed to achieve a 4:1 output voltage range, and complete zero-voltage-switching (ZVS) of all active switches using the magnetizing inductors. The single input 3-level modulation scheme coordinates the phase-shift, duty cycle, and switching frequency to ensure 1) the magnetizing currents are independent of load voltage and current; 2) the output voltage is proportional to the modulation input. As a result, the dual half- and full-bridge modes of the switching network are unified and modeled as a voltage-controlled voltage source, with the same control parameters for both modes of operation. In addition, the magnetizing-to-series inductance ratios of the leading and lagging transformers are increased to 100 and 25 times, respectively. Therefore, the circulating current is low, and the series inductors can be integrated into the transformers. The proposed topology is intended for high-power applications with a wide output voltage range but less input voltage variation. A <inline-formula><tex-math notation="LaTeX">$\text{30}\,\text{kW}$</tex-math></inline-formula> prototype with a power density of <inline-formula><tex-math notation="LaTeX">$\text{7.2}\,\text{kW}/\text{L}$</tex-math></inline-formula> and an output voltage of <inline-formula><tex-math notation="LaTeX">$\text{165}\,\text{V}$</tex-math></inline-formula>-<inline-formula><tex-math notation="LaTeX">$\text{680}\,\text{V}$</tex-math></inline-formula> was built and tested to verify the characteristics and feasibility of the proposed H8 topology plus modulation scheme.}, number={2}, journal={IEEE TRANSACTIONS ON POWER ELECTRONICS}, author={Wang, Dakai and Yu, Wensong and Mann, Greg and Meyer, Dennis and Tarmoom, Ehab and Chenetz, Steven and Zhang, Xuning and Speer, Kevin}, year={2023}, month={Feb}, pages={1910–1923} }
 @article{awal_montes_teng_wang_bipu_yu_lukic_husain_2023, title={Medium Voltage Solid State Transformer for Extreme Fast Charging Applications}, ISSN={["1048-2334"]}, DOI={10.1109/APEC43580.2023.10131285}, abstractNote={A modular and scalable solid state transformer (SST) with direct medium voltage (MV) AC connectivity is proposed to enable DC extreme fast charging (XFC) of electric vehicles. Single-phase-modules (SPMs), each consisting of an active-front-end (AFE) stage and an isolated DC-DC stage, are connected in input-series-output-parallel (ISOP) configuration. The modular hardware is co-designed with decentralized control of the DC-DC stages where voltage and power balancing are achieved by each SPM using only its local sensor feedback; a centralized controller (CC) regulates the low voltage (LV) DC bus through the AFE stages without any sensor feedback form the SPMs. The controller architecture contrasts sharply with the prior art for MV AC to LV DC SSTs where high-speed bidirectional communication among SPMs and a CC are required for module-level voltage and power balancing, which severely limits the scalability and practical realization of higher voltage and higher power units. Detailed small-signal analysis and controller design guidelines are developed. Furthermore, a soft start-up strategy is presented. The proposed converter and control structure are validated through simulation and experimental results.}, journal={2023 IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, APEC}, author={Awal, M. A. and Montes, Oscar Andres and Teng, Fei and Wang, Dakai and Bipu, Md Rashed Hasan and Yu, Wensong and Lukic, Srdjan and Husain, Iqbal}, year={2023}, pages={1528–1535} }
 @article{chen_yu_wang_2022, title={Bidirectional H8 AC-DC Topology Combining Advantages of Both Diode-Clamped and Flying-Capacitor Three-Level Converters}, volume={10}, ISSN={["2168-6785"]}, DOI={10.1109/JESTPE.2021.3088390}, abstractNote={A three-level bidirectional ac–dc converter with H8 topology is proposed to combine the advantages of both neutral-point clamped and flying-capacitor (FC) three-level converters for medium-voltage (MV) ac–dc solid-state transformer (SST) applications. The innovative H8 converter features self-balanced capacitor voltage, common-mode voltage elimination, and small capacitance of the FCs. The proposed carrier-based modulation enables the H8 converter to operate under both active and reactive power conditions. A 10-kVA ac–dc converter prototype with 1.7-kV SiC MOSFETs and 3.3-kV SiC diodes verifies the feasibility and advantages of the proposed topology and the modulation method. The capacitance of the FCs in the H8 converter is reduced by 45 times compared to that of the FC converters. The H8 converter efficiency is tested up to 99% at 2-kV dc voltage. The proposed H8 converter is suitable for the next-generation PV inverter, grid-forming inverter, MV fast charger, and SST applications.}, number={4}, journal={IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS}, author={Chen, Siyuan and Yu, Wensong and Wang, Dakai}, year={2022}, month={Aug}, pages={3643–3651} }
 @article{wang_yu_2022, title={Soft-Switching dv/dt Filter with Ultra High Power Density and 50% Power Loss Savings for 150 kW SiC Motor Drives}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE50734.2022.9947467}, abstractNote={This paper presents a SiC-based soft-switching dv/dt filter using a parallel inductor to achieve ultra-high efficiency and limit the output dv/dt below 6V/ns for high-power motor drive applications. All main SiC devices are switched with the fastest speed and minimized switching loss due to the zero-voltage-switching under any input/output voltage and load conditions. The filter inductor RMS current is reduced by 86% using an inductor in parallel instead of in series with the load. The proposed matrix solenoid air-core filter inductor with near field leakage flux cancellation increases the energy density by two times compared to the toroidal shape. Compared to the motor drives with passive dv/dt filters, the total power loss of the motor drive with the soft-switching dv/dt filter is reduced by 50%, and the dv/dt filter volume reduction is by 90%. Simulation and experimental results and comparisons demonstrate the feasibility and advantages of the soft-switching dv/dt filter.}, journal={2022 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Wang, Dakai and Yu, Wensong}, year={2022} }