@inproceedings{narwal_rawat_kanale_cheng_agarwal_bhattacharya_baliga_hopkins_2023, title={Analysis and Characterization of Four-quadrant Switches based Commutation Cell}, volume={2023-March}, ISSN={["1048-2334"]}, url={http://dx.doi.org/10.1109/apec43580.2023.10131312}, DOI={10.1109/APEC43580.2023.10131312}, abstractNote={A four-quadrant switch (FQS) blocks either polarity voltage and controls current flow in both directions. Unlike voltage-source converters, in which two-quadrant switches operate over a narrow voltage range, four-quadrant switches are required to operate over a wide range of both voltage and current in applications such as matrix converters and current-source converters. Furthermore, matrix converters require multi-step commutation schemes compared to two-step schemes for current-bidirectional switch based voltage-source converters and voltage-bidirectional switch based current-source converters. This paper provides a generalized overview of commutation schemes used for two and four quadrant switches based two-level commutation cells, identifies comparison indices for FQS commutation schemes, and discusses the need for adaptive commutation-step times for wide voltage and current variation applications. Also, the static and dynamic characteristics of 1.2 kV rated FQS implementations utilizing commercial SiC MOSFETs from four different manufacturers and novel monolithic SiC BiDirectional Field Effect Transistor (BiDFET) have been reported.}, booktitle={2023 IEEE Applied Power Electronics Conference and Exposition (APEC)}, publisher={IEEE}, author={Narwal, Ramandeep and Rawat, Shubham and Kanale, Ajit and Cheng, Tzu-Hsuan and Agarwal, Aditi and Bhattacharya, Subhashish and Baliga, B. Jayant and Hopkins, Douglas C.}, year={2023}, month={Mar}, pages={209–216} }
 @article{narwal_bhattacharya_baliga_hopkins_2023, title={Bidirectional Three-phase Current Source Converter based Buck-boost AC/DC System using Bidirectional Switches}, ISSN={["2473-7631"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85168253560&partnerID=MN8TOARS}, DOI={10.1109/ITEC55900.2023.10186945}, abstractNote={The 1.2 kV 4H-SiC BiDirectional Field Effect Transistor (BiDFET) is the first monolithic SiC bidirectional switch, which offers a lower voltage drop and semiconductor devices count alternative to the reverse-voltage-blocking (RB) switch used in the current-source converters (CSC). The bidirectional switch based CSC also allows DC-link current reversal for bidirectional power flow and provides multiple system-level benefits in a buck-boost AC/DC system consisting of buck-type DC/DC converter and CSC. This paper discusses the selection of buck converter duty cycle and CSC modulation index for the system's buck-boost operation with a wide variation in DC voltage. CSC modulation schemes categorized based on the number of hard-turn-on transitions per switching cycle are also analyzed along with the three-step and four-step commutation schemes that are essential for the CSC commutation cells. Finally, the different schemes are evaluated and compared through the experimental results of a 10 kW, 480 $\mathbf{V}_{\mathbf{RMS},\mathbf{LL}}/$ (400 - 800) V AC/DC system.}, journal={2023 IEEE TRANSPORTATION ELECTRIFICATION CONFERENCE & EXPO, ITEC}, author={Narwal, Ramandeep and Bhattacharya, Subhashish and Baliga, B. Jayant and Hopkins, Douglas C.}, year={2023} }
 @inproceedings{wong_narwal_bhattacharya_baliga_hopkins_2023, title={Design and Optimization of High-frequency Transformer for Isolated Single-Stage Three-Phase AC/DC Converter using Bidirectional Switches}, DOI={10.1109/ecce53617.2023.10362506}, abstractNote={This paper presents the design and optimization of the high-frequency transformer for an isolated single-stage three-phase AC/DC converter enabled by the 4H-SiC BiDirectional Field Effect Transistor (BiDFET). Non-dominated Sorting Genetic Algorithm II (NSGA-II) is used to perform a multiobjective optimization to minimize loss, weight, and volume. A 20 kW, 50 kHz hardware prototype based on the selected optimal point is characterized by a power amplifier. The finite element analysis simulation results are also presented to validate the core magnetic flux density and winding electric field strength. The experimental prototype was tested at 800 Vdc/480 Vrms at 10 kW rated power.}, booktitle={2023 IEEE Energy Conversion Congress and Exposition (ECCE)}, publisher={IEEE}, author={Wong, Isaac and Narwal, Ramandeep and Bhattacharya, Subhashish and Baliga, B. Jayant and Hopkins, Douglas C.}, year={2023}, month={Oct} }
 @inproceedings{narwal_wong_bhattacharya_baliga_hopkins_2023, title={Isolated Single-stage Three-phase AC/DC Converter using Bidirectional Switches}, DOI={10.1109/ecce53617.2023.10362178}, abstractNote={The advent of the SiC Bidirectional FET (BiDFET), a monolithic 1.2 kV bidirectional switch, has rendered the single-stage three-phase AC/DC converter topology a promising approach for implementing AC/DC converters. This topology, which integrates a full-bridge converter with a single-phase to three-phase matrix converter via a high-frequency transformer, is particularly suitable for applications requiring galvanic isolation, buck-boost functionality, and bidirectional power flow. The single-stage design eliminates the need for bulky and unreliable electrolytic capacitors, and utilizes a single magnetic component for power transfer. In the matrix converter, bidirectional switches, which were traditionally implemented using combinations of multiple semiconductor devices such as MOSFETs, IGBTs, and diodes, can now be realized using the single-chip solution, BiDFET. This advancement leads to a lower switch count, compact converter implementation, with lower inductance commutation cells, thereby enhancing the overall efficiency and compactness of the system. The paper presents a unified model of the converter, considering all control parameters, including the duty cycles and phase shift of transformer voltages. Detailed expressions for power transfer, transformer currents, and currents at AC and DC ports are provided. Additionally, the paper outlines the conditions necessary for soft-switching of all switches and the commutation schemes required for the practical implementation of the matrix converter modulation scheme. A hardware prototype of a 10 kW, 480 VRMS, LL/ 800 V AC/DC system has been developed, and experimental results are presented to demonstrate its performance.}, booktitle={2023 IEEE Energy Conversion Congress and Exposition (ECCE)}, publisher={IEEE}, author={Narwal, Ramandeep and Wong, Isaac and Bhattacharya, Subhashish and Baliga, B. Jayant and Hopkins, Douglas C.}, year={2023}, month={Oct} }
 @article{bhattacharya_narwal_shah_baliga_agarwal_kanale_han_hopkins_cheng_2023, title={Power Conversion Systems Enabled by SiC BiDFET Device}, volume={10}, ISSN={["2329-9215"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85150062639&partnerID=MN8TOARS}, DOI={10.1109/MPEL.2023.3237060}, abstractNote={The BiDirectional Field-Effect Transistor (BiDFET) can enable circuit topologies requiring four-quadrant switches, that were earlier designed using discrete combinations of MOSFETs, IGBTs, GaN HEMTs, and PiN diodes. The monolithic nature of the BiDFET allows lower device count, smaller switch volume, lower inductance, and simpler packaging, and hence more reliable and commercially viable implementation in power electronics converters. The matrix converter topologies, now feasible using BiDFETs, can eliminate the bulky and unreliable dc link capacitors or inductors required for conventional voltage-source or current-source converters in ac–ac and ac–dc applications. The 1.2 kV BiDFET has the potential to disrupt all the applications utilizing 1.2 kV switches, including electric vehicle (EV) drivetrain, bidirectional EV chargers, industrial motor drives, solid-state transformers, datacenter power supplies, elevator drives, dc microgrids, energy storage grid integration, solid-state breakers, etc.}, number={1}, journal={IEEE POWER ELECTRONICS MAGAZINE}, author={Bhattacharya, Subhashish and Narwal, Ramandeep and Shah, Suyash Sushilkumar and Baliga, B. Jayant and Agarwal, Aditi and Kanale, Ajit and Han, Kijeong and Hopkins, Douglas C. and Cheng, Tzu-Hsuan}, year={2023}, month={Mar}, pages={39–43} }
 @article{baliga_hopkins_bhattacharya_agarwal_cheng_narwal_kanale_shah_han_2023, title={The BiDFET Device and Its Impact on Converters}, volume={10}, ISSN={["2329-9215"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85150024571&partnerID=MN8TOARS}, DOI={10.1109/MPEL.2023.3237059}, abstractNote={The matrix converter topology for direct ac-to-ac conversion offers elimination of the bulky and unreliable d.c. link capacitors used in the popular voltage-source inverter (VSI) with a front-end rectifier. The resulting more compact and higher efficiency implementation is a desirable solution for a wide variety of applications, such as photovoltaic energy generation, motor drives, and energy storage systems.}, number={1}, journal={IEEE POWER ELECTRONICS MAGAZINE}, author={Baliga, B. Jayant and Hopkins, Douglas and Bhattacharya, Subhashish and Agarwal, Aditi and Cheng, Tzu-Hsuan and Narwal, Ramandeep and Kanale, Ajit and Shah, Suyash Sushilkumar and Han, Kijeong}, year={2023}, month={Mar}, pages={20–27} }
 @misc{kanale_cheng_narwal_agarwal_baliga_bhattacharya_hopkins_2022, title={Design Considerations for Developing 1.2 kV 4H-SiC BiDFET-enabled Power Conversion Systems}, ISSN={["2329-3721"]}, url={http://dx.doi.org/10.1109/ECCE50734.2022.9947715}, DOI={10.1109/ECCE50734.2022.9947715}, abstractNote={Bidirectional switches are essential for cycloconverter and matrix converter applications to facilitate single-stage AC-AC conversion without intermediate energy storage elements. The 1.2 kV 4H-SiC BiDFET was developed as the first monolithic bidirectional SiC power transistor. This paper describes the design considerations taken into account while creating the BiDFET device and developing custom packages for housing the switch in discrete form for low power applications and in module form for high-power applications. The realized switches are characterized for their on-state and switching performance. The versatility of the BiDFET device is demonstrated by operating a single BiDFET H-bridge in voltage-source-inverter and current-source-inverter topologies only by varying the gate bias on the individual BiDFETs and reversing the input-output connections.}, journal={2022 IEEE Energy Conversion Congress and Exposition (ECCE)}, publisher={IEEE}, author={Kanale, Ajit and Cheng, Tzu-Hsuan and Narwal, Ramandeep and Agarwal, Aditi and Baliga, B. Jayant and Bhattacharya, Subhashish and Hopkins, Douglas C.}, year={2022}, month={Oct} }
 @article{shah_narwal_bhattacharya_kanale_cheng_mehrotra_agarwal_baliga_hopkins_2021, title={Optimized AC/DC Dual Active Bridge Converter using Monolithic SiC Bidirectional FET (BiDFET) for Solar PV Applications}, ISSN={["2329-3721"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85123361428&partnerID=MN8TOARS}, DOI={10.1109/ECCE47101.2021.9595533}, abstractNote={Grid interface power conversion systems for commercial, industrial and residential solar power generation are becoming ubiquitous due to the competitive cost of solar energy. The AC/DC dual active bridge (DAB) converter is an upcoming topology in industrial PV energy and energy storage applications, providing bidirectional power transfer and galvanic isolation. In this paper, the properties of a DAB-type converter are leveraged to propose a design optimization process. It can optimize the high-frequency RMS current, size of magnetic elements and zero-voltage-switching (ZVS) region of the converter. The resulting design is compared against that derived from a conventional approach. In addition, an algorithm to compute the harmonic currents at the DC and line frequency AC ports of the system is proposed, and the respective filter designs are presented. The optimized design of the AC/DC DAB converter is implemented using the newly developed, 1200 V, $46 \mathrm{m}\Omega$, four quadrant, SiC-based monolithic bidirectional FETs (BiDFET). Experimental results from the 2.3 kW, $400\mathrm{V}/277\mathrm{V}_{{\mathrm {RMS}}}$ hardware prototype are finally presented to verify the design process.}, journal={2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Shah, Suyash Sushilkumar and Narwal, Ramandeep and Bhattacharya, Subhashish and Kanale, Ajit and Cheng, Tzu-Hsuan and Mehrotra, Utkarsh and Agarwal, Aditi and Baliga, B. Jayant and Hopkins, Douglas C.}, year={2021}, pages={568–575} }