Bidirectional Three-phase Current Source Converter based Buck-boost AC/DC System using Bidirectional Switches


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 VRMS, LL/ (400 − 800) V AC/DC system.

2023 IEEE Transportation Electrification Conference & Expo (ITEC)
Ramandeep Narwal
Ramandeep Narwal
Ph.D. Candidate

Ramandeep Narwal is a Ph.D. candidate in the research group of Prof. Subhashish Bhattacharya at the FREEDM Systems Center, NC State University.