100kW 3-phase ARCP soft switched SiC (S2SiC) inverter - design and in-lab test verification

The auxiliary resonant commuted pole (ARCP) inverter is one of the most promising soft switching inverter topologies. In the ARCP inverter, resonant current supplied by the auxiliary circuit ensures soft switching operation. Successful soft switching of inverter results in lower level of electrical and thermal stresses on semiconductor power devices, and leads to lower temperature rise, and higher inverter efficiency. In this paper, 100kW ARCP 3-phase SiC inverter system was designed, fabricated, and double pulse test (DPT) test-verified to prove out feasibility for continuous operation. An excessive voltage overshoot was found under hard start, which poses a potential risk for premature failure of SiC power devices. To mitigate excessive voltage overshoot, authors have developed inverter start-up technique that was test-verified by DPT method. As expected with the developed soft-starting technique, power devices in the soft switched SiC (S2SiC) inverter don’t experience excessive voltage overshoot. The developed hardware for the S2SiC inverter and its control method is ready for interior permanent magnet (IPM) motor control. In this final paper, results from S2SiC inverter feeding a three-phase R-L load are included. Results to be obtained from a back-to-back motor dynamometer-based set-up will be reported in a future paper, where ARCP-based S2SiC inverter will drive an interior permanent magnet (IPM) motor with objective to prove out vitality and a compelling application of the 100kW S2SiC inverter.