An SiC inverter for high speed permanent magnet synchronous machines

This paper present experimental results obtained during the construction of an SiC based inverter for high speed permanent magnet synchronous machines (PMSM). First a comparison between an IGBT and SiC modules used for the same application is presented. The modules static and switching losses are experimentally obtained and compared. The SiC module show significantly lower switching losses. Then the SiC inverter design is described and experimental results are shown. It is found that parasitic inductances in both the gate driver and DC intermediate circuit play a major role and need to be minimized. One procedure using vertically aligned PCB traces is described and measured results are presented. The presented SiC based inverter was successfully tested with the high speed PMSM up to the application full voltage 600V. It was also tested with a high switching frequency up to 500kHz although the target frequency is only 100kHz.