Development and demonstration of silicon carbide (SiC) motor drive inverter modules

This paper describes a new SiC-based motor drive technology used to achieve compact power conversion. The static and dynamic characterization of 600 V SiC MOS-enhanced JFETs and SiC Schottky free-wheeling diodes (FWDs) designed and fabricated at Rockwell Scientific, are performed. Single 5 A SiC JFET and Schottky FWD die with a voltage rating of 600 V are paralleled to obtain 10 A, and 25 A, current ratings. The power loss and related voltage and current stress of the SiC MOS-enhanced JFET and SiC Schottky FWD are measured and compared to that of a state-of-the-art silicon IGBTs and PIN FWDs with ratings equal to the SiC ratings. For the same power rating (25 A, 600 V), the area of the SiC die making up the inverter module are about 60% of a commercial 25 A IGBT die. The Rockwell Automation RA Model 1336 motor controller is used, with its gate drive circuit modified to control the SiC depletion-mode MOS-enhanced JFETs, to control a motor. SiC inverter modules are fabricated and used to successfully drive 1 hp to 10 hp motors. To our knowledge, this is the first time that a motor drive using SiC inverter modules has been demonstrated.