Comparison between Si IGBT and SiC MOSFET Inverters for AC Motor Drive

Abstract

Modern drive systems of high speed motor demand fast semiconductor devices based on power MOSFETs. They are characterized by faster switching than conventional IGBTs and they have better performance. The comparison between SiC MOSFET (CCS050M12CM2 1200V,50 A) and Si IGBT (SKM75GD124D 1200V, 75A) modules driving the asynchronous motor (AM) is presented in this paper. According to the comparison of these two converters from their datasheets and results from other papers, SiC MOSFET converters have smaller switching loss, they operate under higher switching frequency, require smaller heatsink, etc. than IGBT. In our experiments both modules are tested under the power supply voltage up to 550V and load current up to 20 A connected to the induction motor. SiC MOSFET inverter has approximately two times higher slew rate for both rise and fall time than Si IGBT inverter because MOSFETs switch faster than IGBTs. The capacitive currents arising due to voltage charge remained almost the same for both types of inverters.