Comparison of Power Loss in SiC-MOSFET and Si-IGBT Traction Inverter with Variable Switching Frequency for Electric Vehicle Application

In this paper, the effect of using WBG semiconductors in a PMSM motor drive system for electric vehicles (EVs) is studied. This study aims to investigate power losses of traction inverters at various switching frequencies and total harmonic distortion of phase current. Moreover, power losses of SiC-MOSFET and Si-IGBT-based inverters are compared. Increasing the switching frequency in inverters is one way to increase the motor efficiency, as the harmonic components in the current waveform reduce, which leads to a reduction in motor iron losses. However, utilization of Si-IGBT power switches in inverters at high frequencies leads to an increase in inverter losses. On the other hand, the usage of WBG devices in the inverters reduces power loss. It has been found in this paper that the conduction and switching losses were reduced by up to 60% as compared to Si-IGBT. The results confirm that increasing the switching frequency reduces the THD in the phase current and that WBG devices can enhance the efficiency of the motor drive system in electric vehicles.