Reduction of Harmonics and Inverter Temperature in Experimental GaN-based Motor Drive System at High Frequencies Using LC Filter

This paper presents an experimental analysis and evaluation in the reduction of harmonics, inverter temperature and loss in an interior permanent magnet motor (IPMSM) drive system with gallium nitride-field effect transistor (GaN-FET) devices at high carrier frequencies by using a low-pass LC filter. The pulse-width modulation (PWM) carrier frequency used in the experimental motor drive system is from 30 to 400 kHz. The LC filter is suitably designed according to the admittance of both IPMSM core and the filter for effectively mitigating the carrier harmonics and ringing in the measured motor voltage, current and magnetic flux density as well as the output current of the GaN inverter. Moreover, with the use of the designed LC filter, the measured temperature of the GaN inverter is significantly decreased. These can help to lower the loss and electromagnetic interference (EMI) issues in the considered IPMSM drive system. The main application of this study is for electric vehicles.