A Hybrid PWM Modulation for EMI Filter Size Reduction in a 10 kW GaN-Based Three Phase Inverter

Abstract

In this paper, a hybrid PWM modulation method is proposed to reduce the EMI filter size of GaN based inverters. Time-based PWM modulation and frequency-based modulation methods are combined to achieve a reduced EMI profile, which reduces the filter size required to meet EMI standards. An EMI test bed based on the CISPR EMI standard is built using a 10-kW GaN inverter and modeled using LTspice simulation. The simulation model parameters were finely tuned to represent the actual system. Experimental EMI tests were conducted to verify the simulation model. The hybrid method is simulated and tested achieving an attenuation of 7-12 dBs. It is shown that this method reduces the EMI filter size by 21% which helps to increases the power density of the inverter.