Mitigation conducted-EMI emission strategy based on distributed parameters of power inverter system in electric vehicle

Large dv/dt and di/dt due to power device fast switching within a DC-fed voltage-type PWM inverter of high power density and high-efficiency motor drive system for electric vehicle (EV) always introduce unwanted high frequency noise current through parasitics/distributed parameters of the motor drive system. The complete test setup for conducted-EMI emission from the AC motor drive system of EV are built to measure the conducted voltage of DC cables. The CM EMI current paths at resonance frequencies 500KHz and 30MHz are analyzed based on the distribution parameters. The CM current equivalent circuits for 500 kHz and 30MHz are presented. The dominated elements responsible for the appearing resonances at 500 kHz and 30MHz in measurement results are determined. A mitigation conducted-EMI emission strategy based on distributed parameters of power inverter system in EV is proposed. Simulation and measurement are used to validate the mitigation mothed.