Analysis and Reduction of Common-Mode EMI in Electric Actuators for VF MEA

This paper presents a method to reduce common-mode (CM) electromagnetic interference (EMI) emission from electric actuators powered from PWM rectifier-inverter drives for use on more electric aircraft. An EMI model is presented first from which a simplified system CM model is developed to serve as the basis for the analysis and the development of effective CM EMI reduction methods. The proposed method is to insert a high-impedance element in series with the CM EMI voltage source, and create a low-impedance path in parallel with the high-impedance element to bypass the CM current. The method effectively reduces the amplitude of the CM voltage that drives the input and output CM current such that less filtering would be required. Experimental results from a laboratory motor drive system are presented to verify the effects of the proposed method.