Optimized Design of Three‐Phase EMI Filter for Electric Vehicle Onboard Charging System

ABSTRACT The onboard charging system of electric vehicles operates with high voltage, high current, and high‐frequency switching components, which generates electromagnetic interference that not only affects the operating characteristics of other electronic devices in the vehicle but also directly affects the driving safety of the vehicle in serious cases. To address the electromagnetic compatibility of the electric vehicle onboard charging system, considering the influence of high‐frequency oscillations of wide‐bandwidth semiconductor devices, analyzing the rules for layout and wiring of three‐phase EMI filter utilizing the finite element method, proposed parasitic inductance mutual cancellation technique, two circuit design methods applying parasitic inductance mutual cancellation techniques have been investigated, enabling optimization of three‐phase EMI filter. Application of a three‐phase EMI filter applying parasitic inductance mutual cancellation technique to an onboard charging system and comparing the performance with that of traditional EMI filter, the experimental results show that the proposed three‐phase EMI filter is more effective in filtering out high‐frequency noise.