Hybrid Common-mode EMI Filter Design for Electric Vehicle Traction Inverters

A feedforward current-sense current-compensation (CSCC) active EMI filter (AEF) for the direct current-side common-mode (CM) electromagnetic interference (EMI) suppression of high-power electric vehicle traction inverters is analyzed and designed. A detailed design of the components with formulas is provided based on an analysis of the CSCC AEF, including the CSCC AEF topology and its implementation. The feedforward active filter stage was implemented using a simple current transformer and a small circuit board. Only a small passive filter with a high resonant frequency is required for high-frequency noise attenuation. The filter's effectiveness was validated using the simulation results and experimental measurements.