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

Abstract

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.

Multi-Amplification-Channel Active EMI Filter Based on Period Spread-Spectrum PWM for Common-Mode EMI Suppression

“…When the voltage-sensing current-compensating (VSCC) active EMI filter (AEF) is adopted, the CM voltage of the motor drive system can be sensed using the AEF, and the compensation current can be generated using the AEF to cancel the CM current so that the CM-conducted EMI can be suppressed. As the VSCC AEF does not use an inductive transformer to sense or compensate the EMI element (voltage/current), the volume and weight of the motor drive system is not significantly increased [6,7]. However, due to the limitation of the operation bandwidth of the operational amplifier (OPAMP) in the VSCC AEF, the compensation current generated using the AEF in some frequency ranges is distorted, and then the EMI suppression effect in the whole EMI frequency range is decreased [8].…”