Modeling and Suppression of Common-Mode Current Resonance in an All-in-One Motor Drive Module of Electric Vehicle

In all-in-one motor drive module of electric vehicle, common-mode (CM) current resonance seriously affects the electromagnetic compatibility (EMC) performance of the motor drive module. To achieve low-cost and effective elimination of CM current resonance, it is necessary to construct an all-in-one motor drive module electromagnetic interference (EMI) model and find out the relevant influencing factors. Due to complex structures, it is difficult to extract the parasitic parameters of dc busbar and bus capacitor in the all-in-one module. This article proposes an extraction method for stray inductance of dc busbar based on current-oscillation frequency, and builds a high-frequency model of multiport bus capacitor based on partial element equivalent circuit and genetic algorithm method. Accordingly, an overall EMI coupling model of the all-in-one module is constructed. The accuracy of the EMI model is verified by comparing simulation results with measurement results. Based on the EMI model, sensitivity analysis is performed to identify the primary CM resonant paths, and resonance mechanism of CM current of the system is analyzed. To eliminate CM current resonance, an EMC quantitative design method is developed. Experiments are performed to validate the effectiveness of the EMC quantitative design method. The problem of CM current resonance in the all-in-one motor drive module is solved effectively.