Study of High Frequency Characteristics Modeling and EMI Suppression of Common Mode Chokes

This paper proposes a method for building a high-frequency model of common-mode chokes in the frequency range of 9kHz to 200MHz. The method only needs to measure the common mode and differential mode impedance data of the common mode choke, and then use the differential evolution algorithm to process the impedance data to complete its high-frequency modeling. Comparison with the high-frequency model obtained by using a genetic algorithm shows that the method has high accuracy. After the high frequency modeling of the common mode chokes, the high frequency modeling of the X and Y capacitors is performed using the differential evolution algorithm, and the high frequency model of the EMI filter is obtained by combining it with the established high frequency model of common mode chokes. By comparing the measured and simulated conducted interference noise suppression effect of the EMI filter, the high frequency model of the common mode chokes is verified to suppress the conducted interference, and the effectiveness of the common mode choke high frequency modeling method is determined.