High frequency modeling method of EMI filters

This paper deals with a high frequency modeling method of the common and differential mode inductors used in EMI filters. These filters are intended to reduce conducted emissions generated by power static converters towards power network. To model the EMI filters, it is necessary to identify the various parameters of the passive elements: inductors and capacitors. Because of their major impact on filter efficiency, these elements must be identified with accuracy. In this study, high frequency model of common mode coupled inductors is proposed. Simulation results of the proposed model are compared to the experimental data obtained using the specific experimental setup. These results made it possible to validate the proposed filter model and its robustness in a frequency range varying from 9 kHz to 30 MHz. The proposed high frequency inductor models will be very helpful for design optimization of EMI filters, since the high frequency behaviour of the filter mainly depends on magnetic materials used and on the geometrical characteristics of winding.