EMI filter design methodology taking into account the static converter impedance

The classic procedure design of EMI filters determines the insertion loss of the common mode and differential mode filters under standardized 50© at the input and output impedances. In order to choose the more adapted filter topology for a static converter, it´s necessary to consider the exact impedances connected to the input and output port in operating conditions. These impedances represent the LISN and the static converter which are measured with the current injection method. For simulation purpose, equivalent electrical circuit models are obtained and then applied in the filter design process.