A new behavioural model for performance evaluation of common mode chokes

A behavioural model for performance evaluation of a common mode choke (CMC) is proposed: the topology and methods used to model the different properties of the CMC are presented. It combines an accurate model of the complex permeability, of the saturation, of leakage inductances and of parasitic capacitances. Inputs needed from the designer are measured values of currents, voltages and impedance of the actual system, and parameters available in literature and/or from manufacturers for the modelled CMC. The behavioural model is essential in simulation of EMI effects.