Influence of the common mode impedance paths on the design of the EMI filters used with SiC-buck converter

Abstract

This paper deals the design method of EMI filter associated with buck converter using silicon carbide (SiC) power semi-conductors. It's well known that to comply with EMC standards, EMI filters are necessary. The aim is to propose a design method based on an equivalent electrical circuit. Thus, the first step is the identification of the different elements of the proposed model but also the limits values of the parasitic elements of the passive components which play a major influence on the efficiency of the filters. The main objective is to study the influence of the common mode paths on the design of the filter before and after its installation. A filtering solution is proposed to reduce the high frequency disturbances caused by the fast SiC components. The simulation results obtained with the proposed model are compared with the measurements show the effectiveness of the proposed EMI filter design method.

A Hybrid Common Mode Choke Optimization Method for Input Line EMI Filter Design

“…Considering a specific core size and taking into account (12), an increased number of turns is one way to exploit a larger leakage inductance, but this will require a small wire size that limits RMS currents. Such a manner will also cause high winding losses, temperature rise and will expose the magnetic core to saturation as mentioned before .…”