Modeling and Design of Common Mode and Differential Mode Filter for PWM Converters

摘要

This paper presents a method to model a back-to-back converter and the additional passive filter system. The mathematical modeling method followed the step of converting the three-phase system to single phase systems by separating the differential mode (DM) and common mode (CM) noise circuit for the design of the filter components separately. The model accounts for parasitic components in the converters and presents an indirect method of estimating parasitic capacitance for CM filter design. Design rules for the different components are summarized. Results from a lab prototype are presented and show good correspondence to the model.