Predicting Worst Case Common-Mode Behavior in Power Electronic Based Systems

This paper first introduces a technique for characterizing the common-mode (CM) behavior of a dc-fed power converter. This characterization technique relies only on measurements taken at the terminals of the power converter, without the need for detailed knowledge of the converter design, and describes the CM behavior in terms of a Thevenin equivalent circuit. Next, an analysis method establishes an upper-bound on the magnitude of the CM potential in a system with one or more power converters. Lastly, the Thevenin equivalent circuit model is generalized to a two-port equivalent circuit so that CM behavior can be modeled at both the input and the output of the power converter.