Analysis of Common Mode Current of Isolated Converters Caused by Imbalance Factor Mismatch

Abstract

This paper presents a novel methodology for estimating the common mode (CM) current in isolated converters. We applied mode conversion theory as related to imbalance factor mismatch in transmission lines to an LLC resonant converter, and derived a theoretical equation representing the CM current by examining four operation modes of the converter. The CM current described by our proposed equation agreed closely with the results of a circuit simulation, indicating that mode conversion theory specific to transmission lines is also effective for the CM current estimation in switching converter circuits.