Analysis and Prediction of EMI in Three-Phase Rectifier

EMI problems in power electronics equipment keeps on increasing when power electronics device widely used. As the important component of power electronics equipment, EMI caused by phase switching in three-phase rectifier not only affected normal operation of its connected equipment but also polluted public grid system. EMI in AC and DC of three-phase rectifier were analyzed in detail. The equivalent circuit models of EMI in AC and DC of three-phase rectifier were built and the mathematics description in S domain of EMI was deduced. And the prediction frequency spectrum of EMI in three-phase rectifier was programmed by MATLAB, which could provide theoretical basis for design of EMI filters.