Characterization and Design of Three-Phase EMI Noise Separators for Three-Phase Power Electronics Systems

In this paper, three-phase noise is first analyzed using symmetrical component theory. Three-phase noise separators are modeled and characterized using symmetrical component theory and
S
-parameters. The critical formulas used to evaluate a three-phase noise separator are derived. A function scheme and a circuit structure for three-phase noise separators are proposed based on the theory developed. The technique to design a high-performance three-phase noise separator is explored. A three-phase noise separator prototype is finally built, measured, and evaluated using the theory developed in this paper. The prototype is used in a practical three-phase power electronics system for electromagnetic interference measurement.