A Modeling Technique for Designing High-Frequency Three-Phase Common-Mode Inductors

Switching speed of the next-generation power devices based on the wide-bandgap semiconductors such as silicon carbide and gallium nitride are more than ten times faster than the conventional silicon insulated-gate bipolar transistors. This may increase frequency ranges of electromagnetic noise accompanied by switching operations of power converters. Besides, the operating frequency ranges of noise filters are limited due to frequency dependencies of magnetic materials and parasitic components of passive components, thus, the realization of the high-frequency (HF) noise filter with the operating frequency range beyond several ten megahertz is difficult. This paper presents a modeling technique for estimating the operating frequency range of the HF three-phase common-mode (CM) inductors. The proposed method includes a novel simple estimation technique of winding stray capacitance. The CM impedance measurement results validate that the proposing model can estimate the operating frequency range of the HF three-phase CM inductor while securing practically sufficient precision at the design-stage.