High-Frequency Equivalent Circuit of PM Synchronous Motor Driven by PWM Inverter

Abstract

This paper deals with the high-frequency equivalent circuits of permanent magnet synchronous motor (PMSM) driven by a PWM inverter. The leakage current (common-mode current) flows through stray capacitance among stator windings and iron core (frame) of an synchronous motor at the switching instants of inverter transistors. A high-frequency equivalent circuits of PMSM are derived based on the frequency characteristics of the high-frequency zero-phase-impedance and line-to-line-impedance of synchronous motor. The validity of the proposed equivalent circuit is confirmed by simulation considering parasitic capacitance of the inverter.