Simplified impedance modeling and analysis for inter-turn fault of IPM-type BLDC motor

Abstract

This paper proposes a finite element method (FEM)-based model of an interior permanent magnet (IPM)-type BLDC motor having stator inter-turn faults. We also propose impedance modeling of the magnetic characteristics. By integrating the developed model with a current-controlled voltage source inverter (CCVSI) model, the distributed characteristics of an inter-turn fault operated by a six-switch inverter are investigated considering speed control. Moreover, this paper presents the flux density distribution and torque characteristics for analyzing the inter-turn fault of an IPM-type BLDC motor. Additionally, fault impedance is required to calculate the circulating current that causes magnetic distortion. Thus, this paper proposes a method for estimating the circulating current taking into account the voltage at the shorted turn and the rotating speed. The analysis data were verified experimentally.