Open circuit fault detection in PWM voltage source inverter for PMSM drive system

Abstract

In this paper, a simple and low-cost open-circuit fault detection and identification method for a pulse-width modulated (PWM) voltage-source inverter (VSI) employing a permanent magnet synchronous motor is proposed. An open-circuit fault of a power switch in the PWM VSI changes the corresponding terminal voltage and introduces the voltage distortions to each phase voltage. The proposed open-circuit fault diagnosis method employs the model reference adaptive system techniques and requires no additional sensors or electrical devices to detect the fault condition and identify the faulty switch. The proposed method has the features of fast diagnosis time, simple structure, and being easily inserted to the existing control algorithms as a subroutine without major medications. The simulations and experiments are carried out and the results show the effectiveness of the proposed method Index Terms: Fault detection, fault diagnosis, fault identification, model reference adaptive system (MRAS), open-circuit fault, pulse-width modulated voltage-source inverter (PWM VSI)