A novel fault diagnosis method in SVPWM voltage-source inverters for vector controlled induction motor drives

Abstract

This paper presents a novel single and multiple open circuit fault detection and identification method for three phase Voltage Source Inverter (VSI) fed vector controlled drives. In healthy condition, d-axis reference voltage is constant. When fault occurs, it is distorted, which is applied to dete ct the insulated-gate bipolar transistors (IGBTs) open circuit fault occurrence. The d-axis reference voltage distorted last for an interval time, the fault can be isolated by calculating the instant current vector rotating angles when the d-axis reference voltage gets distorted and recovered to constant, respectively, combined with space position of the current arc trajectory. The proposed method is fair robust to load torque changes and variable speed, and can be embedded into the existing drive software as a subroutine without excessive computational effort. The feasibility of the proposed fault diagnosis algorithm is evaluated by both simulation and experimental results.