A Fast and Robust Diagnostic Method for Multiple Open-Circuit Faults of Voltage-Source Inverters Through Line Voltage Magnitudes Analysis

In this article, a fast and robust diagnostic method for multiple open-circuit (OC) faults is presented for voltage-source inverters. Only two line voltages are used as diagnosis variables, which is economic, simple, and can reduce the influence caused by the failure rate of information sources. Possible magnitudes of these line voltage vectors are characterized in detail both for the healthy and faulty operations. Then, several voltage features are extracted for diagnosis. Single-switch open-circuit faults and double-switch open-circuit faults can be accurately and quickly located through the proposed method. The fastest diagnostic process can be finished in 1/20 of the fundamental period. The diagnostic results of the proposed method are not affected by certain load OC faults, which may lead to false diagnosis of the existing methods. Moreover, the proposed method is robust to different control strategies, filter components, and carrier frequencies. Experiments are carried out on a dSPACE platform, and the effectiveness of the proposed method is verified.