Current Similarity Analysis-Based Open-Circuit Fault Diagnosis for Two-Level Three-Phase PWM Rectifier

This paper proposed a novel single and multiple transistors open-circuit fault diagnosis method for two-level three-phase pulse-width modulating rectifier based on topology symmetry analysis in healthy and faulty conditions. First, similarity measurements between any two phase current linklists contained samples in a period after reconstruction and shape analysis, such as Euclidean distance, correlation coefficient, and cosine angle, are used to describe the symmetry of topology and divide the faults into three classes, then two extra features are extracted to locate the fault to broken leg and transistors, respectively. The proposed diagnostic method is robust, low cost, and easy to insert to the existed control system. The effectiveness and merit were evaluated by experimental results.