Quantitative Fault Severity Estimation for High-Resistance Connection in PMSM Drive System

In this paper, a fault severity estimation method is presented for high-resistance connection (HRC) in a permanent magnet synchronous machine drive system, being dependent upon the zero sequence voltage component (ZSVC) and stator currents. According to the relationship between the stator current, ZSVC and resistance deviations, a bivariate quadratic equation group is established with regard to the resistance deviations caused by HRC. The resistance deviations are obtained by solving the equation group. Based on the obtained resistance deviations, not only the fault is diagnosed and the faulty phase is identified, but also the HRC fault severity is estimated. Both the simulation and experiment are studied to validate the fault severity estimation method. The results verify the effectiveness and robustness of the proposed fault severity estimation method.