Short-circuit fault diagnosis of SRM power converter based on interval current

The power converter is one of the core components of the Switched Reluctance Motor (SRM) speed control system, and it is also the weakest link of system reliability. Aimed at the problems of traditional power converter short-circuit fault diagnosis methods, such as additional hardware, large controller burden, limited diagnosis range, etc., taking the asymmetric half-bridge power converter as the research object, based on the theoretical analysis of the failure modes, the current sensors are rearranged to extract obvious fault feature, and a fault diagnosis method for power converters based on current analysis within a specific rotor position interval is proposed. In the single excitation interval of the current phase, the ratio of the difference between the output values of the other two phases current sensors and the output value of the previous phase can be used to quickly locate the faulty device. This method is not limited by the number of motor phases and control methods, the controller burden is small, and no additional hardware is required. Simulations and experiments verify the effectiveness of this method. © 2021, Editorial Board of JBUAA. All right reserved.