A Mixed Logical Dynamic Model-Based Open-Circuit Fault Diagnosis Method for Five-Phase PMSM Drives

To improve the reliability of the five-phase permanent magnet synchronous motor system, an open-circuit fault diagnosis method based on the residual current of the mixed logical dynamic model is proposed. According to the continuous current state variables and discrete switching signals of the motor system, a mixed logical dynamic model is established to estimate the real-time motor current. The polarity of the residual current between the model and the actual current is selected as the diagnostic feature. Then, the faulty switch is located by building the fault table. The experiment shows that this method can effectively diagnose single and two open-circuit faults in the system, and the diagnosis time is less than 60% of the current cycle.