Cost Function-Based Open-Phase Fault Diagnosis for PMSM Drive System With Model Predictive Current Control

Open-phase fault (OPF) in the permanent magnet synchronous machine (PMSM) drive system is one of the most prevalent failures due to the resulting large electromagnetic torque ripples and serious mechanical vibration. To improve the reliability of the PMSM drive system, several OPF diagnosis methods were studied and were mainly focused on vector control system. Recently, model predictive control (MPC) has been emerging as a popular control method for the PMSM drive system owing to its simple structure and excellent dynamic performance. However, so far, there are no special OPF diagnosis methods for the model predictive controlled PMSM drive system. Hence, this article first proposes a cost function-based OPF diagnosis method for the model predictive controlled PMSM drive system, considering the characteristics of MPC system. The dc component and second harmonic component in the cost function are used for the OPF diagnosis, and the initial phase angle differences are defined to locate the faulty phase. The experimental results show that, by the proposed fault diagnosis method, not only the OPF can be rapidly detected, but also the faulty phase can be effectively located. Moreover, the proposed method can be implemented simply and is robust against the operating point and parameter variations of the PMSM drive system. This article proposes an OPF diagnosis method for the model predictive controlled PMSM drive system based on cost function, taking into account the characteristics of the MPCC system. The experimental results verify the effectiveness of the proposed method. From the theoretical analysis and experimental results, the following works and conclusion are drawn.