Unified Open-Phase Fault Diagnosis of Five-Phase PMSM System in Normal Operation and Fault-Tolerant Operation Modes

Open phase fault (OPF) is a common electrical fault of five-phase permanent magnet synchronous motor (PMSM) system. The OPF not only can occur in normal operation mode, but also in fault-tolerant operation mode. Hence, this paper proposes a unified OPF diagnosis method for five-phase PMSM system in multiple operation modes (normal operation and fault-tolerant operation modes). The proposed method includes two steps: fault detection and fault location. In multiple operation modes, fault detection can be uniformly achieved by a single fault indicator, and fault location can be uniformly implemented by space current vector, reducing the fault diagnosis complexity. Both the simulation and experimental results show that the proposed method can achieve unified OPF diagnosis of five-phase PMSM system in multiple operating modes. In addition, the proposed method has the strong robustness to the speed and load disturbance.