Sensorless Speed Control of Five-Phase PMSM Drives in Case of a Single-Phase Open-Circuit Fault

This paper introduces a new method to track saliency in a five-phase permanent magnet synchronous motor in case of a single-phase open-circuit fault. The proposed method depends on measuring the dynamic current response of the motor line currents due to the insulated-gate bipolar transistor switching actions. In case of a single-phase open-circuit fault, a fault-tolerant control strategy to control the remaining healthy currents results in minor system performance degradation. The new strategy that is proposed in this paper to track the saliency includes software modifications only to the saliency tracking algorithm used in healthy mode in order to make it applicable in the cases of a single-phase open-circuit fault. It uses the fundamental pulse width modulation waveform obtained using a symmetric multi-phase space vector pulse width modulation only. Simulation results are provided to verify the effectiveness of the proposed design over a wide speed range under different load conditions.