ITSC Fault Diagnosis Method for Dual Three-Phase Permanent Magnet Motor Based on Zero-Sequence Voltage Difference

This paper proposes an inter-turn short circuit (ITSC) fault diagnosis method for dual three-phase permanent magnet motor (DTPPMM) based on zero sequence voltage difference, where the zero-sequence voltage difference between two sets of three-phase windings is defined and is used for ITSC fault diagnosis, which reduces the calculation amount of fault diagnosis, compared with the use of zero-sequence voltage of each set of three-phase windings. The mathematical model of the DTPPMM with the ITSC fault is first established. Based on the mathematical model, zero sequence voltage difference is defined and is analyzed under healthy and ITSC faut conditions. Finally, according to zero sequence voltage difference, the fault indices are constructed for ITSC fault detection and localization. The effectiveness of the proposed ITSC fault diagnosis method is verified through simulation and experiment. Both the results show that the ITSC fault can be detected and the faulty phase can be located, showing the effectiveness of the proposed fault diagnosis method. Additionally, it is noted that two three-phase balanced resistor networks connected between the inverter and the DTPPMM are required to obtain the zero-sequence voltage difference.