Investigation of Multi-Physical Characteristics in Coupling-Five-Phase Motor under Driver-Open-Phase Fault Condition for Small Propulsion System

This paper investigates the multi-physical characteristics of five-phase permanent magnet synchronous motors used for small propulsion system under open-phase fault condition occurred in driver. Due to the asymmetric phase windings in open faulty modes together with fractional-slot concentrated winding, excessive magneto-motive force harmonic components are generated, which may result in increasing the significantly eddy current loss in permanent magnet and produce the unbalanced radial force. The high eddy current loss leads to a huge rise in operating temperature, which may cause the thermal demagnetization of PMs, and the unbalanced radial force will create great vibration in motor under faulty condition. Therefore, in order to guarantee the high performance of the motor, the thermal and mechanical characteristics must be analyzed together with the magnetic properties that vary depending on the operating conditions. The analytical results confirm that the motor can operate well under faulty conditions.