Torque Calculation of Five-Phase Interior Permanent Magnet Machine Using Improved Analytical Method

This paper proposes a new torque analytical method (AM) for five-phase interior permanent magnet synchronous machine (IPMSM) with shifted asymmetrical rotor pole. The key of this method is to consider the permanent magnet (PM) torque and the reluctance torque simultaneously, by using the Lorenz force law. The analytical expressions, including stator magnetomotive force (MMF), rotor MMF generated by PMs and rotor MMF generated by stator MMF, are first derived. Then, Lorentz force law is used to calculate PM torque and reluctance torque, respectively. In order to improve the precision of electromagnetic torque calculation, stator slotting effect under shifted asymmetrical rotor pole is taken into consideration. Finally, the AM is verified by finite element method and experiment. The results show that proposed AM is good enough to predict the torque performance of IPMSM with shifted asymmetrical rotor pole.