The Loss and Efficiency Analysis and Research of Interior Permanent Magnet Synchronous Motors for Traction Applications

An IPMSM with I2V type rotor topology structure is proposed, its loss, efficiency and torque are analyzed and compared with V and IV type. Firstly, the optimized rotor topology structures are used to analyze the no-load air-gap flux density waveform and harmonic contents of the IPMSM. The results show that the THD of the no-load air-gap flux density with the I2V type is the smallest and the sinusoidal degree of the waveform is the highest. Secondly, the loss of the IPMSM with optimized rotor topology structures are analyzed and compared. Compared with the other two rotors, the results show that the iron loss of the IPMSM with the I2V type is the smallest. The iron loss of the IPMSM with I2V type is significantly less than that of the other two rotors especially under the deep flux weakening conditions. The output torque of the IPMSM under different current angles, current densities and speed are analyzed and compared. The results show that the torque performance of the IPMSM with I2V type is better than the other two rotors. this paper proposes a simple and effective method to optimize the position and diameter of the magnetic isolation holes by establishing a parameterized model. The results show that the torque ripple and cogging torque with the further optimized I2V type rotor topology structure are greatly reduced, the iron loss and magnet loss are also effectively reduced. Finally, the von Mises stress and the total displacement of the rotor deformation of the IPMSM with the further optimized I2V type under different working conditions are verified by finite element analysis. The results show that the rotor will not rupture, the displacement is small enough to avoid the touch between stator and rotor.