IPMSM Electromagnetic Noise Impact Analysis Based on Rotor Radial Parameter Optimization

In this paper, the inner permanent magnet synchronous motor electromagnetic noise of a certain new energy vehicle with 8 poles 48 slots is studied. According to the harmonic principle of electromagnetic force in space and time, the noise peak is determined to be caused by the 0-order 12f electromagnetic force at 7800rpm by noise order slice. Therefore, aiming at weakening the 0-order 12f electromagnetic force, the sensitivity analysis of five parameters, including rotor radial side magnetic steel angle, outer magnetic bridge thickness, groove depth of auxiliary groove at q-axis and electric angle of inner and outer notches, was carried out in Ansys Motor-CAD finite element software, and the optimal parameter combination was determined. The acceleration noise and electromagnetic torque of motor before and after optimization were simulated and compared. The results show that rotor radial parameter optimization can weaken the electromagnetic force which contributes a lot to the electromagnetic noise, among which the slot depth and the angle of the inner notch have more obvious weakening effects on the electromagnetic force than the other three parameters, and the electromagnetic noise of the optimized motor can be effectively improved while ensuring the output performance.