Effect of vibration and noise on IPMSM type integrated starter and generator according to number of slots

Integrated starter and generator (ISG) is one of the important component for hybrid electric vehicle (HEV). The main function of ISG is starting of engine after idle stop and generating during vehicle driving. When ISG starts engine, acoustic noise can be detected inside a vehicle. Many of such electric noise of the motor are produced by electro-magnetic exciting force and it is amplified to meet resonance frequency of system. Based on these faces, two kinds of method to reduce noise and vibration of system can be considered. The one is reduction of electro-magnetic exciting force. The other method is that frequency of exciting force avoids resonance frequency of system. This paper deals with second method to reduce vibration and noise of interior permanent magnet synchronous motor (IPMSM) type ISG by changing of number of slots. Exciting force of prototype and designed model is calculated by finite element analysis (FEA) and motor´s `product-level´ and `vehicle-level´ experiment are performed to verify design method.