Abstract: The main vibration of interior permanent magnet synchronous motor（IPMSM）with integer slot multipole pair for electric vehicles is the vibration at 0-order and 2p-order natural frequencies, which are generally believed to be caused by the spatial electromagnetic force waves of 0-order and 2p-order. In order to study the contribution of high-order electromagnetic force waves to these two vibrations, a unit force wave harmonic response analysis method was proposed to analyze the contribution of higher-order electromagnetic force wave to the vibration of IPMSM with integer slot multi-pole pair for electric vehicles. Taking a 48 slot 8-pole IPMSM for electric vehicle as an example,firstly, the harmonic source of high-order spatial electromagnetic force wave was analyzed theoretically, and then the finite element simulation model of the prototype was established to analyze the influence of each high-order force wave on the vibration at 0-order and 8-order natural frequencies. The results show that 48-order and 40-order spatial electromagnetic force waves have great contribution to the vibration at 0-order and 8-order natural frequencies respectively. The experimental results verify the correctness of the simulationmodel and theoretical analysis.

      Key words: electric vehicles IPMSM；high-order electromagnetic force wave；unit force wave harmonic

response analysis；vibration