Abstract:To solve the torsional vibration problem of permanent magnet synchronous motor (PMSM) which causes the body structure vibration and noise in electric vehicle, firstly, non-linear dynamical model of torsional vibration of PMSM was established with the lumped parameter method and the electromagnetic Torque of PMSM considering non-sinusoidal magnetic field distribution of permanent magnet, slotting and harmonic currents was obtained by an analytical method. Stiffness and damping parameters were obtained as well. It was indicated that electromagnetic torque ripple is the main reason of the torsional vibration of PMSM. Then, the non-linear differential equations were solved by means of the solved State variable technique. Finally, the model was tested and verified by the experimental results.