A Comprehensive Analysis of Electromagnetic NVH in Electric Powertrain

In this paper, a comprehensive analysis of NVH in electric powertrains due to electromagnetic sources is presented. The spatial harmonics model of the traction motor, which is dependent on the motor design structure, rotor poles, stator teeth, and slots, is used for the analysis of the electromagnetic forces from the motor in the electric powertrain. The time harmonics model of the injected current of the motor dependent on the drive electrical circuit and control strategy is also considered for the electromagnetic force calculation. A complete workflow of this electromagnetic NVH analysis for electric powertrain covering the spatial harmonics and time harmonics model is presented. The spatial harmonics model result is presented as flux linkage with respect to dq-axes current and rotor position. The time harmonics are also presented by the injected current of the motor. In addition, a set of operating points on the torque-speed boundary of the traction motor is selected and results are applied in the NVH analysis. As a result, the finite element simulation and the comparison of different noise levels demonstrate the capability of this method and lay the basis for future electromagnetic NVH performance optimization.