Electromagnetic and vibrational characteristic of IPM over full torque-speed range

This paper investigates the electromagnetic and vibrational characteristic of an interior permanent magnet machine (IPM) over the entire torque-speed range based on the model of 2004 Toyota Prius IPM motor. First, the dominant electromagnetic radial force directly causing vibration is calculated based on optimal operating plane, which covered by maximum torque per ampere (MTPA), current limit curve, and maximum torque per volt (MTPV) curve. Next, vibration behavior of the stator is studied by using modal and structural analysis in ANSYS workbench environment. It is observed that electric vehicle (EV) application deserves closer attention as more resonant vibration points may appear. To simultaneously meet the efficiency and NVH (noise vibration and harshness) requirements the pole-slot number and control strategy should be carefully chosen.