Analysis of AC Losses in High-Speed Permanent Magnet Motors Based on the Equivalent Modeling Method

For high-speed permanent magnet motors, the AC losses and proximity effect in the parallel strands can be difficult to predict accurately. Usually, the complete 2D model is used in calculation but the modeling process is complicated and the calculation is time consuming. This paper presents an equivalent modeling method to calculate the current density distribution in the windings and AC losses in the high-speed permanent magnet motors. This method can provide accurate results and save a lot of time in terms of modeling and computation. The current density distribution calculated by the equivalent model shows a good agreement with the FEA results calculated by the complete model. This paper investigates the proximity effect and AC losses in a 100kW, 30000r/min permanent magnet motor. With the proposed method, the effect of the armature reaction magnetic field and the permanent magnet rotating magnetic field can be analyzed separately. This method can greatly improve the efficiency of high-speed motor design and optimization.