Rotor Loss Analysis of Interior Permanent Magnet Motors Using Combination of 2-D and 3-D Finite Element Method

A novel method using combination of 2-D and 3-D finite element analyses is proposed for the rotor loss calculation of interior permanent magnet motors. First, the differential permeability at the average flux density of the rotor core is estimated by the 2-D nonlinear time-domain analysis. Then, the 3-D frequency-domain finite element analyses at each remarkable harmonic field are carried out with this permeability, in order to consider the magnetic saturation. Using this method, the calculation time is reduced to less than 1/100 compared with the full 3-D analysis, whereas the accuracy is nearly same.