Cost-Efficient 2D Analysis for PM Eddy Current Loss in PMSM by Coupled A-Φ and T-Ω Method

Abstract

An eddy current of a permanent magnet (PM) used to be calculated by a 3-dimensional transient finite element analysis (3D FEA) in a conventional method. Although the 3D transient FEA brings out accurate results, it is hard to be used in the motor design because of its long computational time. Therefore, this paper proposes a cost-efficient 2D analysis to calculate the PM eddy current loss with high accuracy and low computational resource. Assuming that the flux generated by the eddy current of the PM is ignored, the flus distribution is calculated by a 2D static $\mathrm{A}-\Phi$ method on $x y$-plane. The harmonics of the flux density in the PM region are calculated. Since the time-variant of the flux density is the source of the eddy current, the flus density harmonics are reflected in a time harmonic $T-\Omega$ method to calculate the eddy current of the PM on $x z$ - and $y z$-plane. Through the proposed method, the conventional 3D FEA is replaced by multiple 2D FEAs. In addition, the static and time harmonic analyses allow the advantage in the computational time. Thus, the proposed method has advantages of high reliability and short computation. Results, such as average value of the PM eddy current loss and computational time, which is obtained on the proposed and conventional method were compared for validation.