On the modeling of dynamic hysteresis in a permanent magnet motor using transient finite-element analysis

Abstract

This paper deals with the modeling of dynamic hysteresis loops in a surface-mounted permanent magnet motor for an in-wheel electric vehicle application. In practice, a magneto dynamic vector hysteresis model has been proposed to explicitly model the magnetization behavior and the loop shapes in the studied machine. Indeed, a suitable prediction of magnetic field patterns is important for assessing its efficiency. It combines all physical phenomena including hysteretic behavior, eddy current effects and excess losses. Fundamentally, it is based on the static Preisach model used to describe the static hysteretic behavior. The Preisach model has been inverted since it is adapted in finite element solver using the magnetic vector potential as unknown. Basically, the solution is handled by means of the fixed point technique. Based on the finite element analysis results, it is shown that the height value of induction is reached in the tip of the teeth. It is equal to 1.25 T. Moreover, it is revealed that dynamic loops are predicted under rotational and distorted induction. The modeled loops include minor loops. The prediction of these coupled details proves that the adopted model is efficient and suitable for the investigation of magnetic trajectory in a rotating machine. Furthermore, it is remarkable that the convergence criterion is satisfied. This fact reveals the stability of the model.