Analysis of Rotational Hysteresis Property in a Transformer Core Based on an Inverse Jiles-Atherton Hysteresis Model Coupled with Finite Element Method

It has been indicated experimentally that the rotational loss in a silicon steel is obviously greater than alternating one. It is significant for the optimal design of transformers and electrical machines to establish an accurate hysteresis model to estimate the rotational loss. An inverse vector Jiles-Atherton hysteresis model with variable coefficients is proposed in this paper. These two coefficients are reversible magnetization coefficient and irreversible magnetization coefficient, respectively. The finite element calculation when coupled with proposed hysteresis model is derived. And the effectiveness of this proposed model is validated by comparing with the experimentally measured results and also applied to solve the magnetic field over a motor core model.

I. Introduction

Magnetic performances of transformers, motors and other electrical equipment are affected by many factors in the working process [1],[2], and one of the most important factors is relevant with magnetic hysteresis characteristics of ferromagnetic materials [3]. The researches have indicated that the trajectory of magnetic flux density vector within one excitation period at the T-joint part of transformer cores or the stator core of motors is can be approximated as elliptic or circular [4]. The E&S model is considered as a relatively accurate estimation model to describe the characteristics of rotating magnetism [5], [6]. But the E&S model does not give a specific physical explanation of the magnetization mechanism, which requires a large number of experimental measurement data during the parameter identification and is not suitable for engineering application.