A 3D electric vector potential formulation for dynamic hysteresis and losses

Abstract

Purpose -The purpose of this paper is to introduce the dynamic hysteresis and losses of soft magnetic materials in numerical computation of high-sensitive devices. Design/methodology/approach -So as to do this, the authors propose to lump all the microscopic dynamic effects due to averaging and smoothing techniques that lead to the definition of a dynamic field as proposed by other contributions. In this paper, the method to implement the modified field diffusion process in finite element computations is investigated, explained, detailed and put to the test. Findings -In order to take microscopic magnetization reversal processes and eddy currents that damp the field at the mesoscopic scale, the authors have been led to define a new dynamic property L representative of the magnetic structure and its easiness to change. It is involved in an additional term in both the magnetic behaviour law and the bulk and surface coupling formulations describing the physical problem in iron and at the borders. Research limitations/implications -This model can only be used for macroscopic pieces for which each dimension is bigger than at least four times the characteristic length of magnetic domains. Originality/value -The originality of the paper comes from the need to investigate the possibility to predict iron losses and the corresponding dynamic hysteresis during the processing computation of power electrical devices such as accurate sensors and high-sensitive actuators of earth leakage circuit breaker for example.