Computation of magnetic fields in media with hysteresis.

摘要

A new method for computation of magnetic fields in media with hysteresis, which is based on new mathematical models of the hysteresis phenomenon, is developed. The main advantages of this method over the previously reported ones is that the new hysteresis models are more precise and numerically efficient compared to the conventionally used models. The method of field computation is based on the time-stepping approach, according to which a magnetostatic problem with hysteresis is formulated approximately as a sequence of magnetostatic problems with single-valued constitutive laws obtained from the hysteresis model. Each magnetostatic problem in this sequence is reduced to the magnetization integral equation and solved using an iterative technique.;The vector Preisach hysteresis model, suggested by I. D. Mayergoyz, is employed for the description of hysteretic media. This model is investigated and the identification problem of fitting this model to experimental data is discussed. It is found that this model is better suited for computations of the magnetic field than the classical Stoner-Wohlfarth model because it describes nonsymmetrical minor hysteresis loops and requires less integration for its numerical implementation.;A new scalar hysteresis model, which is more general than the classical Preisach model, is developed. An efficient numerical implementation of this model is proposed and the accuracy of the model is tested experimentally. The accuracy of the new model is found to be superior to the accuracy of the classical Preisach model.;Digital computer codes for the implementation of the classical, vector and generalized Preisach models are developed. The vector model code is used as a subroutine in the code for the magnetic field computation. The discussed theory is illustrated by numerical examples.