Computational methods for the evaluation of the electromagnetic losses in electrical machinery

Abstract

This paper deals with the numerical modelling of electromagnetic losses in electrical machines, using electromagnetic field computations, combined with advanced material characterisations. Due to the complexity of this objective, simplified settings, deliberately choosen by physical arguments, must be considered first. The idea is to proceed gradually to the actual problem of an electrical machine through intermediate models showing physical relevance on their own. The numerical methods used to solve these various problems mainly involve modified finite element-finite difference discretisations, which properly take into account the nonlinear and memory properties of the magnetic material. To this end, one must start from suitable variational formulations of the underlying magnetic field problems. The combined magnetodynamic-hysteresis models are validated in several ways, particularly by comparison of numerically obtained electromagnetic losses with experimental results.