Modeling of iron losses in an induction machine based on a magnetic equivalent circuit in Modelica

Abstract

Finite element methods (FEM) allow estimating iron core losses including saturation effects in electric machines. Nevertheless, the analysis is computationally intense and not reflecting hysteresis behavior correctly. This work presents a 1D magnetic equivalent circuit (MEC) modeling approach for an induction machine, which allows performing accurate calculations of iron losses in the laminated core. This offers to consider spatial dependencies like in FEM, but with less computational effort. The developed magnetic non-linear lumped circuit elements (i.e. permeances) of the laminated iron core are specialized for pulsed operation. This enables to consider saturation- and hysteresis effects correctly. The proposed approach is implemented in Modelica; the model setup and the simulations are performed in Dymola. The validation of the developed 1D approach with FEM points out, that the MEC model is capable of estimating static and dynamic hysteresis losses during the electromagnetic energy conversion processes in the core lamination of an induction machine correctly.