Loss Analysis of a Reactor under Inverter Power Supply Taking Account of Anomalous Eddy Current Loss

Abstract

To reduce the iron losses of reactors under inverter power supply, the loss was calculated by using magnetic field analysis, which models a laminated core by combining a 3D solid-core model with a 1D steel plate model, using the finite element method (FEM). In this method, the structure of the laminations and the eddy currents in the steel plates can be taken into account. However, for reactors driven by inverter power supply, the calculated iron losses are much smaller than the measured results, because the anomalous eddy current loss induced by domain wall motion in the steel plates is neglected in the loss calculation. Therefore, this paper investigates a simple numeric modelling method that takes account of the anomalous eddy current loss by modifying the conductivity of the steel plates. First, the method is verified by comparing the calculated iron loss of one sheet of steel plate with the measured data. The method is then applied to the loss calculation of reactors under inverter power supply. The differences between the calculated and measured results become smaller when the anomalous eddy current loss in the steel plates is taken into account.