An Accurate Core Loss Model of Inverter-Fed Induction Machine Considering Supply and Saturation Harmonics

Abstract

This article presents a novel mathematical model for accurately predicting the net core loss of inverter-fed induction machines (IMs). Rotating field waves generated by all the sources such as permeance variations, source harmonics, and magnetic saturation are derived using the material characteristics. Analytical expressions for additional surface core loss and pulsation losses generated by the saturation as well as the losses incurred by augmented teeth flux densities with leakage fluxes are derived. For accurate estimation of these losses, instantaneous filed densities in various iron segments at different loading conditions are determined with on-load magnetizing current in inverter-fed operation, calculated using time-domain variation of magnetizing inductance with flux linkage. Magnitudes of saturation caused field waves are then determined iteratively using the iron magnetization profile. The accuracy of the loss model is validated by comparing the measured and simulated core loss of 11 kW IM under no-load and on-load conditions. In the pursuit of achieving net-zero carbon emissions, advancing transportation electrification stands as a crucial milestone, necessitating the utilization of traction motors tailored. As such, a precise iron core loss model is proposed, capable of effectively accounting for frequency-dependent impacts in forecasting no-load and on-load core loss.