Predicting iron losses in soft magnetic materials with arbitrary voltage supply: an engineering approach

TLDR

The study proposes a method to predict iron losses in soft magnetic materials for any voltage supply based on known losses from sinusoidal or PWM supplies. The approach models iron losses by separating hysteresis, eddy current, and excess components and deriving a mathematical relationship between each loss contribution and the voltage supply characteristics, using material‑dependent coefficients. The model accurately predicts iron losses for various magnetic materials and voltage supplies, yielding material‑specific coefficients that aid designers in evaluating performance under non‑sinusoidal conditions.

Abstract

We propose a new approach for predicting iron losses in soft magnetic materials with any voltage supply, starting from the knowledge of the iron losses with a sinusoidal or pulsewidth modulation supply. The model is based on the separation of the loss contributions due to hysteresis, eddy currents, and excess losses with the two supplies. Since any contribution depends on the voltage supply characteristics, it is possible to find a direct mathematical relationship between the iron loss contribution and the voltage supply characteristics. As a consequence, an iron loss prediction can be obtained with any voltage supply if it does not produce a hysteresis minor loop. The energetic model is based on coefficients that depend on the magnetic material characteristic. We performed an accurate analysis of the model on eight magnetic materials used for electrical machine construction, of different thicknesses and alloy compositions. In this way, we found the main coefficients for a large spread of magnetic materials. As a consequence, our approach can be a useful support for electrical machine designers when the energetic performance of a magnetic material has to be predicted for a voltage supply different from the sinusoidal one.