Modelling and prediction of iron loss with complex flux waveforms

The paper describes the first phase of a project to improve the prediction and modelling of iron loss for use in the design of switched-reluctance (SR) machines. Earlier models are reviewed and the development of a comprehensive model is described. Its parameters are obtained from commonly available manufacturers’ data and this allows the prediction of not only average loss but also instantaneous power flow for a given flux waveform. Its validation against experimental measurements for sinusoidal and triangular fluxes up to 2 kHz, including superimposed DC bias, is demonstrated. The measurement work using toroidal specimens reveals some unexpected behaviour and a challenge to the measurement technique.