An improved iron loss calculation method for high-speed induction machine fed by nonsinusoidal voltage sources

When fed by nonsinusoidal voltage sources (usual the PWM inverter), high-speed induction machine´s iron losses are a key issue since the considered frequencies are higher than usual range of the known field of magnetic material, and the existing of time harmonic components in nonsinusoidal source. Iron loss determination requests the knowledge of the flux density variation, the frequencies, and the characteristics of magnetic materials. In this paper, a simplified iron loss calculation model is proposed and experimentally verified. By using harmonic wave analysis method, the relationship between the parameters of the inverter (the voltage, the carrier wave frequency, the modulation deepness, etc.) and the flux density is analyzed, and then a neural network is developed to predict the performance of magnetic material at different frequencies. The proposed model allows calculating the iron losses of high-speed induction machine under different operation condition which takes into account the influences of harmonic effect, skin effect and saturation of magnetic material. In the paper, the description of the iron loss calculation model is reported in detail. And it is also pointed out that the model can be easily integrated with the electrical machine computer-aided design (CAD) system, which leads a useful approach for electrical machine designer