Core Loss Prediction in Electrical Machine Laminations Considering Skin Effect and Minor Hysteresis Loops

This paper presents a method for the estimation of core losses in electrical machine laminations exposed to high-frequency and nonsinusoidal excitations by using only low-frequency measurements. The developed model takes into account the nonuniform distribution of the magnetic field inside the lamination. Accurate core loss prediction in the presence of minor loops is achieved using the energetic model to calculate the quasi-static hysteresis loops. The results are verified experimentally by comparing to the measured core losses in laminations exposed to the flux waveforms in different sections of an inset permanent magnet machine. The comparison between measured and calculated core losses shows excellent agreement, confirming the validity of the model.