Core losses estimation of high speed electrical machines based on corrections in epstein frame method data

With the advantages in high power density and gearless drive train, high speed machines have been employed in many applications today. It is critical to have accurate estimation of core losses under high frequency and non-sinusoidal magnetic excitation at the initial design stage. Since most core losses measurements are based on Epstein Frame Method, the data tend to be over-measured due to overlapped stacking laminates at four corners of test samples. The cornering effects are significant and must be accounted if the laminates are operated under high excitation frequency. A revised core losses estimation scheme based on the data from Epstein Frame Method is studied. Cornering effects in Epstein Frame data are verified by making use of ANSYS EM simulations. Finally, design cases of a high speed machine are illustrated for comparisons and discussions.