Iron loss estimation method for general hysteresis loop with minor loops

In order to design highly-efficient electrical machines, it is necessary to estimate their iron losses accurately. The conventional iron loss estimation method estimates iron loss based on the assumption that eddy current loss coefficient (k_e) and hysteresis loss coefficient (k_h) under non-sinusoidal excitation are equal to k_e and k_h under sinusoidal excitation. However, these coefficients are not identical because minor loops are not centered but on ascending and descending major hysteretic curves. In this paper, we verify whether k_e under dc-biased excitation is equal to k_e under sinusoidal excitation. In addition, the method of analyzing iron loss under non-sinusoidal excitation using dc-biased magnetic properties is proposed.