The calculation of eddy current losses associated with rotating magnetic fields in thin laminations

Eddy current losses were calculated for non-oriented steel laminations subjected to an elliptically rotating flux distribution. The materials studied, a low carbon steel and a non-oriented 3% silicon steel, were described by means of a single valued non-linear initial magnetization curve. The neglect of hysteresis was due to the absence of a convenient mathematical description of two dimensional hysteresis processes. The calculational method can accommodate such a hysteresis model if it becomes available. The calculations show that the eddy current loss due to the rotating flux is given to a good approximation by the sum of the eddy current losses associated with the two unidirectional flux components (which combine to form the rotating flux) acting separately.