POWER LOSSES IN MAGNETIC LAMINATIONS WITH HYSTERESIS - FINITE-ELEMENTMODELING AND EXPERIMENTAL VALIDATION

Dynamic hysteresis loop shapes and magnetic power losses are studied i n nonoriented Fe-Si laminations exhibiting significant excess losses. Measurements are carried out under controlled sinusoidal induction in the frequency range from 1 Hz to 1.6 kHz, at various peak inductions f rom 0.25 to 1.5 T. Excess losses are found to obey a integral(3/2) law up to frequencies of 200-400 Hz, depending on peak induction. Beyond this limit, definite deviations are observed, due to eddy current shie lding. Detailed information on the flux and field distribution in this high frequency regime is obtained by finite element solutions of Maxw ell equations employing the dynamic Preisach model to describe quasi-s tatic hysteresis and dynamic wall processes. The agreement between the oretical predictions and measurements is discussed. (C) 1997 American Institute of Physics.