ON A NUMERICAL-METHOD FOR THE EVALUATION OF ELECTROMAGNETIC LOSSES INELECTRIC MACHINERY

The paper deals with a numerical method for the evaluation of the magn etic iron losses in steel laminations used in rotating electric machin ery. The magnetic hysteresis and the eddy current effects are directly and simultaneously taken into account. Hereby commonly used analytic expressions for the distribution function in the widely adapted Preisa ch hysteresis model are found to be not quite accurate. The magnetic c ircuit is decomposed into magnetic and air gap network elements, conne cted by fundamental loops. The magnetic network elements show a finite element structure. The kinematics of the electric machine is delibera tely taken into account by an interpolation technique. Although the mo del retains the essential features of a cumbersome 3-D problem, a rela tively simple algorithm may be developed. For the resulting algebraic system, we propose a suitable decoupling technique, which is efficient from the computational point of view. Numerical experiments show that the results obtained by our numerical approach are in good agreement with the known behaviour of the magnetic material.