Improved formulations for rotational core losses in rotating electrical machines

This paper presents the measurement and modeling of rotational core losses in electrical steel sheets and rotating electrical machines. Novel formulations of rotational hysteresis, eddy current, and excess losses in electrical sheet steels with circular and elliptical rotating flux density vectors are reported. These formulations are used together with the finite element method to calculate the core losses in rotating electrical machines according to the distribution of the rotating magnetic field. Theoretical results are compared with the experiments on both electrical steel sheets and electrical machines