A NEW APPROACH TO CALCULATING CORE LOSSES IN THE SRM

In the switched reluctance motors, the flux waveforms are nonsinusoida l and different parts of the magnetic circuit have different waveforms , This paper presents a new approach to taking into account these flux waveforms in the calculation of core losses, Relations between the fl uxes of different parts of the magnetic circuits are given in the form of matrix equations, where the fluxes are expressed in terms of norma lized flux pulses, Rewriting the eddy-current loss term in the Steinme tz equation in terms of the square of dB/dt and combining it with the matrix equations, eddy-current losses for the complicated flux wavefor ms of the stator and rotor yokes are calculated, The effect of PWM is taken into account by considering the PWM voltage waveform as dB/dt. F rom the matrices, it is easy to count how many times the full and mino r hysteresis loops occur at each pole and yoke segment. The effect of the minor loop is taken into account based on experimental results, Th e proposed approach gives a systematic procedure for the core loss cal culation. The derived equations are simple and useful for the design o f the SRM.