Iron loss calculation for synchronous reluctance machines

A numerical method for electric machine iron loss calculation is presented in this paper. The method is suitable for any synchronous and most DC machines, especially if the current waveforms are known a priori. This technique will be principally useful for high-speed machines and in particular for the synchronous reluctance machine, where the iron losses are often an important issue. The calculation is based on finite element analysis, which provides the flux density waveforms in the iron, and on the Fourier analysis of these waveforms. Several finite element simulations are necessary to obtain the induced voltage versus time waveforms. To reduce the post-processing time, the majority of the elements of the model are grouped together to create super elements. Also the periodicity of the motor can be used to reduce the number of required simulations. The method is applied to the calculation of the iron losses of a synchronous reluctance generator, and a number of interesting results are discussed in the paper