Study on iron loss and saturation in brushless doubly-fed machines for adjustable speed drives

A time-stepping finite-element model for brushless doubly-fed machines (BDFM) is proposed in this paper. The model can readily represent the effect of saturation. In addition, it is shown that iron losses can be calculated and the saturation factors can be proposed as the time-stepping solution proceeds. The use of saturation factors in conjunction with an analytical model for BDFM is also investigated.