Brushless Doubly Fed Machine Design Evaluation With Power Factor Considerations

In this paper, it is proposed that design evaluations of brushless doubly fed machines (BDFMs) be conducted at unity power factor in the synchronous generating mode, for wind turbine applications. In the build up to this idea, differences in power output at asynchronous, synchronous motoring, and synchronous generating modes are highlighted and discussed. The changes in generated power at varying grid side power factor of BDFMs are also demonstrated. Different designs of doubly fed induction generators (DFIGs) and BDFMs are simulated to highlight these variations. Potential issues that can arise from insufficient design evaluations are discussed. Experimental measurements from a 160 L frame 2/3 BDFM are also used for validation.