Finite element method analysis of the electromagnetic field of Brushless Doubly-Fed Machine

At present, structure design and performance optimization are the key points in the study of brushless doubly-fed machine (BDFM). By using ANSYS software, the finite element method (FEM) models of BDFM were established. These models have different rotor structures that are reluctance rotor with magnetic barriers, cage rotor with nested shorted-circuit windings, reluctance rotor with salient poles, and reluctance rotor with salient poles and shorted-circuit windings. As for the BDFMs of different rotor structures, the distribution of magnetic flux lines and the harmonic contents of air-gap magnetic flux were deserved by the calculation and analysis with finite element method, and the magnetic modulation effect was reflected directly, which lay the foundation for BDFM structure optimizing design.