Magnetostatic Modeling of Brushless Doubly Fed Reluctance Generator: Comparison and Validation

The brushless doubly fed reluctance machine (BDFRM) is a type of electric machine with two independent stator windings and a passive reluctance rotor. In the literature, it is often proposed as a good alternative for wind turbine generators, especially where high reliability is important. Its benefits include the use of a partially rated converter, the absence of permanent magnets, brushless operation, and variable-speed operation with direct grid connection. This article proposes a magnetostaticdq-modeling approach for the BDFRM under both DC- and AC-excited control winding conditions. The modeling is performed using an in-house magnetostatic finite element solver, which employs iterative solving with frozen permeability to achieve fast, accurate, and robust computation at specified operating points. The modeling is validated against experimental data from a grid-tiedBDFRMprototype operating at various power factors. By reducing computational demands and using an iterative solution approach, this method enables more efficient and robust design optimization under specified operating conditions. Additionally, the use of frozen permeability also provides valuable insight into the machine’s complex inductance behaviour.