Indirect Stator-Quantities Control for the Brushless Doubly Fed Induction Machine

The brushless doubly fed induction machine (BDFIM) shows potential in replacing the wound rotor machines for certain industrial applications due to its higher reliability, a benefit of the absence of brush gears. This paper proposes an indirect stator-quantities control (ISC) strategy for the BDFIM. Theoretical derivation has been carried out to demonstrate the control principle for the proposed strategy. ISC provides the benefit of a simple structure, since it is implemented in two static reference frames and no rotating coordinate transformation is required. Furthermore, only two stator winding resistances are used, and therefore, the controller structure is less dependent on machine parameters. The experimental results of the prototype show the feasibility of the proposed strategy for the BDFIM.