Comparative study of DFIG power control using stator-voltage and stator-flux oriented frames

This paper compares real and reactive power control for a DFIG (doubly-fed induction generator) based wind turbine system using stator-voltage and stator-flux oriented frames. The paper presents DFIG steady-state and transient models in d-q reference frame. The steady-state model is used to obtain the general relationship between the rotor d/q current and stator real/reactive power references using stator-flux and stator-voltage oriented frames. The transient model, together with the analysis based on DFIG steady-state d-q equivalent circuit, is used to develop DFIG power control mechanisms. In the evaluation of DFIG controllers, the wind turbine driving torque is modeled by considering typical wind turbine aerodynamic characteristics under variable wind and pitch angle conditions. Comparisons are made to evaluate the theoretical difference of the DFIG controllers using stator-voltage and stator-flux oriented frames. Simulation results for a 2 MW DFIG system demonstrate the performance of the controllers for variable wind speed and active and reactive power references.