Decoupled feed-forward control model enhancement for low voltage ride through capability in DFIG-based wind turbines

Doubly fed induction generator (DFIG) is significantly affected by various faults occurring in the grid as they are directly connected to the grid. In order to realize the low voltage ride through (LVRT) capability, the DFIG must remain connected to the system for a certain period of time according to the grid code requirement. In order to achieve this, the high rotor current must be reduced in DFIG against faults occurring on the grid side. In this study, a decoupled feed-forward control model was developed for the LVRT capability. Positive, negative, natural, and forced methods were used for the decoupled feed-forward control (FFC) model. In addition to this developed model, while the stator electromotive force (EMF) model was developed for simulation study performance and ease of calculation, the rotor EMF model was also developed to predict the transient rotor current quickly. The developed models and the conventional model were used and compared in detail. According to the results obtained, it was observed that the system became stable owing to the developed model, while the oscillations formed as a result of the transient stability were damped.