DFIG-Based Wind Power Conversion With Grid Power Leveling for Reduced Gusts

This paper presents a new control strategy for a grid-connected doubly fed induction generator (DFIG)-based wind energy conversion system (WECS). Control strategies for the grid side and rotor side converters placed in the rotor circuit of the DFIG are presented along with the mathematical modeling of the employed configuration of WECS. The proposed topology includes a battery energy storage system (BESS) to reduce the power fluctuations on the grid due to the varying nature and unpredictability of wind. The detailed design, sizing, and modeling of the BESS are given for the grid power leveling. Existing control strategies like the maximum power point extraction of the wind turbine, unity power factor operation of the DFIG are also addressed along with the proposed strategy of "grid power leveling." An analysis ismade in terms of the active power sharing between the DFIG and the grid taking into account the power stored or discharged by the BESS, depending on the available wind energy. The proposed strategy is then simulated in MATLAB-SIMULINK and the developed model is used to predict the behavior. An effort is made to make the work contemporary and unique, compared to the existing literature related to issues governing grid fed DFIG-based WECS.