Decoupled control of doubly fed induction generator for wind power system
Wind power, as an important and promising renewable resource, is widely studied. Recently, doubly fed induction generator (DFIG) becomes more popular in wind power due to its various advantages over other types of wind turbines, such as variable speed, lower power electronic cost and so on. However, the back-to-back converters require effective and accurate control to accommodate the complexity of power system operation. In this paper, first of all, a dynamic model of DFIG-based wind power system is derived in complex form. Based on the dynamic model, a complete control strategy is presented to control the rotor-side converter and grid-side converter, respectively. A decoupled control method, which is capable of separating d-axis and q-axis components of rotor current, is applied to harness wind power. The concept of instantaneous power is introduced to regulate DC-link voltage. The control strategy is tested in RTDS/RSCAD. The effectiveness of the proposed method is verified by the simulation results.