Coordinated Reactive Power Compensation Strategy for DFIG Wind Farm with STATCOM

Doubly fed induction generator (DFIG) can be involved in the system reactive power regulation, but the function of reactive power compensation is limited. In order to realize the constant power factor operation mode of DFIG, it still needs coordinated reactive power compensation among multiple reactive power compensation devices (such as fixed capacitors/FACTS devices). According to different compensation characteristics of reactive power compensation devices, a coordinated reactive power compensation strategy with STATCOM is proposed, which is applicable to solve such problem as coordinated reactive power compensation between STATCOM and fixed capacitors during the wind speed fluctuations. The basic theory is that required reactive power reference value of wind farm is set flexibly through the closed loop feedback according to PCC voltage, the reference value of different buses is distributed according to its voltage deviation to bus bar, and the hysteresis control strategy is applied to realize coordination control among reactive power compensation devices. The simulation results in the PSCAD/EMTDC environment show that the proposed coordinated strategy has a good compensation effect both in the transient and steady state conditions.