Reduced-order Frequency Response Model for DFIG-based Wind Farm With Power Support

With the increase of wind power penetration and the participation of wind farm in frequency regulation, it is necessary to construct an accurate and efficient frequency response model of the wind farm for coping with the frequency related issues. This paper proposes a reduced-order frequency response model for doubly fed induction generator (DFIG)-based wind farms that participate in the system frequency regulation. Firstly, to avoid measurement error of the wind speed in open-loop control mode, a frequency response model of the DFIG based on closed-loop feedback control mode is constructed by linearization method, which involves the dynamic properties of the rotating part and the control unit of the DFIG. Then, based on the single DFIG model, the reduced-order frequency response model of the wind farm is derived by the balanced truncation (BT) algorithm. The reduced-order model is competent for the scenarios where the DFIGs operate in various states in the wind farm, as well as has a low computational burden. The effectiveness of the reduced-order frequency response model of the wind farm is verified through comparisons with the simulation result.