Priority List-Based Output-Restricted Active Power Control Strategy for Wind Farms

With the rapid increase of grid-integrated capacity of wind farms,wind farms should possess the adjusting ability of active power that can control active power output of wind farm according to the command from control center of power grid.Combining with actual requirement for active power control system of clustered wind farms in Jiuquan wind power base in Gansu province,China,taking the utilization of wind energy farthest and the prevention of frequent start/stop of wind power generators as the objectives and based on classical priority list method,an output-restricted active power control strategy for wind farms composed of variable speed constant frequency(VSCF) wind power generators is proposed.To meet the demand on output-restricted control for wind farms,an active power control frame in the level of wind farm and corresponding output-restricted control process are designed.Overall considering the prediction information,operating conditions and control characteristics of wind power generation units within wind farms,an output-restricted active power control sequence for wind farms,in which the indices of control performances of wind power generation units are taken as the index for rank ordering,is established,and then,based on the control sequence the method to allocate output-restricted active power is given.The correctness and effectiveness of the proposed control strategy are verified by the calculation of a wind farm composed of 33 doubly fed induction generators.