电网限负荷条件下风电场一次调频策略

Primary Frequency Control Strategy for Wind Farms Under Output-Restricted Condition

随着风电并网容量的增加,电力系统的调频、调峰问题日益突出,这就要求风电场应具备功率调节和频率调整的综合控制能力。根据风电机组的风速状况提出超速控制和桨距角控制协调的减载控制方案,使得预留的功率既可满足风电场的限负荷控制要求,也可作为风电场的调频备用。同时,根据风电场自身的运行状况整定风电机组的静态调差系数,并结合风场的功率分配策略,使风电场能在电网限负荷条件下尽可能地支持电力系统的频率调整。仿真结果表明,所提出的方法能满足电网限负荷指令,改善系统的调频特性,并缓解常规发电厂的调频压力,充分利用限负荷条件下的"弃风"资源。

With continuous increase of wind power capacity integrated to grid, frequency events and peak shaving problems are becoming increasingly prominent. It is very important for wind farms to possess comprehensive ability of active power and frequency controls. Aiming at this issue, a de-loading control scheme coordinating over-speed and pitch angel controls of wind turbines based on wind speed conditions is proposed. Therefore, the de-loaded power can not only satisfy limited load demand from power grid, but can also be reserved for primary frequency control（PFC）. A method is put forward to calculate droop value of wind turbines, a critical parameter of frequency regulation, according to wind farms＇ operating conditions. Combined with active power dispatch strategy of wind farms and droop value calculation method, wind turbines under different wind speeds can support frequency regulation as much as possible. Simulation results show that the proposed strategy could meet grid load command, improve PFC performance, alleviate frequency regulation pressure of conventional power plants, and make full use of reserved wind energy.