基于风电机组无功裕度预测的风电场无功分层控制策略

针对风电电压波动的问题,文章基于风电机组无功裕度预测,提出了一种风电场无功分层控制策略。该策略首先以并网点电压偏差和线路有功损耗最小为目标,使用二次规划算法在线实时求解最优并网电压,进而求解风电场无功参考值;其次,采用EWT-LSSVM预测算法进行风电功率预测,并提出预测功率校正方法实时修正预测功率,精确求解风电机组的无功裕度预测值;最后,以风电机组的出口电压波动最小和预测无功裕度最大为无功分配依据,实现风电场的无功电压闭环控制。仿真结果表明,所提控制策略能够提高风电功率预测的精确性和时效性,降低了风电机组出口电压波动性,同时为风电场预留出充足的无功裕度。

Reactive power hierarchical control strategy for wind farm based on reactive power margin prediction of wind turbines

Aiming at the problem of voltage fluctuations,this paper proposes a reactive power hierarchical control strategy for wind farm based on wind turbine reactive power margin prediction.Firstly,the minimum voltage deviation and line active power loss of the grid connection point is the cost function.The quadratic programming algorithm is used to obtain the optimal grid-connected voltage online.Therefore,the wind farm reactive power reference is obtained.Then,the wind power is predicted based on the EWT-LSSVM prediction algorithm.The predicted power correction method is proposed to correct the predicted power in real time.Thus,the predicted value of the reactive power margin of the wind turbine is accurately solved.Finally,the proposed method takes the minimum output voltage fluctuation of the wind turbine generator and the maximum predicted reactive power margin as the basis of reactive power distribution to realize the closed-loop control of the reactive power voltage of the wind farm.The simulation results show that the proposed control strategy can improve the accuracy and timeliness of wind power prediction.The output voltage fluctuation of wind turbines is reduced.The wind farm can reserve sufficient reactive power margin.