基于随机预测理论的双馈风电机组参与电网调频控制策略

Frequency Regulation Control Strategy of DFIG Participating in Power Grid Based on Stochastic Prediction Theory

随着电力系统中的风电渗透率不断提高,系统中风电功率的随机波动给电网频率稳定性带来巨大挑战。针对上述问题,该文提出基于机会约束随机模型预测控制的附加功率调频控制策略。首先,综合考虑系统中风速及负荷的实时随机波动问题,建立风电并网系统频率响应模型;其次,以系统频率变化及风电输出功率波动最小为控制目标建立期望目标函数,并将机会约束纳入随机最优化模型中;最后,根据随机扰动的分布信息或坎泰利不等式,结合状态反馈控制律求解随机最优化模型,得到当前时刻的最优控制律。利用MATLAB/Simulink搭建风电并网系统进行仿真验证,结果表明,所提策略能够有效抑制风电功率波动及系统频率变化,提高了电网的频率稳定性。

With the increasing penetration of wind power in power system,the random fluctuation of power and load brings great challenges to the frequency stability of power grid.To solve the above problems,this paper proposes a frequency regulation strategy based on chance constrained stochastic model predictive control.First,the frequency response model of wind power grid-connected system is established by considering the real-time random fluctuation of wind speed and load.Then,the desired objective function is established to minimize the system frequency variation and wind power fluctuation,and the chance constraint is incorporated into the stochastic optimization model.Finally,according to the distribution information of random disturbance or cantelli inequality,and combined with the state feedback control law to solve the stochastic optimization model,the optimal control law at the current moment is obtained.A detailed wind power grid-connected system model is built in MATLAB/Simulink for simulation verification.The results show that the proposed strategy can effectively suppress wind power fluctuations and system frequency changes,and improve the frequency stability of power grid.