考虑风电相关性的电力系统随机无功备用优化

Abstract

针对目前无功备用评估方式的缺陷和以风电为代表的新能源大量接入之后节点注入功率的不确定性,提出一种新的无功备用评估方法,并在此基础上建立考虑风电相关性的随机无功备用优化模型。首先使用均匀抽样法获得服从均匀分布的样本,然后使用基于奇异值分解的Nataf变换获得含相关性的风速样本,采用蒙特卡洛法将机会约束转化为确定型约束并采用混合蛙跳算法求解。数值计算的结果验证了所提无功备用评估方法的有效性,进一步分析表明风电会恶化系统的运行环境,增加状态变量越限的概率,而所提方法可以有效提高系统的电压水平和电压稳定裕度,降低系统的运行风险,并对N-1严重故障也有一定的改善效果。

Aiming at the deficiency of present reactive power reserve assessment and the uncertainty of node injection power due to the large-scale integration of renewable energies, represented by wind power, a method is proposed for the reactive power reserve assessment, based on which, a stochastic reactive power reserve optimization model considering the wind power correlation is built. The uniform sampling method is used to obtain the samples with uniform distribution, the Nataf transformation based on singular value decomposition is adopted to obtain the wind speed samples with correlation, the Monte Carlo method is applied to convert the chance constraints into the definitive constraints, and the SFLA (Shuffled Frog Leaping Algorithm) is adopted to obtain the solution. The results of numerical calculation show the effectiveness of the proposed method, and the further analysis shows that, the wind power may deteriorate the operational environment of system and increase the limit violation probability of state variable, while the proposed method can effectively improve the voltage level and voltage stability margin of system, decrease its operational risk and mitigate the N-1 serious fault in a certain degree.