基于随机响应面法的含风电电力系统小扰动稳定性分析

风力发电的不确定性对电力系统小扰动稳定性造成一定影响,而地理位置相近的风电场间的风速具有一定的相关性。本文建立双馈风电机组的动态模型,利用Nataf变换建立考虑风速相关性的风电场群模型,运用随机响应面法(SRSM),以风速作为输入,系统特征值、阻尼比、频率作为输出,分析了系统的小扰动稳定性,同时应用基于线性无关原则的概率配点选取法,合理选择有效配点,提高了SRSM的计算效率。在10机39节点系统中将SRSM与蒙特卡罗法比较,结果显示SRSM计算结果准确可靠,计算时间远远少于蒙特卡罗法的计算时间,能够实现系统小扰动稳定性分析的快速评估。在是否考虑风速相关性两种情况下进行对比,结果表明:考虑风速相关性时系统小扰动分析结果的波动更小,对系统安全稳定运行具有更明确的指导意义。

Small Disturbance Stability Analysis of Power System Containing Wind Power Based on Stochastic Response Surface Method

The uncertainty of wind power has effect on small disturbance stability of power system, and the wind speed of wind farm with near geographical position has a certain correlation. This paper established the dynamic model of doubly fed induction generator (DFIG), a wind farm cluster model considering wind speed correlation is established by using Nataf transform. Using stochastic response surface method (SRSM), taking wind speed as input, eigenvalues, damping ratio and frequency of system as output, the small disturbance stability is analysized. At the same time, probability distribution point selection method based on linear independent principle is used to choose the effective distribution point, which improves the computational efficiency of SRSM. In the 10 machine 39 bus system, comparing SRSM with Monte Carlo method, the results show that the SRSM calculation results are precise and reliable, the computation time is far less than the Monte Carlo computation time, and can realize the rapid assessment of the small disturbance stability analysis of power systems. Whether considering the correlation of wind speeds were compared. Results show that considering the correlation of wind speed has smaller fluctuation of the small disturbance analysis result, which has a more clear guiding significance for the safe and stable operation of power system.