计及发电功率相关性的静态电压稳定概率评估方法

Evaluation Method for Static Voltage Stability Probability Considering Correlation of Generated Power

针对风力、光伏发电出力的随机性和相关性,提出了计及发电功率相关性的静态电压稳定概率评估方法。基于拉丁超立方采样结合Cholesky分解建立满足相关性要求的风速、光照辐照度的概率分布模型,引入含随机发电功率的扩展潮流方程并求取电压稳定裕度。IEEE 118节点测试系统的算例仿真验证了所提方法能够在保证精度的前提下有效地提高计算效率,且能够方便地计及输入随机变量之间的相关性。算例结果同时表明,发电功率的相关性将加强电压稳定裕度概率分布的波动性,导致电压稳定裕度处于低值的概率增大。

In allusion to random and correlation of wind power and photovoltaic power generated output, an evaluation meth- od for static voltage stability probability considering correlation of generated power was proposed. Probability distribution models for wind speed and light irradiance were established based on Latin hypercube sampling combing with Cholesky de- composition which might meet requirements for correlation. Extended power flow equation with random generated powcr was introduced to get voltage stability margin （VSM）. Example simulation of IEEE 118 node testing system verifies that the referred method could effectively improve calculation efficiency on the premise of ensuring precision as well as conveniently consider correlation of random variables. Meanwhile, example results indicate that correlation of generated power would strengthen fluctuation of VSM probability distribution which may cause increase of probability of low-valued VSM.