光伏发电系统对配电网三相电压不平衡度影响的计算方法  

The calculation method for influence of photovoltaic power generation system on three-phase voltage unbalance degree of distribution network

作　　者：陈伟[1] 倪源宏 纪青春 王忠飞 何峰 CHEN Wei;NI Yuan-hong;JI Qing-chun;WANG Zhong-fei;HE Feng(School of Electrical and Information Engineering,Lanzhou Univ.of Tech.,Lanzhou 730050,China;State Grid Gansu Power Company Lanzhou Power Supply Company,Lanzhou 730050,China)

机构地区：[1]兰州理工大学电气工程与信息工程学院,甘肃兰州730050 [2]国网甘肃省电力公司兰州供电公司,甘肃兰州730050

出　　处：《兰州理工大学学报》2023年第2期76-82,共7页Journal of Lanzhou University of Technology

基　　金：国网甘肃省电力公司科技项目(SGGSLZ00FCJS2000712)的资助

摘　　要：针对传统确定性潮流计算在对分布式光伏电站接入配电网后导致的三相电压不平衡现象进行评估时的不足,提出了一种基于多点线性化的半不变量概率潮流和重要抽样对配电网不平衡度进行评估的方法.首先,针对Beta分布描述的局限性,以自适应非参数核密度估计法对光伏出力和负荷波动的随机过程进行表征,从而提高建模精度;然后,利用分段线性化半不变量法进行随机潮流分析以降低不确定性引起的误差,构建出混合Copula函数计算公共连接点的不平衡度;最后,采取抽样方法得到不平衡度均值进行评估.通过对IEEE33节点系统进行仿真分析,验证了此方法的有效性和可行性.Aiming at the deficiency of traditional deterministic power flow calculation in the evaluation of three-phase voltage unbalance caused by distributed photovoltaic power stations connected to the distribution network,a method based on multi-point linearization semi-invariant probabilistic power flow and importance sampling was proposed to evaluate the unbalance degree of distribution network.First,given the limitations of the Beta distribution,the adaptive nonparametric kernel density estimation method was adopted to characterize the photovoltaic output and load fluctuation random process to improve the modeling accuracy,and then the method of piecewise linearization semi-invariant was used to perform stochastic trend analysis to reduce the error due to uncertainty.Afterward,the mixed Copulas connect function was constructed to calculate the unbalance of the public connection point.Finally,the sampling method was used to get the mean value of unbalance degree for evaluation.In the end,the effectiveness of the proposed method was verified by the simulation analysis of the IEEE33 node system.

关 键 词：三相电压不平衡度 概率潮流 核密度估计 半不变量法 M-Copula函数 

分 类 号：TM711[电气工程—电力系统及自动化]