计及输入变量强相关性的概率潮流计算模型

Probabilistic Load Flow Calculation Model Considering Strong Correlation between Input Variables

利用统计学的方法,以风电场出力为例,对其大量历史数据进行相关性分析,将具有强相关性的随机变量用最小二乘进行线性拟合,并用其中一个变量的线性表达式表示,从而消去随机变量之间的强相关性,并认为余下的呈弱相关或不相关的随机变量之间相互独立,以便采用半不变量法计算概率潮流。

Load flow is the basis of the steady-state analysis of the power system. However, the traditional power flow cannot be used in the system considering the uncertainty of the system. That＇s why probabilis- tic load flow comes into being. Among different kinds of methods solving probabilistic load flow, the cu- mulant method is simple and has fast calculation speed. But it requires that the input variables should be independent, so it is necessary to analyze the correlation between input variables. In this paper, the statis- tic method was applied and the outputs of different wind farms were analyzed. If they have strong correla- tion, they can be expressed with only one random variable by using the least squares. Then the rest ran- dom variable which are irrelevant or has weak correlation can be considered independent, so that the cumu- lant method can be applied.