基于综合Copula函数的风电出力相关性建模

针对单一Copula函数模型在描述风电功率相关性中失真较大的缺陷,提出构造综合Copula函数模型刻画其相关结构的策略,并采用EM方法估计模型中相关参数的值。以某地区两相邻风电场的实际历史出力数据为基础,通过对比不同组合函数的拟合优度校验,筛选出最优的综合Copula函数,并将其运用于系统的概率潮流计算中,作出支路有功功率及节点电压这二者的概率密度曲线,通过与单一Copula函数所得曲线的对比,验证了其在风电场出力建模中的有效性及可行性。

Modeling of wind farm power correlation based on comprehensive Copula

In view of the model of single Copula function containing larger distortion defects in describing wind power correlation, a strategy of comprehensive Copula function model is put forward to depict the correlation structure, and EM method is used to estimate the value of the related parameters in the model.Two adjacent wind farms in a certain area of actual historical output data as the foundation, by comparing different combination functions of goodness of fit check, we select the most optimal comprehensive Copula function, and apply it in the probabilistic power flow calcula-tion of the system.The two probability density curve of the branch active power and the node voltage is made.By comparing with single Copula function of income curve, the effectiveness and feasibility are verified in modeling of wind farm output.