考虑多风电场功率相关性的概率潮流联合分布计算

Joint Distribution Calculation with Probabilistic Power Flow Considering Dependencies Among Multiple Wind Power Generations

随着大规模风电接入电网,风电的随机性为电网运行带来了更多的不确定因素,严重威胁系统的静态安全。提出一种考虑多风电场功率相关性的概率潮流联合分布计算方法,可用于评估多个风电场风电出力对系统静态安全的影响。首先采用高斯混合模型来准确描述多个风电场功率的联合概率分布,然后利用高斯混合模型的优良性质,依据系统状态量与风功率之间的近似线性关系,进而获得系统状态量的联合概率分布。将该方法应用于宁夏电网的静态安全概率评估,经过与蒙特卡罗仿真法比较,结果表明,该方法准确度更高,计算速度更快。

With large-scale wind power connected to power grid, wind generation fluctuation brings more uncertainties to power grid operation and seriously threatens power system static security. A joint distribution calculation method of probabilistic power flow considering dependencies among multiple wind power generations is proposed, which can be used to evaluate influence of wind generation on power system static security. Firstly, the Gaussian mixture model is used to characterize joint probability distribution of multiple wind power generations accurately. Then, based on excellent property of the Gaussian mixture model and approximate linear relationship between system state variables and wind power generations assumption, analytical expressions of joint probability distribution of system state variables are obtained. This method is applied to probability assessment of static security in Ningxia power grid. Compared with Monte Carlo simulation method, the proposed method has higher accuracy and faster computation speed.