基于蒙特卡罗抽样半不变量法的微电网随机潮流计算

摘要

To improve the calculation accuracy of probabilistic load flow in microgrid,a combination of Monte Carlo simulation and Cumulant method is proposed. First,the liner model of probabilistic load flow is established,then Monte Carlo sampling method and conventional numerical method are used to calculate each cumulant of the probabilistic vari⁃able. Second,the cumulant of the node state variables and branch current is calculated,and it is further resolved by Gram-Charlier expansions. Finally,the probability distribution of cumulant is obtained. A case study shows that com⁃pared with Monte Carlo simulation,the proposed method is reliable and rapid,which can provide reference for electrical dispatching.%为了提高微电网随机潮流计算的精度，提出了将蒙特卡罗抽样和半不变量法相结合的方法。首先建立了微电网随机潮流的线性化模型，然后运用蒙特卡罗抽样法和常规数值法计算随机变量的各阶半不变量，进而计算节点状态变量和支路潮流的半不变量，并运用Gram-Charlier级数将其展开，最终得到半不变量的概率分布。将该方法与蒙特卡罗模拟法比较，算例表明该方法具有较高的准确性和快速性，可为电力调度提供可靠依据。