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.. 基于半不变量法的随机潮流计算 摘要 电力系统运行中存在大量的不确定因素，如负荷波动、发电机故障停运及输电元件故障等等。一般的潮流计算不但计算量很大而且很难反映全面的情况。概率潮流计算运用了概率统计方法处理系统运行中的随机变化因素，并且得出了和实际情况相近的随机出现的概率值。 首先，本文介绍了概率潮流的计算模型，包括发电机的概率模型、负荷的概率模型和线性化的交流模型。其中发电机的出力服从二项概率分布,负荷的功率服从正态分布。 然后，介绍了随机潮流的基本概念，半不变量随机潮流的计算方法，半不变量的概念和Cham-charlier 级数。 最后，本文用半不变量随机潮流算法的步骤，结合Gram-Charlier 级数展开式，计算随机变量的分布，得到节点电压概率密度函数。本文中采用MATLAB语言编写程序算法，用IEEE14 节点系统进行随机潮流的计算，并进行了算例分析。结果表明，本文的算法是切实可行的。 关键词：电力系统；随机潮流；半不变量；Gram-Charlier 级数 Probabilistic load flow computation based on Cumulant Abstract There are many uncertain factors in power system operation, such as the failure of generator outage and load fluctuation, transmission component failure etc.. The general trend needs much computation and is hard to reflect the overall situation. The probabilistic load flow computation using probability statistics to solve random factors in the running of the system, and the probability of random close and the actual value. First of all, this paper introduces the calculation model for probabilistic load flow, probability model and the linear communication model includes probabilistic model, the load of the generator. The load power is normal distribution, the output of generator is subject to two probability distribution. Then, introduces the basic concepts of stochastic trend, some calculation method, stochastic trends such as: Monte Carlo stochastic power flow algorithm, probabilistic load flow algorithm for power system nonlinear retention, semi-invariant method power flow calculation. Finally, this paper use half invariant probabilistic load flow algorithm steps, combined with the Gram-Charlier series expansion, distributed random variables, the probability density function of node voltage. In this paper, using MATLAB language programming algorithm, calculated using the IEEE14 node system is stochastic trend, and the example is analyzed. The results show that, this algorithm is feasible. Keywords: power system; probabilistic power flow; cumulant; Gram-Char