计及离散分布输入变量的电力系统概率潮流计算方法

Probabilistic Power Flow Calculation Method of Power System Considering Input Variables With Discrete Distribution

发电机组的随机故障停运对电力系统潮流计算产生影响,应用传统半不变量法计算概率潮流(probabilistic power flow,PPF)将产生较大误差。提出一种考虑离散分布输入变量的半不变量法PPF计算方法。针对服从离散分布的发电机注入功率采用多点线性化方法,减小潮流方程线性化误差。同时,引入阈值分析策略,提高计算效率。最后,综合运用A型Gram-Charlier级数和C型Gram-Charlier级数拟合状态变量的概率分布。对IEEE-RTS 24节点系统进行仿真,验证了算法的准确性和实用性。结果表明:所提PPF计算方法具有较高的精度,并保持一定的计算效率。

Random failure outage of generators has impact on power flow calculation. Thus, when conventional cumulant method based probabilistic power flow（PPF） calculation is performed, it will lead to relatively large errors. Considering input variables with discrete distribution, a cumulant based PPF method was proposed. In order to reduce power flow model linearization error, multipoint linearization method was used to deal with power injection of generator with discrete distribution. Meanwhile, threshold analysis was put forward to improve computational efficiency. Finally, combination of A-Type and C-Type Gram-Charlier series was used to estimate probability distributions of state variables. Accuracy and efficiency of the algorithm is verified with stimulation of IEEE RTS 24-bus system. The results indicate that the proposed method can solve PPF problem accurately and quickly.