考虑大规模风电对电网频率影响的快速随机潮流算法

Fast probabilistic power flow algorithm considering the impact on power frequency of large scale wind power injection

随机潮流模型可以考虑电力系统中的不确定性因素,较为全面地反映系统运行状态。风电出力具有波动性和间歇性,大规模风电接入对系统频率的影响不容忽略,考虑风电多场景模型可适应解析法线性化随机潮流模型。基于快速解耦潮流法构建随机潮流模型,考虑电力系统功频静态特性,建立风电出力多场景模型。通过应用全概率模型计算方法,采用半不变量和Gram-Charlier级数展开方法,能快速计算得到节点电压、支路功率和系统频率的概率密度函数(probability distribution function,PDF)和累计概率分布函数(cumulative distribution function,CDF)等统计信息。IEEE RTS-24节点实验系统计算结果表明:所提方法可快速、准确地计算得到待求变量的概率分布,具有实际应用价值。

Probabilistic power flow can take account of the uncertainties in power system, which can reflect the operating condition of a power system comprehensively. Large scale wind power injection has great impact on power frequency due to its fluctuation and intermittent, and the multi-scenario model of wind power adapts the linearized probabilistic power flow algorithm. Based on the fast decoupled power flow, a fast probabilistic power flow model was established. Considering static power-frequency characteristics, the wind power multi-scenario model was proposed. Combining the complete probability method with cumulant and Gram-Charlier expansion, the node voltage, the branch power, the probabilistic density function （PDF） and cumulative distribution function （CDF） of system frequency can be calculated rapidly. The simulation results of the IEEE RTS-24 system verified the rapidity and validity of the algorithm.