基于枚举抽样法的城市电网风险评估

Risk Assessment of Urban Power Network Based on Enumerative Sampling Method

介绍了城市电网风险评估的基本概念,提出了城市电网风险评估模型及其指标的计算方法。首先确定元件的停运模型,然后以各负荷点的负荷变化曲线为基础采用枚举抽样法对各系统状态进行抽样计算与分析。通过计算各种运行状态出现概率和累积计算结果,得到城市电网的负荷损失概率、期望缺供电量等风险评估指标。该模型充分考虑了城市电网结构的复杂性、负荷变化的随机性和重要用户的分布等因素,可以从风险水平的高低反映出城市电网运行中的薄弱环节。算例分析验证了本文模型和方法的有效性。

The basic concept of risk assessment for urban power network is presented, and a risk assessemnt model for urban power network and the calculation of its indices are proposed. Firstly, the outage model of components is decided; then based on the load variation curves of load nodes the sampling, calculation and analysis of various system states are performed by enumerative sampling method. By means of computing the occurrence probabilities of different operation modes and accumulating computation results, the risk assessement indices such as lost of load probability （LOLP） of urban power network, expected energy not supply （EENS） and so on are achieved. In the proposed model, factors such as complexity of urban power network structure, randomness of load variation and distribution of important consumers are fully considered, thus the weak links in urban power network operation ban be reflected by the values of risk levels. Case study results verifiy the effectiveness of the proposed model and method.