基于短路容量的含大规模新能源接入的电网状态脆弱性评估方法研究

摘要

In order to accurately analyzetherunning featuresofload nodes with large-scale new energysources accessto thegrid, according to theThevenin equivalent theory,the electric network system including large-scale new energy sourcescan beequivalent to 3 nodes.On the basis of the equivalent system, thestate vulnerability assessment method and index based onshort-circuitcapabilityfor load nodesare built up, which makes the system of state vulnerability assessment more perfect. Based on theresultsof statevulnerabilityindex,the PAM clustering algorithm and Homogeneity-Separation (HS) index are used to find out the nodes which need more attention.In addition,theimprovedIEEE-39 node system is simulated andanalyzed. The result is compared with that of traditional voltage margin index assessment, simulation shows theeffectiveness of this state vulnerability assessment method based onshort-circuitcapability andthe rationality of usingthe PAM clustering algorithm to identify weak nodes, whichhavethe application ofon-line prospect.%为了准确分析大规模新能源接入电网后负荷节点的运行特性，根据戴维南等值理论，将大规模新能源接入后的电网络等值为3节点系统。在该等值系统的基础上建立了基于短路容量的状态脆弱性评估模型及指标，使状态脆弱性评估体系更完善。在计算所得的状态脆弱性指标的基础上，采用 PAM 聚类算法和Homogeneity-Separation(HS)评价指标来自动聚类分级后，辨识出系统的脆弱节点。基于该方法，对改造的IEEE39节点算例进行了仿真分析。通过与传统的电压裕度指标评估结果的比较，仿真结果表明，利用短路容量可以准确评估负荷节点的状态脆弱性；且应用 PAM 聚类算法进行薄弱节点辨识方法的可行性及适用性，具有在线评估的应用前景。