基于拓扑分析的电网薄弱断面智能辨识与评估

Intelligent Identification and Evaluation of Weak Section of Power Grid Based on Topology Analysis

新能源大规模并网加剧了大电网运行的随机性和波动性,能够及时辨识电网薄弱断面对大电网安全控制具有重要作用。文章在分析实际电网拓扑特性的基础上,给出了薄弱断面的定义,结合图论搜索算法提出了一种基于拓扑分析的电网薄弱断面智能辨识方法,该方法从搜索全覆盖视角构建了电网薄弱断面搜索算法包,由单层潮流特性出入度搜索、单层约束广度优先搜索、单层约束组合开断模拟搜索、跨层连通子图搜索和多层组合薄弱断面搜索5种分析算法构成,从而实现了对跨区跨电压大规模电网下的薄弱断面智能辨识,并根据国家电网有限公司电网事件等级规则给出了薄弱断面评估定级方案。通过在省级电网实际系统的成功应用表明,所提方法在约4000节点电网拓扑中辨识时间小于1 min,满足在线实时应用。

The large-scale grid connection of new energy intensifies the randomness and volatility of largescale power grid operation.To identify the weak section of power grid in time is important in the security control of large-scale power grid.Based on the analysis of the actual power grid topology characteristics,this paper gives the definition of weak section,and proposes an intelligent identification method of power grid weak section based on topology analysis combined with graph theory search algorithm.This method constructs a power grid weak section search algorithm package from the perspective of search full coverage,which consists of five analysis algorithms including single-layer power flow characteristic access search,single-layer constraint breadth first search,single-layer constraint combined outage simulation search,cross layer connected subgraph search and multi-layer combined weak section search,so as to realize the intelligent identification of weak sections under the large-scale power grid with cross region and cross voltage,and the evaluation and grading scheme of weak sections is given according to the power grid event rating rules of the State Grid Corporation of China.The successful application in provincial power grid shows that the identification time of the proposed method in about 4000 node power grid topology is less than 1 min,which meets the online real-time application.