基于改进聚类算法的关键输电断面搜索方法

为了有效避免切除故障或过载线路后连锁跳闸事故的发生，提出一种基于改进模糊C均值聚类算法的关键输电断面搜索方法。该方法首先采用改进粒子群算法更新聚类中心，解决聚类算法对初始聚类中心敏感的问题，然后基于改进的聚类算法得到初始输电断面；其次运用Floyd算法搜索含断开线路的最短回路和次短回路，补充漏选的线路到初始输电断面内，构成候选输电断面；最后利用提出的复合因子判据筛选候选输电断面，进而确定关键输电断面。以IEEE 14节点和IEEE 118节点标准系统为例，所提方法可精准搜索得到系统内受切除线路影响较大且可能存在连锁跳闸风险的线路，即关键输电断面。结果表明采用该方法得到的关键输电断面更具有实用性和工程指导价值。

Key Transmission Section Search Strategy Based on Improved Clustering Algorithm

In order to effectively avoid the occurrence of cascading failure due to the loss of faulted or overloaded lines, a key transmission section search method based on an improved fuzzy C-means clustering algorithm is proposed. Firstly, an improved particle swarm optimization algorithm is employed to update the clustering center, so that the problem that the clustering algorithm is sensitive to the initial clustering center can be solved. Then the initial transmission section is obtained based on the improved clustering algorithm. The Floyd algorithm is used to search the shortest circuit and sub-shortest circuit with the disconnected lines, and the missing lines are added to the initial transmission sections to form the candidate transmission sections. Finally, the composite factor criterion is proposed to determine the key transmission sections. Case studies are made on the IEEE 14-bus and IEEE 118-bus standard systems, and it is proved that the proposed method can accurately search out the lines in the system that are significantly affected by the cut-off lines and may have the risk of cascading tripping, i.e. the key transmission sections. The results show that the key transmission sections obtained by this method are more practical and valuable in engineering.