限制短路电流的线路开断全方案搜索方法

Method of Searching All Feasible Breaking-line Schemes for Limiting Short-circuit Current

开断部分输电线路是限制电网短路电流水平的常用措施,由于单一的开断方案可能不能满足电网日益灵活多变的运行要求,为此提出了满足短路电流限制要求的线路开断全方案搜索方法.首先证明了节点短路电流与线路投切存在着单调关系;然后将开断方案表示为所开断线路的集合,进一步推导了开断方案的超标节点集与开断方案的子集方案(或超集方案)存在单调关系;利用这一关系得到了快速筛选开断方案的策略,避免了穷举所有线路开断方案.通过对IEEE 9节点系统和河北南部电网某分区220 kV层网络的算例分析,验证了基于上述原理的搜索方法的有效性.

Breaking part of the transmission lines is a common measure to limit the short-circuit current(SCC)in a pow⁃er system.Since one single breaking-line scheme may hardly meet the increasingly flexible requirements of grid opera⁃tion,a method is proposed in this paper for searching all feasible breaking-line schemes that meet the SCC limitation re⁃quirements.First,a monotonic relationship between the nodal SCC and the switching line is proved.Then,the break⁃ing-line scheme is expressed as a set of its breaking lines,and the monotonic relationship between the corresponding SCC-exceeded-node set and the scheme’s subsets(or supersets)is further deduced.On this basis,a strategy for rapid⁃ly searching the feasible breaking-line schemes is formed,which can avoid validating each single scheme.The effective⁃ness of the proposed method based on the above principle is verified by two case studies,in which an IEEE 9-bus sys⁃tem and a 220 kV network in one subregion of Hebei Southern Power Grid are analyzed,respectively.