基于环网方向保护协调配合的最小断点集选取方法

Selection of minimum break point set based on coordination of directional protections in loop grid

为实现环网方向保护整定配合起始点的合理选择,给出一种基于保护协调配合性能的最小断点集选取方法。该方法基于继电保护整定配合的阶梯原则,定义了评价环网各级阶段式方向保护整体协调配合性能的测度指标,通过测度指标定量评价最小断点集问题各组可行解的优劣性,进而实现最小断点集问题多组可行解的合理选取;同时给出了基于图论中最长基本路径概念的测度指标计算方法。算例仿真表明,所提方法能够避免最小断点集选取不当引起的保护配合级数过多和动作时限过长问题。

To obtain the reasonable starting points for setting directional protections in loop grid, the method for selecting minimum break point set is studied based on the coordination performance of protections. According to the step principle for setting protection relay, the measurement index is defined to evaluate the coordination performance of directional protections of transmission lines in loop grid, and the effectiveness of each feasible solution of minimum break point set problem can be described by its measurement index value, and the feasible solution with the best measurement index can be further selected as the minimum break point set. Based on the concept of the longest path in graph theory, the method for calculating measurement index is also given. Simulation results show that the proposed method can avoid the inappropriate coordination of protections caused by the unreasonable selection of minimum break point set.