基于分布参数模型的T型输电线路电流差动保护新原理

A New Current Differential Protection for Three-Terminal Transmission Lines Based on Distributed Parameters Model

在目前双端线路电流差动保护新研究成果基础上,提出一种基于分布参数模型的T型输电线路电流差动保护新原理,将原三端线路电流差动保护问题转化为2个原理相似的双端线路电流差动保护问题,并分析了这种转化的正确性。与传统T型线路全电流差动保护相比,新保护判据不受分布电容电流的影响,适用于T型高压输电线路。仿真结果表明了该判据的可行性和正确性。

Due to the fact that the distributed capacitive current in three-terminal transmission lines significantly influences the protection performance, such influence should be taken into account in the protection principle. On the basis of new research findings of current differential protection for two-terminal transmission lines, a new distributed parameter model based principle of current differential protection for three-terminal transmission lines is proposed. Translating original current differential protection for three-terminal transmission line into two current differential protections for two-terminal transmission lines, which are similar in principle, the correctness of such a translation is strictly proved by distributed parameter model. Comparing with traditional post-fault current differential protection for three-terminal transmission lines, new protection criterion is not influenced by distributed capacitive current, so it is suitable to three-terminal high voltage transmission lines. Simulation results show that the proposed criterion is correct and feasible.