摘要
介绍了目前常见的几种基于故障分量的T型线路电流差动保护判据,并对各种判据的动作特性及制动特性进行了对比分析。在此基础上,研究分析了影响电流差动保护性能的制动量及制动系数的选取问题,通过对原有判据制动系数的改进,提出了一种改进的T型线路电流差动保护判据,并对改进前后判据的工作情况进行了大量的仿真试验。仿真结果表明,该判据具有良好的分相动作能力,并可根据外部故障和内部故障,自动调节制动系数,使得该判据在灵敏度、可靠性以及允许误差范围等方面均具有更好的性能,在发生电流互感器饱和、内部故障有穿越性电流流出等情况下也能正确动作。
Some criteria of differential current protection for T-type transmission lines are. introduced, and their acting and restraining characteristics are compared. The selection of restraint components and restraint coefficients which influence the performance of differential protections are studied and a new criterion improved in its original restraint coefficient is proposed for the differential current protection of T- type transmission lines. The operating conditions before and after its improvement are compared by simulative tests. Results show that,the improved criterion has good ability of phase -separation action and adjusts its restraint coefficient automatically according to internal or external fault, with better sensitivity,reliability and error tolerance. In cases of CT saturation or through current during interior faults,it acts properly.
出处
《电力自动化设备》
EI
CSCD
北大核心
2008年第10期58-63,共6页
Electric Power Automation Equipment
关键词
T型线路
差动保护
灵敏度
可靠性
电磁暂态仿真程序
T-type transmission lines
differential protection
sensitivity
reliability
alternative transient program
