输电线路分相电流差动保护判据的研究

通过分析国内外现有电流差动保护判据的优缺点,提出了变向量窗配合高低门槛反时限出口的故障分量电流差动保护判据与全电流差动保护、故障分量电流差动保护、零序和负序电流差动保护判据分时段相互配合的自适应分相电流差动保护的综合判据,并对影响保护判据性能的电容电流、TA饱和、TA断线、弱馈等问题给出了解决方案。

Research on the criterion of single-phase current differential protection for power transmission line

With the power grid becoming more and more complex and multiple day by day, the single-phased current differential protection has become the main protection for power transmission line. However, there are both advantages and disadvantages in digital single-phase current differential protection devices existing criterions. Through analyzing the advantages and disadvantages of the domestic and alien current differential protection criterions, an adaptive single-phased current differential protection criterion is put forward. The new criterion is mainly about the time-period sharing cooperative fault components combining variable vector windows fitting in high-low threshold inverse time leg tipping in 50 ms' fault time with the whole current differential protection, the fault component protection, zero-sequence and negative-sequence current protection after 50ms' fault time. The feasible solutions of capacitive current, TA saturation, TA wire break and weak feed system are presented.