反时限电流保护整定计算相关问题研究

分析比较了不同平坦度特性的反时限电流保护特点并提出其适用范围.通过建立反时限特性方程,对反时限电流保护之间的配合进行了理论分析,依据保护范围内时间差关系,得出满足选择性的2个结论:在被配合线路出口故障时上下级保护动作时间有级差;上级保护的电流倍数小于下级被配合保护的电流倍数.该结论适合于任意开环、闭环网络.在该结论基础上对反时限保护提出了切实可行的整定方案.最后,对定时限与反时限电流保护配合以及反时限与定时限电流保护 选择性配合进行了分析.

Setting coordination of inverse-time over-current relays

Inverse-time over -current relays with different characteristic curves are compared and their applicable occasions are proposed.The inverse -time characteristic equation is built,with which the coordination between inverse -time over -current relays are theoretically discussed.According to their time differences within protective range,two conclusions are presented to satisfy the selectivity:higher level relay should function later than lower level relay for line outlet fault;the current multiples of higher level relay should be smaller than that of lower level relay,which is suitable for both closed -loop and open -loop networks.Practical setting coordination schemes are put forward for inverse -time relays.The coordination between definite -time over -current relay and inverse -time over -current relay is discussed.