【作者】 杨青； 郑涛； 肖仕武； 黄少锋； 刘万顺；

【Author】 YANG Qing ZHENG Tao XIAO Shiwu HUANG Shaofeng LIU Wanshun(Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control under Ministry of Education (North China Electric Power University),Changping District,Beijing 102206,China)

【机构】 电力系统保护与动态安全监控教育部重点实验室(华北电力大学)；

【摘要】 为有效地防止变压器在区外故障时因电流互感器(TA)饱和引起的差动保护误动,本文提出了一种简单的闭锁方法。该方法是选择变压器两侧电流突变量的最大有效值与差电流的突变量有效值进行比较,使得即使在TA快速深度饱和(2ms)的情况下,仍能快速可靠的闭锁差动保护,防止误动;并且,当变压器绕组内部发生轻微匝间短路故障时,也能灵敏的开放保护。新方法原理简单,计算快速,性能可靠。经大量仿真实验验证了该原理的正确有效性。更多还原

【Abstract】 To avoid the mal-operation of transformer differential protection when out-zone fault occurs under current transformer saturation,a simple method of latch-up protection is put forward in this paper.This method carries on the comparison between the maximal virtual value of current mutational volumes which is chosen in the two sides of transformer,and the virtual value of differential current mutational volume.Although in the case of TA’s quick and serious saturation,differential protection still latches rapidly and reliably,avoiding mal-operation.In addition,this principle is also suitable for the slight turn-to-turn inner-fault for the transformer winding.The new method needs a little calculation,a short data windows and has reliable performance.Lots of simulation results validate its precision and availability.更多还原