基于上下行差流比原理的故障方向识别及广域保护方案

Fault Direction Identification Based on Principle of Differential Current Ratio of Up and Down Track and Wide Area Protection Scheme

全并联AT供电方式下,智能牵引变电所的广域保护在牵引网故障时仅切除故障侧,非故障侧牵引网不断电。本文通过分析全并联AT供电方式下故障时变电所、AT所和分区所电流特征,提出了基于上下行差流比原理的广域保护故障方向识别判据,在发生PT断线时可缩小广域保护无法识别故障方向的范围,提高了广域保护的选择性。

Under all parallel AT power supply mode,the wide area protection for the intelligent traction substation only cuts off the line at the fault side,however,the power of traction network at side of non-fault line is not cut off.The paper,on the basis of the analyzing the current characteristics of substation,AT post and sectioning post under all parallel AT power supply mode,puts forward the criteria for fault direction identification of wide area protection based on the principle of different current ratio of up and down track,it is able to narrow the scope where the fault direction is impossible to be identified by the wide area protection when breakage of PT line is occurred.And it has improved the selectivity of wide area protection.