区外故障引起零序方向保护误动的原因分析

摘要

Zero sequence directional power protection is widely used in neutral directly grounded system. In normal conditions, there are two causes of maloperation of zero sequence directional protection, i.e, a fault from the device itself and wrong wiring outside the device. For ensuring correct wiring, a great of active tests on site should be done before the protection is put into operation. In this paper, an unique fault cause is presented here and the analysis and searching result is showed. It is helpful to relay engineers.%在大电流接地系统中广泛采用着零序功率方向保护。而造成零序方向保护误动的原因无非两种，其一是由于装置本身故障引起的；其二则是由于装置外部接线错误造成的。为确保外部接线的正确性，在零序方向保护投入运行时，我们将进行大量的现场带电测试。然而一个小小的疏忽则会酿成大的事故。因本例故障原因较为特殊，现就分析和查找的结果，奉献给大家，以期继电保护的同行在工作中引以为戒。