某电厂500kV开关站线路分相电流差动保护简析

Analysis on Phase Current Differential Protection of 500KV Swit ch Station Line in a Power Plant

线路差动保护从原理上是理想的一种保护方式,光纤分相电流差动保护借助于线路光纤通道,通过对电流的测量,实时地向对侧传递采样数据,同时接收对侧的采样数据,各侧保护利用本地和对侧电流数据按相进行差动电流计算。根据电流差动保护的制动特性方程进行判别,判为区内故障时动作跳闸,判为区外故障时保护不动作。

The line differential protection is an ideal protection mode in principle,with the help of optical fiber channel,the optical fiber split phase current differential protection transmits the sampling data to the opposite side in real time by measuring the current,and receives the sampling data from the opposite side at the same time.Each side protection calculates the differential current according to the phase by using the local and opposite side current data.According to the braking characteristic equation of the current dif ferential protection,it is judged that the protection will trip when the fault is in the area,and the protection will not operate when the fault is out of the area.