220kV贺金线输电线路保护动作分析

Analysis of 220 kV Transmission Line Protection Action of Helanshan-Jinnuo Substation

220 kV贺金线长161.38 km,为长距离输电线路。采用的CSL-101B输电数字式高压线路保护装置运行中保护范围内发生6次故障,其中3次主保护高频保护正确动作,3次主保护高频保护拒动。利用RTDS实时数字模拟系统搭建数模试验模型,对220 kV贺金线CSL-101B高频保护进行数模试验,分析认为金贺线线路分布电容较大,系统投入多组高压和低压并联电抗器,故障时产生较大的谐波分量,而CSL-101B保护装置滤波能力相对较弱,当谐波分量较大时,先投入的高频距离保护判断为反方向,进入功率倒向逻辑,保护延时停信,由于2套保护中的差动保护动作快,因此CSL-101B高频保护延时118 ms,来不及动作,其他保护功能可正确动作,建议对该保护装置进行更换。

The length of 220 kV line Helanshan-Jinnuo is 161.38 km. CSL-101B high voltage line protection device failure occured six times during operation. Using real-time digital simulation system to build D/A test model. Through simulation test, the author found out the cause of the failure, which is that transmission line distributed capacitance is large, lots of high resistances and low resistances have been used. When the failures oecured, the large distributed capacitance generated. While the device filter ability is weak, the large distributed capacitance resulted in the first investment in high frequency distance protection judgement for the reverse direction, which is into power converse logic, protection delay stop signal. The proposal of changing the orotection device is nut forward.