断路器拒动引起110kV变电站失压的事故原因分析

对一起由于110 kV断路器拒动引起2座110 kV变电站失压的事故原因进行了分析。在现场检查、线路巡查以及雷电定位相关数据分析的基础上,结合保护动作报告、录波数据、事件顺序记录等,对事故中线路跳闸、断路器拒动和保护动作情况进行了分析,认为单环网的薄弱电网结构是引发事故的根本原因,而小水电站未安装过电压及高低周保护装置、易遭受雷击的杆塔未采取防雷措施等是导致事故的间接原因。提出优化电网结构,改造变电站110 kV母线接线方式,在易受雷击杆塔上安装线路避雷器,重要线路断路器配置双跳闸线圈等整改措施。

Cause Analysis of Voltage Loss Accident in 110 kV Substation Triggered by Failure to Operation of Breakers

The paper analyzes causes for a voltage loss accident in two 110 kV substations triggered by unwanted operation of 110 kV breakers. On the basis of analyzing data from filed test, line inspection and lightning location, the paper, in combination with report of protection action, recorded data and recorded event sequence, analyzes line trip, failure to operation of breakers and protection action. It is believed that the fundamental reason of the accident rests with weak grid structure of single loop network, while the indirect reason is that there is no overvoltage or high and low cycle protective device installed in small hydraulic power plants and no lightning protection measures taken on poles and towers frequently suffering from lightning strike. The paper suggests some measures such as grid structure optimization, transformation of wiring mode of 110 kV bus, installation of arresters on frequently-stricken poles and towers as well as configuration of double-trip coil for key line breakers.