一次间隙零序引起主变动作事故分析

The Accident Analysis of Transformer Action from Zero-Sequence

电力变压器是变电站的重要设备,继电保护装设了主保护和后备保护来提高对变压器的保护灵敏性和可靠性,装设有一段两时限间隙零序过流保护和一段零序过压保护,作为变压器中性点经间隙接地运行时的接地故障后备保护,主要是体现外部短路时流过变压器中性点的零序电流来体现的一种后备保护,雷电产生的对某一相的过电压可以产生间隙放电,导致主变保护的间隙零序动作,跳开主变三侧的断路器,以某110kV变电站的设计问题,对雷电天气发生一起间隙零序保护动作故障进行分析,并提出了预防类似情况的一些具体措施,对今后预防类似事故的发生有一定的指导作用。

Power transformer is an important equipment for substation, relay protection installation the main transformer and backup protection to improve the sensitivity and reliability for the protection, equipped with a two time overcurrent protection and overvoltage protection , as the transformer neutral point gap ground running when the backup ground fault protection, mainly external short circuit current through the transformer neutral point of a back-up protection, lightning over-voltage of a phase of the discharge gap can be generated, to the design question of a 1 lOkV substation, in the lightning weather, occurred, clearance gap caused by over-voltage zero-sequence protection action, and proposed to prevent a similar situation a number of specific measures to prevent future similar accidents have some guidance.