500kV主变B相瓦斯保护跳闸事件分析

Analysis on the Trip Fault Cause by B Phase Gas Generation Protection for 500 kV Main Transformer

在500 kV主变充电过程中,由于瓦斯继电器接点瞬时闭合导致5031开关跳闸。瓦斯保护是主变油箱内绕组短路故障及异常的主保护,安全可靠的运行是其必要条件。文中通过现场调查分析,逐一排除导致5031开关跳闸的可能性,并从主变充电时较大的励磁涌流使线圈收缩和舒展产生油流涌动,分析瓦斯继电器的动作机构得出重瓦斯接点闭合的3个条件以及在油流涌动时带动下浮球摆动是重瓦斯接点闭合的最大可能性入手,解释这次5031开关跳闸事件的原因。

The 5031 switch will trip, which is caused by the gas generation relay contact point transient on in the process of charging of 500 kV main transformer. The gas protection is the main protection of the winding short-circuits faults and abnormal in transformer oil tank, which the safe and reliable operation is the necessary condition for. This paper gradually rules out the possibility which causes the 5031. switch trip by field survey and analysis. The high inrush current makes winding expanding and contracting when the main transformer is charging, which causes the oil wave. Three conditions for the heavy gas contact closure is concluded from the analysis of the action construct of gas relay. The reason for this fault is explained form the most probability of the heavy gas contact closure is the downward floating ball swing when the oil is waving.