某主变压器保护多次动作跳闸事故分析

Analysis on Tripping Accidents of Repeated Protection Actions of A Main Transformer

针对重瓦斯保护动作引起主变压器跳闸事故频发,对某35 kV变电站主变压器压器几年来多次跳闸事故的经过进行分析,发现主变压器区外故障产生的穿越性电流可能是造成跳闸的重要原因。通过搭建试验平台对变压器主保护装置进行了大量的电气量保护试验及非电量保护试验,找到了主变压器重瓦斯保护动作跳闸却没有动作报文的原因,并提出将重瓦斯保护的整定值设定为标准范围内的最高上限值来防止主变压器压器区外故障产生的穿越性电流引起重瓦斯保护误动作。

Aiming at the repeated tripping accidents caused by buchholz relay protection actions,the history of repeatedly tripping accidents of the main transformer in a 35 kV substation over the past few years is analyzed,and it is found out that the through current generated by the fault outside the main transformer area may be the important cause of main transformer tripping.A large number of electrical power protection tests and non-electrical power protection tests are carried out on the main protection device of transformer by setting up a test platform.The reasons why the heavy gas protection action of main transformer tripped but there is no action message are found out,and it is proposed that the setting value of heavy gas protection is set as the highest upper limit within the standard range to prevent the through current generated by the fault outside the main transformer area from causing the malfunction of heavy gas protection.