两起220kV变电站主变压器跳闸故障分析

Failure analysis on two cases of main transformer trip in 220 kV substation

针对某220 kV变电站连续发生的两起主变压器跳闸故障,根据故障信息及相关试验结果进行分析,找出导致主变压器跳闸的原因,提出对树脂浇注式电流互感器在投运前开展局部放电检测,在中性点非有效接地系统推广接地转移技术等措施。应用结果表明:改进措施有效防止了因树脂浇注式电流互感器主绝缘击穿导致的主变压器跳闸故障的发生。

Aiming at two cases of main transformer trip fault continuously happened in a 220 kV substation, according to failure informations and relevant test results, finds out the causes of main transformer trip, puts forward the measures such as to develop partial discharge detection before the commission of resin- casting type current transformer, and to generalize the grounding transfer technology in non- effectively neutral grounded system. The application result shows that the improving measure can effectively prevent main transformer trip fault happening due to main insulation breakdown of resin-casting type current transformer.