摘要
变压器平衡绕组会因外部干扰源破坏壳体外部的绝缘性能,经避雷器接地的元件故障也会导致变压器短路跳闸。平衡绕组的电流不接入差动保护,没有直观的采样监视保护,排查此类故障具有较大难度。介绍一起平衡绕组引起的故障案例,分析保护动作波形,结合现场情况得出结论:平衡绕组引出桩头未做绝缘处理,在雷雨天气形成过电压闪络,且避雷器用脱离器安装错误未能有效脱离,形成持续性故障。针对案例暴露的问题提出整改意见。
External interference sources can cause deterioration of external insulation of transformer balance windings,and faults of parts grounding through arrester can also lead to short circuit trip of transformers.The current of balance windings is neither connected to differential protection nor monitored by intuitive sampling,so it is difficult to troubleshoot such faults.This paper reports a transformer trip case caused by balance winding and analyzes the activation waveform of differential protection.It can be concluded based on on-site inspection that the improper insulation maintenance of the winding led to overvoltage flashover of the main transformer in thunderstorm weather,and the lightning arrester did not effectively separate due to the incorrect installation of the disconnector,both of which synergistically induced a continuous fault.In view of the problems exposed in the case,some suggestions are put forward.
作者
李慧勇
张伟
LI Huiyong;ZHANG Wei(Inner Mongolia Power(Group)Co.,Ltd.,Ulanqab Power Supply Branch,Ulanqab 012000,China)
出处
《电工技术》
2023年第21期197-198,201,共3页
Electric Engineering
关键词
平衡绕组
避雷器
差动保护
绝缘化
脱离器
balance winding
arrester
differential protection
insulation
disconnector
