一起配电变压器0.4kV侧短路故障的分析

Analysis of Short-circuit Faultonthe 0.4kV Side of a Distribution Transformer

针对某35kV变电所发生的一起短路故障中继电保护未正确动作,0.4kV开关柜烧蚀的情况,通过调取故障录波,采用对称分量法结合一次设备检查对故障过程、保护动作进行分析,提出增加0.4kV开关柜内裸铜排的绝缘防护、间距及缩短保护动作时间、保证配电变压器两侧保护逐级配合的优化建议。

In an incident of short-circuit fault occurring at a 35 kV substation,the relay protection does not act normally and the 0.4 kV switch cabinet is burnt out.By calling the fault recording and adopting the symmetrical component method with one-time equipment inspection,the fault process and protection action are analyzed.On this basis,optimization suggestions are proposed,including enhancing the insulation protection,increasing the spacing,and shortening the duration of the protective action of the bare bar copper in the O.4 kv switch cabinet,so as to ensure step-by-step coordination of the protection on both sides of the distribution transformer.