一起20 kV侧接地小电阻二次回路烧毁事故分析

Burning Fault Analysis of Small Grounding Resistence in Secondary Circuit on 20 kV Side

设备设计缺陷可能会引发事故,分析造成缺陷的原因,以便从源头上消除隐患。对某110/20 kV变电站内某20 kV线路发生接地故障期间,一起主变压器20 kV侧接地小电阻二次回路烧毁的异常事故进行调查分析,根据现场实测的故障录波数据分析,以及对现场相关装置设备检查,研究了相关标准规范,判断故障的直接原因是由于所使用的箱式接地变压器有设计缺陷造成的。在进一步调查分析后,提出了故障处理以及有关运行相关规范内容应完善等建议。

The design defect of equipment can cause faults. The cause of defect should be analyzed to eleminate it from beginning. The burning fault of a small grounding resistence in secondary circuit on 20 kV side of master transformer, during the grounding fault on a 20 kV line in a 110/20 kV substation, is researched and analyzed. According to the recorded fault data analysis, which are measured onsite, and checking on relevant equipments, researching on relevant standards and norms, the direct cause of this fault is the design defect of the box grounding transformer oil. The further research and analysis submits the countermeasures and suggestions on improving the relevant standards and norms etc.