厂站低压直流系统接地查找

Earthing search for low-voltage DC system in plant station

低压直流系统为厂站的继电保护装置、跳合闸线圈提供电源,直流接地降低了电网的可靠性,可能会给电网带来灾难性的后果,所以必须快速地查找并消除接地点。目前最有效彻底的方法就是通过"试拉法"缩小故障范围,然后再借助其它手段找到接地点。通过建立厂站的直流系统信息台帐,把直流回路分布情况直观地体现出来,帮助查找人员准确、快捷地锁定接地点。按照分网法缩小查找范围,把直流系统分成几个不相联系的部分,最终找到故障点。

Low-voltage DC system provides power for protection devices, tripping and closing coils. Otherwise, DC system earthing fault debases the grid reliability, and may even result in disastrous consequences. So the earthing point must be found out and eliminated as quickly as possible. At present, the most effective way is pull test method, it is helpful to eliminate the scope of fault and then use other methods to find the earthing point. Establishing original record of DC system for plant station can embody the distribution of DC circuit intuitively and can help the searcher lock the earthing point accurately and quickly. Net-separate method narrows the scope of searching point, and separates the DC system into several disjunct parts, thus, the earthing point can be found out finally.