小电源并网对110kV变压器中性点保护的影响

Influence of Small Power Connected on Neutral Protection of 110kV Transformer

110kV变电站主变中、低压侧有小电源并网运行,当110kV进线故障时,若主变中性点保护定值整定不合理则会造成在线路重合闸前主变各侧开关已跳闸或无条件重合将小电源强行拉入系统。针对这种问题,文章对主变中性点保护的定值整定和配合进行了改进。

In the transformer of110kV substation,there is a small power supply on the low-voltage bus or middle-voltage bus.When the110kV line fails,if the set value of the neutral point protection is set unreasonably,it will cause the switch at each side of the main transformer to be tripped before the reclosing or Unconditionally coincident pull small power into the large system.In view of this kind of question,the article has carried on the improvement to the definite value setting and cooperation of the transformer neutral point protection.