500kV变压器中性点备用小电抗器运行方案探讨

对我国现行500kV变压器中性点经小电抗器接地运行方案进行了介绍。由于不允许中性点具有不同接地方式的变压器并联运行,小电抗器维修将迫使该变压器停运,带来不必要的经济损失。也使零序网发生不必要的改变。这是它的不足。为使小电抗器维修时变压器停运时间尽可能短,提出了公共备用小电抗器运行方案,并论述了运行原则。从调度、运行、继电保护角度看,问题被简化。从实用角度,提出了电动隔离开关的一种自动切换方法,结合备用小电抗器投入和退出原则进行了较详细的说明。

An operating scheme discussion on the 500 kV transformer neutral point spsare small reactor

This paper introduces the operating scheme on the 500 kV transformer neutral point grounding via small reactor currently used in our country. Since it is not allowed that the transformer operates in parallel with the neutral point that has different grounding methods, the maintenance of the small reactor will force the transformer stop operating, which will bring unnecessary expenses as well as unnecessary changes of the zero sequence networks. This is the disadvantage of this current method. In order to make the transformer stop working as short as possible during the maintenance of the small reactor, this paper presents the operating scheme of the public spare small reactor and states its working principle. The problem is simplified from the perspective of the maneuver, operation and relay protection. Also from the practical perspective, this paper presents an automatic switching method of electric power isolating switch, and explains in detail of the in-and-out principle with the combination of the spare small reactor.