中低压配电网中接地变压器的保护整定

摘要

With the development of big and medium sized cities power grids, the numbers of power grids feeder terminal continuously grow and the distributed capacitances of medium and low voltage distribution network increase. When grounded fault takes place in power grids, electric arc overvoltage caused by distributed capacitances leads electric arc can not extinguish reliably. Considering economy and security, medium and low voltage distribution network is grounded through small resistance or arc suppression coil which is accessed by grounded transformer and introduces neutral point. In this paper, the protection configuration of grounded transformer is mainly investigated and the protection setting principle of grounded transformer is discussed in detail.%　　随着现在大中型城市电网的发展，电网馈线数目不断的增多，中低压配电网中的分布电容同样也会增大。当电网发生接地短路故障时，由分布电容引起的电弧过电压会导致接地电弧不能可靠熄灭。考虑到经济性和安全性，中低压配电网中通过接入接地变压器来引入中性点，经小电阻或者消弧线圈接地。本文则主要探讨了接地变压器的保护配置，对接地变压器的保护整定原则进行了详细的论述。