On the basis of Xiangfan power grid, the formation background and working principle of district grid standby power auto-switching in were introduced.

以襄樊电网为工程实际基础，介绍了区域电网网络备用电源自动投入系统产生背景、工作原理。

To save on fuel consumption, the city began laying heating pipes to form an underground heating grid - so-called district heating.

为了减少燃料消耗，该市开始铺设供热管道，建起了一个地下供热网，即区域供热体系。

According to features and requirements of modern district power grid, the development of software for graphic integrated fault analysis and relay protection test is researched.

从现代地区电网的特点和需求出发，研究了图形化综合故障分析与继电保护测试软件的开发。