配电网中，大部分馈线都会被安装有电流互感器，但电压互感器却不会大范围配置，因此基于功率方向及电压电流相位差的判据便无法使用。由此可见，开发基于电流信息的保护方案适用范围更广。
In distribution network, most feeders will be equipped with current transformers, but voltage transformers will not be widely deployed, so the criterion based on power direction and voltage-current phase difference can not be used. It can be seen that the protection scheme based on current information has a wider scope of application.
目前配电网单相接地故障选线主要是对各馈线的零序电流进行分析比较，提取零序电流的暂态和稳态特征，例如比幅法、比相法、能量法等。
At present, single-phase grounding fault line selection in distribution network is mainly to analyze and compare the zero-sequence current of feeders, extract the transient and steady-state characteristics of zero-sequence current, such as amplitude comparison method, phase comparison method, energy method, etc