小电流接地系统具有供电可靠性高，故障时对设备冲击小的特点，在中国配电网中应用广泛。但配电网单相接地故障十分频繁，影响系统的安全运行，导致设备损坏，同时直接影响供电可靠性。
The low current grounding system has the characteristics of high reliability of power supply and low impact on equipment when fault occurs. It is widely used in China's distribution network. However, the single-phase grounding fault in distribution network is very frequent, which affects the safe operation of the system, leads to equipment damage, and directly affects the reliability of power supply.
而小电流接地系统又以中性点不接地或经消弧线圈 接地为主，其接地电流十分微弱（≤10A），传统的小电流接地检测装置难以检测，古被称为“世界难题” ！
The neutral grounding system is not grounded or grounded by arc suppression coil. Its grounding current is very weak (< 10A). The traditional detection device for small current grounding is difficult to detect. It was called "the world's problem" in ancient times