基于注入法的小电流接地系统故障定位新方法

介绍了基于“S注入法”的小电流接地系统单相接地故障选线定位保护。当故障停电后，该保护就存在绝缘恢复和定位困难的问题。为此提出了一种定位新方法。该方法通过向停电后的接地线路故障相外加恒定直流高压，再注入交流信号，并根据所注交流信号的消失点准确地判定故障位置。基于新方法的故障定位装置运行很成功。

INJECTING CURRENT BASED METHOD FOR FAULT LOCATION IN NEUTRAL ISOLATED POWER SYSTEM

The protection for earth fault line selection and fault point location by S injecting current in neutral isolated power system is presented. After the earth line is selected out and tripped, the insulation at earth point may be recovered, and the fault location can be difficult. This paper proposes the following methods. Firstly, suitable high DC voltage to the faulted phase is added to form the earth fault again. Then AC current is injected to the faulted phase and exactly a detector available for detecting the injected AC signal determines the fault point. The device based on this principle has been operated successfully.