在我国，10-35kV配网系统大部分属于小电流接地系统，即中性点不接地系统或中性点经消弧线圈接地系统。小电流接地系统最大的优点是当发生单相接地故障时，单相接地故障的故障电流较小，不会破坏配网系统线电压的对称性，配网系统可以最多连续运行两小时。但是，当系统发生单相接地时，如何快速准确的判断出故障线路，并将故障线路从系统中切除一直是一个难题。常规的人为“推拉”试验虽然可以找出故障线路，但是这种方法存在着很多缺点。所以，为减小小电流接地系统发生故障的危害，应市场的广泛需求，小电流接地系统故障选线装置发展很快。小电流接地系统中安装灵敏、可靠、经济的选线装置也是十分必要的。 110kV招商变电站建于2000年，并于同年10月正式投运，该站按无人值班站设计。该站有两个电压等级，110kV﹑10kV。现投运十三条馈线，且全部为架空出线。由于线路路径复杂，10kV系统发生单相接地故障较多，目前人为“推拉”试验的选线方法存在许多缺点，公司决定在110k招商变电站安装一台小电流接地系统故障选线装置。 本文重点对小电流选线装置的选线原理进行了对比，确定选用一套基于参数识别原理的选线装置——XRA-600小电流接地选线装置。对XRA-600型小接地电流系统接地选线装置的选线原理、主要特征、选线原理、软件实现进行了介绍，并利用现场录波数据进行了验证。 110kV招商变电站自12年7月14日安装了一台西安西瑞保护控制设备有限责任公司XRA-600小电流接地选线装置以来，随即将XRA-600小电流接地选线装置投入运行。截止目前，装置运行情况正常，能够在发生故障后正常的动作及发送报警信息。缩短了选线时间，减少了倒闸操作量，避免了对正常用户的停电，避免了对重要用户的单电源运行风险，提高了供电可靠性，避免了事故的发生，延长了变电设备检修周期，减少了变电设备检修费用。

In China, most 10-35kV distribution systems are Small current grounding system ,which means ungrounded or grounded via arc-suppression coil. The biggest advantages of the small current grounding system is when the single-phase ground fault occurs, the fault current is small, it won’t destroy the symmetry of the distribution network system line voltage . distribution network system can be up to two hours of continuous operation. However, when the system of single phase grounding, how to quickly and accurately find out the fault line, and how to cut out the fault line from the system resection. It has always been a hard call. Artificial"push-pull" test can identify the fault line, but this approach has many drawbacks. So ,in order to reduce the hazards of small current grounding system failure, nowdays the Fault line selection device develops very fast. installing a sensitive, reliable and economical line selection device to the Small current grounding system is also very necessary.Zhaoshang 110kV substation was built in 2000 and officially put into operation in October of the same year, the station is on unmanned station design. The station has two voltage levels, 110kV, 10kV. Now 13 lines put into operation, and all are overhead outlet. The complex line path occurs 10kV system single-phase ground faults. The company decided to install a small current grounding system fault line selection device in the 110k investment substation.we compared many small current line device, and decide to use- XRA-600 small current grounding line selection device based on the principle of parameter identification. This article will introduce XRA-600 small ground current grounding line selection device, including select line principle, the main features of the line selection theory, software implementation and will Record live wave data to verify. Zhaoshang 110kV substation installed XRA-600 small current grounding line selection device, on July 14,2012, which produced by Xi'an Desiree protection control equipment limited liability company Since then, the device is running normally, the normal action and warning messages are sent after a failure. Shorten the line selection time, reducing the amount of switching operation, to avoid the blackout of the normal user, and to avoid the risk of important users of single-supply operation, to improve the reliability of power supply to avoid accidents, extending the substation equipment maintenance cycle, reducing the substation equipment maintenance costs.