牵引供电系统异相短路保护的新方案  

A New Approach of Relay Protection for Phase-to-phase Faults in Traction Distribution Networks

作　　者：张艳霞[1] 周莹莹[1] 陈鸿雁[1] 

机构地区：[1]天津大学电力系统仿真控制教育部重点实验室,天津市300072

出　　处：《电力系统自动化》2008年第7期53-56,共4页Automation of Electric Power Systems

摘　　要：电力机车不降弓通过牵引变电站时容易引发异相高阻电弧短路,此时常规保护将出现拒动。文中建立了高阻电弧故障仿真模型和牵引供电系统接触网模型,并对异相短路的特征进行了分析。根据异相短路时故障相间电压中3次谐波含量高的特点,提出了利用检测故障相间电压大小和3次谐波含量的保护方案。该方案不受变压器空载投入和受电弓接入瞬间的暂态电压影响,能正确区分异相短路和常规短路,且具有原理简单、易于实现的特点。When trains pass through the traction substation without putting down their pantograph, an arc fault between the different phases can be easily caused. In this situation, common relay protection will refuse to trip. The models of high arcresistant fault and traction distribution networks are built and the characteristics of fault signals are analyzed. According to the characteristic of large amount of the third harmonic existed in the voltages of between phases, a new approach of relay protection for phase-to-phase faults is presented, which works by detecting the voltage value between faulted phases and the percentage of the third harmonic. This approach is not affected by the transient voltages of transformer＇s unload switching-on or the train pantograph switching-on, and can distinguish the fault between different phases from common faults correctly. It also possesses the advantages of simple and easily achieved.

关 键 词：牵引供电系统 异相短路 电弧模型 保护方案 

分 类 号：TM922.3[电气工程—电力电子与电力传动]