基于零序电流比值变化的小电流接地选线方法  

A method of single-phase grounded feeder detection in indirectly earthed power system based on judging the change of zero-sequence current ratios

作　　者：徐梅[1] 杨文荣[1] 吴淑梅[2] 王柱[1] 

机构地区：[1]河北工业大学电磁场与电器可靠性省部共建国家重点实验室培育基地,天津300130 [2]河北科技大学电气信息学院,河北石家庄050018

出　　处：《电力系统保护与控制》2009年第14期68-71,92,共5页Power System Protection and Control

摘　　要：在小电流接地电网发生单相接地故障时,由于消弧线圈的补偿,接地残流过小,难以准确选线。分析现有小电流选线原理和方法,总结提出零序电流比值选线法。它根据消弧线圈容量变化前后,零序电流比值变化趋势不同,确定接地故障线路。对该方法进行理论分析,推导出零序电流比值关系式。并利用Matlab工具进行仿真分析,结果符合理论推导。此方法不需要延缓切除阻尼电阻,有足够快的响应速度,算法简单,实现容易,对配电网当前状态和长远发展有良好适应性。When single-phase-to-ground fault occurs in the indirectly power system,with the compensation current of the arc-suppressing coil ,it is difficult to select the fault line.After analyzing the line selection methods at present, the zero-sequence current ratio method is presented.It is based on judging the change of zero-sequence current ratios after the compensation.According to the deduction, the formula is presented.Simulation with Matlab shows that this calculation method has high accuracy.The delay of cutting damping resistance is not needed,and it can select the fault line quickly and accurately.

关 键 词：小电流接地 零序电流比值 单相接地故障 选线 消弧线圈 

分 类 号：TM862[电气工程—高电压与绝缘技术]