带并联电抗器的双回输电线路故障测距新方法

A New Fault Location Method of Double-Circuit Transmission Lines with Parallel Reactors

为解决带并联电抗器输电线路两侧电流变化和线路参数不固定产生的故障测距误差问题,提出了一种双回输电线路故障测距新方法。采用集中参数线路模型分析正序、负序、零序故障网络,推导出与线路单位长度阻抗、导纳以及并联电抗器电抗值均无关的故障距离表达式。由线路分相电流差动保护装置纵向通道和横向通道获取四侧同步的模拟量数据,通过调整保护装置的插件功能模块研制出故障测距装置。装置试验结果表明,新方法的测距精度高于装置原有的方法,能解决线路两侧带并联电抗器和线路参数变化引起的测距误差问题,且经过渡电阻故障时仍具有较高的测距精度。

In order to deal with fault location caused by current changes occurring to both sides of transmission lines with parallel reactors and unfixed line parameters,a new fault location method of double-circuit transmission lines is put forward.The paper adopts the lump parameter circuit model to analyze positive sequence,negative sequence and zero sequence fault networks,and generates the fault location expression which is irrelevant to line impedance and admittance per unit and the reactance value of parallel reactors.Then,after achieving four-side synchronized analog data from longitudinal and horizontal channels of the phase segregated current differential protection device,the authors invent the fault location device through adjusting the plug-in function module of this protection device.Test results show that this new method of fault location is more accurate than the old one.It not only can solve the problem of location error caused by changes of parallel reactors and line parameters,but also can have higher ranging accuracy when passing transition resistance faults.