10 kV配电网含分支混合线路故障行波定位研究

Research on Fault Traveling Wave Location of 10 kV Distribution Hybrid Line with Branches

考虑配电网实际结构,建立配电网常见的架空线—电缆混合线路模型,设置分支点和分支线路,模拟分界开关和环网柜及其出线情况,提出分支域的概念。基于此提出一套故障定位方法,首先比较分支域外和域内故障时各分支线路末端与支路分支点初始行波到达时差的不同,以确定故障是否发生于分支线路;其次将实际故障时混合主干线路初始行波到达始末端的时差值与分支点和线缆连接点故障时相比较,并结合分支线路故障判据以确定主干线路的故障区段;最后提出简单的单双端行波组合测距方法,确定具体故障位置。PSCAD仿真结果证明,该套定位方法能较为准确地选出故障线段,并确定故障位置。

Considering the actual structure of distribution network,the common overhead line-cable hybrid line model of distribution network is established,branch points and branch lines are set,the boundary switches and ring network cabinet and their outlet situation are simulated,and the concept of branch domain is put forward.Based on this,a set of fault location method is proposed.Firstly,compare the difference of travel wave arrival times between the end of the branch line and the branch point while faulting outside and in branch domain to determine whether the fault occurred in the branch line.Secondly,the difference between the initial travel wave at the beginning and end of the trunk line of the actual fault is compared with that of the branch point and the cable connection point,and the branch line fault criterion is combined to determine the fault section of the trunk line.Finally,a simple single and double-ended traveling wave integrated ranging method is proposed to determine the specific fault location.PSCAD simulation results show that the set of positioning method can more accurately select the fault line,and determine the fault location.