考虑配电变压器杂散电容效应的10 kV电缆线路分布式测距方法  

Distributed Ranging Method for 10 kV Cable Line Considering Stray Capacitance Effect of Distribution Transformer

作　　者：张利 ZHANG Li(Electric Power Branch,Shengli Petroleum Administration Co.,Ltd.,Dongying 257000,China)

机构地区：[1]胜利石油管理局有限公司电力分公司,山东东营257000

出　　处：《电工技术》2022年第8期125-128,共4页Electric Engineering

摘　　要：现有10 kV电缆线路故障测距方法主要利用配网自动化系统、故障指示器以及离线式行波测距与定位设备实现最终的故障定位,耗时耗力,延缓了故障查找与修复时间,而且电缆线路末端行波测距装置一般仅检测电压行波信号,无法获取线路末端电流行波信号,导致在某些故障情况下无法可靠测距。分析了典型10 kV电缆网络接地故障时的电压与电流行波特征及其在线路中(特别是环网柜、线路末端处)的折反射规律,提出了一种考虑配电变压器杂散电容效应的分布式测距方法。由于配电变压器存在相间杂散电容,高频行波在短时间内等效为短路状态,因此在线路末端也可以检测到电流行波信号。与传统的配电线路测距方法相比,该方法可以实现在配电母线和分支线路末端的任一位置检测到电压、电流行波信号,提高了测距的可靠性。The existing fault location methods for 10 kV cable lines mainly use distribution automation system,fault indicator and off-line traveling wave locating and locating equipment to achieve the final fault location,which is time-consuming and labor-consuming,and delays the time of fault detection and repair.Moreover,the traveling wave fault location device at the end of the line usually only detects the voltage traveling wave signal,and cannot obtain the current traveling wave at the end of the line,which leads to the failure of reliable fault location in some cases.In this paper,the characteristics of voltage and current traveling wave and the refraction law of typical 10 kV cable network grounding fault are analyzed,and a distributed fault location method considering stray capacitance effect of distribution transformer is proposed.Because of the stray capacitance between phases in distribution transformer,high frequency traveling wave will be equivalent to short-circuit state in a short time,and current traveling wave signal can also be detected at the end of the line.Compared with the traditional method of distribution line ranging,this method can detect voltage and current traveling wave signals at any position at the end of distribution bus and branch line,and improve the reliability of ranging.

关 键 词：电缆网络 小电流接地 行波 故障测距 分布式故障 

分 类 号：TM732[电气工程—电力系统及自动化]