电弧反射电缆故障测距装置脉冲发射时刻选择算法  

Pulse Emitting Time Selection Algorithm for Cable Fault Locator with Arc Reflection

作　　者：李峰[1] 徐丙垠[2] 

机构地区：[1]合肥工业大学仪器科学与光电工程学院,安徽省合肥市230009 [2]山东理工大学电气与电子工程学院,山东省淄博市255049

出　　处：《电力系统自动化》2011年第13期88-91,共4页Automation of Electric Power Systems

摘　　要：电弧反射法(ARM)是一种广泛应用的电缆故障测距方法。由于不清楚测试过程中电缆故障点电弧电阻的动态特性,因此施加测试脉冲时脉冲发射时刻的选择比较困难。分析了ARM测距装置放电过程中的电压和电流特性,以及故障点的电弧电阻特性。论证了在直流电弧放电阶段电弧电阻较低而且稳定,是发射脉冲的最佳时段。据此提出根据电流最大值和故障点电弧电阻的动态特性选择脉冲发射时刻的算法。该方法仅需计算ARM测距装置电压采样数据的方差,即可判断故障电弧电阻的状态,进而确定脉冲发射时刻。装置不需要延弧器,对电弧不稳定故障也能测距。试验数据验证了该方法的正确性。Arc reflection method （ARM） is a kind of power cable fault locating method widely used nowadays. It is difficult to choose exact time for test pulse emitting into the cable during cable fault testing and fault arcing, because the arc resistance dynamic characteristic is not clearly known. Therefore the characteristics of voltage, current of ARM fault locating device and arc resistance at fault location during the discharge process are analyzed. It proves that in period of DC arc discharge arc resistance on the fault spot is lower and stable as a whole, which maintains a relative long time and is the best period of time for pulse emitting into the tested cable. A new choosing pulse emitting time algorithm based on maximum current and arc resistance dynamic characteristic on fault spot is proposed. This method only needs to calculate variance of voltage sampling of ARM and to judge the state of fault arc resistance so as to choose a pulse emitting time. In addition, the intermittent fault can also be located without using arc prolong device. Recorded experiment data proved correctness of the proposed technique.

关 键 词：电弧电阻 电弧反射法 脉冲发射时刻 故障测距 二次脉冲法 

分 类 号：TM726[电气工程—电力系统及自动化]