摘要
为解决现有雷电定位系统所测电磁波因波形传播延时和地形传播延时影响雷电定位准确度的问题,根据输电线遭受雷击时向两端变电站母线运动的行波和行波测距理论,提出了一种改进的双端行波输电线雷击点定位法。首先利用小波变换提取在线路两端母线处采集到的雷击入射行波、母线反射行波或雷击点反射行波信号的波头特征点,进而准确确定行波的到达时刻,然后建立一个只包含距离和时间的函数解出雷击点的位置而不受波速影响。该方法不需事先确定行波波速,与传统行波定位法相比,消除了波速的不确定性带来的定位误差。大量PSCAD/EMTDC仿真结果表明,该法的雷击点定位误差<300m。
Accurate location of lightning strikes on the transmission line is very important for the immediate recovery of power supply and the lightning strike protection. For that purpose, the lightning strike location system is widely used both in China and abroad. However, according to the research data the accuracy of this kind of location system is affected by the delay of the detected electromagnetic wave due to its waveform and the surrounding terrain, and its measurement error is between 1 km and 3 km, which is larger than what we expected. Considering that lightning strike will generate traveling wave toward both sides of the transmission line, combining the existing traveling wave theory this paper presents an improved double terminal traveling wave location method for the location of lightning strikes happened on the transmission line. First of all, collect the signals of the traveling waves from the point of strike, echo from the point of strike or echo from the opposite bus bar at both sides of the transmission line. Then use the wavelet transform to extract the characteristic points of the wave front signals in order to accurately measure the arrival times of the traveling wave fronts. At last a function involving only time and distance can be made and the point of strike is consequently obtained from the function. Compared with the traditional traveling wave location method, this new method doesn＇t need to determine the velocity of the traveling wave before measurement, so the measurement error caused by the uncertainty of the wave velocity can be avoid. A large amount of PSCAD/EMTDC simulation results show that this new method is efficient in locating the lightning strike and its error is less than 300 m.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2007年第1期86-90,共5页
High Voltage Engineering
关键词
输电线路
雷击点定位
小波变换
双端法
行波
波速
transmission line
lightning strike location
wavelet transform
double terminal method
traveling wave
wave velocity
