GIS局部放电定位的频域时差读取方法  

Method of Time Difference Reading Based on Frequency Domain for PD Location in GIS

作　　者：幸琳[1] 姚陈果[1] 孙才新[1] 

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030

出　　处：《高压电器》2011年第6期13-18,共6页High Voltage Apparatus

基　　金：国家重点基础研究发展计划(973计划)(2009CB724506);国家重点实验室自主研究课题(2007DA10512709104);重庆市科技攻关计划(院士专项)(CSCT2010BC3003)~~

摘　　要：局放(PD)源定位通常依赖于局放信号时域波形获取时差,然而,当信噪比(SNR)很低或者PD信号的初始脉冲较小时,难以获得PD信号的起始脉冲时间。笔者摒弃对时域PD信号分析,结合GIS中电磁波的传播模式特性,通过FFT变换将时域波形转换为频域PD信号进而在频域研究,提出一种精确获取时差的新算法。采用时域有限差分法(FDTI))建立模拟组合绝缘电器并获取PD信号,进行理论PD时差获取及新算法抗干扰性能的分析研究;同时在模拟GIS试验平台上分别采用内置天线和外置天线检测PD信号以获取实测PD时差,并分析影响时差精度的内在因素。仿真和试验结果表明,频域时差算法能有效获取PD信号时差,并且具有很强的抗干扰能力。The time difference of a UHF partial discharge（PD） signal for PD location is always calculated from the time domain waveforms, however, when the signal to noise ratio（SNR） is low or the initial pulse of the PD single is small, it＇s difficult to obtain the arrive time of the initial pulse. This paper proposes a new algorithm for achieving the time difference, which is combined with the characteristics of EM-wave modes in GIS and changes the PD signals from time domain to frequency domain by using fast Fourier transformation. A simulation model is built by the finite- difference time-domain （FDTD） method for obtaining the theoretical time difference of PD signals and analyzing the anti-interference ability of the new algorithm. On the experimental GIS model both internal and external antennas are used to obtain the time difference of real PD singles so as to analyze the internal factors of impacting PD location. Simulation and experiment indicate that the proposed algorithm can obtain the time difference of PD signals in GIS with strong anti-interference ability.

关 键 词：局放源定位 时差 气体绝缘开关设备(GIS) 傅里叶变换 

分 类 号：TM595[电气工程—电器]