基于小波多分辨率分析的输电线距离保护  

Distance Protection for Transmission Lines Based on Wavelet Multi-Resolution Analysis

作　　者：刘兴茂[1] 

机构地区：[1]成都信息工程学院,成都610225

出　　处：《电测与仪表》2014年第2期50-53,90,共5页Electrical Measurement & Instrumentation

基　　金：成都信息工程学院科研基金资助项目(CRF201207)

摘　　要：输电线路故障后的暂态期间,通过微分方程算法估算的电阻、电抗呈现衰减振荡变化特征。为了实现距离继电器的快速、可靠动作,需要滤除其中包含的高频成分。为此,提出应用小波多分辨率分析技术处理微分方程算法结果的方法。将微分方程算法的结果构成序列,采用Daubechies小波对该序列进行多分辨率分析。序列经小波分解成低频的逼近成分和高频的细节成分,选取低频逼近成分,经重构后得到故障线路阻抗,实现线路故障后快速估算出具有较高精度的阻抗值。PSCAD/EMTDC仿真结果表明:该方法能可靠、快速动作,其性能受故障初始角、故障距离等因素的影响小。During the transient period after a fault in the transmission line occurs, the estimated resistance and reactance of faulty transmission line, which are obtained from differential equation algorithm （DEA）, show the characteristics of attenuate oscillating. In order to improve the performance of DEA based distance relaying, it is necessary to remove high frequency components from the estimates. A method which utilizes wavelet multi-resolution analysis technology is suggested to process the results estimated by DEA. The Daubechies wavelets are applied to analysis the sequences which consist of the results from DEA. The sequences are decomposed and emerged as approximations and details, and the estimated resistance and reactance are reconstructed from the approximations. Quick evaluation of the impedance after fault occurred is achieved with high accuracy. PSCAD/EMTDC simulation results show that the relay can trip rapidly and reliably, and its performance is little influenced by various factors such as different fault inception angles and fault distances.

关 键 词：小波多分辨率分析 微分方程算法 距离保护 输电线路 

分 类 号：TM77[电气工程—电力系统及自动化]