基于暂态行波时频特征的输电线路故障检测与选相方法  

Fault Detection and Faulty Phase Determination of Transmission Lines Based on Time-Frequency Characteristics of Transient Travelling Waves

作　　者：林圣[1] 梅俊涛 陈双[1] 何正友[1] 钱清泉[1] 

机构地区：[1]西南交通大学电气工程学院,四川省成都市610031 [2]江西电力职业技术学院,江西省南昌市330032

出　　处：《电网技术》2012年第7期48-53,共6页Power System Technology

基　　金：国家自然科学基金项目(50877068);中央高校基本科研业务专项资金资助项目(SWJTU11ZT07)~~

摘　　要：基于暂态量的故障时刻检测与故障选相方法速度快、灵敏度高,符合发展超高速保护的要求。输电线路故障产生的暂态行波信号在时域上和频域上都包含了丰富的故障信息,首先利用小波的多分辨率分析对三相暂态电流行波进行分解并将其重构至不同频段;然后在一时频窗内定义信号的时频特征向量以充分反映信号的时频特征,并利用相关系数来刻画信号的时频特征及其变化规律,以此提出基于暂态行波时频特征的输电线路故障检测与故障选相方法。该方法的可靠性及适应性由基于PSCAD/EMTDC的仿真试验验证。仿真试验结果表明,基于时频特征的故障检测精度高,故障选相结果准确,且不受故障距离、故障时间、过渡电阻的影响,同时所需故障数据窗短,对实现超高速保护有积极的借鉴意义。In view of its high speed and high sensitivity,the fault location and faulty phase determination based on transient quantities can meet the requirement of developing ultra-high speed protection.Transient travelling wave signals,which are caused by faults occurred in transmission lines,contain abundant fault information in both time-and frequency-domain.Firstly,utilizing the multi-resolution analysis of wavelet the three-phase transient current travelling waves are decomposed and afterwards reconstructed to different frequency bands;than in a time-frequency window the time-frequency characteristic vectors are defined to fully reflect the time-frequency characteristics of the signal,and the time-frequency characteristics of the signal and their variation law are described by correlation coefficients,on this basis a method for fault detection and faulty phase determination of transmission lines based on time-frequency characteristics of transient travelling waves is proposed.Both reliability and adaptability of the proposed method are verified by the results of simulation experiments based on PSCAD/EMTDC.Simulation results show that the time-frequency characteristics based fault detection and faulty phase determination of transmission lines can provide accurate fault detection and faulty phase determination results which are not affected by fault distance,the moment when the fault occurred and transition resistance,besides the required data window is short.The proposed method is available for reference to the implementation of ultra-high speed protection.

关 键 词：暂态行波 时频特征 故障检测 故障选相 相关系数 

分 类 号：TM77[电气工程—电力系统及自动化]