摘要
针对零模波速随频率变化大的问题,提出利用零模行波波速特性求取波速的方法,并将其应用到配电网单相接地故障测距中。将行波信号分解到小波各个频带内,不同的频带信号会产生不同的衰减和相移,但各个频带上初始行波波速都会大于第1次反射波波速。利用零模行波波速的这种特性,选取初始行波波速与第1次反射波波速最相近的特征频带。在该频带下利用线模行波和零模行波波头一一对应关系求取第一次反射波波速,将其代入基于零模和线模波速差的测距公式,得到精确的故障距离。利用PSCAD/EMTDC搭建仿真模型,对不同的故障情况进行仿真,结果证实了所提方法的有效性和准确性。
Aiming at the problem of zero-mode wave velocity varying fast with the frequency, this paper represented a scheme of single phase-to-ground fault location for distribution networks by using the traveling wave velocity property extract zero-mode traveling wave velocity. Traveling wave signals were decomposed into multiple frequency bands in which signals have different signal attenuation and phase shift, but all the initial traveling wave velocity were greater than the first reflection traveling wave velocity on every band. By using this property of zero-mode traveling wave velocity, a band was selected as the characteristic band in which the initial traveling wave velocity and the first reflection traveling wave velocity was the most similar. In the characteristic frequency band, the first reflection traveling wave velocity was obtained by one-to-one correspondence between aerial-mode traveling wave head and zero-mode traveling wave head, and then the accurate fault distance was got by fault location formula based on wave velocity difference. Finally, a simulation model was built by PSCAD/EMTDC to simulate different fault conditions, simulation results show that the proposed method is effective and accurate.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2015年第S1期93-98,共6页
Proceedings of the CSEE
基金
国家自然科学基金项目(61433004)
中央高校基本科研业务费项目(N130604001)~~
关键词
配电网
故障测距
零模行波波速
特征频带
波速差
distribution network
fault location
zero-mode traveling wave velocity
characteristic frequency band
wave velocity difference
