Research on the longitudinal protection of a through-type cophase traction direct power supply system based on the empirical wavelet transform  

作　　者：Lu Li Zeduan Zhang Wang Cai Qikang Zhuang Guihong Bi Jian Deng Shilong Chen Xiaorui Kan 

机构地区：[1]Faculty of Electric Power Engineering,Kunming University of Science and Technology,Kunming 650500,P.R.China [2]Brunel University London,London UB83PH,United Kingdom [3]Yunnan Power Grid Co.,Ltd.,Kunming 650041,P.R.China

出　　处：《Global Energy Interconnection》2024年第2期206-216,共11页全球能源互联网（英文版）

基　　金：supported by the National Natural Science Foundation of China(51767012);Curriculum Ideological and Political Connotation Construction Project of Kunming University of Science and Technology(2021KS009);Kunming University of Science and Technology Online Open Course(MOOC)Construction Project(202107).

摘　　要：This paper proposes a longitudinal protection scheme utilizing empirical wavelet transform(EWT)for a through-type cophase traction direct power supply system,where both sides of a traction network line exhibit a distinctive boundary structure.This approach capitalizes on the boundary’s capacity to attenuate the high-frequency component of fault signals,resulting in a variation in the high-frequency transient energy ratio when faults occur inside or outside the line.During internal line faults,the high-frequency transient energy at the checkpoints located at both ends surpasses that of its neighboring lines.Conversely,for faults external to the line,the energy is lower compared to adjacent lines.EWT is employed to decompose the collected fault current signals,allowing access to the high-frequency transient energy.The longitudinal protection for the traction network line is established based on disparities between both ends of the traction network line and the high-frequency transient energy on either side of the boundary.Moreover,simulation verification through experimental results demonstrates the effectiveness of the proposed protection scheme across various initial fault angles,distances to faults,and fault transition resistances.

关 键 词：Through-type Cophase traction direct power supply system Traction network Empirical wavelet transform(EWT) Longitudinal protection 

分 类 号：U223.6[交通运输工程—道路与铁道工程] TM773[电气工程—电力系统及自动化]