基于故障暂态过程的半波长输电线路差动保护策略  

Fault Induced Transients Based Differential Protection Strategy for Half-wavelength Transmission Lines

作　　者：曹璞璘[1] 王登 范浩然 束洪春[1] 韩一鸣 杨博[1] 董俊[1] CAO Pulin;WANG Deng;FAN Haoran;SHU Hongchun;HAN Yiming;YANG Bo;DONG Jun(Faculty of Electric Power Engineering,Kunming University of Science and Technology,Kunming 650500,Yunnan Province,China)

机构地区：[1]昆明理工大学电力工程学院,云南省昆明市650500

出　　处：《中国电机工程学报》2022年第10期3587-3600,共14页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51977102,52167012)。

摘　　要：由于超长输电距离引起的分布电容较大,传统保护不能直接应用于半波长输电线路(half-wavelength transmission line,HWTL)。该文提出一种基于故障暂态过程的新型保护策略,利用方向行波原理对半波长输电线路进行保护。为了识别故障方向,对半波长输电线路各终端的方向行波进行电压和电流的计算,并以10kHz的采样频率记录。随后,采用低采样频率的暂态波形积分来代替行波波头的精确检测。然后,利用短时窗暂态波形积分的商值来判别区内故障和区外故障。如果故障发生在半波长输电线路,则两个终端的商值接近1。相反,区外故障的情况下,则终端的商值远大于1。最后,通过PSCAD/EMTDC进行仿真,验证了所提出的差动保护策略的鲁棒性。Due to the large distributed capacitance induced by extra-long transmission distance,traditional protection cannot be directly applied on half-wavelength transmission lines(HWTL).This paper proposed a novel differential protection strategy based on fault caused transients for HWTL with the principle of directional wave.In order to identify the direction of faults,the directional waves at each terminal of HWTL were calculated by both voltage and current,and recorded by a sampling frequency of 10kHz.Subsequently,integration of transient waveforms with a low sampling frequency was applied to replace the accurate detection of traveling wave front.Then,the quotient of integral of transients in a short time window was applied to distinguish internal fault and external fault.If the fault occurs in HWTL,quotients of both terminals approximate to one.Conversely,the quotient of one terminal is quite larger than that in the case of internal fault.At last,the robustness of the proposed differential protection strategy has been validated by simulation via PSCAD/EMTDC.

关 键 词：半波长输电线路 差动保护 方向行波 衰减系数 

分 类 号：TM73[电气工程—电力系统及自动化]