摘要
从提高特高压直流输电线路保护可靠性的角度出发,提出一种基于突变量能量波形特征的特高压直流输电线路单端保护方法。利用叠加原理分析故障后突变量能量,发现系统正常运行时,突变量能量为零。直流输电线路发生故障后,突变量能量具有明显变化,据此构造直流输电线路保护启动判据。进一步分析直流滤波器和平波电抗器对突变量能量波形的影响,发现二者的平滑作用使能量分散造成波形变缓,利用标准差系数刻画突变量能量波形的波动特性,据此构造直流输电线路区内、外故障识别判据。利用正、负极标准差系数之比构造故障选极判据,进而实现故障极全线速动保护。仿真结果表明,该保护方法能可靠地区分直流线路区内、外故障,实现故障选极,保护特高压直流线路全长。
From the perspective of improving the reliability of UHVDC transmission line protection,a single-ended protection method for UHVDC transmission line based on the characteristics of sudden energy waveform is proposed.The superposition principle is used to analyze the energy of the sudden change after the fault.It is found that the sudden energy of the system is zero when the system is in normal operation.After the fault occurs in the DC transmission line,the sudden change energy has obvious changes,and the starting criterion of the protection of the DC transmission line is constructed accordingly.Further analysis of the influence of the DC filter and the smoothing reactor on the sudden energy waveform is done,it is found that their smoothing effect causes the energy dispersed and the waveform flat.The standard deviation coefficient is used to characterize the fluctuation characteristics of the sudden energy waveform,and the distinguishing criterion of internal area fault and external area fault for DC transmission line is constructed accordingly.The fault pole selection criterion is constructed by using the ratio of the standard deviation coefficients of the positive and negative poles,thereby realizing the full-line quick-action protection of the fault pole.The simulation results show that the protection method can reliably distinguish inner and outer faults of the DC line,select fault pole,and protect the full length of UHVDC lines.
作者
王永进
樊艳芳
李自乾
WANG Yongjin;FAN Yanfang;LI Ziqian(School of Electrical Engineering,Xinjiang University,Urumqi 830047,China;Pingliang Power Supply Company,State Grid Gansu Electric Power Company,Pingliang 744000,China)
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2019年第21期55-61,共7页
Power System Protection and Control
基金
新疆维吾尔自治区自然科学基金联合项目资助(2017D01C028)~~
关键词
叠加原理
突变量能量
标准差系数
区内外故障
故障选极
superposition principle
mutation energy
standard deviation coefficient
internal area fault and external area fault
fault pole selection
