摘要
针对目前柔性直流配电线路保护所存在的问题,尤其是保护方案耐受高阻故障能力较弱的问题,该文通过分析区内金属性故障、经过渡电阻故障与区外故障电压特征,对一定时间窗内的电流变化量、电压变化量进行时域加权提取区内外故障差异,利用电流、电压时域加权量构造保护判据。在此基础上,提出了一种基于单端电气量时域加权特征的柔性直流配电线路保护方案。仿真结果表明,该方案能在0.3ms内可靠识别区内金属性故障,0.4ms内可靠识别区内高阻故障(过渡电阻达20Ω)。该方案不受系统运行方式影响,对采样频率的要求不高,工程实用性强。
In view of the problems existing in the flexible DC distribution line protection,especially the weak ability of the protection scheme to withstand high resistance faults,this paper analyzes the differences in the voltage characteristics between the in-area metal and high resistance faults and the out-of-area faults.The fault differences extracted inside and outside the area by time-domain weighting the current and voltage variations within a certain time window,and the protection criteria art constructed by using the time-domain weighting of current and voltage.On this basis,a protection scheme for the flexible DC distribution lines based on the time-domain weighted features of the single-ended electrical quantities is proposed.The simulation results show that the scheme reliably identifies a metal fault in the area within 0.3ms and a high resistance fault in the area within 0.4ms(with the transition resistance is up to 20Ω).This scheme is proved to have a strong engineering practicability with out being affected by the system operation and high requirements for the sampling frequency.
作者
王正茂
梁英
曹虹
余越
WANG Zhengmao;LIANG Ying;CAO Hong;YU Yue(China Electric Power Research Institute,Haidian District,Beijing 100192,China)
出处
《电网技术》
EI
CSCD
北大核心
2023年第5期1845-1854,共10页
Power System Technology
基金
国家自然科学基金委员会–国际(地区)合作与交流项目(项目批准号52061635104,交直流柔性互联的城市能源系统协调运行与故障恢复)。
关键词
柔性直流系统
直流配电网
故障特征
单端量保护
时域加权
flexible DC system
DC distribution network
fault characteristics
single ended protection
time-domain weighting
