摘要
对于“网孔结构”的多端直流电网而言,边界元件的缺失使其线路之间的电气距离大大减小,导致区内、区外故障的判别存在困难。对此,首先分析了行波在该类直流电网中的传播过程,根据故障线路与非故障线路两侧同名行波与异名行波首波头的衰减特性差异,引入相关分析法来表征不同行波之间的相关性。结合突变量能量启动判据,形成了一套适用于具有“网孔结构”的多端直流系统的纵联保护原理。仿真结果表明,所提出的保护原理具有良好的速动性及选择性,且拥有较强的抗过渡电阻能力和抗噪能力。
Lacking the boundary elements greatly reduces the electrical distance between the lines,which makes it difficult to distinguish internal fault and external fault.To solve this problem,this paper first analyzes the complex refraction and reflection phenomenon in the VSC-MTDC,and the attenuation difference between the homonymic traveling waves and anonymous traveling waves are analyzed.Based on the correlation analysis,above difference is expressed by this means.A novel protection scheme for meshed VSC-MTDC is proposed using correlation coefficient differential protection and the superimposed component energy start-up criterion.By means of simulation analysis,the proposed protection scheme works well under different fault conditions,and has good selectivity and speed.
作者
林湘宁
刘琦
范理想
郑宇超
童宁
李正天
LIN Xiangning;LIU Qi;FAN Lixiang;ZHENG Yuchao;TONG Ning;LI Zhengtian(State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology),Wuhan 430074,China)
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2020年第13期45-55,共11页
Power System Protection and Control
基金
国家电网公司科技项目资助(5100-201999331A-0-0-00)
中国博士后科学基金项目资助(2018M642838)。
