基于重合直流断路器残余电流开关的柔性直流电网故障测距  

Fault Location for Flexible DC Grid Based on Reclosing Residual Current Breaker of DC Circuit Breaker

作　　者：李斌[1] 毛琦扬 何佳伟[1] 于洋 邵庆祝 李晔[1] LI Bin;MAO Qiyang;HE Jiawei;YU Yang;SHAO Qingzhu;LI Ye(Key Laboratory of the Ministry of Education on Smart Power Grids(Tianjin University),Tianjin 300072,China;State Grid Anhui Electric Power Co.,Ltd.,Hefei 230061,China)

机构地区：[1]智能电网教育部重点实验室(天津大学),天津市300072 [2]国网安徽省电力有限公司,安徽省合肥市230061

出　　处：《电力系统自动化》2021年第10期140-148,共9页Automation of Electric Power Systems

基　　金：国家电网公司科技项目(适应高比例新能源接入的交直流混联电网的暂态量保护研究,SGAH0000TKJS1900278)。

摘　　要：精确故障测距是确保电力系统故障快速排查清除的关键技术,其中基于行波固有频率的故障测距方法在常规直流输电系统中具有突出的技术优势。但是通过分析发现,柔性直流电网故障行波固有主频率低、可利用数据窗短,导致基于固有频率主成分的测距算法存在较大误差。针对上述问题,提出在重合闸期间重合残余电流开关创造足够长的暂态数据窗。同时,提出了主/次频迭代计算/校验式测距算法。在应用于柔性直流电网时,与传统利用故障初期固有主频实现故障测距的方法相比,所提测距方法能够显著提升故障测距精度,并且消除多重信号分类算法虚假谱峰现象导致的测距偏差问题。大量仿真算例验证了所提方法的可行性与优越性。Accurate fault location is the key technology for ensuring fast fault checking and clearing in power systems. The fault location method based on traveling-wave natural frequency has significant technical advantages in the line commutated converter based high voltage direct current(LCC-HVDC) system. However, through the analysis, it is found that the natural primary frequency of the fault traveling wave in the voltage source converter based HVDC(VSC-HVDC) grid is very low and the available data window is very short, which results in a large error for the location method based on the main component of natural frequency.Aiming at the above issue, it is proposed to reclose the residual current breaker(RCB) during reclosing period to create a sufficient transient data window. In addition, the fault location method based on primary/secondary frequency iterative calculation and verification is proposed. Compared with the traditional fault location method using the natural frequency at the beginning of the fault, the proposed method can significantly improve the fault location accuracy in VSC-HVDC grids. Moreover, the location deviation problem caused by the false spectral peak phenomenon of the multiple signal classification(MUSIC) algorithm is also avoided. Finally, a large number of simulation cases are carried out to verify the feasibility and superiority of the proposed method.

关 键 词：柔性直流电网 故障测距 直流断路器 固有频率 

分 类 号：TM561[电气工程—电器] TM721.1