基于断路器重合闸的柔性直流输电线路单端故障测距方法  

A single terminal fault location method for a DC transmission line based on circuit breaker reclosing

作　　者：赵冠琨 贾科 陈金锋 陈淼 毕天姝 ZHAO Guankun;JIA Ke;CHEN Jinfeng;CHEN Miao;BI Tianshu(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,(North China Electric Power University),Beijing 102206,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京102206

出　　处：《电力系统保护与控制》2021年第7期48-56,共9页Power System Protection and Control

基　　金：国家重点研发计划项目资助(2018YFB0904100);国家电网公司科技项目(SGHB0000KXJS1800685)。

摘　　要：高压柔性直流输电采用架空线路,运行环境复杂,难以避免故障。快速准确的故障定位可以缩短故障清除时间,对于快速恢复供电十分重要。现有测距算法依赖暂态波头辨识,受到干扰后测距精度会下降。针对上述问题,在线路分布参数模型基础上,在时域中通过电报方程计算线路沿线分布的电压和电流,进而根据故障点处电阻值相对稳定这一特性构成测距判据。由于输电线路两侧的直流断路器重合时间并不一致,此时先重合一侧的系统才会继续向故障点馈入短路电流,因此通过单端量便可实现测距。所提测距方法无需通信,适用于各种故障类型并且所需窗长较短,具有耐受过渡电阻和噪声的能力。最后利用PSCAD/EMTDC电磁暂态仿真软件搭建±500 kV多端柔性直流输电系统模型,仿真结果验证了所提测距算法的准确性和适用性。High voltage flexible DC transmission uses the overhead line.This makes it difficult to avoid faults in a complex environment.Fast and accurate fault location can shorten the time of fault clearing,something which is very important for fast power supply recovery.The existing ranging algorithms rely on transient wave head identification,and the ranging accuracy will decrease when disturbed.Based on a distribution parameter model,this paper calculates the voltage and current along the line through the telegraph equation in the time domain,and then forms the ranging criterion according to the feature that the resistance value at the fault point is relatively stable.Since the coincidence time of DC circuit breakers on both sides of the transmission line is not consistent,the system on the overlapping side will continue to feed the short-circuit current to the fault point.Therefore,ranging can be realized through a single terminal.The proposed ranging method requires no communication,which is suitable for various fault types and requires short window length,and can withstand transition resistance and noise.Finally,a four-terminal HVDC±500 kV model is built in PSCAD/EMTDC simulation software and the simulation results verify the accuracy and applicability of the proposed ranging algorithm.

关 键 词：直流输电线路 故障测距 直流断路器 分布参数模型 重合闸 

分 类 号：TM75[电气工程—电力系统及自动化] TM721.1