适用于直流配电网的测距式保护  

Fault Distance Estimation-Based Protection for DC Distribution Networks

作　　者：李猛 贾科 毕天姝 杨国生[2] 刘宇[3] 杨奇逊 

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),北京市昌平区102206 [2]中国电力科学研究院,北京市海淀区100192 [3]国家电力调度通信中心,北京市西城区100031

出　　处：《电网技术》2016年第3期719-724,共6页Power System Technology

基　　金：国家重点基础研究发展计划项目(973项目)(2012CB215206);国家自然科学基金项目(51407067;51222703);高等学校学科创新引智计划资助(B08013)~~

摘　　要：提出了一种测距式保护,以保障基于电压源换流器的直流配电网安全可靠运行。在概述直流配电网拓扑结构的基础上,分析了双极短路故障各阶段电气量特征,重点探讨了R-L模型算法用于直流线路测距时在变量获取方法和数值稳定性两方面存在的局限性,并相应提出了新型变量获取方法以及提高算法数值稳定性的办法。仿真结果验证了所提保护算法的可行性,保护动作时间在20 ms以内,在40 d B白噪声情况下,测距误差仍保持在1%以内,区外故障时可靠不动作。所提保护利用常规采样频率即可较好地满足直流配电网对保护速动性与选择性的需求。A protection algorithm is proposed to guarantee reliability of DC distribution networks based on voltage sourcedconverter（VSC）. Overviews of DC distribution topology and fault characteristics are presented. Feasibility of R-L model algorithm for DC distribution networks is analyzed. To decrease errors and increase numerical stabilities, a new variable acquisition method and a new fault distance estimation formula are proposed. Simulation results verify feasibility of the proposed protection. Its operation time is less than 20 ms and distance estimation error is within 1%. External faults can also be reliably distinguished. The proposed protection meets requirements of speed and selectivity with lower sampling frequency.

关 键 词：测距式保护 R-L模型算法 直流配电网 电压源换流器 变量获取方法 数值稳定性 

分 类 号：TM72[电气工程—电力系统及自动化]