含柔性直流接入的架空线-电缆混合线路单端故障测距方法  

Single-ended Fault Location Method for Overhead Cable Mixed Lines Connected with MMC-HVDC System

作　　者：薛士敏[1] 陆俊弛 王守相[1] 孙亚冰 刘存甲 刘白冰 XUE Shimin;LU Junchi;WANG Shouxiang;SUN Yabing;LIU Cunjia;LIU Baibing(Key Laboratory of the Ministry of Education on Smart Power Grids(Tianjin University),Tianjin 300072,China;Dalian Electric Power Supply Company of State Grid Liaoning Electric Power Co.,Ltd.,Dalian 116000,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]国网辽宁省电力有限公司大连供电公司,辽宁省大连市116000

出　　处：《电力系统自动化》2020年第22期103-111,共9页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2016YFB0900900);国家自然科学基金资助项目(51977144)。

摘　　要：准确可靠的故障测距技术对含有柔性直流接入的交流架空线-电缆混合线路的故障恢复至关重要。模块化多电平换流器配置的控制策略决定了其输出特性,将会影响现有故障测距方法的测距性能。考虑换流器控制策略对混合线路故障复合序网的影响,提出一种新型的单端故障测距方法。换流器配置的负序电流抑制策略使故障后的负序网络仅包含传统交流侧,形成的单端网络使混合线路沿线集合电压和负序电流仅在故障点处同相位,利用其独特的边界条件,根据故障点处相位差函数最小的特点实现故障测距。在PSCAD/EMTDC上搭建柔性交直流混合输电系统模型,大量的仿真结果验证了该测距方法的有效性,以及在测距精度、抗过渡电阻能力和抗干扰能力等方面的优势。Accurate and reliable fault location technique is essential to the fault recovery of the AC overhead cable mixed lines connected with a modular multilevel converter based high-voltage direct current(MMC-HVDC)system.Control strategies for the configuration of MMC determine its output characteristics and will affect the performance of the existing fault location methods.Considering the influence of the converter control strategies on the fault compound sequence network of the mixed lines,a novel single-ended fault location method is proposed.Due to the influence of the negative-sequence current restraint strategy configurated in MMC,the negative-sequence network only contains the traditional AC side after the fault.The formed single-ended network makes the voltage set and the negative-sequence current along the mixed lines be in the same phase merely at the fault point.By using this unique boundary condition,the fault location can be realized according to the characteristic that the phase difference function is smallest at the fault point.A model of a flexible AC/DC hybrid transmission system is built in PSCAD/EMTDC.A large number of simulation results verify the effectiveness of the proposed method and its advantages in location accuracy,transition resistance and interference endurance ability.

关 键 词：柔性直流 混合线路 故障测距 负序电流抑制策略 单端电气量 

分 类 号：TM75[电气工程—电力系统及自动化] TM721.1