含边界元件的MMC-MTDC直流侧单端量故障辨识方法  

MMC-MTDC DC Side Single-Ended Quantity Fault Identification Method with Boundary Elements

作　　者：付华[1] 陈浩轩 李秀菊 陈润晶 Fu Hua;Chen Haoxuan;Li Xiuju;Chen Runjing(Faculty of Electrical and Control Engineering Liaoning Technical University,Huludao,125105,China;State Grid Huludao Power Supply Company,Huludao,125100,China;State Grid Dandong Power Supply Company,Dandong,118000,China)

机构地区：[1]辽宁工程技术大学电气与控制工程学院,葫芦岛125105 [2]国网葫芦岛供电公司,葫芦岛125100 [3]国网丹东供电公司,丹东118000

出　　处：《电工技术学报》2021年第1期215-226,共12页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51974151,71771111);辽宁省重点实验室基金(LJZS003)资助项目。

摘　　要：直流侧故障辨识是基于模块化多电平换流器(MMC)的多端直流输电(MTDC)系统急需解决的重大科学问题。分析直流线路的边界特性与极间耦合特性,提出一种基于单端暂态能量的故障辨识方法。通过区内、外故障的暂态特征以及方向元件,构建故障线路选择判据;并利用母线相连线路的方向元件和交流侧故障的暂态特性,构造母线故障识别判据;再根据两极低频电流差异,设计故障极判别判据。该方法能快速辨识直流侧故障,无需两端通信,能够满足MMCMTDC系统对辨识方法速动性与选择性的要求。最后结合张北四端柔性直流系统的PSCAD仿真模型,验证了所提方法在不同的故障类型、故障位置和过渡电阻下均能准确检测到故障,且具备一定的抗过渡电阻能力。DC-side fault identification is the major scientific issue that needs to be solved urgently for multi-terminal DC transmission(MTDC)system based on modular multilevel converter(MMC).This paper proposed a fault identification method based on the single-ended transient energy by analyzing the boundary characteristic and inter-pole coupling characteristic of the DC line.The fault line selection criterion was constructed by the transient characteristic of the internal fault and external fault and the directional element.And the bus fault identification criterion was achieved by the directional element of the bus-connected lines and the transient characteristic of AC-side fault.Then,the fault pole discrimination criterion was designed by the low-frequency current difference between two poles.The proposed method could quickly identify the DC-side fault without communication,which could satisfy the speed and selectivity requirement of the MMC-MTDC system.At last,the Zhangbei four-port flexible DC system is built in PSCAD and the accuracy of the proposed method is verified by simulation results of different fault type,fault location and transition resistance,as well as proving that the method has certain ability resisting transition resistance.

关 键 词：故障辨识 模块化多电平换流器 多端直流输电 暂态能量 方向元件 

分 类 号：TM721[电气工程—电力系统及自动化]