基于Marti模型的柔性直流输电系统纵联行波差动保护  

Longitudinal Travelling Wave Differential Protection for Flexible HVDC System Based on Marti Model

作　　者：薛士敏[1] 孙亚冰 刘白冰 陆俊弛 XUE Shimin;SUN Yabing;LIU Baibing;LU Junchi(Key Laboratory of Smart Grid of Ministry of Education(Tianjin University),Nankai District,Tianjin 300072,China)

机构地区：[1]智能电网教育部重点实验室(天津大学)

出　　处：《中国电机工程学报》2019年第21期6288-6299,共12页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2016YFB0900900)~~

摘　　要：柔性直流输电系统越来越多地应用于新能源并网,远距离、大容量电力传输及交流系统异步互联等方面。直流故障的快速、可靠识别是柔性直流输电系统发展亟待解决的问题。该文从线路模型出发,以行波理论和Marti模型为基础,定量分析了故障后模块化多电平换流器(modularmultilevel converter,MMC)闭锁前的故障特征。结合行波保护速动性和纵联差动保护可靠性的特点,提出纵联行波差动保护新原理。该原理满足柔性直流输电系统保护的快速性要求,耐受过渡电阻能力强、抗干扰能力强、易于整定和实现。通过PSCAD/EMTDC大量仿真,验证了该保护原理的适用性。Flexible high voltage direct current(HVDC) transmission system is increasingly applied to new energy grid connection, long-distance, high-capacity power transmission and AC system asynchronous interconnection. Fast and reliable identification of DC fault is a key problem in the development of flexible HVDC system. Based on the traveling wave theory and Marti model, The fault characteristics of modular multilevel converter(MMC) before blocking in DC fault was analyzed quantitatively, and a new principle of longitudinal traveling wave differential protection combined with the speed of traveling wave protection and reliability of longitudinal differential protection was proposed. This principle not only satisfies the fast protection requirements of flexible HVDC system, but also has the advantages of high fault resistance tolerance, strong anti-interference ability and easy to realize. The applicability of the protection principle was verified through large amount of simulation on PSCAD/EMTDC.

关 键 词：柔性直流输电 直流故障 模块化多电平换流器 Marti模型 纵联行波差动保护 

分 类 号：TM77[电气工程—电力系统及自动化]