基于半桥型MMC的柔性直流电网故障限流方法综述  

Review of the fault current limiting approaches for a flexible DC grid based on a half-bridge MMC

作　　者：陈磊[1] 何慧雯 王磊 李国城 陈红坤[1] CHEN Lei;HE Huiwen;WANG Lei;LI Guocheng;CHEN Hongkun(School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China;China Electric Power Research Institute,Wuhan 430074,China)

机构地区：[1]武汉大学电气与自动化学院,湖北武汉430072 [2]中国电力科学研究院有限公司,湖北武汉430074

出　　处：《电力系统保护与控制》2021年第21期175-186,共12页Power System Protection and Control

基　　金：国家电网公司总部科技项目资助“LCC-VSC混合直流输电系统过电压与绝缘配合研究”(SGTYHT/16-JS-198)。

摘　　要：现阶段投运的柔性直流电网通常采用半桥型模块化多电平变换器(Modular Multilevel Converter,MMC),具有惯量低、阻尼小等基本特征,存在故障演变迅速、设备过流能力弱、故障电流开断难等技术挑战。妥善处理柔性直流电网的故障电流限制问题,具有重要的理论价值与现实意义。针对于此,阐明了柔性直流输电技术的发展需求和引入故障限流措施的必要性,系统地总结了国内外研究现状。依据实体限流和虚体限流技术方案进行了分类整理和性能比较,论述了两类限流措施的技术优势及不足之处。最后,提出了半桥型MMC柔性直流电网故障限流方法的未来发展方向,探讨了其中的难点问题和解决思路。Currently,the flexible Direct Current(DC)grid usually adopts the half-bridge Modular Multilevel Converter(MMC),and it has basic characteristics such as low inertia and small damping.The technical challenges including rapid fault development,weak overcurrent tolerance and insufficient current breaking ability should be carefully addressed.It is of significance to properly handle the fault current limiting issues of the flexible DC grid.In this paper,the development requirements of flexible DC transmission technology and the necessity of introducing fault current limiting approaches are stated.Domestic and foreign research results are systematically summarized.According to the classification of the actual and virtual fault current limiting schemes,their technical advantages and disadvantages are compared and analysed.Finally,the probable development direction of the fault current limiting approaches for the flexible DC grid based on half-bridge MMC are suggested,and potential problems as well as solutions are discussed.

关 键 词：柔性直流电网 故障限流方法 半桥型MMC 虚实融合限流 混合型直流限流器 

分 类 号：TM721.1[电气工程—电力系统及自动化]