直流微网接地方式及新型保护原理  

A Research of Grounding Mode and New Protection Principle for DC Microgrids

作　　者：薛士敏[1] 齐金龙[1] 刘冲[1] 廉杰 

机构地区：[1]智能电网教育部重点实验室(天津大学)

出　　处：《电网技术》2018年第1期48-55,共8页Power System Technology

基　　金：国家自然科学基金项目(51577129);国家863高技术基金项目(2015AA050102);天津市自然科学基金项目(14JCYBJC21000)~~

摘　　要：伴随着新能源的推广和直流负荷的普及,直流微网因其具有提高分布式电源消纳效率的天然优势,契合未来电网环境清洁化、运行智能化的发展趋势,受到了广泛的关注和研究。在有关直流微网的众多研究方向中,接地方式的选取决定了接地故障特征,从而影响到保护方案的选择与整定,但学术界对直流微网接地的研究仍处于起步阶段。作者将通过对比多种接地方式的优缺点、应用价值、经济性等因素,选择最优的接地方案,在此基础上,设计在大过渡电阻接地故障的情景下仍能可靠动作的保护判据,并通过电阻限流器的接入消除保护死区。最后将设计一种横联保护原理,分析该保护方案在各种网络结构和不同故障位置时的适用性,并通过仿真验证保护方案的有效性。With promotion of renewable energy and popularization of DC loads, DC microgrids is able to improve efficiency of distributed generation and meet development tendency of future power grids requiring clean environment and smart operation, draws more and more attentions. In many research directions of DC microgrids, grounding mode determines grounding fault feature, consequently influencing choice and setting of protection scheme. However, study of DC microgrids grounding mode is still in initial stage. This paper selects optimal grounding schemes by compare advantages and disadvantages, application value, and economy of a various grounding modes. On this basis, a protection criterion acting reliably in situation of large transition resistance is designed, and a resistance current limiter is applied to eliminate dead zone of protective relays. Finally, a transverse protection is proposed and its applicability in different network structures and fault locations is analyzed. Validity of the protection scheme is verified with simulations.

关 键 词：直流微网 接地方式 保护原理 保护死区 

分 类 号：TM76[电气工程—电力系统及自动化]