一种非隔离混合型模块化多电平直流互联变流器  

A Non-isolated Hybrid Modular Multilevel DC-DC Converter

作　　者：李明睿 李笑倩[1] 魏应冬[1] 李伟瑞 陆超[1] 任立 邵文君 LI Mingrui;LI Xiaoqian;WEI Yingdong;LI Weirui;LU Chao;REN Li;SHAO Wenjun(Department of Electrical Engineering,Tsinghua University,Haidian District,Beijing 100084,China;Tianjin Research Institute for Advanced Equipment,Tsinghua University,Dongli District,Tianjin 300300,China;State Grid Beijing Electric Power Company,Xicheng District,Beijing 100031,China)

机构地区：[1]清华大学电机系,北京市海淀区100084 [2]清华大学天津高端装备研究院,天津市东丽区300300 [3]国网北京市电力公司,北京市西城区100031

出　　处：《中国电机工程学报》2021年第19期6716-6723,共8页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51807105);国网北京市电力公司科技项目资助:配网三相不对称潮流补偿及控制方法研究(SGBJDK00KJJS1900089)。

摘　　要：针对直流电网不同电压等级直流线路互联、新能源直流送出及中压直流储能系统等典型应用场景,文中提出交错连接软开关混合型模块化多电平直流互联变流器。通过对由H桥变流链构成的"电力电子电抗器"中电流与斩波器开关的配合控制,实现了斩波器中全部串联电力电子开关器件的零电流转换,具有开关损耗小、易于动态均压的优点,特别适于采用晶闸管等半控型器件实现斩波变换;加之未采用隔离变压器且直流电抗器小,是一种适用于中、高电压等级,具有转换效率高,器件电压、电流应力小,成本低廉等优势的双向直流功率互联方案。文中描述该变流器的拓扑结构、运行原理与控制策略,进行基于PSCAD/EMTDC的电磁暂态仿真与基于动模样机的物理实验,验证变流器的原理特点及运行有效性,并与其他几类典型直流变流器进行对比,证明其在转换效率与经济成本等方面具有一定优势。This paper proposed a hybrid modular multilevel DC converter(HMMD) for DC grid interconnection, renewable energy DC delivery and medium voltage DC energy storage systems. All series power electronic switches in the chopper can realize zero-current transition(ZCT) by controlling the chopper and currents in power electronic reactors composed of H-bridge chain links. The power electronic switches have low switching losses, and dynamic voltage balancing can be easily achieved. Semi-controlled switch like thyristor is suitable for the chopper. Without the need of isolation transformer or large inductor, the HMMD offers many advantages in medium voltage and high voltage applications, including bidirectional power flow ability, high efficiency, low cost, and low voltage and current stresses. The topology, operation principle and control strategy of the HMMD were presented. Simulation results in PSCAD/EMTDC environment demonstrated the validity and characteristics of the converter. Compared with other DC-DC converters, the proposed HMMD has attractive capital cost and power loss.

关 键 词：直流互联变流器 直流电网 零电流转换 模块化多电平变流器 高压直流变换 

分 类 号：TM46[电气工程—电器]