摘要
模块化多电平换流器(modularmultilevelconverter,MMC)将在直流电网的发展中发挥重要作用,通过控制和拓扑的方式降低MMC中子模块电容电压纹波幅值,有望降低对模块电容器容值、体积、成本的需求,是实现直流系统换流器轻型化设计的必由之路。该文首先分析MMC中子模块电容电压的波动产生机理,揭示电压波动与相间环流的耦合作用机理;其次,对国内外学者在降低MMC电容电压纹波幅值方面的研究现状进行分类阐述,指出附加控制方法和改进拓扑方案各自的优缺点。最后,对MMC轻型化设计研究领域未来的研究方向进行展望,指出附加控制方案更具工程实用价值,为最大化降低电容电压纹波幅值,需要对不同的拓扑和控制类方案进行联合使用。
Modular multilevel converter(MMC) is playing an important role in the development of the HVDC grid. Reducing the capacitor voltage ripple amplitude of the MMC sub-module by additional control and topological improvements is expected to reduce the capacitance of the module capacitors and their volumes and costs, which is necessary to realize the lightweight design of the HVDC converter. This paper first analyzed the mechanism of the fluctuation of capacitor voltage in MMC sub-module and reveals the coupling mechanism of voltage fluctuations and the circulation currents among three phases. Secondly, the recent research achievements of the scholars in reducing the amplitudes of MMC capacitor voltage ripple were classified. Then the advantages and disadvantages of the existing additional control method and topological improvements were compared and pointed out. Finally, the future research topics with respect to the MMC lightweight design were discussed. It indicates that the additional control schemes are of larger engineering and practical value in HVDC system and the joint use of different control methods to maximize the reduction of the capacitor voltage ripple amplitudes needs more attention.
作者
许建中
李钰
陆锋
樊强
赵成勇
熊小玲
屈海涛
XU Jianzhong;LI Yu;LU Feng;FAN Qiang;ZHAO Chengyong;XIONG Xiaoling;QU Haitao(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources (North China Electric Power University),Changping District,Beijing 102206,China;C-EPRI Electric Power Engineering Co.,Ltd,Changping District,Beijing 102200,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2019年第2期571-584,共14页
Proceedings of the CSEE
基金
国家自然科学基金项目(51607065
51707065)
国家电网公司科技项目(52130A17003D)~~
关键词
模块化多电平换流器
子模块电容器
电压纹波
环流
降容
modular multilevel converter (MMC)
sub-module capacitors
voltage ripple
circulation current
capacitance reduction
