一种适用于中压直流系统的电平多级倍增MMC拓扑及其调制策略  

A Level Multiplication MMC Topology and Modulation Strategy for Medium Voltage DC System

作　　者：许同 王琛[1] 陶建业 王毅[1] 刘飞 王世斌 田旭 刘联涛 XU Tong;WANG Chen;TAO Jianye;WANG Yi;LIU Fei;WANG Shibin;TIAN Xu;LIU Liantao(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Baoding 071003,Hebei Province,China;Economic and Technical Research Institute of State Grid Qinghai Electric Power Company,Xining 810008,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),河北省保定市071003 [2]国网青海省电力公司经济技术研究院,西宁市810008

出　　处：《电力建设》2022年第5期40-49,共10页Electric Power Construction

基　　金：国家自然科学基金项目(52077079);河北省自然科学基金(E2021502048)。

摘　　要：受到电平数的限制,应用于中压直流系统的模块化多电平换流器(modular multilevel converter, MMC)难以兼顾较低的运行损耗和较高的电压质量。为此,设计了一种电平多级倍增模块化多电平换流器(level multiplication modular multilevel converter, LM-MMC)拓扑及其电平倍增调制(level multiplication modulation, LMM)策略。通过引入具备并联输出非整数电平的B型子模块,LM-MMC的输出电平可实现多级倍增。其次,根据排序结果轮换子模块的工作模式,可以有效均衡电容电压。此外,当LM-MMC拓扑应用LMM策略时,上下桥臂输出电平数目之和恒定,换流器的循环电流较低。最后,仿真模型和物理实验结果表明,适用于LM-MMC拓扑的LMM策略的运行损耗较低,且输出波形质量较高。Since the level number of modular multi-level converters(MMC) used in medium voltage DC systems is small, it is difficult to operate with lower operating losses and higher voltage quality. Thus, a level multiplication MMC(LM-MMC) topology and level multiplication modulation(LMM) strategy is designed. By introducing B-submodules with capability of parallel output non-integer level, the output level of LM-MMC can be multiplicated. Secondly, the operation mode of submodule is rotated according to the sorting result, which can effectively balance the capacitor voltages. In addition, when the LMM strategy is applied to the LM-MMC topology, the sum of output level in the upper and lower arms is constant, and the circulating current of the converter is lower. Finally, according to the simulation and physical experiment results, the operating loss of LMM strategy applied to the LM-MMC topology is lower, and the output waveform quality is higher.

关 键 词：电平倍增模块化多电平换流器(LM-MMC) 电平倍增调制(LMM) 电压质量 循环电流 运行损耗 

分 类 号：TM46[电气工程—电器]