嵌套型MMC的数学模型与故障特性分析  

Analysis of Mathematical Model and Fault Characteristics of Embedded MMC

作　　者：朱雯清 付丰豪 赵西贝 赵成勇 ZHU Wenqing;FU Fenghao;ZHAO Xibei;ZHAO Chengyong(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,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),北京市昌平区102206

出　　处：《电网技术》2023年第3期1242-1249,共8页Power System Technology

基　　金：国家自然科学基金项目(51777072)。

摘　　要：半全混合型模块化多电平换流器(hybrid modular multi-level converter,hybrid-MMC)能够实现无闭锁故障穿越,但是其全桥子模块比例必须达到50%以上,如何进一步降低成本具有重要的工程价值。基于嵌套式全桥阀段的嵌套型MMC(embedded full bridge modular multi-level converter,EFB-MMC)同样具有无闭锁故障穿越能力,但是其机理分析与故障穿越特性还需要进一步深入研究。该文从半全混合型MMC与EFB-MMC的拓扑结构出发,介绍2种方案的故障穿越机理;根据EFB-MMC的故障清除特性,给出了不同时段故障电流的表达式,并在仿真中验证。在双端系统中对比了2种方案在故障工况下的故障清除特性和恢复过程,并比较两者的投资成本和损耗差异。结果表明EFB-MMC与半全混合型MMC的故障清除效果相近,但是更具备成本优势,具备进一步研究价值。Hybrid Modular Multi-level Converter(hybrid-MMC) can achieve non-blocking fault ride-through,but the proportion of its full bridge sub-modules must reach more than 50%. How to further reduce the cost has important engineering value. The embedded full bridge modular multi-level converter(EFB-MMC) also has the fault ride through capability, but its mechanism analysis and non-blocking ride-through characteristics need further researches. Starting from the topological structure of the hybrid MMC and the EFB-MMC, this paper introduces the fault clearing mechanism of the two schemes. According to the fault clearing characteristics of the EFB-MMC, the expressions of the fault currents are given and verified by simulation. The fault clearing characteristics and recovery processes of the two schemes are compared in a two-terminal system, and so are their investment costs and losses. The results show that the EFB-MMC has the similar fault clearing effects with the half-full hybrid MMC, but has more cost advantages, valuable for further researches.

关 键 词：嵌套型MMC 半全混合型MMC 直流保护 故障穿越 

分 类 号：TM721[电气工程—电力系统及自动化]