Open AccessA level adjustment–based fault‐tolerant control strategy for hybrid MMC
Author(s) -
Liu Yiqi,
Jin Yonglin,
Zhang Jun,
Liu Yanchao,
Chen Jianlong
Publication year - 2021
Publication title -
international transactions on electrical energy systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 42
ISSN - 2050-7038
DOI - 10.1002/2050-7038.12963
Subject(s) - modular design , matlab , fault tolerance , fault (geology) , controller (irrigation) , engineering , voltage , topology (electrical circuits) , capacitor , control theory (sociology) , computer science , control (management) , electronic engineering , reliability engineering , electrical engineering , artificial intelligence , agronomy , seismology , biology , geology , operating system
Summary With the capability of DC fault ride‐through and the reduced cost, the hybrid modular multilevel converter (HMMC) is a promising topology for high‐voltage direct current (HVDC) applications. However, the complicated configuration of HMMCs with a large number and different types of submodules (SM) increases the risk of submodule failure. This paper proposes a novel HMMC submodule fault‐tolerant strategy by adjusting the number of inserted SMs of faulty phases. Then, based on the analysis of the SM voltage fluctuation, an SM capacitor voltage controller matched in coordination with the fault‐tolerant strategy is designed. By utilizing the negative voltage output full‐bridge submodules (FBSMs), this strategy can significantly improve the SM fault‐tolerant capability of the HMMC. Moreover, as compared to conventional fault‐tolerant strategies, the proposed strategy requires fewer components and can be easily implemented. Finally, the feasibility and performance of the proposed strategy are verified by the MATLAB/Simulink simulation experiment under different fault conditions and MMC systems.