Affiliation of Author(s):自动化学院
Journal:IET Power Electron.
Abstract:The submodule (SM) capacitance value of a modular multilevel converter (MMC) is so large that the reliability and cost of the MMC are affected. By existing methods of second-harmonic circulating current injection with a closed-loop control strategy, the SM capacitance value can be greatly reduced. However, the design of the SM capacitance value is not given, and extra loss is brought in. This study gives the design of the SM capacitance value when the second-harmonic circulating current is injected with a closed-loop control strategy. Then, an adaptive control method based on SM capacitor voltage fluctuation feedback is proposed to reduce the extra loss caused by the second-harmonic circulating current injection. In addition, for the case without SM capacitor voltage sensors, a method based on real-time calculation of the injected second-harmonic circulating current is proposed to reduce the extra loss without SM capacitor voltage sensors. Finally, the accuracy of the design and the validity of the proposed methods are verified by simulation and experimental results. © The Institution of Engineering and Technology 2019.
ISSN No.:1755-4535
Translation or Not:no
Date of Publication:2019-09-18
Co-author:Xiao Lan,Wang, Chuyang
Date of Publication:2019-09-18