Abstract
Full-bridge submodule (FBSM)-based modular multilevel converter (FB-MMC) or hybrid MMC (HYB-MMC) composed of FBSMs and half-bridge submodules are necessary in many applications. However, the arm energy fluctuation during reactive power exchange is very high, causing large sizes and high costs of submodule capacitors. Using the negative states of the FBSMs, the FB-, and HYB-MMCs can dynamically adjust the dc voltage, and this technique has been used in many commissioned projects. This study treats the dc voltage as a new dimension and proposes a new operation mode based on variable dc voltage for FB- or HYB-MMCs to reduce the arm energy fluctuations and submodule capacitance. The basic idea is to reduce the dc voltage in high reactive power and low active power conditions, thereby suppressing the arm energy fluctuations. Theoretical analysis shows that the energy fluctuation and submodule capacitance can be reduced by 30%–40%, and the valve cost can be reduced by 13%. Economic and technical comparison results show that the proposed approach can have similar reduction effects on the capacitance and valve cost, but has fewer technical limits. Simulation and experimental results verify the analysis.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
