Abstract
Modular multilevel converters (MMCs) become increasingly attractive in high-voltage dc (HVDC) transmission systems. However, the internal poorly damped characteristic can easily lead to low-frequency harmonic resonance, affecting the stability of MMC. In this study, the equivalent model of MMC is established to reveal the low-frequency harmonic resonance, including intrinsic harmonic resonance and potential harmonic resonance. To suppress the harmonic resonance, a circulating current suppressing method based on active damping is proposed to improve the internal damped characteristic. In order to enhance the control effectiveness, the circulating current reference is modified through a dual feedback closed-loop control involving arm voltages and currents as well as the power feedforward loop in the proposed suppression strategy. Proper parameters are designed to apply the reasonable damping characteristic of MMC. Finally, the proposed method is implemented and verified with an MMC-HVDC system in the RT-LAB simulator platform.
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.
