Abstract

The circulating current of modular multilevel converter (MMC) is an inherent phenomenon. The existing circulating current analysis methods have mainly considered the power losses and the submodule (SM) capacitor voltage. Under low-frequency operation, MMC SM has a larger capacitor voltage ripple, and this paper proposes a novel circulating current injection method to reduce the SM capacitor voltage ripple. The method is based on injecting a circulating current, which is easily derived by the instantaneous information of MMC, within the phase to attenuate the lower frequency arm powers. And, it omits using an extensive lookup table and injecting a common-mode voltage, thus simplifies the control and avoids causing over-modulation. In addition, a mathematical analysis model is built and it reveals the impact on the SM capacitor voltage ripple. The effectiveness of the introduced circulating current injection method is demonstrated by the experimental results.

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 call

Disclaimer: 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.