Capacitor Voltage Control and Harmonic Suppression of Modular Multilevel Converter

DOI

10.2991/978-94-6463-986-5_83How to use a DOI?

Keywords

Modular Multilevel Converter; PI control; Nearest Level Modulation

Abstract

The Modular Multilevel Converter (MMC) utilizes cascaded submodules to form a converter. As the number of submodules increases, higher output voltages can be achieved, making them suitable for medium and high voltage applications. They offer advantages such as low losses, high transmission efficiency, low switching losses, and reduced output harmonics. This paper investigates an MMC based on half-bridge submodules. Capacitor voltage control utilizes a combination of nearest-level approximation modulation and capacitor voltage balancing, employing a bubble sorting algorithm. This PI controller based on a feedback mechanism, the problem of circulating currents was solved by removing the coupling between the two feedback loops and obtaining two separate closed-loop control systems, the external control loop and the internal control loop. The results show that the circulating current is more stable, the distortion of the bridge current is reduced from 10.75% to 3.77%, the double-frequency content is greatly reduced. The simulation model was built with MATLAB-Simulink. The circulating current suppression effect is good, and the capacitor voltage waveform is stable. After the circulating current is suppressed, the rated current capacity of the power switching device can be reduced, which can reduce system costs and better extend the life of the power switching device.

Copyright

© 2026 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Jingxuan Sun
PY  - 2026
DA  - 2026/02/18
TI  - Capacitor Voltage Control and Harmonic Suppression of Modular Multilevel Converter
BT  - Proceedings of the 2025 International Conference on Electronics, Electrical and Grid Technology (ICEEGT 2025)
PB  - Atlantis Press
SP  - 811
EP  - 822
SN  - 2352-5401
UR  - https://doi.org/10.2991/978-94-6463-986-5_83
DO  - 10.2991/978-94-6463-986-5_83
ID  - Sun2026
ER  -