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ORIGINAL RESEARCH article

Front. Electron.
Sec. Power Electronics
Volume 5 - 2024 | doi: 10.3389/felec.2024.1475338
This article is part of the Research Topic Enhancing Power Electronic Converters for Modern Power Systems View all 3 articles

Flexible Switching Method of Control Strategy for MMC-HVDC Converter based on AC Power Grid Strength

Provisionally accepted
Maolan Peng Maolan Peng 1*Lei Feng Lei Feng 1*Xiaoyu Hao Xiaoyu Hao 2*Meihui Sun Meihui Sun 2*Wen Jiang Wen Jiang 2Chunyi Guo Chunyi Guo 2*
  • 1 China Southern Power Grid (China), Guangzhou, Guangdong Province, China
  • 2 North China Electric Power University, Beijing, China

The final, formatted version of the article will be published soon.

    Modular Multilevel Converter based High Voltage Direct Current (MMC-HVDC) has been widely used in the large-scale transmission of renewable energy sources (RESs). However, the operating conditions of MMC-HVDC system with RESs are complex and variable, making it challenging to apply a single converter control strategy to different operating conditions, which affects the safe and stable operation of the whole system. In this paper, a flexible switching method of control strategies is proposed for MMC-HVDC converter. Firstly, the state-space model of MMC-HVDC under different control strategies is established, and the small signal stability and stable operation ranges under these control strategies are analyzed. Then, according to the proposed control strategy switching principle, a flexible control switching method for MMC-HVDC converter is proposed. This flexible control switching method ensures a smooth switching between different control strategies and causes a minimal disturbance to the overall system. Finally, a simulation model is established on the PSCAD/EMTDC platform, and the feasibility of the flexible control switching strategy for the MMC-HVDC system is verified. The simulation results show that very small disturbance is observed during the control switching and the flexible control switching strategy can effectively maintain the stable operation of MMC-HVDC system under different operating conditions.

    Keywords: modular multilevel converter (MMC), Renewable Energy Sources, Small signal stability, flexible control switching, P-q control strategy, P-V control strategy

    Received: 03 Aug 2024; Accepted: 13 Dec 2024.

    Copyright: © 2024 Peng, Feng, Hao, Sun, Jiang and Guo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Maolan Peng, China Southern Power Grid (China), Guangzhou, Guangdong Province, China
    Lei Feng, China Southern Power Grid (China), Guangzhou, Guangdong Province, China
    Xiaoyu Hao, North China Electric Power University, Beijing, China
    Meihui Sun, North China Electric Power University, Beijing, China
    Chunyi Guo, North China Electric Power University, Beijing, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.