An Improved Circulating Current Injection Method for Modular Multilevel Converters in Variable-Speed Drives
An Improved Circulating Current Injection Method for Modular Multilevel Converters in Variable-Speed Drives
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DOI：
10.1109/tie.2016.2547899
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发表时间：
2016-03
影响因子：
7.7
通讯作者：
Binbin Li;Shaoze Zhou;Dandan Xu;Rongfeng Yang;Dianguo Xu;C. Buccella;Carlo Cecati
中科院分区：
文献类型：
--
作者：
Binbin Li;Shaoze Zhou;Dandan Xu;Rongfeng Yang;Dianguo Xu;C. Buccella;Carlo Cecati
模块化多电平转换器 (MMC) 代表了中压电机驱动应用中一种有趣的新兴拓扑。在变速驱动器中使用这种拓扑的主要挑战是低速恒扭矩时子模块电容器的电压纹波较大。本文提出了一种改进的环流注入方法，该方法并没有完全消除电容器电压纹波，而是将其保持在合理的值范围内。因此，注入循环电流的幅度减小，从而提高转换器效率并降低半导体额定电流。还讨论了子模块电容的尺寸，这是设计变速驱动器中的 MMC 时的一个重要考虑因素。所提出的方法已通过仿真和实验结果成功得到验证。
Modular multilevel converters (MMC) represent an interesting and emerging topology in medium-voltage motor drive applications. The main challenge of using such a topology in variable-speed drives is the large voltage ripple of submodule capacitors at low speed with constant torque. In this paper, an improved circulating current injection method is proposed, which does not completely eliminate the capacitor voltage ripple, but maintains it bounded within reasonable values. As a result, magnitude of injected circulating current is reduced, leading to converter efficiency improvement and reduction of semiconductor current ratings. Dimensioning of submodule capacitance is also discussed, which is an important consideration when designing the MMCs in variable-speed drives. The proposed method has been successfully validated by simulation and experimental results.