Non-Ideal Proportional Resonant Control for Modular Multilevel Converters Under Sub-Module Fault Conditions
Non-Ideal Proportional Resonant Control for Modular Multilevel Converters Under Sub-Module Fault Conditions
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DOI：
10.1109/tec.2019.2938395
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发表时间：
2019-08
影响因子：
4.9
通讯作者：
Pengfei Hu;Zhengxu He;Shuqi Li;J. Guerrero
中科院分区：
文献类型：
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作者：
Pengfei Hu;Zhengxu He;Shuqi Li;J. Guerrero
模块化多电平转换器 (MMC) 已成为高电压和高功率应用最有前途的拓扑。子模块（SM）故障穿越能力是MMC最重要的特性之一。为了研究控制SM故障的方法，分析了冗余SM的热备份和冷备份配置的差异。然后，对MMC的内部不对称动态模型进行了分析，结果表明环流中的非预期基波和三次谐波分量导致了直流电流的波动。基于该模型，结合传统环流抑制方法和SM容错方法，提出并分析了非理想比例谐振（PR）控制器。该控制方案可以在不知道故障SM的数量和额外通信系统的情况下抑制SM故障下MMC直流电流的波动。其有效性通过 PSCAD/EMTDC 模拟和按比例缩小的原型实验得到验证。
The Modular Multilevel Converter (MMC) has become the most promising topology for high-voltage and high-power applications. Sub-Module (SM) fault ride-through capability is one of the most important features of the MMC. To study the approach of controlling SM faults, the differences between hot-backup and cold-backup configuration of redundant SMs are analyzed. After that, an internal asymmetrical dynamic model for the MMC is analyzed, which shows that unexpected fundamental and 3rd harmonic components in the circulating current result in fluctuation of DC current. Based on this model and by integrating the conventional circulating current suppression method and the SM-fault tolerant approach, a non-ideal proportional-resonant (PR) controller is proposed and analyzed. This control scheme can suppress the fluctuation of the DC current of the MMC under SM faults without the knowledge of the number of faulty SMs and extra communication system. Its effectiveness is verified by both PSCAD/EMTDC simulations and scaled-down prototype experiments.