| 引用本文: | 尹号,于大川,李梅航,周念成.基于串并联子模块的MMC电容电压纹波抑制策略[J].电力自动化设备,2025,45(12):171-177,244. |
| YIN Hao,YU Dachuan,LI Meihang,ZHOU Niancheng.Capacitor voltage ripple suppression strategy for modular multi level series/parallel converter[J].Electric Power Automation Equipment,2025,45(12):171-177,244. |
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| 摘要: |
| 模块化多电平串并联换流器(MMSPC)子模块长期串联运行导致电容电压波动显著增大，限制了系统性能的提升。针对这一问题，提出一种基于2倍频环流注入的控制策略，用以抑制电容电压波动。针对调制过程中子模块充放电不均的问题，设计周期性开关状态置换方法，以增强能量均衡性。通过桥臂功率分量解析与瞬时功率平衡原理，构建2倍频环流控制器，实现对基频波动分量的动态补偿。在MATLAB/Simulink平台构建并网逆变模型，仿真结果表明，该策略可在保持子模块电容电压纹波幅值不变的情况下，有效降低子模块电容容值30%以上，并显著提升电容电压一致性，从而减少了子模块的体积与成本，提升了系统整体经济性，为深远海上风电的高效并网提供了一种解决方案。 |
| 关键词: 模块化多电平串并联变换器 环流注入 自均压 无电压传感器 纹波抑制 电容电压平衡 |
| DOI：10.16081/j.epae.202510027 |
| 分类号:TM614 |
| 基金项目:山东省自然科学基金资助项目(ZR2025QC1161) |
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| Capacitor voltage ripple suppression strategy for modular multi level series/parallel converter |
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YIN Hao1, YU Dachuan1, LI Meihang1, ZHOU Niancheng2
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1.College of Automation & Electric Engineering, Qingdao University of Science & Technology, Qingdao 266061, China;2.State Key Laboratory of Power Transmission Equipment Technology, School of Electrical Engineering, Chongqing University, Chongqing 400044, China
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| Abstract: |
| The long-term series operation of submodules in the modular multilevel series/parallel converter (MMSPC) leads to a significant increase in the voltage fluctuation of the capacitors, which restricts the improvement of the system performance. To mitigate this issue, a control strategy based on second-harmonic circulating current injection is proposed to suppress capacitor voltage fluctuations. A periodic switching state replacement method is designed to enhance energy balancing and alleviate unequal charging/discharging among submodules. Based on the analysis of bridge-arm power components and the instantaneous power balance principle, a second-harmonic circulating current controller is designed to dynamically compensate for fundamental-frequency fluctuation components. A grid-connected inverter model is developed in MATLAB/Simulink to verify the proposed strategy. Simulative results show that the proposed strategy can reduce the required submodule capacitance by over 30% while maintaining the capacitor voltage ripple amplitude, and significantly improve the consistency of the capacitor voltage. Consequently, the size and cost of submodule are reduced, the overall economy of the system is improved, and providing a solution for the efficient offshore wind power integration. |
| Key words: modular multilevel series/parallel converter circulating current injection self-voltage balancing voltage sensor-free ripple suppression capacitor voltage balancing |
