| 引用本文: | 杨立敏,李耀华,李子欣,王平.MMC子模块故障下能量再平衡控制与安全运行域分析[J].电力自动化设备,2018,(4): |
| YANG Limin,LI Yaohua,LI Zixin,WANG Ping.Energy rebalance control and safe operation region analysis of MMC with sub-module fault[J].Electric Power Automation Equipment,2018,(4): |
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| 摘要: |
| 模块化多电平换流器(MMC )在柔性直流输电领域得到了广泛的应用。在高压大功率场合，MMC的子模块数量庞大，子模块故障是一种常见的故障类型。为了提高可靠性，通常MMC每个桥臂上均设置一定数量的冗余子模块。然而，当MMC发生不对称子模块故障时，直流电流中会出现基频波动，影响MMC的运行性能。针对上、下桥臂同时存在故障子模块的工况，分析了MMC桥臂间能量平衡的条件。据此，提出了一种能量再平衡控制策略，以抑制直流电流中的基频波动。与传统控制策略相比，在额定冗余运行域内，所提控制策略无需提高子模块电容电压。分析了采用所提控制策略时MMC的最大安全运行域，结果表明所提控制策略能扩展MMC的安全运行域，进一步提高其可靠性。±350 kV月1000 M W的MMC硬件在环实验结果验证了所提能量再平衡控制策略的有效性以及安全运行域分析的正确性。 |
| 关键词: 模块化多电平换流器 子模块故障 能量再平衡 安全运行域 |
| DOI：10.16081/j.issn.1006-6047.2018.04.008 |
| 分类号:TM46;TM761 |
| 基金项目:国家高技术研究发展计划(863计划)资助项目(2015 AA050102) |
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| Energy rebalance control and safe operation region analysis of MMC with sub-module fault |
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YANG Limin1,2, LI Yaohua1,2, LI Zixin1,2, WANG Ping1
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1.Key Laboratory of Power Electronics and Electric Drive, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China;2.School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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| Abstract: |
| MMC(Modular Multilevel Converter) has been widely applied in the flexible-HVDC power transmission and the sub-module fault is its common fault type due to the huge quantity of sub-modules in the high-voltage and large power MMC. A certain amount of redundant sub-modules are set in each bridge-arm of MMC to improve its re-liability. However, when asymmetric sub-module fault occurs in MMC, the fundamental fluctuations will appear in the DC current, influencing the operation performance of MMC. The conditions for energy balance among bridge-arms of MMC are analyzed under the working condition of failure submodules both in upper and lower bridge-arms, on this basis, an energy rebalance control strategy is proposed to suppress the fluctuations in DC current, which, compared with the traditional control strategy, needs not to increase the capacitor voltage of sub-module in the rated redundant operation region. The maximum safe operation region of MMC by using the proposed control strategy is also analyzed, and it is proved to be extended and the reliability of MMC is further improved. Hardware in loop experiment results of 1350 kV/1000 MW MMC verify the effectiveness of the proposed control strategy and the validity of safe operation region analysis. |
| Key words: modular multilevel converter sub-module fault energy rebalance safe operation region |
