A Hybrid Modular Multilevel Converter Family With Higher Power Density and Efficiency
A Hybrid Modular Multilevel Converter Family With Higher Power Density and Efficiency
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DOI：
10.1109/tpel.2021.3055690
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发表时间：
2021-08
影响因子：
6.7
通讯作者：
Jian Liu;D. Dong;Di Zhang
中科院分区：
文献类型：
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作者：
Jian Liu;D. Dong;Di Zhang
模块化多电平变换器（MMC）具有可扩展性、可靠性和易于实现等诸多优点，但存在大量开关器件和电容器的问题。为了提高中压应用的功率密度和效率，本文通过有源中性点钳位转换器和链节臂的组合推出了混合模块化多电平转换器 (HMMC) 系列。与传统MMC相比，HMMC系列的三种拓扑结构可以有效地将链节电压降低一半。提出单相和三相操作原理以强调这一重要特征。在三种不同的中压电平下，对传统 MMC 和 HMMC 拓扑之间的几个关键指标（例如元件数量、电容器尺寸和半导体损耗）进行了比较。结果表明，与传统 MMC 相比，HMMC 系列的最佳拓扑可节省约 30% 的器件、50% 的总电容器和 32% 的功率损耗。还提到了一种简单的单相控制方法来平衡电容器电压。最后搭建了单相HMMC实验样机来验证三种拓扑的有效性。
Modular multilevel converter (MMC) has many advantages of scalability, reliability and easy implementation, but suffers from large number of switching devices and capacitors. To improve the power density and efficiency for medium voltage applications, this article introduces a hybrid modular multilevel converter (HMMC) family through the combination of active neutral-point-clamped converter and chain-link arm. Three topologies in HMMC family can effectively reduce chain-link voltage by half compared with traditional MMC. Single- and three-phase operation principles are presented to highlight this important features. Several critical metrics, such as component number, capacitor sizes, and semiconductor losses, are compared between the conventional MMC and HMMC topologies at three different medium voltage levels. The result indicates the best topology from the HMMC family can save around 30% devices, 50% total capacitor and 32% power losses compared with traditional MMC. A simple single-phase control method is also mentioned to balance capacitor voltage. Finally, a single-phase HMMC experimental prototype is built to verify the effectiveness of three topologies.