Analysis and Experimental Research on a Novel Multi-Contact MVDC Natural Current Commutation Breaking Topology
Analysis and Experimental Research on a Novel Multi-Contact MVDC Natural Current Commutation Breaking Topology
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DOI：
10.1109/access.2020.3030660
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发表时间：
2020
期刊：
影响因子：
3.9
通讯作者：
Bowen Jia;Jianwen Wu;Shangwen Xia;Xiaowu Luo;Suliang Ma;Yuanchun Jiang
中科院分区：
文献类型：
--
作者：
Bowen Jia;Jianwen Wu;Shangwen Xia;Xiaowu Luo;Suliang Ma;Yuanchun Jiang
高性能的中压直流（MVDC）电源系统是许多工业应用的先决条件。为满足航空、航天、新能源等领域对高压直流开断的要求，提出了一种负载分支和燃弧分支并联的MVDC换相开断拓扑。与基于半导体器件的传统结构相比，所提出的拓扑中的每个分支包含机械接触，这提供了更低的通态损耗和更高的分压能力。此外，理论分析和实验结果验证了载流器的异步运行，并证实了电弧分支可以实现电流的自然换向，用于开断过载电流或短路电流。结合微电接触理论和电极材料的相变特性，建立了详细的等效模型，研究了换向过程中接触区的熔桥和伪电弧现象。结果表明，虽然存在熔融金属桥和伪电弧增加了电流换向时间和电极材料的侵蚀，但换向过程可以进行。最后，基于额定条件下电极材料的软化电压，除了动态换流时的相变外，还可以适当调整粗糙度$\sigma $和弹性模量$E$，实现无电弧换流。
The high performance of medium-voltage direct current (MVDC) power supply system is a pre-requisite for several industrial applications. To meet the higher voltage direct current (DC) breaking requirements in the fields of aviation, aerospace, and new energy, this article proposes a novel MVDC commutation breaking topology that combines a load-carrying branch and an arcing branch in parallel. In contrast to the conventional structure based on semiconductor devices, each branch in the proposed topology contains a mechanical contact, which provides a lower on-state loss and higher voltage-breaking capacity. Moreover, the theoretical analysis and experimental results verified the asynchronous operation of the current-loading and confirmed that the arcing branch can realize the natural commutation of the current for the breaking of overload current or short-circuit current. A detailed equivalent model that combines the micro-electrical contact theory and phase-change characteristics of the electrode material was then established to investigate the molten metal bridge and pseudo arc phenomenon of the contact area during the commutation process. The results indicated that although the presence of a molten metal bridge and pseudo arc increase the current commutation time and erosion of the electrode material, the commutation process can be conducted. Finally, based on the softening voltage of the electrode material under the rated conditions, in addition to the phase change during dynamic commutation, the roughness $\sigma $ and elastic modulus $E$ can be adjusted appropriately to achieve arc-less current commutation.