The high-voltage direct current (HVDC) circuit breaker is becoming popular with the rapid development of the flexible HVDC grid for efficient DC fault ride-through purposes. This paper proposes a novel module for reciprocating HVDC circuit breaker topology, whose branch connections are able to switch between series and parallel modes to limit the rising rate and interrupt the DC fault currents. Diode-bridge sub-modules (DBSMs) are used to compose the main branch for current interruption. Besides fault clearance, the proposed topology has the advantageous function of DC fault current limiting by employing DBSMs with bi-directional conduction capability. The topology can easily switch among branch connection modes through the assembled trans-valves, and their resistance and reactance are very small in the normal state when branches are in parallel and the values become promptly large in the transient state when the branches are series connected. With the modular design, it is easy to change the number of branches or sub-modules and the types of sub-modules to adapt to more specific needs. A 6-terminal modular multi-level converter (MMC) based HVDC grid is established in PSCAD/EMTDC, and various simulation scenarios are carried out to validate the proposed topology.

中文翻译：

---

具有限流和双向串并联分支开关功能的模块化往复式HVDC断路器

高压直流（HVDC）断路器随着灵活的HVDC电网的快速发展而变得流行，以实现有效的直流故障穿越目的。本文提出了一种用于往复式HVDC断路器拓扑的新型模块，其支路连接能够在串联和并联模式之间切换，以限制上升速率并中断DC故障电流。二极管桥子模块（DBSM）用于构成电流中断的主要分支。除了清除故障外，通过采用具有双向传导能力的DBSM，所提出的拓扑还具有限制直流故障电流的有利功能。通过组装的跨阀，拓扑可以轻松在分支连接模式之间切换，当分支并联时，它们的电阻和电抗在正常状态下很小，而在分支串联连接时，它们在瞬态下的值迅速变大。通过模块化设计，可以轻松更改分支或子模块的数量以及子模块的类型，以适应更具体的需求。在PSCAD / EMTDC中建立了一个基于6端子模块化多电平转换器（MMC）的HVDC电网，并进行了各种仿真方案以验证所提出的拓扑。