Hybrid dc circuit breakers (HCBs) are vital equipment in dc grid systems. However, HCBs are usually costly since massive full-controlled power semiconductors are required to withstand high surge voltage and current stresses during current interrupting. Thyristors are good alternatives in realizing HCBs in view of their low cost and high current carrying capability; however, turning off the thyristor fast and reliably is a challenging task. In this article, a novel HCB topology is proposed, of which the solid-state part is realized by hybrid connection of thyristors and insulated gate bipolar transistor (IGBT) half-bridge submodules. The use of IGBT half-bridges provides a negative voltage across the thyristors to turn them off; accordingly, thyristors withstand a major of turn-off surge voltage instead of IGBTs. By this means, a low-cost HCB can be established while maintaining a high breaking speed. Besides, fast reclose and rebreak function is provided by the proposed topology. Operation principle and design consideration of the novel HCB topology are analyzed in detail, and the effectiveness of the proposed HCB is verified by both software simulation and downscaled experimental results.

中文翻译：

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基于晶闸管与IGBT半桥子模块串联的新型混合直流断路器

混合直流断路器 (HCB) 是直流电网系统中的重要设备。然而，HCB 通常很昂贵，因为需要大量的全控制功率半导体来承受电流中断期间的高浪涌电压和电流应力。鉴于其低成本和高载流能力，晶闸管是实现 HCB 的良好替代品；然而，快速可靠地关闭晶闸管是一项具有挑战性的任务。在本文中，提出了一种新型 HCB 拓扑，其中固态部分通过晶闸管和绝缘栅双极晶体管 (IGBT) 半桥子模块的混合连接实现。IGBT 半桥的使用在晶闸管两端提供负电压以关闭它们；因此，晶闸管可以承受较大的关断浪涌电压，而不是IGBT。通过这种方式，可以在保持高分断速度的同时建立低成本的 HCB。此外，所提出的拓扑提供了快速重合和重断功能。详细分析了新型 HCB 拓扑的工作原理和设计考虑，并通过软件仿真和缩小的实验结果验证了所提出的 HCB 的有效性。