【目的】随着直流电网传输容量的提升，基于全控型电力电子器件的混合式直流断路器普遍存在故障电流上升速度快、幅值大、开断困难以及造价昂贵等问题。针对上述问题，提出了一种耦合电感辅助限流的混合式直流断路器拓扑。【方法】该拓扑主支路的耦合电感一次侧对故障电流进行一次限流，限流支路实现对故障电流的二次限流，充分有效地降低了故障电流上升率；主支路的耦合电感二次侧对自充电电容进行预充电，降低设备复杂度；采用晶闸管代替传统IGBT和并联电容实现避雷器的投切，提高了经济性。【结果】对所提拓扑的工作原理和各个主回路参数进行了分析和设计，通过PSCAD/EMTDC建立了四端直流输电网系统模型，将该拓扑与已有典型拓扑进行了对比仿真分析，在发生短路故障时，所提拓扑对故障电流的限流峰值进一步降低，开断时间进一步缩短，避雷器的吸能进一步减少，且有一定的经济性。【结论】所提拓扑具有良好的开断性能，且有一定的经济性，可为后续高压直流断路器在直流输电网系统中的应用提供一定的理论基础。

[Objective] With the increase in transmission capacity of DC grids， issues such as rapid rise of fault current， high amplitude， difficulty in breaking， and high cost arise in hybrid DC circuit breakers based on fully controlled power electronic devices. To address these issues， this paper proposes a hybrid DC circuit breaker topology with coupled inductors for current limiting. [Methods] In the proposed topology， the primary side of the coupled inductors in the main branch limits the fault current for the first time， and the current-limiting branch limits the fault current for the second time， thereby effectively reducing the fault current rise rate. The secondary side of the coupled inductors in the main branch pre-charges the self-charging capacitor； this remarkably reduces the equipment complexity. Traditional IGBTs and parallel capacitors are replaced by thyristors to switch surge arresters， improving the economy. [Results] The working principle and parameters of each main circuit in the proposed topology were analyzed. On this basis， a four-terminal DC transmission grid system model was established in PSCAD/EMTDC. The proposed topology was then compared with existing topologies via simulations. When a short-circuit fault occurs， the proposed topology further reduces the peak value of the fault-current limit， shortens the breaking time， reduces the energy absorption of the surge arrester， and provides economic benefits. [Conclusions] The analysis shows that the proposed topology affords good breaking performance and certain economic benefits. These findings can provide a theoretical basis for the future application of high-voltage DC circuit breakers in DC transmission grid systems.