中文摘要：

提出了一种由直流后备式熔断器和直流真空负荷开关串联组成的直流组合电器，对其直流开断特性进行了仿真和实验研究。新型直流组合电器可完成直流电流的全范围开断：当开断额定电流和过载电流时．采用真空直流负荷开关利用人工电流过零法开断电流，此时后备式熔断器不动作；当开断大过载电流和短路电流时，采用后备式直流熔断器直接开断大电流，也可以将大电流限制至较低幅值再采用真空直流负荷开关进行分断。实验结果证明，该直流真空负荷开关可以在5 ms内成功开断200 A至1．7 kA的直流电流，直流后备式熔断器可以开断1．7 kA及以上的直流电流。

英文摘要：

The objective of this paper is to propose a DC combinations composed of a DC vacuum switch and aDC back-up fuse in series. The DC interruption characteristics of the proposed combinations are simulatedand experimentally investigated. The DC combinations is able for a full-range DC current interruption. The vacuumswitch is responsible for load current and over-load current interruption based on an artificial current zerotechnology. The back-up fuse is responsible for short-circuit current interruption. The fault current can beinterrupted by the back-up fuse directly or first the fault current be limited to a low level by the fuse, then thevacuum switch is used. Experimental results show that the DC vacuum switch can interrupted a DC current from200 A to 1.7 kA in 5 ms, the back-up fuse can interrupted 1.7 kA and above.