Abstract:The direct current (DC) load switch is the key equipment for constructing the DC distribution network. Aiming at the shortcomings of the existing DC load switch,such as much additional equipment,large size and complex control,an assembly DC load switch topology based on pre-charged capacitors is proposed. The working principle,control strategy and parameter design of the proposed topology are analyzed. The load switch utilizes pre-charged capacitors to form a source side part and a load side part. The load switches on the outgoing lines of multiple DC buses share the source side part,which reduces the size and cost of the equipment. In the process of load shedding,through the cooperation of source and load side capacitors,a low voltage and zero current breaking condition is provided for the mechanical switch. Finally,a simulation model is built in Matlab/Simulink to verify the feasibility and effectiveness of the proposed topology. The results show that the proposed DC load switch can reliably turn off the load current without arc which ensures the safe operation of DC distribution network. The cost of equipment required is low,which improves the economic efficiency of DC distribution network.