适用于直流配电网的组合电容型直流负荷开关

Assembly DC load switch based on pre-charged capacitors suitable for DC distribution network

直流负荷开关是构建直流配电网的关键设备。针对现有直流负荷开关附加设备多、体积大、控制复杂等缺点,文中提出组合电容型直流负荷开关拓扑,并分析所提拓扑工作原理、控制策略和参数设计。该负荷开关利用预充电电容构成源侧部分和荷侧部分。且多条直流母线出线上的负荷开关共用源侧部分,降低了设备体积和成本。切负荷过程中,通过源、荷侧电容的配合,给机械开关提供一个低电压、零电流的关断条件。最后在Matlab/Simulink中搭建仿真模型,对所提拓扑的可行性与有效性进行验证。结果表明,文中直流负荷开关能够可靠无弧关断负荷电流,保障直流配电网的安全运行,且所需设备成本低,有助于提高直流配电网的经济性。

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.