中文摘要：

基于柔性直流的配电系统因便于新能源接入等优势成为了国内外研究热点,其中设备暂态电流特性是设备选型的重要依据。针对基于柔性直流的±10 k V配电系统关键设备的暂态电流特性,开展了理论分析、仿真计算和限流措施研究。首先基于系统的拓扑结构,分析并确定了各区域关键设备及其暂态电流决定性故障工况。在此基础上,采用理论分析和仿真建模计算相结合的手段开展了暂态电流的研究,通过仿真对比了不同阻抗限流电抗器的限流效果,考虑保护时间需求和断路器开断能力的要求,结合经济性、占地面积等因素确定了限制接入设备暂态电流的电抗大小。最后,理论计算和仿真分析了各区域关键设备暂态电流水平。计算结果表明,主换流器桥臂及子模块的暂态电流峰值为9.72 k A,线路上接入的两电平换流器暂态电流峰值接近6 k A,直流变压器直流母线暂态电流峰值接近7 k A。研究结果为±10 k V基于柔性直流的智能配电系统关键设备的选型提供了参考。

英文摘要：

Flexible DC power distribution system has become a hot research topic for its advantages such as new energy accessible, etc. Transient current of equipment is the basis of equipment selecting and designing. Theoretical analysis and simulating calculation as well as current limiting measures researches were made to study the transient current＇s charac- teristics of key equipment in a ±10 kV flexible DC power distribution system. Firstly, we analyzed the topological structure of the system, determining the key equipment and their corresponding decisive fault types. Then, we theoretically analyzed,simulated and calculated the transient current. Through simulation, we compared the current limiting effects of different current limiting reactive resistances. Considering the response time of protection, the breaking capacity of DC breaker and economic efficiency as well as spaces, we determined the suitable current limiting reactive resistance series connected in buses of plug-in devices. Finally, we evaluated the transient current level of key equipment. The results show that the transient current level of bridge inductance and sub-modules of main converter is 9.72 kA. The transient current level of two-level VSC converters switched in the line is about 6 kA, and the bus of DC-DC transformers is about 7 kA. The conclusions can be a reference and guidance when designing and selecting key equipment for flexible DC power distribution system.