一种基于电容主动钳位式混合式直流断路器  

A Capacitor-based Active Clamp Type Hybrid DC Circuit Breaker

作　　者：范兴明[1] 李涛 张思舜 许洪华 张鑫[1] FAN Xingming;LI Tao;ZHANG Sishun;XU Honghua;ZHANG Xin(School of Mechanical and Electrical Engineering,Guilin University of Electronic and Technology,Guilin 541004,Guangxi Zhuang Autonomous Region,China)

机构地区：[1]桂林电子科技大学机电工程学院,广西壮族自治区桂林市541004

出　　处：《电网技术》2024年第11期4620-4627,I0050,I0049,共10页Power System Technology

基　　金：国家自然科学基金项目(61741126);广西自然科学基金(2022GXNSFAA035533)。

摘　　要：混合式直流断路器兼具机械式直流断路器的静态特性与固态直流断路器的动态特性,具有较快的开断速度和较低的通态损耗,是应用于中高压直流输配电系统的优选技术方案。然而,基于模块级联的混合式直流断路器存在投资成本较高、避雷器吸能较高、不具备故障性质判别能力等问题,限制了断路器的工程化应用。该文在现有结构的基础上进行一定的改进,提出一种基于电容主动钳位式混合式直流断路器。主要利用电容电压钳位换流站侧电压,避免了换流站电压迅速跌落的同时降低了换流站侧的故障电流峰值。此外,电容电压还可作为线路故障和重合闸时的辅助判据。针对所提结构进行了详细的理论推导和分析,在PSCAD/EMTDC中建立四端直流环网对所提结构进行验证,并与原有方案进行对比。仿真结果证明所提结构可行且相对原有方案具备一定优势。A hybrid DC circuit breaker has both the static characteristics of the mechanical DC circuit breaker and the dynamic characteristics of the solid-state DC circuit breaker.It has a faster breaking speed and lower on-state loss.It is the preferred technical solution for medium and high-voltage DC transmission and distribution systems.However,the hybrid DC circuit breaker based on module cascade has problems such as high investment cost,high energy absorption of arresters,and lack of ability to distinguish the nature of faults,which limits the engineering application of circuit breakers.Based on the existing structure,this paper proposes a hybrid DC circuit breaker based on capacitor clamping.The pre-charged capacitor is mainly used to clamp the voltage of the converter station side,which avoids the rapid drop of the voltage of the converter station and reduces the peak value of the fault current on the converter station side.In addition,the capacitor voltage can also be used as an auxiliary judgment for line fault and reclosing.The detailed theoretical derivation and analysis of the proposed structure are carried out.The single-ended equivalent and four-terminal DC loop network,is established in PSCAD/EMTDC to verify the proposed structure and compared with the original scheme.The simulation results show that the proposed structure is feasible and has advantages over the original scheme.

关 键 词：混合式直流断路器 故障性质判别 电容钳位 辅助判据 

分 类 号：TM721[电气工程—电力系统及自动化]