基于分裂电抗器的开关转换型超导直流限流器

Research on switching-conversion DC SFCL based on a split reactor

多端柔性直流电网技术的发展面临快速限制短路电流的巨大挑战。超导直流限流器被认为是故障限流的最有效解决方案之一。提出了一种基于分裂电抗器的开关转换型超导直流限流器,该限流器通过限流单元(分裂电抗器的绕组由YBCO带材绕制)与固态开关相配合,稳态时,限流器呈并联结构,等效电感小,运行损耗低;故障发生后,限流器转换为串联结构,并受大电流冲击而失超,产生较大的限流电阻,能够有效限制短路电流。基于MATLAB/Simulink建立了超导限流器模型,仿真分析了限流过程中的电流变化情况,对比分析了开关动作前后的限流情况,验证了该限流器的可行性。

With the fast development of voltage source converter based high voltage direct current(VSC-HVDC)power system,an effective fault current method is in demand.Superconducting fault current limiter(SFCL)is considered to be one of the most effective solutions for DC fault current limiting.In this paper,a switching-conversion DC SFCL based on a split reactor was presented.The FCL was combined the solid switches with the current limiting units(the coils of the split reactors were wound by YBCO tape).On steady state,the FCL was in parallel structure with small equivalent inductance and low operating loss.Once the fault occured,it was converted into a series structure,and the superconducting coil was quenched,resulting in a large current limiting impedance,which could effectively limit the short-circuit current.The SFCL model was built on MATLAB/Simulink.The current variation in the current limiting process was simulated and analyzed.The current limiting characteristics were analyzed comparatively before and after the solid switches action.The feasibility of the SFCL was verified.