磁偏置超导限流器在10 kV城市电网中运行参数设计与分析

Operating parameter design and analysis of magneto-biased superconducting fault current limiter in 10 kV typical urban power grid

超导限流器可以用于限制城市电网中日益增大的短路故障电流,成为当前国际上研究热点之一。提出一种阻感混合式新型磁偏置高温超导限流器的拓扑结构,基于MATLAB/SIMULINK软件,建立了磁偏置超导限流器的磁热耦合仿真模型,搭建了含超导限流器的10 kV典型城市电网仿真平台。在该平台上,仿真分析了不同故障类型下的城市电网限流过程,获得故障限流率变化曲线。结果表明,超导限流器失超电阻会影响故障电流首个波峰的限流率,但不影响第二波峰限流率,双分裂电抗器的支路电抗同时影响前两个波峰的限流率;故障电流限流率随超导限流器失超电阻和双分裂电抗器支路阻抗的增大而增大,但增长速率会不断减小。对应最大限流率时,磁偏置超导限流器失超电阻参考值为3.19 Ohm,双分裂电抗器的支路电抗参考值为4.995 Ohm。在该运行参数下,电网故障电流首个波峰限流率达到48%,第二个波峰限流率达到76%,实现了良好的限流效果,验证了设计方法的有效性。

Superconducting fault current limiter(SFCL)can limit the increasing short circuit fault current in urban power grid as one of the international research hotspots.This paper focused on a novel hybrid magneto-biased SFCL and established magneto-thermal coupling model of the magneto-biased SFCL and a typical 10 kV urban power grid simulation platform model on MATLAB/SIMULINK.Running simulation on this platform,we analyzed fault current limiting process under different short-circuit faults and drew curves of fault current limiting rate.It is found that YBCO quench resistance only influences the fault current limiting rate at the first current peak but the single branch reactance of the double-split reactor influences those at the second peak.The current limiting rate increases with these two parameters but the growth rate is decreasing.For a cost-efficient current limiting rate,the reference value of the YBCO quench resistance is 3.19 Ohm and that of the single branch reactance of double-split reactor is 4.995 Ohm.Therefore,the SFCL has a cost-efficient current limiting effect with the current limiting rate of 48%at the first current peak and 76%at the second current peak on this 10 kV urban power grid platform.The result verifies the effectiveness of the design.