磁偏置超导故障限流器限流响应模型与并网运行研究

针对电网短路故障限流问题,提出一种新型磁偏置超导故障限流器(SFCL),采用超导无感组件、双分裂电抗器支路两级限流的运行方式,具有自触发、分级故障限流、快速自我恢复等优点.应用MATLAB/Simulink软件,搭建了含磁偏置SFCL的10 kV电网线路仿真模型,提出超导限流组件磁热耦合特性的物理建模方法,并对0°和90°短路故障角下的SFCL并网限流效果进行瞬态仿真和比较.仿真结果表明,在电网0°和90°不同故障短路角电流冲击下,SFCL在首半波中的限流率分别为36.45％和45.89％,随后第2个半波的最大限流率达到78.58％,限流电阻在90°短路故障角下的变化率是0°短路故障角下的1.75倍,实现了较快的限流动作响应和显著的分级限流效果.最后实验验证了磁偏置超导限流技术的可行性.

Fault current limiting modeling and grid-connected operation analysis for magneto-biased superconducting fault current limiter

Aiming at the problem of short circuit fault current limiting in power grids, a novel magneto-biased SFCL(Superconducting Fault Current Limiter) with the operation mode of two-stage fault current limiting through non-inductive superconducting unit and double-split reactor branch is proposed, which has the advantages of self-triggering, hierarchical fault current limiting and fast self-recovery. Using MATLAB/Simulink software, a 10 kV power grid simulation model including the magneto-biased SFCL is built. A physical modeling method of the magnetic and thermal coupling characteristics of superconducting current limiting units is proposed, and the transient simulation and comparison of fault current limiting effects are carried out under the conditions of the short circuit fault angles of 0° and 90°. Results show that, the fault current limiting rates of SFCL respectively reach to 36.45% and 45.89% when the short circuit fault angles are 0° and 90° in the first half cycle, and the maximum fault current limiting rate in the second half cycle is 78.58%. Moreover, the rate of change of the quench resistance under the condition of the short circuit fault angle of 90° is 1.75 times as large as that under the condition of the short circuit fault angle of 0°,which realizes the quick current limiting response and significant hierarchical current limiting effect. Experiment verifies the feasibility of the magneto-biased superconducting fault current limiting technology.