针对直流电力系统短路电流分断困难的问题,提出了基于YBa2Cu3O7薄膜的电阻型超导故障限流器(SFCL)保护方案,设计了300V/200A的SFCL模型机。试验分析了不同的电源电压、负载电感和负载电阻等系统参数对薄膜限流效果及失超特性的影响。试验表明,YBa2Cu3O7薄膜能在短路电流到达临界电流Ic后准确动作,并在0.1ms时间里将短路电流峰值限制在2L以内。随着电源电压的增加,薄膜的失超传播速度和失超电阻值迅速增加。推导出限流器重要指标Umax、Imax与线路参数(L、R、Ue)、材料特性(Ic)的数值关系。
For breaking the short- circuit current of DC power system,a protection scheme of resistive SFCL(Superconducting Fault Current Limiter) based on YBa2Cu3O7 thin film is presented and a 300 V/200 A SFCL prototype is designed. The influences of source voltage,load inductance and load resistance on current limit and quench characteristics are tested. The test results show that,YBaECU3O7 film acts exactly when the short-circuit current reaches critical current Ic and limit it below 2Ic within 0.1 ms;the quench propagation velocity and quench resistance increase rapidly along with the increase of source voltage. The numerical relations between the technical data(Umax, Imax) and the line parameters(L,R,Ue) and material characteristics(Ic) are deduced.