考虑短路电流非周期分量影响的磁偏置型超导故障限流器设计方法及其限流特性分析

Designing and Current Limiting Characteristics of Magneto-biased Superconducting Fault Current Limiter Considering DC Component of Short-circuit Current

随着电力负荷快速增长,电力系统的故障电流水平持续上升,甚至超出了现有断路器的开断能力;为有效限制故障电流,超导故障限流器(superconducting fault current limiter,SFCL)逐渐投入应用。SFCL在正常运行时呈现零阻抗,故障发生后迅速转为高阻抗,可作为配合断路器开断的理想选择,提高电力系统的运行安全性。介绍了一种磁偏置型超导故障限流器(magneto-biased superconducting fault current limiter,MBSFCL),提出了考虑短路电流非周期分量影响的MBSFCL设计方法,对于MBSFCL的制造具有一定的指导意义。通过搭建仿真模型,验证了所提出方法的可行性,并对MBSFCL的限流特性进行了深入分析,讨论了不同非周期分量对断路器的开断影响,以及MBSFCL中电感、电阻参数变化对短路电流及其分量的限流效果影响。分析结果表明,在所提出MBSFCL设计方法中必须考虑非周期分量,且MBSFCL的电阻参数变化对短路电流的抑制效果更为显著。

The rapid growth of power loads makes the fault current levels in the power system continue to rise,even exceeds the interrupting capacity of the existing circuit breakers.To effectively limit the fault current,the Superconducting Fault Current Limiters(SFCLs) are gradually being put into practice.The SFCL presents zero impedance during the normal operation but rapidly turns to high impedance when a fault occurs.This characteristic can be as an ideal choice to be used along with the circuit breakers to improve the operational safety of the power systems.By introducing a magneto-biased superconducting fault current limiter(MBSFCL),this paper proposes a design method of the MBSFCL considering the DC component of short-circuit current,which may have a certain guiding significance for the manufacture of an MBSFCL.The feasibility of the proposed method is verified by building a simulation model,and the current-limiting characteristics of the MBSFCL are analyzed in depth.The effects of different DC components on the interrupting of the circuit breaker,and the effects of the current-limiting effects of the variations of L or R parameters in the MBSFCL on the short-circuit current and its components are discussed.The analytical results show that the DC component must be considered in the proposed MBSFCL design method and that the variation of the R parameter of the MBSFCL has a more significant effect on the short-circuit current suppression.