Analysis of 3-Phase Superconducting Fault Current Limiters in Power Systems With Inhomogeneous Quenching

The limitation behavior of a 3-phase superconducting fault current limiter (SFCL) in power systems is greatly affected by inhomogeneous quenching among phases, where it can lead to increasing current limitation burden upon some phase units. Accordingly, this paper aims to analyze the behavior of SFCL with inhomogeneous quenching among phases. A model is developed for the resistive type SFCL using PSCAD/EMTDC software considering the transition from superconducting state to normal conducting state through flux flow state. Inhomogeneous quenching is represented in two different ways, either as an inhomogeneity in Ic value or an inhomogeneity in n value. Different types of faults including symmetrical and unsymmetrical faults are studied. For each case, the influence of inhomogeneous quenching on current limitation and corresponding voltage drop across units is evaluated. From the obtained results, it is found that the most severe case appears for line-to-line fault. Therefore, the effect of inhomogeneity degree is discussed for this fault type.