  Short circuit fault currents are increasing due to growing demand for
electricity and high complexity in power systems. Because the fault currents
reach the highest value which the breakers are unable to restrict, the
electrical grid security is under jeopardy. By entering a limiting impedance
into a transmission line in series, these impedances restrict the rising
amounts of fault currents to levels that are acceptable. Saturated core fault
current limiters (SCFCLs) are a pivotal tool for limiting fault currents rise
in power networks that have good performance characteristics. In a normal
condition, these limiters have slight effects on the system and can effectively
limit short circuit currents when occur. In this chapter, various structures of
SCFCLs with different arrangements of ac windings & dc windings are presented
and the currents passing through the FCLs under the normal and faulty system
conditions are assessed and compared. The flux density in various regions of
the core in different arrangements has been investigated as well and the
desired analyzes have been performed. Simulation will be presented based on
COMSOL Multiphysics 5.4, a finite element software package which can provide a
precious assessment to compare these protective devices with different
configurations.
