Impedance Variation of a Flux-Lock Type SFCL Dependent on Winding Direction Between Coil 1 and Coil 2

Comparative study on current limiting characteristics of flux-lock type SFCL with series or parallel connection of two coils

“…From the above analysis, in case of the SFCL with parallel connection of two coils, the limited line current can be confirmed to be more decreased with the additive polarity winding, which agrees with the analysis results of Eq. (3) and the previous our reports [10][11]. The voltage of HTSC element in case of the subtractive polarity winding as seen in Fig.…”

“…5b). Therefore, it is expected that the voltage burden of HTSC element during a fault period also in case of the additive polarity winding can be more reduced compared to that of the subtractive polarity winding as well [10][11]. Figs.…”

“…Among the SFCLs, the flux-lock type SFCL with parallel connection of two coils, which was first suggested by Matsumura [8], was reported to increase or decrease the operational current level and the limiting impedance of the SFCL by adjusting the winding direction of two coils and the inductance ratio between two coils [9][10][11]. Recently, we have also proposed the flux-lock type SFCL with series connection of two coils and reported that its fault current limiting operation had the same operational principle as the previous flux-lock type SFCL with parallel connection of two coils [12,13].…”

Elimination of chaotic ferroresonance in power transformer by ISFCL

“…Among several types of SFCLs, like for example normal resistive [42,43], flux flow resistive [48], inductive [49], flux-lock [50,51] and saturated core [52,45], inductive type SFCL (ISFCL) has some superior properties like: automatic detection of fault current, flexibility in turn ratio, grandiosity of impedance in fault duration, isolation of device and power system from view point of current flowing, very low resistance and consequently low heat loss and finally self-recovering [45,[53][54][55].…”

Analysis on Current Limiting Characteristics According to the Influence of the Magnetic Flux for SFCL with Two Magnetic Paths

“…However, when a fault occurs, the resistance from the quenching of the high-T c superconducting (HTSC) element generates the induced voltage through which the fault current is limited. Thus, it has a characteristic of being able to adjust the limit impedance and operational current through which the fault current is limited by adjusting the inductance ratio and the direction of the two coils of the magnetic flux-lock type SFCL [6][7][8]. On the other hand, the fault current that is greatly increased while the fault occurs may cause saturation of the core because of the increased magnetic flux inside the core, which would reduce the fault current limiting effects of the SFCL.…”