抄録
In this paper, we theoretically compared the fundamental characteristics of fault current limiter (FCL) with high Tc superconductor (HTS) and two coaxial air core coils based on steady state analysis. Two types of FCL are possible. One of them is parallel type and the other one is transformer type. The parallel type can be divided into two types according to the combination of the winding direction of coils. That is there are two cases that the coils are wound so that the magnetic fluxes induced by coils reduce and increase each other. In this paper, we called them parallel type 1 and 2, respectively. There is no significant difference in the HTS volume required to satisfy both of the specified limiting impedance ZFCL and initial current Iini in limiting operation among those three FCL's although the HTS in each type of FCL has different length and cross-sectional area. In the cases of those FCL's, we can improve the current limiting performance by arranging the HTS in the coils and applying the magnetic flux to the HTS in the limiting operation. The magnitudes of the magnetic flux density are almost the same. From the viewpoint of the FCL impedance in normal operation, parallel type 1 has the most desirable structure. On the other hand, transformer type is the best to eliminate the magnetic flux applied to the HTS in the normal operation.
