POSITION OF QUENCH INITIATION IN 6-KV-200-A-CLASS SUPERCONDUCTING FAULT CURRENT LIMITER

We have developed a 6 kV-200 A class superconducting fault current lim iter (SC-FCL). The SC-FCL has eight co-axial coils connected in order to minimize total inductance. In the present paper, taking considerati on of the self-magnetic field in the SC-FCL, we discussed the position of quench initiation. We calculated spatial profiles of the strength and the direction of the self-magnetic field in the SC-FCL. As a resul t, the self-magnetic field is applied to almost sections of the superc onducting cable (SC cable) in transverse direction (maximum value : 6. 42x10(-4) T/A). The connective section between coils, however, suffers the magnetic field with longitudinal component of 3.34x10(-4)T/A. In the case of a short sample of the SC cable which was used for the SC-F CL, the quench current levels were measured to decrease at the rate of 40 A per 0.1 T in transverse magnetic held and 100 A per 0.1 T in lon gitudinal one. Taking these results into consideration, we pointed out that the quench may be initiated in the connective section between co ils where the self magnetic held is applied in the longitudinal direct ion.