Superconducting Fault Current Limiter for the Electric Power System

Superconducting fault current limiters are the most attractive devices for the power network, they can be used to limit the short current in electrical network. The operation of a superconducting fault current limiter is based on the sudden transition from the superconducting state to the normal state by exceeding the critical current I-c of the material. This transition one takes a very short time, so fast that we are able to limit the first current peak to a threshold value which does not exceed three to five times the rated current. This paper presents the design, the calculated electrical parameters and tests of the medium voltage class superconducting fault current limiter prototypes made in Electrotechnical Institute. The constructed coreless superconducting fault current limiter consists of three windings: ones made of SF12050 tape and a parallel connected primary copper winding. All windings are inductively coupled and intended to work in liquid nitrogen.