Numerical analysis and electrical insulation design of a single-phase 154 kV class non-inductively wound solenoid type superconducting fault current limiter

The electrical insulation design of high voltage superconducting fault current limiters (SFCLs) should be confirmed for the stabilization of the power grid. This paper describes numerical analysis for high voltage SFCLs based upon the AC and lightning impulse dielectric tests. To calculate the field utilization factor, the electric field distributions for numerical analysis were calculated by finite element method (FEM) simulation tool. The correlation of experiments results and the field utilization factor was investigated. From the results, the electric field criterion of liquid nitrogen at 200 kPa was calculated. Furthermore, safety factor was also considered to design single-phase 154 kV class SFCL. This insulation design in liquid nitrogen focused only two parts of SFCL. Part 1 is gap distance between a cryostat and superconducting coils. Part 2 is gap distance between series-connections of non-inductively wound solenoid type coils.