Design Procedure of a Hybrid YBCO- Superconductor Fault Current Limiter (SFCL) for a High Voltage Substation

In modern electric power systems, the increasing amount of on-site generation should be integrated into the power-grid. This translates to more sophisticated electric network with intrinsically high short circuit current capacity. A superconducting fault current limiter (SFCL) is taken as a solution to increase safety margin of circuit breakers (CBs) of the substation. SFCL is a device with negligible impedance under normal operating conditions that immediately switches to a high impedance state in case of over-current. At AkAki II substation, 230 kV bus-bar, a hybrid-resistive SFCL is designed. The design procedure encompasses collection of the substation data, short-circuit analysis of the substation, and designing of all parts of the SFCL. The Matlab/Simulink simulation result shows that the SFCL can minimize the maximum short-circuit current from 44 kA to 35 kA. The whole system can be implemented by $320,000/phase in 10m × 20m area by 1.8m height space of the substation.