Fabrication and Experimental Analysis of 6.6 kV/100 A Class Single-Phase Superconducting Fault Current Controller With Superconducting DC Reactor Coil

In this paper, we present the fabrication and experimental analysis of a 6.6 kV/100 A class superconducting fault current controller (SFCC) as a novel prototype fault current limiter. Recently, the integration of distributed generations into a grid has been issued due to increased power demand and their lower environmental impacts. The addition of distributed generators can increase the level of the fault current in the grid. To resolve the issue of increased fault current level, we propose a SFCC consisting of a superconducting coil, full-bridge thyristor rectifier, and control unit. The proposed SFCC can be described as a combination of a thyristor type solid-state breaker and a superconducting DC reactor coil. The inductance of the superconducting coil, which is about 10.4 mH, reduces the fault current amplitude. After the half cycle, through the control of the thyristors' phase angle, SFCC can control the level of the fault current to a proper level. In this paper, we present the design and fabrication of the superconducting coil, a rectifier, and a thyristor control unit. Based on the results of short circuit tests, which simulated the power grid, we expect that SFCC and its behavior can be helpful in protecting power grids from unpredictable fault currents.