Possibility of A Nonquench Type Superconducting Fault Current Limiter

A superconducting fault current limiter (FCL) is one of the most useful devices to stabilize the electric power network system. And many types of superconducting FCLs have been proposed and developed. For the superconducting FCL, a normal phase transition phenomenon is the most important and fundamental function to increase FCL impedance, but it thermally shocks the device and brings excessive heat load to the refrigerator. The diode-bridge type of FCL is known as a superconducting FCL that does not require a direct normal phase transition in the function; the excessive current may actually trigger the current quench of the superconducting magnet. Therefore the elaborating technology against the normal phase transition must always be considered for any type of superconducting FCL. To solve the phase transition problem of the superconducting FCL, we propose a nonquench type of superconducting FCL in this paper. The proposed FCL belongs to the LC resonance-type FCL, and superconducting magnet current in the FCL can operate under a limited value by an arrester, which makes nonquench operation possible. This paper mainly describes numerical analysis and shows the validity of the proposed FCL by means of a small experiment.