A DC-operating resistive-type superconducting fault current limiter for AC applications

The feasibility of a novel type of superconducting fault current limiter (SFCL) based on the synergy of the resistive and the rectifier concept is investigated. The proposed SFCL acts as a resistive type in the limiting phase whereas in normal operating conditions it operates as a rectifier, thus avoiding true AC currents and related AC losses in the superconductor. The concept of a DC-operating resistive-type SFCL (in short a DC resistive SFCL) is illustrated and the design parameters of the device are derived with reference to a practical application to the distribution voltage level. The design of the rectifier bridge by means of commercially available discrete diodes and the estimation of the total power consumption due to these components is carried out. Finally, the feasibility of the DC resistive SFCL by means of present state of the art superconductors (including 1 and 2 G high temperature superconductors as well as MgB2) is discussed, and a comparison with the conventional AC resistive concept is given.