A Self-Charging Artificial Current Zero DC Circuit Breaker Based on Superconducting Fault Current Limiter

Abstract

A dc circuit breaker based on the artificial current zero can interrupt a fault current fast and at low cost. However, its working reliability is greatly reduced by a charging device of the commutation capacitor which generates the current zero. Here, a new dc circuit breaker topology that solves the pre-charging problem is proposed. A resistive superconducting fault current limiter (SFCL) is used to limit the fault current. Meanwhile, the voltage of the quenched SFCL charges the commutation capacitor. The operation principle of the proposed topology is explained, and simulations are performed to select the proper charging parameters; also, the experiments are carried out to prove the feasibility of the proposed topology. The experimental results show that SFCL voltage can charge the commutation capacitor to the level enough to generate an artificial current zero within a few milliseconds, and then, the dc circuit breaker interrupts the fault current successfully.