Analyses Of the Active Superconducting Fault Current Limiter Simulations and Experimental
In this paper the operation principle of a new type of active superconducting fault current limiter (SFCL) is given. The SFCL consist of an air-core superconducting transformer, a PWM converter and a superconducting magnet. The air-core superconducting transformer primary winding is in series with AC main circuit, and the second winding is connected with the superconducting magnet all the way through a PWM converter. In normal (no fault) operation state, the flux in air core is compensated to zero, so the SFCL has no influence on main circuit. In the case of short circuit, by controlling the amplitude and phase angle of the second winding’s current, the limiting impedance which is in series with the AC main circuit can be regulated and the fault current will be limited to a certain level. Using SIMULINK, the simplified model of the active SFCL is created, and simulations validate this SFCL can suppress the fault current efficiently. Also the current-limiting experiment is done with a small conventional transformer. Experimental results are similar as that of simulation results.