Tests and Analysis of a Small-Scale Hybrid-Type DC SFCL Prototype

In recent years, high-voltage dc power transmission is widely developed in the world. However, it is difficult for the existing dc breaker to cut off the fault transmission line with large short-circuit fault current. In a short-circuit fault of dc systems, short-circuit fault current is composed of initial transient impulse current and steady-state fault current. Therefore, a hybrid-type dc superconducting fault current limiter (SFCL) is proposed with two-stage current limiting capability. In the early stage of short-circuit fault, initial transient impulse current is limited by inductance and resistance. In the later stage of short-circuit fault, a sustained and steady current-limiting resistance is provided by the dc SFCL. A small-scale prototype of the dc SFCL is developed and the parameter design of the dc SFCL prototype is presented. According to the experimental tests and simulation analysis, the design scheme's effectiveness can be confirmed from high current-limiting ratio. Based on experimental tests and simulation analysis, the current-limiting characteristics and energy loss characteristics of the hybrid-type dc SFCL have been well verified.