HTS Conductor for Superconducting Fault Current Limiting Transformer

摘要

With the increasing power grid capacity and voltage level, the fault current of the system is getting higher, which will have a great impact on the economy of the region and the safety of the power system. In order to solve this problem, the researchers have developed a variety of superconducting fault current limiting devices based on the characteristics of the second-generation (2G) high-temperature superconducting (HTS) tapes with high resistivity after quenching. Among them, the superconducting fault current limiting transformer (SFCLT) has the dual functions of a transformer and a fault current limiter. In this paper, an HTS conductor for superconducting current limiting transformer is proposed. Based on the short circuit fault current of the secondary winding of 120 kVA HTS transformer, the specific structural parameters of the conductor are given. On the basis of the parameters, combined with the numerical analysis of conductor's circuit and thermal equations, the critical current and current limiting characteristics of the conductor are obtained by modeling and simulation. The simulation results show that the conductor can limit the fault current well, and it is a scheme for the superconducting current limiting transformer winding.