Design and Performance Analysis of a Saturated Iron-Core Superconducting Fault Current Limiter for DC Power Systems

Abstract

A saturated iron-core superconducting fault current limiter (SI-SFCL) can significantly limit the magnitude of the fault current and reduce the stress on circuit breakers in direct current (DC) power systems. The SI-SFCL consists of three main parts: one magnetic iron-core, one normal conductive primary coil (CPC), and one superconducting secondary coil (SSC). This paper deals with the design options for the coil system of the SI-SFCL and confirms their operating characteristics through a physical experiment. The electromagnetic characteristics and operational features of the SI-SFCL was analyzed by a 3D finite element method simulation model. The design of the SSC was based on shape, wire types, required fault current limit and protection aspects. In the CPC, the bobbin was designed based on material selection, cost, structural design, and the effects of the SI-SFCL on the fault current limit. Based on these simulation results, a laboratory-scale SI-SFCL was developed, specifically fabricated to operate on a 500 V, 50 A direct current (DC) power system. In the experiment, the operating characteristics of each coil were analyzed, and the fault current limit of the SI-SFCL according to the operating currents of the SSC and bobbin design of the CPC were confirmed. Finally, the cost analysis of the SI-SFCL with the proposed design options of the coil system was implemented. The results obtained through this study can be effectively used to large-scale SI-SFCL development studies for high-voltage direct current (HVDC) power systems.

Simulation of a Low-Voltage Direct Current System Using T-SFCL to Enhance Low Voltage Ride through Capability

“…In the normal state, the resistance of the HTSC element is zero. Therefore, T-SFCL has an advantage in that it does not affect such as system loss [20][21][22][23][24][25][26].…”

Superconducting Electric Power Systems: R&D Advancements

“…Therefore, SFCLs are used to limit the DC current in fault conditions, to ease the burden of DC circuit breakers (DCCB). The work from Dao and Lee et al [13,15] study the use of a Saturated Iron-Core Superconducting Fault Current Limiter (SI-SFCL) for DC power systems. SI-SFCLs are SFCLs that use a transformer configuration, such that the primary side is connected to the DC power grid, and the secondary side is connected to the SFCL.…”

“…This results in a lower peak fault current and higher rise time. For the research of SI-SFCLs, Dao et al [13] developed in 2020 a laboratoryscale SI-SFCL to operate at 500 V, 50 A, and with a DC power system. Experiments were set up to analyse operating conditions and characteristics of the SI-SFCL regarding the characteristics of the coils of the primary and secondary side.…”

Combined Operation Analysis of a Saturated Iron-Core Superconducting Fault Current Limiter and Circuit Breaker for an HVDC System Protection

“…The fault current simulation result is shown in Figure 3b. The detailed design of the SI-SFCL covered in this session was performed in the author's previous work [36,37]. The SI-SFCL has a structure similar to that of a singlephase transformer as described in Section 2.1.…”