Comparing Copper With Stainless Steel as a Stabilizer Layer in Resistive Superconducting Fault Current Limiters

Abstract

The increasing penetration of renewable energy sources (RESs) into electrical networks offers several interesting opportunities and challenges. One such opportunity is the utilization of DC transmission lines, which can enhance the efficiency and reliability of power transmission. However, DC transmission lines face a challenge in dealing with fault currents due to their high magnitudes and the absence of zero crossing points, characteristics that make it difficult for DC circuit breakers (CBs) to clear faults. Resistive superconducting fault current limiters (r-SFCLs) effectively minimize high magnitude fault currents, allowing DC CBs to operate safely during fault scenarios. The self-triggering feature and fast fault current limitation ability of r-SFCLs also make them particularly suitable for protecting against high DC fault currents. Several studies demonstrated the performance of r-SFCLs with one type of stabilizer layer, most commonly using either copper (Cu) or stainless steel (SS). This paper investigates and compares the performance of an r-SFCL with the two different stabilizer layers, with one case using copper and the other using stainless steel. A thermoelectric r-SFCL model incorporating all composed layers has been developed in Simulink/MATLAB® to investigate the performance of the r-SFCLs with the two different stabilizer layers. The r-SFCLs have been evaluated using different fault scenarios applied to the DC transmission lines of a solar farm. In this model, all r-SFCL layers, excluding the stabilizer layer but including the superconducting, silver, and substrate layers, have been fixed to show the impact of the stabilizer layer materials on the r-SFCL’s performance. This paper illustrates the fault current limiting capability of the r-SFCL, its effect on voltage behavior, its operating temperature, and its sensitivity to the fault location with the two different stabilizer layers. To simulate a range of fault levels and assess the limitation capability of the r-SFCLs, three distinct fault locations have been considered: one located 5 km away from the solar farm, another 15 km away, and a third 25 km away.

Keywords

• Resistive superconducting fault current limiter (r-SFCL)
• stabilizer layer
• solar farm
• DC transmission lines
• stainless steel