Numerical analysis of the stability of HTS power cable under fault current considering the gaps in the cable

•The equivalent circuit equations and the heat balance equations were established.•The current distributions of the HTS cable under fault current were obtained.•The temperature curves of conductor layers under fault current were obtained.•The effect of the gap liquid nitrogen on the thermal characteristics was studied.

During the operation of a high temperature superconducting power cable in a real grid, the power cable can be impacted inevitably by large fault current. The study on current distribution and thermal characteristics in the cable under fault current is the foundation to analyze its stability. To analyze the operation situation of 110 kV/3 kA class superconducting cable under the fault current of 25 kArms for 3 s, the equivalent circuit equations and heat balance equations were established. The current distribution curves and the temperature distribution curves were obtained. The liquid nitrogen which exists in the gaps of HTS cable was taken into consideration, the influence of gap liquid nitrogen on the thermal characteristics was investigated. The analysis results can be used to estimate the security and stability of the superconducting cable.