Fault Analysis for 110 kV HTS Power Cables

It is very attractive to replace the traditional power cables into high-temperature superconducting (HTS) cables for electricity transmission to metropolitan areas with the advantages of high capacity and low losses. However, these advantages only present when the conductors are kept in certain low temperature range. When a fault occurs, the HTS cable may quench and the resistivity of the conductor will increase rapidly which will result in the reduction of transmission capacity, increase of the power loss and even electrical insulation breakdown. Therefore, it is necessary to investigate the level of over current and overvoltage. In this paper, an accurate model for a 1-km-long 110 kV HTS cable is given and a simple simulation model for HTS cable is built up using EMTP-ATP program. Single-phase short-circuit fault and electrical insulation breakdown fault are considered to investigate the overvoltage and over current level of the HTS cable. The simulation results may provide instructive guide for the protection systems for HTS cables.