Current-Voltage Behaviour and Surface Overheating of HTS Tapes Over Ic

Modelling and design of superconducting fault current limiters (SFCL) requires accurate prediction of current-voltage behaviour and thermal response of HTS tapes carrying electrical current over Ic, since these characteristics affect the electrical behaviour of the SFCL during a fault. An experimental method was developed to measure current, voltage and surface temperature on short HTS tapes for electrical field values above Ic (1μV/cm), up to 10mV/cm. The measurements were performed under different thermal exchange conditions with current pulses having different duration and amplitude. The experimental results allowed to validate a numerical model for HTS tapes in overcurrent conditions