Modeling Thermal Process in a Resistive Element of a Fault Current Limiter

The thermal regime of the Ni tape immersed into liquid nitrogen and heated up due to Joule losses generated by a step-like direct current is studied experimentally and theoretically. The temporal dependence of the temperature rise in Ni tape is measured. An adiabatic approach is shown to give a conservative result. According to our results, taking into account the heat transfer by thermal conduction into liquid nitrogen is necessary. This circumstance allows one to reduce a significantly necessary amount of high-temperature-superconductor material for the superconducting part of a resistive fault current limiter.