Speaker
Description
High temperature superconducting (HTS) power transmission cables are cooled to operating temperatures typically below 80 K using liquid nitrogen or gaseous helium. HTS cables are being considered for use in connecting substations to allow transformers to share load, or for long distance, low loss electrical power transmission. One interesting feature of HTS cables is that they have been shown to limit short circuit fault currents, which can be more than ten times the maximum operating current of a cable. When a fault occurs, the cable current exceeds the critical current of the HTS material, and the cable operates in a resistive mode for a short duration (nominally four ac cycles). During this short time, a significant amount of energy is dissipated in the cable and the cable will heat up above its normal operating temperature and must cool down before it can be returned to service. The recovery process of a high temperature superconducting power transmission cable involves several factors include the cooling scheme (counterflow or parallel flow), the refrigerator system performance with load and temperature, the energy deposited during a fault scenario, and the operating temperature margin. This is an investigation into the thermal recovery after a fault for some different HTS cable system configurations and operating conditions.
