Study of Heat Localization in HTS Wires at Overload Conditions

A common problem of superconducting devices is to survive during a fault with a current overload. At a fault, superconducting device will have strong overheating and burning out is possible. The problem becomes more serious in case if a high-temperature superconducting (HTS) wire has a weak point where the critical current is less than the average over a wire. Such a weak point could be the point of origination of strong overheating within a very localized area. This can lead to burning and destroying of an HTS device. To study this problem, we developed the experimental setup with the spatial resolution 2 mm and the time resolution 1 ms to observe a local temperature/voltage evolution in HTS tapes overloaded by currents. The preliminary experiments were performed to measure local heat/voltage development on 2G HTS tapes with an artificial weak point. Local heat/voltage evolutions have been measured and compared with calculations by our model developed earlier.