The article “Heat transfer coefficient estimation for high-temperature superconducting coils under light over-current conditions”, published in the international journal Superconductor Science and Technology (SuST), is now available. The paper focuses on the characterization of the heat transfer coefficient in superconducting coils operating under mild over-current conditions.

Among the RSE authors are Marco Bocchi, Andrea Musso and Giuliano Angeli, members of the Superconductors Laboratory of the Innovative Systems and Technologies for Energy Networks Group – Transmission and Distribution Technologies Department, as well as Francesco Mimmi, who was affiliated with the University of Bologna during the execution of the project and is now part of Active Distribution Network Technologies Group – Transmission and Distribution Technologies Department.

The study proposes an innovative experimental methodology to estimate the heat transfer coefficient of coils wound with high‑temperature superconducting tapes and immersed in liquid nitrogen, relying exclusively on electrical voltage and current measurements, without the use of temperature sensors inside the device.

The approach, validated on a prototype coil subjected to light over‑current conditions, enables an effective description of the thermo‑electric behaviour of the system, while reducing the computational complexity compared to traditional finite‑element models.

The work provides new tools for the design and reliability assessment of superconducting devices for energy applications, such as fault current limiters, energy storage systems and equipment for advanced electrical grids.