Study on field-based superconducting cable for magnetic energy storage devices

During the design of superconducting magnets, the Ic(B) curve is widely used to evaluate the critical current density distribution in the magnet, safety factor is determined by the lowest value of critical current density and operating current. However, other parts of the magnets will work in over-safe state, which leads to a huge waste of superconducting properties as well as budget problem. This article presents a Field-based cable to improve the utilizing rate of superconducting magnets in SMES system. The quantity of HTS tapes are determined by the magnetic field distribution. By this approach, the cost of HTS materials can be potentially reduced. Firstly, the main motivation as well as the entire design method are introduced. Then, a typical no-insulation coil is designed and fabricated based on Field-based stacked cable to validate the feasibility of this method. Both charging/discharging test and the magnetic field test are carried out to explore the working mechanism of this coil. The unique working performance on time constant and field distribution are analyzed in detail.