Conceptual Design of a 200-kJ 2G-HTS Solenoidal $\mu$ -SMES

The conceptual design of a 200-kJ micro Superconducting Magnetic Energy Storage (μ-SMES) system is presented as a complementary technological solution to existing Uninterruptible Power Supplies (UPS) for applications in computer servers ensuring power stability against short-duration faults. μ-SMES systems to the contrary of batteries have a long life cycle and present a lower environmental impact. The magnet is made of 31 pancake coils connected in series, wound with 12-mm-wide Cu-stabilized 2G-HTS wire, and operated in liquid nitrogen at 65 K allowing to achieve 200 kJ of available stored energy and 52 kJ of disposable energy for the basic operation of the μ-SMES system. Magnetostatic analysis based on a proposed critical surface for 2G-HTS wire allows to obtain the number of pancake coils and the operating temperature of the superconducting magnet. Based on the obtained results, a structural analysis is discussed showing that the current design at the final operating point does not present any concerns in terms of mechanical induced degradation of the superconductor and of structural failure.