Design of a High- $T_{\text{c}}$ Superconductive Maglev Flywheel System at 100-kW Level

The flywheel energy storage system (FESS) is an ideal candidate for electrical energy savings in subway systems when combined with regenerative braking technology. Practical application in a subway system requires a FESS with large energy storage capacity (ESC), high power level, short recharge interval times, and high recharge cycles. The high-T _c superconductive (HTS) Maglev bearing can levitate and rotate a heavy rotor stably at a high speed, which can improve the performance of a FESS in subway systems dramatically. The authors designed a FESS prototype based on an HTS Maglev bearing, with a maximal power level of 100 kW and a maximal ESC of 5 kWh. This paper introduces the design and manufacturing process of this FESS prototype, including the major components such as the HTS Maglev bearing, the permanent-magnet synchronous motor, the composite flywheel rotor, and so on. The conclusions of this paper are useful for the design and application of HTS Maglev FESSs.