No-Insulation REBCO Field Winding Assembly for CRUISE Motor

Cryogen-free ultra-high field superconducting electric motor (CRUISE Motor) project, initiated in 2022 with ARPA-E funding, aims to develop a 10 MW, 3000 rpm machine with a power density exceeding 40 kW/kg. This paper presents a detailed progress report on the field winding development as part of the CRUISE motor project. To achieve the motor's high power density target, a field winding consisting of two no-insulation (NI) REBCO double pancake racetrack coils per pole was designed, aiming for an operating conductor current density of 500 A/mm$^{2}$ at 50 K. As part of the experimental validation, prototype racetrack coils were fabricated using an in-house winding machine and tested at both 50 K and 77 K. Based on the insights gained from the prototype coils, the coil designs were further refined and applied to the full-scale racetrack coil design. Additionally, the quench behavior of the prototype coil was experimentally investigated to verify its robustness under fault conditions.