Design of a superhigh-speed cryogenic permanent magnet synchronous motor

This paper presents the design and simulation of a superhigh-speed permanent magnet synchronous motor (PMSM) that operates in the cryogenic temperature of 77 K. The designed PMSM is used to drive a two-stage cryocooler for zero boil-off and long duration storage of liquid hydrogen systems. The paper addresses electromagnetic and thermal finite-element analysis, selection of materials for cryogenic applications, stress analysis, rotor dynamic analysis, and some tradeoffs used in the design. A prototype PMSM was built to verify the design methodology.