Design and Study of a 2G HTS Synchronous Motor With Brushless HTS Flux Pump Exciters

A high temperature superconducting (HTS) synchronous motor with brushless HTS flux pump exciters was designed and is under construction. This HTS synchronous motor is composed of copper armature windings, HTS field windings, HTS flux pump exciters, vacuum chamber, rotary gas seal, etc. The double racetrack-type HTS field coils are wound with second-generation (2G) YBCO tapes and cooled directly by the cold heads. The designed operation temperature is about 30 K. An HTS flux pump was designed to be used as DC power supply to inject large currents into the HTS field coils, which eliminates the slip ring in the motor and avoids thermal load from current leads. The novel design of multiple sources enables us to control the excitation current of the HTS field winding for each pole separately and to prevent all the series field coils from stopping at the same time due to the quench of one coil. To describe the performance characteristics of the HTS motor, an electromagnetic design was carried out with 2-D finite-element method models. Finally, the total losses of HTS synchronous motor are calculated. The next step is to manufacture and install the HTS exciters, HTS field windings, etc. into the HTS synchronous motor.