DC motors with high-critical-temperature superconducting field winding and slotless armature

The paper describes the design and characteristics of high-power DC motors combining a superconducting field with a slotless, multiplex armature. This type of armature allows the motor to be designed with ratings much higher than is otherwise possible. The high-critical-temperature superconducting field winding provides a relatively simple, lightweight excitation system. A special winding is proposed as a means of avoiding torque reaction at the field winding and the resulting force which would need to be transmitted through the cryostat. The design of a 1O MW 150 rev/min motor is presented as an example and compared with a conventional design for the same specification. The superconducting, slotless machine has about half the weight and half the loss of the conventional machine