Patent ID: 7291958
Filing Date: 2007-11-06
Classification: H02K,Y02E

Abstract:
1. A synchronous motor/generator, comprising: a drive shaft; a rotor coupled to the drive shaft, the rotor comprising at least one rotor winding; and at least one back iron separating at least one stator winding and the at least one rotor winding from an outer motor frame such that the at least one back iron shields the outer motor frame from the at least one stator and rotor winding, the at least one back iron is coupled to the drive shaft and rotates with the rotor such that the at least one rotor winding generates DC fields when it rotates, to mitigate losses of a rotating magnetic field created by the at least one rotor winding; and the motor/generator is a superconducting synchronous motor/generator having an air-core geometry and a cryogenic environment for thermally insulating the rotor wherein the at least one back iron being located within the cryogenic environment.