Abstract: A cooling gas ventilation chimney is provided for an end region of a dynamoelectric machine having a rotor. A plurality of radial slots are provided in the rotor, and a plurality of coils are seated in the radial slots. The coils form radially stacked turns. The ventilation chimney includes one or more chimney slots that are defined in at least a portion of the radially stacked turns. The chimney slots extend in a substantially radial direction to the rotor, and at least a portion of a surface of the chimney slots is turbulated so as to have a roughened surface profile for enhanced heat transfer.

Abstract: A method of operating a power generation system and a power generation system are provided. The method includes coupling at least one electrical generator to at least one prime mover, wherein the at least one generator includes at least one of a stator and a rotor wherein at least one of the stator and the rotor includes superconducting windings therein, and coupling at least one cryogenic refrigeration system to the superconducting windings, wherein the at least one cryogenic refrigeration system is coupled in flow communication with the superconducting windings to facilitate reducing an operating temperature of the superconducting windings.

Abstract: In a ventilated cooling system for a generator, the cooling ducts in the stator are arranged to control the flow of cooling gases through the stator. The ducts in the stator extend radially and direct cooling gases from the outer periphery of the stator to its inner cylindrical surface. Cooling gases flow radially inward through these stator ducts, extract heat out of the stator and exit from the stator ducts into an annular air gap between the stator and rotor. A fan on the rotor draws the heated air out from the air gap and causes more cooling gas to be drawn into the stator. The cooling ducts in the stator are spaced and sized to optimally distribute the flow of cooling gases through the stator by equalizing the pressure drops between the stator outer plenum and the entrance to the rotor exhaust fans. For example, the stator ducts may be spaced close together at the center of the stator and farther apart near the ends of the stator to provide balanced cooling flows and uniform temperatures.