Mechanical and thermal design of the EPRI/Westinghouse 300 MVA superconducting generator

Westinghouse Electric and the Electric Power Research Institute (EPRI) are engaged in a joint program to develop a 300 MVA generator with a superconducting field winding to demonstrate the increased efficiency, reliability and stability of such units as base load generators. Considerations such as conductor support, transient heating, electrical damping, magnetic shielding and dynamic stability demand creative structural and thermal designs. Unique structural designs are required to support the rotor damper shield and to limit transient torsional loads under fault operation. The rotor cooling system is designed to remove the shielding losses induced by fault operation as well as those encountered during steady state operation. So effective is the cooling system that the winding can undergo resistive transition over a large portion and still recover the superconducting state. The conceptual design of the 300 MVA rotor is reviewed. The structural design and calculated performance of the cooling system during steady state and fault operation are presented. The opportunities presented by new materials and manufacturing technology are summarized. Future developments, and model testing anticipated during the program are reviewed.