Construction of a 100 kVA high temperature superconducting synchronous generator

This paper reports on the design and construction of the 100 kVA High Temperature Superconducting generator which is successfully built at the University of Southampton. The generator is a 2-pole synchronous machine with a conventional 3-phase stator and a HTS rotor which is constructed from stacks of 9 wt% Ni steel plates. The rotor winding is made of ten single vacuum impregnated pancake coils connected in series and operated in the temperature range 73-77 K. The relatively high operating temperatures are made possible by the use of metallic core as well as flux diverters between the coils. These coils have been successfully manufactured and tested over several cooling cycles. These provide the necessary mechanical support whilst minimizing the heat intake to the rotor core. The coils generate an air gap flux density of about 0.6 T at 77 K, while producing a perpendicular magnetic field of only 0.038 T to board face of the superconducting tape. Furthermore, the design and construction of two novel fiberglass torque tubes is also presented.