Flux pump excited brushless alternator

Experimental measurements obtained for a novel brushless superconducting alternator that makes use of a flux pump of the rotating spot type are presented. The flux pump, used to provide the excitation current of the field coils incorporates several features of a machine studied theoretically and reported in an earlier paper. The flux pumping is achieved with six electromagnets having pole pieces of special configurations to yield high efficiency and rapid pumping rates. The maximum design values for the current in the pump is 1,300 amps. and for the rotational speed, 500 rpm. Sensors installed on the generator yield information on the spatial and temporal behavior of the magnetic field in the flux spot and on the operational characteristics of the pump. The preliminary observations are compared with the theoretical predictions.