The brushless excitation system

A NEW TYPE of excitation system has been developed for use in the electric utility industry in which the generator collector and collector brushes, and the exciter commutator and commutator brushes are eliminated. The basic difference between this system and its predecessors is an a-c exciter mounted on the same shaft as the generator field. This innovation introduces a much shorter exciter time delay due to the fact that a 420-cycle a-c exciter has replaced the conventional d-c exciter which is inherently slower. The smaller time delays make the system easier to stabilize and improve the over-all system response.