Output power limit of 200 MW class brushless superconducting generator excited with magnetic flux-pump

A study on excitation system would be important to enhance potentials of superconducting AC generators. The authors have fabricated a 20 kW class fully superconducting machine with the brushless excitation system which consists of a magnetic flux-pump. By many tests of power generation using this machine, they have investigated theoretically and experimentally the feasibility of the brushless superconducting generator and magnetic flux-pump. Based on these results, this paper proposes the conceptual design and electric characteristics of a practical scale flux pump for an exciter system of a 200 MW class superconducting generator (Super-GM). Furthermore, the paper presents a comparison of output power limits for such as different excitation methods; a persistent field current mode and a conventionally adjusting field current mode