Development of conductors for superconducting generators

Basic design studies are conducted for 7-MVA superconducting generators, and superconductors are developed. For generators, it is intended to develop a slow-response-excitation-type generator with emphasis placed on stability and higher current density, and a quick-response-excitation-type generator with reduction of AC loss for enhancing the excitation speed. Three kinds of NbTi field windings for these superconducting generators were designed and developed with targets set for the conductor size, critical current, AC loss, void fraction, etc. The development of a conductor processing technique, improvement of the heat treatment technique, and development of a composite stranded wire technique were pursued. For Nb/sub 3/Sn conductors, research was conducted to enhance the current density of strands and their workability by a bronze process and an in situ process.