The superconducting generator development program in Japan

This paper is the summary of a government-sponsored feasibility study on superconducting generator, related machines and materials which extended over 1985 and 1986 fiscal years. The study attempted to scale the merits of the superconducting generator in its life time cost and cost saving effect over conventional machines within a introduction scenario but the scope of the study covered also the stabilization effect, its impact on the power grid and the thorough examination of technological problems. In this context, superconducting machines can be in competition with conventional machines with PSS, so one of the chief targets of the study was the possibility of High Speed Initial Responce (HSIR) Machine with supercon-ducting field coil. The study showed that, a) using the existing materials and designs it will become possible to construct a superconducting generator with an HSIR rotor after several years of development, b) with high voltage forcing, it will be possible to attain more than 30% increase of grid stabiiity with generators of small Xdand the economical break-even will be attained around the generators of capacity from 300 MVA and more, c) but generators with HSIR rotor present new design problems such as the compromise of the heat dissipation and the electrical insulation which can only be solved by experiments done on highly sophisticated models.