Development of the world's largest hydrogen indirectly cooled turbine generator

Water-cooled stator-winding generators are widely used for large capacity turbine generators of thermal power plant. However, simpler stator cooling system is preferred considering easy operation and maintenance and lower cost. Hydrogen indirectly cooled generator is one of the solution with expansion its capacity. TOSHIBA has developed, manufactured and tested 670 MVA hydrogen indirectly cooled generator. Meanwhile, higher efficiency is requested for turbine generators to reduce the global environment load. The developed generator has accomplished 99.1% of efficiency at shop test and will meet high efficiency demands. In this paper, applied technologies and shop test results of the large capacity hydrogen indirectly cooled generator are described.