Abstract
Toshiba has enlarged the capacity of indirectly hydrogen-cooled turbine generators (IHCG) with higher efficiency to reduce the CO_2 emission. IHCG has more advantages in maintenance and cost than directly water-cooled turbine generators (DWCG). We have developed high thermal conducting (HTC) insulation technology to improve the cooling performance of the stator windings of IHCGs. Developed HTC insulation had already applied to the actual 670MVA class IHCG, resulting in an increase of generator efficiency. Furthermore, we have completed the design of 820MVA class IHCGs. Currently, we are investigating higher thermal conductive HTC insulation (hereafter called the next HTC insulation) technology. In this paper, experimental results of the next HTC insulation for the actual sized stator bars were reported.