Current progress in high thermal conducing insulation technology for large capacity turbine generator

We have enlarged the capacity of indirectly hydrogen-cooled turbine generators to improve the efficiency, simplify the machine structure and save the maintenance cost over the past decade. The one of the key technologies is the heat transfer from a stator bar conductor to iron core, because indirectly hydrogen-cooling performance is inferior to directly water-cooling one. So, we have developed High Thermal Conducting (HTC) insulation technology and achieved twice of thermal conductivity compared to conventional epoxy-mica insulation [1]. Recently, we have achieved further improvement in thermal conductivity of HTC insulation. The progress of HTC insulation technology is reported in this paper.