The generator stator adopts a closed oil-cooling system, and there is an oil separator (epoxy resin board) in the air gap whose purpose is to ensure the cooling medium flowing through the sta-tor slot space and the yoke back space. The thermal conductivity of the cooling medium is 0.129 W/(m·°C). Its specific heat ca-pacity and fluid density are 1000 J/(kg·°C) and 895 kg/m3 .The stator windings and the cooling system are shown in Fig. 8.