Numerical investigation of stator main insulation temperature field for large generator

To explore stator temperature field and distribution principle of major insulation temperature drops inside large turbo-generator. A large generator with different structure strands is taken as an example, according to ventilation performance and structure characteristic of generator, two dimensional fluid field model inside stator radial duct was given and it was numerically calculated using finite volume method (FVM). Meanwhile, the mathematical model and physical model of three dimensional stator temperature field were established for generator with different structure strands and it was numerically analyzed by finite element method (FEM) baesd on getting the heat transfer coefficients of all heat transfer surfaces. Investigation results show that calculated results of temperature correspond with measures results, the highest temperature is located on the strand of upper bar adjacence to stator notch, maximum and anerage value of major insulation temperature drops of upper and bottom bar are not same, and temperature drops of upper bar are bigger than that of bottom bar. Thus the theoretical foundation can be offered for large generator strands structure optimization.