Research on Thermal Problem in the End Region of a Large Turbogenerator

In this paper, the electromagnetic and temperature field of the end region of a 350-MW double-water internal cooling generator was calculated. By observation and measurement, it was found that the maximum surface temperature in excitation side of a generator operating in a nuclear power station is a little high so that there is a safety hazard. A 3-D transient electromagnetic model of the end structure was built, including the end of stator and rotor winding, the end of stator and rotor core, outer wall, press board, magnetic shielding, press ring, copper shielding, and outer magnetic shielding. The eddy-current losses and iron losses of the end parts are calculated, as the heat sources basis of temperature distribution calculation. Comparing the calculated temperature results with the measured value, some measures to reduce the temperature are proposed for better performance.