Abstract: The thermal fault caused by the blockage of the internal cooling water system of the stator winding of the generator is one of the main faults of the turbo generator.However,it is difficult to find the problem of abnormal arrangement of generator temperature measuring points or slight blockage in the hot water flow test and ultrasonic water flow measurement method when the generator is stopped,and the false alarm of the high temperature of the stator bar outlet water occurs from time to time.In order to reduce the false alarm rate in generator operation,the analysis method of generator hot water flow test was improved.The criteria for quantifiable evaluation of the fluidity of internal cooling water system in generator stator winding were studied.Through the correlation analysis and linear fitting of the“time-temperature”curve data in the actual case,a general and feasible analysis method in the operation of generator and hot water flow test was established based on the Fourier heat conduction law.Compared with the traditional means of monitoring temperature difference,the method proposed has higher accuracy and theoretical basis,and has a significant effect in reducing the false alarm rate.