Research On The Stator Temperature Model And Its Condition Monitoring Application Of Turbogenerators

This paper develops the mathematic model of turbogenerators stator 3D temperature filedand stator end region temperature, and researches the application of temperature model in thecondition monitoring in detail. The main achievements are as following:1. This paper sets up a mathematic model of the stator 3D temperature filed ofturbogenerators cooled by water, hydrogen and hydrogen that is applied in the conditionmonitoring of turbogenerators. The model settles the determination method of coolingliquid temperature in convection radiating-heat boundary, and couples the solid and liquidtemperature. And we have studied the numerical solution method of 3D temperature filed.Based on the equivalent thermal net method, the stator temperature model is dispersed tonon-linear equations, and we can simultaneously solve the equations of solid and fluid byusing iteration method. Using this mathematic model, we can calculate the stator 3Dtemperature filed when turbogenerators operate in normal and fault states, and suppliescriterion for the condition monitoring of turbogenerators.2. This paper puts forward the determination method of temperature standard value of statoriron, winding and cooled water of turbogenerators when operate on steady state andload-variation state. Based on the calculation result of stator 3D temperature filed whenturbogenerators operate normally, this method can simultaneously determine thetemperature standard value of various stator positions. And this paper also puts forwardthe simple element method and multi-cell circuit method that aiming at the temperaturemonitoring of stator bar and cooled water, they satisfy precision expect and savecalculation time.3. This paper studies the stator 3D temperature filed and temperature character whencooling system of turbogenerators is blocked. The results show that the numbers andposition of blocked hollow strands directly influence the water quality and temperature ofout-water and slot thermometer, and more concentrative the position of blocked hollowstrands and more number of blocked hollow strands is, then higher the temperature ofout-water and slot thermometer is. Based on this, the paper puts forward the diagnosismethod of cooling system blocked. The method can diagnose the position and severitydegree of blocked hollow strands by analyzing temperature variation of out-water and slotthermometer.4. This paper sets up the mathematic model of temperature of turbogenerators stator endregion. The model describes the mathematical relationship between the temperature ofstator end region and operation state parameters(active power, inactive power, armatureterminal voltage, pressure of end cooling medium and flow) of generator. And the paperalso studies the method that determine the model parameters in use of the operation stateparameters, and deduces a new temperature-rise limit curve of stator end region that canbe used to guide leading operation of generators.5. This paper develops the software of turbogenerators stator 3D temperature filedcalculation. The software have configuration and modularization characteristic, and cancalculate stator 3D temperature filed when generators operate in normal and heat-faultstate, and consequently realizing the stator thermal condition monitoring.