Analysis Of Rotor Temperature Field Of Hydro Generator On Asymmetric Operation Condition

The finite-element method had been taken in analysis of hydro-generator's electromagnetic field and temperature field on asymmetric operating conditions.Firstly, the 2-D time-harmonic and time-stepped movement electromagnetic field models and the steady-state and transient temperature field models had been established. The field-circuit coupled, the rotating of the rotor, the difference between the windward side and the wind surface, and the coupled field solving method of electromagnetic field and temperature field had been discussed. The determining of the current and loss of damper windings, the loads and the thermal coefficient of temperature field had been studied.Secondly, steady-state finite-element analysis of the electromagnetic field and temperature field had been taken on the steady negative-sequence operating condition of hydro-generator. The accurate distribution of electromagnetic field and temperature field had been obtained. And the distribution law had been summarized. The impact on temperature field of the additional loss of pole surface, the modeling of the damper air-gap, the coupled field method to apply load had been studied.Thirdly, transient finite-element analysis of the electromagnetic field and temperature field had been taken on the rated operating condition and the sudden single-phase ground short-circuit fault, sudden two-phase short-circuit fault, sudden three-phase short-circuit fault that based on the rated operating condition. The distribution law of electromagnetic field and temperature field, and the curve of the torque, the stator current and the damper winding loss and current over time had been obtained. The harm degree of every sudden short-circuit fault had been determined.The study is very important to the design and the operation of hydro-generator. It is also very important to the safe operation of the whole power system. It has very high value to engineering and academic.