End Electromagnetic Field Analysis And Reactance Parameter Calculation Of Hydro-generator

Hydro-generator is applied more widely in the electrical power system for itsadvantages of high efficiency, no pollution, stable running and convenient maintenance.In this dissertation, taking a100kW hydro-generator model as an example, thedistribution of magnetic field for hydro-generator end region was analyzed by FEM,then the parameters under various conditions were researched, not only to provide atheory basis for the design of hydro-generator, but also providing the safeguard for thesafe and reliable operation of hydro-generatorFirstly, the end structure of hydro-generator and mathematical model of3Dtransient magnetic fields were introduced in this paper, and the3D model of the endregion of100kW hydro-generator model was established, including press fingers, pressboard, stepped stator core, the end winding of the stator and the ventilating ducts ofstator core and so on. Then the transient electromagnetic field of the end region of thehydro-generator model was analyzed and calculated in no load and rated load conditions,and the eddy current loss in the stator end structural components of hydro-generatormodel were calculated.Secondly, based on the energy method, the leakage reactance formula of stator endwas deduced, the3D mathematical model of the stator end region of hydro-generatorwas established, the energy storage of end field was analyzed with eddy current field,and the leakage reactance parameter of stator end was calculated. Then the change ofend leakage reactance without taking into account of the end structure was analyzed, thenumerical results were compared with the traditional analytic result, and the calculationaccuracy was improved effectively.Finally, the2D model of100kW hydro-generator model was established, and theexcitation currents in no load and rated load conditions were got with the method of loadimpedance. The unsaturated synchronous reactance, transient reactance and sub-transientreactance of100kW hydro-generator model were calculated by FEM, and the saturated reactance parameters were calculated under precise of accurate calculation in ratedcondition. Then, the excitation currents of synchronous motor were calculated in no loadand rated load conditions, On this basis, the changes of end leakage reactance andsaturated synchronous reactance of synchronous motor were researched.