Analysis About End Electromagnetic Field And Winding Force Of1550MW Nuclear Power Generator

In recent years, with the increase of energy demand and use of non-renewableresources, nuclear power generator becomes more and more popular. With the techniqueof design and manufacture and technological level of nuclear power generator, the safeand efficient nuclear power generators have become the focus of the development ofelectric machine manufacturers in China. As the increasing of the capacity of nuclearpower generator, loss of the bar will rise and electromagnetic load will increase, theleakage magnetic flux of the end region will be enhanced, the eddy current losses of endzone structures will also be increased. The eddy current losses of end zone structureswill also be increased and the temperature of the generator will be increased. The endwinding is acted by extremely large electromagnetic forces. Insulation abrasion andfatigue fracture, even accidents will be led for mechanical vibration. Therefore, it isimportant to study the electromagnetic field of the end and the electromagnetic forcesacting on winding in order to provide more reasonable designing basis for engineeringapplications. Based on these arguments, this thesis conducts researches on theelectromagnetic field of the end and the electromagnetic force of the end windings of1550MW nuclear power generator fabricated by DongFang Electric Machinery Co Ltd.Some calculation and analysis are given which may be valuable for engineeringapplication.First of all, the research status and typical methods of the end of large nuclearpower generator and the hazard of the electromagnetic forces on the end winding oflarge nuclear power generator were summarized. Then the end structure of nuclearpower generator and mathematical model of3D end-transient magnetic fields wereelaborated. The3D full model of the end region of1550MW nuclear power generatorwas built. It consisted of stepped stator core, press fingers, press ring, copper shielding,double-layer winding of the stator and the end of rotor. Then the excitation sources instator and rotor winding were given through combination of calculation of2D magneticfield. After3D finite element meshing and treatment of boundary conditions, this thesiscompleted the calculation of transient electromagnetic fields of the end and theelectromagnetic forces acting on winding at no-load，full-load, operation under leadingpower factor. The density of magnetic flux of all structures and key points and the dataof electromagnetic forces acting on winding was obtained. At last, the comparion was completed with calculation results and the reliability ofthe method in this thesis was verified. The results can not only provide the theory prooffor improving the design and operation of nuclear power generator, but also provide thebasis for analyzing and calculating eddy current field and temperature field of nuclearpower generator under various operation modes.