Analysis And Calculation Of 3D Electromagnetic And Thermal Fields In End Region Of Steam Turbo-generators

With the advancement of computer-aided design and the development of construction material,insulation material,conductive material,magnetic material,air-cooling steam turbo-generator has had more rational structure , bigger capability,higher-performance,and its rating operation efficiency has been equated with the hydrogen-cooled turbo-generator with the same capability.And the structure of air-cooling steam turbo-generator is simple,performance is on the safe side,it is being taken more seriously,so detailed studies to air-cooling steam turbo-generator have great significance.Firstly,2D model of 150MW air-cooling steam turbo-generator is built in this paper,and getting the excitation source in stator and rotor winding on full-load condition through saturated and end-point condition iteration to 2D magnetic field . Then elaborating the end structure of steam turbo-generator and mathematical model of 3D end-transient magnetic fields,and building the 3D full model of the end region of air-cooling steam turbo-generator.It consist of press ring,magnetic shielding,press board,press fingers,the end of stator and rotor core,the end of stator and rotor winding,and consider the effect of ventilating ducts in the end region of stator core to parameter of end region.Then this paper complete the calculation of end-transient magnetic fields and eddy current loss in the end-generator,gaining the density of magnetic flux and losses of all structures and key points.Secondly,based on the calculation of end-transient magnetic fields,this paper proposes a method of calculating thermal field,which through the losses from 3D end-electromagnetic fields and the surface heat transfer coefficient from analytic method.And the calculation of the thermal fields in end-stator region of air-cooling steam turbo-generators is finished, temperature rise of every structure and key point is got.Finally,on the condition that meeting the project,this paper proposes a method of calculating rotor thermal field,which through delicate the 3D-rotor model and state thermal field.The option and improvement of model in calculation is showed and the effect of radial vent in rotor windings and cooling ducts in the end of rotor windings to rotor temperature rise is considered.In the end the distributions of rotor temperature fields is gained.