Calculation Of Magnetic Field And Electromagnetic Force Of End Winding And Structural Parts Of Synchronous Generator

In this dissertation,according to the structural characteristics of the end of synchronous generator,a three-dimensional physical model and a mathematical model are established including the structure of the end of split winding,the clamping ring,the clamping finger,the guard ring and other structural parts.The magnetic field at the end of the generator is analyzed and calculated,and the distribution of the magnetic field at the end of the generator is studied.Combined with the local coordinate transformation,the variation law of the electromagnetic force of the end of the stator split winding and the structural parts under different operating conditions is given,and the influence of the material characteristics on the electromagnetic force of the structural parts is discussed.Firstly,according to the involute equation of the end winding of synchronous generator,a three-dimensional physical model of the end winding of multiple parallel winding is established,the solution area is determined,the mathematical model and boundary conditions of the magnetic field analysis of the end of the generator are given,the interaction between the linear segment and the end of the motor is accurately considered,and the three-dimensional field-circuit coupling finite element simulation analysis model is established.The magnetic field distribution of the end windings and structural parts under the steady-state operation condition is calculated,the distribution of the magnetic leakage at the end is given,and the distribution law of the magnetic field received by the end windings and structural parts is revealed.Secondly,according to the calculation results of three-dimensional transient finite element model,combined with the Lorentz force calculation method and three-dimensional local coordinate transformation,the electromagnetic force density distribution of different strand lines at the end of stator windings under rated working conditions was studied,and the flux density,electrical density and electromagnetic force density distribution rules on the clamping ring and the clamping finger were analyzed.Finally,based on the calculation results of the magnetic field at the end of the synchronous generator at the peak moment of the current impact of the strands in the three-phase short-circuit fault,the distribution law of the electromagnetic force density on the strands and structural components of the end winding was analyzed,and the electromagnetic force density in different regions of the winding were given.The electromagnetic force distribution of clamping ring and clamping finger is analyzed,and the position and direction of the maximum stress point of each structural part are given.At the same time,the influence of material properties on the electromagnetic force distribution of structural parts is studied.