Research On Electromagnetic Vibration Of Transformer Based On Magnetostrictive Equivalent Force Calculation

Low-frequency vibration and noise will be generated during the operation of power transformers,which will not only cause noise pollution,but also make components loose,which further affect the service life of the transformer.Core vibration is an important source of vibration noise of power transformers.During the magnetization process of laminated core,the vibration displacement will be caused by both electromagnetic force and magnetostrictive force.During the magnetization process of laminated core,the vibration will be caused by both electromagnetic force and magnetostrictive force.To accurately calculate the vibration of the transformer core,A joint simulation is built based on finite element method.The research work in this thesis focuses on the following aspects:(1)Based on the principle of laser micro displacement measurement,the magnetization and magnetostriction characteristics of laminated core are measured by using magnetic characteristics measurement equipment.Use interpolation calculation to convert the measured characteristic curve into a single value curve for calculation.(2)Based on the measurement of magnetic characteristics of silicon steel sheet,the model of the Epstein transformer is calculated by joint simulation.The mesh of the transformer is formed,and the magnetic field information was calculated by a multiphysical field coupling simulation software.The electromagnetic force and magnetostrictive force of the transformer core were calculated by programming based on the mesh information and magnetic field information.The magnetostrictive force and electromagnetic force were loaded on the transformer core,and the electromagnetic vibration information of the core was calculated by the coupling simulation software.(3)In order to verify the accuracy of the joint simulation results,an experimental platform was built to measure the electromagnetic vibration of the Epstein transformer.The vibration data of the Epstein transformer prototype is obtained by the vibration noise measurement system.The data calculated by the single simulation model and the data calculated by the joint simulation model were compared with the experimental results to verify the feasibility and accuracy of the joint simulation.(4)The joint simulation method is applied to the engineering prototype,and the experimental measurement of the engineering prototype is carried out to solve the problem of transformer core vibration encountered in practical engineering.