Research On Transformer Core Vibration Based On Finite Element Method

With the continuous development of my country’s power industry,transformers play an increasingly important role in the transmission process of the power system.Especially in the current united efforts to fight against the new crown pneumonia epidemic,electric power workers have completed the task of transmitting power to new lines quickly and successfully many times.When the power transformer is operating in a steady state,its body will inevitably vibrate,and the vibration will not only bring safety hazards to the transformer,but also cause noise pollution due to vibration.The vibration and noise mainly come from the magnetostriction of the iron core silicon steel sheet.Research on transformer vibration and noise by Chinese and foreign scholars is also based on the phenomenon of iron core magnetostriction.In order to better analyze the vibration law of the transformer core,reduce the impact of transformer noise on residents’ lives,and provide support and reference for the stable operation of the transformer.This paper mainly studies the transformer core,and then conducts a systematic theoretical analysis of the vibration characteristics of single-phase and three-phase power transformer cores.The magnetostrictive characteristics of the transformer core are analyzed,the correlation between the vibration of the transformer core and the amplitude of the excitation voltage is studied,and the vibration characteristics of the transformer core when the excitation voltage exceeds the rated voltage are studied.The main work content is as follows:Firstly,the propagation path of transformer vibration and the mechanism of transformer core vibration are studied,and then it can be derived from the formula that the magnetostriction of the core is related to voltage.Then on the basis of the above work,using Comsol Multiphysics multiphysics simulation software,a single-phase transformer core vibration electric-magnetic-force multiphysics model was constructed to obtain the magnetic field distribution of the transformer core,and then use the established model to compare The vibration deformation of the iron core under the action of the magnetic field is analyzed.Finally,the vibration characteristics of the transformer core under different excitation voltages are analyzed,and the distribution law of the stress and deformation of the single-phase transformer core is obtained.Finally,a three-phase power transformer with model S13-M-400/10 and connection group YNd11 is used as the simulation object.Study the influence of the operating overvoltage caused by closing on the vibration characteristics of the transformer.First,establish a transformer model under no-load,simulate it when it is closed,and interpolate the simulated transformer voltage waveform results into the voltage excitation of the established three-phase transformer electric-magnetic-force multiphysics model.No-load vibration simulation of the three-phase transformer.By analyzing the effect of overvoltage on the magnetic field and stress of the transformer core,it has practical significance for vibration reduction and noise reduction and the safe operation of the power system.