Research On Vibration And Noise Of Transformer Core Under Interharmonic Excitation

In recent years,as a large number of power electronic equipment and shock loads are connected to the grid,the complexity of harmonic problems in the power system has gradually increased,and the impact on power quality has gradually increased.The resulting interharmonic pollution problem is becoming more and more serious in the power system.Transformer as an important equipment in the power system,its vibration and noise issues have been the key research aspects of domestic and foreign experts and scholars.Its research focuses on the abnormal increase of transformer vibration noise caused by DC bias,but it is There are few researches on related issues.In this paper,based on the transformer core vibration and noise experimental platform and COMSOL multiphysics coupling simulation modeling,the vibration speed,vibration displacement and noise characteristics of the transformer core model under inter-harmonic excitation are studied.The research content of this article mainly includes the following aspects:(1)Build a transformer core vibration and noise measurement experimental platform that can generate arbitrary excitation interharmonics,measure the vibration speed waveform of the core model under normal working conditions and interharmonic working conditions,and study the interharmonics of different frequencies and contents The influence law of the wave on the vibration characteristics of the transformer core.(2)Based on the above experimental platform,the noise level of the measuring points around the ordinary silicon steel core was measured,and then the noise level time and frequency domain waveform diagrams were obtained.Analyze and summarize the influence law of interharmonic frequency and content on the sound pressure level around the transformer core.(3)Using COMSOL multiphysics coupling software,the magnetic field,structural position and sound field are coupled and analyzed,and the vibration and noise distribution results of the transformer core model under sinusoidal and interharmonic conditions are calculated under the three-dimensional transient solver.Finally,the simulation results are compared with the experimental results to verify the rationality and effectiveness of the simulation model.