Study On Vibration And Noise Of The Transformer Core

The noise of electrical equipment has brought a negative impact on people's daily life, and the noise level has become one of the standards to measure the quality of the product, how to reduce the noise of voltage transformer also become a hot research topic. In this paper, we take transformer as the research object, study the relationship between the vibration source of the iron core and the size of the radiation noise, to provide a reference for estimating noise of at design stage transformer, thus can shorten the transformer design and production time, reduce manufacturing costs.Based on the theory of vibration and noise, firstly this paper briefly analyzes the main source of noise of transformer, the noise caused by the magnetic expansion of the iron core silicon steel sheet. Secondly, derive the sound pressure formula of the sound field radiated by the core vibration, taking a three-phase three limb transformer as the research object, and study on the core radiation noise sound field. The finite element analysis software ANSYSE is used to establish iron core instance analysis model, and to complete the electromagnetic and structural coupled analysis, the surface vibration displacement and the surface normal vibration acceleration of the iron core instance analysis model are calculated based on the analysis results, so the conditions are created to complete the analysis of acoustic radiation noise of transformer iron core. Then the calculated surface normal vibration acceleration is used as known conditions, and the acoustic analysis software SYSNOISE is taken to carry out the simulative calculation of the vibration radiation acoustic of single-chip silicon steel sheet, multi-chip silicon steel sheet and the whole iron core, and the any points of sound pressure of radiation acoustic are calculated out which is produced by iron core vibration source, as the result, the correspondence relationship is established between iron core vibration source and caused by radiation noise acoustic. Finally, compared with the transformer noise experimental data and the calculation results, the correctness of calculation and the feasible of calculation methods are verified.