The large-capacity high-frequency transformer(HFT)has a compact structure,with a working frequency ranging from several hundred Hz to tens of kHz,and operates with special excitation waveforms such as square waves and other non-sinusoidal waveforms.The high-frequency transformer is characterized by coupling between multiple fields,including electromagnetic,structural,and acoustic fields,resulting in serious vibration and noise problems during opera-tion.A detailed analysis of the vibration and noise characteristics of high-frequency transformers is of great significance for reducing noise.Therefore,this paper first establishes a three-dimensional simulation solving model of electromagnetic field+structural force field+acoustic field of HFT,and clarifies the load transfer process of each physical field as well as the electromagnetic and mechanical performance parameters.Then,the finite element method is used to obtain the time-domain vibration waveform and frequency-domain noise characteristics of the transformer core surface under dif-ferent voltage excitations,and the influence of nanocrystalline cutting core on the mechanical characteristics is quantitatively evaluated.Finally,the vibration and noise of a 5 kHz/10 kVA HFT are tested,and the core vibration and noise data under sinusoidal and square wave voltage excitation are obtained.According to the simulation and experi-mental results,the vibration at the corner of the high-frequency transformer core is more severe and the noise generated around it is also larger.Compared with the sine wave excitation,the vibration under non-sinusoidal excitation not only concentratively occurs in the double frequency,but also has many higher harmonic components,and the sound pressure level in each frequency band increases significantly.The relative error of the sound pressure level at the measurement point is within 10%under different waveform excitation,which verifies the accuracy of the simulation model.
关键词
电磁-结构-声场分析/振动噪声/高频变压器/电磁振动/频域特性/振动加速度
Key words
electromagnetic-structure-acoustic field analysis/vibration noise/high-frequency transformer/electromag-netic vibration/frequency domain characteristics/vibration acceleration
维普
万方数据