基于 COMSOL 的变压器铁心振动声场分布的 有限元仿真

为了研究变压器铁芯振动噪声的分布情况，本文基于COMSOL的多物理场耦合计算分析一台200 kVA油浸式变压器铁芯振动的声场分布。首先利用COMSOL有限元计算软件，构建了200 kVA油浸式变压器铁芯振动的电-磁-力多物理场模型，计算出变压器铁芯磁场分布情况及铁芯所受应力分布变化规律、位移分布规律，并对铁芯的典型位置的应力时域数据做频谱分析，得到铁芯所受应力集中在100、200、300 Hz.再将上述多物理场计算出的铁芯表面加速度经过FFT变换后的频域数据作为声场的激励源，作声场的谐响应分析计算出变压器铁芯振动的声场分布。最后，以一台200 kVA变压器空载实验数据验证仿真数据的正确性，经过比较发现有较好的吻合效果。仿真与实验得到的一致规律是：变压器铁芯振动噪声频率集中在500 Hz以下，且发现规律：变压器油箱的侧方声压>上方声压>正面声压；变压器油箱的侧方及上方的声压频率含量是100 Hz>200 Hz>300 Hz,而油箱的正面声压频率含量是100 Hz>300 Hz>200 Hz。

Simulation and analysis of vibration and noise of oil immersed transformer core based on COMSOL

In order to study the distribution of vibration and noise of transformer core, the sound field distribution of core vibration of a 200 kVA oil immersed transformer is analyzed based on the multi physical field coupling calculation of COMSOL. Firstly, the electromagnetic force multi physical field model of core vibration of 200 kVA oil immersed transformer is constructed by using COMSOL finite element calculation software. The magnetic field distribution of transformer core, the variation law of stress distribution and displacement distribution of core are calculated. The stress time domain data of typical positions of core are analyzed by spectrum, and the stress concentration of core is 100, 200 and 300 Hz. Then, the frequency domain data of the iron core surface acceleration calculated by the above multiple physical fields after FFT transformation is used as the excitation source of the sound field, the harmonic response of the sound field is analyzed, and the sound field distribution of the transformer iron core vibration is calculated. Finally, the correctness of the simulation data is verified by the no-load experimental data of a 200 kVA transformer. After comparison, it is found that it has a good agreement effect. The consistent law between simulation and experiment is that the vibration and noise frequency of transformer core is concentrated below 500 Hz, and it is found that the side sound pressure of transformer oil tank > upper sound pressure > front sound pressure; The sound pressure frequency content on the side and above the transformer oil tank is 100 Hz > 200 Hz>300 Hz, while the sound pressure frequency content on the front of the oil tank is 100 Hz>300 Hz>200 Hz.