中文摘要：

超高压电力变压器本体振动噪声主要来源于铁芯磁致伸缩,为了准确计算变压器铁芯磁致伸缩效应,提出了基于磁致伸缩力–热应力比拟的数值计算方法。首先采用ANSYS有限元分析软件建立电力变压器3维瞬态电磁场数值计算分析模型,通过求解提取铁芯每个节点不同时刻的的磁密值;其次根据磁致伸缩力–热应力的比拟,加载试验测得的硅钢片磁致伸缩特性曲线,计算得到铁芯不同时刻各个节点的磁致伸缩力;然后将铁芯磁致伸缩力导入到结构场和声场计算模型中,求得铁芯本体的振动位移及其声压分布;最后对通过减小磁密来降低铁芯本体振动噪声的效果进行了分析,并对比了不同磁密下铁芯本体振动噪声的强度与分布,证明了该方法的有效性,对比结果表明铁芯磁密降低0.05 T,其声压最大值降低约1.26 d B。

英文摘要：

The noise and vibration of EHV power transformer originate mainly from the magnetostriction of the core. In order to accurately calculate the transformer core magnetostrictive effect, we proposed the magnetostrictive numerical calculation of force-thermal stress comparison. Firstly, we used the ANSYS finite element analysis software to build 3D transient electromagnetic field numerical calculation model of power transformer, and solved the core flux density values at different times for each node. Secondly, according to the magnetostrictive force-thermal stress comparison, we loaded the tested magnetostrictive characteristic curves of silicon, calculated the magnetostrictive force on each node of the core at different times, and leaded the core magnetostrictive force into the structure field and sound field calculation model to get the sound vibration displacement and sound pressure distribution of the core body. Finally, we analyzed the effect of reducing the core body vibration noise effect by lowering the flux density, and compared the intensity and distribution of core body vibration noise at different flux densities, demonstrating the effectiveness of this method. Comparative results show that the core flux density reduces by 0.05 T and the maximum sound pressure is reduced by about 1.26 dB.