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 d B.