Magnetostriction and magnetic loss variation dependent on stress for power transformer core

This study investigates extremely low noise level for three-phase three-limb transformer core, which the magnetostriction variation effect of external stress on three-phase power transformer core, with capacity of 450kVA, which induced different noise and vibration variation, is performed. It has constructed special two types of square-cored and D-yoked core power transformers and to measure magnetic properties by different stress were analyzed. The sample of silicon sheet material of 27PH100 for power transformer core has been used. The magnetostriction and B-H curve noise level and core vibration, has been measured by different external stress on transformer core. In order to compare the different results for measurement and simulation, this paper also built a simulated model for three phase power transformer. For noise level and vibration results, the external stress has performed when the core was operated at 50Hz and 60Hz. According to the measured results, it is indicated that the better stress will also be induced appropriates magnetic property which including magnetic loss, noise level and vibration.