Research on vibration and noise of transformer under DC bias based on magnetostriction

The phenomenon of direct current (DC) magnetic bias is main cause of the increased noise and vibration of the transformer core and the magnetostriction is main cause of noise and vibration. This paper studies the magnetostriction characteristics of grain-oriented (GO) electrical silicon steel sheets. Especially the anisotropic magnetostriction along the rolling direction (RD) and transversal direction (TD) deviating from RD 90° was measured based on a standard single sheet measurement system, and the single-valued curves of magnetostriction were obtained to applied in the calculation of finite element (FEM). The vibration and noise of a 160KVA transformer caused by magnetostriction was calculated at no load under DC magnetic bias, are studied in detail.