Magnetic and Noise Characteristic in Joints Regions of Transformer Lamination Cores with Magnetorheological Materials

The audible noise is one of the main environmental issues that the highly industrialized world have to face with. The noise generated at the joint regions of transformer cores is mainly due to the magnetostrictive strain in silicon steel cores and the electromagnetic force exerted from leakage magnetic field among laminated cores. In order to reduce the noise, this paper proposes a novel method by filling one kind of magnetorheologial material into the air gap at joint regions. The effectiveness of this way is investigated by means of numerical simulation of a transformer core model with simple lap joints. The numerical simulation is carried out by a multi-physics coupling analysis. The study provides an effective way to reduce the vibration and noise of power transformers.