Articles techniques et présentations

Transformers, as any other industrial products, have to comply with various requirements on noise levels. Three main sources of noise can be identified in transformers: no-load noise or core noise generated by magnetostriction in the core steel laminations, load noise produced by electromagnetic forces in the windings and noise due to auxiliary equipment such as fans and pumps used in the cooling system. The paper will focus on load noise which is a typical multiphysics mechanism involving electromagnetics, mechanics and acoustics. The finite element model coupling the different physical fields has been developed by using COMSOL. Some simplifications have been introduced to reduce problem size and computing time. The prediction model provides a relatively fast and rather accurate tool to perform parametric studies. In the paper, the prediction tool is used to investigate the effects of various materials and geometrical parameters on the sound levels.