Novel techniques for treating singularity problems in the boundary elementmethod applied to electric field evaluation within the tank of a power transformer

Different shapes of the boundary surfaces within the tank of power transfor mers are classified into flat and round categories. By defining a surface c harge distribution on the surface of the elements, suited in forming each t ype of those surfaces, the governing potential and field intensity equation s are derived. The proposed surface charge distribution functions are such that the continuity of the charge distribution is guaranteed on the boundar ies of the adjacent elements, Then by introducing different techniques, sin gularity problems on the integrands of the elements due to the flat and rou nd surfaces are essentially solved. Fulfillment of these techniques leads t o a quick evaluation of the electric field, Analysis of two typical example s indicates the high accuracy of these techniques. Finally the electric fie ld within the tank of a power transformer Is evaluated, based on the bounda ry element method (BEM) in which the above mentioned techniques have been u sed.