Improved design of cover plates of power transformers for lower eddy current losses

Due to the heavy current passing through the steel cover plates of power transformers, some areas are subject to serious local overheating. This affects the safety and reliability of the expensive equipment and power delivery. In this paper, the improved design of cover plates is presented to reduce eddy current losses and to protect them from local overheating. For the accurate calculation of eddy current losses and power loss density distribution in the cover plates, the indirect BIEM (boundary integral equation method) is applied to the 3D open boundary problem caused by the heavy current of leads in a three-phase power transformer. The numerical results by the indirect BIEM are compared with experimental values