Abstract
In order to meet people's pursuit of higher efficiency of power electronic equipment, reducing the winding loss of planar transformer is an important part. Due to the simplicity of the calculation method, the current method used to evaluate the winding loss in the industry mainly is the one-dimensional Dowell model, but with the increase of the operating frequency, the influence of the edge effect caused by the gap between the winding and the core becomes non-negligible, which will affect the calculation accuracy of the Dowell model and lead to the increase of the winding loss. Therefore, the influence of edge effects should be paid attention to when evaluating winding losses, and edge effects should be considered when designing windings to reduce winding losses. In addition, when the air gap avoidance is used to reduce the winding loss in the planar flyback transformer, the winding loss may increase instead of decreasing, and the reasons for this phenomenon are analyzed and an improvement method is proposed, and finally the correctness is verified by simulation.