Structure Design of Planar Transformer Winding

In order to reduce the volume of the magnetic component, the operating frequency of the magnetic component is generally increased. However, as the operating frequency increases, skin and proximity effects will increase the winding losses. At the same time, in the low-voltage and high-current DC/DC power supply module, method of parallel winding usually be used to increase the current carrying capacity of the winding. But the skin and proximity effects will lead to the unevenly distribute of parallel winding current, resulting in a higher AC resistance. In this paper, by using the orthogonality between the skin and the proximity effect, it is concluded that the cross-transposition technique can reduce the winding loss, and the symmetric cancellation principle is used to derive the arrangement of the current parallel division of the secondary parallel winding in the turns ratio of n:1.method. Finally, the effectiveness of the current equalization method of the secondary parallel winding of the planar transformer is verified by Maxwell 3D.