Improved Method of Planar Transformer Winding Loss Based on Two-dimensional Model

Rapid estimation of high frequency winding loss plays an important role in fine design and optimization of planar transformers. The winding loss cannot be obtained by one-dimensional analytical calculation model for planar transformers with cross-structure in horizontal and vertical directions. An improved two-dimensional hybrid calculation model is proposed for the applicability problem. The proposed model calculates winding loss by solving eddy current field and the magnetic field intensity in the vertical direction is taken into account, in which the electromagnetic field boundary value problem is fully expressed with the current density and magnetic field intensity as variables on the basis of the magnetic quasi-static assumption and the two-dimensional assumption. Then, the electromagnetic field boundary value problem is transformed into a linear equation group by the moment method. The coefficient matrix of linear equations established by this method has the advantages of low order and not increasing with the number of split nodes and elements, which achieves the goal of effectively saving the calculation cost under the premise of ensuring certain calculation accuracy. A planar transformer experimental model with 2:2 primary and secondary windings is built to verify the validity of the proposed method. ©2023 Chin.Soc.for Elec.Eng.