Research on LLC Resonant Converter Based on “Wedge” Shape Flat Winding Transformer

This paper proposes a novel wedge flat winding with thin inside and thick outside improve the current distribution on the flat winding, reduce the loss of transformer. At the same time, as the distance between windings increases, the parasitic capacitance of the transformer will also become smaller. In this paper, the conductivity formulas of two kinds of windings are given first, then the eddy current loss calculation formulas under Dowell model are given, and then the parasitic parameter capacitance model of transformer is given. Finally, Maxwell software was used to simulate the current density distribution, loss and distributed capacitance of the two flat winding for simulation verification. The novel wedge shape flat vertical winding current density distribution is more uniform, and the copper wire utilization rate is higher. At the same time, a 96kHz/ 1152W LLC resonant converter prototype was used to verify the load efficiency of the wedge shape winding under different loads. The efficiency of wedge-shaped flat winding in transformer is higher than that of traditional flat vertical winding, which proves that the performance of the new wedge-shaped winding is better than that of traditional flat winding.