An Orthogonal Decoupled Transformer Design For Inductive Power Transfer Applications

Inductive power transfer (IPT) technology for electric vehicle charging has been widely researched due to its convenient and flexible features. In this paper, an orthogonal decoupled transformer design is proposed to upgrade system power capacity. Two power transmission paths are integrated spatially and decoupled magnetically. An input-parallel output-series (IPOS) circuit topology is employed and circuit analysis is presented. Soft switching of primary inverters can be achieved throughout the allowed misalignment range. The system design and performance are simulated with a 3D finite element modeling (FEM) tool and experimentally verified on a 4 kW prototype with a 210 mm air gap. Experimental results show that the orthogonal structure transformer has good lateral, vertical and axial misalignment performance. The maximum conversion efficiency of the proposed system is 93.6% at full output power and stays above 91.6% throughout the misalignment range.