Fabrication Tradeoff Based Optimal Synthesis of Winding Configurations for Planar Transformer in CLLC DC–DC Converter

Adhering to the objective of modeling and selecting the most optimal winding configuration for a high-frequency planar transformer (HFPT) for auxiliary charging systems for more electric aircrafts, this article elucidates numerous fabrication and design-based constraints and correlations to enable parametric modeling of various magnetic components. Instead of providing generalized solutions, this article thoroughly characterizes all possible winding configurations for HFPT employed in a bidirectional
CLLC
dc/dc converter. A detailed analytical study is presented for each component and verified using several instances of three-dimensional finite-element analysis based model to synthesize the effective field and current density distribution in the windings. Several design-based tradeoffs are graphically explained with various criteria pertaining to optimal winding selection to study the interdependence of the resultant parameters on hardware specifications, such as the printed circuit board (PCB) thickness and its fabrication layout, air gaps, and conductor thickness. The article presents a comprehensive comparison between the analytical, simulation, and experimental analysis that portrays a strong agreement between these models with an average mismatch of up to 6.2%. An experimental prototype of
CLLC
converter rated for 1 kW nominal power, operating at 500 kHz resonant frequency, is developed with the optimal HFPT characteristics that yields a peak efficiency of 98.49% with magnetics stage efficiency of 99.31%.