Advances In Planar Transformer Circuit Models: Stray Capacitance Equivalent Circuit for Two and Four Winding Transformers With H-Parameter Network Model

This paper presents a new circuit model of a two-winding and four-winding planar transformers taking into account the capacitive effects between layers. The h-parameters model has been derived for the two-winding transformer which gives theoretical insight on the capacitive effects in a circuit operation. The circuit model suggests three and ten capacitors to model the capacitive effect between a two-winding and a four-winding transformers respectively. Simplified circuit models are also presented that are practically useful in circuit simulations of such transformers. Voltage gain has been determined using both finite element analysis and experimental models. Significant agreement between both were found. The findings of this study support this system model as appropriate tool in the early design of a transformer to perform sensitivity analysis, and to tune the transformer parameters in order to achieve certain design requirements.