First principles design of coreless power transformers

Abstract

This thesis presents a theoretical foundation and methodology for designing novel 4-coil high frequency coreless power transformers from first principles via lumped equivalent circuit models. The procedure is applied to construct a design for 100W transformer with an S21 parameter value of .96. Using MATLAB and LTspice, simulation tools have been developed to produce accurate predictions of inductance, resistance, coupling coefficients, and S21 parameter values for an ensemble of coil models. These theoretical calculations have been employed for spiral and cylindrical coils and have been validated with numerous constructed experimental designs. The utility uses a first principles approach and derives these calculations directly from the physical parameters and relative positions of the coils. Simulation outputs greatly aid the engineering task of designing an efficient coreless power transformer.