First Principles Design of Coreless Power Transformers
By Angel J. Carvajal Submitted to the Department of Electrical Engineering and Computer Science February 2, 2018 in Partial Fulfillment of the Requirements for the Degree of Master of Engineering in Electrical Engineering and Computer Science.
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 𝑆"# parameter value of .96. Using MATLAB and LTspice, simulation tools have been developed to produce accurate predictions of inductance, resistance, coupling coefficients, and 𝑆"# 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. Thesis Supervisor: Dr. Chathan M. Cooke Title: Principle Research Engineer, RLE