Comparative study of multicore planar transformers on printed circuit boards

Abstract

Three potential options to implement multicore planar transformers using a printed circuit board as windings are presented. The first option utilises a distributed transformer configuration where smaller transformer elements with separate cores are interconnected to function as a single transformer. The second option has a lumped core configuration which uses multiple cores arranged to function as a monolithic core while the third is a hybrid of the first two configurations. The three transformers were designed for a 400/40 V, 1 kW, DC-DC converter application at a switching frequency of 100 kHz. The electrical and thermal characteristics of the three configurations are compared using finite-element analysis of the electromagnetic fields. The simulation results are also validated by measuring the electrical characteristics of transformers fabricated in the three configurations. The electrical and thermal characteristics of the transformers are also verified in a power converter system. Results of the comparison show that the distributed core configuration gave the best thermal characteristic while the lumped core configuration has the least winding losses.

Printed Circuit Boards: The Layers’ Functions for Electronic and Biomedical Engineering

“…Low-cost, coreless, PCB-based transformers for signal and low-power applications have been proposed [ 55 ]. Regarding the use of the core, there are other developments [ 56 , 57 ], but additional materials are required, typically ferrite. In addition, these two last developments use a multiple-PCB structure to fabricate the transformers.…”

Automated tool for 3D planar magnetic temperature modelling: application to EE and E/PLT core‐based components

“…Regarding planar magnetics, the component's temperature rise can be evaluated during the design stage with the equivalent thermal resistance [11][12][13]. Some expressions of such thermal resistance for planar magnetic cores are given in literature [14][15][16][17][18].…”