High-frequency displacement current transformer with just one winding

Abstract

Purpose This paper aims to describe a new concept of transformer based on the displacement current. The paper shows how this idea can be translated into reality and presents an example of a working design. Design/methodology/approach The authors replace the primary winding of the transformer with a capacitor. The displacement current between the capacitor plates induces a magnetic flux in the core. This flux in turn induces electromotive force in the classical secondary winding. Findings The basic mathematical aspects illustrated by results obtained from a simulation developed using a commercial software ANSYS-HFSS are given. The saturation of the magnetic core due to the applied high-frequency range is investigated and simulated using a finite difference time domain code implemented in MATLAB. A prototype transformer was built and tested; the obtained results confirm the previous ones from simulations. Originality/value A new concept of the single winding transformer was used as a pulse forming circuit.

Analysis of the Distributions of Displacement and Eddy Currents in the Ferrite Core of an Electromagnetic Transducer Using the 2D Approach of the Edge Element Method and the Harmonic Balance Method

“…By increasing the frequency of the source, the designers have been able to develop new types of electromagnetic converters that operate with frequencies reaching tens or hundreds of kilohertz (kHz), such as medium-and high-frequency transformers operating in Dual Active Bridge (DAB) systems, as well as systems that are already capable of operating at frequencies up to tens of megahertz (MHz), i.e., Wireless Power Transmission (WTP) systems [5][6][7]. Currently, a few attempts can be observed to develop electromagnetic converters, of which the operation is based on the use of not only the conductivity currents but also the dielectric displacement currents, for example the high-frequency capacitive-inductive transformer developed by the team of Prof. J. Starzyński from the Military University of Technology in Warsaw [8].…”