| Abstract |
The novel construction of the modular concentric transformer for power electronics is described and
analyzed in the paper. Proposed design of the transformer is dedicated for high frequency (the best
results are in the range of 500 kHz to 3 MHz). The transformer has two windings made of
concentrically arranged, thin-walled pipes, formed as a multi-turn spiral and put into magnetic core.
The primary (inner) turns are connected in series and secondary (outer) ones are connected in parallel.
The transformer described in the paper has turn-to-turn ratio 2:1, but in general the turn ratio can be
different. The transformer is of high efficiency (above 98%) and very high ratio of windings coupling
(about 0.998). High power density (above 100 kW/kg) for output power about 5 kW is its additional
advantage. The paper is focused on influence of the shape and arrangement of the windings and
magnetic core on the transformer properties. The results of analysis (efficiency, output power and
power density) determine optimal design of transformer with respect of relevant transformer
parameters. The analysis is based on FEM and is carried out using ANSYS software. The selected
results of FEM analysis (in particular parameters of the equivalent circuit of the transformer) are
compared with the results of the laboratory measurements. |
