Experimental comparison of planar transformer architectures for half-bridge resonant topology

Abstract

Power electronics is experiencing a strong growth, driven by industrial demand for applications as diverse as wall adapters and renewable energy. In addition to topologies, semiconductors or control, there is also a need for research in magnetics, such as planar transformers, which are very useful for certain applications where a low converter profile is desired, so that replacing traditional wire transformers has a quantitative advantage in terms of power density and geometry, as well as EMI reduction. In this paper, an experimental comparison of different planar transformer architectures is made, a contrast of the test results is presented. Six possibilities are carried out, dealing with diverse configurations in primary and secondary windings, of which a theoretical estimation of losses is performed. To demonstrate the effect of variations in the proposals, a 100 W prototype converter, with an input voltage range of 320 to 380 V and an output range of 5 to 20 V is developed based on the novel hybrid flyback topology, reaching a maximum efficiency of 97% using GaN semiconductors. With it, a comparison is made in terms of efficiency and common noise between the alternatives.