Efficiency analysis of a Bi-directional DC/DC converter for wireless energy transfer applications

In this study, analysis of a bi-directional half-bridge inverter for wireless power transfer applications is realized. The presented converter topology is explored to reveal the maximum efficiency points with a variable phase shift function between the dual active bridge (DAB) switches. The examination of the converter is provided in terms of variable load and coupling co-efficient factor at a constant switching frequency. A 1 kW contactless system is designed with an output of 100 V by testing the different load conditions at an 8 inch gap between coils. Experimental results indicate that the demonstrated system, which has an average efficiency improvement of 2% with an optimized phase shift between switches, offers higher efficiency in comparison to conventional topologies.