Evaluation of H-bridge and half-bridge resonant converters in capacitive-coupled wireless charging

This paper compares two main topologies used for capacitive-coupled consumer wireless charging which has several advantages over inductive coupling including lower cost and no shielding requirements. There has been minimal data in the literature on preferred transmitter topologies. Two types of transmission systems are compared in simulations and experiments. An experimental charging system was built and tested with the evaluation of efficiency of h-bridge and half bridge transmitters. Preliminary experimental results indicate that the h-bridge is both economically and efficiency-wise advantageous over the half bridge in this application. The overall results show that the H-bridge is more efficient even though it has more semiconductor switching devices causing it to have a slightly higher cost. Immediate future work is implementation of closed-loop control for receiver-side voltage regulation.