Single Switch Multi-Winding Wireless Power Transfer System Based on Z-Source Network

Nowadays the number of portable battery powered devices that requires frequent charging are rapidly growing worldwide. The main advantage for customers of wireless charging of such devices is ease of use and due to this reason wireless chargers are becoming more and more popular. To be able to charge devices from different vendors with one charging device introductions of standards for wireless power transfer is very important. Nowadays more common used standard is Qi, due to several limitations the increase of charging power is hard to increase. One of possible solution to increase the transferred power is to develop new power electronics converter topologies. In the paper it is proposed a new idea how by using Qi compliant coils transfer power to the receiver with modified power converter topology and coil position. The paper describes new inductive power transfer approach based on Z-source network tuned in resonant mode. The proposed topology allows reduce number of semiconductors, additional losses associated with non-sinusoidal signals can be reduced by further modification of the circuit. Theoretical justification along with simulation and experimental verification are presented in the paper.