Efficiency Comparison of Cooperative Inductive Power Transfer Systems

This paper presents the comparison of RF-RF efficiency and load voltage stability between cooperative inductive power transfer (IPT) system using common-coil relay and the one using separated-coil relay. Equivalent circuit technique is used to verify the load voltage stability and evaluate the RF-RF efficiency of the both systems. Electromagnetic simulation results highlighted that the cooperative IPT system using the common-coil relay outperforms the one using separated-coil relay in term of RF-RF efficiency while keeping the load voltages stable against the load variations. Furthermore, the advantage of cooperative IPT system using the common-coil relay over the one using separated-coil relay is still hold even though there is a misalignment of up to 20 percent of the half size of the coils.