Evaluation of losses in a secondary-side controlled wireless battery charging system

Abstract

Secondary-side controlled inductive power transfer (IPT) systems are easy to control compared to primaryand dual-side control methods, and more importantly, they do not require wireless communication between primary andsecondary sides. In this paper, a wireless battery charging system based on secondary-side controlled IPT is analyzedand presented in detail. The proposed control method relies on the detection of the secondary coil current and thetransferred power can be fully controlled by the secondary-side active rectifier with reduced number of power switchingdevices. The steady-state performance of the IPT system is evaluated using a fundamental harmonic analysis methodfor resistive and reactive control modes of the active rectifier by taking the converter losses into account. Theoreticaland simulation results of the designed system are validated by experimental results obtained from the implementedlaboratory prototype for charging of a 96-V lead-acid battery.