Design of an IPT Battery Charger with Configurable Constant Current and Constant Voltage Outputs

Abstract

The inductive power transfer (IPT) technology has gained a wide acceptance in battery charging applications due to its significant advantages over traditional plug-in systems. It is desirable that an IPT charger can be configured with the initial constant current (CC) and the subsequent constant voltage (CV) outputs as the battery requires, combating constr-aints of the loosely coupled transformer (LCT) parameters without sophisticated control schemes. Meanwhile, a near resistive input impedance and soft switching for the whole battery charging process can be permitted. To meet these requirements, this paper systematically analyzes the characteri-stics of some existing compensation topologies and proposes two hybrid IPT structures to realize the configurable CC and CV outputs in regardless of the constraints of LCT parameters. Due to the different output filters, a hybrid IPT battery charger, actually using the combination of the doublesided LCC and LCC-S compensation circuits, is proposed and implemented in this paper. Finally, an experimental prototype is built to validate the proposed design.