Configuration and Control Design of Inductive Power Transfer Systems With Back-End Power Factor Correction

Wireless inductive power transfer (IPT) converters have gained significant traction in grid-connected applications owing to their inherent safety and user-friendly features. Unlike conventional setups employing intricate multiple-converter-stage IPT configurations involving both a front-end converter for power factor correction (PFC) and a back-end converter for power regulation, our approach integrates both PFC and power regulation functions solely within the back-end converter. This streamlined design eliminates the necessity for an additional front-end converter, thereby yielding a more straightforward and cost-effective system. This article delves into the investigation of the circuit configuration principle, specifically the incorporation of the filter circuit of IPT converter and the back-end converter, aiming to reduce the component counts. To achieve the dual objectives of PFC and rapid power regulation, a dual-loop control scheme tailored for a back-end PFC IPT system is developed. The derivation of small-signal transfer functions serves as a crucial aid in setting optimal control parameters, and a comprehensive control stability analysis is presented. A 1.2-kW experimental prototype is built to validate the performance of PFC and the fast power regulation of the proposed back-end PFC IPT system.