A new inductive power transfer topology using direct AC-AC converter with active source current control

Abstract

Generally, in wireless inductive power transfer (IPT) system the power is processed through multiple power transfer stages and this leads to lower efficiency and higher cost of the system. Recent research shows that the use of direct ac-ac converter in IPT system compensates these limitations significantly. However, one of the major challenge of IPT circuit with direct ac-ac converter is to achieve multiple control goals through a single converter. These include load power requirement, maintaining high quality source current and achieving soft-switching of inverter switches etc. In the existing literatures the research is more focused on meeting load power requirement and soft switching of inverter switches. This paper presents a new IPT topology using direct ac-ac converter topology. The control is carried out through conventional two loop method where the outer output voltage loop ensures load requirements and inner loop maintains high quality grid current. Maintaining output power factor of direct ac-ac converter in the lagging side, the ZVS turn on and ZCS turn off of two of the inverter switches are achieved. The detail analysis and design procedure of the converter is presented and experimental results are included to verify the analysis and proposed control.