On/off Control of Modular Inductive Power Transfer System

This paper explores a planar and modular wireless charger utilizing distributed on/off control. By reconfiguring multiple non-overlapping transmitting (TX) coils to form different charging regions, it requires the examination of the real and reactive power of each module to clarify the cross-coupling effect. The voltage of the compensation capacitor is used as a reference to deactivate modules when the cross-coupling effect becomes significant. Utilizing zero-current detection, the phase information of each module is employed to achieve distributed on/off control, thereby avoid significant cross-coupling effect. This method ensures that each TX operates independently, facilitating the module’s design. In the experiment, a four-TX system is set up to charge a mobile receiver. The effective detection of the capacitor voltage phase enables successful distributed on/off control, resulting in a peak system efficiency of 86%.