Inductive Power Transfer using LLC topology

The portable device industry has been rapidly expanding in the last decade. The charger of the low power portable devices such as mobile phones, notebook, laptop etc. has gained more attention. The power for these portable electronic products is provided by the battery which is frequently rechargeable. However, as technology advances, products are becoming compact and portable and the only parameter that limits the operation of these devices is the battery.In these days, wireless power transfer (WPT) systems are gaining considerable interest owing to the increasing dependence on various battery-powered applications. In this work, a detailed electric ciruit modeling of individual part of the inductive power transfer (IPT) stage is performed. Several DC-AC inverters and output AC-DC rectifiers are examined for WPT systems. Five compensation topologies to improve the power transfer efficiency over large gap are evaluated and their suitable application are identified. Finally, an experimental prototype of "inductive power charger" with nominal power of 5 W is set up to validate advantages of LLC based WPT system.