Design and Implementation of a Full-Bridge LLC Converter With Wireless Power Transfer for Dual Mode Output Load

Abstract

The proposed research is to accomplish a converter for driving DC load or AC load with wireless power transfer (WPT) technique. In this novel scheme, a full-bridge LLC resonant converter is adopted to deliver the energy from the primary to the secondary side. Besides, the LLC converter has soft-switching characteristic of the switches at the primary to improve the efficiency of the converter if the switching frequency is selected appropriately. In order to achieve the feature of wireless power transfer, the WPT (transmitting/receiving) coils are utilized to replace the transformer. The leakage inductor can be treated as a resonant inductor integrated in the transmitting coil. In the output side, a sinusoidal pulse width modulation (SPWM) technique is added to generate AC voltage for specific load. In other words, the proposed converter can output DC or AC voltage by user’s demand. In the end of this research, a LLC converter with WPT technique for 1kW is implemented. The experimental results and the related waveforms are also shown in the content. In this topology, the highest efficiency of DC output is 89.2%, and the highest efficiency of AC output is 82.6% respectively.