Design and Optimization of a Wireless Power Transfer System with a High Voltage Transfer Ratio

With the development of the logistics industry, low-voltage systems, such as intelligent logistics vehicles, have also started to propose application scenarios for wireless power transfer systems. As most logistics vehicles use lithium batteries for energy supply, the wireless charging system has to adapt to the charging characteristic curve of lithium batteries. In this paper, a dual-transmitter single-receiver compound resonant compensation topology with a high voltage ratio is proposed, and a corresponding magnetic coupler is designed and optimized through finite element analysis, which guarantees adaptive output curves according to the working state. A 1 kW experimental platform is established to verify the theoretical analysis, which realizes a high voltage transformation ratio with 90.3% efficiency. Throughout the whole charging process, the output curve agrees with the charging profile of the lithium battery, which can greatly extend the service life of lithium batteries.