Efficient and High-Power-Density Wireless Power Transfer System Based on Magnetic Integrated S-LCL Compensation Topology

Against the background of certain safety hazards of traditional wired power transmission technology, wireless power transfer (WPT) technology has been widely noticed and applied because of its safety, reliability and flexibility. In WPT systems, compensation topologies are needed on both the primary and secondary sides, and the LCC-S compensation topology is one of the most commonly used compensation topologies because of its superior output characteristics. However, single LCC-S compensation topology often suffer from low output power and transfer efficiency when the battery's equivalent resistance is high, which cannot meet the demand for fast and high power charging of electric vehicles. To address the issue, this paper proposes a magnetic integrated S-LCL compensation topology. It uses fewer passive components and stacks the secondary series compensation inductor and the secondary coil coaxially along the vertical direction. This not only increases the system's power density but also ensures high output power and transfer efficiency when the battery's equivalent resistance is high. This provides a new idea for the constant current-constant voltage (CC-CV) two-stage wireless charging of electric vehicles and has a wide range of application scenarios.