Research And Design Of Wireless Charging Efficiency Optimization For UAVs

With the civilization process of Unmanned aerial vehicles(UAV)advancing,UAVs have been widely used and promoted in daily production and life.As an emerging charging method,wireless charging technology has its advantages of high safety and convenience,and the application of wireless charging technology to UAVs has a broad development future.However,wireless charging technology for UAVs faces many challenges in practical application,the most critical issue being the improvement of charging efficiency.The research in this paper focuses on the UAV wireless charging system with the compensation topology as the primary research content as follows:The transmission characteristics of the four basic resonant compensation topologies are analyzed,the mathematical modeling analysis of the commonly used LCC-S topology is performed,and the effects of load resistance and coil mutual inductance on their efficiency transmission are analyzed.For the problem that the LCC-S topology has difficulty in maintaining high transmission efficiency in the pre-constant current charging period,i.e.,at high current and low equivalent load,an improved LCC-S topology with the addition of a planar transformer is proposed.The paper conducts mathematical modeling and analysis for the improved LCC-S topology,derives its efficiency expression,and analyzes the factors affecting the transmission efficiency of the improved LCC-S topology,such as coil mutual inductance,equivalent resistance,and transformer parameters to obtain the planar transformer design parameters in this wireless charging system,and uses the transformer parameters such as excitation inductance value,primary and secondary turns ratio,and operating frequency as the design basis,combined with Maxwell simulation software is used to design a planar transformer suitable for the wireless charging system.The LCC-S topology and the modified LCC-S topology simulation system are built for verification.In the test conducted on the UAV wireless charging system with a power level of 1KW,when the load resistance is 1Ω,the energy transfer efficiency of the improved LCC-S topology is 78.9%,while the energy transfer efficiency of the LCC-S topology is 59.3%,and when the equivalent load reaches 2.4Ω,the energy transfer efficiency of the improved LCC-S topology is 84.4%,and the energy transfer efficiency of the LCC-S topology is 82.9%,the transmission efficiency of the enhanced LCC-S topology is better than that of the LCC-S overall at low equivalent loads.