Research On Constant Output Switching Wireless Charging System Based On Frustum-shaped Magnetic Structure

In the field of drone charging,the wireless charging platform has gradually become the focus of research.The drone may have an offset when it is on the wireless charging platform,which will bring a reduction in charging power and efficiency;battery charging requires constant current,and then constitutes constant voltage,therefore requires the system to be implemented constant current output and constant voltage output.For the above two points,this paper proposes a constant output switching wireless charging system based on a circular stage magnetic coupling structure.The system has both a certain anti-offset capability,and can achieve constant current / constant voltage output of the system at different frequencies.Real-time switching control is performed according to the change in the load state.A new type of round counter magnetic coupling mechanism is proposed according to the background of the drone wireless charging.The designed magnetic coupling mechanism has a certain anti-offset performance and a higher coupling coefficient.Due to the large number of parameters of this magnetic coupling mechanism,the parameters are optimized by the finite element simulation software by means of the control variable.Finally,through comparison with traditional structures,verification of design and optimization,and exhibit excellent characteristics of the magnetic coupling mechanism.The new S-SP compensation topology is used according to the desired round counter-shaped magnetic coupling structure and the system,and the need for constant current and constant voltage output is required.This topology only requires three compensation devices to achieve constant current / constant voltage output at two frequencies.First,the compensation topology is fully analyzed,and the leakage equivalent model and basic resonance circuit of the loosely coupled transformer can be used to achieve constant current / constant voltage output,and the current /voltage gain is given;then the topology is then resistant to the topology Analysis of frequency characteristics of analysis,harmonic analysis,stress analysis,and voltage current,verify the excellent comprehensive performance of the topology.In order to complete the segmentation of the system constant current / constant voltage,the system switching control strategy of the primary side detection and primary side control is proposed.A parameter design method is proposed for complexity of WPT systems.According to the relationship between the input impedance and the load impedance,it is found to detect the method of the secondary equivalent load state in the original side,and thereby proposes a system frequency frequency switching control policy based on the battery charging equivalent model,so that the system can detect the sub-detection Side equivalent load status,and timely switching control.Finally,the prototype experimental verification,set the input voltage 48 V,constant current frequency 66 k Hz,constant current output 2A;constant voltage frequency 107.5 k Hz,constant voltage output 21V;moderate system efficiency up to87.1% of the prototype,and can be used according to load conditions Switch.Under the premise of ensuring the efficiency,this drone wireless charging platform can complete the entire charging process for the drone.