Research On Outdoor Photovoltaic Power Supply Wireless Charging System For UAV

Unmanned Aerial Vehicle(UAV)has been widely used in power patrol and border patrol,which not only saves the cost of employment,but also ensures the safety of staff.However,the endurance of the UAV is insufficient and the charging conditions in some outdoor areas are limited,which brings great inconvenience to its work.Aiming at the above problems,the wireless charging system of UAV powered by photovoltaic power is studied in this paper,and the main works are as follows:Firstly,the photovoltaic power supply system is studied.Based on the traditional fixed step disturbance observation method,an arctangent variable step disturbance observation method is proposed,which can improve the tracking speed of maximum power point and reduce the power oscillation at the maximum power point simultaneously.The suitable DC-DC converter is selected to realize the voltage conversion and maximum power point tracking of photovoltaic panel,and the DC-DC converter and auxiliary circuit are analyzed and designed.Secondly,in order to realize the constant current and constant voltage segmented charging of lithium battery,a variable parameter CL/LCL compensation network with constant current and constant voltage output characteristics is proposed.Afterwards,the compensation network is combined with the single-tube inverter circuit to form a single-tube variable parameter CL/LCL circuit.The circuit principle,working mode and modeling analysis are carried out.By analyzing the gain of compensation network in circuit constant current and constant voltage mode,the constant current and constant voltage characteristics are proved theoretically.Then,the parameter calculation formula of components in single switch variable parameter CL/LCL circuit are given,and the auxiliary circuit of wireless charging system is designed.The coil and shielding layer of loosely coupled transformer are analyzed and designed,and the magnetic field of loosely coupled transformers with different shielding layers are simulated and compared by finite element simulation software called JMAG.Finally,the photovoltaic power supply system and wireless charging system are simulated and tested respectively.The arctangent variable step disturbance observation method is simulated by MATLAB,and the experimental platform is built,which proves the feasibility and superiority of the control method.The single switch variable parameter CL/LCL circuit is simulated by Saber,and an experimental platform is built to carry out load switching and lithium battery charging experiments,which proves the constant current and constant voltage output characteristics and the feasibility of the single switch variable parameter CL/LCL circuit.