Investigation On UAV Hovering Wireless Charging Method Based On Wireless Power Transmission Technology

Unmanned Aerial Vehicle(UAV) is an aircraft controlled by wireless radio or pre-installed programs which can be equipped with various facilities and fulfill different tasks. It has been widely used in many areas because of its favorable advantages such as simple structure, small size, lower cost, high survival rate, flexibility and adaptability. However, its endurance, flexibility and accessibility have always been restricted as a result of the limit of current accumulator and charging techniques. Therefore, to promote the development of UAV, it’s necessary and urgent to solve the problem of how to recharge UAV in the air conveniently. In order to shed some light on the solution, this paper tries to apply wireless power transfer technology to the charging technique of UAV and has designed a wireless power transfer system based on the theory of magnetic resonance. To reduce the power consumption of coupling mechanism, this paper has proposed a constant-frequency control strategy to increase the efficiency of the wireless power transfer system.The main structure of this paper can be divided into the following five parts:Part 1 analyzes the current endurance of UAV, which is limited by traditional power transfer technique and accumulator, introduces some commonly-used approaches to charging UAV, and puts forward the application of wireless power transfer technology to the power supply technique of UAV.Part 2 mainly focuses on introduction and comparison of several main-stream wireless power transfer techniques, and discusses the theory of near-field coupling and mutual inductance coupling, which provides the foundation for the features of the power transfer system used on UAV: loose coupling, dynamic mutual inductance and dynamic load.Part 3 studies the how to transfer power efficiently under the circumstance of loose coupling, and then proposes a wireless power transfer system with a power transfer model based on the theory of magnetic resonance and PSSS coupling topological structure. After that, this chapter has analyzed and optimized the characteristics of the proposed system based on the condition of dynamic mutual inductance and dynamic load.In order to solve the problem of mistuning of the resonant network for the changes of mutual inductance and load under the circumstance of constant-frequency control, part 4 puts forward the strategy of constant-frequency control based on dynamic resonance and has introduced the working principles, the design of tuning branches and the way of constant-frequency control in details. At last, there is a simulation study based on the model proposed by Simulink.The last part is the construction of the hardware of the experiment and the study of results in the experiment of the proposed wireless power transfer system.