| Compared with wired charging,wireless charging technology has been widely used in many fields in recent years due to its advantages of better security and convenience.However,wireless charging technology also faces the problems of low efficiency of charging system and poor quality of charging voltage and current,which are the key problems restricting its development.Based on the application of autonomous underwater vehicle(AUV)wireless charging,the influence of each part on the system efficiency and output voltage and current is studied from the aspects of resonant compensation network,secondary side topology and its control,magnetic coupling mechanism design,and optimizes their design,designs and manufactures an efficient wireless charging system for AUV in the paper.Firstly,starting from the resonant compensation network of wireless charging system,four basic resonance compensation networks are analyzed by loosely coupled transformer mutual inductance model,and the advantages and disadvantages of each compensation network are summarized and compared.The resonant stability,input and output characteristics,output power and efficiency variation characteristics of SS and LCC-S compensation networks are further studied.After comparative analysis,LCC-S resonant compensation network is determined for this application.Then,aiming at the loss and control problem of the side circuit,the topology and control strategy of the secondary side circuit are studied and optimized.Common battery charging strategies are analyzed and the constant current and constant voltage charging method is determined.The working principle of synchronous rectification and interleaved Buck circuit is analyzed,and introduced into the secondary side circuit.The secondary side circuit of the full-bridge synchronous rectification and interleaved synchronous rectification Buck cascade is designed.The principle of two control methods of full-bridge synchronous rectification is analyzed,and the control scheme of drain-source voltage detection method is designed.The small signal analysis of the interleaved Buck circuit is carried out,and the transfer function of the circuit is obtained.Then the control parts under constant current and constant voltage modes are designed respectively.Then,the hardware circuit of the secondary side is designed,and the switching tubes and other devices of the main circuit are calculated and selected.The control circuits such as driving circuit,sampling circuit and protection circuit are designed.The magnetic circuit model of the magnetic coupling mechanism is established,and the factors affecting the coupling coefficient are analyzed.The finite element analysis tool is used to design the magnetic coupling mechanism.The magnetic coupling mechanism used in AUV is made,and the experiment of rotating dislocation and axial dislocation is carried out.In the range of ±30° rotating dislocation,the change of coupling coefficient is less than 0.05,and in the range of ±10 mm axial dislocation,the change of coupling coefficient is less than 0.06.Finally,LCC-S resonant compensation network,full-bridge synchronous rectification circuit and interleaved synchronous rectification Buck circuit are established by MATLAB/Simulink,and the system simulation is carried out to verify the functions of each part.The experimental platform of wireless charging system is built to verify the effect of the design on system efficiency and output voltage and current quality.There are 78 figures,7 tables and 66 references in this thesis. |
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