Research On Wireless Power Supply Technology For Moving Objects Based On Capacitive Coupling

Capacitive Power Transfer(CPT)technology as a new type of wireless power supply technology has been deeply studied in modern times.Compared with Inductively Power Transfer(IPT)systems,CPT systems generally do not produce eddy current losses in the surrounding conductors,and are more efficient;using metal plates as coupling parts,the structure is simple and the cost is low.The CPT system uses high-frequency alternating electric fields of coupling capacitance between metal plates to transmit energy.The general wired power supply method is often used for stationary electrical equipment,and for moving electrical equipment,the wired power supply method is inferior to wireless power transmission in terms of flexibility,safety,and reliability.The CPT technology can not only complete the energy supply to mobile electrical equipment,but also have higher efficiency and power.In the future,it has better development prospects in the energy supply of mobile electrical equipment.This article first describes the research background and current domestic and international research status of the moving object capacitive wireless energy transmission technology,as well as the development trend of the moving object capacitive wireless energy transmission direction at home and abroad.Then the coupling mechanism part of the system is introduced,the model of the capacitive coupling mechanism of the CPT system is established,and the Comsol finite element simulation software is used.The influence of the metal plate area,distance and position on the coupling capacitance is studied,and the corresponding equivalent circuit model is finally established.Based on this circuit model,the CPT system is simulated and analyzed,and the circuit model is verified by physical experiments.The bridge inverter circuit used in the traditional CPT system is difficult to control at a high frequency.Therefore,by comparing the advantages and disadvantages of various high-frequency transmitter converters,this paper chooses a single-switch DC-DC converter as the transmitter-side converter.Modeled the single-switch CPT system,analyzed the working state of the system,deduced the voltage and current formulas in different working modes,obtained the parameters of various components through theoretical analysis and experimental optimization,and carried out simulation analysis and experimental verification;Research and analysis of the system soft switching and parameter optimization work.For the CPT system,a metal plate coupling capacitor is introduced into the circuit,and an LC compensation network is introduced in order to compensate the coupling capacitor.The fourth part is the characteristics of the LC compensation network of the CPT system.Modeling the LC compensation network,detailed analysis of the system frequency splitting phenomenon and symmetry and asymmetry.The above coupling capacitance model and the LC compensation network are simulated using LTspice circuit simulation software to obtain the input and output characteristics of the LC compensation network.As well as comparing the design of various rectification networks,choose a half-wave rectification network with better performance.Combined with the above research on coupling capacitance,a complete CPT system based on LC compensation for single-switch DC-DC converter is obtained.Finally,design and produce a single-switch DC-DC inverter power supply,design and produce moving objects,complete the construction of the CPT experimental platform,and realize the capacitive wireless energy supply to the moving objects.