Research On Wireless Supplement Technology Of Ultra Capacitor

Non-contact power supply can solve the problems of abrasion,discharge,installation and safety of traditional conductor power supply.It can be used in mobile applications such as trams to avoid the urban landscape impact and contact conductor loss caused by the power supply of the catenary.The super-capacitor has a high power density and can be used as a short-distance vehicle-mounted energy storage.In this paper,super-capacitor is used as non-contact power transmission storage device,and the related issues of energy transmission and control are analyzed through the theoretical and experimental research.The wireless power transmission system of trams is composed of DC input,LC coupled inductor based on the principle of magnetic coupling LC Series resonance,and the four-switch buck-boost circuit as the load-regulating circuit.This paper analyzes the various power links of the wireless electric power system using the space state method to model the small signal analysis of the four-switch buck-boost circuit.The system controls the primary and secondary sides respectively without communication.The primary side circuit adopts the phase shift control method to control the output voltage of the inverter and thus control the current of the primary side winding constant.On the basis of constant current on the primary side,the four-switch buck-boost circuit used in the secondary side to control the charging process.In this paper,a control method of input constant voltage of the power-regulating circuit based on the primary side constant current control is proposed.According to the design requirement,the simulation circuit model is simulated in the MATLAB/SIMULINK simulation software,which verifies the effectiveness of the prototype in the super-capacitor system.The experimental platform of the super-capacitor wireless power transmission system is built.Through a series of experiments,the working mode of the receiving side under the constant current control of the power transmitting primary side is verified,and the relatively optimal steady state operating point and control strategy are obtained.The results of experiments show that the primary side constant current control,the receiving side rectifier output voltage and the inductance current limiting double closed loops and super-capacitor voltage protection control strategy can obtain relatively optimal transmission efficiency.The system can limit the super-capacitor current and protect super-capacitor overcharge.