Research On Output Characteristics Of Wireless Charging Compensationg Network For Electric Vehicles

In order to reduce the shortage of oil resources and serious environmental pollution,the development of new energy vehicles has become the country to achieve sustainable development,energy saving and independent innovation of the strategic needs.For electric vehicles to market challenges,electric car charging has become the key to the future development of new energy vehicles.At present,the electric car charging is mainly centralized power station,distributed charging pile and other traditional contact charging method.As a new type of charging method for new energy vehicles,radio energy transmission technology has the advantages of flexibility,safety and reliability,and has attracted more and more attention.It has a good prospect of market application and brings new developing opportunity to electric vehicles.Based on the principle of inductively coupled wireless power transmission,this paper makes a theoretical study on the characteristics of wireless charging compensation topology circuit and carries on the corresponding experimental analysis.The paper mainly studies from the following aspects:First of all,this paper introduces the background and significance of the research,analyzes and compares the current realization methods of electric energy transmission technology of electric vehicles,and summarizes the existing problems of electric charging of electric vehicles according to the present research situation at home and abroad.Secondly,it analyzes the output current,voltage gain and the equivalent impedance characteristic of S-LCC and LCL-S composite compensation topology,which are four basic compensation topologies of wireless power transmission circuit.Based on the battery load characteristics,the battery charging method is analyzed,the battery model is built,the SP-SSP hybrid compensation topology is proposed,and the constant current constant voltage output principle is analyzed.The simulation can be applied to the electric vehicle battery Constant current constant voltage charging.Then,the transmission power and efficiency expression of SP and S-SP compensation circuit are deduced.The effects of resonant converter operating frequency,equivalent load,mutual inductance and transmission distance on the transmission power and efficiency of SP and S-SP compensation circuit are analyzed.The wireless charging circuit is designed to support the design of the wireless charging circuit.The sensitivity of the resonant capacitor parameters is analyzed,which provides the theoretical guidance for the configuration of the resonant capacitor.Based on the analysis of the circuit efficiency,the efficiency of the S-SP compensation circuit is optimized by using the efficiency product method,which makes the transmission power and efficiency of the wireless charging circuit reach the global optimal design.In order to improve the transmission power and efficiency of the wireless coupling circuit of the electric vehicle reference.Finally,the magnetic coupling transformer is built and the hardware experiment platform is built.The characteristics of S-P and S-SP compensation circuit are analyzed experimentally.In the loosely coupled transformer primary and secondary spacing 100 mm under the conditions,through the secondary equivalent load mutation test can be seen SP,S-SP compensation circuit can achieve constant current,constant voltage output,analysis circuit transmission power and efficiency with the equivalent load changes The feasibility of the theoretical simulation analysis of circuit performance characteristics is verified by experiments.