Design And Optimization Of Coils In Wireless Power Transfer For EV Charging

By the progress of electronic equipment,wireless power transmission technology,featuring convenience,safety and reliability,has become a hot topic and is to be a replacement of the plug-in charging technology.Compared with traditional conductors,wireless power transmission technology(WPT)could transfer powerthrough long distance validly.Above all the WPTs,inductive power transmission technology(IPT)has developed for a long time on theoretical and practical basis.It is currently the most widely used and the most suitable technology for vehicles charging.The present study mainly focuses on the research and optimization of magnetic coupling coils on IPT systems.Firstly,thisthesis outlines eight topologies for inductive wireless power transfer.The study expounds the characteristic of different kinds of topologies through the mathematical deduction,and elucidates that the topology using capacitor serial-serial compensation and current source is suitable for electric vehicle charging.Thesuccedent simulated results show perfect agreement with theoretical analysis.Based on the above-work,this thesis proposes a wireless power transfer systems with immittance converter resonant network.The study analyzes theconversion from voltage source to current source theoretically,devises an overall mathematical model of the immittance converter,and verifies the practicability of LCL immittance converter.Also,this thesis makes an attempt to optimize the coils for wireless power transfer.The study analyzes the principle of electromagnetic shielding and the principle of material selection,and develops inclusively simulation procedure for magnetic coupling coils optimization.The advantages and disadvantages of circular coils and DD coilsare evaluated and compared in order to provide higher deviation tolerance and transmission power.In addition,this thesis buildsan LCL-SS resonant network experiment platform,produces a set of mobile wireless power transmission system inorder to ensure the invention meets the practical requirements,performs test on two different types ofmagnetic coupling coils to prove previousanalysis,and constructs a 3kW wireless power transmission system test platform using optimized DD coils.Finally,the thesissummaries contents of this research,propounds possibility for improvement and provides a reference for future research.