| The proposal of “Dual Carbon” promotes the process of energy reform.Road transportation is one of the important carbon emission sources and has become a key field of energy reform.The replacement of conventional fuel vehicles by low-emission electric vehicles has become an inevitable trend in the industry,but its development has been hampered by stopover charging and high battery costs.Electric Vehicle Dynamic Wireless Charging(EV-DWC)technology enables a new type of charging that can effectively reduce the cost of onboard batteries and increase vehicle range.The Magnetic coupler is a key part of EV-DWC system,which determines energy efficiency characteristics.Therefore,it is necessary to study the structure design and parameter optimization of the magnetic coupler.At present,the research on the design method and parameter optimization strategy of the magnetic coupler is insufficient.The design process fails to form a unified standard,resulting in the implementation of the EV-DWC system usually carried out by manual experience,which limits the process of its practicality and industrialization to a certain extent.Based on the above problems,this paper focuses on the design and optimization of the magnetic coupler for the EV-DWC system.Especially the power fluctuation problem of the piecewise magnetic coupler is designed and optimized from the magnetic circuit and electric circuit.The specific work is as follows:(1)Research on power fluctuation principles of sectional track-based EV-DWC system.Firstly,the mutual inductance calculation model of the piecewise magnetic coupler was established in the magnetic circuit,and the mutual inductance fluctuation law was obtained under the condition of the receiver moving.Secondly,the constant voltage and constant current characteristics of the port and the realization conditions of the compensation topology were compared and analyzed based on the two-port theory.Based on the above,the power fluctuation model of the sectional track-based EV-DWC system was established by combining field and circuit,and the key parameters affecting the system output power were obtained.Finally,the idea of power fluctuation suppression was expounded from magnetic circuit control and electric circuit control,which provides theoretical support for the design and optimization of the magnetic coupler.(2)A method for designing magnetic coupler of sectional track-based EV-DWC system was proposed.Firstly,in terms of magnetic circuit design,the SAE J2954 standard was adopted in the design of receiving coil considering the mechanical structure of the vehicle chassis and compatibility with the static wireless charging system,and design standards were proposed for the coil winding,size design and wire selection of the transmitter coil.Secondly,in circuit design,the energy transfer characteristics of eight common compensation topology types under system parameter fluctuation were compared and analyzed.It is concluded that the higher-order compensation topology has more advantages than the lower in terms of input current adjustment,power stability and anti-harmonic deflection ability.Furthermore,the design evaluation standard of the coupler was established from the calculation of electrical stress,loss,antideviation and electromagnetic compatibility,and the design evaluation system of the coupler was improved.Finally,the design flow of the sectional track-based magnetic coupler was defined,which solves the problems of unclear magnetic coupling design flow and difficult magnetic circuit integration design.(3)An optimization method for magnetic coupler of sectional track-based EV-DWC system was proposed.Firstly,in the aspect of magnetic circuit optimization,aiming at the problem of large mutual inductance fluctuation of single transmitter and single receiver topology,a coupling mechanism based on multi-transmitter and single receiver topology was proposed,and the necessary conditions of mutual inductance stability during switching were proposed.The number of transmitter coils,dimension,optimum spacing and optimum switching point were optimized to solve the mutual inductance fluctuation problem,which was verified by simulation and experiment.In the aspect of circuit optimization,an improved Hybrid Particle Swarm Optimization(HPSO)algorithm was proposed to solve the nonlinear optimization problem of high-order compensation circuits.The simulation result shows that the HPSO algorithm has better global convergence,and the designed circuit parameters meet the requirements of electrical stress under mutual inductance fluctuation and frequency offset. |
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