| With the development of electric vehicles industry,its related charging technology has become one of the research hotspots.The wireless power transmission technology can realize non-contact charging by using the theory of magnetic coupling resonance.According to this feature,this paper combines the charging of electric vehicles with the wireless power transmission technology to realize charging dynamically of electric car.To achieve this goal,this article will study the following aspects:1 Designing a reasonable compensation topology for the transmitting side.The LCC compensation structure is selected on the transmitting coil side to realize the decoupling of the primary side current and the secondary side circuit parameters.Analyzing and verifying the anti-offset characteristics of LCC compensation topology.The transmission power and efficiency of the system are modeled and analyzed,and the optimized transmission power and efficiency and the matching equivalent load impedance are obtained,which provides a theory basis for the configuration of the controller's desired point and the selection of system component parameters.2 The system transmitting coil adopts a distributed laying scheme(the origin of "distributed" in the subject),and designing a reasonable coil structure and arrangement for the distributed dynamic magnetic coupling resonant wireless charging system.The horizontal displacement of the coil will lead to changes in its coupling coefficient.The Maxwell electromagnetic simulation software and the micro-element calculation method are used to optimize the spacing between the transmitting coils and the length of the receiving coils.Based on the complementary ideas,the mutual inductance between two adjacent transmitting coils and receiving coils during motion can compensate each other to reduce the fluctuation range of the total mutual inductance.3 The receiving coil side adopts rectification and DC-DC two-stage control.Introducing the common nonlinear and linear control algorithms briefly,and selecting the appropriate nonlinear control algorithm according to the high frequency switching property of the distributed dynamic magnetic coupling resonant system.The theoretical basis of passive control is introduced and analyzed,and the design process and characteristics of EL model and PCHD model are summarized.The rectification link adopts a double-tube H-bridge topology composed of a diode rectifier circuit and a boost-type chopper circuit.To design the controller for the rectifier circuit,the passive control theory is combined with the method of PI compensation for the desired state value.Modeling and analyzing the rectification system.By controlling the switch of the rectifier,the rectification side can realize the input side power factor correction under the condition of the coupling coefficient change between the coils and stably supply the energy required for the subsequent stage.The DC-DC link adopting a step-up chopper circuit uses a passive control algorithm to mathematically model and analyze the DC chopper nonlinear system,and introduces an output current feedback PI module to update the expected value of the output voltage.Realizing the constant current output of the converter under the fluctuation of the load end within a certain range by controlling its switch.4 The overall design of the vehicle-side controller is proposed.The two-level controller scheme based on the fourth chapter and the SCC controller scheme are proposed.The feasibility of the two schemes is verified and the characteristics of the two are compared and analyzed. |
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