Research On On-board Integrated Charging System And Control Of Electric Vehicle

With the current shortage of fossil fuels and the intensification of social environmental pollution,pure electric vehicles using clean energy and having the advantage of zero emissions have received more and more attention around the world.As one of the most important components of electric vehicles,on-board chargers ensure the energy conversion between the power grid and electric vehicle batteries.Therefore,studying its manufacturing cost,control strategy,safety performance and charging efficiency have important guiding significance for the future development of electric vehicles.Based on this,this paper conducts an in-depth study on the circuit topology and control strategy of the integrated charging system for electric vehicles,which improves the integration and charging efficiency of the electric vehicle charging system,has a variety of working modes and simplifies its corresponding control strategy.First,this paper analyzes the development background of electric vehicles and the structure of the on-board charging system.After studying the on-board charger topology and the technical background and development status of V2G(Vehicle-to-Grid)and V2H(Vehicle-to-Home),designs a circuit topology of an electric vehicle integrated charging system.On this basis,the working principle and energy flow of different circuits in the charging system are analyzed,and different working modes in the system and the corresponding control switch states are introduced.Then,the control strategy of different working modes in the system is studied.In G2V(Grid-to-Vehicle)and V2 G modes,a new overall control strategy based on predictive direct power control of the three-phase PWM rectifier is proposed.The traditional control strategy is improved,and the control strategy of G2V/V2 G mode is simplified and improved the charging and discharging efficiency.For the V2 H mode,in view of the dual PI control strategy of the three-phase PWM rectifier,the PI regulator is used in the dq rotating coordinate system to control the amplitude and frequency of the output single-phase voltage to meet the voltage requirements of the household load.In the T2A(Traction Battery-to-Auxiliary Battery)mode of auxiliary battery charging,bidirectional half-bridge DC/DC converter uses current predictive control instead of current inner loop PI control,which simplifies the battery’s constant voltage and current control strategy and improves the dynamic response speed of battery charging.Finally,the software and hardware of the entire electric vehicle charging system are designed,mainly including the power devices in the main circuit,the control circuit and the DSP software program.On this basis,through the simulation platform of Simulink software and the prototype experiment platform,the integrated charging system and different control strategies are verified in terms of steady-state characteristics and dynamic characteristics.The simulation and experimental results show that the proposed circuit topology and control strategy can complete the corresponding work mode.The paper has 77 pictures,7 tables,and 89 references.