A Control Strategy For The PHEV Two-way Charging And Discharging Device That Based On The V2G Technology

Research and development of energy-efficient and green cars is veryimportant to achieve the sustainable development of human society andresolve the contradiction between the continuous development of theautomotive industry and its environmental pollution and energy crisis. Theplug-in hybrid electric vehicle (PHEV) has the advantages of both thetraditional hybrid electric vehicles and pure electric vehicles as a brand newcar. Currently, the bi-directional charging and discharging device(PHEV)based on the car electrical interconnection (V2G) technology is the best choiceto make car users, the grid and automotive manufacturers to obtain benefitstogether. Additionally, it can reduce the threat of environmental pollution andenergy crisis. The main contents of this dissertation are as follows:Firstly, PHEV and V2G technology’s development and advantages areintroduced. Then the importance and necessity of the PHEV charging anddischarging device are pointed out. Sequently, schematic and block diagramsof the bi-directional flow of energy between electric vehicles are given andobviously the PWM rectifier and DC/DC make the electric energy exchangebetween the grid and the electric vehicle.Secondly, the theory, control strategy and mathematical models of thethree-phase(VSR)voltage rectifier are analyzed and the vector control withcurrent-voltage double closed loop will be adopted. An improved repetitivecontrol algorithm on the basis of the conventional PI control of the currentinner-loop is recommended, which promises the unit power factor and thestable output voltage. So the better control performance is relized. Then theReversible bi-directional Buck and Boost DC/DC converter is discussed in itsworking principle and topology. Of course the current closed-loop PI regulatoris designed, which makes the charge and discharge currents’ size and directionbetween the batteries of electric vehicles and grid easy to control.Thirdly, according to the results of the above research an simulationmodel of the whole system is built by Matlab/Simulink simulating software.Therefore, a successful simulation is completed to prove our analysis andconclusion. Lastly, the experimental platform of three-phase PWM rectifier systembased on TMS320F2812DSP are designed and established successfully and allthe programs are compiled and debugged with the C language under theintegrated development environment----Code Composer Studio3.3. In order toimprove the control quality of the network side current and realize the correctphase-locking of the current, a current PLL improved scheme based on thepre-phase-locking and forgotten algorithm are put forward.The experimentalresults show that the control strategy proposed is feasible and reliableexperiment proof is provided.