Study On Engine Control Strategy In Mode Switching Procedure Of RE-EV

Global environmental pollution, depletion of fossil fuels and other issues become moreand more serious in recent years, making people have set their sights on finding new energysources and application. As the automotive industry, the traditional fuel vehicles are alsofacing the same problem. Therefore, most countries have set the electric car as the directionof the future development of the automotive industry after careful study. Three stages ofelectric vehicles are hybrid electric vehicles, pure electric vehicles and fuel cell electricvehicles. Pure electric vehicles become popular in the major car manufacturers because ofits zero-emission characteristics, but the cost of pure electric vehicle and driving rangebecome a limiting factor for its further development at present. As the transition fromhybrid electric vehicle to pure electric vehicle, the range extended electric vehicle can justmake up for these shortcomings of pure electric vehicles, thus becoming the most likelytype to achieve large-scale production of novel energy vehicles.The core technology of the range extended electric vehicle is still driving control andenergy management strategy, which determines the energy flow patterns and work status ofpower system components and thus determines the energy saving potential of the vehicle,and also affect the vehicle powertrain parameters matching and cost of the vehicle. In thedrive control and energy management strategy, the mode switching is very important, andthe mode switching process is very complicated as dynamic process. Mode switchingprocess especially when there are engine start and stop directly affects the efficiency andeffectiveness of mode switching, the paper carried out research in this area.This paper is to study the specific engine control strategies of the mode switchingprocess, mainly for the FAW Technology Center Projects: Study on configuration matchingand vehicle control key techniques of the range extended electric vehicle. This paper is animportant part of the vehicle control system, making the vehicle control strategy moresophisticated, closer to the practical application system, and of great value. The thesis includes the following parts:Firstly, vehicle’s power system configuration and drive models are studied, and themode switching control strategy is analyzed while the power unit parameters are known.The requirements of the engine start for mode switch control process which involving theengine start is analyzed, and then the engine start control method used in this paper isproposed with analyzing its limitations.Secondly, the engine drag torque theoretical analysis and simulation for engine startproblem are carried on.Thirdly, the implementation methods of engine control strategy of the single modeswitching is studied, and the impact of various control parameters on mode switchingprocess is analyzed.Fourthly, the simulation model of vehicle control is established and the performance ofthe proposed control strategy is verified. Above all, the paper introduces the vehiclesimulation model and its major subsystem especially controller module, and then describesthe implementation method of GT-POWER and Simulink co-simulation, and concretelyrealized. For a particular condition to run the simulation model to obtain the variouspowertrain torque and speed response characteristics and vehicle and battery status, the roleof the control strategy in vehicle simulation model are proved in this paper. Finally, the roleto promote vehicle fuel economy of the control strategy in a variety of conditions isanalyzed, and its superiority is proved.The paper studies on engine control strategy in mode switching procedure of RE-EV,itis of great significance to improve the response speed of mode switching and vehicleeconomy.