Control Strategy Study And Model Development Of Range-Extender For Electric Vehicles

The energy and environmental problems brought about by the rapid development of automobile industry urge countries to promote and develop new energy vehicles vigorously.the extended-range electric vehicle has received extensive attention because of its long cruising range Compared to the pure electric vehicle,.The range extender is the core component of the extended-range electric vehicle powerstrain,great significance should be attached on the control strategy.In this paper,the control strategy for the start-up and stop of the range extender and the generation power follow-up is designed by using the modeling design method,and the modeling development,simulation and experimental verification are completed.This paper has introduced a control strategy for a Ranger Extender,based on its structure,working principle.The power follower strategy is realized by operated in selected curve,which can make a ranger extender in the best performance.The working state transition module of the range extender,the target generating power setting module,the mechanical power feedforward feedback control module and the target torque / speed setting module based on the optimal operating condition trajectory are designed in detail.Then,according to the MAAB modeling specification,the model is built in the Simulink environment.After the completion of the whole control strategy,The specification and function of the model are verified by designing test cases based on Modesl Advisor and Design Verifier in Simulink.Last,the experimental verification of the Simulink Model and the control strategy is introduced.After the genreartion of C-code by the Matlab Embedded Code and the corresponding underlying software,the project is compiled and downloaded to the corresponding chip,through which the control is realized.In the bench environment,start/stop test,parameter tunning test and load characteristic test are designed to verify the effectiveness of the strategy.Results have suggested that the Control Strategy have accomplished start,stop and power function of range extender,Based on the platform and the whole vehicle,the transfer of working state and power decoupling are completed,and the running curve of the extender is verified to meet the expected goal.The PI parameters are adjusted in the real vehicle and bench test,and the power response characteristics and output accuracy are obtained.Experimental results prove the control strategy is reliable and effective,the power error of the range extender is less than 0.5k W and the power overshoot is less than 1.5k W.Besides,results of test in vehicle environment show that the range extender system works stably,the power error is less than 0.6k W,and the power overshoot is less than 1.5k W.