Research On Smoothness Of Mode Switching Process Based On PHEV Of P2 Configuration

As traditional fuel vehicles are facing increasingly serious energy and environmental problems,new energy vehicle technology is constantly developing.Among them,hybrid vehicles have become one of the mainstream solutions in the market due to the advantages of not being restricted by battery life and charging facilities.The biggest feature of hybrid vehicles is the addition of an electric motor as a new power source,which improves vehicle performance through flexible work mode switching,followed by more complex control strategies of mode switching.Frequent mode switching will reduce the smoothness of the vehicle and affect the drivers’ and passengers’ comfort.This article takes this issue as the research object,and studies the smoothness of the mode switching process based on PHEV(Plug-in Hybrid Electric Vehicle)of P2 configuration.The main research contents of this paper include:Firstly,based on a Chery PHEV of P2 configuration,according to its system structure and main technical parameters,the key components are analyzed and modeled,including engine,motor,battery,K0 clutch and DCT(Dual Clutch Transmission);Because there is no complete system and method for the evaluation of the smoothness of the hybrid vehicle mode switching process,this paper proposes objective evaluation indicators and theoretical analysis of mode switching process,designs experiments to obtain subjective and objective evaluation results of mode switching process,analyze and research based on experimental data,use Pearson correlation coefficient to verify the consistency of objective smoothness evaluation indicators and subjective comfort evaluation scores,and construct a subjective and objective evaluation model of mode switching process through BP(Back Propagation)neural network.This evaluation model is used to improve the evaluation efficiency and reliability during the development of vehicles,and guide the optimization of the control strategy.For the study of the mode switching control strategy,first determine the working area of each mode and the torque distribution of the two power sources in each mode,and propose the basic control method of each main component.Secondly,the various types of mode switching processes are analyzed.Based on the analysis results combined with the subjective and objective evaluation models established above,the key control parameters of each component are optimized.Based on the optimization results,control strategies for various mode switching are formulated,and the mode switching process simulation is performed.The simulation results are input into the evaluation model to get the prediction scores,which verifies the effectiveness of mode switching smoothness optimization.The research results in this paper show that the objective smoothness evaluation indicators proposed in this paper are consistent with the human subjective comfort scoring scores.The trained subjective and objective evaluation model can obtain predicted scores more reasonably.The mode switching control strategies are obtained based on the key control parameters of each component after optimization.The strategies can improve the smoothness of the hybrid vehicle mode switching process.