The Simulation Research On Powertrain Parameter Design And Control Strategy Of Extended Range Electric Vehicle

With the energy crisis and environmental pollution becoming increasingly serious,the research and development of new energy vehicles has become an inevitable trend in the development of the automotive industry.However,at the current stage,the rapid development of pure electric vehicles is restricted due to the lack of breakthrough in related technologies of battery system.In this context,extended range electric vehicle(EREV)that can use as much electric energy as possible and effectively reduce fuel consumption have become a hot research topic in the automotive industry.This paper takes the EREV as the research object,designing and researching the powertrain and control strategy of the whole vehicle.The main research contents are as follows:(1)According to the vehicle performance design index,the key components of the powertrain of the EREV are compared and selected and parameterized,and then the corresponding vehicle simulation model is established in the simulation software,and the simulation verified that the designed powertrain parameters are reasonable.(2)In order to more reasonable distribution of power between the engine and the battery,a engine three-point control strategy which comprehensively considers the vehicle demand power,battery SOC,speed and acceleration is proposed.Simulation results show that this strategy is superior to the power following control strategy in terms of CO emission,fuel consumption and energy efficiency of the vehicle.Moreover,because the strategy has acceleration judgment conditions,it can make the vehicle’s SOC curve fall more slowly and the battery life is longer under the condition of rapid acceleration.(3)A mathematical model of instantaneous optimal power distribution based on ECMS is built for the extended-range electric vehicle.A proportional-integral controller is used to control the standard equivalent factor so that it can be adaptively adjusted according to the SOC value,and proposed the method of orthogonal calculation to determine the proportional term constant and the integral term constant.The simulation results prove that compared with the first two control strategies based on deterministic rules,this strategy has fewer CO emissions,lower fuel consumption,and higher vehicle energy efficiency.(4)Based on the ideal braking force distribution strategy,the corresponding fuzzy control strategy is designed for the distribution of regenerative braking force,and the regenerative braking force is restricted and modified according to the influence of vehicle speed,SOC and motor characteristics.The simulation results under self-built braking conditions and cycle conditions show that the regenerative braking control strategy designed in this paper can not only meet the design requirements,but also can effectively improve the energy recovery efficiency compared with the ADVISOR’s default regenerative braking control strategy.After that,the driving and regenerative braking control strategies are combined,and the simulation results proved that the combined strategy can make the vehicle’s fuel economy and vehicle energy efficiency better.(5)In order to further improve the control effect of fuzzy control in regenerative braking,genetic algorithm is used to optimize the membership function parameters in fuzzy control.The simulation results show that the optimized fuzzy control strategy has different degrees of improvement in pure electric driving range,vehicle energy efficiency,and braking energy recovery efficiency.