Speed Optimization Of Intelligent EV In Consideration Of Battery Aging

The rapid increase in the number of vehicles has brought tremendous pressure on energy and the environment.In order to cope with such a severe situation,it is imperative to develop EV with zero emission.At the same time,under the trend of intelligent vehicle,the development of intelligent EV with the function of speed optimization has attracted much attention.Lithium ion battery is a kind of obvious advantages of EV power battery,but its price is high,and life is still not long enough.Therefore,the speed optimization strategy not only should optimize the battery energy utilization rate,should also consider the impact on battery aging.Taking the pure electric intelligent vehicle as the research object,the mathematical model of the battery aging can be established by analyzing the internal mechanism of the performance degradation of the lithium ion battery.Then,on the acceleration condition,the optimal control problem of the speed optimization considering the battery aging is constructed,and a reasonable solution is put forward.Finally,the power system model is established,and the simulation results of the speed optimization strategy considering the battery aging are compared with the battery energy consumption optimization strategy to verify its performance.In view of speed optimization of intelligent EV in consideration of battery aging,this paper has done the following aspects of the work:(1)Summarized the background and significance of this research,and pointed out some problems in the field of energy management,lithium-ion battery life model and speed optimization.Finally,it shows the importance of the speed optimization of intelligent EV in consideration of battery aging.(2)Introduced the main components of the lithium ion battery,and expounded the material,structure and application scope of the anode and cathode.The working principle of lithium ion battery was described by taking lithium iron phosphate battery as an example.Based on this,the internal mechanism of lithium ion battery performance degradation was analyzed.Finally,combined with the existing research results of life model,the general life model of lithium iron phosphate battery was constructed.(3)Described the problem of peed optimization of intelligent EV in the acceleration phase,and then constructed the optimal control problem of the corresponding speed optimization.Based on the actual situation of this paper,the state equation,constraints and performance indicators of the optimal control system was written.In this paper,a model for calculating the decay rate of battery capacity in an acceleration period was proposed to derive the performance function of speed optimization in consideration of battery aging.Finally,the optimal control method was used to solve the proposed optimization problem.(4)The dynamic system model of intelligent EV was established,and the main parameters related to vehicle module,motor and inverter module and battery module were described in detail.And then to build the model based on the vehicle dynamics were verified.Then the numerical method was used to fit the performance formula of the speed optimization considering battery aging and considering the energy consumption of the battery.Finally,Solved and compared the two simulation results of the different speed optimization strategies under different working conditions and temperature by the fmincon function.It shows that the speed optimization of intelligent EV in consideration of battery aging can improve the battery energy consumption at the same time play an effective role in protecting the battery to extend its service life under the acceleration condition.