Simulation Research Of Energy Management For Electric Vehicle Composite Power Supply

Under the dual pressure of the energy shortage and energy saving and environmental protection, countries around the world are actively developing new energy vehicle,the global auto industry moves towards the age of “energy saving,emission reduction”.Compared with the way to drive the vehicles using oil and other fossil fuels, electric vehicle using the power to replace,has the incomparable superiority in solving the energy crisis and environmental pollution,will be the leading direction of the future automobile development and the long-term solution of the future traffic.Vehicle power battery is the core of the development of electric vehicle.So far,battery defects of low specific power,high current charge-discharge limited and short life cycle seriously affect the performance and restrict the development of electric vehicle.Super capacitor is a new energy storage unit with high specific power,long cycle life,large current fast charge-discharge.Combining super capacitor with battery,can have complementary of respective advantages.The battery can meet the requirements of average power while the super capacitor is used to fill the acceleration and peak power requirement,and when the vehicle is during regenerative braking,the super capacitor can maximally absorb the braking energy,which can effectively balance the electric vehicle dual requirement of power and energy.In this paper,the research object is electric vehicle hybrid power.According to the characteristics of composite power supply and the vehicle power meeting,the battery and bi-directional DC/DC converter in series with super capacitor directly connected to the load is chosen.Next,according to the driving conditions of electric vehicle,the energy management allocation control strategy based on fuzzy neural network control is established.In the Matlab/Simulink environment,the simulation model of electric vehicle power system is established.According to the energy level of super capacitor in the composite power supply the simulation experiment is carried on.The simulation results show that,composite power system can give full play to its high energy density and high power density characteristics,improve motive power and energy efficiency of electric vehicle while protecting the battery and absorbing the braking energy effectively.