Research And Implementation Of Energy Management Method For New Multi Source Charging Converter Of Electric Vehicle

Since the 21st century,the problem of energy shortage and environmental pollution has become increasingly serious.Governments of various countries have formulated long-term planning policies for energy use and environmental protection,and the electric vehicle industry has been booming.In the process of using electric vehicles,through the effective management of energy,we can maximize the use of the performance of electric vehicle charger,and play an important role in the construction of smart grid.In recent years,vehicle photovoltaic energy supply technology,V2G(Vehicle to grid)application technology,vehicle to vehicle energy conversion technology,energy management system,vehicle ad hoc network and so on have become hot research topics.Taking the multi-source charging converter of electric vehicle as the research object,aiming at the emergency charging of electric vehicle and its application requirements in smart grid,this paper proposes a multi-source electric vehicle charging system architecture based on EMS(Energy Manage System).The multi-source charging system is composed of vehicle photovoltaic charging circuit,battery energy exchange circuit between electric vehicles,battery energy exchange circuit between power grid and electric vehicles,battery management,energy management and CAN(Controller Area Network)communication subsystem,so as to realize the reliability,safety and good communication coordination of energy interaction in the system.Vehicle photovoltaic charging circuit realizes the conversion of solar energy to electric energy,as to achieve the purpose of efficient use of solar energy.The dual half bridge DC/DC circuit is used in the battery energy exchange circuit between electric vehicles,which realizes the energy exchange between local vehicle batteries and foreign vehicle batteries,and provides the mobile function of emergency charging for electric vehicles.Two way AC/DC circuit is used in the grid side and double half bridge DC/DC circuit is used in the battery side to realize the two-way flow of energy between the grid and the battery of electric vehicles,so as to realize the V2G application of peak shifting and valley filling.These converter circuits share the dual half bridge DC/DC circuit,so this paper studies the working principle of the dual half bridge DC/DC circuit soft switching,adopts the multi-channel interleaving topology,analyzes the unipolar modulation strategy of the bidirectional AC/DC circuit,and designs the BMS(Battery Manage System)of the distributed architecture,so that the multi-source electric vehicle charging system can meet the power expansion of different power levels of electric vehicles,and improve the versatility of multi-source charging converter.In response to the current application requirements for orderly and convenient charging of electric vehicles and V2V,and to build an integrated platform for vehicle piles and networks,the paper proposes an ad hoc network communication architecture based on vehicle terminals.The information interaction between the piles,the vehicle terminal network and the cloud platform improves the traffic capacity of road traffic,relieves the pressure of the electric system on the disorderly charging of electric vehicles,and ensures the speed and convenience of electric vehicle emergency conversion smart charging and smart travel.In view of the fact that the OCV(Open Circuit Voltage)cannot be applied to the SOC(State of Charge)of electric vehicle batteries,this paper selects the best performance lithium iron phosphate battery to conduct research,and the H∞ filter can be used to accurately estimate the battery SOC value in real time;for electric vehicle battery packs In this paper,the independent passive balance circuit topology and average value balance algorithm are used to manage the battery balance control.This paper presents the main parameters design of bidirectional DC/DC converter and bidirectional AC/DC circuit,the hardware design of communication circuit,and the software design of energy conversion system,ad hoc network communication system,battery SOC and equalization control.The simulation model and the experimental prototype of 3.3kw electric vehicle multi-source charging converter are built.Through simulation and experimental analysis,the feasibility and effectiveness of the theoretical analysis and design method are verified.