Research On A Novel Energy Storage System For Extended Range Electric Vehicle

In order to meet the requirements of energy saving and emission reduction,the development of new energy vehicle(NEV)has become a worldwide research topic.Extended range electric vehicle(EREV)as one type of NEV can reduce emission comparing to the traditional fuel vehicle,and also can increase the driving range comparing to the pure electric vehicle(PEV),so it has recently become the focus of considerable attention among vehicle manufacturing companies and research institutions.The energy storage system as one of the key technologies of EREV can greatly affect the performance of the vehicle,so efficient energy storage system for EREV has become a very hot research topic nowadays.The main contents studied in this thesis are as following:(1)The latest applications of various energy storage technologies for EREV are mainly discussed and analyzed,such as battery,ultra-capacitor(UC),flywheel,fuel cell,solar and hybrid power supply(HPS).The characteristics of these energy storage technologies are also presented.(2)Several common energy storage systems for EREV are deeply discussed.In view of their shortcomings,a novel energy storage system for EREV is proposed.The super capacitor bank is added as an energy buffer unit in this system,which can effectively improve the charging and discharging performance of the power supply.It can take full advantage of the high energy density of the battery and the high power density of the super capacitor bank to achieve reasonable and effective control of the energy flow.In addition,several working modes of this novel energy storage system are described in detail.(3)Energy management strategies are generated for the proposed novel energy storage system for EREV,including control strategies for pure electric work mode,mutually independent work mode,hybrid power driving mode and energy feedback work mode.It focuses on analyzing the control strategy of the energy assist unit during energy output and feedback processes.(4)The simulation model of this novel energy storage system was built by Matlab/Simulink.There are a composite power supply consisting of a battery and a super capacitor bank that can be switched in series and parallel,a BDPC power converter and an H-bridge inverter in this simulation model.The energy output and feedback characteristics of this novel energy storage system for EREV were calculated,and the rationality of its system energy management strategy was verified.(5)For the proposed energy storage system,an experimental platform was set up to verify the feasibility and superiority of the program.The results show that this new system can improve its energy utilization to a certain extent compared with the traditional composite power supply composed of battery and super-capacitor bank,and improve the feedback efficiency by 5% when the energy is returned.