Optimal Design For Hybrid Energy Storage Electrical Architecture Of HEB

With the development of electric vehicles, the situation of battery life becomesincreasingly prominent. Single cell prolong its life-span by improving its ownmanagement system or adding thermal management system. But promotion the space islimited because of the nature of the battery itself.As a result, some hybrid electric busesuse pure capacitance as an auxiliary power source.Yet within the limitation of the capacityof super capacitance,it may calls for multiple capacitances in series or parallel leading toexpensive cost.Then, hybrid energy storage has been presented by researchpersonnel.With the hybrid energy storage system,battaries and capacitances play a part inlarge capacity, high-power in charge and discharge.They learn from each other, greatlyextend the life of the vehicle power supply and power efficiency.The main structure of hybrid energy storage has the following three forms: directparallel,battery load side of the active control and capacitance load side of the activecontrol.Three kinds of forms, due to itssimple and easyengineering, directparallel, hasbeenused in the car in some companies. But the problem of twice of energy conversionreduces the efficiency. Moreover,it needs to match capacitance voltage and the batteryvoltage,for shorting the voltage difference.However,it can increase the capacity ofcapacitance which leads to expensive cost.In the form of battery load side of the activecontrol,the control of DC/DC may bring about certain degree of lag weakening the peakof capacitance.As a result,it can not upgrade the battery life furthest. Therefore,the formof capacitance load side of the active control is used in the paper, the main contents are asfollows:(1)Refer to the progress of hybrid energy storage domestic and oversea. Afterunderstanding of the various properties and characteristics of the vehicle power supply aswell as hybrid buses on-board power requirements, determine this hybrid electric buswith complex power structure.(2)Develop the CAN network protocol about hybrid energy storage system,and realize the simulation of CAN network protocol with the platform of CANoe. Calculate CANnetwork load conditions of hybrid energy storage, propose on-demand CAN protocol, andcompare the advantages and disadvantages of Trigger cycle approachthrough CANoesimulation.(3)Conduct the measure on the component performance of hybrid energystorage,measure thekey parametersand its requirement on hardware and software.Itprovides the basis for the management of hardware and software and control strategies.Use TTC200as the hardware and define the pin function.(4)In the course of collecting the message underline and controlling the hardware,solve the problem of insufficient buffer in CAN. Put forward a way based on TTC200,itcan meet the hardware requirement for hybrid energy storage as well as the real-timerequirement for CAN communication.(5)Build the test bench, and conduct the joint debugging about all components as wellas testing the condition. Solve the problem of the CAN network interference produced byDC/DC module. After testing the performance of DC/DC converter,test the condition ofhybrid energy storage through simulated the current requirement by the Digatron powersimulator. Reflect the advantage of lithium-ionbattery life of using the form ofcapacitance load side of the active control by the means of comparing the changes ofcurrent and voltage.