Investigation And Simulation Of The Combined Energy Storage System Of Fuel Cell And Ultracapacitor

Fuel Cell Electric Vehicle (FCEV) is new energy vehicle which use fuel cell as its main power system. Fuel cell is a new type of energy power system that produces energy through the chemic reactor between hydrogen and oxygen. The ultracapacitors, however new, are an attractive energy due to their high power density, long lifetime, and high efficiency during discharge and re-charging. The power system can have better economy and dynamics than that which base on individual energy system, if ultracapacitors can work with other energy components such as engine, battery, and fuel cell and so on. It's an effective way to use the energy produced by regenerative breaking and reduce pollution. Ultracapacitors have already found application in the propulsion system of HEV as well as fuel cell vehicles.The FCEV introduced in this thesis is developed by the Wuhan University of Technology and Dong Feng Motor Company. We analysis the performance of the whole power system and components when add ultracapacitor to the powertrain. This paper introduce the advantage that ultracapacitor as a kind of efficient energy storage system used in fuel cell electric vehicle. Through analyzes the character of ultracapacitor as storage energy, current and voltage are changed, and the influence brought by temperature, establishes physical model and mathematical model of the ultracapacitor. In the end, a simulation model based mathematical model is set up by MATLAB/SIMULINK, and analysis the effect produced by ultracapacitor that base on the compound energy system.In the hybrid energy system which composed by ultracapacitor, battery and fuel cell, distribute the energy between these energy system logically is very important. This paper analysis the disadvantage and advantage between switch mode and power follow mode, and built a logical energy strategy between fuel cell, ultracapacitor, and battery. Then, the dynamic performance and fuel economy of the powertrain which added ultracapacitor on the UDDS driving cycle are simulated by advisor software. Compared with the primary vehicle of similar fuel economy, the dynamic performance and the components efficiency of the new powertrain are greatly improved.