Study On The Control Strategy And Construction Of Drive System For A Light Fuel Cell Hybrid Vehicle

This paper studies the light vehicle with fuel cell. By analyzing the application ofair-cooled hydrogen-air fuel cell in the light vehicle, we wish to substitute numerous lightvehicles powered by batteries and mini internal combustion engines with the light vehiclepowered by air-cooled hydrogen-air fuel cell so as to better protect the environment. Hence,the light hybrid electric vehicle powered by proton exchange membrane fuel cell (PEMFC) isdeveloped, manufactured and tested. The main studying contents are as follows:1. Analysis on the PEMFC working mechanism employed in vehicles. The PEMFC workingmechanism analyzed in this paper including fuel cell running mechanism,electrochemistry mode as well as the main components of fuel cell. The paper probed intothe application circumstance of materials including bipolar plate, diffusing layer, catalystlayer and proton membrane and worked out how their reactants transmit inside. Analysisis emphasized on the reasons of fuel cell power recession, probing into the measures oflessening their recession.2. Analysis on the light PEMFC hybrid vehicle control strategy and modeling simulation.Control strategies of the light PEMFC hybrid vehicle are necessary conditions to keep thevehicle work normally and save energy, therefore, based on different control strategiesanalysis, Simulink is applied to build simulation diagram of control strategy, to simulateby inserting the simulation diagram into a self-development light PEMFC hybrid vehiclesimulation model, it aims to estimate the advantages and disadvantages of all the controlstrategies and to find out the optimal development of the vehicle control strategies.According to dynamics principles, the motor power is estimated to be3kW, which setsthe minimum consumption of the fuel as its principle, optimizing the fuel cell andbatteries dynamic parameters. In addition, the economic efficiency and powerperformance of the established light PEMFC hybrid vehicle are estimated based on thedeveloped simulation model.3. Analysis on the PEMFC stacks model establishment, manufacture, test and powerrecession employed in vehicles. A2kW stack model is established with a size of100mm *60mm*345.68mm according to analysis on air-cooled stack heat transfer mechanism.The working conditions and flow distributions of the fuel cell are optimized throughsimulation so as to make the reference to designing air-cooled stack. An equal heatdiffusing model is built at the end of the stack exit and the stack heat diffusing isreinforced so as to maintain the equal temperature distribution in the stack according tothe air-cooled stack features. Based on the simulation, an air-cooled hydrogen-air fuel cellstack is developed, manufactured, where the stack gas management system, heatmanagement system as well as security control system are established. Test analysis isconducted in the university bench through LABVIEW which compiles the test procedure.Meanwhile, a5kW stack power recession is tested to estimate the using cost of lightvehicle with PEMFC hybrid power.4. The rebuilding and test analysis of light PEMFC hybrid vehicle. A light PEMFC hybridvehicle is built according to simulation results. The original golf cart is adapted and itspower system is removed. The motor and batteries are selected and purchased, aself-made fuel cell stack is built and the driving chains of light PEMFC hybrid vehicle arerebuilt. According to the requirements of the light vehicle features, simplifying thevehicle main controller, adding DC/DC converter control function, improving fan controlfunction. Finally, bench test and road test are conducted to estimate the vehicleperformance as well as its control strategies.The researching result indicates the advantages of light PEMFC hybrid vehicle lie in thedesign and manufacture flexibility, which is convenient for the project to carry on. Theemphasis is to validate the normal working of the stack, preventing its fast recession; thevehicle control system is supposed to be simple and effective, which is to protect the stackand to reduce fuel consumption. A better simulation can better design the stack and estimatethe vehicle performance, which is benefit for the project development.