Study On Control Strategy And System Design Of Fuel Cell Hybrid Electric Vehicle

In recent years,the contradiction between economic development and both environmental pollution and energy shortage has become increasingly acute.Fuel cell,which uses hydrogen as fuel,has the characteristics of high energy density and pollution-free,and is considered as a promising vehicle energy source.The working characteristics of a fuel cell make it impossible for it to be used alone to drive automobiles.Hybrid electric vehicles driven by fuel cells and batteries,with fuel cells as energy accumulators and batteries as power buffers,can give full play to their advantages and improve energy efficiency and fuel economy.In this paper,a fuel cell + battery hybrid system is designed for fuel cell hybrid electric vehicle,and a prototype vehicle is built as an experimental platform.The power splitting control strategy is proposed,and the feasibility is verified by simulation and vehicle experiments.The main contents of this paper are as follows:(1)By analyzing the advantages and disadvantages of several kinds of hybrid power system topology,the topology of fuel cell hybrid electric vehicle is determined.The parameters of key components such as proton exchange membrane fuel cell,lithium ion battery and boost DC/DC converter are matched.(2)A signal acquisition and control system based on NI is designed,and the acquisition and filtering of electrical signals are realized.On this basis,the performance tests of fuel cell,lithium battery and DC/DC converter are carried out,and the power distribution function of hybrid power system is tested to ensure that the function of the built electric vehicle is perfect.(3)For the hybrid power system,a Rule-based power splitting control strategy and an Equivalent Consumption Minimization Strategy(ECMS)are proposed.(4)Simulation analysis and real vehicle experiments on rule-based control strategy and ECMS show that both strategies can split the total power of the hybrid system in real time.Compared with Rule-based strategy,ECMS can effectively improve the efficiency of fuel cell and the branch of fuel cell and DC/DC Converter,reduce hydrogen consumption and improve fuel economy.