Research And Development Of Control Strategy Of Fuel Cell Range Extender Electric Vehicle

As an effective solution to environmental pollution and energy shortage,new energy vehicles and related technologies have been paid great attention by countries all over the world.With the advantages of no greenhouse gas emission of pure electric vehicles,and effectively makes up for the deficiency of continuous driving range of pure electric vehicles by introduces the fuel cell system,extended fuel cell electric vehicle has become a key research topic in the field of new energy vehicles in recent years.This paper firstly studies the typical structural arrangement scheme of fuel cell vehicle power system,on this basis,determine the structural form of the extended-range fuel cell electric vehicle power system,and the selection and parameter matching of key components of the power system are carried out in combination with the working characteristics and performance design indexes of the vehicle.Secondly,the research and application status of fuel cell vehicle control strategy are summarized and analyzed.based on computer simulation,the effect of thermostat control strategy and power following control strategy in extended program fuel cell electric vehicle was studied,the aim is to explore a control scheme suitable for the operation characteristics of extended fuel cell electric vehicles.Comprehensive consideration of factors related to power performance,economy,and fuel cell durability,the control strategy of extended fuel cell electric vehicle is development based on fuzzy control theory,the experimental results show that under the developed fuzzy logic control strategy,the average operating efficiency of the fuel cell is 0.22%higher than that of the power following control strategy,the start-stop frequency of the fuel cell is 50%lower than that of the thermostat control strategy,and is 75%lower than that of power following control strategy,however,the control effect of this strategy on the power battery SOC in extended range mode did not meet the design requirements,resulting in the increase of the start-stop frequency of the fuel cell in extended range mode,and affecting the service life of the fuel cell and the fully use of the power performance of the system.Combined with the average power demand of driving conditions and the position information of power battery SOC in the fluctuation interval,the adaptive adjustment function of fuel cell minimum output power was increased based on the fuzzy logic control strategy,better fuel cell durability and system power performance control are achieved.Finally,the vehicle dynamic performance test was carried out based on computer simulation,the rationality of parameter matching of key components and structure form of the power system is verified.Then the comprehensive driving conditions were established to test the control effect of the control strategy under different initial SOC values of power battery and driving conditions.The experimental results show that the improved fuzzy logic control strategy has good adaptability,the fuel cell system can be timely controlled when the power battery SOC drops to a certain extent or the power output of the power battery is insufficient,at the same time,this strategy has a good control effect on the power battery SOC in the extended range mode,effectively reduces the start-stop frequency of the fuel cell in the extended range mode,and is conducive to the protection of the life of the fuel cell and the fully use of the system power performance in the extended range mode.