Research On Energy Recovery Efficiency Of Automobile Exhaust Thermoelectric Power Generation System Based On MPPT Algorithm

With the rapid development of industrialization in various countries in the world,people’s living standards have generally improved.While automobiles have brought convenience to people,they have also brought serious environmental problems.The energy efficiency of automobiles has always been low,about 23% to 37%.Therefore,how to improve the utilization rate of automobile fuel and reduce the emission of automobile exhaust has become the focus and difficulty of the current automobile industry research.The automobile exhaust temperature difference power generation system is one of the current research hotspots.A thermoelectric generator(TEG)is a component that converts the exhaust gas produced by a car from thermal energy to electrical energy.It is one of the important components for exhaust heat recovery.Under certain conditions,increasing the temperature difference between the cold and hot ends of the TEG can increase the thermoelectric power generation system recovery efficiency.How to obtain the maximum power of the thermoelectric power generation system is the key to improving the recovery efficiency of the thermoelectric power generation system.Therefore,how to make the thermoelectric power generation system always work at the maximum power point and effectively improve fuel economy is the focus of this paper.This paper relies on the National Natural Science Foundation of China General Project(No.51977100)to carry out research on the power generation system of automobile tail temperature difference.The thesis first introduces the structure,principle and related thermoelectric materials of thermoelectric generators,and compares and analyzes the structure of flat,cylindrical and fin thermoelectric generators with thermoelectric generator structure as the research object.Secondly,a digital model of the thermoelectric power generation device was established,and the overall structure and key components of the thermoelectric power generation device were designed.The DC-DC circuit,the control circuit of the maximum power algorithm is introduced,and a Boost circuit based on the state space averaging method is proposed based on the analysis of the traditional Boost and Buck circuits.Finally,the current maximum power point tracking algorithm of the thermoelectric power generation system-the disturbance observation method is introduced in detail.Based on the current research status at home and abroad,the existing theory is improved and innovated,and the thermoelectric power generation device is optimized.For the disturbance observation method(P&O)and the open circuit voltage method(OCV)deficiency,this paper introduced the binary gradient algorithm,used the improved algorithm Matlab/simulink to analyze and compare the output power and output voltage of the system,and the simulation test shows that the tracking efficiency of the improved algorithm is higher than that of the disturbance observation method(P&O),about a 3%increase.Compared with the open circuit voltage method(OCV),it is increased by 5%,and the algorithm result is closer to the true value.Therefore,the algorithm proposed in this paper provides certain guidance for the design and optimization of the vehicle tail temperature difference power generation device.