Study On Heat Production Characteristics And Heat Dissipation Performance Of 48V Battery Pack Based On Semiconductor Refrigeration Technology

At present,under the dual pressure of energy and environment,new energy vehicles have developed rapidly.Due to its outstanding advantages in terms of emission reduction and economy,the 48 V light hybrid system has become one of the technological breakthroughs.As the core component of a 48 V system,the performance,life and safety of lithium-ion batteries are closely related to temperature.For 48 V battery pack,high power is bound to bring high heat production,so thermal management must be carried out to maintain the best state and efficiency of the battery.Thermoelectric cooling has the advantages of small size,compact structure,no need for refrigerants,and low thermal inertia.When traditional cooling methods cannot meet the needs,rational use of thermoelectric cooling technology for thermal management of battery packs is an ideal solution.In this paper,the heat production of battery packs and its thermoelectric cooling system.The main research contents are as follows:1)Theoretical analysis of the working principle and heat production model of the lithium-ion battery is carried out.Through experiments,the ohmic internal resistance,polarization internal resistance,and electromotive force temperature rise coefficient of the battery change law with temperature and SOC are obtained,and the other related physical properties of the battery are measured and calculated parameters,a three-dimensional simulation model of a lithium-ion battery cell was established,and the experiment verified the accuracy of the established battery cell heat production model.2)The temperature of the cold ends and hot ends of the thermoelectric cooler and its change trend are measured through experiments at different currents and voltages,and the appropriate working current of the thermoelectric cooler is 3.2A.According to the working principle of the thermoelectric cooler,the normal working voltage of the thermoelectric cooler module is derived in relation to the pressure drop and the Seebeck voltage,the internal resistance is calculated to be 1.8Ω,and the Seebeck coefficient is0.065V/K.Based on the experimental data,a three-dimensional simulation model of the thermoelectric cooler is established.3)Screen 14 batteries with relatively consistent capacity and combine them in series to form a 48 V battery pack,build a battery pack thermal management system based on the thermoelectric cooling effect,and perform temperature changes when the battery pack is discharged at different currents under different ambient temperatures.Experiment and simulation research,analyze the heat dissipation effect of the thermoelectric cooling system under normal temperature and high temperature conditions.4)Using the built 48 V battery pack thermoelectric cooling system model,simulate and analyze the influence of factors such as cooling air speed,cooling air temperature and operating current of the cooling fin on the cooling effect of the battery thermal management system.Under reasonable cooling conditions,the thermoelectric cooling system can meet the heat dissipation requirements of battery pack operating under extreme conditions where the temperature does not exceed 42°C.