| With the new development situation of the new energy vehicles all over the world in recent years, the Formula Student Electric China(FSEC) gradually have been quite extensive widely promotion in motorsport, especially popular in Colleges and Universities. The limits of its movement and extreme competitions conditions caused the power battery system for pure electric racing cars easily overheating or bad heat dissipation, and the research and application of battery thermal management can effectively improve the problem and improved safety and reliability. But before, very few have researched on the electric car battery system in-depth combined with the dynamic conditions in FSEC. Therefore, the cobalt acid lithium power battery system on pure electric racing car was regarded as the research object in this paper, combined with dynamic FSEC conditions. To ensure that the battery always working within the highest energy efficiency of the temperature range and improve the safety for the car by the reasonable design of battery thermal management system.In this paper, the source of the battery heat was analyzed firstly based on the heat generation mechanism, a three-dimensional thermal battery model and simplified Bernardi heat generation rate model were established, the equivalent thermal parameters of the battery also obtained by theoretical estimation means. And test platform for battery internal resistance was built, the data of equivalent resistance for battery also obtained by the test, it provides the foundation for the analysis of thermal characteristics for the battery.The heat transfer process inside the battery heat generation was qualitatively analyzed based on the basic heat transfer and heat dissipation theory, the temperature thermal characteristics of to the battery cell in FSEC dynamic conditions were analyzed with ANSYS/thermal finite element thermal analysis software. The temperature acquisition system was designed, and the temperature platform of the battery pack was established to monitor the surface temperature changing on the battery. The thermal model and parameters was verified by comparing analysis results of the simulation and the experimental data, and the changing process of the temperature were in good consistent, the maximum error is no more than 8%.From the principle of energy-saving and lightweight, the capacity requirements and parameters matching were calculated to battery power system for electric racing car. The cooling demand in the FSEC dynamic conditions was analyzed according to the thermodynamics theory, and the battery cooling system was designed preliminarily based on the requirements of the FSEC rules and the arrangement for the vehicle. Then the orthogonal experimental design method was used to optimize the structure of the battery cooling system, the position of the cooling fan and the arrangement of the cells were regarded as the main influence factors, to decrease the maximum temperature as the prerequisite and maximize lower temperature difference for the target, and a parameterized battery simulation model based on ANSYS/Icepak was established, the simulation results show that the maximum temperature difference is optimized by 40%.Finally, the manufacturing of entity was completed and the assembly of the battery system also was finished, and the results of simulation were in good agreement with the experimental results, and the maximum error was less than 2℃, which indicates that the design in this paper can ensure the car battery system has good heat dissipation performance in FSEC, and the prospective goal is achieved. At the same time, the safety requirements for car was satisfied, and it also has certain directive significance for the future design and development of the FSEC electric racing car. |
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