Research On The Supporting Structural And Heat Balance Of Battery Package Of Hybrid Electric Vehicle

With the increasingly severe problems of resource shortage and environmental protection,the world automobile industry has begun to focus on the research ofhybrid electric vehicle(HEV).Ni-MH battery pack has been viewed as a model storage energy component of the hybrid electric vehicle,its performance and the length of service life have asignificant impacts on the cost performance of the vehicle..Affected by the space of vehicle and the operating condition,Ni-MH battery will generate a lot of heat during the process of charging and discharging,,which will lead to the rise of the battery temperature and inconsistent of temperature in the battery pack without the effective heat dissipation.Consequently,this will cause the degradation of performance and the reduction of service life of the battery pack.At the same time,in order to ensure the reliability of the structure of battery pack,the battery pack should satisfies the strength requirements in various of vehicle operating conditions,therefore the further research on structural strength and heat balance technology of Ni-MH battery pack for improving the service life and the charge and discharge performance of the battery packand assuring safe operation of the whole vehicle are of very important significances.The principle of reaction and heat transfer mechanism of Ni-MH battery pack were analyzed theoretically,and the test of charge and discharge characteristic was also studied in this paper.The test results showed that the temperature of battery has an important effects on DC resistance,charge and discharge efficiency,and available capacity of the battery pack,Moreover,a temperature index of Ni-MH batteries of vehicle has been put forward according to the test results.According to the power demand of the vehicle,the heat dissipation target of the battery pack,and the boundary conditions of the vehicle,the flow field and temperature field of the battery pack were studied with the computational fluid dynamics(CFD)method,numerical simulation analysis,and the optimization of the supporting structural of battery model.Based on themanufacturing process requirementsof the battery pack the finite element analysis method was applied,the supporting structural of battery pack was optimized through the strength and dynamic characteristic simulation of battery supporting structural..Results showed that the battery temperature,the inconsistence of temperature among the battery modules and supporting structural of battery pack could meet the requirements of Ni-MH battery pack of the HEV.In order to verify the designed battery pack,the prototype of the battery pack was established,according to the test standard and test method which can check the performance of the HEV Ni-MH battery pack,the charge and discharge test under the test condition,the temperature field measurement and X,Y,Z three directions endurance and vibration test of Ni-MH battery pack and vehicle 100% frontal crash test wereconducted.The simulation results match well with the test results.Thusthe research achievements had been utilized in deep hybrid electric vehicle-Geely Imprial EC7.