Method for evaluating influence of whole vehicle feedback overcharge behavior on service life of battery

Abstract

The invention discloses a method for evaluating the influence of a whole vehicle feedback overcharge behavior on the service life of a battery, and the method comprises the steps: carrying out the pulse charging cycle test experiment of different overcharge working conditions on a plurality of experiment groups, and carrying out the cycle test of each overcharge working condition until a battery cell reaches an EOL state, wherein the target pulse voltages under different overcharge working conditions are sequentially set to be different voltage gears, and the capacity and power of the battery cell sample are regularly measured during the experiment period; dividing the plurality of voltage partitions according to voltage gears, counting overcharge information of different voltage partitions in each overcharge working condition and cell life attenuation in each overcharge working condition in a segmented manner, and acquiring cell acceleration factors associated with different overcharge degrees; counting historical overcharge information of different voltage partitions of the power battery; and quantitatively analyzing the influence of the whole vehicle feedback overcharge behavior on the battery cell life of the power battery according to the battery cell acceleration factor and the historical overcharge information. The quantitative analysis of the overcharge behavior of the power battery is realized, and the evaluation precision of the quality guarantee life is improved.

Description

technical field [0001] The present invention relates to the technical field of power battery application evaluation, and more specifically, relates to a method for evaluating the impact of vehicle feedback overcharging behavior on battery life. Background technique [0002] Power battery is one of the indispensable components of electric vehicles, and the performance of batteries directly affects the safety, power, durability and economy of electric vehicles. [0003] In actual vehicle operation, not all single cells work within the optimal voltage range. Battery attenuation, battery management system failure, improper use, etc. will cause the vehicle to overcharge or overdischarge during the braking feedback process. , and then trigger a multi-level fault alarm. In the long run, especially the overcharge behavior has a great impact on the life of the battery system. Therefore, both the quality assurance life assessment and the control strategy adjustment should consider thi...

AI Technical Summary

Problems solved by technology

These works have made significant contributions to the improvement of battery intrinsic design and the safety control of the whole vehicle. However, due to the monitoring and management functions of the battery management system, the probability of battery failure is small, but with the increase of driving mileage, it is in a semi-failure state ( Regenerative braking leads to overcharging, but the proportion of batteries that do not reach the critical condition of thermal runaway) is increasing, and the number of overcharging and overdischarging behaviors is increasing, such as some complex real vehicle working conditions: climbing Slope acceleration, downhill braking, emergency braking, or frequent start and stop, high temperature environment operation, etc.

Images