Aging early warning method and system based on lithium ion battery capacity diving point, automobile and computer storage medium

Abstract

The invention provides an aging early warning method and system based on a lithium ion battery capacity diving point, an automobile and a computer storage medium, and the method comprises the steps: S1, obtaining the operation data of a single lithium ion battery in real time, carrying out the data processing, and obtaining a charging / discharging segment; S2, extracting similar fragments during charging / discharging, and calculating a similarity feature F of the operation fragments; S3, establishing a grey model, and predicting a characteristic curve trend by using the fragment similarity characteristic F to input the model; S4, calculating a residual error e between the prediction data and the real data, and calculating a residual error test score according to a residual error variance, a mean value and an extreme value; And S5, determining a base line according to the data value calculated in the step S4, and judging whether the battery capacity dives or not according to the actual trend of the similarity characteristics of the operation segments and the base line. According to the invention, severe aging early warning of the battery can be given out in advance, and safety accidents of the lithium ion battery are effectively avoided.

Description

technical field [0001] The invention relates to lithium ion battery technology, in particular to the capacity aging technology of lithium ion battery for electric vehicles. Background technique [0002] With the development of new energy technology and the promotion of scientific and technological changes, lithium-ion batteries are more and more widely used due to their high energy density and long service life, but they have also caused a large number of safety accidents, which also makes lithium-ion batteries safe. Sexual security becomes paramount. [0003] Lithium-ion batteries mainly face two types of safety hazards during use: 1) physical collisions; 2) battery aging and failure. Because the damage caused by physical collisions to lithium-ion batteries is relatively easy to observe, manufacturers generally design corresponding boxes to protect lithium-ion batteries. There are relatively many safety accidents caused by failures. The battery management system (BMS) pr...

AI Technical Summary

Problems solved by technology

The problem with this method is that it is necessary to obtain the internal resistance of the new battery

This method needs to obtain capacity degradation curve data, but in the actual use of electric vehicles, due to the uncertainty of sensor acquisition accuracy and charge-discharge SOC interval, the capacity degradation curve is not easy to establish accurately; in addition, this method needs to be identified according to the slope of the capacity degradation curve Curve shape, the capacity degradation curve runs in a full cycle. Based on the identification of the curve shape, it is possible to judge whether the battery has capacity diving, but it is impossible to judge when it happened, and it is difficult to carry out real-time early warning.

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