A method for rapid identification of life decline characteristics of power battery system

Abstract

The invention discloses a method for rapidly recognizing a life decline characteristic of a power battery system. Based on a pre-established relationship between a polarized internal resistance increase rate and a capacity retention rate, voltage and current data for parameter recognition are acquired under an actual operating condition of an electric car, on-line parameter recognition is performed by a vehicle-mounted computer, and the actual capacity of a battery can be obtained on line without full charge, full discharge or other operations on the battery; the polarized internal resistance increase rate and the capacity retention rate are used as an input and an output, so that influence of inconsistency of the internal resistance and the capacity between batteries on capacity prediction is avoided. The recognized model internal resistance parameters can be not only applied to capacity estimation, but also applied to SOC estimation and the like.

Description

technical field [0001] The invention relates to the field of batteries, in particular to the technology of health management and fault detection of vehicle-mounted power battery systems. Background technique [0002] Lithium-ion power batteries have performance degradation problems during the use of electric vehicles, mainly including capacity loss, increased internal resistance, faster temperature rise, and obvious self-discharge phenomena, which seriously affect the performance and safety of the vehicle. The sign of the end of life of lithium-ion batteries for electric vehicles is that their capacity declines to 80% of the initial capacity, so the online estimation of their available capacity has become a key issue in the research of lithium-ion battery life. The identification of battery life degradation features is not only important in predicting the remaining battery life, but also has a significant impact on the safety of electric vehicles. During the decline of lith...

AI Technical Summary

Problems solved by technology

However, the existing power battery life evaluation method is difficult to estimate the battery capacity online, and the time and material costs of the life test of the power battery system are huge, the results are scattered, and the reference and guidance value is limited. How to obtain the life characteristics of the power battery online Become the key to realize the refined design of electric vehicle system and the optimization of cost control indicators

Images