Battery ageing state estimation method considering different battery states

Abstract

The invention relates to a battery ageing state estimation method considering different battery states, which comprises the following steps of: 1, establishing an equivalent circuit model for fittingan electrochemical impedance spectroscopy of a single battery; 2, according to the equivalent circuit model, acquiring charge transfer resistance values at different temperatures and charge states soas to obtain a fit data set; 3, constructing a calculation model f (T, SOC) between a charge transfer resistance and the battery temperature as well as the charge state, and according to the fit dataset, determining parameters of an expression; 4, carrying out correction on the calculation model after determining the parameters through fitting; 5, defining a battery standard state, and accordingto the corrected calculation model g (T, SOC), calculating a charge transfer resistance value in the battery standard state; and 6, according to relative growth of the charge transfer resistance converted into the standard state, estimating an ageing state of the battery. Compared to the prior art, the battery ageing state estimation method has the advantages of simplicity and convenience for calculation, reliability for estimation and the like.

Description

technical field [0001] The invention relates to the battery management field of pure electric vehicles and plug-in hybrid electric vehicles, in particular to a battery aging state estimation method considering different battery states. Background technique [0002] With the popularization and application of electric vehicles, the requirements for the safety and reliability of vehicle batteries are gradually increasing, and the aging state estimation of vehicle batteries is a necessary function of advanced battery management systems. The aging of lithium-ion batteries during use directly affects the mileage and output power of electric vehicles. Accurate acquisition of the aging state of the power battery can achieve efficient and safe use of the power battery, and reliable estimation of the aging state of the power battery is essential for improving The research of battery life is of great significance. At present, many methods for estimating the aging state of lithium-ion ...

AI Technical Summary

Problems solved by technology

However, the internal resistance value is affected by the current battery state parameters such as operating temperature, state of charge, etc. These factors are constantly changing during the battery's service life, which limits the universality, reliability and accuracy of the life estimation method using battery internal resistance measurement. very low

If these state variables are strictly controlled, the complexity of the experiment will be greatly increased

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