Method for estimating open-circuit voltage of battery based on gas-liquid dynamic model and device

Abstract

The invention provides a method for estimating the open-circuit voltage of a battery based on a gas-liquid dynamic model and a device. The method for estimating the open-circuit voltage of the batterybased on the gas-liquid dynamic model comprises the following steps that 1, an undetermined open-circuit voltage estimation equation is deduced according to the gas-liquid dynamic model; 2, equationparameters are identified and estimated according to experimental data; and 3, an open-circuit voltage estimation method is designed according to the complete open-circuit voltage estimation equation,and calculating is carried out to obtain an open-circuit voltage estimation value. The open-circuit voltage estimation equation comprises the battery temperature, does not need to be coupled with thebattery temperature again, and simplifies the open-circuit voltage estimation process. The principle of gas dissolution / precipitation in the estimation equation is equivalent to the polarization effect of the battery, the phenomenon that the open-circuit voltage lags the terminal voltage of the battery cab be better fitted. An estimation result of the estimation equation does not depend on the precision of an input initial value, and excellent estimation robustness is achieved. According to the method and device for estimating the open-circuit voltage of the battery based on the gas-liquid dynamic model, the non-linear process of battery charging and discharging can be more accurately depicted, a simple analytical formula, easy parameter identification and small calculation amount are achieved, the influence of battery temperature characteristics on the open-circuit voltage is reflected, and the method and device for estimating the open-circuit voltage of the battery based on the gas-liquid dynamic model is convenient to realize in engineering.

Description

technical field [0001] The invention belongs to the field of battery management systems, and in particular relates to a battery open-circuit voltage estimation method and device based on an aero-hydraulic dynamics model. Background technique [0002] Oil is known as black gold and the blood of industry, but oil resources will gradually become exhausted as humans continue to exploit them. Transportation accounts for nearly half of the total consumption of petroleum, and countries all over the world are trying to find energy sources that can replace petroleum. Among them, vigorously developing electric vehicle technology is one of the important choices. However, during the use of the vehicle-mounted lithium battery, due to the increase of the discharge depth, the decrease of the internal active material, the increase of the EIS film thickness, the increase of the internal resistance, the reversible capacity attenuation and the change of the ambient temperature, some important ...

AI Technical Summary

Problems solved by technology

The intelligent algorithm needs to do a lot of calculations, which also makes it difficult for the model to realize real-time estimation on the vehicle MCU.

[0004] In summary, only relying on the existing battery model is far from meeting the requirements of practical applications. There is an urgent need for a model that can more accurately describe the nonlinear process of battery charge and discharge, reflect the battery temperature characteristics, have simple analytical formulas, and a small amount of calculation. Method and device for estimating open circuit voltage

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