Open-circuit voltage-ampere-hour integral SOC estimation method based on temperature correction

Abstract

The invention relates to an open-circuit voltage-ampere-hour integral SOC estimation method based on temperature correction and belongs to the technical field of battery management. The method comprises the steps that 1, a power battery to be detected is selected to obtain technical parameters of the battery, it is determined whether the battery is provided with a TMS or not, if yes, the battery works under the nominal condition, and if not, the battery works under full condition; 2, an SOC-OCV mapping model based on temperature correction is established, and initial values of an SOC under thenominal condition and the full condition are obtained; 3, a temperature model about total capacity, releasable capacity loss and coulombic efficiency is established, an ampere-hour integral method isused for estimating the SOC under the nominal condition and the full condition; 4, according to the steps 2 and 3, the SOC estimation method under different working conditions is established by adopting an OCV method based on temperature correction and combining with ampere-hour integral, and the SOC under the nominal condition and the full condition are estimated. By adopting the method, the problem of accurate estimation of battery SOC in a wide temperature range is solved.

Description

technical field [0001] The invention belongs to the technical field of battery management, and relates to a temperature-corrected open-circuit voltage-ampere-hour integral SOC estimation method. Background technique [0002] High-precision state of charge (State of Charge, SOC) estimation is one of the key technologies of the battery management system (Battery Management System, BMS), and the accurate estimation of SOC directly or indirectly affects other states of the battery pack (such as life state, temperature, etc.) state, etc.) and parameter estimates. Therefore, the accurate estimation of SOC has extremely important significance. [0003] Currently, SOC estimation methods are divided into the following two categories: model-free SOC estimation methods and model-based SOC estimation methods. The model-free SOC estimation methods include the discharge experiment method and the ampere-hour integration method. The former is reliable and accurate, but it is only suitable...

AI Technical Summary

Problems solved by technology

The traditional method only gives the definition of battery capacity, coulombic efficiency and SOC under the nominal working conditions. In fact, different temperature conditions will lead to the offset of OCP and the existence of NROP, which will introduce errors to the traditional OCV method

Different working conditions will also affect the characteristics of battery capacity and coulombic efficiency, and changes in battery characteristics will adversely affect battery SOC estimation

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