Battery SOC calibration method

Abstract

The invention provides a battery SOC calibration method. The method comprises the following steps of S1, judging whether a platform area exists or not under a static calibration condition, if so, starting OCV-SOC table look-up calibration, and then carrying out a step S2, otherwise, directly carrying out the step S2; S2, judging whether a charging mode is adopted or not, if yes, reading the current SOC value, the charging current, the charged time and the highest charging cell voltage, then executing the step S3, and if not, executing the step S2; S3, carrying out static voltage slope calibration; S4, limiting the growth rate for calibration; and S5, performing charging terminal voltage calibration. The SOC calibration method is advantaged in that SOC calibration is carried out in three modes of Dq / Dv relation, charging terminal voltage and static voltage slope judgment in the charging process, calibration errors caused by the fact that the battery cell exists in a platform area are avoided, and therefore the SOC calibration method is suitable for SOC calibration of different types of battery cells.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a battery SOC calibration method. Background technique [0002] As the market has higher and higher requirements for new energy vehicles, energy storage, and 3C electronic products, batteries, as one of the key components, have attracted much attention. SOC (State of Charge, state of charge) estimation is one of the key technologies of battery management. It is used to determine the remaining state of charge of the battery. Inaccurate estimation of its value may easily cause battery overcharge, overdischarge, and reduce battery life. [0003] The SOC estimation accuracy is mainly affected by two aspects, one is the SOC process calculation accuracy, and the other is the SOC calibration accuracy. The calculation accuracy of SOC process can be improved by increasing the acquisition accuracy and calculation algorithm of voltage, current and temperature. SOC calibration is mainly ...

AI Technical Summary

Problems solved by technology

This method is not suitable for batteries with a platform voltage range, such as lithium iron phosphate batteries, which may easily cause large calibration errors due to factors such as the accuracy of the OCV-SOC relationship table and the acquisition voltage and temperature.

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