SOC correction method and system during changing process of battery state quantity

Abstract

The invention discloses an SOC correction method and a system during the changing process of the battery state quantity. The method comprises the steps of recording battery state parameters at a preset frequency during the operation of a battery; calculating the variation value of each battery state parameter within a time period corresponding to the preset frequency within a preset time span; calculating the difference between two adjacent variation values; determining a reference SOC value according to the difference between adjacent variation values of the battery state parameters; detecting a current actual SOC value and comparing the current actual SOC value with the reference SOC value; on the condition that the deviation exists between the current actual SOC value and the reference SOC value, correcting the current actual SOC value to be the reference SOC value. The system comprises a battery state parameter memory module, a battery state parameter variation value calculating module, a battery state parameter variation value difference calculating module, a reference SOC value determination module and a correction module. According to the technical scheme of the invention, the SOC accuracy of a battery pack of different aging degrees and in different environments can be improved. Meanwhile, the occurrence of errors caused by the poor consistency and property changes, such as the series-parallel connection of batteries, the aging of batteries, the environmental change and the like, can be eliminated.

Description

Technical field [0001] The present invention relates to the technical field of electric vehicles, and more specifically, to a method and system for SOC correction according to the change process of battery state quantity. Background technique [0002] For electric vehicles, power battery is a very common energy storage component, and its performance plays a decisive role in the performance of the whole vehicle. Among power batteries, lithium-ion batteries are used as an important energy storage medium, which has been obtained in the field of new energy. Wide range of applications. The remaining battery capacity, also known as the State of Charge (SOC) of the battery, is one of the important parameters of the battery state, which provides a basis for the control strategy of the electric vehicle. Accurately estimate the current remaining battery power, ensure that the SOC is maintained within a reasonable range, prevent overcharge or overdischarge from damage to the battery, and p...

AI Technical Summary

Problems solved by technology

[0003] At present, the SOC estimation mainly adopts the ampere-hour integration plus open-circuit voltage correction method. The ampere-hour integration will generate errors. If the error is not eliminated, the accumulated error will become larger and larger, which cannot meet the requirements of SOC estimation accuracy. It can be eliminated by correction. error can greatly improve SOC estimation accuracy

However, the current SOC correction adopts the open-circuit voltage correction method, which relies on the original data provided by the cell manufacturer, and cannot eliminate the characteristics changes caused by battery aging, environmental changes, etc. error

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