CROSS REFERENCE TO RELATED APPLICATION

The present application is based upon and claims the benefits of Chinese Patent Application No. 201910547687.3 filed on Jun. 24, 2019, the entire contents of which are incorporated herein by reference.

FIELD

The present disclosure generally relates to batteries, and more particularly to a method, a device, a system and a storage medium for state of charge (SOC) correction for a battery.

BACKGROUND

In a battery management system of an electric vehicle, SOC of a battery is used to reflect the remaining capacity of the battery. Moreover, the SOC is also an important parameter for battery capabilities such as equalization control technology, rapid charge and discharge management, safe operation and the like. Therefore, accurate SOC estimation plays an important role in power indication, remaining mileage, over-charge and over-discharge protection, battery balance, charge control and battery health prediction by the battery management system.

At present, a common SOC correction method such as an open circuit voltage (OCV) method may obtain the SOC of the battery in a static state by using a correspondence between an OCV and an SOC. However, for a battery having a hysteresis characteristic, an OCV curve characterizing the correspondence between the OCV and the SOC may be affected by historical operating conditions. Change of the OCV curve may cause a great error of the OCV method, which may reduce the accuracy of SOC correction.

SUMMARY

Embodiments of the present disclosure provide a method, a device, a system, and a storage medium for SOC correction for a battery, which may correct a SOC of a battery having a hysteresis characteristic, and improve accuracy of estimating the SOC of the battery.

In an aspect, the embodiments of the present disclosure provides a SOC correction method for a battery, including: determining a current open-circuit voltage (OCV) measurement value of the battery, and determining whether the current OCV measurement value is within a hysteresis voltage interval, wherein an OCV measurement value within the hysteresis voltage interval satisfies: when a SOC value of the battery in a charging state is equal to a SOC value of the battery in a discharging state, an OCV value corresponding to the SOC value of the battery in the charging state is different from an OCV value corresponding to the SOC value of the battery in the discharging state; determining, when the current OCV measurement value is within the hysteresis voltage interval, a charging SOC value corresponding to the current OCV measurement value in the charging state and a discharging SOC value corresponding to the current OCV measurement value in the discharging state; and determining, based on a SOC confidence interval determined from the charging SOC value and the discharging SOC value, a SOC correction target value to correct a current SOC value of the battery.

In another aspect, the embodiments of the present disclosure provides a SOC correction device for a battery, including: a voltage measurement value determination module configured to determine a current open-circuit voltage (OCV) measurement value of the battery, and determine whether the current OCV measurement value is within a hysteresis voltage interval, wherein an OCV measurement value within the hysteresis voltage interval satisfies: when a SOC value of the battery in a charging state is equal to a SOC value of the battery in a discharging state, an OCV value corresponding to the SOC value of the battery in the charging state is different from an OCV value corresponding to the SOC value of the battery in the discharging state; a SOC determination module configured to determine, when the current OCV measurement value is within the hysteresis voltage interval, a charging SOC value corresponding to the current OCV measurement value in the charging state and a discharging SOC value corresponding to the current OCV measurement value in the discharging state; and a SOC correction module configured to determine, based on a SOC confidence interval determined from the charging SOC value and the discharging SOC value, a SOC correction target value to correct a current SOC value of the battery.

In yet another aspect, the embodiments of the present disclosure provides a SOC correction system for a battery, including: a memory and a processor, wherein: the memory is configured to store executable program codes; and the processor is configured to read the executable program codes stored in the memory to perform the above SOC correction method for a battery.

In still another aspect, the embodiments of the present disclosure provides a computer readable storage medium including instructions which, when executed on a computer, cause the computer to perform the above SOC correction method for a battery.

In the method, device, system and storage medium for SOC correction for a battery according to the embodiments of the present disclosure, influence of the hysteresis characteristic on the SOC of the battery is considered. If the OCV measurement value of the battery is within the hysteresis voltage range, the SOC correction target value may be determined using the charging SOC value corresponding to the current OCV measurement value in the charging state and the discharging SOC value corresponding to the current OCV measurement value in the discharging state, so as to correct the current SOC value. Compared with SOC estimation directly using the OCV value, the SOC correction method of the embodiments of the present disclosure can obtain a more accurate SOC of the battery.

