Method, device, and system, for state of charge (SOC) correction for a battery

A state of charge (SOC) correction device for a battery, comprising:

• 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,
• wherein the SOC correction device is characterized in that the SOC correction module is further configured to:
• determine a SOC change path formed by the current SOC value and a historical SOC value, and obtain a current estimated OCV value based on processing of the SOC change path by an OCV estimation model component;
• determine, based on the SOC confidence interval and a preset error-range-equal-division parameter k, a SOC correction variation for a SOC correction, when an absolute value of a voltage difference between the current estimated OCV value and the current OCV measurement value is greater than or equal to a voltage difference threshold;
• correct, based on the SOC correction variation and a sign of the voltage difference, the current SOC value to obtain a corrected value of the current SOC value;
• and
• determine a new SOC change path formed by the corrected value of the current SOC value and the historical SOC value, and determine the corrected value of the current SOC value as the SOC correction target value until the absolute value of the voltage difference is less than the voltage difference threshold,
• wherein the preset error-range-equal-division parameter k is used for equally dividing an error range for the current SOC value into k parts to obtain an error list consisting of k SOC error variations:
• [dSOC[1], dSOC[2], dSOC[3], . . . , dSOC[k]], where dSOC[i] in the error list indicates a SOC correction variation for an i-th SOC correction, k is an integer greater than 1, and i is an integer greater than or equal to 1 and less than or equal to k.