Method and apparatus for correcting SOC, battery management system and storage medium
A method and apparatus for correcting a state of charge (SOC) is provided. The method includes: acquiring state data of a battery cell in a case where the battery cell meets a preset standing condition, wherein the state data includes: current and voltage data, the preset standing condition is that the current in the state data is less than a preset current threshold, wherein a length of the voltage data in the state data is greater than a preset length; calculating an estimated steady-state Open Circuit Voltage (OCV) value according to the state data, under a condition that a change value of the voltage data in the state data is greater than a preset change threshold; determining a SOC correction value corresponding to the estimated steady-state OCV value; and correcting a current SOC by using the SOC correction value corresponding to the estimated steady-state OCV value.
1. A method for correcting a State of Charge (SOC), comprising:
acquiring state data of a battery cell in a case where the battery cell meets a preset standing condition, wherein the state data of the battery cell comprises: current and voltage data, the preset standing condition is that the current in the state data of the battery cell is less than a preset current threshold, wherein a length of the voltage data in the state data of the battery cell is greater than a preset length;
calculating an estimated steady-state Open Circuit Voltage (OCV) value according to the state data of the battery cell, under a condition that a change value of the voltage data in the state data of the battery cell is greater than a preset change threshold;
determining a SOC correction value corresponding to the estimated steady-state OCV value; and
correcting a current SOC by using the SOC correction value corresponding to the estimated steady-state OCV value.
2. The method according to claim 1 , wherein the state data of the battery cell further comprises: State of Health (SOH) and temperature;
wherein the calculating the estimated steady-state OCV value according to the state data of the battery cell comprises:
determining a steady-state time period threshold corresponding to the SOH and the temperature in the state data of the battery cell; and
calculating the estimated steady-state OCV value according to the voltage data in the state data of the battery cell and the steady-state time period threshold.
3. The method according to claim 1 , wherein the determining the SOC correction value corresponding to the estimated steady-state OCV value to correct the current SOC comprises:
determining whether the estimated steady-state OCV value exceeds a preset estimated OCV range; and
determining, when the estimated steady-state OCV value does not exceed the preset estimated OCV range, the SOC correction value corresponding to the estimated steady-state OCV value to correct the current SOC.
4. The method according to claim 1 , further comprising:
determining an estimated unsteady-state OCV value according to the state data of the battery cell, under a condition that the change value of the voltage data in the state data of the battery cell is smaller than the preset change threshold;
determining a SOC correction value corresponding to the estimated unsteady-state OCV value; and
correcting the current SOC by using the SOC correction value corresponding to the estimated unsteady-state OCV value.
5. The method according to claim 4 , further comprising:
determining a voltage rebound direction during a standing time period of the battery cell;
wherein the correcting the current SOC by using the SOC correction value corresponding to the estimated unsteady-state OCV value, comprises:
correcting the current SOC by using the SOC correction value corresponding to the estimated unsteady-state OCV value under a condition that the voltage rebound direction indicates a voltage increase and the SOC correction value corresponding to the estimated unsteady-state OCV is greater than the current SOC.
6. The method according to claim 5 , wherein the correcting the current SOC by using the SOC correction value corresponding to the estimated unsteady-state OCV value, comprises:
correcting the current SOC by using the SOC correction value corresponding to the estimated unsteady-state OCV value under a condition that the voltage rebound direction indicates a voltage decrease and the SOC correction value corresponding to the estimated unsteady-state OCV is smaller than the current SOC.
7. The method according to claim 2 , wherein the calculating the estimated steady-state OCV value according to the voltage data in the state data of the battery cell and the steady-state time period threshold comprises:
determining a change of a near-steady-state OCV over time according to the voltage data of the battery cell; and
calculating the estimated steady-state OCV value according to the change of the near-steady-state OCV over time and the steady-state time period threshold.
8. The method according to claim 2 , wherein the preset current threshold is determined based on the SOC and the temperature.
9. The method according to claim 1 , wherein the preset length is determined according to the current in the state data of the battery cell.
10. A battery management system, comprising a processor and a memory storage;
the memory storage, configured to store a program thereon; and
the processor, configured to:
acquire state data of a battery cell in a case where the battery cell meets a preset standing condition, wherein the state data of the battery cell comprises: current and voltage data, the preset standing condition is that the current in the state data of the battery cell is less than a preset current threshold, wherein a length of the voltage data in the state data of the battery cell is greater than a preset length;
calculate an estimated steady-state Open Circuit Voltage (OCV) value according to the state data of the battery cell, under a condition that a change value of the voltage data in the state data of the battery cell is greater than a preset change threshold;
determine a SOC correction value corresponding to the estimated steady-state OCV value; and
correct a current SOC by using the SOC correction value corresponding to the estimated steady-state OCV value.
11. The battery management system according to claim 9 , wherein the state data of the battery cell further comprises: State of Health (SOH) and temperature; and
the processor is further configured to:
determine a steady-state time period threshold corresponding to the SOH and the temperature in the state data of the battery cell; and
calculate the estimated steady-state OCV value according to the voltage data in the state data of the battery cell and the steady-state time period threshold.
12. The battery management system according to claim 9 , wherein the processor is further configured to:
determine whether the estimated steady-state OCV value exceeds a preset estimated OCV range; and
determine, when the estimated steady-state OCV value does not exceed the preset estimated OCV range, the SOC correction value corresponding to the estimated steady-state OCV value to correct the current SOC.
13. The battery management system according to claim 9 , wherein the processor is further configured to:
determine an estimated unsteady-state OCV value according to the state data of the battery cell, under a condition that the change value of the voltage data in the state data of the battery cell is smaller than the preset change threshold;
determine a SOC correction value corresponding to the estimated unsteady-state OCV value; and
correct the current SOC by using the SOC correction value corresponding to the estimated unsteady-state OCV value.
14. The battery management system according to claim 13 , wherein the processor is further configured to:
determine a voltage rebound direction during a standing time period of the battery cell;
correct the current SOC by using the SOC correction value corresponding to the estimated unsteady-state OCV value under a condition that the voltage rebound direction indicates a voltage increase and the SOC correction value corresponding to the estimated unsteady-state OCV is greater than the current SOC.
15. The battery management system according to claim 14 , wherein the processor is further configured to:
correct the current SOC by using the SOC correction value corresponding to the estimated unsteady-state OCV value under a condition that the voltage rebound direction indicates a voltage decrease and the SOC correction value corresponding to the estimated unsteady-state OCV is smaller than the current SOC.
16. The battery management system according to claim 10 , wherein the processor is further configured to:
determine a change of a near-steady-state OCV over time according to the voltage data of the battery cell; and
calculate the estimated steady-state OCV value according to the change of the near-steady-state OCV over time and the steady-state time period threshold.
17. The battery management system according to claim 10 , wherein the preset current threshold is determined based on the SOC and the temperature.
18. The battery management system according to claim 9 , wherein the preset length is determined according to the current in the state data of the battery cell.