Method and apparatus for correcting state of charge
The present application provides a method and apparatus for correcting a state of charge. The method for correcting a state of charge comprises: determining an operating state of a battery cell, wherein the operating state comprises a discharging state or a charging state; and determining a corrected state of charge of the battery cell according to an acquired current open circuit voltage of the battery cell, an acquired current accumulative capacity of the battery cell, an accumulative capacity correspondence relationship corresponding to the operating state of the battery cell, and an open circuit voltage curve corresponding to a limit initial state of charge, wherein the accumulative capacity correspondence relationship comprises a correspondence relationship between a pre-measured open circuit voltage and an accumulative capacity threshold. A technical solution of the present application can be used to improve the accuracy of calculation of a state of charge.
1. A method for correcting a state of charge, comprising:
determining an operating state of a battery cell, wherein the operating state comprises a charging state;
acquiring a current open circuit voltage of the battery cell;
acquiring a current accumulative charging capacity and a current accumulative discharging capacity of the battery cell; and
using, as a corrected state of charge of the battery cell, a state of charge corresponding to the current open circuit voltage in a charging open circuit voltage curve with an initial state of charge being 0% when the current accumulative discharging capacity is less than a maximum allowed accumulative discharging capacity corresponding to the current open circuit voltage, and the current accumulative charging capacity is greater than a minimum required accumulative charging capacity corresponding to the current open circuit voltage.
2. The method for correcting a state of charge according to claim 1 , wherein the method for correcting a state of charge further comprising:
determining the corrected state of charge of the battery cell according to the corrected state of charge of the battery cell, a first state of charge corresponding to a maximum open circuit voltage in a discharging open circuit voltage curve with an initial state of charge being 100%, and a second state of charge corresponding to a minimum open circuit voltage in a charging open circuit voltage curve with an initial state of charge being 0% when the current accumulative discharging capacity is greater than or equal to the maximum allowed accumulative discharging capacity corresponding to the current open circuit voltage, or the current accumulative charging capacity is less than or equal to the minimum required accumulative charging capacity corresponding to the current open circuit voltage.
3. The method for correcting a state of charge according to claim 2 , wherein the determining the corrected state of charge of the battery cell comprises:
using, as the corrected state of charge of the battery cell, the state of charge corresponding to the maximum open circuit voltage in the discharging open circuit voltage curve with the initial state of charge being 100% when the calculated state of charge of the battery cell is greater than the first state of charge.
4. The method for correcting a state of charge according to claim 2 , wherein the determining the corrected state of charge of the battery cell comprises:
using, as the corrected state of charge of the battery cell, the state of charge corresponding to the minimum open circuit voltage in the charging open circuit voltage curve with the initial state of charge being 0% when the calculated state of charge of the battery cell is less than the second state of charge.
5. The method for correcting a state of charge according to claim 2 , wherein the determining the corrected state of charge of the battery cell comprises:
using the calculated state of charge of the battery cell as the corrected state of charge of the battery cell when the calculated state of charge of the battery cell is less than or equal to the first state of charge, and is greater than or equal to the second state of charge.
6. The method for correcting a state of charge according to claim 1 , wherein the determining an operating state of a battery cell comprises:
acquiring a current temperature of the battery cell, and standing duration of the battery cell up to a current moment;
obtaining minimum standing duration corresponding to the current temperature; and
determining the operating state of the battery cell when the standing duration of the battery cell is longer than the minimum standing duration.
7. The method for correcting a state of charge according to claim 1 , wherein the determining an operating state of a battery cell comprises:
determining that the operating state of the battery cell is the discharging state when the current accumulative charging capacity is greater than the current accumulative discharging capacity.
8. An apparatus for correcting a state of charge, comprising:
a state determination module configured to determine an operating state of a battery cell, wherein the operating state comprises a charging state; and
a correction module configured to acquire a current open circuit voltage of the battery cell, a current accumulative charging capacity and a current accumulative discharging capacity of the battery cell;
the correction module is further configured to:
use, as a corrected state of charge of the battery cell, a state of charge corresponding to the current open circuit voltage in a charging open circuit voltage curve with an initial state of charge being 0% when the current accumulative discharging capacity is less than a maximum allowed accumulative discharging capacity corresponding to the current open circuit voltage, and the current accumulative charging capacity is greater than a minimum required accumulative charging capacity corresponding to the current open circuit voltage.
9. The apparatus for correcting a state of charge according to claim 8 , the correction module is further configured to:
determine the corrected state of charge of the battery cell according to the corrected state of charge of the battery cell, a first state of charge corresponding to a maximum open circuit voltage in a discharging open circuit voltage curve with an initial state of charge being 100%, and a second state of charge corresponding to a minimum open circuit voltage in a charging open circuit voltage curve with an initial state of charge being 0% when the current accumulative discharging capacity is greater than or equal to the maximum allowed accumulative discharging capacity corresponding to the current open circuit voltage, or the current accumulative charging capacity is less than or equal to the minimum required accumulative charging capacity corresponding to the current open circuit voltage.
10. The apparatus for correcting a state of charge according to claim 9 , the correction module is configured to:
use, as the corrected state of charge of the battery cell, the state of charge corresponding to the maximum open circuit voltage in the discharging open circuit voltage curve with the initial state of charge being 100% when the calculated state of charge of the battery cell is greater than the first state of charge.
11. The apparatus for correcting a state of charge according to claim 9 , the correction module is configured to:
use, as the corrected state of charge of the battery cell, the state of charge corresponding to the minimum open circuit voltage in the charging open circuit voltage curve with the initial state of charge being 0% when the calculated state of charge of the battery cell is less than the second state of charge.
12. The apparatus for correcting a state of charge according to claim 9 , the correction module is configured to:
use the calculated state of charge of the battery cell as the corrected state of charge of the battery cell when the calculated state of charge of the battery cell is less than or equal to the first state of charge, and is greater than or equal to the second state of charge.
13. The apparatus for correcting a state of charge according to claim 8 , the state determination module is configured to:
acquire a current temperature of the battery cell, and standing duration of the battery cell up to a current moment;
obtain minimum standing duration corresponding to the current temperature; and
determine the operating state of the battery cell when the standing duration of the battery cell is longer than the minimum standing duration.
14. The apparatus for correcting a state of charge according to claim 8 , the state determination module is configured to:
determine that the operating state of the battery cell is the discharging state when the current accumulative charging capacity is greater than the current accumulative discharging capacity.