Correction method for estimated state-of-charge value of energy storage device, management apparatus for energy storage device, and energy storage apparatus

1 . A correction method for an estimated state-of-charge value of an energy storage device estimated by a current integration method, the method comprising:

charging the energy storage device;

determining a correction value of the estimated state-of-charge value based on an amount of electricity charged during a period from a start of charge of the energy storage device to a decrease in a current value of a charge current to a predetermined threshold; and

correcting the estimated state-of-charge value according directly to the correction value of the estimated state-of-charge value determined in the determining,

wherein in the determining, the correction value is determined based on a temperature of the energy storage device and the amount of electricity, and

wherein in the determining, an eigenvalue [Ah] corresponding to a combination of the temperature of the energy storage device and the amount of electricity is acquired from eigenvalue information in which the combination of the temperature of the energy storage device and the amount of electricity is associated with the eigenvalue, and the correction value is determined from Equation 1 below:

Correction value [%]=(actual capacity of energy storage device [Ah]−eigenvalue [Ah])/actual capacity of energy storage device [Ah]×100  <Equation 1>.

2 . The correction method according to claim 1 , wherein the energy storage device has a plateau region in which an amount of change in open circuit voltage with respect to an amount of change in state of charge is small, and

wherein the determining of the correction value of the estimated state-of-charge value is directly for the estimated state-of-charge value.

3 . The correction method according to claim 1 , further comprising measuring a temperature of the energy storage device at predetermined time intervals with a temperature sensor when charge of the energy storage device is started and updating the predetermined threshold in accordance with the measured temperature,

wherein the correction value is of the estimated state-of-charge value itself.

4 . The correction method according to claim 1 , wherein the correcting of the estimated state-of-charge value comprises overwriting the estimated state-of-charge value with the correction value.

5 . The correction method according to claim 1 , wherein the correcting of the estimated state-of-charge value comprises changing the estimated state-of-charge value with the correction value, and

wherein the estimated state-of-charge value is corrected immediately after the correction value is determined, or the estimated state-of-charge value is corrected after the correction value is corrected based on the amount of electricity charged and discharged during a time lag.

6 . The correction method according to claim 1 , wherein the correcting of the estimated state-of-charge value is at a time of full charge of the energy storage device.

7 . A correction method for an estimated state-of-charge value of an energy storage device estimated by a current integration method, the method comprising:

charging the energy storage device;

determining a correction value of the estimated state-of-charge value based on an amount of electricity charged during a period from a start of charge of the energy storage device to a decrease in a current value of a charge current to a predetermined threshold; and

correcting the estimated state-of-charge value according directly to the correction value of the estimated state-of-charge value determined in the determining,

wherein

the energy storage device comprises an engine starting energy storage device for starting an engine of a vehicle, and

in the determining, when a time from a last stop of the engine to a start of the engine is equal to or shorter than a predetermined time, a correction value of the estimated state-of-charge value is determined based on a total value of an amount of electricity charged during a period from a start of the engine and a start of charge of the energy storage device last time to the last stop of the engine and an amount of electricity charged during a period from a start of the engine and a start of charge of the energy storage device this time to a decrease in the current value of the charge current to the predetermined threshold.

8 . A management apparatus for an energy storage device, comprising:

a current sensor that measures a charge-discharge current of the energy storage device; and

a management part;

wherein the management part comprising a processor that is configured to perform:

measuring a charge current of the energy storage device with the current sensor,

estimating a state of charge of the energy storage device by a current integration method,

determining a correction value of an estimated state-of-charge value based on an amount of electricity charged from a start of charge of the energy storage device; and

correcting the estimated state-of-charge value according directly to the determined correction value of the estimated state-of-charge value,

wherein in the determining, the correction value is determined based on a temperature of the energy storage device and the amount of electricity, and

wherein in the determining, an eigenvalue [Ah] corresponding to a combination of the temperature of the energy storage device and the amount of electricity is acquired from eigenvalue information in which a combination of the temperature of the energy storage device and the amount of electricity is associated with the eigenvalue, and the correction value is determined from Equation 2 below:

Correction value [%]=(actual capacity of energy storage device [Ah]−eigenvalue [Ah])/actual capacity of energy storage device [Ah]×100  <Equation 22.

9 . The management apparatus according to claim 8 , wherein in the determining, the correction value is determined based on an amount of electricity charged during a period from the start of charge of the energy storage device to a decrease in a current value of a charge current to a predetermined threshold.

10 . The management apparatus according to claim 8 , wherein in the determining, the correction value is determined based on the amount of electricity charged from the start of charge, at which the energy storage device is in a plateau region where an amount of change in open circuit voltage with respect to an amount of change in state of charge is small.

11 . The management apparatus according to claim 9 , wherein the management part is further configured to perform:

measuring a temperature of the energy storage device with a temperature sensor; and

updating the predetermined threshold in accordance with the measured temperature.

12 . The management apparatus according to claim 8 , wherein the correcting further comprises overwriting the estimated state-of-charge value with the correction value.

13 . The management apparatus according to claim 8 , wherein the correcting of the estimated state-of-charge value comprises changing the estimated state-of-charge value with the correction value, and

wherein the estimated state-of-charge value is corrected immediately after the correction value is determined, or the estimated state-of-charge value is corrected after the correction value is corrected based on the amount of electricity charged and discharged during a time lag,

wherein the correcting of the estimated state-of-charge value is at a time of full charge of the energy storage device.