BATTERY REMAINING CAPACITY DETECTING APPARATUS AND BATTERY REMAINING CAPACITY DETECTING METHOD

• US 20080030169A1
• Filed: 07/30/2007
• Published: 02/07/2008
• Est. Priority Date: 08/03/2006
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kamishima, Utaka, Nakazawa, Shinsuke
• Granted Patent: US 7,688,032 B2
• Time in Patent Office: Days
• US Class Current: 320/134
• CPC Class Codes: G01R 31/3828 using current integration

Abstract

A battery remaining capacity detecting apparatus includes a remaining capacity calculating section, first and second target remaining capacity calculating sections and a remaining capacity revising section. The first and second target remaining capacity calculating sections are configured to calculate first and second target remaining capacities using first and second calculation processes when first and second prescribed battery related conditions are satisfied, respectively. The second calculating process has a lower accuracy than the first calculation process, and the second prescribed battery related condition is satisfied with a higher frequency than the first prescribed battery related condition. The remaining capacity revising section is configured to revise the remaining capacity toward the first and second target remaining capacities using revision amounts equal to or smaller than first and second revision amount upper limit values, respectively with the second revision amount upper limit value being smaller than the first revision amount upper limit value.

Claims

1. A battery remaining capacity detecting apparatus comprising:

a remaining capacity calculating section configured to calculate a remaining capacity of a battery by an integration calculation process based on a value obtained by integrating one of a charge/discharge current and a charge/discharge power of the battery over time;

a first target remaining capacity calculating section configured to calculate a first target remaining capacity of the battery using a first calculation process that is different from the integration calculation process when a first prescribed battery related condition is satisfied;

a second target remaining capacity calculating section configured to calculate a second target remaining capacity of the battery using a second calculation process when a second prescribed battery related condition is satisfied, the second calculation process being different from the integration calculation process and the first calculation process with the second calculating process for calculating the second target remaining capacity having a lower accuracy than the first calculation process for calculating the first target remaining capacity, the second prescribed battery related condition being satisfied with a higher frequency than the first prescribed battery related condition; and

a remaining capacity revising section configured to revise the remaining capacity calculated by the remaining capacity calculating section toward the first target remaining capacity using a revision amount equal to or smaller than a first revision amount upper limit value when the first prescribed battery related condition is satisfied, and to revise the remaining capacity calculated by the remaining capacity calculating section toward the second target remaining capacity using the revision amount equal to or smaller than a second revision amount upper limit value when the second prescribed battery related condition is satisfied, the second revision amount upper limit value being smaller than the first revision amount upper limit value.

2. The battery remaining capacity detecting apparatus as recited in claim 1, wherein

the remaining capacity revising section includes a maximum error calculating section configured to calculate a maximum value of a calculation error of the remaining capacity calculated by the remaining capacity calculating section, the remaining capacity revising section being further configured to limit the revision amount to a value equal to or smaller than the maximum calculation error value calculated by the maximum error calculating section.

3. The battery remaining capacity detecting apparatus as recited in claim 2, further comprising

a time measuring section configured to measure an amount of time elapsed since a previous revision of the remaining capacity by the remaining capacity revising section,

the maximum error calculating section being configured to calculate the maximum value of the calculation error of the remaining capacity calculated by the remaining capacity calculating section based on the amount of time measured by the time measuring section and a maximum error per unit time of the remaining capacity obtained by the integration calculation process.

4. The battery remaining capacity detecting apparatus as recited in claim 1, wherein

the first target remaining capacity calculating section is configured to calculate the first target remaining capacity based on a terminal voltage of the battery when the first prescribed battery related condition is satisfied in which an absolute value of the charge/discharge current of the battery is smaller than a first prescribed current value that substantially corresponds to a no-load state of the battery, and

the second target remaining capacity calculating section is configured to calculate an internal resistance of the battery, to calculate an open-circuit voltage of the battery based on the internal resistance, the terminal voltage and the charge/discharge current of the battery, and to calculate the second target remaining capacity based on the open-circuit voltage when the second prescribed battery related condition is satisfied in which the absolute value of the charge/discharge current of the battery is smaller than a second prescribed current value that is larger than the first prescribed current value.

5. The battery remaining capacity detecting apparatus as recited in claim 4, wherein

the first target remaining capacity calculating section is configured to calculate the first target remaining capacity based on the terminal voltage of the battery when a prescribed amount of time has elapsed since the first prescribed battery related condition was satisfied.

6. The battery remaining capacity detecting apparatus as recited in claim 1, wherein

the first target remaining capacity calculating section is configured to calculate the first target remaining capacity based on a terminal voltage of the battery when the first prescribed battery related condition is satisfied in which an absolute value of the charge/discharge current of the battery is smaller than a first prescribed current value that substantially corresponds to a no-load state of the battery, and

the second target remaining capacity calculating section is configured to calculate an I-V line indicating a current of the battery relative to a voltage of the battery based on a plurality of charge/discharge current values and a plurality of terminal voltage values detected, to calculate an open-circuit voltage of the battery based on the I-V line, and to calculate the second target remaining capacity based on the open-circuit voltage when the second prescribed battery related condition is satisfied in which the charge/discharge current value of the battery and the terminal voltage of the battery have been detected for a predetermined number of times over time.

7. The battery remaining capacity detecting apparatus as recited in claim 1, wherein

the first target remaining capacity calculating section is configured to calculate an internal resistance of the battery, to calculate a first open-circuit voltage of the battery based on the internal resistance, the terminal voltage and the charge/discharge current of the battery, and to calculate the first target remaining capacity based on the first open-circuit voltage when the first prescribed battery related condition is satisfied in which an absolute value of the charge/discharge current of the battery is smaller than a prescribed current value, and

the second target remaining capacity calculating section is configured to calculate an I-V line indicating a current of the battery relative to a voltage of the battery based on a plurality of charge/discharge current values and a plurality of terminal voltage values detected, to calculate a second open-circuit voltage of the battery based on the I-V line, and to calculate the second target remaining capacity based on the second open-circuit voltage when the second prescribed battery related condition is satisfied in which the charge/discharge current value of the battery and the terminal voltage of the battery have been detected for a predetermined number of times over time.

8. The battery remaining capacity detecting apparatus as recited in claim 1, further comprising

a third target remaining capacity calculating section configured to calculate a third target remaining capacity of the battery using a third calculation process when a third prescribed battery related condition is satisfied, the third calculation process being different from the integration calculation process, the first calculation process and the second calculation process with the third calculation process for calculating the third target remaining capacity having a lower accuracy than the second calculation process for calculating the second target remaining capacity, the third prescribed battery related condition being satisfied with a higher frequency than the second prescribed battery related condition,

the remaining capacity revising section being further configured to revise the remaining capacity calculated by the remaining capacity calculating section toward the third target remaining capacity using the revision amount equal to or smaller than a third revision amount upper limit value that is smaller than the second revision amount upper limit value when the third prescribed battery related condition is satisfied.

9. The battery remaining capacity detecting apparatus as recited in claim 8, wherein

the first target remaining capacity calculating section is configured to calculate the first target remaining capacity based on a terminal voltage of the battery when the first prescribed battery related condition is satisfied in which an absolute value of the charge/discharge current of the battery is smaller than a first prescribed current value that substantially corresponds to a no-load state of the battery,

the second target remaining capacity calculating section is configured to calculate an internal resistance of the battery, to calculate a second open-circuit voltage of the battery based on the internal resistance, the terminal voltage and the charge/discharge current of the battery, and to calculate the second target remaining capacity based on the second open-circuit voltage when the second prescribed battery related condition is satisfied in which the absolute value of the charge/discharge current of the battery is smaller than a second prescribed current value that is larger than the first prescribed current value, and

the third target remaining capacity calculating section is configured to calculate an I-V line indicating a current of the battery relative to a voltage of the battery based on a plurality of charge/discharge current values and a plurality of terminal voltage values detected, to calculate a third open-circuit voltage of the battery based on the I-V line, and to calculate the third target remaining capacity based on the third open-circuit voltage when the third prescribed battery related condition is satisfied in which the charge/discharge current value of the battery and the terminal voltage of the battery have been detected for a predetermined number of times over time.

10. A battery remaining capacity detecting method comprising:

calculating a remaining capacity of a battery by an integration calculation process based on a value obtained by integrating one of a charge/discharge current and a charge/discharge power of the battery over time;

calculating a first target remaining capacity of the battery using a first calculation process that is different from the integration calculation process when a first prescribed battery related condition is satisfied;

calculating a second target remaining capacity of the battery using a second calculation process when a second prescribed battery related condition is satisfied, the second calculation process being different from the integration calculation process and the first calculation process with the second calculating process for calculating the second target remaining capacity having a lower accuracy than the first calculation process for calculating the first target remaining capacity, the second prescribed battery related condition being satisfied with a higher frequency than the first prescribed battery related condition;

revising the remaining capacity calculated by the integration calculation process toward the first target remaining capacity using a revision amount equal to or smaller than a first revision amount upper limit value when the first prescribed battery related condition is satisfied; and

revising the remaining capacity calculated by the integration calculation process toward the second target remaining capacity using the revision amount equal to or smaller than a second revision amount upper limit value when the second prescribed battery related condition is satisfied, the second revision amount upper limit value being smaller than the first revision amount upper limit value.

11. The battery remaining capacity detecting method as recited in claim 10, wherein

the calculating of the first target remaining capacity includes calculating the first target remaining capacity based on a terminal voltage of the battery when the first prescribed battery related condition is satisfied in which an absolute value of the charge/discharge current of the battery is smaller than a first prescribed current value that substantially corresponds to a no-load state of the battery, and

the calculating of the second target remaining capacity includes calculating an internal resistance, calculating an open-circuit voltage of the battery based on the internal resistance, the terminal voltage and the charge/discharge current of the battery, and calculating the second target remaining capacity based on the open-circuit voltage when the second prescribed battery related condition is satisfied in which the absolute value of the charge/discharge current of the battery is smaller than a second prescribed current value that is larger than the first prescribed current value.

12. The battery remaining capacity detecting method as recited in claim 11, wherein

the calculating of the first target remaining capacity includes calculating the first target remaining capacity based on the terminal voltage of the battery when a prescribed amount of time has elapsed since the first prescribed battery related condition was satisfied.

13. The battery remaining capacity detecting method as recited in claim 10, wherein

the calculating of the first target remaining capacity includes calculating the first target remaining capacity based on a terminal voltage of the battery when the first prescribed battery related condition is satisfied in which an absolute value of the charge/discharge current of the battery is smaller than a first prescribed current value that substantially corresponds to a no-load state of the battery, and

the calculating of the second target remaining capacity includes calculating an I-V line indicating a current of the battery relative to a voltage based on a plurality of charge/discharge current values of the battery and a plurality of terminal voltages of the battery detected, calculating an open-circuit voltage of the battery based on the I-V line, and calculating the second target remaining capacity based on the open-circuit voltage when the second prescribed battery related condition is satisfied in which the charge/discharge current value of the battery and the terminal voltage of the battery have been detected for a predetermined number of times over time.

14. The battery remaining capacity detecting method as recited in claim 10, wherein

the calculating of the first target remaining capacity includes calculating an internal resistance, calculating a first open-circuit voltage of the battery based on the internal resistance, the terminal voltage and the charge/discharge current of the battery, and calculating the first target remaining capacity based on the first open-circuit voltage when the first prescribed battery related condition is satisfied in which an absolute value of the charge/discharge current of the battery is smaller than a prescribed current value, and

the calculating of the second target remaining capacity includes calculating an I-V line indicating a current of the battery relative to a voltage based on a plurality of charge/discharge current values of the battery and a plurality of terminal voltages of the battery detected, calculating a second open-circuit voltage of the battery based on the I-V line, and calculating the second target remaining capacity based on the second open-circuit voltage when the second prescribed battery related condition is satisfied in which the charge/discharge current value of the battery and the terminal voltage of the battery have been detected for a predetermined number of times over time.

15. The battery remaining capacity detecting method as recited in claim 10, further comprising

calculating a third target remaining capacity of the battery using a third calculation process when a third prescribed battery related condition is satisfied, the third calculation process being different from the integration calculation process, the first calculation process and the second calculation process with the third calculation process for calculating the third target remaining capacity having a lower accuracy than the second calculation process for calculating the second target remaining capacity, the third prescribed battery related condition being satisfied with a higher frequency than the second prescribed battery related condition, and

revising the remaining capacity calculated by the integration calculation process toward the third target remaining capacity using the revision amount equal to or smaller than a third revision amount upper limit value that is smaller than the second revision amount upper limit value when the third prescribed battery related condition is satisfied.

16. The battery remaining capacity detecting method as recited in claim 15, wherein

the calculating of the first target remaining capacity includes calculating the first target remaining capacity based on a terminal voltage of the battery when the first prescribed battery related condition is satisfied in which an absolute value of the charge/discharge current of the battery is smaller than a first prescribed current value that substantially corresponds to a no-load state of the battery,

the calculating of the second target remaining capacity includes calculating an internal resistance, calculating a second open-circuit voltage of the battery based on the internal resistance, the terminal voltage and the charge/discharge current of the battery, and calculating the second target remaining capacity based on the second open-circuit voltage when the second prescribed battery related condition is satisfied in which the absolute value of the charge/discharge current of the battery is smaller than a second prescribed current value that is larger than the first prescribed current value, and

the calculating of the third target remaining capacity includes calculating an I-V line indicating a current of the battery relative to a voltage based on a plurality of charge/discharge current values of the battery and a plurality of terminal voltages of the battery detected, calculating a third open-circuit voltage of the battery based on the I-V line, and calculating the third target remaining capacity based on the third open-circuit voltage when the third prescribed battery related condition is satisfied in which the charge/discharge current value of the battery and the terminal voltage of the battery have been detected for a predetermined number of times over time.

17. A battery remaining capacity detecting apparatus comprising:

remaining capacity calculating means for calculating a remaining capacity of a battery by an integration calculation process based on a value obtained by integrating one of a charge/discharge current and a charge/discharge power of the battery over time;

first target remaining capacity calculating means for calculating a first target remaining capacity of the battery using a first calculation process that is different from the integration calculation process when a first prescribed battery related condition is satisfied;

second target remaining capacity calculating means for calculating a second target remaining capacity of the battery using a second calculation process when a second prescribed battery related condition is satisfied, the second calculation process being different from the integration calculation process and the first calculation process with the second calculating process for calculating the second target remaining capacity having a lower accuracy than the first calculation process for calculating the first target remaining capacity, the second prescribed battery related condition being satisfied with a higher frequency than the first prescribed battery related condition;

first target remaining capacity revising means for revising the remaining capacity calculated by the integration calculation process toward the first target remaining capacity using a revision amount equal to or smaller than a first revision amount upper limit value when the first prescribed battery related condition is satisfied; and

second target remaining capacity revising means for revising the remaining capacity calculated by the integration calculation process toward the second target remaining capacity using the revision amount equal to or smaller than a second revision amount upper limit value when the second prescribed battery related condition is satisfied, the second revision amount upper limit value being smaller than the first revision amount upper limit value.