Input/output power control apparatus and method for secondary battery

• US 20080048619A1
• Filed: 07/11/2007
• Published: 02/28/2008
• Est. Priority Date: 07/12/2006
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Yoshida, Shinsuke
• Granted Patent: US 7,714,543 B2
• Time in Patent Office: Days
• US Class Current: 320/134
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/0038 relating to sensors
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

In input/output power control apparatus and method for a secondary battery, in a case where neither a current sensor nor a voltage sensor fails, allowable input/output powers which are an allowable input power by which the secondary battery allowably inputs and an allowable output power by which the secondary battery allowably outputs are calculated on the basis of an input and/or output current and a terminal voltage of the secondary battery and, in a case where the failure in either one of the current sensor and the voltage sensor is detected, the allowable input/output powers are calculated on the basis of a detected value of one of the current and voltage sensors in which no failure is detected, and each of input and output powers of the secondary battery is limited to be equal to or smaller than the corresponding one of the allowable input/output powers.

Claims

1. An input/output power control apparatus for a secondary battery, comprising:

a current sensor configured to detect an input and/or output current of the secondary battery;

a voltage sensor configured to detect a terminal voltage of the secondary battery;

a sensor failure detecting section configured to detect at least one of failures in the current sensor and in the voltage sensor;

an allowable input/output power calculating section configured to calculate an allowable input power by which the secondary battery allowably inputs and an allowable output power by which the secondary battery allowably outputs in a form of allowable input/output powers on the basis of the terminal voltage detected by the voltage sensor and the input and/or output current of the secondary battery detected by the current sensor, in a case where the sensor failure detecting section detects the failure in neither the current sensor nor the voltage sensor, and to calculate the allowable input/output powers on the basis of a detected value of one of the current sensor and the voltage sensor in which the sensor failure detecting section detects no failure, in a case where the failure detecting section detects the failure in either one of the current sensor and the voltage sensor; and

an input/output power control section configured to limit each of input and output powers of the secondary battery to a value equal to or smaller than the corresponding one of the allowable input/output powers calculated by the allowable input/output power calculating section.

2. The input/output power control apparatus as claimed in claim 1, wherein the sensor failure detecting section comprises a current sensor failure detecting section configured to detect the failure in the current sensor and the allowable input/output power calculating section is configured to calculate the allowable input/output powers of the secondary battery from the terminal voltage detected by the voltage sensor, in a case where the failure in the current sensor is detected by the current sensor failure detecting section.

3. The input/output power control apparatus as claimed in claim 1, wherein the sensor failure detecting section comprises a voltage sensor failure detecting section configured to detect the failure in the voltage sensor and the allowable input/output power calculating section is configured to detect a residual capacity of the secondary battery on the basis of the residual capacity of the secondary battery before the voltage sensor is detected to fail and an accumulated value of the input and/or output current of the secondary battery detected by the current sensor from a time point at which the voltage sensor fails and to calculate the allowable input/output powers of the secondary battery on the basis of the detected residual capacity.

4. The input/output power control apparatus as claimed in claim 1, wherein the sensor failure detecting section is configured to detect the failures in the current sensor and in the voltage sensor and the allowable input/output power calculating section is configured to calculate the allowable input/output powers from the terminal voltage detected by the voltage sensor, in a case where the sensor failure detecting section detects the failure in the current sensor, and to detect a residual capacity of the secondary battery on the basis of the residual capacity before the failure in the voltage sensor and an accumulated value of the input and/or output current of the secondary battery detected by the current sensor from a time point at which the voltage sensor fails and to calculate the allowable input/output powers of the secondary battery on the basis of the detected residual capacity, in a case where the failure in the voltage sensor is detected.

5. The input/output power control apparatus as claimed in claim 2, wherein the allowable input/output power calculating section is configured to calculate the residual capacity of the secondary battery from the terminal voltage detected by the voltage sensor and to calculate the allowable input/output powers on the basis of the calculated residual capacity of the secondary battery, in a case where the failure in the current sensor is detected.

6. The input/output power control apparatus as claimed in claim 2, wherein the allowable input/output power calculating section is configured to previously store a correlation between the allowable input/output powers of the secondary battery and the terminal voltage of the secondary battery and to calculate the allowable input/output powers on the basis of the terminal voltage detected by the voltage sensor and the correlation between the allowable input/output powers and the terminal voltage of the secondary battery, in a case where the failure in the current sensor is detected.

7. The input/output power control apparatus as claimed in claim 3, wherein the allowable input/output power calculating section is configured to calculate the allowable input/output powers on the basis of the detected residual capacity of the secondary battery and a difference in the residual capacity between a predetermined residual capacity upper limit value and a predetermined residual capacity lower limit value.

8. The input/output power control apparatus as claimed in claim 2, wherein the input/output power control apparatus further comprises;

an output time detection section configured to detect an accumulated value of an output time for which the power is outputted from the secondary battery from a time point at which the failure in the current sensor is detected; and

an input time detecting section configured to detect an accumulated value of an input time for which the power is inputted to the secondary battery from the time point at which the failure in the current sensor is detected and wherein the input/output power control section is configured to limit the input power of the secondary battery to be equal to or smaller than an input power limitation value which is equal to or smaller than the allowable input power and to limit the output power of the secondary battery to be equal to or smaller than an output power limitation value which is smaller than the allowable output power and is smaller than the input power limitation value, in a case where the accumulated value of the output time is larger than the accumulated value of the input time by a predetermined time or more, and the input/output power control section is configured to limit the output power of the secondary battery to be equal to or smaller than the input current limitation value which is an electric power equal to or smaller than the allowable output power and to limit the input power of the secondary battery to be equal to or smaller than the input power limitation value which is smaller than the allowable input power and is smaller than the output power limitation value, in a case where the accumulated value of the input time is larger than the accumulated value of the output time by another predetermined time or more.

9. The input/output power control apparatus as claimed in claim 3, wherein the input/output power control apparatus further comprises:

an output current accumulated value detecting section configured to detect an output current accumulated value which is an accumulated value of the output current from the secondary battery from a time point at which the failure in the voltage sensor is detected; and

an input current accumulated value detecting section configured to detect an input current accumulated value which is the accumulated value of the input current to the secondary battery from the time point at which the failure in the voltage sensor is detected and wherein the input/output power control section is configured to limit the input power of the secondary battery to be equal to or smaller than an input power limitation value which is a power equal to or smaller than the allowable input power and to limit the output power of the secondary battery to be equal to or smaller than an output power limitation value which is smaller than the allowable output power and is smaller than the input current limitation value, in a case where the output current accumulated value is larger than the input current accumulated value by a predetermined value or more, and the input/output power control section is configured to limit the output power of the secondary battery to be equal to or smaller than the input power limitation value which is the power equal to or smaller than the allowable output power and to limit the input power of the secondary battery to be equal to or smaller than the input power limitation value which is smaller than the allowable input power and is smaller than the output power limitation value, in a case where the input current accumulated value is larger than the output current accumulated value by another predetermined value or more.

10. The input/output power control apparatus as claimed in claim 1, wherein the input/output power control apparatus further comprises a voltage variation quantity detecting section configured to detect a voltage variation quantity of the terminal voltage of the secondary battery and wherein the input/output power control section is configured to limit the input power of the secondary battery and the output power thereof to be powers which are smaller than the allowable input power and the allowable output power, respectively, in a case where the variation quantity of the terminal voltage of the secondary battery detected by the voltage variation quantity detecting section is larger than a predetermined variation quantity.

11. The input/output power control apparatus as claimed in claim 1, wherein the input/output power control apparatus further comprises a temperature variation quantity detecting section configured to detect a variation quantity of a temperature of the secondary battery and wherein the input/output power control section is configured to limit the input power and the output to be powers which are smaller than the allowable input power and the allowable output power, respectively, in a case where the detected temperature variation quantity detected by the temperature variation quantity detecting section is larger than a predetermined variation quantity.

12. The input/output power control apparatus as claimed in claim 1, wherein the sensor failure detecting section is configured to compare the current flowing through a load which is driven by a power supplied from the secondary battery with the current detected by the current sensor and to detect the failure in the current sensor when the current flowing through the load is larger than the current detected by the current sensor.

13. The input/output power control apparatus as claimed in claim 1, wherein the sensor failure detecting section is configured to compare another voltage inputted to a load driven by the power supplied from the secondary battery with a voltage detected by the voltage sensor and to detect the failure in the voltage sensor when the other voltage inputted to the load is larger than the voltage detected by the voltage sensor.

14. An input/output power control method for a secondary battery, comprising:

providing a current sensor configured to detect an input and/or output current of the secondary battery;

providing a voltage sensor configured to detect a terminal voltage of the secondary battery;

detecting at least one of failures in the current sensor and in the voltage sensor;

in a case where neither the current sensor nor the voltage sensor is detected to fail, calculating an allowable input power by which the secondary battery allowably inputs and an allowable output power by which the secondary battery allowably outputs in a form of the allowable input/output powers on the basis of the input and/or output current detected by the current sensor and the terminal voltage of the secondary battery detected by the voltage sensor and, in a case where the failure in either one of the current sensor and the voltage sensor is detected, calculating the allowable input/output powers on the basis of a detected value of one of the current and voltage sensors in which no failure is detected; and

limiting each of input and output powers of the secondary battery to be equal to or smaller than the corresponding one of the allowable input/output powers.

15. The input/output power control method as claimed in claim 14, wherein the method further comprises detecting whether the failure in the current sensor occurs and wherein, in a case where the failure in the current sensor is detected, the allowable input/output powers of the secondary battery are calculated from the terminal voltage detected by the voltage sensor.

16. The input/output power control method as claimed in claim 14, wherein the method further comprising detecting whether the failure in the voltage sensor occurs and wherein, in a case where the failure in the voltage sensor is detected, a residual capacity of the secondary battery is detected on the basis of the residual capacity before the failure in the voltage sensor is detected and an accumulated value of the input and/or output current of the secondary battery detected by the current sensor, and the allowable input/output powers of the secondary battery are calculated on the basis of the detected residual capacity.

17. The input/output power control method as claimed in claim 14, wherein the method further comprises detecting the failures of both of the current sensor and the voltage sensor occur and wherein, in a case where the failure in the current sensor is detected, the allowable input/output powers are calculated from the terminal voltage detected by the voltage sensor and, in a case where the failure in the voltage sensor is detected, a residual capacity of the secondary battery is detected on the basis of the residual capacity of the secondary battery before the failure in the voltage sensor is detected and an accumulated value of the input and/or output current detected by the current sensor from a time point at which the failure in the voltage sensor is detected, and calculating the allowable input/output powers on the basis of the detected residual capacity of the secondary battery.

18. The input/output power control method as claimed in claim 15, wherein, in a case where the failure in the current sensor is detected, a residual capacity of the secondary battery is calculated from the terminal voltage and the allowable input/output powers are calculated on the basis of the calculated residual capacity of the secondary battery.

19. The input/output power control method as claimed in claim 15, wherein a correlation between the allowable input/output powers of the secondary battery and the terminal voltage of the secondary battery is previously stored and, in a case where the failure in the current sensor is detected, the allowable input/output powers are calculated on the basis of the terminal voltage detected by the voltage sensor and the correlation between the terminal voltage detected by the voltage sensor and the allowable input/output powers of the secondary battery.

20. The input/output power control method as claimed in claim 16, wherein the allowable input/output powers of the secondary battery are calculated on the basis of the detected residual capacity of the secondary battery and a difference in the residual capacity between a predetermined residual capacity upper limit value and a predetermined residual capacity lower limit value.

21. The input/output power control method as claimed in claim 15, wherein, in a case where the failure in the current sensor is detected, the method further comprises detecting an accumulated value of an output time which is a time for which the power is outputted from the secondary battery from a time point at which the failure in the current sensor is detected and detecting another accumulated value of an input time which is a time for which the power is inputted to the secondary battery from the time point at which the failure in the current sensor is detected and, in a case where the accumulated value of the output time is larger than the accumulated value of the input time by a predetermined time or more, limiting the input power of the secondary battery to an input power limitation value which is equal to or smaller than the allowable input power and limiting the output power of the secondary battery to be equal to or smaller than an output power limitation value which is smaller than the allowable output power and is smaller than the input current limitation value, and, in a case where the accumulated value of the input time is larger than the accumulated value of the output time by another predetermined time or more, limiting the output power of the secondary battery to a value equal to or smaller than the input power limitation value which is the power equal to or smaller than the allowable output power and limiting the input power of the secondary battery to a value equal to or smaller than the input power limitation value which is smaller than the allowable input power and is smaller than the output power limitation value.

22. The input/output power control method as claimed in claim 16, wherein, in a case where the failure in the voltage sensor is detected, the method comprises detecting an output current accumulated value which is the accumulated value of the output current from the secondary battery from a time point at which the failure in the voltage sensor is detected and an input current accumulated value which is the accumulated value of the input current to the secondary battery from the time point at which the failure in the voltage sensor is detected and, in a case where the output current accumulated value is equal to or larger than the input current accumulated value by a predetermined value or more, limiting the input power of the secondary battery to a value equal to or smaller than an input power limitation value which is the power equal to or smaller than the allowable input power and limiting the output power of the secondary battery to an output power limitation value which is smaller than the allowable output power and is smaller than the input limitation value and, in a case where the input current accumulated value is larger than the output current accumulated value by another predetermined value or more, limiting the output power of the secondary battery to be equal to or smaller than the input power limitation value which is equal to or smaller than the allowable output power and limiting the input power of the secondary battery to a value equal to or smaller than the input power limitation value which is smaller than the allowable input power and is smaller than the output power limitation value.

23. An input/output power control apparatus for a secondary battery, comprising:

current sensing means for detecting an input and/or output current of the secondary battery;

voltage sensing means for detecting a terminal voltage of the secondary battery;

sensing means failure detecting means for detecting a failures in at least one of the current sensing means and the voltage sensing means;

allowable input/output power calculating means for calculating an allowable input power by which the secondary battery allowably inputs and an allowable output power by which the secondary battery allowably outputs in a form of allowable input/output powers on the basis of the terminal voltage of the secondary battery detected by the voltage sensing means and the input and/or output current detected by the current sensing means, in a case where the sensing means failure detecting means detects the failures in neither the voltage sensing means nor the current sensing means, and for calculating the allowable input and output powers on the basis of a detected value of one of the current sensing means and the voltage sensing means in which no failure is detected, in a case where the sensing means failure detecting means detects the failure in either one of the current sensing means and the voltage sensing means; and

input/output power control means for limiting each of input and output powers of the secondary battery to a value equal to or smaller than the corresponding one of the allowable input/output powers calculated by the allowable input/output power calculating means.

24. The input/output power control apparatus for the secondary battery as claimed in claim 23, wherein the sensing means failure detecting means comprises current sensing means failure detecting means for detecting the failure in the current sensing means and the allowable input/output power calculating means calculates the allowable input/output powers of the secondary battery from the terminal voltage detected by the voltage sensing means, in a case where the current sensing means failure detecting means detects the failure in the current sensing means.

25. The input/output power control apparatus for a secondary battery as claimed in claim 23, wherein the sensing means failure detecting means comprises voltage sensing means failure detecting means for detecting the failure in the voltage sensing means and the allowable input/output power calculating means detects a residual capacity of the secondary battery on the basis of the residual capacity of the secondary battery before the failure in the voltage sensing means and an accumulated value of the input/output current of the secondary battery detected by the current sensing means from a time point at which the failure in the voltage sensing means is detected, in a case where the failure in the voltage sensing means is detected, and calculates the input/output power of the secondary battery on the basis of the detected residual capacity.

26. The input/output power control apparatus as claimed in claim 23, wherein the sensing means failure detecting means detects failures in both of the voltage sensing means and the current sensing means and the allowable input/output power calculating means calculates the allowable input/output powers of the secondary battery from the terminal voltage detected by the voltage sensing means, in a case where the sensing means failure detecting means detects the failure in the current sensing means, detects a residual capacity of the secondary battery on the basis of the residual capacity before the failure in the voltage sensing means and an accumulated value of the input and/or output current of the secondary battery detected by the current sensing means from a time point at which the sensing means failure detecting means detects the failure in the voltage sensing means and calculates the allowable input/output powers of the secondary battery on the basis of the detected residual capacity, in a case where the failure in the voltage sensing means is detected.