Battery pack capacity control system

• US 7,439,710 B2
• Filed: 07/26/2004
• Issued: 10/21/2008
• Est. Priority Date: 07/29/2003
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ishishita, Teruo
• Primary Examiner(s): Ullah; Akm E
• Assistant Examiner(s): RAMADAN, RAMY O
• Application Number:
  US10/563,462
• Publication Number:
  US 20060152195A1
• Time in Patent Office: 1,548 Days
• Field of Search: 320/132, 324/426, 324/427, 324/434
• US Class Current: 320/132
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

If the capacity variation is greater than a pre-stored value, the SOC converted from Qmin sometimes cannot recover to a control center value. In such a case, inconveniences including the continuation of an event where the HVECU cannot output a command to stop the charging are prevented by computing an apparatus SOC and reporting the SOC to the HVECU. The apparent SOC is computed by increasing the value of SOC in accordance with the magnitude of the capacity variation. The thus-computed apparent SOC is reported to the HVECU by the battery ECU, so that it can be determined that the control center value has been exceeded. Thus, it becomes possible to provide battery control apparatus, method and program and a battery control system for a battery pack which are capable of controlling the charging/discharging of the battery pack with an improved accuracy despite capacity variation.

Claims

1. A battery pack charge/discharge control apparatus for controlling a charge/discharge of a battery pack that is formed by combining a plurality of unit batteries of a secondary battery type, comprising:

a battery ECU, the battery ECU, comprising;

a charge/discharge restriction device for restricting the charge/discharge based on at least one of a capacity upper limit value and a capacity lower limit value of the unit batteries constituting the battery pack;

a remaining capacity detection device for detecting remaining capacities of unit batteries constituting the battery pack;

a control value computation device for computing a control state-of-charge value based on at least one of a minimum value and a maximum value of the detected remaining capacities;

a capacity difference computation device for computing, as a capacity difference, a remaining capacity difference between the remaining capacity of a first unit battery and the remaining capacity of a second unit battery among the unit batteries whose remaining capacities have been detected, the remaining capacity of the second unit battery being less than the remaining capacity of the first unit battery;

a storage device for storing a correlation between the capacity difference and an apparent state-of-charge value that is different from the control state-of-charge value;

an apparent state-of-charge value computation device for computing an apparent state-of-charge value with reference to the correlation based on the capacity difference; and

an apparent state-of-charge value adoption device for adopting the apparent state-of-charge value if the capacity difference is at least a predetermined capacity difference that is stored beforehand,

wherein the correlation is expressed by Mathematical Expression (1);

2. A battery pack charge/discharge control apparatus for controlling a charge/discharge of a battery pack that is formed by combining a plurality of unit batteries of a secondary battery type, comprising:

a battery ECU, the battery ECU, comprising;

a charge/discharge restriction device for restricting the charge/discharge based on at least one of a capacity upper limit value and a capacity lower limit value of the unit batteries constituting the battery pack;

a remaining capacity detection device for detecting remaining capacities of unit batteries constituting the battery pack;

a control value computation device for computing a control state-of-charge value based on at least one of a minimum value and a maximum value of the detected remaining capacities;

a capacity difference computation device for computing, as a capacity difference, a remaining capacity difference between the remaining capacity of a first unit battery and the remaining capacity of a second unit battery among the unit batteries whose remaining capacities have been detected, the remaining capacity of the second unit battery being less than the remaining capacity of the first unit battery;

a storage device for storing a correlation between the capacity difference and an apparent state-of-charge value that is different from the control state-of-charge value;

an apparent state-of-charge value computation device for computing an apparent state-of-charge value with reference to the correlation based on the capacity difference; and

an apparent state-of-charge value adoption device for adopting the apparent state-of-charge value if the capacity difference is at least a predetermined capacity difference that is stored beforehand,

wherein the correlation is expressed by Mathematical Expression (1);

3. A battery pack charge/discharge control apparatus for controlling a charge/discharge of a battery pack that is formed by combining a plurality of unit batteries of a secondary battery type, comprising:

a battery ECU, the battery ECU, comprising;

a charge/discharge restriction device for restricting the charge/discharge based on at least one of a capacity upper limit value and a capacity lower limit value of the unit batteries constituting the battery pack;

a remaining capacity detection device for detecting remaining capacities of unit batteries constituting the battery pack;

a control value computation device for computing a control state-of-charge value based on at least one of a minimum value and a maximum value of the detected remaining capacities;

a capacity difference computation device for computing, as a capacity difference, a remaining capacity difference between the remaining capacity of a first unit battery and the remaining capacity of a second unit battery among the unit batteries whose remaining capacities have been detected, the remaining capacity of the second unit battery being less than the remaining capacity of the first unit battery;

a storage device for storing a correlation between the capacity difference and an apparent state-of-charge value that is different from the control state-of-charge value;

an apparent state-of-charge value computation device for computing an apparent state-of-charge value with reference to the correlation based on the capacity difference; and

an apparent state-of-charge value adoption device for adopting the apparent state-of-charge value if the capacity difference is at least a predetermined capacity difference that is stored beforehand,

wherein the correlation is expressed by Mathematical Expression (1);

4. A battery pack charge/discharge control apparatus for controlling a charge/discharge of a battery pack that is formed by combining a plurality of unit batteries of a secondary battery type, comprising:

a battery ECU, the battery ECU, comprising;

a charge/discharge restriction device for restricting the charge/discharge based on at least one of a capacity upper limit value and a capacity lower limit value of the unit batteries constituting the battery pack;

a remaining capacity detection device for detecting remaining capacities of unit batteries constituting the battery pack;

a control value computation device for computing a control state-of-charge value based on at least one of a minimum value and a maximum value of the detected remaining capacities;

a capacity difference computation device for computing, as a capacity difference, a remaining capacity difference between the remaining capacity of a first unit battery and the remaining capacity of a second unit battery among the unit batteries whose remaining capacities have been detected, the remaining capacity of the second unit battery being less than the remaining capacity of the first unit battery;

a storage device for storing a correlation between the capacity difference and an apparent state-of-charge value that is different from the control state-of-charge value;

an apparent state-of-charge value computation device for computing an apparent state-of-charge value with reference to the correlation based on the capacity difference; and

an apparent state-of-charge value adoption device for adopting the apparent state-of-charge value if the capacity difference is at least a predetermined capacity difference that is stored beforehand,

wherein the correlation is expressed by Mathematical Expression (1);

5. A battery pack charge/discharge control apparatus for controlling a charge/discharge of a battery pack that is formed by combining a plurality of unit batteries of a secondary battery type, comprising:

a remaining capacity detector that detects remaining capacities of unit batteries constituting the battery pack; and

a controller that restricts the charge/discharge based on at least one of a capacity upper limit value and a capacity lower limit value of the unit batteries constituting the battery pack, computes a control state-of-charge value based on at least one of a minimum value and a maximum value of the detected remaining capacities, computes as a capacity difference, a remaining capacity difference between the remaining capacity of a first unit battery and the remaining capacity of a second unit battery among the unit batteries whose remaining capacities have been detected, the remaining capacity of the second unit battery being less than the remaining capacity of the first unit battery, stores a correlation between the capacity difference and an apparent state-of-charge value that is different from the control state-of-charge value, computes an apparent state-of-charge value with reference to the correlation based on the capacity difference, and the controller adopts the apparent state-of-charge value if the capacity difference is at least a predetermined capacity difference that is stored beforehand,

wherein the correlation is expressed by Mathematical Expression (1);

6. A battery pack charge/discharge control apparatus for controlling a charge/discharge of a battery pack that is formed by combining a plurality of unit batteries of a secondary battery type, comprising:

a remaining capacity detector that detects remaining capacities of unit batteries constituting the battery pack; and

a controller that restricts the charge/discharge based on at least one of a capacity upper limit value and a capacity lower limit value of the unit batteries constituting the battery pack, computes a control state-of-charge value based on at least one of a minimum value and a maximum value of the detected remaining capacities, computes as a capacity difference, a remaining capacity difference between the remaining capacity of a first unit battery and the remaining capacity of a second unit battery among the unit batteries whose remaining capacities have been detected, the remaining capacity of the second unit battery being less than the remaining capacity of the first unit battery, stores a correlation between the capacity difference and an apparent state-of-charge value that is different from the control state-of-charge value, computes an apparent state-of-charge value with reference to the correlation based on the capacity difference, and the controller adopts the apparent state-of-charge value if the capacity difference is at least a predetermined capacity difference that is stored beforehand,

wherein the correlation is expressed by Mathematical Expression (1);

7. A battery pack charge/discharge control apparatus for controlling a charge/discharge of a battery pack that is formed by combining a plurality of unit batteries of a secondary battery type, comprising:

a remaining capacity detector that detects remaining capacities of unit batteries constituting the battery pack; and

a controller that restricts the charge/discharge based on at least one of a capacity upper limit value and a capacity lower limit value of the unit batteries constituting the battery pack, computes a control state-of-charge value based on at least one of a minimum value and a maximum value of the detected remaining capacities, computes as a capacity difference, a remaining capacity difference between the remaining capacity of a first unit battery and the remaining capacity of a second unit battery among the unit batteries whose remaining capacities have been detected, the remaining capacity of the second unit battery being less than the remaining capacity of the first unit battery, stores a correlation between the capacity difference and an apparent state-of-charge value that is different from the control state-of-charge value, computes an apparent state-of-charge value with reference to the correlation based on the capacity difference, and the controller adopts the apparent state-of-charge value if the capacity difference is at least a predetermined capacity difference that is stored beforehand,

wherein the correlation is expressed by Mathematical Expression (1);

8. A battery pack charge/discharge control apparatus for controlling a charge/discharge of a battery pack that is formed by combining a plurality of unit batteries of a secondary battery type, comprising:

a remaining capacity detector that detects remaining capacities of unit batteries constituting the battery pack; and

a controller that restricts the charge/discharge based on at least one of a capacity upper limit value and a capacity lower limit value of the unit batteries constituting the battery pack, computes a control state-of-charge value based on at least one of a minimum value and a maximum value of the detected remaining capacities, computes as a capacity difference, a remaining capacity difference between the remaining capacity of a first unit battery and the remaining capacity of a second unit battery among the unit batteries whose remaining capacities have been detected, the remaining capacity of the second unit battery being less than the remaining capacity of the first unit battery, stores a correlation between the capacity difference and an apparent state-of-charge value that is different from the control state-of-charge value, computes an apparent state-of-charge value with reference to the correlation based on the capacity difference, and the controller adopts the apparent state-of-charge value if the capacity difference is at least a predetermined capacity difference that is stored beforehand,

wherein the correlation is expressed by Mathematical Expression (1);