Charge/discharge control device for secondary battery and vehicle equipped with the same

• US 8,098,050 B2
• Filed: 11/21/2007
• Issued: 01/17/2012
• Est. Priority Date: 11/28/2006
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Takahashi, Hidenori
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): Omar, Ahmed
• Application Number:
  US12/513,999
• Publication Number:
  US 20100001692A1
• Time in Patent Office: 1,518 Days
• Field of Search: 320/150
• US Class Current: 320/150
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/246 Temperature
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/14 : for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries

Abstract

A charge/discharge control device for a secondary battery mounted on a vehicle includes a temperature sensor detecting a temperature of a battery and a control device setting a battery power charged to and discharged from the battery base on the temperature detected by the temperature sensor and the state of charge of the battery. The control device sets at least one of a first value, a second value and a third value to be increased as the battery temperature rises, the first value indicating the state of charge at the time of switching between charging and discharging of the battery, the second value indicating the state of charge at the time when the battery power charged to the battery reaches a limit value in the case where the state of charge falls below the first value, and the third value indicating the state of charge at the time when the battery power discharged from the battery reaches the limit value in the case where the state of charge exceeds the first value.

Claims

1. A charge/discharge control device for a secondary battery, comprising:

a temperature detecting unit detecting a battery temperature of said secondary battery;

a state-of-charge detecting unit detecting a state of charge of said secondary battery to output a state value indicating said state of charge; and

a setting unit, in a case where said state value falls below a first value corresponding to a threshold value for determining whether charging or discharging of said secondary battery is prioritized, setting a charge power of said secondary battery such that said charge power increases as said state value decreases and a value of said charge power attains a first limit value when said state value reaches a second value, and, in a case where said state value exceeds said first value, setting a discharge power of said secondary battery such that said discharge power increases as said state value increases and a value of said discharge power attains a second limit value when said state value reaches a third value,

said setting unit selecting, based on a distribution of said state value, at least one of said first value, said second value and said third value as an object to be varied which varies in accordance with said battery temperature detected by said temperature detecting unit, and increasing a value of said object to be varied as said battery temperature rises.

2. The charge/discharge control device for a secondary battery according to claim 1, wherein said setting unit selects said second value as said object to be varied when a frequency in which said state value is smaller than said first value is higher than a frequency in which said state value is larger than said first value, and selects said third value as said object to be varied when a frequency in which said state value is larger than said first value is higher than a frequency in which said state value is smaller than said first value.

3. The charge/discharge control device for a secondary battery according to claim 1, wherein said setting unit selects said first value as said object to be varied when switching between charging and discharging of said secondary battery is repeated a predetermined number of times or more within a predetermined period of time.

4. The charge/discharge control device for a secondary battery according to claim 1, wherein said secondary battery includes a lithium-ion battery.

5. A vehicle comprising:

a secondary battery; and

a charge/discharge control device for said secondary battery,

said charge/discharge control device including

a temperature detecting unit detecting a battery temperature of said secondary battery,

a state-of-charge detecting unit detecting a state of charge of said secondary battery to output a state value indicating said state of charge, and

a setting unit, in a case where said state value falls below a first value corresponding to a threshold value for determining whether charging or discharging of said secondary battery is prioritized, setting a charge power of said secondary battery such that said charge power increases as said state value decreases and a value of said charge power attains a first limit value when said state value reaches a second value, and, in a case where said state value exceeds said first value, setting a discharge power of said secondary battery such that said discharge power increases as said state value increases and a value of said discharge power attains a second limit value when said state value reaches a third value,

said setting unit selecting, based on a distribution of said state value, at least one of said first value, said second value and said third value as an object to be varied which varies in accordance with said battery temperature detected by said temperature detecting unit, and increasing said object to be varied as said battery temperature rises.

6. The vehicle according to claim 5, wherein said setting unit selects said second value as said object to be varied when a frequency in which said state value is smaller than said first value is higher than a frequency in which said state value is larger than said first value, and selects said third value as said object to be varied when a frequency in which said state value is larger than said first value is higher than a frequency in which said state value is smaller than said first value.

7. The vehicle according to claim 5, wherein said setting unit selects said first value as said object to be varied when switching between charging and discharging of said secondary battery is repeated a predetermined number of times or more within a predetermined period of time.

8. The vehicle according to claim 5, wherein said secondary battery includes a lithium-ion battery.

9. A charge/discharge control device for a secondary battery, comprising:

a temperature detecting unit detecting a battery temperature of said secondary battery;

a state-of-charge detecting unit detecting a state of charge of said secondary battery; and

a setting unit setting a battery power charged to and discharged from said secondary battery, based on said battery temperature detected by said temperature detecting unit and said state of charge detected by said state-of-charge detecting unit,

said setting unit, based on a distribution of a value of said state of charge detected by said state-of-charge detecting unit, selecting at least one of a first value, a second value and a third value as a value of an object to be set which is set to be increased as said battery temperature rises, said first value indicating said state of charge at a time of switching between charging and discharging of said secondary battery, said second value indicating said state of charge at a time when said battery power charged to said secondary battery reaches a limit value in a case where said state of charge falls below said first value, and said third value indicating said state of charge at a time when said battery power discharged from said secondary battery reaches the limit value in a case where said state of charge exceeds said first value; and

setting said battery power based on said first to third values and said state of charge detected by said state-of-charge detecting unit.

10. The charge/discharge control device for a secondary battery according to claim 9, wherein said setting unit selects said second value as the value of said object to be set when a frequency in which said state of charge is smaller than said first value is higher than a frequency in which said state of charge is larger than said first value, and selects said third value as the value of said object to be set when a frequency in which said state of charge is larger than said first value is higher than a frequency in which said state of charge is smaller than said first value.

11. The charge/discharge control device for a secondary battery according to claim 9, wherein said setting unit selects said first value as the value of said object to be set when switching between charging and discharging of said secondary battery is repeated a predetermined number of times or more within a predetermined period of time.

12. The charge/discharge control device for a secondary battery according to claim 9, wherein said secondary battery includes a lithium-ion battery.

13. A vehicle comprising:

a secondary battery; and

a charge/discharge control device for said secondary battery,

said charge/discharge control device including

a temperature detecting unit detecting a battery temperature of said secondary battery,

a state-of-charge detecting unit detecting a state of charge of said secondary battery, and

a setting unit setting a battery power charged to and discharged from said secondary battery, based on said battery temperature detected by said temperature detecting unit and said state of charge detected by said state-of-charge detecting unit, said setting unit, based on a distribution of a value of said state of charge detected by said state-of-charge detecting unit, selecting at least one of a first value, a second value and a third value as a value of an object to be set which is set to be increased as said battery temperature rises, said first value indicating said state of charge at a time of switching between charging and discharging of said secondary battery, said second value indicating said state of charge at a time when said battery power charged to said secondary battery reaches a limit value in a case where said state of charge falls below said first value, and said third value indicating said state of charge at a time when said battery power discharged from said secondary battery reaches the limit value in a case where said state of charge exceeds said first value; and

setting said battery power based on said first to third values and said state of charge detected by said state-of-charge detecting unit.

14. The vehicle according to claim 13, wherein said setting unit selects said second value as the value of said object to be set when a frequency in which said state of charge is smaller than said first value is higher than a frequency in which said state of charge is larger than said first value, and selects said third value as the value of said object to be set when a frequency in which said state of charge is larger than said first value is higher than a frequency in which said state of charge is smaller than said first value.

15. The vehicle according to claim 13, wherein said setting unit selects said first value as the value of said object to be set when switching between charging and discharging of said secondary battery is repeated a predetermined number of times or more within a predetermined period of time.

16. The vehicle according to claim 13, wherein said secondary battery includes a lithium-ion battery.