CONTROLLER FOR RECHARGEABLE BATTERY AND TEMPERATURE ESTIMATION METHOD AND DETERIORATION DETERMINATION METHOD FOR RECHARGEABLE BATTERY

• US 20070120537A1
• Filed: 11/29/2006
• Published: 05/31/2007
• Est. Priority Date: 11/30/2005
• Status: Active Grant

• Current Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Original Assignee: Panasonic EV Energy Company, Limited (Toyota Motor Corporation)
• Inventors: YAMAMOTO, Takao
• Granted Patent: US 7,646,176 B2
• Time in Patent Office: Days
• US Class Current: 320/150
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 10/633 characterised by algorithms, flow charts, software details or the like
• CPC Class Codes: H01M 10/6563 with forced flow, e.g. by blowers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A controller for a rechargeable battery and a temperature estimation method and a deterioration determination method for a rechargeable battery enabling an accurate battery temperature to be obtained through calculation. The controller calculates a heat generation amount of Joule heat generated in the rechargeable battery and a heat generation amount of chemical reaction heat generated in the rechargeable battery to calculate the battery temperature of the rechargeable battery based on the calculated Joule heat generation amount and the calculated chemical reaction heat generation amount. When a cooling device is connected to the rechargeable battery, the controller preferably calculates the battery temperature of the rechargeable battery using the Joule heat generation amount, the chemical reaction heat generation amount, and a value indicating the cooling capability of the cooling device.

Claims

1. A controller for a rechargeable battery, the controller comprising:

a calculation unit which when operated calculates a heat generation amount of Joule heat generated in the rechargeable battery and a heat generation amount of chemical reaction heat generated in the rechargeable battery, and calculates a battery temperature of the rechargeable battery using a total heat amount of the Joule heat generation amount and the chemical reaction heat generation amount.

2. The controller according to claim 1, further comprising:

a current measurement unit which measures current value of current when the rechargeable battery is being charged or discharged; and

a storage unit;

wherein the calculation unit calculates the battery temperature and stores the battery temperature in the storage unit at predetermined time intervals, and calculates the chemical reaction heat amount using a latest battery temperature stored in the storage unit and the current value measured by the current measurement unit.

3. The controller according to claim 1, further comprising:

a current measurement unit which measures current value of current when the rechargeable battery is being charged or discharged;

wherein the calculation unit calculates a value of internal resistance of the rechargeable battery, and calculates the Joule heat generation amount using the calculated value of the internal resistance and the current value measured by the current measurement unit.

4. The controller according to claim 3, wherein the calculation unit detects an elapsed time from when direction of the current is switched in the rechargeable battery, corrects the value of the internal resistance in accordance with the detected elapsed time, and calculates the Joule heat generation amount using the corrected value of the internal resistance and the measured current value.

5. The controller according to claim 1, wherein:

the rechargeable battery has a cooling device connected thereto, the cooling device having a predetermined cooling capability for cooling the rechargeable battery; and

the calculation unit calculates the battery temperature of the rechargeable battery using the Joule heat generation amount, the chemical reaction heat generation amount, and a value indicating the cooling capability of the cooling device.

6. The controller according to claim 1, wherein:

the rechargeable battery has a temperature sensor connected thereto, the temperature sensor measuring temperature of the rechargeable battery; and

the calculation unit uses the total heat amount to calculate the battery temperature of the rechargeable battery as a first battery temperature, uses a signal provided from the temperature sensor to determine a second battery temperature of the rechargeable battery, and determines whether the rechargeable battery has deteriorated using the first battery temperature and the second battery temperature.

7. The controller according to claim 6, wherein the calculation unit corrects the total heat amount in accordance with the time required for the heat generated in the rechargeable battery to be conducted to the temperature sensor, and calculates the first battery temperature using the corrected total heat amount.

8. The controller according to claim 1, wherein the rechargeable battery is mounted on a vehicle including an internal combustion engine and a motor functioning as power sources, and the rechargeable battery supplies power to the motor.

9. A method for estimating the temperature of a rechargeable battery, the method comprising:

calculating a heat generation amount of Joule heat generated in the rechargeable battery;

calculating a heat generation amount of chemical reaction heat generated in the rechargeable battery; and

calculating a battery temperature of the rechargeable battery using the total heat amount of the Joule heat generation amount and the chemical reaction heat generation amount.

10. The method according to claim 9, wherein said calculating a heat generation amount of Joule heat, said calculating a heat generation amount of chemical reaction heat, and said calculating a battery temperature of the rechargeable battery are performed at predetermined time intervals, the method further comprising:

measuring current value of current when the rechargeable battery is being charged or discharged; and

storing the calculated battery temperature in a storage unit at the predetermined time intervals;

wherein said calculating a heat generation amount of chemical reaction heat includes calculating the chemical reaction heat amount using a latest battery temperature stored in the storage unit and the measured current value.

11. The method according to claim 9, further comprising:

measuring current value of current when the rechargeable battery is being charged or discharged;

wherein said calculating a heat generation amount of Joule heat includes calculating a value of internal resistance of the rechargeable battery, and calculating the Joule heat generation amount using the calculated value of the internal resistance and the measured current value.

12. The method according to claim 11, wherein said calculating a heat generation amount of Joule heat includes detecting an elapsed time from when direction of the current is switched in the rechargeable battery, correcting the value of the internal resistance in accordance with the detected elapsed time, and calculating the Joule heat generation amount using the corrected value of the internal resistance and the measured current value.

13. The method according to claim 9, wherein:

the rechargeable battery has a cooling device connected thereto, the cooling device having a predetermined cooling capability for cooling the rechargeable battery; and

said calculating a battery temperature of the rechargeable battery includes calculating the battery temperature of the rechargeable battery using the Joule heat generation amount, the chemical reaction heat generation amount, and a value indicating the cooling capability of the cooling device.

14. A method for determining deterioration of a rechargeable battery, the method comprising:

calculating a heat generation amount of Joule heat generated in the rechargeable battery;

calculating a heat generation amount of chemical reaction heat generated in the rechargeable battery;

calculating a first battery temperature of the rechargeable battery using the total heat amount of the Joule heat generation amount and the chemical reaction heat generation amount;

determining a second battery temperature of the rechargeable battery based on a signal provided from a temperature sensor connected to the rechargeable battery; and

determining whether the rechargeable battery has deteriorated using the first battery temperature and the second battery temperature.

15. The method according to claim 14, wherein said calculating a first battery temperature includes correcting the total heat amount in accordance with the time required for the heat generated in the rechargeable battery to be conducted to the temperature sensor, and calculating the first battery temperature using the corrected total heat amount.

16. A computer-readable product encoded with computer-readable program instructions for execution by a computer for estimating the temperature of a rechargeable battery, the program instructions when executed performing steps comprising:

calculating a heat generation amount of Joule heat generated in the rechargeable battery;

calculating a heat generation amount of chemical reaction heat generated in the rechargeable battery; and

calculating a battery temperature of the rechargeable battery using the total heat amount of the Joule heat generation amount and the chemical reaction heat generation amount.

17. The computer-readable product according to claim 16, wherein said calculating a heat generation amount of Joule heat, said calculating a heat generation amount of chemical reaction heat, and said calculating a battery temperature of the rechargeable battery are performed at predetermined time intervals, the program instructions when executed further performing steps comprising:

measuring current value of current when the rechargeable battery is being charged or discharged; and

storing the calculated battery temperature in a storage unit at the predetermined time intervals;

wherein said calculating a heat generation amount of chemical reaction heat includes calculating the chemical reaction heat amount using a latest battery temperature stored in the storage unit and the measured current value.

18. The computer-readable product according to claim 16, wherein the program instructions when executed further performing steps comprising:

measuring current value of current when the rechargeable battery is being charged or discharged;

wherein said calculating a heat generation amount of Joule heat includes calculating a value of internal resistance of the rechargeable battery, and calculating the Joule heat generation amount using the calculated value of the internal resistance and the measured current value.

19. The computer-readable product according to claim 16, wherein:

the rechargeable battery has a cooling device connected thereto, the cooling device having a predetermined cooling capability for cooling the rechargeable battery; and

said calculating a battery temperature of the rechargeable battery includes calculating the battery temperature of the rechargeable battery using the Joule heat generation amount, the chemical reaction heat generation amount, and a value indicating the cooling capability of the cooling device.

20. A computer-readable product encoded with program instructions for execution by a computer for determining deterioration of a rechargeable battery, the program instructions when executed performing steps comprising:

calculating a heat generation amount of Joule heat generated in the rechargeable battery;

calculating a heat generation amount of chemical reaction heat generated in the rechargeable battery;

calculating a first battery temperature of the rechargeable battery using the total heat amount of the Joule heat generation amount and the chemical reaction heat generation amount;

determining a second battery temperature of the rechargeable battery based on a signal provided from a temperature sensor connected to the rechargeable battery; and

determining whether the rechargeable battery has deteriorated using the first battery temperature and the second battery temperature.