ELECTRICAL STORAGE SYSTEM

• US 20160380450A1
• Filed: 12/10/2014
• Published: 12/29/2016
• Est. Priority Date: 12/11/2013
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: MANO, Ryo, ISHISHITA, Teruo
• Granted Patent: US 10,283,980 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection

Abstract

When a voltage value of an electrical storage device becomes higher than a predetermined voltage value for identifying an overcharged state of the electrical storage device, calculation of a heat generation amount of the electrical storage device based on a current value is started. When the calculated heat generation amount is larger than a predetermined amount, it is determined that the electrical storage device is in an abnormal state (abnormal state related to heating). Because the electrical storage device enters an easily heated state when the voltage value becomes higher than the predetermined voltage value, the heat generation amount may be monitored by starting calculation of the heat generation amount. Once the voltage value becomes higher than the predetermined voltage value, irrespective of a high/low relationship between the voltage value and the predetermined voltage value, the abnormal state may be determined by monitoring the heat generation amount.

Claims

1. An electrical storage system comprising:

an electrical storage device;

a voltage sensor configured to detect a voltage value of the electrical storage device;

a current sensor configured to detect a current value of the electrical storage device; and

a controller configured to

(a) start calculation of a heat generation amount of the electrical storage device based on the current value, when the voltage value becomes higher than a predetermined voltage value and

(b) determine that the electrical storage device is in an abnormal state, when the calculated heat generation amount is larger than a predetermined amount, the predetermined voltage value being used to identify an overcharged state of the electrical storage device, the abnormal state being an abnormal state related to heating of the electrical storage device.

2. The electrical storage system according to claim 1, wherein

the controller is configured to calculate the heat generation amount in a period during which the voltage value becomes higher than the predetermined voltage value and then becomes lower than or equal to the predetermined voltage value and a duration of the voltage value lower than or equal to the predetermined voltage value reaches a predetermined time.

3. The electrical storage system according to claim 1, wherein

the controller is configured to set the calculated heat generation amount to zero when the voltage value becomes higher than the predetermined voltage value and then becomes lower than or equal to the predetermined voltage value and a duration of the voltage value lower than or equal to the predetermined voltage value is longer than or equal to a predetermined time.

8. The electrical storage system according to claim 2, wherein

the controller is configured to set the calculated heat generation amount to zero when the voltage value becomes higher than the predetermined voltage value and then becomes lower than or equal to the predetermined voltage value and a duration of the voltage value lower than or equal to the predetermined voltage value is longer than or equal to the predetermined time.

4. An electrical storage system comprising:

an electrical storage device;

a voltage sensor configured to detect a voltage value of the electrical storage device; and

a controller configured to

(a) calculate a heat generation amount of the electrical storage device in a period during which the voltage value changes from a state where the voltage value falls within a first region to a state where the voltage value falls within a second region and a duration of the voltage value that falls within the second region reaches a predetermined time, and

(b) determine that the electrical storage device is in an abnormal state, when the heat generation amount is larger than a predetermined amount,

the first region including the voltage value higher than a predetermined voltage value, the second region including the voltage value lower than the predetermined voltage value, and the predetermined voltage value being used to identify an overcharged state of the electrical storage device.

5. The electrical storage system according to claim 4, wherein

the controller is configured to set the heat generation amount of the electrical storage device to zero, when the duration of the voltage value that falls within the second region is longer than or equal to the predetermined time.

6. The electrical storage system according to claim 4, further comprising:

a current sensor configured to detect a current value of the electrical storage device, wherein

the controller is configured to calculate the heat generation amount based on the current value.

7. The electrical storage system according to claim 5, further comprising:

a current sensor configured to detect a current value of the electrical storage device, wherein

the controller is configured to calculate the heat generation amount based on the current value.