Electric storage system

• US 9,973,018 B2
• Filed: 11/28/2014
• Issued: 05/15/2018
• Est. Priority Date: 12/18/2013
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Suzuki, Yusuke
• Primary Examiner(s): Kik, Phallaka
• Application Number:
  US15/022,034
• Publication Number:
  US 20160233693A1
• Time in Patent Office: 1,264 Days
• Field of Search: 320134, 320136, 320152, 320159, 320162, 320166
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• 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 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• 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 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A reference voltage value is calculated by using a current value, a voltage value, and an internal resistance value of an electric storage apparatus. A dischargeable electric power is calculated by using the reference voltage value and a predetermined internal resistance value previously set to be higher than the internal resistance value. The dischargeable electric power is set as an allowable discharge electric power when temporarily increasing the discharge electric power required of the electric storage apparatus. The reference voltage value is calculated from the internal resistance value and is a fixed value regardless of the relationship between the current value and the voltage value. The dischargeable electric power is also constant. Since the predetermined internal resistance value is higher than the internal resistance value, the dischargeable electric power can be set while the deterioration of the electric storage apparatus is taken into account.

Claims

1. An electric storage system comprising:

a voltage sensor detecting a voltage value of an electric storage apparatus;

a current sensor detecting a current value of the electric storage apparatus; and

a controller setting an allowable discharge electric power serving as an upper limit electric power to which discharge of the electric storage apparatus is allowed,

wherein the controller uses the detected voltage value, the detected current value, and a present internal resistance value of the electric storage apparatus that is calculated based on the detected voltage value and the detected current value, to calculate a reference voltage value, the reference voltage value being the voltage value when no current flows,

the controller uses the reference voltage value and a predetermined internal resistance value to calculate a dischargeable electric power, the predetermined internal resistance value being previously set to be higher than the present internal resistance value, the dischargeable electric power being an electric power when a discharge electric power of the electric storage apparatus is increased to cause the voltage value to reach a lower limit voltage value, and

the controller sets the dischargeable electric power as the allowable discharge electric power when temporarily increasing the discharge electric power required of the electric storage apparatus.

2. The electric storage system according to claim 1, wherein the controller calculates the dischargeable electric power based on the following expression (I):

3. The electric storage system according to claim 1, wherein the controller corrects the present internal resistance value to a value lower than the present internal resistance value at present in calculating the present resistance value to calculate the dischargeable electric power during discharge of the electric storage apparatus.

4. The electric storage system according to claim 1, wherein the controller corrects the present internal resistance value to a value higher than the present internal resistance value in calculating the present internal resistance value to calculate the dischargeable electric power during charge of the electric storage apparatus.

5. The electric storage system according to claim 1, wherein the controller uses the present internal resistance value instead of the predetermined internal resistance value to calculate the dischargeable electric power when the present internal resistance value is higher than the predetermined internal resistance value.

6. An electric storage system comprising:

a voltage sensor detecting a voltage value of an electric storage apparatus;

a current sensor detecting a current value of the electric storage apparatus; and

a controller setting an allowable charge electric power serving as an upper limit electric power to which charge of the electric storage apparatus is allowed,

wherein the controller uses the detected voltage value, the detected current value, and a present internal resistance value of the electric storage apparatus that is calculated based on the detected voltage value and the detected current value, to calculate a reference voltage value, the reference voltage value being the voltage value when no current flows,

the controller uses the reference voltage value and a predetermined internal resistance value to calculate a chargeable electric power, the predetermined internal resistance value being previously set to be higher than the present internal resistance value, the chargeable electric power being an electric power when a charge electric power of the electric storage apparatus is increased to cause the voltage value to reach an upper limit voltage value, and

the controller sets the chargeable electric power as the allowable charge electric power when temporarily increasing the charge electric power required of the electric storage apparatus.

7. The electric storage system according to claim 6, wherein the controller calculates the chargeable electric power based on the following expression (II):

8. The electric storage system according to claim 6, wherein the controller corrects the present internal resistance value to a value higher than the present internal resistance value in calculating the present internal resistance value to calculate the chargeable electric power during discharge of the electric storage apparatus.

9. The electric storage system according to claim 6, wherein the controller corrects the present internal resistance value to a value lower than the present internal resistance value in calculating the present internal resistance value to calculate the chargeable electric power during charge of the electric storage apparatus.

10. The electric storage system according to claim 6, wherein the controller uses the present internal resistance value instead of the predetermined internal resistance value to calculate the chargeable electric power when the present internal resistance value is higher than the predetermined internal resistance value.