Apparatus and method for maintaining charge amount of secondary battery

• US 9,716,397 B2
• Filed: 01/24/2014
• Issued: 07/25/2017
• Est. Priority Date: 10/14/2013
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Cho, Tae-Shin, Baek, Seoung-Mun, Chung, Dae-Sik, Cho, Young-Bo
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US14/439,495
• Publication Number:
  US 20150288198A1
• Time in Patent Office: 1,278 Days
• Field of Search: 320107, 320116, 320132, 320149
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

The present disclosure discloses an apparatus and method for maintaining a charge amount of a secondary battery. The present disclosure reduces a charge amount or increases a discharge amount when a larger charge amount than a required proper charge amount is charged in the secondary battery. Also, the present disclosure reduces a discharge amount or increases a charge amount when a smaller charge amount than a required proper charge amount is charged in the secondary battery. Through this, a proper charge amount may be maintained.

Claims

1. An apparatus for maintaining a charge amount of a secondary battery, the apparatus comprising:

a sensing unit to measure an electrical characteristic value of the secondary battery;

a memory unit to store a charged power amount decrease section and a charged power amount increase section based on the electrical characteristic value of the secondary battery; and

a control unit to output a control signal for reducing an amount of power charged in the secondary battery when a state of the secondary battery corresponds to the charged power amount decrease section based on the electrical characteristic value measured by the sensing unit, and to output a control signal for increasing an amount of power charged in the secondary battery when the state of the secondary battery corresponds to the charged power amount increase section based on the electrical characteristic value measured by the unit,

wherein the charged power amount decrease section is a section where the amount of power charged in the secondary battery is beyond a required charge amount maintenance section,

wherein the charged power amount increase section is a section where the amount of power charged in the secondary battery is below the required charge amount maintenance section, and

wherein when the state of the secondary battery corresponds to the required charge amount maintenance section, the control unit calculates an amount of discharging power of the secondary battery using the electrical characteristic value of the secondary battery measured by the sensing unit during discharging of the secondary battery, and outputs a control signal for charging the secondary battery by an amount of charging power obtained as a result of adding an amount of power compensation to the calculated amount of discharging power when charging the secondary battery.

2. The apparatus for maintaining the charge amount of the secondary battery according to claim 1, wherein the sensing unit corresponds to a voltage measurement sensor.

3. The apparatus for maintaining the charge amount of the secondary battery according to claim 2, wherein the charged power amount decrease section and the charged power amount increase section are set based on a voltage value of the secondary battery.

4. The apparatus for maintaining the charge amount of the secondary battery according to claim 2, wherein the sensing unit further includes a current measurement sensor.

5. The apparatus for maintaining the charge amount of the secondary battery according to claim 4, wherein the charged power amount decrease section and the charged power amount increase section are set based on a state of charge (SOC) of the secondary battery.

6. The apparatus for maintaining the charge amount of the secondary battery according to claim 1, wherein the control signal for reducing the amount of power charged in the secondary battery is a signal for reducing an amount of charging power supplied to the secondary battery.

7. The apparatus for maintaining the charge amount of the secondary battery according to claim 1, wherein the control signal for reducing the amount of power charged in the secondary battery is a signal for increasing an amount of discharging power outputted from the secondary battery.

8. The apparatus for maintaining the charge amount of the secondary battery according to claim 1, wherein the control signal for reducing the amount of power charged in the secondary battery is a signal for reducing an amount of charging power supplied to the secondary battery and increasing an amount of discharging power outputted from the secondary battery.

9. The apparatus for maintaining the charge amount of the secondary battery according to claim 1, wherein the control signal for increasing the amount of power charged in the secondary battery is a signal for reducing an amount of discharging power outputted from the secondary battery.

10. The apparatus for maintaining the charge amount of the secondary battery according to claim 1, wherein the control signal for increasing the amount of power charged in the secondary battery is a signal for increasing an amount of charging power supplied to the secondary battery.

11. The apparatus for maintaining the charge amount of the secondary battery according to claim 1, wherein the control signal for increasing the amount of power charged in the secondary battery is a signal for reducing an amount of discharging power outputted from the secondary battery and increasing an amount of charging power supplied to the secondary battery.

12. The apparatus for maintaining the charge amount of the secondary battery according to claim 1, wherein the memory unit further stores a charging stop section where the amount of power charged in the secondary battery represents a larger amount of power than the charged power amount decrease section, and

the control unit outputs a control signal for stopping the charge of the secondary battery when the state of the secondary battery corresponds to the charging stop section based on the electrical characteristic value measured by the sensing unit.

13. The apparatus for maintaining the charge amount of the secondary battery according to claim 1, wherein the memory unit further stores a discharging stop section where the amount of power charged in the secondary battery represents a smaller amount of power than the charged power amount increase section, and

the control unit outputs a control signal for stopping the discharge of the secondary battery when the state of the secondary battery corresponds to the discharging stop section based on the electrical characteristic value measured by the sensing unit.

14. An energy storage system comprising:

a plurality of secondary batteries;

an apparatus for maintaining a charge amount of a secondary battery according to claim 1; and

a power inverter unit to provide a charging power to the secondary battery or provide a discharging power from the secondary battery to an external power source, in response to a control signal outputted from the control unit included in the apparatus for maintaining the charge amount of the secondary battery.

15. A method for maintaining a charge amount of a secondary battery through an apparatus for maintaining the charge amount of the secondary battery including a sensing unit to measure an electrical characteristic value of the secondary battery, a memory unit to store a charged power amount decrease section and a charged power amount increase section based on the electrical characteristic value of the secondary battery, and a control unit to output a control signal for reducing or increasing an amount of power charged in the secondary battery, the method comprising:

(a) receiving, by the control unit, a signal for the electrical characteristic value of the secondary battery from the sensing unit;

(b) determining, by the control unit, whether a state of the secondary battery corresponds to the charged power amount decrease section or the charged power amount increase section based on the electrical characteristic value of the secondary battery; and

(c) outputting, by the control unit, a control signal for reducing the amount of power charged in the secondary battery when the state of the secondary battery corresponds to the charged power amount decrease section, and outputting a control signal for increasing the amount of power charged in the secondary battery when the state of the secondary battery corresponds to the charged power amount increase section,

wherein the charged power amount decrease section is a section where the amount of power charged in the secondary battery is beyond a required charge amount maintenance section,

wherein the charged power amount increase section is a section where the amount of power charged in the secondary battery is below the required charge amount maintenance section,

wherein the step (b) comprises further determining, by the control unit, whether the state of the secondary battery corresponds to the required charge amount maintenance section based on the electrical characteristic value measured by the sensing unit, and

wherein the step (c) further comprises calculating, by the control unit, an amount of discharging power of the secondary battery using the electrical characteristic value of the secondary battery measured by the sensing unit during discharging of the secondary battery when the state of the secondary battery corresponds to the required charge amount maintenance section, and outputting a control signal for charging the secondary battery by an amount of charging power obtained as a result of adding an amount of power compensation to the calculated amount of discharging power during charging of the secondary battery.