Method and apparatus of controlling for charging/discharging voltage of battery

• US 20060284614A1
• Filed: 06/14/2006
• Published: 12/21/2006
• Est. Priority Date: 06/14/2005
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Jung, Do Yang, Kim, Do Youn
• Granted Patent: US 7,683,579 B2
• Time in Patent Office: Days
• US Class Current: 324/149
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters

Abstract

Disclosed is an apparatus and method for controlling the discharge or charge power of a battery, capable of preventing over-charge and over-discharge of battery cells according to states of the battery cells, and solving a problem that the lifetime of a conventional battery pack is rapidly reduced due to the over-charge or over-discharge of some cells of the battery pack. The method includes the steps of estimating the maximum power of the battery, measuring voltage of a battery cell or pack, checking whether or not the voltage of the battery cell or pack deviates from a preset limited range so as to correspond to the maximum power, and when the voltage of the battery cell or pack deviates from a preset limited range, controlling the discharge or charge power of the battery.

Claims

1. A method for controlling the discharge or charge power of a battery, the method comprising the steps of:

estimating the maximum power of the battery;

measuring voltage of a battery cell or pack;

checking whether or not the voltage of the battery cell or pack deviates from a preset limited range so as to correspond to the maximum power; and

when the voltage of the battery cell or pack deviates from a preset limited range, controlling the discharge or charge power of the battery.

2. The method according to claim 1, wherein the maximum power of the battery is calculated by a following equation approximated from the correlation between:

a state of charge (SOC) of the battery, and the maximum charge and discharge power of the battery; and

temperature, and the maximum power of the battery,

3. The method according to claim 1, wherein the step of controlling the discharge or charge power of the battery comprises the sub-steps of:

when at least one of the measured voltages is higher than the voltage of the preset limited range, decreasing available charge and discharge power of the battery pack; and

when at least one of the measured voltages is lower than the voltage of the preset limited range, increasing the available charge and discharge power of the battery pack.

4. A battery control apparatus comprising:

a temperature sensor;

a state of charge (SOC) estimator for estimating an SOC of a battery;

a voltmeter for measuring voltage of a battery cell or pack; and

a controller for;

estimating the maximum power of the battery using the temperature and the SOC;

measuring the voltage of the battery cell or pack by means of the voltmeter;

checking whether or not the voltage of the battery cell or pack deviates from a preset limited range so as to correspond to the maximum power; and

when the voltage of the battery cell or pack deviates from a preset limited range, controlling discharge or charge power of the battery.

5. The battery control apparatus according to claim 4, wherein the maximum power of the battery is calculated by a following equation approximated from the correlation between:

the SOC of the battery, and the maximum charge and discharge power of the battery; and

the temperature, and the maximum power of the battery,

Power_max=F(SOC,temp,accumulated discharge Ah)F(SOC,temp)×

F(accumulated discharge Ah).

6. The battery control apparatus according to claim 4, wherein the controlling of the discharge or charge power of the battery is performed by:

when at least one of the measured voltages is higher than the voltage of the preset limited range, decreasing available charge and discharge power of the battery pack; and

when at least. one of the measured voltages is lower than the voltage of the preset limited range, increasing the available charge and discharge power of the battery pack.