BATTERY MANAGEMENT SYSTEM AND METHOD OF DYNAMICALLY ALLOCATING CHARGING CURRENT

• US 20120078435A1
• Filed: 03/24/2011
• Published: 03/29/2012
• Est. Priority Date: 09/24/2010
• Status: Active Grant

• Current Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Inventors: HUO, WEI, YIN, HUI, LIN, BO-CHING, GENG, YAN-LING, XU, YAN, LI, YONG-YONG
• Granted Patent: US 8,791,670 B2
• Time in Patent Office: Days
• US Class Current: 700/297
• CPC Class Codes: H02J 2310/58 The condition being electrical
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• 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: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving

Abstract

A battery management system includes a power converter, a first switch, a second switch, a first detecting unit, and a CPU. The power converter is configured to divide current provided by the power supply into a first and a second output current, according to a working current of a system load in a normal state, the first output current is used to power the system load, and the second output current is used to charge a battery unit. The CPU is configured to determine whether the value of current detected by the first detecting unit is greater than a threshold value, and further controls turning on the first switch to power the system load using the first output current, and turn on the second switch to charge the battery unit using the second output current.

Claims

1. A battery management system, comprising:

a system load;

a battery unit;

a power converter for being connected to a power supply, configured to divide current provided by the power supply into two output currents, according to a working current of the system load in a normal state, wherein a first output current is used to power the system load, and a second output current is used to charge the battery unit;

a first switch;

a second switch;

a first detecting unit connected to the input of the power converter, configured to detect the current which is provided by the power supply; and

a CPU, configured to determine whether the value of the current detected by the first detecting unit is greater than a threshold value, and further controls to turn on the first switch to power the system load by the first output current, and turn on the second switch to charge the battery unit by the second output current if yes.

2. The battery management system as recited in claim 1, wherein the current threshold is a current used to normally power the system load.

3. The battery management system as recited in claim 1, wherein a maximum value of the current charging the battery unit is set to equal to the maximum value of the current provided by the power supply, and the value of the first output current is changes with the demand of the system load, and the value of the second output current is varies inversely with changes in the first output current.

4. The battery management system as recited in claim 1, further comprising a second detecting unit configured to detect the second output current.

5. The battery management system as recited in claim 4, wherein when the value of the second output current detected by the second detecting unit is less than a cut-off current value of the battery unit, and the current value detected by the first detecting unit is less than the maximum current value provided by the power supply at the same time determined by the CPU, the CPU determines the process of charging the battery unit to be finished, and controls to turn off the second switch.

6. The battery management system as recited in claim 1, wherein when the value of the current provided by the power supply is less than the threshold value, the CPU is further configured to turn off the first switch and second switch.

7. The battery management system as recited in claim 1, wherein when the second switch is turned to forward conduction, the second output current provided is used to charge the battery unit, and when the second switch is turned to opposite conduction, the current provided by the battery unit is used to power the system load.

8. The battery management system as recited in claim 7, wherein when the value of the second output current decreases to zero at one moment, the CPU determines the system load is drawing all the provided by the power supply, then controls the second switch to turn to forward conduction, and the battery unit can provide additional current to power the system load as an auxiliary power supply.

9. A method capable of dynamically allocating charging current implemented by a battery management system, wherein the battery management system comprising a power supply, a battery unit, a system load, a first switch and a second switch, wherein the second switch can turn to a forward conduction and a opposite conduction, the method comprising:

determining whether the value of the current provided by the power supply is greater than a threshold value;

controlling to turn on the first switch and turn the second switch to the forward conduction when the value is greater than the threshold value; and

dividing the current provided by the power supply into a first output current and a second output current according to a working current of the system load in a normal state, wherein the first output current is used to power the system load, and the second output current is used to charge the battery unit, and the value of the second output current is changed with the variation value of the first output current.

10. The method as recited in claim 9, further comprising:

determining whether the value of the second output current is less than a cut-off current value of the battery unit;

determining whether the current value is less than a maximum current value provided by the power supply when the second output current value is less than the cut-off current value; and

determining the process of charging the battery unit to be finished, and turning off the second switch.

11. The method as recited in claim 9, wherein when the second switch is turned to forward conduction, the second output current provided by the power supply is used to charge the battery unit, and when the second switch is turned to opposite conduction, the current provided by the battery unit is used to power the system load.

12. The method as recited in claim 9, further comprising:

determining whether the value of the second output current decreases to zero; and

controlling the second switch to turn to opposite conduction, and the battery unit provides current to the system load when the second output current value is zero.