Apparatus and methodology for battery backup circuit and control in an uninterruptible power supply

• US 9,490,663 B1
• Filed: 07/16/2012
• Issued: 11/08/2016
• Est. Priority Date: 07/16/2012
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Kim, Sangsun, Krieger, Ken
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Shiao, David
• Application Number:
  US13/550,054
• Time in Patent Office: 1,576 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: H02J 9/062 for AC powered loads

Abstract

Systems and methods for providing an uninterruptible power supply are disclosed herein. The system includes a power converter component that concurrently provides power to a load and charges a battery by using a primary power source. The system also includes a backup component that delivers power from the battery to the load during a primary power failure. Additionally, a set of series transistors are coupled to the battery to control charging current and discharging current of the battery.

Claims

1. A system configured to provide an uninterruptible power supply, comprising:

a power converter component that concurrently provides power to a load and charges a battery by using a primary power source;

a backup-charger component, including;

a first power storage element coupled to an output of the power converter component and a protection component;

a second power storage element coupled in parallel with the battery and the protection component;

a backup device that is coupled to the battery and the power converter component, the backup device including a voltage converter and being configured to provide power from the battery to a load when a primary power failure is detected in the power converter component, wherein the second power storage element is coupled to the backup device, the backup device controllably delivers power from the battery to the load when a primary power failure is detected in the power converter component, and

a charging device that is coupled to the backup device, the battery, the power converter component, the protection component, and the first power storage element and configured to charge the battery from power provided by the power converter component, wherein the first power storage element coupled to the charging device stores a portion of power supplied by the power converter component to vary a rate of transfer of power supplied by the power converter component to the battery; and

the protection component, including a set of serially connected transistors coupled in series to the battery that controls charging current and discharging current of the battery by operating in a linear region of the transistors.

2. The system of claim 1, wherein the set of transistors form a bi-directional switch.

3. The system of claim 1, wherein the backup device and the set of transistors provide redundancy for disconnecting the battery from the load.

4. The system of claim 1, wherein the backup device is a buck converter.

5. The system of claim 1, wherein the backup device is a buck-boost converter.

6. The system of claim 1, wherein a control component turns off the set of transistors during a fault condition.

7. The system of claim 1, wherein the set of transistors is coupled to a sensing component configured to sense charging current and discharging current of the battery.

8. The system of claim 1, wherein the power converter component generates a signal in response to the primary power failure.

9. The system of claim 1, wherein the set of transistors and the load are coupled to a common terminal.

10. The system of claim 1, wherein the backup device implements a pulse width modulation (PWM) technique to controllably deliver the power to the load.

11. The system of claim 1, wherein the set of transistors allow the battery to be disconnected from the load.

12. The system of claim 1, wherein the backup device regulates voltage delivered from the battery to the load.

13. The system of claim 1, wherein the set of transistors and the backup device are coupled to a common terminal.

14. A method for supplying uninterruptible power, comprising:

converting primary power into direct current (DC) power by a power converter component that concurrently provides power to a load and charges a battery by using a primary power source;

using a component including

a first power storage element coupled to an output of the power converter component and a protection component;

a second power storage element coupled in parallel with the battery and the protection component;

a backup component that is coupled to the battery and the power converter component, the backup component including a voltage converter and being configured to provide power from the battery to a load when a primary power failure is detected in the power converter component, and

a charger component that is coupled to the backup component, the battery, the power converter component, the protection component, and the first power storage element and configured to charge the battery from power provided by the power converter component,

the protection component including a set of serially connected transistors coupled in series to the battery,

controlling a rate for delivering the DC power to the battery by operating in a linear region of a first transistor in the set of transistors and using a portion of the DC power stored in the second power storage element to deliver the DC power to the battery;

using stored DC power in the second power storage element to drive the load upon unavailability of the primary power; and

controlling a rate for powering the load by operating in a linear region of a second transistor in the set of transistors.

15. The method of claim 14, further comprising:

turning off the set of transistors to disconnect the battery from the load in response to an occurrence of a fault condition.

16. The method of claim 14, wherein the controlling the rate for delivering the DC power to the battery includes sensing a charging current.

17. The method of claim 16, further comprising:

opening the set of transistors in response to a determination that the sensed charging current is above a threshold value.

18. A power supply, comprising:

a power converter component that concurrently provides power to a load and charges a battery by using a primary power source;

a component, including;

a first power storage element coupled to an output of the power converter component and a protection component;

a second power storage element coupled in parallel with the battery and the protection component;

a backup component that is coupled to the battery and the power converter component, the backup component including a voltage converter and being configured to provide power from the battery to a load when a primary power failure is detected in the power converter component,

wherein the second power storage element coupled to the backup component controllably delivers power from the battery to the load when a primary power failure is detected in the power converter component, and

a charger component that is coupled to the backup component, the battery, the power converter component, the protection component, and the first power storage element and configured to charge the battery from power provided by the power converter component,

wherein the first power storage element coupled to the charger component stores a portion of power supplied by the power converter component to vary a rate of transfer of power supplied by the power converter component to the battery; and

the protection component including a set of metal-oxide-semiconductor field-effect transistors (MOSFETs) connected in series and coupled in series to the battery that control charging current and discharging current of the battery by operating in a linear region of the MOSFETs; and

a control component that disconnects the battery from the load during a fault condition via the set of MOSFETs.