Electric system for providing uninterruptible power

• US 20090152951A1
• Filed: 12/18/2007
• Published: 06/18/2009
• Est. Priority Date: 12/18/2007
• Status: Abandoned Application

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Algrain, Marcelo Claudio
• Application Number:
  US12/000,842
• Publication Number:
  US 20090152951A1
• Time in Patent Office: Days
• US Class Current: 307/65
• CPC Class Codes: H02J 9/066 characterised by the use of dynamo-electric machines H02J9/08 takes precedence

Abstract

A power supply system is disclosed. The system may include at least one engine configured to provide a mechanical power output. The system may further include at least one generator operatively coupled to the at least one engine and configured to convert at least a portion of the mechanical power output into an AC electrical power output at a first frequency. The system may further include an uninterruptible power supply electrically coupled to the at least one generator, the uninterruptible power supply having at least one energy storage device configured to store an electrical power. The uninterruptible power supply may further include a power conversion device electrically coupled to the at least one energy storage device and the at least one generator and configured to convert the AC electrical power output at the first frequency and the electrical power stored in the at least one energy storage device to an AC electrical power at a second frequency.

Claims

1. A power supply system, comprising:

at least one engine configured to provide a mechanical power output;

at least one generator operatively coupled to the at least one engine and configured to convert at least a portion of the mechanical power output into an AC electrical power output at a first frequency;

an uninterruptible power supply electrically coupled to the at least one generator, the uninterruptible power supply comprising;

at least one energy storage device configured to store an electrical power; and

a power conversion device electrically coupled to the at least one energy storage device and the at least one generator and configured to convert the AC electrical power output at the first frequency and the electrical power stored in the at least one energy storage device to an AC electrical power at a second frequency.

2. The power supply system of claim 1, wherein the power conversion device is electrically coupled to a primary power source, the primary power source configured to provide a AC electrical power at a third frequency.

3. The power supply system of claim 2, wherein the at least one energy storage device includes at least one battery configured to store DC electrical power.

4. The power supply system of claim 2, wherein the at least one energy storage device is configured to store AC electrical power.

5. The power supply system of claim 3, wherein the power conversion device is further configured to:

receive, from the primary power source, the AC electrical power at the third frequency;

convert the AC electrical power at the third frequency to a DC electrical power; and

store the DC electrical power in the at least one battery.

6. The power supply system of claim 3, wherein the power conversion device is further configured to:

receive, from the at least one generator, the AC electrical power at the first frequency;

convert the AC electrical power at the first frequency to a DC electrical power; and

store the DC electrical power in the at least one battery.

7. The power supply system of claim 4, wherein the power conversion device is further configured to:

receive, from the primary power source, the AC electrical power at the third frequency;

convert the AC electrical power at the third frequency to AC electrical power at a fourth frequency; and

store the AC electrical power at the fourth frequency in the at least one energy storage device.

8. The power supply system of claim 4, wherein the power conversion device is further configured to:

receive, from the at least one generator, the AC electrical power at the first frequency;

convert the AC electrical power at the first frequency to AC electrical power at a fourth frequency; and

store the AC electrical power at the fourth frequency in the at least one energy storage device.

9. The power supply system of claim 1, wherein the at least one generator is a variable-frequency generator.

10. The power supply system of claim 1, wherein the second frequency is 60 Hz.

11. The power supply system of claim 1, wherein the second frequency is 50 Hz.

12. A method for providing uninterruptible power to a system load comprising:

monitoring a power level associated with a primary power source;

determining a power requirement associated with a system load;

converting electrical energy stored in an energy storage device to an AC electrical power at a first frequency associated with the system load, if the monitored power level is less than the power requirement;

activating a variable-frequency generator if the electrical energy stored in the energy storage device falls below a threshold level, the variable-frequency generator configured to generate AC electrical power at a second frequency; and

converting the AC electrical power at the second frequency to AC electrical power at the first frequency.

13. The method of claim 12, wherein the energy storage device includes a battery configured to store DC electrical power.

14. The method of claim 13, further including:

converting the AC electrical power at the second frequency to DC electrical power; and

storing the DC electrical power in the energy storage device.

15. The method of claim 13, further including:

receiving an AC electrical power at a fourth frequency associated with the primary power source;

converting the AC electrical power at the fourth frequency to a DC electrical power; and

storing the DC electrical power in the energy storage device.

16. The method of claim 12, where the energy storage device is configured to store AC electrical power at a third frequency.

17. The method of claim 16, further including:

converting the AC electrical power at the second frequency to AC electrical power at the third frequency; and

storing the AC electrical power at the third frequency in the energy storage device.

18. The method of claim 16, further including:

receiving an AC electrical power at a fourth frequency associated with the primary power source;

converting the AC electrical power at the fourth frequency to AC electrical power at a third frequency; and

storing the AC electrical power at the third frequency in the energy storage device.

19. A genset and an uninterruptible power supply configuration, comprised of:

at least one engine;

at least one generator;

at least one energy storage device;

at least one primary power source;

at least one load electrically coupled to the at least one generator, the at least one energy storage device, and at least one primary power source and configured to receive electrical power from the at least one generator, the at least one energy storage device, and at least one primary power source; and

a power electronics circuit configured to synchronize a frequency and control a direction of flow of electrical power between the at least one generator, the at least one energy storage device, and the at least one primary power source.

20. The configuration of claim 19, wherein the power electronics circuit is further configured to:

convert a variable-frequency AC electrical power to a fixed-frequency AC electrical power;

convert a DC electrical power to a fixed-frequency AC electrical power;

convert a fixed-frequency AC electrical power to a DC electrical power; and

convert a variable-frequency AC electrical power to a DC electrical power.

21. The configuration of claim 19, wherein the at least one generator is a variable-frequency generator.

22. An uninterruptible power supply electrically coupled to at least one generator, the uninterruptible power supply comprising:

at least one energy storage device configured to store an electrical power; and

a power conversion device electrically coupled to the at least one energy storage device and the at least one generator and configured to convert an AC electrical power output at a first frequency and an electrical power stored in the at least one energy storage device to an AC electrical power at a second frequency.