Transient energy systems and methods for use of the same

• US 7,642,664 B1
• Filed: 11/29/2006
• Issued: 01/05/2010
• Est. Priority Date: 11/29/2006
• Status: Active Grant

• Current Assignee: P10 Industries, Inc.
• Original Assignee: Active Power Incorporated
• Inventors: Andrews, James A, Hudson, Robert S.
• Primary Examiner(s): Ponomarenko; Nicholas
• Assistant Examiner(s): Mohandesi; Iraj A
• Application Number:
  US11/606,849
• Time in Patent Office: 1,133 Days
• Field of Search: 290/1.A, 290/1.R, 290/40.C, 290/40.B, 290/52
• US Class Current: 290/1.00A
• CPC Class Codes: H02J 3/30 using dynamo-electric machines coupled to flywheels
• CPC Class Codes: H02P 9/46 Control of asynchronous generator by variation of capacitor
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids

Abstract

This disclosure relates to transient energy systems for supplying power to a load substantially instantaneously on demand. Transient energy systems may include a flywheel coupled the rotor of an induction motor generator. One embodiment of the disclosure refers to systems and methods for reducing loads on a bearing in a transient energy system. In another embodiment, the disclosure refers to an induction motor generator that is optimized for high power transient power generation, yet low power motor operation. Yet another embodiment of the disclosure refers to using a flywheel as a drag pump to cool components of a transient energy system. In yet another embodiment, a slip control scheme is discussed for regulating a DC bus. In yet a further embodiment of the disclosure a method is provided for reducing unnecessary turbine starts by making turbine start a function of the rotational velocity of a flywheel.

Claims

1. An uninterruptible backup power supply system that provides power to a critical load, the system comprising:

a flywheel energy storage system comprising a flywheel which rotates about an axis;

a compressed gas system comprising a source of compressed gas, a turbine, and a generator; and

control circuitry operative to;

monitor the rotational speed of the flywheel; and

when the monitored rotational speed slows down to a predetermined rotational speed, release gas from the source of compressed gas to drive the turbine, wherein the flywheel system is operative to supply backup power to the critical load in the event of a disruption in the supply of power from a primary power source to the critical load.

2. The system of claim 1, wherein the compressed gas system is operative to supply backup power to the critical load when the turbine is driving the generator.

3. The system of claim 1, wherein the flywheel speed decreases when the flywheel energy storage system provides backup power to the critical load.

4. The system of claim 1, the control circuitry operative to:

allow the flywheel energy storage system to temporarily provide power to the critical load without triggering a turbine start event.

5. The system of claim 1, wherein, while the compressed gas system provides backup power to the critical load, and in the event of an increased step change in load demand, the flywheel system is operative to provide backup power to the critical load at least until the compressed gas system compensates for the step change in load demand, and wherein the flywheel rotational speed decreases to a lower intermediate rotational speed as a result of the step change in load demand.

6. The system of claim 1, wherein, while the compressed gas system provides backup power to the critical load, and in the event of an decreased step change in load demand, the flywheel system is operative to absorb power from the compressed gas system, and wherein the flywheel rotational speed increases to a higher intermediate rotational speed as a result of the step change in load demand.

7. The system of claim 1, wherein the flywheel is operative to maintain an effective energy level to compensate for increases and decreases in step changes in load demand.

8. A method for determining turbine startup in an uninterruptible backup power supply system comprising a flywheel energy storage system and a compressed gas system, the method comprising:

monitoring the flywheel speed of the flywheel energy storage system; and

when the monitored flywheel speed slows down to a predetermined speed, initiating turbine startup of a turbine of the compressed gas system, wherein monitoring the flywheel speed comprises monitoring the flywheel speed while the flywheel energy storage system is providing power from a primary power source to the critical load.

9. The method of claim 8, wherein the flywheel speed decreases when the flywheel energy storage system provides backup power to the critical load.

10. The method of claim 8, wherein initiating turbine startup comprises:

releasing gas from a source of compressed gas;

providing the released gas to the turbine; and

driving the turbine with the released gas.

11. The method of claim 8, further comprising providing backup power from the compressed gas system to the critical load prior to fully depleting energy storage of the flywheel energy storage system.

12. The method of claim 8, further comprising:

allowing the flywheel energy storage system to temporarily provide power to the critical load without triggering a turbine start event.

13. A method for compensating for step changes in a load demand in an uninterruptible backup power supply system comprising a flywheel energy storage system and a compressed gas system, the method comprising:

using the compressed gas system to provide backup power to a load;

monitoring step changes in the load demand, the step changes comprising sudden step changes;

using the flywheel energy system to assist the compressed gas system in compensating for step changes in the load by supplying power to the load in the event of a sudden increase in load demand and absorbing power produced by the compressed gas system in the event of a sudden decrease in load demand.

14. The method of claim 13, further comprising:

rotating a flywheel of the flywheel energy system at an intermediate speed while the compressed gas system provides backup power to the load.

15. The method of claim 14, wherein the rotational speed decreases to a lower intermediate speed when power is temporarily provided by the flywheel energy system to supplement power provide by the compressed gas system.

16. The method of claim 14, wherein the rotational speed increases to a higher intermediate speed when excess power provided by the compressed gas system is absorbed by the flywheel energy system.

17. The method of claim 13, further comprising:

maintaining a rotational speed of a flywheel of the flywheel energy generation system at a speed effective for compensating for increases and decreases in load demand.