Methods and apparatus for ride-through operation of a complementary device to a transient power source

• US 7,358,620 B2
• Filed: 09/30/2004
• Issued: 04/15/2008
• Est. Priority Date: 09/30/2004
• Status: Expired due to Fees

• Current Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Inventors: Melfi, Michael J.
• Primary Examiner(s): Schuberg; Darren
• Assistant Examiner(s): Cuevas; Pedro J.
• Application Number:
  US10/955,210
• Publication Number:
  US 20060066104A1
• Time in Patent Office: 1,293 Days
• Field of Search: 290/1.A
• US Class Current: 290/1.00A
• CPC Class Codes: H02J 9/066 characterised by the use of dynamo-electric machines H02J9/08 takes precedence
• CPC Class Codes: H02K 7/025 for power storage
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids

Abstract

In accordance with certain exemplary embodiments, the present technique provides methods and apparatus for providing operating power to a complementary device to an induction device based uninterruptible power source (UPS) via a direct current (dc) bus. In one embodiment, the UPS includes a flywheel that stores kinetic energy during conventional operating conditions, e.g., external power is available. During such operating condition, the external power operates the induction device as an induction motor. However, when external power is lost, i.e., a transient operating condition, power conversion circuitry of the UPS provides ac power to the induction device such that the induction device operates above its synchronous speed and, as such, acts as an induction generator. However to improve the operating of the exemplary UPS, it includes second power conversion circuitry that converts both generated and received power to a power level that is desirable to complementary device cooperating with the induction device.

Claims

1. A power supplying apparatus, comprising:

a direct current (dc) bus configured to route a dc power;

a first power conversion circuitry that is electrically coupled to the dc bus and that is configured to convert the dc power to a first alternating current (ac) power at a variable frequency;

a second power conversion circuitry that is electrically coupled to the dc bus and that is configured to convert the dc power to a second ac power at a given frequency;

a third power conversion circuitry that is electrically coupled to the dc bus and that is configured to convert an external ac power to the dc power wherein the first ac power is transmitted via a first ac bus, the second ac power is transmitted via a second ac bus, the third ac power is transmitted via a third ac bus, and wherein the first ac bus, the second ac bus, and the third ac bus are separate from one another;

an electrical machine, comprising;

a kinetic energy storage device;

a stator having a rotor chamber and electrical conductors configured to receive the first ac power; and

a rotor disposed in the rotor chamber and mechanically coupled to the kinetic energy storage device, wherein the first power conversion circuitry is configured to provide the first ac power at the variable frequency to generate power from the electrical machine; and

a complementary device configured to receive the second ac power at the given frequency from the second power conversion circuitry, wherein the complementary device is configured to provide resources to complement operation of the electrical machine, and wherein the complementary device is mechanically coupled to the electrical machine.

2. The power supplying apparatus as recited in claim 1, wherein the kinetic energy storage device comprises a flywheel.

3. The power supplying apparatus as recited in claim 1, wherein the complementary device comprises a magnetic bearing device.

4. The power supplying apparatus as recited in claim 1, wherein the complementary device comprises a lubrication device.

5. The power supplying apparatus as recited in claim 1, wherein the complementary device comprises a cooling device.

6. The power supplying apparatus as recited in claim 1, comprising a sensor configured to determine a rotation rate of the rotor or the kinetic energy storage device, wherein the variable frequency is based on the rotation rate.

7. The power supplying apparatus as recited in claim 1, wherein the complementary device comprises an oil circulation system configured to circulate a pressurized cooling lubricant through a first bearing assembly configured to facilitate rotation of the rotor and through a second bearing assembly configured to facilitate rotation of the kinetic energy storage device.

8. The power supplying apparatus as recited in claim 1, wherein the complementary device comprises an air cooling device directly coupled to the electrical machine, comprising a fan configured to draw in external air and force the air into an internal region about the stator and rotor and expel the air from a vent located on the opposite end of the electrical machine, wherein the air is configured to remove heat from the electrical machine.

9. The power supplying apparatus as recited in claim 1, wherein the complementary device operates exclusively on power provided via the dc bus and the third power conversion circuitry.

10. A system for providing a transient power supply, comprising:

a direct current (dc) bus configured to route a dc power;

a first power conversion circuitry electrically coupled to the dc bus and configured to convert the dc power to a first alternating current (ac) power at a variable frequency;

a second power conversion circuitry that is electrically coupled to the dc bus and that is configured to convert the dc power to a second ac power at a given frequency;

a first ac bus that electrically couples the first power conversion circuitry and an induction device;

a second ac bus that electrically couples the second power conversion circuitry and a complementary device;

the induction device, comprising;

a kinetic energy storage device;

a stator having a rotor chamber and electrical conductors configured to receive the first ac power via the first ac bus; and

a rotor disposed in the rotor chamber and mechanically coupled to the kinetic energy storage device, wherein the first power conversion circuitry is configured to provide the first ac power at the selected frequency via the first ac bus to generate power from the induction device, and wherein the induction device is configured to generate a third ac power that is output during a transient power condition; and

the complementary device is configured to receive the second ac power exclusively from the dc bus via the second power conversion circuitry and the second ac bus, wherein the complementary device is configured to provide thermal and/or mechanical resources to complement operation of the induction device.

11. The system as recited in claim 10, wherein the kinetic energy storage device comprises a rotatable flywheel.

12. The system as recited in claim 10, wherein the complementary device comprises a magnetic bearing device.

13. The system as recited in claim 10, wherein the complementary device comprises a cooling device.

14. The system as recited in claim 10, wherein the complementary device comprises a lubrication device.

15. The system as recited in claim 10, comprising a third power conversion circuitry electrically coupled to the dc bus and that is configured to convert an external ac power from an external ac bus to the dc power, wherein the external ac bus is separate from the first ac bus and the second ac bus.

16. A system for providing a transient power supply, comprising:

a rotatable kinetic energy storing device;

a first power conversion circuitry configured to convert inputted power between a direct current (dc) power and a first alternating current (ac) power and to receive the first ac power from an external power source;

a dc bus electrically coupled to the first power conversion circuitry and configured to receive a dc power from the first power conversion circuitry;

a second power conversion circuitry that is electrically coupled to the dc bus and that is configured to convert between the dc power and a second alternating current (ac) power at a selectable frequency;

a third power conversion circuitry that is electrically coupled to the dc bus and that is configured to convert the dc power to a third ac power that is isolated from the external power source;

an electrical machine, comprising;

a stator having a rotor chamber and a plurality of electrical conductors configured to receive the second ac power from the second power conversion circuitry; and

a rotor disposed in the rotor chamber and mechanically coupled to the rotatable kinetic energy storage device, wherein the selectable frequency is based on the operating parameter of the electrical machine and facilitates power generation of a fourth ac power by the electrical machine; and

a complementary device mechanically coupled to the electrical machine, wherein the complementary device is configured to provide resources to facilitate operation of the electrical machine and to operate exclusively on the third ac power received from the third power conversion circuitry.

17. The system as recited in claim 16, wherein the kinetic energy storing device comprises a flywheel.

18. The system as recited in claim 16, wherein the complementary device comprises a cooling device, a magnetic device, a lubricant device or a monitoring device.

19. The system as recited in claim 16, comprising a sensor configured to determine a rotational rate of the kinetic energy storage device or the rotor.

20. The system as recited in claim 16, comprising a housing, wherein the kinetic energy storage device, the complementary device and the electric machine are disposed in the housing.

21. The system as recited in claim 16, wherein the electrical machine comprises an induction machine.

22. The system as recited in claim 16, wherein providing resources to facilitate operation of the electrical machine comprises providing mechanical resources to facilitate operation of the electrical machine.

23. The system as recited in claim 16, wherein providing resources to facilitate operation of the electrical machine comprises providing thermal resources to facilitate operation of the electrical machine.

24. A system for providing a transient power supply, comprising:

a first alternating current (ac) bus electrically coupled to a first power conversion circuitry and configured to route a first ac power;

a direct current (dc) bus electrically coupling the first power conversion circuitry, a second power conversion circuitry, and a third power conversion circuitry, wherein the dc bus is configured to route a dc power;

a second ac bus electrically coupling the second power conversion circuitry and an electrical machine;

a third ac bus electrically coupling a third power conversion circuitry and a complementary device, wherein the first ac bus, the second ac bus, and the third ac bus are separate from one another;

the first power conversion circuitry being configured to convert the first ac power to the dc power on the dc bus;

the second power conversion circuitry being configured to convert between the dc power and a second ac power at a second frequency that is variable;

an electrical machine, comprising;

a rotatable flywheel;

a stator having a rotor chamber and a plurality of stator windings configured to receive the second ac power via the second ac bus; and

a rotor disposed in the rotor chamber and mechanically coupled to the rotatable flywheel;

a sensor configured to sense an operating parameter of the electrical machine, wherein the second frequency is based on the operating parameter and facilitates the generation of a third ac power at the second frequency by the electric machine during operation; and

the third power conversion circuitry being configured to convert the dc power to a fourth ac power at a third frequency; and

the complementary device configured to receive the fourth ac power via the third ac bus, wherein the complementary device is configured to operate on the fourth ac power to provide resources to facilitate operation of the electrical machine.

25. The system as recited in claim 24, wherein the second frequency is based on the rotational rate of the rotatable flywheel or the rotor.

26. The system as recited in claim 24, comprising a housing, wherein at least two of the first, second and third frequencies are the same.

27. The system as recited in claim 24, wherein at least two of the first, second and third frequencies are different.

28. The system as recited in claim 24, wherein the complementary device comprises, a cooling device, a monitoring device, a lubrication device or a magnetic bearing device.

29. The system as recited in claim 24, wherein the rotor comprises a squirrel cage rotor.

30. The system as recited in claim 24, wherein the first ac bus is configured to receive the first ac power from an external power source.

31. The system as recited in claim 24, wherein during a transient power condition the third ac power is output to the second ac bus.

32. The system as recited in claim 24, wherein during a transient power condition the third ac power is output to a fourth ac bus that is electrically coupled to the second power conversion circuitry.

33. A method of providing operating power to a complementary device of an electrical machine, comprising:

converting a provided power to a first alternating current (ac) power at a selectable frequency;

providing the first ac power to electrical conductors disposed in the electrical machine at the selectable frequency to produce generated ac power via the electrical machine;

converting the generated ac power to a generated dc power; and

converting the generated dc power to a second ac power to operate the complementary device, wherein the complementary device operates exclusively on the second ac power, the complementary device is configured to provide resources to facilitate operation of the electrical machine, and the complementary device comprises a device mechanically coupled to the electrical machine.

34. The method as recited in claim 33, comprising routing the generated dc power and the provided dc power over a dc bus.

35. The method as recited in claim 33, comprising cooling the electrical machine via the complementary device.

36. The method as recited in claim 33, comprising circulating a lubricant with respect to the electrical machine via the complementary device.

37. The method as recited in claim 33, determining an operating parameter of the electrical machine and selecting the selectable frequency based on the operating parameter.

38. The method as recited in claim 33, comprising conditioning the generated power to match the frequency and voltage of an external alternating current power configured to provide operating power to a load during operation.

39. A system for providing a transient power supply, comprising:

means for converting a provided power to a first alternating current (ac) power at a selectable frequency;

means for generating a generated power from an electrical machine by converting stored kinetic energy into electrical energy in response to providing the first ac power at the selected frequency to the electrical machine;

means for routing the generated power to the complementary device; and

means for converting the generated power to a second ac power to operate the complementary device, wherein the complementary device operates exclusively from the generated power, and wherein the complementary device is mechanically coupled to the electrical machine and is configured to provide at least one of thermal or mechanical resources to facilitate operation of the electrical machine.