Energy Systems, Energy Devices, Energy Utilization Methods, and Energy Transfer Methods

• US 20090322084A1
• Filed: 06/30/2008
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Enel X North America, Inc. (ENEL SPA)
• Original Assignee: Demand Energy Networks, Inc. (ENEL SPA)
• Inventors: Hamilton, Scott Robert
• Granted Patent: US 8,097,967 B2
• Time in Patent Office: Days
• US Class Current: 290/44
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 2300/40 wherein a plurality of decentralised, dispersed or local energy generation technologies are operated simultaneously
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator
• CPC Class Codes: H02P 9/46 Control of asynchronous generator by variation of capacitor
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

Energy systems, energy devices, energy utilization methods, and energy transfer methods are described. In one arrangement, energy utilization methods include providing first energy from a power grid to an induction generator at a first moment in time; using the induction generator and the first energy from the power grid, charging an energy storage device; using second energy from the energy storage device, powering a motor causing the induction generator to generate third energy during a second moment in time; and providing the third energy to the power grid. Other arrangements are described.

Claims

1. An energy system comprising:

a shaft;

a stator positioned adjacent to the shaft;

a motor configured to use energy stored by an energy storage device to rotate the shaft; and

wherein the stator is configured to supply power to an alternating current power grid at a moment in time when the stator is electrically connected to the power grid and the motor is turning the shaft.

2. The system of claim 1 further comprising an energy conversion device configured to convert rotational energy of the shaft into a form suitable for storage by the energy storage device at a moment in time when the motor is not rotating the shaft.

3. The system of claim 1 further comprising an energy conversion device configured to convert naturally occurring energy into a form suitable for storage by the energy storage device.

4. The system of claim 1 further comprising an energy conversion device configured to convert energy derived from the power grid into a form suitable for storage by the energy storage device.

5. The system of claim 1 wherein the energy storage device comprises a battery and further comprising a battery charger configured to charge the battery.

6. The system of claim 1 further comprising control circuitry configured to selectively cause the motor to rotate the shaft.

7. The system of claim 6 wherein the control circuitry comprises a first portion located near the motor and a second portion remotely located from the motor and the first portion is configured to communicate with the second portion via a communications network.

8. The system of claim 6 wherein the motor comprises a first motor, the control circuitry comprises a third portion located near a second motor, and the second portion is configured to communicate with the third portion via the communications network and to selectively cause the second motor to rotate.

9. The system of claim 6 wherein the control circuitry is configured to detect that a frequency of the power grid is below a threshold and in response to the determining cause the motor to rotate the shaft.

10. The system of claim 6 wherein the control circuitry is configured to detect that a frequency of the power grid is above a threshold and in response to the determining prevent the motor from rotating the shaft.

11. The system of claim 6 wherein the control circuitry is configured to determine an amount of energy stored by the energy storage device and based on the amount of energy cause the motor to rotate the shaft.

12. The system of claim 6 wherein the control circuitry is configured to selectively electrically connect the stator to the power grid to enable the stator to supply power to the power grid.

13. An energy device comprising:

an induction generator comprising a shaft and a stator and configured to rotate the shaft at a first moment in time when the stator is electrically connected to an alternating current power grid;

a motor configured to use energy stored by an energy storage device to rotate the shaft;

an energy conversion device configured to convert rotational energy of the shaft to potential energy to be stored by the energy storage device; and

wherein the induction generator is configured to provide alternating current power to the power grid via the stator at a second moment in time when the motor is rotating the shaft and the stator is electrically connected to the power grid.

14. The device of claim 13 wherein the shaft comprises a first shaft, the motor comprises a second shaft coupled to the first shaft, and the motor is configured to rotate the second shaft.

15. The device of claim 13 wherein:

the energy storage device comprises a battery; and

the energy conversion device is configured to generate direct current power when the shaft is rotating and to use the direct current power to charge the battery.

16. The device of claim 15 wherein the energy conversion device is configured to supply a first amount of energy to the battery in a first amount of time and the motor is configured to consume the first amount of energy in a second amount of time, the first amount of time being less than the second amount of time.

17. The device of claim 13 wherein the energy conversion device is configured to convert the rotational energy of the shaft to potential energy stored by the energy storage device at a moment in time when the stator is electrically connected to the power grid.

18. The device of claim 13 further comprising control circuitry configured to electrically connect the stator to the power grid and to cause the motor to rotate thereby enabling the induction generator to provide the alternating current power to the power grid.

19. The device of claim 18 wherein the control circuitry is configured to prevent the energy conversion device from converting the rotational energy to the potential energy during times when the motor is rotating and consuming power derived from the energy storage device.

20. The device of claim 13 wherein the energy storage device stores compressed gas.

21. The device of claim 13 wherein:

the energy storage device comprises a battery;

the motor is an alternating current induction motor; and

further comprising an inverter configured to convert the energy stored by the battery into first alternating current power having a frequency higher than a frequency of second alternating current power provided by the power grid and to provide the first alternating current power to the alternating current induction motor.

22. The device of claim 13 wherein:

the motor is configured to rotate the shaft at a rotational speed greater than a synchronous speed of the induction generator;

the stator comprises two poles; and

the synchronous speed in revolutions per minute is equal to a frequency of alternating current power of the power grid times sixty.

23. An energy utilization method comprising:

receiving a request to provide alternating current power to a power grid;

in response to the receiving of the request, enabling a motor to rotate a shaft of an induction generator, the motor consuming energy stored by an energy storage device to rotate the shaft; and

subsequent to the enabling, providing alternating current power generated by the induction generator to the power grid.

24. The method of claim 23 wherein the induction generator is a three-phase alternating current induction generator.

25. The method of claim 23 wherein the induction generator is a single-phase alternating current induction generator.

26. The method of claim 23 wherein an excitation voltage of the induction generator is supplied by the power grid.

27. An energy providing method comprising:

using a motor, rotating a shaft of an induction generator at a rotational speed greater than a synchronous speed of the induction generator;

while the shaft is rotating, generating alternating current power using the induction generator; and

transferring the generated alternating current power to a power grid.

28. The method of claim 27 wherein the using the motor to rotate the shaft comprises consuming energy stored by an energy storage device.

29. The method of claim 28 wherein the motor is a direct current electric motor and further comprising using a pulse width modulator to supply a consistent amount of power to the direct current electric motor from the energy storage device while the direct current electric motor is rotating the shaft.

30. The method of claim 27 wherein the motor is an alternating current electric motor and further comprising using a variable frequency drive to supply an alternating current having a consistent frequency to the alternating current electric motor while the alternating current electric motor is rotating the shaft.

31. The method of claim 27 wherein the motor comprises a pneumatic motor.

32. The method of claim 27 wherein the motor comprises a hydraulic motor.

33. The method of claim 27 wherein:

the shaft comprises a first shaft;

the motor comprises a clutch and a second shaft coupled to the first shaft; and

the method further comprises;

engaging the clutch when the motor is enabled;

disengaging the clutch when the motor is disabled; and

wherein a rotational friction associated with rotating the second shaft is less when the clutch is disengaged than when the clutch is engaged.

34. An energy transfer method comprising:

rotating a shaft of an induction generator at a rotational speed;

first transferring first electrical energy at a first rate to an alternating current power grid via a stator of the induction generator while the power grid is providing the stator with a first alternating excitation voltage having a first frequency, the first electrical energy resulting from the rotating of the shaft at the rotational speed; and

subsequent to the first transferring, second transferring second electrical energy at a second rate to the power grid via the stator while the power grid is providing the stator with a second alternating excitation voltage having a second frequency different than the first frequency, the second rate being different than the first rate and the second electrical energy resulting from the rotating of the shaft at the rotational speed.

35. The method of claim 34 wherein the first rate is greater than the second rate and the first frequency is less than the second frequency.

36. The method of claim 34 wherein the first rate is less than the second rate and the first frequency is greater than the second frequency.

37. The method of claim 34 wherein the first electrical energy transferred to the power grid comprises an alternating current.

38. An energy utilization method comprising:

providing first energy from a power grid to an induction generator at a first moment in time;

using the induction generator and the first energy from the power grid, charging an energy storage device;

using second energy from the energy storage device, powering a motor causing the induction generator to generate third energy during a second moment in time; and

providing the third energy to the power grid.

39. The method of claim 38 wherein the powering of the motor comprises powering the motor responsive to an electrical characteristic of the power grid.

40. The method of claim 38 wherein the charging comprises charging during a period of time when energy from the power grid is sold for a first price and the powering of the motor comprises powering the motor during a period of time when energy from the power grid is sold for a second price, the second price being higher than the first price.