HYBRID ELECTRIC GENERATING POWER PLANT THAT USES A COMBINATION OF REAL-TIME GENERATION FACILITIES AND ENERGY STORAGE SYSTEM

• US 20120323396A1
• Filed: 06/19/2012
• Published: 12/20/2012
• Est. Priority Date: 06/20/2011
• Status: Active Grant

• Current Assignee: Fluence Energy LLC (AES Corporation)
• Original Assignee: AES Corporation
• Inventors: SHELTON, John Christopher, GEINZER, Jay Craig, GALURA, Brett Lance, MEERSMAN, Steven Christianne Gerard
• Granted Patent: US 9,559,520 B2
• Time in Patent Office: Days
• US Class Current: 700/297
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• 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 3/381 Dispersed generators
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: H02M 7/68 by static converters
• 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

Abstract

Approaches for controlling power supplied to an electric grid are disclosed. In embodiments, methods and systems control power supplied to an electric grid using an energy storage device. In an embodiment, a method receives an indication of power to be supplied to the electric grid, generates power from a power generator and adjusts, using the generated power, an energy level of the energy storage device to control power supplied to the grid in accordance with the received indication. In another embodiment, a system comprises a grid indication receiver for receiving an indication of power to be supplied to the electric grid; a power generator connected to the grid; an energy storage device coupled to the power generator; and a controller for adjusting, using the generated power from the generator, an energy level of the energy storage device to control power supplied to the grid in accordance with the received indication.

Claims

1. A method of controlling power supplied to an electric grid using an energy storage device to store energy, the method comprising:

receiving an indication of power to be supplied to the electric grid;

generating power from at least one power generator; and

adjusting, using the generated power from the power generator, an energy level of the energy storage device to control the power supplied to the electric grid in accordance with the received indication.

2. The method of claim 1, further comprising:

collocating the at least one power generator and the energy storage device together at a power generation site; and

coupling, via a station transformer at the power generation site, an output of the at least one power generator and an output of the energy storage device to the electric grid.

3. The method of claim 1, wherein responsive to receiving the one or more parameters indicating one or more operating set points for the combination of the at least one power generator and the energy storage device, determining, by a controller, the one or more other operating set points for each of the energy storage device and the at least one power generator such that the combination of the at least one power generator and the energy storage device satisfies the one or more operating set points indicated by the received one or more parameters.

4. The method of claim 1, further comprising:

adjusting the generated power from the at least one power generator simultaneously with the adjustment of the energy level of the energy storage device to meet the power to be supplied to the electric grid.

5. The method of claim 4, wherein the adjusting of the generated power from the at least one power generator simultaneously with the adjustment of the energy of the energy storage device includes one of:

(1) discharging the energy storage device and increasing the power supplied from the at least one power generator;

(2) discharging the energy storage device and decreasing the power supplied from the at least one power generator;

(3) charging the energy storage device and decreasing the power supplied from the at least one power generator;

or

(4) charging the energy storage device and increasing the power supplied from the at least one power generator.

6. The method of claim 5, wherein:

the discharging of the energy storage device and the increasing of the power supplied from the at least one power generator includes discharging stored power during initial ramp-up in power generation by the at least one power generator;

the charging of the energy storage device and decreasing of the power supplied from the at least one power generator includes storing power for later transmission on the electric grid during ramp-down in the power generation by the at least one power generator.

7. The method of claim 1, wherein the energy storage device includes a converter for converting direct current (DC) to alternating current (AC) and AC to DC.

8. The method of claim 1, wherein the receiving of the indication includes at least one of:

(1) receiving a signal that indicates a present power supply level to be supplied to the electric grid;

(2) receiving a signal indicating a grid frequency for determining a present adjustment to the power to be supplied to the electric grid;

or

(3) receiving one or more operating parameters indicating one or more operating set points for operation of a combination of the at least one power generator and the energy storage device.

9. The method of claim 8, further comprising:

responsive to receiving the signal indicating the grid frequency, determining a present adjustment to the power to be supplied to the electric grid; and

determining power contribution from the at least one power generator and power contribution from the energy storage device to satisfy the determined present adjustment.

10. The method of claim 8, further comprising responsive to receiving the signal that indicates the present power supply level to be supplied to the electric grid, determining power contribution from the at least one power generator and power contribution from the energy storage device to satisfy the indicated present power supply level.

11. The method of claim 8, wherein the reception of the signal indicating the grid frequency includes detecting instantaneous grid frequency.

12. The method of claim 1, wherein:

the received indication is a sequence of indications that indicate the power to be supplied to the electric grid during a period of time; and

the energy storage device and the at least one power generator have different power transient responses.

13. The method of claim 12, further comprising:

regulating the power supplied to the electric grid using either the energy storage device or the at least one power generator that has a faster power transient response.

14. The method of claim 12, further comprising:

determining a first component associated with power supply fluctuations below a threshold frequency and a second component associated with the power fluctuations at or above the threshold frequency;

adjusting the energy level of the energy storage device in accordance with the first component; and

adjusting generation of power from the at least one power generator in accordance with the second component.

15. The method of claim 1, further comprising:

storing energy in the energy storage device;

(1) at a first level that is below capacity during periods in which power demands on the electric grid are expected to decrease; and

(2) at a second level, higher than the first level, during periods in which the power demands on the electric grid are expected to increase.

16. The method of claim 1, further comprising:

adjusting the storage of energy by the power storage device according to an optimum discharge and storage profile or a predetermined power discharge and storage profile of the power storage device; and

adjusting, based on the optimum or predetermined power discharge and storage profile, power generation from the at least one power generator to satisfy the received indication.

17. The method of claim 16, wherein the optimum or the predetermined power discharge and storage profile of the energy storage device and an optimum or a predetermined ramp profile of the at least one power generator are based on at least two factors selected from the group consisting of:

(1) wear and tear on respective equipment;

(2) a maximum rate of change of the at least one power generator;

(3) an optimum rate of change of the at least one power generator;

(4) a fuel consumption rate profile of the at least one power generator;

(5) a state of charge (SOC) of the energy storage device;

(6) a durability of the respective equipment,

(7) costs of initial acquisition and depreciation of the at least one power generator and the energy storage device; and

(8) transmission losses of the power distributed by the electric grid.

18. The method of claim 1, further comprising:

adjusting the power generation from the at least one power generator according to an optimum ramp profile or a predetermined ramp profile of the at least one power generator; and

adjusting, based on the optimum or the predetermined ramp profile, the energy level of the energy storage device to satisfy the received indication.

19. An apparatus for controlling power supplied to an electric grid using at least one power generator and an energy storage device coupled to the electric grid, the apparatus comprising:

a grid indication receiver configured to receive an indication of power to be supplied to the electric grid; and

a controller configured to adjust, using the generated power from the power generator, an energy level of the energy storage device to control the power supplied to the electric grid in accordance with the indication received by the grid indication receiver.

20. The apparatus of claim 19, wherein the grid indication receiver is further configured to receive the indication which includes at least one of:

(1) a signal that indicates a present power supply level to be supplied to the electric grid;

(2) a signal indicating a grid frequency for determining a present adjustment to the power to be supplied to the electric grid;

or

(3) one or more operating parameters indicating one or more operating set points for operation of a combination of the at least one power generator and the energy storage device.

21. The apparatus of claim 19, wherein in response to receiving the one or more parameters indicating one or more operating set points for the combination of the at least one power generator and the energy storage device, the controller is configured to determine the one or more other operating set points for each of the energy storage device and the at least one power generator such that the combination of the at least one power generator and the energy storage device satisfies the one or more operating set points indicated by the received one or more parameters.

22. The apparatus of claim 19, wherein the controller is adjusts the generated power from the at least one power generator simultaneously with the adjustment of the energy level of the energy storage device to meet the power to be supplied to the electric grid.

23. The apparatus of claim 22, wherein the controller is further configured to control one of:

(1) discharging the energy storage device and increasing the power supplied from the at least one power generator;

(2) discharging the energy storage device and decreasing the power supplied from the at least one power generator;

(3) charging the energy storage device and decreasing the power supplied from the at least one power generator;

or

(4) charging the energy storage device and increasing the power supplied from the at least one power generator based on the received indication from the grid indication receiver.

24. The apparatus of claim 19, wherein:

the grid indication receiver is further configured to receive a sequence of indications indicating the power to be supplied to the electric grid during a period of time; and

the energy storage device and the at least one power generator have different power transient responses such that one of the energy storage device or the at least one power generator that has a faster power transient response regulates the power supplied to the electric grid.

25. The apparatus of claim 19, further comprising:

a filtering unit configured to determine a first component associated with power supply fluctuations below a threshold frequency and a second component associated with the power fluctuations at or above the threshold frequency, wherein,

the controller is further configured to adjust the energy level of the energy storage device in accordance with the first component and adjusts the generation of power from the at least one power generator in accordance with the second component.

26. The apparatus of claim 19, wherein:

the at least one power generator includes at least one of;

(1) a hydro-electric power generator;

(2) a fossil-fueled power generator;

(3) a nuclear power generator;

(4) a wind harnessing power generator;

(5) a tidal power generator;

(5) a geothermal power generator;

or

(6) a solar power generator; and

the energy storage device includes at least one of;

(1) a battery;

(2) a capacitor;

(3) an inertial power storage system;

(4) a pneumatic system;

or

(5) a suspended mass system.

27. The apparatus of claim 19, wherein the energy storage device includes a converter for converting direct current (DC) to alternating current (AC) and AC to DC.

28. The apparatus of claim 19, wherein the controller is further configured to control the energy storage device to store energy:

(1) at a first level that is below capacity during periods in which power demands on the electric grid are expected to decrease; and

(2) at a second level that is higher than the first level, during periods in which the power demands on the electric grid are expected to increase.

29. The apparatus of claim 19, wherein the controller is further configured to adjust the energy level of the power storage device according to an optimum power discharge and storage profile or a predetermined power discharge and storage profile of the power storage device and adjusts, based on the optimum or predetermined power discharge and storage profile, power generation from the at least one power generator to satisfy the received indication.

30. The apparatus of claim 19, wherein the controller is further configured to adjust power generation from the at least one power generator according to an optimum ramp profile or a predetermined ramp profile of the at least one power generator and adjusts, based on the optimum ramp profile or the predetermined ramp profile, the storage of energy of the energy storage device to satisfy the received indication.

31. A system for controlling power supplied to an electric grid, the system comprising:

a grid indication receiver configured to receive an indication of power to be supplied to the electric grid;

at least one power generator configured to generate power, the at least one power generator being connected to the electric grid;

an energy storage device configured to store energy, the energy storage device being coupled to the at least one power generator and the electric grid;

a controller configured to adjust, using the generated power from the power generator, an energy level of the energy storage device to control the power supplied to the electric grid in accordance with the indication received by the grid indication receiver.

32. A non-transitory computer readable storage medium having instructions stored thereon that, in response to execution by a computing device, cause the computing device to perform operations for controlling power supplied to an electric grid using an energy storage device to store energy, the operations comprising:

receiving an indication of power to be supplied to the electric grid;

generating power from at least one power generator; and

adjusting, using the generated power from the power generator, an energy level of the energy storage device to control the power supplied to the electric grid in accordance with the received indication.