Method for operation of a power generation plant

• US 20050172630A1
• Filed: 01/04/2005
• Published: 08/11/2005
• Est. Priority Date: 07/04/2002
• Status: Active Grant

• Current Assignee: General Electric Technology GmbH (GE Vernova, Inc.)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: Althaus, Rolf, Koller, Martin, Wiederhold, Karl
• Granted Patent: US 7,464,551 B2
• Time in Patent Office: Days
• US Class Current: 60/648
• CPC Class Codes: F02C 6/16 for storing compressed air
• CPC Class Codes: H02J 15/006 in the form of pneumatic energy, e.g. compressed air energy storage [CAES] accumulators for supplying fluid under pressure F15B1/04
• CPC Class Codes: H02J 3/28 Arrangements for balancing of the load in a network by storage of energy
• CPC Class Codes: H02J 3/466 Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids

Abstract

A storage power station (S), for example an air storage plant, that includes a compressor unit (V), a turbine unit (T) and a storage volume (100) can be operated using a specific method of operation, which allows as fast a reaction as possible to changes in the load demands. Rapid changes in the load demands can be satisfied by controlling the power consumption of the compressor unit (V), which results in a variable net power output, with the power output from the turbine unit (T) remaining constant. The power of the compressor unit can be controlled approximately one order of magnitude more quickly than the power generation machine can be controlled. In the extreme, the compressor unit can simply be shut down, thus resulting in its drive power becoming available to an electricity grid within seconds. During this process, the turbine unit can continue to operate normally, and can slowly follow the power demand, thus reducing the load on the turbine. A storage power station can thus be ideally suitable for frequency support and for covering rapid load ramps in an electricity grid.

Claims

1. A method for operating a power generation plant in an electricity grid, the power generation plant including,

at least one storage volume for storing an energy storage fluid therein.

at least one power generation machine for operation with energy storage fluid, the power generation machine drivingly connected to a generator and capable of supplying electric power output via the generator during operation.

at least one power consuming machine for feeding energy storage fluid into the storage volume, the power consuming machine drivingly connected to a motor and consuming power during operation via the motor.

the power generation plant supplying a net power output (PNET) as the difference between the power output by the power generation machine and the power consumption (PJ of the motor, comprising:

operating the power generation plant in a first operating mode at a first grid power demand, the first operation mode including operating the power generation machine with a first power output and operating the power consuming machine with a first power consumption; and

upon a change of the power demand to a second power demand, matching the net power output of the power generation plant to the second power demand by changing the power consumption of the power consuming machine.

2. The method as recited in claim 1, further comprising:

maintaining the power supplied by the power generation machine constant.

3. The method as recited in claim 1, further comprising:

operating the power consuming machine to approximately compensate for load fluctuations in the grid, such that the power consumption of the power consuming machine is controlled to maintain the sum of the power consumption of the power consuming machine and the power demand from the grid to be approximately constant.

4. The method as recited in claim 3, wherein operating the power consuming machine includes regulating the constancy of the total power consumption to less than 5% of the maximum power output of the power generation machine.

5. The method as recited in claim 1, further comprising:

decreasing the power consumption of the power consuming machine when the power demand is increased to a second power demand; and

increasing the power output of the power generation machine, with the net power output being maintained approximately constant and equal to the second power demand.

6. The method as recited in claim 1, further comprising:

increasing the power consumption of the power consuming machine when the power demand is reduced to a second reduced power demand; and

reducing the power output of the power generation machine, with the net power output being maintained approximately constant and equal to the second reduced power demand.

7. The method as recited in claim 1, wherein, in the first operating mode, the mass flow of the energy storage fluid which is fed to the storage volume and the mass flow of the energy storage fluid which flows out of the storage volume are equal.

8. The method as recited in claim 1, wherein the power generation plant includes two or more power consuming machines which can be controlled independently of one another, further comprising:

upon a rise in the power demand, successively deloading and/or shutting down individual power consuming machines, and

upon a decrease in the power demand, successively uploading and/or starting individual power consuming machines.

9. The method as recited in claim 1, wherein the power generation plant includes two or more power generation machines which can be controlled independently of one another, further comprising:

upon a rise in the power demand, successively uploading and/or starting individual power generation machines; and

upon a decrease in the power demand, successively deloading and/or shutting down individual power generation machines.

10. The method as recited in claim 1, wherein the power generation plant includes a plurality of power generation machines and a plurality of power consumption machines, further comprising:

maintaining maximum power dynamic response capability by operating all the power consuming machines each at at least 80% of their maximum power consumption, and by maintaining the generators of all the power generation machines synchronized and connected to the grid, with the power generation machines each being operated at the minimum permissible power output.

11. The method as recited in claim 10, further comprising:

operating the power generation machines at less than 20% of their maximum power output.

12. The method as recited in claim 1, wherein the power demand is commanded by a grid operator utility.

13. The method as recited in claim 10, further comprising:

operating the power generation machines at less than 10% of their maximum power output.

14. The method as recited in claim 1, further comprising:

maintaining maximum power dynamic response capability by operating the power consuming machine at at least 80% of its maximum power consumption, and by maintaining the generator of the power generation machine synchronized and connected to the grid, with the power generation machine being operated at the minimum permissible power output.

15. The method as recited in claim 14, further comprising:

operating the power generation machine at less than 20% of its maximum power output.

16. The method as recited in claim 14, further comprising:

operating the power generation machine at less than 10% of its maximum power output.

17. The method as recited in claim 5, wherein decreasing occurs in a first step, and decreasing and increasing occurs in a second step.

18. The method as recited in claim 6, wherein increasing occurs in a first step, and increasing and decreasing occurs in a second step.