Power station and method for its operation

Patent metadata

Field	Value
Publication number	US-9605556-B2
Application number	US-54146009-A
Country	US
Kind code	B2
Filing date	Aug 14, 2009
Priority date	Feb 14, 2007
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A power station ( 10 ) is provided having a turbine shafting ( 11 ) including a gas turbine ( 12 ) and a generator ( 18 ) which is driven directly by the gas turbine ( 12 ), produces alternating current at an operating frequency and whose output is connected to an electrical grid ( 21 ) with a predetermined grid frequency. An electronic decoupling apparatus or a variable electronic gearbox ( 27 ) is arranged between the generator ( 18 ) and the electrical grid ( 21 ), and decouples the operating frequency from the grid frequency.

First claim

What is claimed is:

1. A power station having a turbine shafting comprising:
a gas turbine and a generator which is driven directly by the gas turbine, that produces alternating current at an operating frequency and whose output is connected to an electrical grid with a given grid frequency, wherein a variable electronic gearbox is arranged between the generator and the electrical grid to facilitate power from the generator being output to the electrical grid and to control a rotation speed of the gas turbine, wherein the variable electronic gearbox of the gas turbine is configured to impose the rotation speed on the gas turbine via a conversion ratio between a mechanical rotation speed of the gas turbine and the grid frequency via the generator to facilitate the output of power from the generator to the electrical grid and to thereby control the rotation speed of the gas turbine.

2. The power station as claimed in claim 1 , wherein the conversion ratio is controllable and is a frequency ratio between the rotation speed of the gas turbine and the grid frequency.

3. The power station as claimed in claim 1 , wherein the conversion ratio is not equal to unity.

4. The power station as claimed in claim 1 , wherein the conversion ratio is 60 Hz to 50 Hz or the conversion ratio is 50 Hz to 60 Hz.

5. The power station as claimed in claim 1 , wherein the conversion ratio is controllable around a design value of 60 Hz to 50 Hz or around a design value of 50 Hz to 60 Hz.

6. The power station as claimed in claim 1 , wherein the variable electronic gearbox is a matrix converter.

7. The power station as claimed in claim 6 , wherein the matrix converter comprises a plurality of controllable bidirectional switches which are arranged in an m×n matrix and, controlled by a controller, connect m inputs selectively to n outputs, where m is greater than n, and where a first device is provided for determining the polarity of the currents in the inputs, and a second device is provided for determining the polarity of the voltages between the inputs, and where the first and second devices are connected to the controller by signal lines.

8. The power station as claimed in claim 1 , wherein the gas turbine is a gas turbine with sequential combustion.

9. A method for operation of a power station having a turbine shafting, comprising:
a gas turbine and a generator which is driven directly by the gas turbine that produces alternating current at an operating frequency and whose output is connected to an electrical grid with a given grid frequency wherein a variable electronic gearbox is arranged between the generator and the electrical grid to facilitate power from the generator being output to the electrical grid and to control a rotation speed of the gas turbine, wherein the variable electronic gearbox of the gas turbine is configured to impose a rotation speed on the gas turbine via a conversion ratio between a mechanical rotation speed of the gas turbine and the grid frequency via the generator, the method comprising:
controlling a mechanical or aerodynamic rotation speed of the gas turbine via use of the conversion ratio between the mechanical rotation speed and the grid frequency to impose the rotation speed on the gas turbine via the variable electronic gearbox to facilitate the output of power from the generator to the electrical grid.

10. The method as claimed in claim 9 , wherein the mechanical or aerodynamic rotation speed of the gas turbine is controlled at a constant value.

11. The method as claimed in claim 9 , wherein the mechanical or aerodynamic rotation speed of the gas turbine is controlled as a function of at least one parameter of the power station and wherein the conversion ratio is a frequency ratio between the rotation speed of the gas turbine and the grid frequency.

12. The method as claimed in claim 11 , wherein the gas turbine has a compressor for compression of combustion air, and the method comprising at least one of:
(i) measuring an outlet pressure of the compressor and wherein the controlling of the mechanical or aerodynamic rotation speed of the gas turbine is also controlled as a function of the compressor outlet pressure, and
(ii) measuring an outlet temperature of the compressor and wherein the controlling of the mechanical or aerodynamic rotation speed of the gas turbine is also controlled as a function of the compressor outlet temperature.

13. The method as claimed in claim 11 , wherein an intended power is predetermined for operation of the gas turbine and the mechanical or aerodynamic rotation speed of the gas turbine is controlled as a function of the intended power.

14. The method as claimed in claim 11 , comprising at least one of:
measuring the grid frequency of the electrical grid and measuring the second operating frequency; and
wherein the controlling of the mechanical or aerodynamic rotation speed of the gas turbine is also controlled as a function of at least one of the measured grid frequency and the measured second operating frequency.

15. A method for operation of a power station, having a turbine shafting comprising a gas turbine and a generator which is driven directly by the gas turbine, that produces alternating current at an operating frequency and whose output is connected to an electrical grid with a given grid frequency, wherein a variable electronic gearbox is arranged between the generator and the electrical grid the variable electronic gearbox of the gas turbine imposes a rotation speed with a conversion ratio between a mechanical rotation speed of the gas turbine and the grid frequency via the generator, the method comprising:
controlling a mechanical or aerodynamic rotation speed of the gas turbine via the conversion ratio between the mechanical rotation speed and the grid frequency, wherein the mechanical or aerodynamic rotation speed of the gas turbine is controlled as a function of at least one parameter of the power station; and
wherein the gas turbine has a compressor for compression of combustion air, cooling air is taken from the compressor in order to cool components of the gas turbine and the mechanical or aerodynamic rotation speed of the gas turbine is also controlled as a function of at least one cooling air feed condition comprising at least one of (i) a pressure of the cooling air, a temperature of the cooling air, and an amount of the cooling air.

16. The method as claimed in claim 15 , wherein the mechanical or aerodynamic rotation speed of the gas turbine is controlled as a function of permissible component temperatures of selected components of the gas turbine, or as a function of permissible emissions.

17. The method as claimed in claim 15 , wherein the mechanical rotation speed is controlled in proportion to at least one of: (i) the square root of the compressor inlet temperature and (ii) the compressor inlet pressure in order to keep the aerodynamic rotation speed of the gas turbine at a constant value in the permissible mechanical rotation speed range, and the mechanical rotation speed is controlled at a constant value as soon as mechanical or other limit values are reached.

18. The method as claimed in claim 9 , wherein, when at least one of (i) the rotation speed of the shaft section and (ii) rotation speed of the shaft section in combination with the variable electronic gearbox falls within a blocking range, a target rotation speed or the conversion ratio of the variable electronic gearbox is corrected to a value outside the respective blocking range.

19. A power station having a turbine

Assignees

• Hoffmann Jürgen
• Meindl Thomas
• Gen Electric

Inventors

• Hoffmann Jürgen
• Meindl Thomas

Classifications

• F01D15/10 Primary

  Adaptations for driving, or combinations with, electric generators · CPC title

• F02C9/28

  Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed (F02C9/30 - F02C9/38, F02C9/44 take precedence) · CPC title

• F05D2270/024

  to keep rotational speed constant · CPC title

• F02C9/38

  characterised by throttling and returning of fuel to sump · CPC title

• F05D2270/05

  to affect the output of the engine · CPC title