Power Management During Grid Faults

• US 20110025059A1
• Filed: 06/30/2010
• Published: 02/03/2011
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: Vestas Wind Systems A/S
• Original Assignee: Vestas Wind Systems A/S
• Inventors: Andersen, Thomas Lundgren, Hjort, Thomas, Helle, Lars
• Granted Patent: US 8,742,609 B2
• Time in Patent Office: Days
• US Class Current: 290/44
• CPC Class Codes: F03D 15/10 using gearing not limited to rotary motion, e.g. with oscillating or reciprocating members
• CPC Class Codes: F03D 7/0224 Adjusting blade pitch
• CPC Class Codes: F03D 7/0284 in relation to the state of the electric grid
• CPC Class Codes: F03D 80/60 Cooling or heating of wind motors
• CPC Class Codes: F03D 9/10 Combinations of wind motors with apparatus storing energy
• CPC Class Codes: F03D 9/11 storing electrical energy
• CPC Class Codes: F03D 9/255 connected to electrical distribution networks; Arrangements therefor
• CPC Class Codes: F05B 2270/107 to cope with emergencies
• CPC Class Codes: H02P 9/00 Arrangements for controlling electric generators for the purpose of obtaining a desired output Ward-Leonard arrangements H02P7/34; vector control H02P21/00; feeding a network by two or more generators H02J; for charging batteries H02J7/14
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

A method for operating a wind turbine facility during for example a grid fault, the wind turbine facility comprising a power dissipation/storage being adapted to dissipate or store electrical energy exceeding an amount to be delivered to an associated power supply grid during the grid fault. The method includes operating the wind turbine facility in accordance with an allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage of the wind turbine facility by ensuring that a total amount of electrical energy generated by the wind turbine facility does not exceed a sum of the allowed amount and the amount to be delivered to the power supply grid.

Claims

1. A wind turbine facility adapted to deliver electrical energy to an associated power supply grid, the wind turbine facility comprising:

generator means for converting mechanical energy to electrical energy, the generator means being mechanically coupled to a set of rotor blades optionally via a gearing arrangement;

an electric power converter electrically coupled to the generator means and the associated power supply grid optionally via a grid transformer;

power dissipation/storage means being adapted to dissipate or store an amount of electrical energy from the generator means; and

control means for determining an allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage means.

2. The wind turbine facility according to claim 1, wherein the control means is adapted to determine the allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage means on a regular basis or in response to specific event, such as in periods following a grid fault.

3. The wind turbine facility according to claim 1, wherein the control means is adapted to operate the wind turbine facility in such a manner that a total amount of electrical energy generated by the wind turbine facility, in the event of a grid fault, does not exceed a sum of the allowed amount and an amount to be delivered to the power supply grid.

4. The wind turbine facility according to claim 3, wherein the control means is adapted to control the total amount of electrical energy generated by the wind turbine facility by activating a pitching system of the wind turbine facility

5. The wind turbine facility according to claim 1, further comprising means for determining a temperature of a power dissipation element of the power dissipation/storage means.

6. The wind turbine facility according the claim 5, wherein the control means is adapted to determine the allowed amount of electrical energy that can be dissipated in the power dissipation element on the basis of the determined temperature.

7. The wind turbine facility according to claim 1, further comprising means for determining a voltage across a power storage element of the power dissipation/storage means.

8. The wind turbine facility according the claim 7, wherein the control means is adapted to determine the allowed amount of electrical energy that can be stored in the power storage element on the basis of the determined voltage.

9. The wind turbine facility according to claim 1, wherein the power dissipation/storage means comprises a plurality of parallel coupled power dissipation elements and/or power storing elements.

10. The wind turbine facility according to claim 1, wherein the power dissipation/storage means comprises a plurality of parallel coupled power dissipation/storage elements, each power dissipation/storage element comprising power dissipation element and a power storing element.

11. The wind turbine facility according to claim 1, wherein at least part of the power dissipation/storage means is electrically connected to the generator means via a controllable switch.

12. The wind turbine facility according to claim 1, wherein at least part of the power dissipation/storage means is electrically connected to an intermediate DC circuit of the electric power converter via a controllable switch.

13. The wind turbine facility according to claim 1, wherein the power dissipation/storage means comprises a first part being electrically connected to the generator means via a first controllable switch, and a second part being electrically connected to an intermediate DC circuit of the electric power converter via a second controllable switch.

14. The wind turbine facility according to claim 1, wherein the power dissipation/storage means comprises a resistor for dissipating electrical energy.

15. The wind turbine facility according to claim 1, wherein the power dissipation/storage means comprises capacitive means, such as a capacitor bank, for storing electrical energy.

16. A method for operating a wind turbine facility adapted to deliver electrical energy to an associated power supply grid during a grid fault, such as a low-voltage ride through event, the wind turbine facility comprising power dissipation/storage means being adapted to dissipate or store electrical energy exceeding an amount to be delivered to the associated power supply grid during the grid fault, the method comprising the step of operating the wind turbine facility in accordance with an allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage means of the wind turbine facility by ensuring that a total amount of electrical energy generated by the wind turbine facility does not exceed a sum of the allowed amount and the amount to be delivered to the power supply grid.

17. The method according to claim 16, wherein the allowed amount of electrical energy is determined from a thermal capacity of a power dissipation element of the power dissipation/storage means.

18. The method according to claim 16, wherein the allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage means is determined on a regular basis.

19. The method according to claim 16, wherein the allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage means is determined in response to specific events, such as during grid faults or in periods following such grid faults.

20. The method according to claim 16, further comprising the step of applying electrical energy stored in the power storage means for energising a part of or parts of the wind turbine facility after stoppage of said wind turbine facility.

21. A method for operating a wind turbine facility adapted to deliver electrical energy to an associated power supply grid, the wind turbine facility comprising power dissipation/storage means being adapted to dissipate or store electrical energy, the method comprising the step of operating the wind turbine facility in accordance with an allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage means of the wind turbine facility by ensuring that a total amount of electrical energy generated by the wind turbine facility does not exceed the allowed amount of electrical energy.

22. The method according to claim 21, wherein the allowed amount of electrical energy is determined from a thermal capacity of a power dissipation element of the power dissipation/storage means.

23. The method according to claim 21, wherein the allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage means is determined on a regular basis.

24. The method according to claim 21, wherein the allowed amount of electrical energy that can be dissipated or stored in the power dissipation/storage means is determined in response to specific events, such as during grid faults or in periods following such grid faults.

25. The method according to claim 21, further comprising the step of applying electrical energy stored in the power storage means for energising a part of or parts of the wind turbine facility after stoppage of said wind turbine facility.