METHOD FOR STOPPING A WIND TURBINE IN TWO STAGES

• US 20100068057A1
• Filed: 09/17/2009
• Published: 03/18/2010
• Est. Priority Date: 09/18/2008
• Status: Abandoned Application

• Current Assignee: Gamesa Innovation and Technology SL (Siemens AG)
• Original Assignee: Gamesa Innovation and Technology SL (Siemens AG)
• Inventors: Friedrich, Michael, Andersen, Rasmus
• Application Number:
  US12/561,316
• Publication Number:
  US 20100068057A1
• Time in Patent Office: Days
• US Class Current: 416/1
• CPC Class Codes: F03D 7/0244 for braking
• CPC Class Codes: F03D 7/0248 by mechanical means acting on the power train
• CPC Class Codes: F03D 7/0268 Parking or storm protection
• CPC Class Codes: F05B 2260/901 using aerodynamic forces, i.e. lift or drag
• CPC Class Codes: F05B 2260/902 using frictional mechanical forces
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A method for stopping a pitch controlled wind turbine comprising a rotor with at least one blade (11), a mechanical brake (31) on the high speed shaft, a pitch system ((21, 23, 25) for adjusting the blade pitch angle, that includes: a) a first stage using the pitch system (21, 23, 25) for slowing down the rotor; b) a second stage using both the pitch system (21, 23, 25) and the mechanical brake (31) for stopping the rotor. The second stage begins when one of the following conditions takes place: the high speed shaft rotational speed is under a predefined value So; a predefined time delay To with respect to the beginning of the first stage is reached; a predefined high speed shaft torque level TLo is reached.

Claims

1. A method for stopping a pitch controlled wind turbine comprising a rotor with at least one blade (11), a mechanical brake (31) on the high speed shaft, a pitch system (21, 23, 25) for adjusting the blade pitch angle, characterized in that it includes:

a) a first stage using the pitch system (21, 23, 25) for slowing down the rotor;

b) a second stage using both the pitch system (21, 23, 25) and the mechanical brake (31) for stopping the rotor.

2. A method for stopping a pitch controlled wind turbine according to claim 1, characterized in that the second stage begins when one of the following conditions takes place:

the high speed shaft rotational speed is under a predefined value So;

a predefined time delay To with respect to the beginning of the first stage is reached;

a predefined high speed shaft torque level TLo is reached.

3. A method for stopping a pitch controlled wind turbine according to claim 1, characterized in that the second stage begins when the first of the following conditions takes place:

the high speed shaft rotational speed is under a predefined value So;

a predefined time delay To with respect to the beginning of the first stage is reached.

4. A method for stopping a pitch controlled wind turbine according to claim 1, characterized in that the second stage begins when the first of the following conditions takes place:

the high speed shaft rotational speed is under a predefined value So;

a predefined time delay To with respect to the beginning of the first stage is reached;

a predefined high speed shaft torque level TLo is reached.

5. A method for stopping a pitch controlled wind turbine according to claim 2-4, characterized in that said high speed shaft rotational speed predefined value So is comprised in the range of 10% to 15% the nominal rotational speed.

7. A method for stopping a pitch controlled wind turbine according to claim 2, characterized in that said high speed shaft torque level predefined value TLo is 30% of the nominal torque.

8. A method for stopping a pitch controlled wind turbine according to claim 3, characterized in that said high speed shaft rotational speed predefined value So is comprised in the range of 10% to 15% the nominal rotational speed.

9. A method for stopping a pitch controlled wind turbine according to claim 4, characterized in that said high speed shaft rotational speed predefined value So is comprised in the range of 10% to 15% the nominal rotational speed.

10. A method for stopping a pitch controlled wind turbine according to claim 3, characterized in that said predefined time delay To is comprised between 8 and 35 sec.

11. A method for stopping a pitch controlled wind turbine according to claim 4, characterized in that said predefined time delay To is comprised between 8 and 35 sec.

12. A method for stopping a pitch controlled wind turbine according to claim 4, characterized in that said high speed shaft torque level predefined value TLo is 30% of the nominal torque.

6. A method for stopping a pitch controlled wind turbine according to claim 24, characterized in that said predefined time delay To is comprised between 8 and 35 sec.