WIND TURBINE GENERATOR, ACTIVE DAMPING METHOD THEREOF, AND WINDMILL TOWER

• US 20100187820A1
• Filed: 03/19/2010
• Published: 07/29/2010
• Est. Priority Date: 02/27/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: WAKASA, Tsuyoshi, HAYASHI, Yoshiyuki, SHIBATA, Masaaki, IDE, Kazunari
• Granted Patent: US 8,026,623 B2
• Time in Patent Office: Days
• US Class Current: 290/44
• CPC Class Codes: F03D 7/0224 Adjusting blade pitch
• CPC Class Codes: F03D 7/0296 to prevent, counteract or reduce noise emissions
• CPC Class Codes: F03D 7/043 characterised by the type of control logic
• CPC Class Codes: F03D 9/25 the apparatus being an electrical generator F03D9/22 takes precedence
• CPC Class Codes: F05B 2260/71 as a function of flow velocity
• CPC Class Codes: F05B 2260/74 by turning around an axis perpendicular the rotor centre line
• CPC Class Codes: F05B 2260/821 Parameter estimation or prediction
• CPC Class Codes: F05B 2260/96 Preventing, counteracting or reducing vibration or noise
• CPC Class Codes: F05B 2270/1021 by keeping it below damagingly high values
• CPC Class Codes: F05B 2270/309 Rate of change of parameters
• CPC Class Codes: F05B 2270/334 Vibration measurements
• CPC Class Codes: F05B 2270/404 active, predictive, or anticipative
• CPC Class Codes: F05B 2270/807 Accelerometers
• CPC Class Codes: Y02B 10/30 Wind power
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A wind turbine generator, an active damping method thereof, and a windmill tower in which vibrations of the wind turbine generator itself or the windmill tower can be reduced at low cost are provided. The acceleration due to vibrations of a nacelle is detected with an accelerometer attached to the nacelle. In an active damping unit, a pitch angle of windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle is calculated on the basis of the acceleration, and the pitch angle is output as a blade-pitch-angle command δθ* for damping. On the other hand, in a pitch-angle control unit, a pitch angle of the windmill blades for controlling the output to be a predetermined value is calculated, and the pitch angle is output as a blade-pitch-angle command θ* for output control. The blade-pitch-angle command δθ* for damping is combined with the blade-pitch-angle command θ* for output control using a subtracter. The pitch angle of the windmill blades is controlled on the basis of the resulting blade-pitch-angle command after combining.

Claims

1. A wind turbine generator including a pitch-angle control mechanism for controlling a pitch angle of windmill blades on the basis of a blade-pitch-angle command, the wind turbine generator comprising:

an accelerometer, attached to a nacelle, for detecting the acceleration due to vibrations of the nacelle; and

an active damping unit for calculating a pitch angle of the windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle on the basis of the acceleration detected with the accelerometer and for outputting a blade-pitch-angle command to the pitch-angle control mechanism.

2. The wind turbine generator according to claim 1, wherein the active damping unit includes

a speed estimation unit for estimating a speed from the acceleration detected with the accelerometer, and

a control unit for calculating a pitch angle of the windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle on the basis of the speed output from the speed estimation unit.

7. The wind turbine generator according to claim 1, wherein the active damping unit includes a limiter for limiting the pitch angle of the windmill blades or the angular speed of the pitch angle of the windmill blades to a predetermined range.

3. The wind turbine generator according to claim 3, wherein the speed estimation unit integrates the acceleration detected with the accelerometer to calculate the speed.

4. The wind turbine generator according to claim 3, wherein the control unit includes a phase-lead compensator for advancing the phase of the speed output from the speed estimation unit by a predetermined amount, and calculates the pitch angle on the basis of the speed obtained after the phase-lead compensation.

6. The wind turbine generator according to claim 3, wherein the control unit includes any one of a proportional controller, a proportional-integral controller, a proportional-integral-derivative controller, a linear-quadratic regulator, and a linear-quadratic Gaussian regulator to which the speed estimated by the speed estimation unit is input to calculate the pitch angle.

5. The wind turbine generator according to claim 5, wherein the control unit includes a phase-lag compensator for delaying the phase of the speed output from the phase-lead compensator by a predetermined amount, and calculates the pitch angle on the basis of the speed obtained after the phase-lag compensation.

8. An active damping method of a wind turbine generator including

a pitch-angle control mechanism for controlling a pitch angle of windmill blades on the basis of a blade-pitch-angle command, and

an accelerometer, attached to a nacelle, for detecting the acceleration due to vibrations of the nacelle, the active damping method comprising:

an active damping step of calculating a pitch angle of the windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle on the basis of the acceleration detected with the accelerometer and outputting a blade-pitch-angle command to the pitch-angle control mechanism.

9. An active damping method of a wind turbine generator including a pitch-angle control mechanism for controlling a pitch angle of windmill blades on the basis of a blade-pitch-angle command, and

an accelerometer, attached to a nacelle, for detecting the acceleration due to vibrations of the nacelle, the active damping method comprising:

an active damping step of calculating a pitch angle of the windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle on the basis of the acceleration detected with the accelerometer and outputting a blade-pitch-angle command for damping;

a pitch-angle control step of calculating a pitch angle of the windmill blades for controlling the output of the wind turbine generator to be a predetermined value on the basis of wind speed, the rotational speed of a windmill rotor, or the output of the wind turbine generator and outputting a blade-pitch-angle command for output control; and

an addition step of supplying the pitch-angle control mechanism with a blade-pitch-angle command obtained by combining the blade-pitch-angle command for damping in the active damping step with the blade-pitch-angle command for output control in the pitch-angle control step.

10. The active damping method of a wind turbine generator according to claim 9, wherein the active damping step includes

a speed estimation step of estimating a speed from the acceleration detected with the accelerometer, and

a control step of calculating a pitch angle of the windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle on the basis of the speed estimated in the speed estimation step.

11. The active damping method according to claim 11, wherein the speed estimation step integrates the acceleration detected with the accelerometer to calculate the speed.

12. The active damping method of a wind turbine generator according to claim 11, wherein the control step includes a phase-lead compensation step of advancing the phase of the speed estimated by the speed estimation step by a predetermined amount and calculates the pitch angle on the basis of the speed obtained after the phase-lead compensation.