JP6165053B2 - Wind power generator - Google Patents

Description

  The present invention relates to a technique for reducing tower vibration in a wind turbine generator.

  In recent years, there is concern about global warming and depletion of fossil fuels due to carbon dioxide emissions, and there is a need to reduce emissions of carbon dioxide and to reduce dependence on fossil fuels. In order to reduce carbon dioxide emissions and reduce dependence on fossil fuels, it is effective to introduce a power generation system that uses renewable energy such as wind power and sunlight.

  Among the power generation systems using renewable energy, the wind power generation system is attracting attention as a relatively stable power generation system because it does not receive direct output change due to solar radiation unlike the solar power generation system. In addition, wind power generation systems installed on the ocean with higher wind speed and less change in wind speed compared to the ground have attracted attention as a powerful power generation system.

  In constructing a wind power generation system, means for suppressing vibrations of towers constituting the wind power generation system is necessary. The reason is as follows. A rotor composed of blades and a hub to which the blades are connected is connected to a nacelle installed on the tower. In a wind power generation system capable of outputting several MW, the tower is several tens of meters high. Therefore, the force (moment) applied to the tower greatly changes due to the change in the wind speed received by the rotor, and the tower vibrates. Due to this vibration, fatigue builds up in the tower, which may shorten the life of the tower.

  As a background art related to the technical field, there is a technique such as Patent Document 1, for example. Patent Document 1 discloses a wind power generation apparatus having a pitch angle control mechanism that controls a pitch angle of a wind turbine blade based on a blade pitch angle command, and is attached to a nacelle and detects an acceleration of vibration of the nacelle. And calculating a pitch angle of the windmill blade for generating a thrust force on the windmill blade so as to cancel the vibration of the nacelle based on the acceleration detected by the accelerometer, and giving a blade pitch angle command to the pitch angle. A wind turbine generator having active vibration control means for outputting to a control mechanism is disclosed.

Japanese Patent No. 4599350

  In Patent Document 1, in order to suppress the vibration of the tower, the thrust signal applied to the rotor is adjusted by controlling the pitch angle of the blade using the output signal of the acceleration sensor installed in the nacelle, and the tower vibration is controlled. Means to suppress are disclosed. According to the technique described in Patent Document 1, it is possible to suppress tower vibration by providing a virtual damper term corresponding to the speed of tower vibration.

  However, when the technique disclosed in Patent Document 1 is applied to a floating wind power generation system, there are the following problems. In the floating type, the inclination angle of the tower is larger than that of the landing type. When an acceleration sensor is used, the acceleration due to gravity is also detected when the tower tilt angle increases. When the pitch angle command value is determined based on the acceleration including the influence of gravity, the pitch angle command value component determined by the acceleration other than the tower vibration exists, so the pitch angle command value is different from the original purpose. Based on this, the pitch angle of each blade may be determined. As a result, the technique disclosed in Patent Document 1 may not properly suppress tower vibration.

  Accordingly, an object of the present invention is to provide a wind turbine generator having excellent durability by effectively suppressing the vibration of the tower during power generation and reducing the fatigue of the tower in the wind turbine generator. It is another object of the present invention to provide an economical wind power generator that can suppress the additional cost for reinforcing the tower.

In order to solve the above problems, the present invention provides a tower that is installed on the ground or the ocean and serves as a support for a wind power generator, a nacelle that is provided on the tower and includes a generator inside, and a nacelle of the nacelle. A wind turbine generator provided at one end and including a plurality of blades and a hub that receives wind to convert into rotational energy, an inclination angle detecting means for detecting the inclination of the nacelle, and the blade Pitch angle control means for adjusting the pitch angle of the blade with respect to the hub, and based on the inclination angle of the nacelle detected by the inclination angle detection means, the pitch angle control means controlling the pitch angle, the pitch angle control means, an average value of the pitch angle at the rotational position near to the blade from the position of the base of the tower is the highest The absolute value of the deviation with respect to the pitch angle mean value, and controls the pitch angle to be greater than the absolute value of the deviation to the pitch angle mean value of the pitch angle of the other rotating position.

  ADVANTAGE OF THE INVENTION According to this invention, the wind power generator excellent in durability can be implement | achieved in a wind power generator by suppressing the vibration of the tower at the time of electric power generation effectively, and reducing the fatigue of a tower. Moreover, the additional cost for tower reinforcement can be suppressed and the wind power generator excellent in economy can be implement | achieved.

It is a figure which shows schematic structure of the wind power generator which concerns on one Embodiment of this invention. It is a figure which shows the nacelle and inclination | tilt angle sensor of the wind power generator which concern on one Embodiment of this invention. It is a figure which shows the relationship between the inclination-angle of the nacelle of the wind power generator which concerns on one Embodiment of this invention, and the displacement of a horizontal direction. It is a figure which shows the outline of the secondary vibration system assumed to the representative point of the nacelle and tower of the wind power generator which concerns on one Embodiment of this invention. It is a block diagram which shows the system outline | summary of the wind power generator which concerns on one Embodiment of this invention. It is a block diagram which shows the outline | summary of the displacement speed calculating part of the wind power generator which concerns on one Embodiment of this invention. It is a block diagram which shows the outline | summary of the displacement speed calculating part of the wind power generator which concerns on one Embodiment of this invention. It is a block diagram which shows the outline | summary of the displacement speed calculating part of the wind power generator which concerns on one Embodiment of this invention. It is a block diagram which shows the outline | summary of the pitch angle command value calculating part of the wind power generator which concerns on one Embodiment of this invention. It is a block diagram which shows the outline | summary of the independent pitch angle deviation calculating part of the wind power generator which concerns on one Embodiment of this invention. It is a flowchart which shows the calculation flow of the tower damping control of the wind power generator which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the wind power generator which concerns on one Embodiment of this invention. It is a figure which shows the relationship between the distortion of the tower of the wind power generator which concerns on one Embodiment of this invention, and the displacement of a horizontal direction. It is a block diagram which shows the system outline | summary of the wind power generator which concerns on one Embodiment of this invention. It is a block diagram which shows the outline | summary of the displacement speed calculating part of the wind power generator which concerns on one Embodiment of this invention. It is a block diagram which shows the outline | summary of the displacement speed calculating part of the wind power generator which concerns on one Embodiment of this invention. It is a block diagram which shows the outline | summary of the displacement speed calculating part of the wind power generator which concerns on one Embodiment of this invention. It is a flowchart which shows the calculation flow of the tower damping control of the wind power generator which concerns on one Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

<< Schematic Configuration of Example 1 >>
First, a schematic configuration of the wind turbine generator according to the present embodiment will be described with reference to FIG. FIG. 1 shows an overall schematic configuration of the wind turbine generator 1 of the present embodiment. The wind turbine generator 1 includes a rotor 4 including a plurality of blades 2 and a hub 3 that connects the plurality of blades 2. Although not shown in the figure, the rotor 4 is connected to one end of the nacelle 6 via a rotating shaft, and the position of the blade 2 can be changed by rotating. When the blade 2 receives wind, the rotor 4 rotates, and although not shown in the figure, electric power can be generated by rotating a generator provided in the nacelle. Each of the blades 2 is provided with a pitch angle control means, that is, a pitch actuator 5 that can adjust a positional relationship between the blade 2 and the hub 3, that is, a blade angle called a pitch angle. By changing the pitch angle of the blade 2 using the pitch actuator 5, the rotational energy of the rotor with respect to the wind can be changed. Thereby, the electric power generated by the wind power generator 1 can be controlled while controlling the rotational speed of the rotor 4 in a wide wind speed region. The nacelle 6 is installed on a tower 8 serving as a support part of the wind power generator, and the tower 8 is installed at a base, and is installed at a predetermined position on the ground or the ocean, although not shown in the figure. The wind turbine generator 1 further includes an inclination angle sensor 7 that can measure the inclination angle of the nacelle 6 in the nacelle 6. Further, the wind turbine generator 1 includes a controller 9, and tower damping control for reducing vibration generated in the tower 8 by adjusting the pitch actuator 5 based on the output signal of the tilt angle sensor 7 is a program form. Implemented in. In FIG. 1, the controller 9 is illustrated as being installed outside the nacelle 6 or the tower 8. However, the controller 9 is not limited thereto, and the nacelle 6 or the tower 8 or other predetermined position, or the wind power generator 1 may be installed outside.

<< Nacelle inclination angle in Example 1 >>
FIG. 2 is a diagram illustrating an inclination angle measured by an inclination angle sensor 7 installed at a predetermined position of the nacelle 6 of the wind power generator 1. X ₀ axis coincides with the horizontal axis, X ₀ vertical Z ₀ axis to the axis, and X ₀ have the axis and the intersection of Z ₀ axis, and the reference coordinate system sigma ₀ composed of Y ₀ axis toward the paper back In this case, the tilt angle sensor 7 is installed in the coordinate system Σ ₁ constituted by the X ₁ axis and the Z ₁ axis existing in a plane parallel to the paper surface and the Y ₁ axis whose direction coincides with the Y ₀ axis. . The tilt angle sensor 7 measures the rotation angle φ around the coordinate system sigma ₁ with respect to the coordinate system sigma ₀ Y ₀ axis (Y ₁ axis). Since the tilt angle sensor 7 is physically installed in the nacelle 6 and moves in the same manner as the nacelle 6, the rotation angle φ coincides with the tilt angle of the nacelle 6.

<< Determination of Tower Displacement in Example 1 >>
FIG. 3 is a schematic diagram showing the vibration displacement of the tower 8 when the wind power generator 1 receives wind energy to generate power. Assuming a form in which the tower 8 is a rigid body and is inclined at the base of the tower 8, the displacement x of the tower 8 can be determined by the following equation with respect to the inclination angle φ shown in FIG.

Here, h indicates the height of the tower.

<< Assumed behavior of tower vibration in Example 1 >>
FIG. 4 shows a secondary vibration model assumed as a representative point of the tower 8. Hereinafter, in this embodiment, it is assumed that the vibration of the tower 8 is only the primary vibration mode. As shown in FIG. 4, a mass point of mass M is assumed as a representative point of the tower 8, and this vibration characteristic has an elastic characteristic K and a viscous characteristic D, and is based on the displacement x defined above. F indicates a longitudinal force (thrust force) applied to the tower 8. This thrust force is a force generated when the rotor 4, the nacelle 6 and the tower 8 receive wind. The magnitude of the thrust force can be changed by adjusting the pitch angle of each blade.

≪Tower damping control in Example 1≫
Hereinafter, an example of tower damping control that is mounted on the controller 9 of the wind turbine generator 1 and reduces the vibration of the tower 8 based on the displacement speed vx that is a result of differentiating the displacement x will be described with reference to FIGS. Will be described.

FIG. 5 is a block diagram illustrating an outline of the tower vibration suppression control and the control target in the first embodiment. The block diagram shown in FIG. 5 includes a tower vibration suppression control unit 501 and a control target unit 502. The tower vibration suppression control unit 501 includes a displacement speed calculation unit 51, a displacement speed deviation calculation unit 52, and a pitch angle command value calculation unit 53. The displacement speed calculation unit 51 calculates the displacement speed vx of the tower 8 based on the inclination angle φ that is the output signal of the inclination angle sensor 7. The displacement speed deviation calculator 52 subtracts the displacement speed vx, which is the output of the displacement speed calculator 51, from the displacement speed target value vx ^* to calculate the displacement speed deviation Δvx. The pitch angle command value calculator 53 calculates a pitch angle command value θ ^* _c for reducing the vibration of the tower 8 based on the displacement speed deviation Δvx. Here, the pitch angle command value is defined as a command value that gives a similar command to all pitch actuators 5 of a plurality of blades 2. The control target unit 502 includes a blade characteristic unit 54, an addition unit 55, a tower vibration characteristic unit 56, and an inclination angle sensor characteristic unit 57. The blade characteristic unit 54 determines a thrust force (thrust force by tower damping control) ΔF generated in the tower 8 based on the pitch angle command value θ ^* _c for reducing the vibration of the tower 8. The adding unit 55 adds the basic thrust force F ₀ and the thrust force ΔF by tower vibration suppression control, and calculates all the thrust forces (total thrust force) F applied to the tower 8. Here, the basic thrust force F ₀ is the thrust force generated when the wind power generator 1 controls the pitch angle in order to control the generated power according to the wind speed, that is, the thrust force when the tower damping control is not executed. Indicates. The tower vibration characteristic unit 56 is a behavior of a secondary vibration model of a mass point assumed as a representative point of the tower 8 as shown in FIG. 4, and determines the displacement x of the tower 8 based on the total thrust force F. The inclination angle sensor characteristic unit 57 indicates the output characteristic of the inclination angle sensor 7 installed in the nacelle 6 above the tower 8.

  Hereinafter, each example which comprises the tower damping control part 501 and the control object part 502 is demonstrated.

First, the tower vibration suppression control unit 501 will be described. FIG. 6 is a diagram illustrating a first embodiment of the displacement speed calculation unit 51 in the first embodiment. The displacement speed calculation unit 51 in the present embodiment includes a tower displacement calculation unit 61 and a differential calculation unit 62. The tower displacement calculator 61 determines the displacement x based on Equation 1 based on the inclination angle φ that is the output signal of the inclination angle sensor 7. The differential operation unit 62 determines the displacement speed vx by differentiating the displacement x with time. FIG. 7 is a diagram illustrating a second embodiment of the displacement speed calculation unit 51 in the first embodiment. The displacement speed calculation unit 51 in the present embodiment is obtained by adding a noise removal processing unit 71 to the preceding stage of the first embodiment described above. The noise removing unit 71 has a characteristic of removing noise included in the output signal of the tilt angle sensor 7, and may have a transfer characteristic of a low-pass filter. In the present embodiment, the after-noise removal inclination angle φ ₁ is determined based on the inclination angle φ of the tower 8. Thereafter, the displacement x is determined based on Equation 1, and the displacement speed vx is determined by differentiation. FIG. 8 is a diagram illustrating a third embodiment of the displacement speed calculation unit 51 in the first embodiment. The displacement speed calculation unit 51 in the present embodiment has a configuration in which a bandpass filter characteristic unit 81 is added between the noise removal processing unit 71 and the tower displacement calculation unit 61 with respect to the second embodiment. The above-described noise removal processing unit 71 is executed on the inclination angle φ that is an output signal of the inclination angle sensor 7 to determine the inclination angle φ ₁ after noise removal. The band-pass filter characteristic unit 81 executes processing for extracting only a predetermined frequency band from the noise-removed inclination angle φ ₁ and determines the predetermined band inclination angle φ ₂ . The predetermined frequency band may be a natural frequency band of the primary vibration mode of the tower 8 or may be a frequency band generated by a generator or a fan constituting the wind power generator 1. Based on the determined predetermined band inclination angle φ ₂ , the tower displacement calculation unit 61 determines the displacement x based on Equation 1, and the differentiation calculation unit 62 differentiates the displacement x to determine the displacement speed vx. The displacement speed deviation calculation unit 52 calculates the displacement speed deviation Δvx based on the following equation based on the displacement speed vx and the displacement speed target value vx ^* .

FIG. 9 is a block diagram illustrating an example of the pitch angle command value calculation unit 53. In the embodiment of FIG. 9, the proportional component and the gain of the gain K _p relative to an input displacement speed deviation Δvx is based on the configured PD controlled by differential component of K _D, calculates a pitch angle command value theta ^* _c . The following equation shows the transfer function of PD control.

Next, an example of the control target unit 502 will be described below. The blade characteristic unit 54 determines the thrust force ΔF by tower vibration suppression control from the pitch angle command value θ ^* c based on the following equation.

Equation 4 shows a characteristic in which the thrust force ΔF by the tower vibration suppression control is proportional to the pitch angle command value θ ^* _c , but is not limited thereto, and may be an inverse proportion or a characteristic of a polynomial.
Since the tower vibration characteristic unit 56 assumes a secondary vibration model as shown in FIG. 4, the following characteristic is assumed between the displacement x of the tower 8 and the total thrust force F.

The inclination angle sensor characteristic unit 57 is determined by the deformation characteristic of the tower 8 and the characteristic of the inclination angle sensor 7. Assuming the relationship of FIG. 3 between the tilt angle φ and the displacement x, the tilt angle φ is determined based on the following equation.

≪Effect when PD control is applied to tower vibration suppression control≫
Hereinafter, the detail regarding the effect at the time of applying PD control to tower vibration suppression control is demonstrated. The following relationship is established between the total thrust force F, the thrust force ΔF by the tower damping control, and the basic thrust force F ₀ .

Here, from the equations 3 and 4, the following relationship is established between the displacement speed change Δvx and the thrust force ΔF by the tower damping control.

Here, the displacement speed deviation Δvx is expressed by Equation 2, but in order to suppress the vibration of the tower 8,

Therefore, Equation 2 is expressed by the following equation.

From the equations 8 and 10, the following equation is obtained.

The following formula obtained from Equation 5

Substituting Equation 7 and Equation 11 into the following equation yields:

For the following equation, which is the characteristic before applying the tower vibration suppression control of the first embodiment,

In Expression 13, the weight term of the first term on the right side and the attenuation term of the second term on the right side are increased. This indicates that the tower weight and damping characteristics are virtually increased by the pitch angle command value by the tower damping control. Due to the above effect, the vibration of the tower 8 can be reduced.

≪Improved effect of tower vibration control by independent pitch control≫
FIG. 10 shows a block diagram of control (tower vibration control by independent pitch angle command) that can improve the effect of tower vibration control by independently determining the pitch angle command value. This control is composed of an independent pitch angle deviation calculating unit 101 and an adding unit 102 for determining the independent pitch angle deviation θ ^* _i of each blade from the pitch angle command value θ ^* _c determined by the tower vibration suppression control described above. The The independent pitch angle deviation calculating unit 101 determines the independent pitch angle deviation θ ^* _i based on the following equation.

Here, i is the blade number, ψ _i is the rotor rotational position of each blade (referenced to the direction perpendicular to the horizontal plane), and ψ ₀ is an offset value considering the delay from the pitch angle command to the operation. Here, f (θ ^* _c ) may be proportional to the pitch angle command value θ ^* _c as in the following equation, or may be based on a polynomial, and is not limited to this. .

As shown in Expression 15, by using cos for the independent pitch angle deviation θ ^* _i , it is possible to reduce the thrust force that promotes the vibration of the tower 8 caused by the wind force with the highest blade 2 position. Further, in a situation where the position of the blade 2 is the lowest and overlaps with the tower, the thrust force is weaker than when the blade 2 is present at another position, and thus a moment that increases the vibration of the tower 8 is generated. In order to suppress this, when the position of the blade 2 is at the lowest rotational position, in order to increase the influence of the thrust force change due to the pitch angle command value, the operation amount of the blade 2 is adjusted using the cos function. Adjust to the higher position and in the opposite direction. In the tower vibration suppression control by the independent pitch angle command, the independent pitch angle command value of each blade 2 is finally calculated according to the following formula.

In the tower vibration suppression control in the first embodiment described above, a plurality of constants are used. However, these constants may be determined by simulation or actual machine test, or determined by a predetermined design method. There may be. Moreover, it may change suitably according to a predetermined state instead of a constant.

<< Flowchart of tower vibration suppression control in embodiment 1 >>
FIG. 11 shows an example of a flowchart of tower vibration suppression control in the first embodiment. In step S1101, the inclination angle φ is determined based on the output signal of the inclination angle sensor 7, and the process proceeds to the next step. In subsequent step S1102, the vibration displacement speed vx of the tower 8 is determined based on the inclination angle φ, and the process proceeds to the next step. In step S1103, the pitch angle command value θ ^* _c of each blade 2 is determined based on the displacement speed vx of the tower 8, and the process proceeds to the next step. In step S1104, an independent pitch angle command value θ ^* _i is determined based on the pitch angle command value θ ^* _c , and a series of processing ends.

The flowchart of the tower vibration suppression control in the present embodiment is not limited to this. For example, the step S1104 for determining the independent pitch angle command value θ ^* _i is omitted, and even if the processing is only from step S1101 to step S1103, An effect can be obtained.

<< Schematic Configuration of Example 2 >>
Below, schematic structure of the wind power generator concerning a present Example is demonstrated using FIG. 12 thru | or FIG. FIG. 12 shows an overall schematic configuration of the wind turbine generator 1 of the present embodiment. The blade 2, the hub 3, the rotor 4, the pitch actuator 5, the nacelle 6, and the tower 8 are the same as those in the first embodiment described with reference to FIG. In the second embodiment, strain detecting means for detecting the strain amount of the tower 8, that is, a plurality of strain sensors 12 (denoted by 12 a, 12 b, and 12 c in FIG. 12) are provided at predetermined positions on the ground surface side of the tower 8. Further, the wind turbine generator 1 is equipped with a controller 120 at an appropriate position, and the controller 120 is given a command to the pitch actuator 5 based on the output signals of these strain sensors 12, thereby reducing the vibration generated in the tower 8. Tower damping control that can be done is implemented in the form of a program. The tower vibration suppression control mounted on the controller 120 determines the amount of deformation of the tower 8 from the output signal of the strain sensor 12, and instructs the pitch actuator 5 to adjust the pitch angle of the plurality of blades 2 based on the amount of deformation. The pitch angle command value which is a value is determined. In FIG. 12, the controller 120 is described outside the nacelle 6 and the tower 8. However, the controller 120 is not limited to this, and may be provided at a predetermined position of the nacelle 6 or a predetermined position of the tower 8. It may be good or installed outside the wind power generator 1.

<< Determination of Tower Displacement in Example 2 >>
FIG. 13 is a diagram illustrating the relationship between the vibration displacement of the tower 8 and the strain amount measured by the strain sensor 12 when the wind power generator 1 receives wind energy to generate power. In FIG. 13, x is a horizontal displacement of the tower 8, δ is a deformation amount of the tower 8 of the strain sensor 12 mounting portion determined based on an output signal of the strain sensor 12 installed in the tower 8, and φ is the tower 8. The inclination angle of the tower 8 and h ₁ when a portion other than the attachment portion of the strain sensor 12 is assumed to be a rigid body, respectively indicate the length from the attachment position of the nacelle 6 to the attachment position of the strain sensor 12 in the tower 8. However, the tower length h ₁ is a vertical length in a state where wind energy is not input to the rotor 4, the nacelle 6, and the tower 8, that is, a state where no wind is received.
In this embodiment, if the inclination angle φ is small, the property that the inclination angle φ can be approximated by the deformation amount δ is used, the proportional gain G ₃ is used, and the displacement x of the tower 8 is calculated based on the following equation. .

The proportional gain G ₃ may be determined from the geometric relationship shown in FIG. 13 or may be determined based on actually measured data. Moreover, it is not limited to Equation 18, but may be determined based on a polynomial of deformation amount δ. Here, the deformation amount δ is determined based on a plurality of output signals of a plurality of strain sensors 12 installed. The output signal of the strain sensor 12 may be filtered and the maximum value of the signal after noise removal may be used, or the deformation form of the tower 8 at the position where the strain sensor 12 is attached is estimated from the signal after noise removal, without deformation The amount of deformation from the state may be determined.

<< Assumed behavior of tower vibration in Example 2 >>
Since the assumed behavior of the tower vibration in the second embodiment assumes the secondary vibration model shown in FIG. 4 as in the first embodiment, detailed description thereof is omitted.

≪Tower damping control in Example 2≫
Hereinafter, tower vibration suppression control implemented in the controller 120 in the second embodiment will be described with reference to FIGS. 14 to 18.

  The difference between the tower vibration suppression control in the first embodiment and the tower vibration suppression control in the second embodiment is that the input of the tower vibration suppression control uses the deformation amount δ. Using this deformation amount δ, the displacement speed vx of the tower 8 is determined, and based on this, the pitch angle command value to be output to the pitch actuator 5 is determined. FIG. 14 is a block diagram illustrating an outline of a tower vibration suppression control unit and a control target according to the second embodiment. The block diagram shown in FIG. 14 includes a tower vibration suppression control unit 1401 and a control target unit 1402. The tower damping control unit 1401 includes a displacement speed calculation unit 141, a displacement speed deviation calculation unit 52, and a pitch angle command value calculation unit 53. The displacement speed calculation unit 141 calculates the displacement speed vx of the tower 8 based on the deformation amount δ that is an output signal of the strain sensor 12. Since the displacement speed deviation calculation unit 52 and the pitch angle command value calculation unit 53 are the same as those in the first embodiment, description thereof is omitted.

  The control target unit 1402 includes a blade characteristic unit 54, an addition unit 55, a tower vibration characteristic unit 56, and a strain sensor characteristic unit 142. Since the blade characteristic unit 54, the adding unit 55, and the tower vibration characteristic unit 56 are the same as those in the first embodiment, the description thereof is omitted. A strain sensor characteristic unit 142 indicates output characteristics of the strain sensor 12 installed in the nacelle 6 above the tower 8. Hereinafter, the displacement speed calculation unit 141 and the strain sensor characteristic unit 142 which are different from the first embodiment will be described.

FIG. 15 shows a first embodiment of the displacement speed calculator 141 in the second embodiment. The displacement speed calculation unit 141 in the present embodiment includes a tower displacement calculation unit 151 and a differentiation calculation unit 152. The tower displacement calculation unit 151 determines the displacement x of the tower 8 using Equation 18 based on the deformation amount δ that is the output signal of the strain sensor 12. The differential calculation unit 152 determines the displacement speed vx by time-differentiating the displacement x as in the first embodiment. FIG. 16 is a diagram illustrating a second embodiment of the displacement speed calculation unit 141 according to the second embodiment. The displacement speed calculation unit 141 in the present embodiment is obtained by adding a noise removal processing unit 161 to the previous stage of the first embodiment described above. The noise removal processing unit 161 has a characteristic of removing noise included in the output signal of the tilt angle sensor 7, and may have a transfer characteristic of a low-pass filter. In the present embodiment, the post-noise removal deformation amount δ ₁ is determined based on the deformation amount δ of the tower 8. Thereafter, the displacement x is determined based on Equation 18, and the displacement speed vx is determined by differentiation. FIG. 17 shows a third embodiment of the displacement speed calculator 141 in the second embodiment. The displacement speed calculation unit 141 according to this embodiment has a configuration in which a bandpass filter characteristic unit 171 is added between the noise removal processing unit 161 and the tower displacement calculation unit 151 with respect to the second embodiment. The above-described noise removal processing unit 161 is executed on the deformation amount δ that is an output signal of the strain sensor 12 to determine the post-noise removal deformation amount δ ₁ . The band-pass filter characteristic unit 171 executes processing for extracting only a predetermined frequency band from the post-noise removal deformation amount δ ₁ and determines the predetermined band deformation amount δ ₂ . The predetermined frequency band may be a natural frequency band of the primary vibration mode of the tower 8 or may be a frequency band generated by a generator or a fan constituting the wind power generator 1. Based on the determined predetermined band inclination angle φ ₂ , the displacement x is determined by the tower displacement calculator 151 based on Equation 18, and then the displacement x is determined by differentiating the displacement x by the differential calculator 152. The strain sensor characteristic unit 142 illustrated in FIG. 14 determines the deformation amount δ of the strain sensor 12 mounting portion from the displacement x of the tower 8 using the strain sensor 12. Assuming that the geometrical relationship shown in FIG. 13 is established, the strain sensor characteristic unit 142 determines the deformation amount δ by the following equation based on Equation 18.

≪Improved effect of tower vibration control by independent pitch control≫
In the second embodiment, as in the first embodiment, the effect of the tower vibration suppression control can be improved by independently adjusting the pitch angle of the plurality of blades 2 based on the rotational position of the rotor 4. The tower vibration suppression control based on the independent pitch angle command is the same as in the first embodiment, and a detailed description thereof is omitted.

<< Flowchart of tower vibration suppression control in embodiment 2 >>
FIG. 18 shows an example of a flowchart of tower vibration suppression control in the second embodiment. In step S1801, the deformation amount δ is determined based on the output signal of the strain sensor 12, and the process proceeds to the next step. In the following step S1802, the displacement speed vx of the vibration of the tower 8 is determined based on the deformation amount δ, and the process proceeds to the next step. In step S1803, the pitch angle command value θ ^* _c of each blade 2 is determined based on the displacement speed vx of the tower 8, and the process proceeds to the next step. In step S1804, based on the pitch angle command value theta ^* _c, to determine the independent pitch angle command value theta ^* _i, the series of processing is terminated.

The flowchart of the tower vibration suppression control in this embodiment is not limited to this, as in the first embodiment. For example, step S1804 for determining the independent pitch angle command value θ ^* _i is omitted, and steps S1801 to S1803 are omitted. Even if only the process is performed, the effect can be obtained.

  As an example of the vibration suppression control of the tower 8 by the independent pitch control described in the first and second embodiments, controlling the pitch angle according to the rotational position of each blade 2 also suppresses the vibration of the tower 8. It is effective as a means. For example, the absolute value of the deviation with respect to the pitch angle average value indicating the average value of the pitch angle in the vicinity of the rotational position where the blade 2 is highest from the position of the base of the tower 8 is the pitch angle average value of the pitch angles of other rotational positions. The pitch angle can be controlled by the pitch actuator 5 so as to be larger than the absolute value of the deviation with respect to. Thereby, when the blade 2 is at a high position, the thrust force adjusting effect is increased. For example, when the tower 8 is greatly inclined backward, the pitch angle is increased to release the wind, and the force pushed backward by the wind is reduced. When the tower is inclined largely forward, the pitch angle is decreased. The pitch angle can also be controlled so as to increase the force pushed backward by receiving wind.

  Also, the absolute value of the deviation from the pitch angle average value indicating the average value of the pitch angle in the vicinity of the rotational position where the blade 2 is lowest from the position of the base of the tower 8 is the pitch angle average value of the pitch angles of other rotational positions. The pitch angle can be controlled by the pitch actuator 5 so as to be larger than the absolute value of the deviation with respect to. Thereby, the influence when the blade 2 and the tower 8 overlap can be reduced. For example, in the downwind type, the force received by the blade 2 decreases at the position where the tower 8 and the blade 2 overlap each other, so that the amount of change in the pitch angle is made larger than that of the blades at other rotational positions. Moreover, although there is a possibility that the effect is less in the upwind type, there is a possibility that the same effect can be obtained not a little due to the influence of the turbulent flow (wake) caused by the tower 8.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Wind power generator, 2 ... Blade, 3 ... Hub, 4 ... Rotor, 5 ... Pitch actuator, 6 ... Nacelle, 7 ... Inclination angle sensor, 8 ... Tower, 9, 120 ... Controller, 12, 12a, 12b, 12c DESCRIPTION OF SYMBOLS ... Strain sensor 51, 141 ... Displacement speed calculating part 52 ... Displacement speed deviation calculating part 53 ... Pitch angle command value calculating part 54 ... Blade characteristic part 55, 102 ... Adder part 56 ... Tower vibration characteristic part, 57 ... Inclination angle sensor characteristic unit, 61, 151 ... Tower displacement calculation unit, 62, 152 ... Differentiation calculation unit, 71, 161 ... Noise removal processing unit, 81, 171 ... Band pass filter characteristic unit, 101 ... Independent pitch angle deviation Calculation unit, 142... Strain sensor characteristic unit, 501 and 1401. Tower vibration suppression control unit, 502 and 1402.

Claims (12)

A tower installed on the ground or offshore and serving as a support for the wind power generator;
A nacelle provided on the tower and provided with a generator inside;
A wind turbine generator provided at one end of the nacelle, comprising a rotor composed of a plurality of blades and a hub that receives wind and converts it into rotational energy,
An inclination angle detecting means for detecting the inclination of the nacelle;
Pitch angle control means provided on the blade for adjusting the pitch angle of the blade with respect to the hub, and
Based on the inclination angle of the nacelle detected by the inclination angle detection means, the pitch angle control means controls the pitch angle of the blade ,
The pitch angle control means is configured such that an absolute value of a deviation from an average pitch angle value indicating an average value of the pitch angle in the vicinity of the rotational position where the blade is highest from the position of the base of the tower is a pitch angle of another rotational position. The wind power generator characterized by controlling said pitch angle so that it may become larger than the absolute value of the deviation with respect to the average value of pitch angle . A tower installed on the ground or offshore and serving as a support for the wind power generator;
A nacelle provided on the tower and provided with a generator inside;
A wind turbine generator provided at one end of the nacelle, comprising a rotor composed of a plurality of blades and a hub that receives wind and converts it into rotational energy,
An inclination angle detecting means for detecting the inclination of the nacelle;
Pitch angle control means provided on the blade for adjusting the pitch angle of the blade with respect to the hub, and
Based on the inclination angle of the nacelle detected by the inclination angle detection means, the pitch angle control means controls the pitch angle of the blade ,
The pitch angle control means is configured such that an absolute value of a deviation from an average pitch angle value indicating an average value of the pitch angle in the vicinity of the rotational position where the blade is lowest from the position of the base of the tower is a pitch angle of another rotational position. The wind power generator characterized by controlling said pitch angle so that it may become larger than the absolute value of the deviation with respect to the average value of pitch angle . The wind power generator according to claim 1 or 2 , wherein the inclination angle detecting means is an inclination angle sensor installed in the nacelle. The wind power generator according to claim 1 or 2 , wherein the inclination angle detecting means is an inclination angle sensor installed in the tower. The pitch angle control means 4 based on the tilt angular velocity which is determined from the inclination angle of the nacelle detected by the inclination angle detecting means, from claim 1, wherein the controller controls the pitch angle of the blades The wind power generator of any one of these . The pitch angle control means controls the pitch angle of the blade based on a tower displacement indicating a tower deformation amount determined from the inclination angle of the nacelle detected by the inclination angle detection means. The wind power generator according to any one of claims 1 to 4 .   The pitch angle control means controls the pitch angle of the blade based on a tower displacement speed indicating the tower displacement speed determined from the inclination angle of the nacelle detected by the inclination angle detection means. The wind power generator according to claim 6, wherein A tower installed on the ground or offshore and serving as a support for the wind power generator;
A nacelle provided on the tower and provided with a generator inside;
A wind turbine generator provided at one end of the nacelle, comprising a rotor composed of a plurality of blades and a hub that receives wind and converts it into rotational energy,
A strain detecting means provided on the tower for detecting strain of the tower;
Pitch angle control means provided on the blade for adjusting the pitch angle of the blade with respect to the hub, and
Based on the distortion amount of the tower detected by the distortion detection means, the pitch angle control means controls the pitch angle of the blade ,
The pitch angle control means is configured such that an absolute value of a deviation from an average pitch angle value indicating an average value of the pitch angle in the vicinity of the rotational position where the blade is highest from the position of the base of the tower is a pitch angle of another rotational position. The wind power generator characterized by controlling said pitch angle so that it may become larger than the absolute value of the deviation with respect to the average value of pitch angle . A tower installed on the ground or offshore and serving as a support for the wind power generator;
A nacelle provided on the tower and provided with a generator inside;
A wind turbine generator provided at one end of the nacelle, comprising a rotor composed of a plurality of blades and a hub that receives wind and converts it into rotational energy,
A strain detecting means provided on the tower for detecting strain of the tower;
Pitch angle control means provided on the blade for adjusting the pitch angle of the blade with respect to the hub, and
Based on the distortion amount of the tower detected by the distortion detection means, the pitch angle control means controls the pitch angle of the blade ,
The pitch angle control means is configured such that an absolute value of a deviation from an average pitch angle value indicating an average value of the pitch angle in the vicinity of the rotational position where the blade is lowest from the position of the base of the tower is a pitch angle of another rotational position. The wind power generator characterized by controlling said pitch angle so that it may become larger than the absolute value of the deviation with respect to the average value of pitch angle . The pitch angle control means based on the tilt angular velocity of the nacelle which is determined from the amount of strain of the tower that has been detected by said strain detecting means, according to claim 8, wherein the controller controls the pitch angle of the blades Or the wind power generator according to 9 . 10. The pitch angle control unit according to claim 8 , wherein the pitch angle control unit controls the pitch angle of the blade based on a tower displacement indicating a distortion amount of the tower detected by the strain detection unit. Wind power generator. The pitch angle control means controls the pitch angle of the blade based on a tower displacement speed indicating a tower displacement speed indicating the distortion amount of the tower detected by the distortion detection means. The wind power generator according to claim 11 .

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