WO2023159369A1 - Wind turbine and vibration suppression method therefor - Google Patents

Abstract

A vibration suppression method for a wind turbine. The method comprises: first, determining an included angle between a wind direction and a rotor rotation axis of a wind turbine, and the positions of blades in a rotor rotation plane, then determining an optimized pitch angle of each blade according to the included angle between the wind direction and the rotor rotation axis of the wind turbine, and the positions of the blades in the rotor rotation plane, and driving each blade by means of a pitch system to reach the optimized pitch angle, thereby suppressing the vibrations of a tower and the blades of the wind turbine in a non-operating state.

Description

A kind of wind power generator and vibration suppression method thereof technical field

The invention relates to the technical field of wind power generation, in particular to a wind power generator and a vibration suppression method thereof.

Background technique

With the development of wind power generation technology, wind power generators are developing towards large-scale, and large-scale wind power generators of megawatt level have been put into use at present. For large wind turbines, as the diameter of the impeller and the height of the tower increase, the possibility of vibration of the fan blades and the tower increases gradually. For example, as the height of the tower increases, the frequency of the tower decreases gradually, and vortex induced resonance is prone to occur in the shutdown scenario, which seriously shortens the fatigue life of the tower.

At present, the vibration of wind turbines is mostly suppressed in the following ways: installing aerodynamic devices on the surface of the tower or blades, or installing dampers inside the tower or blades, or adjusting the angle difference between the two blades. Although the installation of aerodynamic devices on the surface of the tower or blades can effectively suppress the vibration of the tower or blades when the wind turbine is not in operation, the installation of the aerodynamic devices is complicated, and it needs to be removed when the wind turbine is running, and the process is complicated. Installing the damper inside the tower or the blade requires a certain amount of installation space, and the cost is relatively high. If the vibration is suppressed simply by the angle difference between the two blades, in some cases, it is difficult to completely suppress the blade vibration under the condition of the wind rotor being locked.

Contents of the invention

Aiming at some or all of the problems in the prior art, the present invention provides a vibration suppression method for wind power generators, including:

Determine the angle between the wind direction and the axis of rotation of the wind turbine rotor;

Determine the position of the blades in the plane of rotation of the rotor;

Determine the optimal pitch angle of each blade according to the angle between the wind direction and the rotor rotation axis of the wind power generator and the position of the blades in the rotor rotation plane; and

The blades are driven to the optimal pitch angle by a pitch system.

Further, the angle between the wind direction and the rotation axis of the wind rotor of the wind generator is obtained by measuring the wind vane, wherein the wind vane can be, but not limited to, installed above the nacelle of the wind generator.

Further, determining the angle between the wind direction and the rotation axis of the wind turbine rotor includes:

Measure absolute wind direction;

Measure the absolute orientation of the axis of rotation of the wind turbine rotor; and

Calculate the included angle between the absolute wind direction and the absolute direction of the rotation axis of the fan rotor.

Further, the absolute wind direction is the angle between the wind direction and the true north direction; and

The absolute direction of the rotation axis of the fan rotor is the angle between the rotation axis of the fan rotor and the true north direction.

Further, determining the position of the blade in the rotation plane of the wind rotor includes:

The azimuth angle of the blade is obtained by a sensor.

Further, determining the position of the blade in the rotation plane of the wind rotor includes:

Through manual observation, the azimuth angle of the blade is determined.

Further, determining the optimal pitch angle includes:

The optimal pitch angle is determined by a lookup table, wherein the lookup table is a two-dimensional optimal pitch angle based on the angle between the wind direction and the rotation axis of the wind turbine and the position of the blades in the rotation plane of the wind turbine sheet.

Further, determining the optimal pitch angle may also include:

The optimal pitch angle is determined by a calculation program, wherein the calculation program is based on the angle between the wind direction and the rotation axis of the wind turbine and the position of the blades in the rotation plane of the wind rotor to calculate the optimal pitch angle. program.

Further, the formation of the look-up table or calculation program includes:

The calculation software with fluid-solid coupling simulation function is used for simulation to determine the angle between different wind directions and the rotation axis of the wind turbine rotor, and the vibration amplitude corresponding to different pitch angles under the position of the blade in the rotation plane of the wind rotor. And record the pitch angle corresponding to the minimum vibration amplitude to form a lookup table or calculation program.

Further, the formation of the look-up table or calculation program includes:

Manually observe or install sensors on the blades and towers of the installed wind turbines;

Manually change the pitch angle through the pitch control system of the wind turbine, and measure the angle between different wind directions and the rotation axis of the wind rotor of the wind turbine through manual observation or the sensor, and the position of the blades in the rotation plane of the wind rotor. the amplitude of vibration corresponding to the angle of separation; and

The pitch angle corresponding to the minimum vibration amplitude in the combination of the angle between each wind direction and the rotor rotation axis of the wind turbine and the position of the blade in the rotor rotation plane is used as the optimal pitch angle to form a lookup table or calculation program.

Another aspect of the present invention provides a pitch system for a wind power generator, which includes:

a pitch drive system for pitching the blades in accordance with control command signals received by it; and

The controller is used to output the control command signal to the pitch according to the above-mentioned method when the wind turbine is in a non-operating state and the rotation axis of the wind rotor cannot be kept in line with the wind direction through the yaw system of the wind turbine. Drive System.

Another aspect of the present invention provides a wind power generator, which includes the aforementioned pitch control system.

The present invention is based on the following insights of the inventors: when the wind turbine is in a non-operating state and the yaw system cannot be used to keep the rotation axis of the wind rotor in line with the wind direction, under certain wind direction angles and blade position conditions, the airflow will When flowing through the blade or tower, there will be unstable flow phenomenon, showing unstable aerodynamic characteristics, resulting in unstable aerodynamic negative damping phenomenon, resulting in relatively large blade and tower vibration. The inventor found through research that the risk of vibration of the blades and the tower of the wind generator mainly depends on the aerodynamic characteristics of the blades. The aerodynamic properties of the blade are determined by the specific size of the angle of attack of the blade section. The inventor found through further research that the relative wind direction in the cross-sectional plane of the blade, combined with the pitch angle of the blade, jointly determines the angle of attack of the blade cross-section. Wherein, the relative wind direction of the incoming wind in the cross-section of the blade is jointly determined by the angle between the wind direction and the rotation axis of the fan rotor and the position of the blade in the rotor surface. Based on this, the inventor found that the optimal pitch angle of each blade can be determined according to the angle between the wind direction and the rotation axis of the wind turbine rotor and the position of the blades in the rotor surface, thereby obtaining an optimized angle of attack and optimized aerodynamics characteristics to achieve the purpose of reducing the risk of wind turbine blade and/or tower vibration. The present invention provides a wind power generator and its vibration suppression method. By adjusting the pitch angle of each blade respectively, the angle of attack of the blade section is improved, thereby improving the flow of the airflow through the blade. On the one hand, the blade itself can be avoided. Unstable aerodynamic characteristics, on the other hand, can increase the aerodynamic damping of the blade itself to suppress the vibration caused by the aerodynamic instability of the tower. The vibration suppression method can simultaneously suppress the vibration risks of the blades and the tower of the wind power generator under non-operating conditions, and covers a wider range. At the same time, it is implemented based on standard fan components without adding additional devices and costs. It has good versatility, convenient and reliable execution, and can be used as a long-term solution because it does not involve consumable parts.

Description of drawings

To further clarify the above and other advantages and features of various embodiments of the present invention, a more particular description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It is understood that the drawings depict only typical embodiments of the invention and therefore are not to be considered limiting of its scope. In the drawings, the same or corresponding parts will be denoted by the same or similar symbols for clarity.

Fig. 1 shows a schematic structural view of a wind power generator according to an embodiment of the present invention;

Fig. 2 shows a schematic diagram of the angle between the rotation axis of the wind rotor and the wind direction of a wind generator according to an embodiment of the present invention;

Fig. 3 shows a schematic diagram of a pitch angle of a wind generator according to an embodiment of the present invention;

Figure 4 shows a schematic diagram of the angle of attack of a blade section of a wind generator according to an embodiment of the present invention; and

Fig. 5 shows a schematic flowchart of a vibration suppression method for a wind power generator according to an embodiment of the present invention.

Detailed ways

In the following description, the present invention is described with reference to various examples. One skilled in the art will recognize, however, that the various embodiments may be practiced without one or more of the specific details, or with other alternative and/or additional methods, materials, or components. In other instances, well-known structures, materials, or operations are not shown or described in detail so as not to obscure the inventive concepts of the present invention. Similarly, for purposes of explanation, specific quantities, materials and configurations are set forth in order to provide a thorough understanding of embodiments of the invention. However, the invention is not limited to these specific details. Furthermore, it should be understood that the embodiments shown in the drawings are illustrative representations and are not necessarily drawn to correct scale.

In this specification, reference to "one embodiment" or "the embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. The appearances of the phrase "in one embodiment" in various places in this specification are not necessarily all referring to the same embodiment.

It should be noted that the embodiments of the present invention describe the method steps in a specific order, but this is only for illustrating the specific embodiment, rather than limiting the sequence of the steps. On the contrary, in different embodiments of the present invention, the order of each step can be adjusted according to the adjustment of actual needs.

For wind turbines, in the case of certain wind direction angles and blade positions, the airflow flowing through the blades or towers will appear unstable flow phenomenon, showing unstable aerodynamic characteristics, resulting in unstable aerodynamics. Negative damping phenomenon, resulting in relatively large blade and tower vibration. During the operation of the wind turbine, the direction of the wind rotor can be adjusted through the yaw system to keep the rotation axis of the wind rotor in line with the wind direction, thereby avoiding the risk of vibration. However, when the wind turbine is in a hoisting state, or the yaw system fails, so that the wind turbine is in a non-operating state, this vibration needs to be suppressed by other means. For example, installing pneumatic devices or dampers, etc. However, additionally installing corresponding devices or setting procedures is complicated, and labor and material costs are relatively high. In order to achieve simpler and more effective vibration suppression, it is first necessary to determine the relevant factors that affect vibration risk. The inventor found through research that the risk of vibration of the blades and the tower of the wind generator mainly depends on the aerodynamic characteristics of the blades. The aerodynamic properties of the blade are determined by the specific size of the angle of attack of the blade section. Fig. 4 shows a schematic diagram of an angle of attack of a section of a blade of a wind power generator according to an embodiment of the present invention. As shown in FIG. 4 , the angle of attack of the blade section is equal to the difference between the relative wind direction of the incoming wind in the section plane of the blade and the pitch angle of the blade. Fig. 3 shows a schematic diagram of a pitch angle of a wind generator according to an embodiment of the present invention. As shown in Figure 3, the pitch angle refers to the angle between the blades of the wind turbine and the impeller rotation plane. Generally, the angle between the airfoil chord line near the top of the blade and the impeller rotation plane is selected as the pitch angle. The relative wind direction of the incoming wind in the cross-section of the blade is determined by the angle between the wind direction and the rotation axis of the fan rotor and the position of the blade in the rotor surface. Fig. 1 and Fig. 2 respectively show the position of the blade of a kind of wind power generator in an embodiment of the present invention in the surface of the wind rotor, and the schematic diagram of the included angle between the rotation axis of the wind rotor and the wind direction. As shown in Fig. 1, the blade The position within the wind rotor plane refers to the azimuth angle of the blade, that is, the angle between the axis of the blade and the axis of the wind turbine tower.

Based on this, the inventor provides a vibration suppression method for wind power generators, which improves the angle of attack of the blade section by adjusting the pitch angle of the blade, thereby improving the flow of the airflow through the blade, on the one hand, it can avoid the blade itself. To stabilize the aerodynamic characteristics, on the other hand, the aerodynamic damping of the blade itself can be increased to suppress the vibration caused by the aerodynamic instability of the tower.

The solutions of the present invention will be further described below in conjunction with the accompanying drawings of the embodiments.

Fig. 5 shows a schematic flowchart of a vibration suppression method for a wind power generator according to an embodiment of the present invention. As shown in Figure 5, a vibration suppression method for wind power generators, including:

First, in step 501, the angle between the wind direction and the rotation axis of the wind rotor of the wind generator is determined. The included angle between the wind direction and the rotation axis of the wind rotor of the wind generator can be directly or indirectly measured by a corresponding measuring device. In one embodiment of the present invention, determining the included angle between the wind direction and the rotation axis of the wind rotor of the wind generator includes: installing a wind vane above the nacelle of the wind generator, and then directly measuring the angle between the wind direction and the wind generator through the wind vane. The included angle of the axis of rotation of the wind rotor. In an embodiment of the present invention, determining the angle between the wind direction and the rotation axis of the wind turbine rotor includes: measuring the absolute wind direction and the absolute direction of the rotation axis of the wind turbine rotor, and then subtracting the two to calculate The angle between the absolute wind direction and the absolute direction of the rotation axis of the fan rotor, wherein the absolute wind direction refers to the angle between the wind direction and a specified direction, and the absolute direction of the rotation axis of the fan rotor refers to the The angle between the axis of rotation of the fan rotor and the specified direction. It should be understood that, in other embodiments of the present invention, other devices or sensors may also be used to measure the wind vane to obtain the angle between the wind direction and the rotation axis of the wind turbine rotor, and/or the absolute wind direction;

Next, at step 502, the position of the blade in the rotation plane of the rotor is determined. In an embodiment of the present invention, the position of the blade in the rotation plane of the wind rotor refers to the azimuth angle of the blade, that is, the angle between the axis of the blade and the axis of the wind turbine tower. The position of the blades in the plane of rotation of the rotor can be determined by measurement or observation. In one embodiment of the present invention, the azimuth information of the blades is obtained through sensors, and in another embodiment of the present invention, the azimuth information of the blades is obtained through manual observation. In an embodiment of the present invention, the measurement error of the azimuth angle of the blade should not be higher than 30 degrees.

Next, in step 503, an optimal pitch angle is determined. According to the included angle between the wind direction and the rotor rotation axis of the wind power generator and the position of the blades in the rotor rotation plane, the optimal pitch angle of each blade can be further determined. Wherein, the optimized pitch angle refers to the blade that minimizes the vibration amplitude of the blade and/or the tower under the angle between the current wind direction and the rotation axis of the wind turbine and the position of the blade in the rotation plane of the wind turbine. distance angle. In the embodiment of the present invention, under all combinations of different wind directions and the angle between the wind turbine rotor axis of rotation and the position of the blades in the plane of the rotor, there are at least two groups of combinations, each corresponding to the difference in the optimal pitch angle at least 5°. The optimal pitch angle can be determined by means of a calculation program or a lookup table, for example. Specifically, under the premise of knowing the angle between the wind direction and the rotor rotation axis of the wind turbine, the position of the blades in the rotor rotation plane, and the pitch angle, the blade and/or tower angle can be calculated by simulation software. Vibration amplitude of the drum. For example, in one embodiment of the present invention, the aerodynamic force generated by the airflow passing through the blade and the structural response of the blade and the tower to the aerodynamic force are coupled and solved in the time domain through the calculation software with fluid-structure coupling simulation function, Obtain blade and/or tower vibration amplitudes under different operating conditions. Therefore, in one embodiment of the present invention, after determining the angle between the wind direction and the rotor rotation axis of the wind turbine and the position of the blades in the rotor rotation plane, the different pitch angles can be calculated by simulation software. The vibration amplitude of the lower blade and/or tower, and then the pitch angle corresponding to the minimum vibration amplitude is used as the optimal pitch angle. In one embodiment of the present invention, an optimized pitch angle two-dimensional table or calculation program based on the angle between the wind direction and the rotation axis of the wind turbine and the position of the blades in the rotation plane of the wind turbine is formed in advance , and then, after determining the angle between the wind direction and the rotor rotation axis of the wind turbine and the position of the blades in the rotor rotation plane, the optimal pitch angle is determined by looking up a table or calling a calculation program. In one embodiment of the present invention, in the look-up table, there are at least two combinations of angles and positions in the full range of angles between the wind direction and the rotation axis of the fan rotor and all positions of the blades in the plane of the rotor , the difference in the optimal pitch angles corresponding to the two combinations is at least 5°. The look-up table or calculation program can be obtained by, but not limited to, simulation or actual testing. In one embodiment of the present invention, the various working conditions of the wind turbine in the non-operating state are simulated by using the calculation software with fluid-structure coupling simulation function, wherein the definition of the working conditions needs to cover all possible Different combinations of the angle between the wind direction and the rotation axis of the rotor of the wind turbine, the position of the blades in the rotation plane of the rotor, and the pitch angle of the blades. And the structural response of the blade and the tower to the aerodynamic force is coupled to solve, and then the minimum vibration amplitude of the blade under different working conditions is obtained, so as to obtain the optimized pitch angle. In yet another embodiment of the present invention, the vibration amplitude of the blades under different working conditions is actually measured by means of sensors and other devices. Sensors or strain gauges and other sensors, and manually change the pitch angle through the pitch system of the wind turbine, and then obtain and record the angle between different wind directions and the rotation axis of the wind turbine’s rotor through the sensor or manual observation. , the position of the blade in the rotation plane of the wind rotor and the vibration amplitude of the blade and/or tower at different pitch angles, determine the pitch angle with the smallest vibration amplitude of the blade and/or tower, that is, the optimal pitch angle, compared with In terms of simulation, due to the huge number of combinations of different working conditions, the actual test requires a longer test period. It should be understood that in other embodiments of the present invention, other methods can also be used to determine the optimal Pitch angle, for example, the optimal pitch angle can be determined according to historical experience values, for example:

When the angle between the wind direction and the axis of rotation of the wind rotor of the wind power generator is 0 degrees, and the position of the blade in the wind rotor surface is vertically upward (0 degrees), the optimal pitch angle of the blade is 90 degrees;

When the angle between the wind direction and the axis of rotation of the wind rotor of the wind turbine is 90 degrees, and the position of the blade in the rotor surface is vertical (0 degrees), the optimal pitch angle of the blade is 0 degrees; and

When the included angle between the wind direction and the axis of rotation of the rotor of the wind turbine is 90 degrees, and the position of the blade in the rotor surface is horizontal (90 degrees), the optimal pitch angle of the blade is 90 degrees; and

Finally, at step 504, the blades are driven to an optimal pitch angle. After the optimal pitch angle is determined, each blade is driven to the optimal pitch angle through the pitch control system of the wind turbine, for example, the controller can be used to automatically drive the blades to the optimal pitch angle through the pitch control system; Manually operate and observe, manually drive the blades through the pitch system to reach the optimal pitch angle.

Another aspect of the present invention provides a wind power generator, which includes a pitch control system, and the pitch control system includes a pitch drive system and a controller. Wherein, the pitch drive system is used to change the pitch of the blades according to the control command signal it receives, and the controller is in a non-running state, such as a hoisting state, or when the wind turbine is in a state of yaw system failure, etc., Through the vibration suppression method as mentioned above, according to the angle between the wind direction and the rotation axis of the wind turbine rotor and the position of the blades in the rotor surface, the control command signal is output to the pitch drive system to adjust the respective blades to reach the corresponding optimal pitch angle , and then improve the angle of attack of the blade section and improve the flow of the airflow through the blade. On the one hand, it can avoid the unstable aerodynamic characteristics of the blade itself, and on the other hand, it can increase the aerodynamic damping of the blade itself to suppress the aerodynamic instability zone of the tower. coming vibration.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to those skilled in the relevant art that various combinations, modifications and changes can be made thereto without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention disclosed herein should not be limited by the above-disclosed exemplary embodiments, but should be defined only in accordance with the appended claims and their equivalents.

Claims (12)

A vibration suppression method for wind power generators, comprising the steps of: Determining the angle between the wind direction and the axis of rotation of the rotor of the wind turbine; Determine the position of the blades in the plane of rotation of the rotor; determining an optimal pitch angle for each blade according to the included angle and the position; and The blades are pitched according to the optimized pitch angle. The vibration suppression method according to claim 1, characterized in that, within the entire range of the included angle and the entire range of the position, there are at least two sets of combinations of included angles and positions, each corresponding to the optimized The difference in pitch angle is not less than 5°. The vibration suppression method according to claim 1, wherein determining the angle between the wind direction and the rotation axis of the wind rotor of the wind turbine comprises: The included angle between the wind direction and the rotation axis of the wind rotor of the wind generator is measured by a wind vane, wherein the wind vane is located above the nacelle of the wind generator. The vibration suppression method according to claim 1, wherein determining the angle between the wind direction and the rotation axis of the wind rotor of the wind turbine comprises: Measure or manually observe the absolute wind direction; Measure or manually observe the absolute orientation of the axis of rotation of the wind turbine rotor; and Calculate the included angle between the absolute wind direction and the absolute direction of the rotation axis of the fan rotor. The vibration suppression method according to claim 4, wherein the absolute wind direction is the angle between the wind direction and a specified absolute direction; and The absolute direction of the rotation axis of the fan rotor is the angle between the rotation axis of the fan rotor and a specified absolute direction. The vibration suppression method according to claim 1, wherein determining the position of the blade in the rotation plane of the wind rotor comprises: The azimuth angle of the blade is acquired by a sensor. The vibration suppression method according to claim 1, wherein determining the position of the blade in the rotation plane of the wind rotor comprises: Through manual observation, the azimuth angle of the blade is determined. The vibration suppression method according to claim 1, wherein determining the optimal pitch angle comprises: The optimal pitch angle is determined by a lookup table or a calculation program, wherein the lookup table or calculation program is based on the angle between the wind direction and the rotation axis of the rotor of the wind turbine and the position of the blades in the rotation plane of the rotor Optimize the pitch angle two-dimensional table or calculation program. The vibration suppression method according to claim 8, wherein the formation of the look-up table or calculation program comprises: The calculation software with fluid-solid coupling simulation function is used for simulation to determine the angle between different wind directions and the rotation axis of the wind turbine rotor, and the vibration amplitude corresponding to different pitch angles under the position of the blade in the rotation plane of the wind rotor. And record the pitch angle corresponding to the minimum vibration amplitude to form a lookup table or calculation program. The vibration suppression method according to claim 8, wherein the formation of the look-up table or calculation program comprises: Manual observation of installed wind turbines or installation of sensors on blades and towers; Manually change the pitch angle through the pitch control system of the wind turbine, and measure the angle between different wind directions and the rotation axis of the wind rotor of the wind turbine through manual observation or the sensor, and the position of the blades in the rotation plane of the wind rotor. the amplitude of vibration corresponding to the angle of separation; and The pitch angle corresponding to the minimum vibration amplitude in the combination of the angle between each wind direction and the rotor rotation axis of the wind turbine and the position of the blade in the rotor rotation plane is used as the optimal pitch angle to form a lookup table or calculation program. A pitch system for a wind generator, characterized in that it comprises: a pitch drive system configured to pitch the blades in accordance with control command signals received therefrom; and A controller configured to execute the method according to any one of claims 1 to 10 when the wind turbine is in a non-operating state and cannot align its rotor rotation axis with the wind direction through the wind turbine yaw system Output the control command signal to the pitch drive system. A wind power generator, characterized by comprising the pitch control system according to claim 11.

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