CN111946547B

CN111946547B - Method, device and system for adjusting pitch angle of blade of wind generating set

Info

Publication number: CN111946547B
Application number: CN201910401204.9A
Authority: CN
Inventors: 邢波; 赵亮; 肖明明
Original assignee: Xinjiang Goldwind Science and Technology Co Ltd
Current assignee: Jinfeng Technology Co ltd
Priority date: 2019-05-15
Filing date: 2019-05-15
Publication date: 2022-08-30
Anticipated expiration: 2039-05-15
Also published as: CN111946547A

Abstract

A method, apparatus and system are provided for adjusting a pitch angle of a blade of a wind park, the method comprising: acquiring wind speed data and vibration data of a wind generating set in real time; analyzing the acquired wind speed data and the vibration data to obtain a wind speed value and a vibration value; determining whether the wind speed value is greater than or equal to a predetermined wind speed value and determining whether the oscillation value is greater than or equal to a predetermined oscillation value; when the wind speed value is larger than or equal to the preset wind speed value and the vibration value is larger than or equal to the preset vibration value, adjusting the pitch angle of the blades in the target wind sweeping area in the wind generating set according to the stress condition of the wind sweeping surface of the impeller of the wind generating set. According to the method, the device and the system, the problem of abnormal vibration of the wind generating set caused by unbalanced stress of the wind sweeping surface of the impeller in the wind generating set in the prior art can be solved by adjusting the pitch angle of the blades in the target wind sweeping area.

Description

Method, device and system for adjusting pitch angle of blade of wind generating set

Technical Field

The present invention relates generally to the field of wind power plant control, and more particularly to a method, apparatus and system for adjusting a pitch angle of a blade of a wind turbine generator set.

Background

The wind generating set is equipment for converting collected wind energy into electric energy. As shown in fig. 1, the wind turbine includes a blade 1, a hub 2, a nacelle 3, a wind measuring system 4, and a tower 5. Generally, when the wind F blows in a direction perpendicular to the wind generating set, the wind speeds of the wind farm at different heights are ideally the same, in which case the forces on the windswept surfaces of the blades of the wind generating set are balanced, so that the availability of the devices of the wind generating set is high.

However, in complex mountains with undulating terrain, wind generating sets are typically deployed on the ridges, typically with the primary wind direction perpendicular to the ridges, which is a condition that makes negative shear of wind speed over the complex terrain possible. Referring to fig. 2A and 2B, in particular, the abscissa in fig. 2A and 2B represents the wind speed, the ordinate represents the altitude, the line segment with an arrow in fig. 2A and 2B indicates a wind speed vector, the arrow indicates a direction of a wind speed, the length of the line segment indicates a magnitude of the wind speed, and in particular, the distribution of wind speed in the vertical direction is typically logarithmic due to the influence of ground friction, for example, as shown by the logarithmic distribution curve of wind speed in figure 2A, however, when encountering a steep slope under neutral atmospheric conditions, the distribution of wind speed no longer follows a logarithmic distribution, but is more uniform and even, under steady atmospheric conditions, wind on top of a hill may experience negative shear conditions, for example, where wind speed is high at low altitudes and low at high altitudes, as shown by the negative shear curve of wind speed in FIG. 2B. When negative shearing occurs to wind speed, the inflow angle of the wind generating set is too large, and the main shaft of the wind generating set bears abnormal unbalanced load due to the too large inflow angle, so that the bearing, the gear box and the elastic support are damaged.

In addition, there are special cases where there are hill bags and the like in front of the wind turbine generators deployed in individual wind farms. For example, as shown in fig. 3, a wind turbine generator deployed behind a hill bag is disturbed by airflow separation in the main wind direction due to the position limitation, and a fault of abnormal vibration often occurs, which seriously affects the availability of the wind turbine generator.

Disclosure of Invention

An exemplary embodiment of the present invention is to provide a method, an apparatus, and a system for adjusting a pitch angle of a blade of a wind turbine generator system, which are used to solve the problem of abnormal vibration of the wind turbine generator system caused by unbalanced stress on a windward side of an impeller in the prior art.

According to an aspect of an exemplary embodiment of the present invention, there is provided a method of adjusting a pitch angle of a blade of a wind park, comprising: acquiring wind speed data and vibration data of a wind generating set in real time; analyzing the acquired wind speed data and vibration data to obtain a wind speed value and a vibration value; determining whether the wind speed value is greater than or equal to a predetermined wind speed value and determining whether the oscillation value is greater than or equal to a predetermined oscillation value; when the wind speed value is greater than or equal to the preset wind speed value and the vibration value is greater than or equal to the preset vibration value, adjusting the pitch angle of a blade in a target wind sweeping area in the wind generating set according to the stress condition of the wind sweeping surface of an impeller of the wind generating set, wherein when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind generating set is greater than the wind power received by the lower side, the target wind sweeping area refers to a semicircular plane area swept by the blade rotating from 0 degrees to 180 degrees horizontally when the blade rotates clockwise, or the semicircular plane area swept by the blade rotating from 180 degrees to 0 degrees horizontally when the blade rotates anticlockwise; when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side of the wind sweeping surface, the target wind sweeping area refers to a semicircular plane area swept by the blade rotating from 180 degrees to 0 degrees from the horizontal when the blade rotates clockwise, or the semicircular plane area swept by the blade rotating from 0 degrees to 180 degrees from the horizontal when the blade rotates anticlockwise.

Optionally, the step of adjusting the pitch angle of the blades in the wind generating set in the target wind sweeping area according to the stress condition of the wind sweeping surface of the impeller of the wind generating set comprises: determining whether the stress condition of the wind sweeping surface of an impeller of the wind generating set is obtained or not, and when the stress condition of the wind sweeping surface of the impeller of the wind generating set is obtained, adjusting the pitch angle of blades in a target wind sweeping area in the wind generating set according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set; when the stress condition of the wind-sweeping surface of the impeller of the wind generating set is not acquired, determining the stress condition of the wind-sweeping surface of the impeller of the wind generating set by using a first blade retracting angle, and adjusting the pitch angle of the blade in the target wind-sweeping area in the wind generating set according to the determined stress condition of the wind-sweeping surface of the impeller of the wind generating set.

Optionally, the step of determining the stress condition of the windward side of the impeller of the wind turbine generator system by using the first feathering angle includes: controlling the pitch angle of the blade turning from the first position to the second position to recover the first pitch angle at the first pitch-withdrawing speed, and then controlling the pitch angle of the blade turning from the second position to the third position to recover the first pitch angle at the first pitch-withdrawing speed; comparing the current first vibration value of the wind generating set with a second vibration value before the blades are controlled to retract to the first blade retracting angle; when the first vibration value is smaller than the second vibration value, determining that the wind force received by the upper side of the windsweeping surface of the impeller of the wind generating set is larger than the wind force received by the lower side; when the first vibration value is larger than the second vibration value, determining that the wind power received by the upper side of the windsweeping surface of the impeller of the wind power generator set is smaller than the wind power received by the lower side; and when the first vibration value is equal to the second vibration value, sending alarm information.

Optionally, the step of adjusting the pitch angle of the blades in the wind generating set in the target wind sweeping area according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set comprises: and adjusting the pitch angle of the blades in the target wind sweeping area in the wind generating set by using a second pitch-retracting angle according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set.

Optionally, the step of adjusting the pitch angle of the blades in the wind generating set in the target wind sweeping area by using the second feathering angle according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set comprises: when the wind power received by the upper side of the windsweeper of the impeller of the wind generating set is larger than the wind power received by the lower side of the windsweeper, the pitch angle of the blade turning from the first position to the second position is controlled to be retracted to a second blade retracting angle at a second blade retracting speed, and then the pitch angle of the blade turning from the second position to the third position is controlled to be retracted to the second blade retracting angle at the second blade retracting speed; when the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side of the windsweeping surface of the impeller of the wind generating set, controlling the pitch angle of the blade turned to the fourth position from the third position to be retracted to a second blade retracting angle at a second blade retracting speed, and then controlling the pitch angle of the blade turned to the first position from the fourth position to be retracted to the second blade retracting angle at the second blade retracting speed, wherein the first position indicates the position of the blade of the wind generating set when the blade is in the horizontal state when the blade is turned from bottom to top; the second position indicates the position when the blade of the wind generating set is vertical when rotating from top to bottom; the third position indicates the position when the blades of the wind generating set rotate from top to bottom and are in the horizontal state; the fourth position indicates the position when the blade of the wind generating set is vertical when rotating from bottom to top.

Optionally, the step of adjusting the pitch angle of the blades in the wind generating set in the target wind sweeping area according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set further comprises: after adjusting the pitch angle of the blades of the wind generating set in the target wind sweeping area by using the second pitch-retracting angle, comparing the current vibration value of the wind generating set with the preset vibration value; if the current vibration value is larger than or equal to the preset vibration value, controlling the pitch angle of the blade turned from the first position to the second position to recover a third pitch angle at a third pitch recovery speed under the condition that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is larger than the wind power received by the lower side, and then controlling the pitch angle of the blade turned from the second position to the third position to recover the third pitch angle at the third pitch recovery speed; and under the condition that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side of the windsweeping surface, controlling the pitch angle of the blade turned to the fourth position from the third position to be retracted to a third feathering angle at a third feathering speed, and then controlling the pitch angle of the blade turned to the first position from the fourth position to be retracted to the third feathering angle at the third feathering speed.

Optionally, the first feathering speed is determined based on a time required for an impeller of the wind turbine generator set to rotate ninety degrees and a first feathering angle; the second feathering speed is determined based on the time required for the impeller of the wind generating set to rotate ninety degrees and a second feathering angle; the third feathering speed is determined based on the time required for the impeller of the wind generating set to rotate ninety degrees and a third feathering angle; the first oar-retracting angle is smaller than the second oar-retracting angle, and the second oar-retracting angle is smaller than the third oar-retracting angle.

According to an aspect of an exemplary embodiment of the present invention, there is provided an apparatus for adjusting a pitch angle of a blade of a wind turbine generator system, comprising: the acquisition module is used for acquiring wind speed data and vibration data of the wind generating set in real time; the analysis module is used for analyzing the acquired wind speed data and vibration data to obtain a wind speed value and a vibration value; a determination module that determines whether the wind speed value is greater than or equal to a predetermined wind speed value and determines whether the oscillation value is greater than or equal to a predetermined oscillation value; the adjusting module is used for adjusting the pitch angle of the blade in a target wind sweeping area in the wind power generation set according to the stress condition of the wind sweeping surface of the impeller of the wind power generation set when the wind speed value is larger than or equal to the preset wind speed value and the vibration value is larger than or equal to the preset vibration value, wherein when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind power generation set is larger than the wind power received by the lower side, the target wind sweeping area refers to a semicircular plane area swept from 0 degrees to 180 degrees when the blade rotates clockwise, or a semicircular plane area swept from 180 degrees to 0 degrees when the blade rotates anticlockwise; when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side of the wind sweeping surface, the target wind sweeping area refers to a semicircular plane area swept by the blade rotating from 180 degrees to 0 degrees from the horizontal when the blade rotates clockwise, or the semicircular plane area swept by the blade rotating from 0 degrees to 180 degrees from the horizontal when the blade rotates anticlockwise.

Optionally, the adjusting module determines whether the stress condition of the wind-sweeping surface of the impeller of the wind generating set is obtained, and when the stress condition of the wind-sweeping surface of the impeller of the wind generating set is obtained, the adjusting module adjusts the pitch angle of the blades in the target wind-sweeping area in the wind generating set according to the determined stress condition of the wind-sweeping surface of the impeller of the wind generating set; when the stress condition of the wind-sweeping surface of the impeller of the wind generating set is not acquired, the adjusting module determines the stress condition of the wind-sweeping surface of the impeller of the wind generating set by using the first pitch angle, and adjusts the pitch angle of the blade in the target wind-sweeping area in the wind generating set according to the determined stress condition of the wind-sweeping surface of the impeller of the wind generating set.

Optionally, the apparatus further comprises: a sending module, wherein the adjusting module controls the pitch angle of the blade turning from the first position to the second position to withdraw a first pitch angle at a first pitch withdrawing speed, and then controls the pitch angle of the blade turning from the second position to the third position to recover the first pitch angle at the first pitch withdrawing speed, the adjusting module compares a current first vibration value of the wind generating set with a second vibration value before the blade is controlled to withdraw the first pitch angle, when the first vibration value is smaller than the second vibration value, the adjusting module determines that the wind power received by the upper side of the windswept surface of the impeller of the wind generating set is larger than the wind power received by the lower side, when the first vibration value is larger than the second vibration value, the adjusting module determines that the wind power received by the upper side of the windswept surface of the impeller of the wind generating set is smaller than the wind power received by the lower side, and when the first vibration value is equal to the second vibration value, and the sending module sends alarm information.

Optionally, the adjusting module adjusts a pitch angle of a blade in the wind generating set in the target wind sweeping area by using a second pitch-adjusting angle according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set.

Optionally, when the wind power received by the upper side of the windward side of the impeller of the wind generating set is greater than the wind power received by the lower side of the windward side of the impeller of the wind generating set, the adjusting module controls the pitch angle of the blade turning from the first position to the second position to be retracted to the second pitch retracting angle at the second pitch retracting speed, and then controls the pitch angle of the blade turning from the second position to the third position to be retracted to the second pitch retracting angle at the second pitch retracting speed; when the wind power received by the upper side of the wind-sweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side of the wind-sweeping surface of the impeller of the wind generating set, the adjusting module controls the pitch angle of the blade turning from the third position to the fourth position to retract to a second pitch angle at a second pitch-retracting speed, and then controls the pitch angle of the blade turning from the fourth position to the first position to recover to the second pitch-retracting angle at the second pitch-retracting speed, wherein the first position indicates the position of the blade of the wind generating set when the blade is in the horizontal state when the blade is rotated from bottom to top; the second position indicates the position of the blade of the wind generating set when the blade rotates from top to bottom and is in a vertical state; the third position indicates the position of the blade of the wind generating set when the blade rotates from top to bottom and is horizontal; and the fourth position indicates the position of the blade of the wind generating set when the blade rotates from bottom to top and is vertical.

Optionally, after adjusting the pitch angle of the blades of the wind turbine generator set in the target wind sweeping area by using the second feather angle, the adjusting module further compares the current vibration value of the wind turbine generator set with the predetermined vibration value, if the current vibration value is greater than or equal to the predetermined vibration value, the adjusting module controls the pitch angle of the blades turning from the first position to the second position to retract to a third feather angle at a third feather speed if the wind force received on the upper side of the wind sweeping surface of the impeller of the wind turbine generator set is greater than the wind force received on the lower side, and controls the pitch angle of the blades turning from the second position to the third position to return to the third feather angle at the third feather speed if the wind force received on the upper side of the wind sweeping surface of the impeller of the wind turbine generator set is less than the wind force received on the lower side, the adjusting module controls the pitch angle of the blade turning from the third position to the fourth position to retract to a third pitch angle at a third pitch-retracting speed, and then controls the pitch angle of the blade turning from the fourth position to the first position to recover to the third pitch-retracting angle at the third pitch-retracting speed.

Optionally, the first feathering speed is determined based on a time required for an impeller of the wind turbine generator set to rotate ninety degrees and a first feathering angle; the second feathering speed is determined based on time required for an impeller of the wind generating set to rotate ninety degrees and a second feathering angle; the third is received oar speed and is confirmed based on required time of ninety degrees of the impeller rotation of wind generating set and third receipts oar angle, wherein, first receipts oar angle is less than the second is received the oar angle, just the second is received the oar angle and is less than the third is received the oar angle.

According to another aspect of an exemplary embodiment of the present invention, there is provided a system for adjusting a pitch angle of a blade of a wind turbine generator system, comprising: a comparator; a wind speed sensor; a vibration detection device; at least one pitch system actuator; and a controller configured to: controlling the wind speed sensor to acquire wind speed data of the wind generating set in real time; controlling the vibration detection device to acquire vibration data of the wind generating set in real time; analyzing the acquired wind speed data and vibration data to obtain a wind speed value and a vibration value; controlling the comparator to determine whether the wind speed value is greater than or equal to a predetermined wind speed value and to determine whether the oscillation value is greater than or equal to a predetermined oscillation value; when the wind speed value is greater than or equal to the preset wind speed value, and the vibration value is greater than or equal to the preset vibration value, controlling the at least one pitch system actuator to adjust the pitch angle of the blade in a target wind sweeping area in the wind generating set according to the stress condition of the wind sweeping surface of the impeller of the wind generating set, wherein when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind generating set is greater than the wind power received by the lower side, the target wind sweeping area refers to a semicircular plane area swept by the blade from 0 degree to 180 degrees horizontally during clockwise rotation, or a semicircular plane area swept by the blade from 180 degrees to 0 degree horizontally during counterclockwise rotation; when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side of the wind sweeping surface, the target wind sweeping area refers to a semicircular plane area swept by the blade rotating from 180 degrees to 0 degrees from the horizontal direction when the blade rotates clockwise, or the semicircular plane area swept by the blade rotating from 0 degrees to 180 degrees from the horizontal direction when the blade rotates anticlockwise.

According to another aspect of exemplary embodiments of the present invention, a computer-readable storage medium is provided, having stored thereon a computer program, which, when being executed by a controller, carries out the method of adjusting a pitch angle of a blade of a wind park as described above.

According to the method, the device and the system for adjusting the pitch angle of the blade of the wind generating set, the problem of abnormal vibration of the wind generating set caused by unbalanced stress of the wind sweeping surface of the impeller in the prior art can be solved by adjusting the pitch angle of the blade in the target wind sweeping area.

Drawings

The above and other objects and features of exemplary embodiments of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings which illustrate exemplary embodiments, wherein:

FIG. 1 shows an ideal power generation state diagram of a wind turbine generator set;

FIGS. 2A and 2B illustrate examples of wind speed conditions for complex terrain;

FIG. 3 is a schematic view of a terrain with a hill in front of a wind turbine generator system;

FIG. 4 shows a flow chart of a method of adjusting a pitch angle of a blade of a wind park according to an exemplary embodiment of the invention;

FIGS. 5A and 5B illustrate examples of target windswept areas according to exemplary embodiments of the invention;

FIG. 6 illustrates an example of blade rotation according to an exemplary embodiment of the present invention;

FIG. 7 shows a block diagram of an apparatus for adjusting a pitch angle of a blade of a wind park according to an exemplary embodiment of the invention;

FIG. 8 shows a block diagram of a system for adjusting a pitch angle of a blade of a wind park according to an exemplary embodiment of the invention.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

FIG. 4 shows a flow chart of a method of adjusting a pitch angle of a blade of a wind park according to an exemplary embodiment of the invention. Here, the method may be implemented by an apparatus or system for adjusting the pitch angle of a blade of a wind park as an example, but may also be implemented entirely by a computer program.

As shown in fig. 4, in step S100, wind speed data and vibration data of the wind turbine generator system are acquired in real time. Here, as an example, the vibration data of the wind park refers to vibration data of a nacelle of the wind park.

In step S200, the acquired wind speed data and vibration data are parsed to obtain a wind speed value and a vibration value.

In step S300, it is determined whether the wind speed value is greater than or equal to a predetermined wind speed value, and it is determined whether the oscillation value is greater than or equal to a predetermined oscillation value.

When the wind speed value is greater than or equal to the predetermined wind speed value and the vibration value is greater than or equal to the predetermined vibration value, it means that the windward side of the impeller of the wind turbine generator set is unbalanced in force, and the unbalance causes abnormal vibration of the wind turbine generator set, in which case, in step S400, the pitch angle of the blade in the target windward region in the wind turbine generator set is adjusted according to the stress condition of the windward side of the impeller of the wind turbine generator set, so as to correct the wind force received by the blade of the wind turbine generator set, thereby reducing the occurrence of dangerous phenomena caused by the unbalanced stress of the windward side of the impeller of the wind turbine generator set.

Here, when the upper side of the windswept surface of the impeller of the wind turbine generator set receives a wind force larger than the lower side, the target windswept area refers to a semicircular plane area swept from 0 degrees horizontal to 180 degrees horizontal when the blade rotates clockwise or a semicircular plane area swept from 180 degrees horizontal to 0 degrees horizontal when the blade rotates counterclockwise (as shown by hatching in fig. 5A);

when the upper side of the wind sweeping surface of the impeller of the wind turbine generator set is subjected to wind power smaller than that of the lower side, the target wind sweeping area refers to a semicircular plane area swept from 0 degrees to 180 degrees when the blade rotates clockwise or a semicircular plane area swept from 180 degrees to 0 degrees when the blade rotates counterclockwise (as shown by hatching in fig. 5B).

Referring back to fig. 4, when the wind speed value is less than the predetermined wind speed value and the vibration value is greater than or equal to the predetermined vibration value, it means that the occurrence of the abnormal vibration phenomenon of the wind turbine generator system is not caused by the unbalanced force applied to the wind sweeping surface of the impeller of the wind turbine generator system, but is caused by other reasons, and at this time, a check is required, so that an alarm message may be sent in step S500. Furthermore, when the wind speed value is less than the predetermined wind speed value and the vibration value is less than the predetermined vibration value, or the wind speed value is greater than or equal to the predetermined wind speed value and the vibration value is less than the vibration value, it means that the stress on the wind-sweeping surface of the impeller of the wind turbine generator set is balanced, the current state of the wind turbine generator set can be maintained, and the pitch angle of the blade of the wind turbine generator set in the target wind-sweeping area is not adjusted.

Here, the pitch angle of the blade in the target wind sweeping region in the wind turbine generator set is adjusted according to the force condition of the wind sweeping surface of the impeller of the wind turbine generator set.

As an example, whether to acquire the stress condition of the wind-sweeping surface of the impeller of the wind turbine generator set may be determined, and specifically, the stress condition of the wind-sweeping surface of the impeller of the wind turbine generator set may be acquired in various manners, for example, acquired from an external device, acquired from an instruction input by a user after determining a target wind-sweeping area based on a terrain parameter and wind resource data of a wind farm in which the wind turbine generator set is located, and the like.

When the stress condition of the wind sweeping surface of the impeller of the wind generating set is obtained, the pitch angle of the blade in the target wind sweeping area in the wind generating set is adjusted according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set.

Specifically, when the stress condition of the wind-sweeping surface of the impeller of the wind turbine generator is acquired in the above manner, the magnitude relation between the wind power received by the upper side and the wind power received by the lower side of the wind-sweeping surface of the impeller of the wind turbine generator can be determined, so that the pitch angle of the corresponding blade in the target wind-sweeping area can be adjusted, and the dangerous phenomenon caused by unbalanced stress of the wind-sweeping surface of the impeller of the wind turbine generator can be prevented.

Here, in the exemplary embodiment of the present invention, the upper side of the windward side of the impeller of the wind turbine generator set refers to a semicircular plane area swept from 0 degrees horizontal to 180 degrees horizontal when the blade rotates clockwise, or a semicircular plane area swept from 180 degrees horizontal to 0 degrees horizontal when the blade rotates counterclockwise (as the shaded area in fig. 5A); the lower side of the windward side of the impeller of the wind turbine generator system refers to a semicircular plane area swept by the blade rotating from 180 degrees to 0 degrees from the horizontal when the blade rotates clockwise, or a semicircular plane area swept by the blade rotating from 0 degrees to 180 degrees from the horizontal when the blade rotates counterclockwise (as a shaded area in fig. 5B).

On the other hand, when the stress condition of the wind-sweeping surface of the impeller of the wind generating set is not acquired, the stress condition of the wind-sweeping surface of the impeller of the wind generating set is determined by the first pitch-retracting angle, and the pitch angle of the blades in the target wind-sweeping area in the wind generating set is adjusted according to the determined stress condition of the wind-sweeping surface of the impeller of the wind generating set.

Specifically, when the stress condition of the wind scanning surface of the impeller of the wind turbine generator set is not obtained, the wind turbine generator set cannot be adjusted because the magnitude relation between the wind power received by the upper side and the wind power received by the lower side of the wind scanning surface of the impeller of the wind turbine generator set is not obtained.

Specifically, first, a preset (e.g., from empirical values or statistical data) first feathering angle for determining a stress condition of a windward side of an impeller of a wind turbine generator set may be obtained. Here, the first feathering angle may be an angle value greater than zero degrees. For example, the first feathering angle may be 2 degrees.

Then, the pitch angle of the blade turning from the first position to the second position is controlled to recover the first propeller retracting angle at the first propeller retracting speed, and the pitch angle of the blade turning from the second position to the third position is controlled to recover the first propeller retracting angle at the first propeller retracting speed.

Here, as an example, as shown in fig. 6, initial positions of three blades of the wind turbine generator set at the time of installation are set to A, B and C, and during the clockwise rotation of the blades of the wind turbine generator set, the blade passing through the highest position O is the a position, the blade passing through the highest position O is the B position, and the blade passing through the highest position O is the C position, wherein the difference between the positions a, B and C is 120 degrees. Further, as an example, the position of the blade at the lowest point is 270 degrees, the position of the blade at the highest point is 90 degrees, the position of the blade at the horizontal point is 0 degrees during the rotation of the blade from the lowest point to the highest point, and the position of the blade at the vertical point is 90 degrees during the rotation of the blade from the highest point to the lowest point.

As a non-limiting example, in the setting position of the blade, the first position indicates a position in which the blade of the wind turbine group is horizontal when rotated from bottom to top; the second position indicates the position when the blade of the wind generating set is vertical when rotating from top to bottom, and the third position indicates the position when the blade of the wind generating set is horizontal when rotating from top to bottom. For example, in the set position of the blade shown in fig. 6 described above, the first position is an "M" position (e.g., 0 degrees horizontally) as in fig. 6; the second position is an "O" position (e.g., vertical 90 degrees) as in fig. 6; the third position is a "P" position as in fig. 6 (e.g., 180 degrees horizontally).

Further, as an example, the first feathering speed is determined based on a time required for an impeller of the wind turbine generator set to rotate ninety degrees and the first feathering angle. For example, the first pitch rate may be determined by equation 1 below:

wherein, V ₁ At the first pitch take-up speed, Y ₁ For the first feathering angle, T is the time required for the wind turbine to rotate ninety degrees.

In the following, an example of how the first feathering angle is used to determine the force condition of the wind-swept surface of the impeller of the wind park will be described in detail with reference to a specific example.

For example, assuming that the blades of the wind turbine are not fully deployed, the actual pitch angle of the blades to be adjusted is 10 degrees, and a first feathering angle Y is set ₁ And the rotation speed is 2 degrees, the time T required for the impeller of the wind generating set to rotate for 90 degrees is 2 minutes, and the first pitch-reducing speed is 1 degree/minute. In order to determine the stress condition of the wind-sweeping surface of the impeller of the wind generating set, the wind force received by the upper side of the wind-sweeping surface of the impeller of the wind generating set is larger than the wind force received by the lower side, and the actual pitch angle of the blade to be adjusted is expected to be reduced to 8 degrees when the blade to be adjusted rotates from 0 degree to 90 degrees, and is expected to be restored to 10 degrees when the blade to be adjusted rotates from 90 degrees to 180 degrees.

The specific operation is as follows: when the blade rotates to horizontal 0 degrees, the actual pitch angle of the blade turned from 0 degrees to 90 degrees is controlled to be withdrawn by 2 degrees at a speed of 1 degree/minute, and the actual pitch angle of the blade turned from 90 degrees to 180 degrees is controlled to be restored by 2 degrees.

The specific process is as follows: according to the first pitch-in speed of 1 degree/minute, the actual pitch angle of the blade at 0 degree is 10 degrees, the actual pitch angle of the blade is retracted by 1 degree at 45 degrees (i.e., the actual pitch angle of the blade is currently 9 degrees), the actual pitch angle is retracted by 1 degree at 90 degrees (i.e., the actual pitch angle of the blade is currently 8 degrees), the actual pitch angle is restored by 1 degree at 135 degrees (i.e., the actual pitch angle of the blade is currently 9 degrees), the actual pitch angle is restored by 1 degree at 180 degrees (i.e., the actual pitch angle of the blade is currently 10 degrees), and restoring by 2 degrees is equivalent to eliminating the influence caused by the previous retraction by 2 degrees.

The reason why the pitch angle cannot be directly retracted by 2 degrees is: due to the specific of the variable-pitch impeller, the pitch angle adjustment can only be better handled in a smaller way, particularly when the wind turbine generator set is in a high wind full-power stage, secondary risks can be generated if the moment angle of the blades is increased, for example, the number of the blades on the upper side of the wind sweeping surface of the impeller of the wind turbine generator set can be 2, at the moment, if the moment angles of the 2 blades are reduced by 2 degrees at the same time, the adjustment at the moment is overlarge, and in addition, from the mechanical and load angles, the moment angle adjustment of the blades is time-consuming and cannot be realized immediately.

Here, it should be understood that the first feathering angle of 2 degrees in the above example is only an example, and the first feathering angle of the present invention may be an angle value other than 2 degrees, and the present invention is not limited thereto.

Next, after adjusting the pitch angle of the blade at the position by using the first pitch-feathering angle, in order to verify whether the adjustment reduces the problem of abnormal vibration of the nacelle of the wind turbine generator set to further determine the stress of the wind-swept surface of the impeller of the wind turbine generator set, a current first vibration value of the wind turbine generator set may be compared with a second vibration value before controlling the blade to retract by the first pitch-feathering angle, specifically:

and when the first vibration value is smaller than the second vibration value, determining that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is larger than the wind power received by the lower side.

And when the first vibration value is larger than the second vibration value, determining that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side.

And when the first vibration value is equal to the second vibration value, sending alarm information.

By the mode, the pitch angle of the blade in the target wind sweeping area can be adjusted by utilizing a smaller first pitch-closing angle, so that the stress condition of the wind sweeping surface of the impeller of the wind generating set is verified.

On the other hand, as an example, after the stress condition of the wind-sweeping surface of the impeller of the wind generating set is acquired, the pitch angle of the blade in the target wind-sweeping area in the wind generating set can be adjusted by using the second pitch-adjusting angle according to the stress condition of the wind-sweeping surface of the impeller of the wind generating set, so as to correct the wind force received by the blade in the target wind-sweeping area of the wind generating set, and reduce the occurrence of dangerous phenomena caused by the unbalanced stress of the wind-sweeping surface of the impeller of the wind generating set.

Specifically, when the wind force received by the upper side of the windward side of the impeller of the wind generating set is larger than the wind force received by the lower side, the pitch angle of the blade turning from the first position to the second position is controlled to be retracted to the second feather retracting angle at the second feather retracting speed, and then the pitch angle of the blade turning from the second position to the third position is controlled to be retracted to the second feather retracting angle at the second feather retracting speed.

When the wind power received by the upper side of the windswept surface of the impeller of the wind generating set is smaller than the wind power received by the lower side, the pitch angle of the blade turned from the third position to the fourth position is controlled to recover the second pitch angle at the second pitch take-up speed, and the pitch angle of the blade turned from the fourth position to the first position is controlled to recover the second pitch angle at the second pitch take-up speed.

Here, the first position, the second position and the third position have the same meanings as mentioned above, and will not be described in detail here. Further, the fourth position indicates a position when the blade of the wind turbine generator set is in a vertical position when rotated from bottom to top, for example, in the above-described setting position of the blade shown in fig. 6, the fourth position is as in the "Q" position (for example, vertical 270 degrees) in fig. 6.

Further, as an example, a second feathering angle is also preset (e.g., from empirical values or statistical data), and the second feathering speed is determined based on a time required for the impeller of the wind turbine generator to rotate ninety degrees and the second feathering angle. For example, the second pitch rate may be determined by equation 2 below:

wherein, V ₂ At the second pitch-in speed, Y ₂ At the second feathering angle, T is the time required for the impeller of the wind turbine generator to rotate ninety degrees.

In the following, an example of how the pitch angle of the blades in the target windward area in the wind park is adjusted by means of the second feathering angle will be described in detail in connection with a specific example.

For example, assuming that the current wind speed is not high, the blades of the wind turbine generator system are fully unfolded, the actual pitch angle of the blades to be adjusted is 0 degree, and the second pitch-off angle Y is set ₂ At 4 degrees, the time T required for the impeller of the wind turbine to rotate ninety degrees is 4 minutes, and the second feathering speed is 1 degree/minute. When the wind power received by the upper side of the windward side of the impeller of the wind power generation set is larger than the wind power received by the lower side, it is desirable that the actual pitch angle of the blade to be adjusted is retracted to 4 degrees when the blade to be adjusted rotates from 0 degree to 90 degrees, and is restored to 0 degree when the blade to be adjusted rotates from 90 degrees to 180 degrees.

The specific operation is as follows: when the blade is rotated to the horizontal 0 degrees, the actual pitch angle of the blade from 0 degrees to 90 degrees is controlled to be retracted by 4 degrees at a speed of 1 degree/minute, and the actual pitch angle of the blade from 90 degrees to 180 degrees is controlled to be restored by 4 degrees.

The specific process is as follows: according to the second pitch-in speed of 1 degree/minute, the actual pitch angle of the blade at 0 degree is 0 degree, the actual pitch angle of the blade is retracted by 2 degrees at 45 degrees (i.e., the actual pitch angle of the blade is 2 degrees), the actual pitch angle is retracted by 2 degrees at 90 degrees (i.e., the actual pitch angle of the blade is 4 degrees), the actual pitch angle is restored by 2 degrees at 135 degrees (i.e., the actual pitch angle of the blade is 2 degrees), the actual pitch angle is restored by 2 degrees at 180 degrees (i.e., the actual pitch angle of the blade is 0 degrees), and restoring by 4 degrees is equivalent to eliminating the influence caused by the previous retraction by 4 degrees.

As another example, assuming that the current wind speed is high, the blades of the wind turbine generator set are not fully deployed, the actual pitch angle of the blades to be adjusted is 15 degrees, and the second pitch-in angle is set to Y ₂ At 4 degrees, wind power generationThe time T required for the impeller of the unit to rotate ninety degrees is 4 minutes, and the second pitch rate is 1 degree/minute. When the wind force received by the upper side of the windward side of the impeller of the wind generating set is larger than the wind force received by the lower side, the actual pitch angle of the blade to be adjusted is expected to be reduced to 11 degrees when the blade to be adjusted rotates from 0 degrees to 90 degrees, and the actual pitch angle of the blade to be adjusted is expected to be restored to 15 degrees when the blade to be adjusted rotates from 90 degrees to 180 degrees.

The specific process is as follows: according to the second pitch-in speed of 1 degree/minute, the actual pitch angle of the blade at 0 degree is 15 degrees, the actual pitch angle of the blade is retracted by 2 degrees at 45 degrees (i.e., the actual pitch angle of the blade is 13 degrees), the actual pitch angle is retracted by 2 degrees at 90 degrees (i.e., the actual pitch angle of the blade is 11 degrees), the actual pitch angle is restored by 2 degrees at 135 degrees (i.e., the actual pitch angle of the blade is 13 degrees), the actual pitch angle is restored by 2 degrees at 180 degrees (i.e., the actual pitch angle of the blade is 15 degrees), and restoring 4 degrees is equivalent to eliminating the influence caused by the previous retraction by 4 degrees.

On the other hand, a case where the wind force received by the upper side of the windward side of the impeller of the wind turbine generator system is smaller than the wind force received by the lower side will be described with reference to the following example.

Assuming that the blades of the wind generating set are not completely unfolded and the actual pitch angle of the blades to be adjusted is 14 degrees, a second pitch-retracting angle Y is set ₂ At 4 degrees, the time T required for the impeller of the wind turbine to rotate ninety degrees is 4 minutes, and the second feathering speed is 1 degree/minute. When the wind force received by the upper side of the windward side of the impeller of the wind turbine generator system is smaller than the wind force received by the lower side, it is desirable that the actual pitch angle of the blade to be adjusted is reduced to 10 degrees when the blade to be adjusted rotates from 180 degrees to 270 degrees, and is restored to 14 degrees when the blade to be adjusted rotates from 270 degrees to 360 degrees.

The specific operation is as follows: when the blade is rotated 180 degrees horizontally, the pitch angle of the blade from 180 degrees to 270 degrees is controlled to be retracted by 4 degrees at a speed of 1 degree/minute, and the pitch angle of the blade from 270 degrees to 360 degrees is controlled to be restored by 4 degrees.

The specific process is as follows: according to the second pitch-in speed, the actual pitch angle of the blade at 180 degrees is 14 degrees, the actual pitch angle of the blade is retracted by 2 degrees at 225 degrees (i.e., the actual pitch angle of the blade is 12 degrees), the actual pitch angle is retracted by 2 degrees at 270 degrees (i.e., the actual pitch angle of the blade is 10 degrees), the actual pitch angle is restored by 2 degrees at 315 degrees (i.e., the actual pitch angle of the blade is 12 degrees), the actual pitch angle is restored by 2 degrees at 360 degrees (i.e., the actual pitch angle of the blade is 14 degrees), and restoring 4 degrees is equivalent to eliminating the effect of the previous retraction by 4 degrees.

Here, it should be understood that the second feathering angle of 4 degrees in the above examples is only an example, and the first feathering angle in the present invention may be an angle value other than 4 degrees, and the present invention is not limited thereto.

Next, after adjusting the pitch angle of the blades of the wind park in the target wind sweeping area with the second feathering angle, the current vibration value of the wind park may be compared with a predetermined vibration value, and it is determined whether the above adjustment has resolved the vibration anomaly of the wind park according to the result of the comparison, specifically:

when the current vibration value of the wind generating set is greater than or equal to the predetermined vibration value, it means that the abnormal vibration problem of the wind generating set is not overcome after the blade of the wind generating set in the target wind sweeping area is adjusted by using the second pitch adjusting angle, and therefore, the blade of the wind generating set in the target wind sweeping area needs to be continuously adjusted to overcome the abnormal vibration problem of the wind generating set. In particular, the blades of the wind generating set in the target wind sweeping area can be adjusted by using a third pitch angle which is larger than the first pitch angle and the second pitch angle.

For example, when the wind force received by the upper side of the windward side of the impeller of the wind turbine generator system is larger than the wind force received by the lower side, the pitch angle of the blade turned from the first position to the second position is controlled to be retracted by a third feathering angle at a third feathering speed, and the pitch angle of the blade turned from the second position to the third position is controlled to be retracted by the third feathering angle at the third feathering speed.

And when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side, controlling the pitch angle of the blade turned to the fourth position from the third position to recover the third blade retracting angle at the third blade retracting speed, and controlling the pitch angle of the blade turned to the first position from the fourth position to recover the third blade retracting angle at the third blade retracting speed.

Here, the first position, the second position, the third position and the fourth position have the same meanings as mentioned above, and will not be described herein again. Further, the third feathering speed is determined based on a time required for the impeller of the wind turbine generator set to rotate ninety degrees and the third feathering angle. For example, the third feathering speed can be determined by the following equation 3:

wherein, V ₃ At a third pitch-in speed, Y ₃ And T is the time required for the impeller of the wind generating set to rotate ninety degrees at the third oar retracting angle.

Further, as an example, the first feathering angle is less than the second feathering angle, and the second feathering angle is less than the third feathering angle. Here, a manner of adjusting the blades of the wind generating set located in the target wind sweeping area by using the third pitch-reducing angle is the same as a manner of adjusting the blades of the wind generating set located in the target wind sweeping area by using the second pitch-reducing angle, and will not be described herein again.

Preferably, after the pitch angle of the blades of the wind turbine generator set in the target wind sweeping area is adjusted by the third pitch adjusting angle, if the wind turbine generator set still has abnormal vibration after the comparison of the vibration values, the pitch angle of the blades of the wind turbine generator set in the target wind sweeping area may be adjusted by continuously increasing the pitch angle adjustment range, for example, the pitch angle of the blades of the wind turbine generator set in the target wind sweeping area may be adjusted by the fourth pitch adjusting angle, so as to achieve the purpose of controlling the abnormal vibration of the wind turbine generator set caused by the unbalanced stress of the wind sweeping surface of the impeller.

It can be seen that, in the method for adjusting the pitch angle of the blades of the wind turbine generator system according to the exemplary embodiment of the present invention, the problem of abnormal vibration of the wind turbine generator system caused by unbalanced stress on the wind-sweeping surface of the impeller in the wind turbine generator system in the prior art can be solved by adjusting the pitch angle of the blades in the target wind-sweeping region.

Fig. 7 shows a block diagram of an arrangement for adjusting the pitch angle of a blade of a wind park according to an exemplary embodiment of the invention.

As shown in fig. 7, the apparatus for adjusting the pitch angle of the blades of the wind turbine according to the exemplary embodiment of the present invention includes: an acquisition module 100, a parsing module 200, a determination module 300, and an adjustment module 400. As an example, the module may be implemented by a general-purpose hardware processor such as a sensor, a data signal processor, a field programmable gate array, or the like, or may be implemented by a special-purpose hardware processor such as a special-purpose chip, or may be implemented in a software manner entirely by a computer program.

Specifically, the obtaining module 100 obtains wind speed data and vibration data of the wind turbine generator system in real time. Here, as an example, the vibration data of the wind park refers to vibration data of a nacelle of the wind park.

The analysis module 200 analyzes the acquired wind speed data and vibration data to obtain a wind speed value and a vibration value.

The determination module 300 determines whether the wind speed value is greater than or equal to a predetermined wind speed value and determines whether the oscillation value is greater than or equal to a predetermined oscillation value.

When the wind speed value is greater than or equal to the predetermined wind speed value and the vibration value is greater than or equal to the predetermined vibration value, it means that the force applied to the windswept surface of the impeller of the wind turbine generator is unbalanced, and the imbalance causes abnormal vibration of the wind turbine generator, in which case, the adjustment module 400 adjusts the pitch angle of the blade in the target windswept area in the wind turbine generator according to the force applied to the windswept surface of the impeller of the wind turbine generator to correct the wind force applied to the blade of the wind turbine generator, thereby reducing the occurrence of dangerous phenomena caused by unbalanced force applied to the windswept surface of the impeller of the wind turbine generator.

when the upper side of the wind sweeping surface of the impeller of the wind generating set is subjected to wind power smaller than that of the lower side, the target wind sweeping area refers to a semicircular plane area swept by the blade rotating from 0 degrees to 180 degrees horizontally or a semicircular plane area swept by the blade rotating from 180 degrees to 0 degrees horizontally when the blade rotates counterclockwise (as shown by the hatching in fig. 5B).

In addition, the device for adjusting the pitch angle of the blade of the wind turbine generator system further comprises a sending module (not shown in fig. 7), and accordingly, when the wind speed value is less than the predetermined wind speed value and the vibration value is greater than or equal to the predetermined vibration value, it means that the abnormal vibration phenomenon of the wind turbine generator system occurs not due to unbalanced stress on the wind-sweeping surface of the impeller of the wind turbine generator system but due to other reasons, and at this time, the sending module needs to perform a check, so that the sending module sends alarm information. In addition, when the wind speed value is less than the predetermined wind speed value and the vibration value is less than the predetermined vibration value, or the wind speed value is greater than or equal to the predetermined wind speed value and the vibration value is less than the vibration value, it means that the stress on the wind-sweeping surface of the impeller of the wind turbine generator set is balanced, the current state of the wind turbine generator set can be maintained, and the adjustment module 400 does not adjust the pitch angle of the blades of the wind turbine generator set in the target wind-sweeping area.

As an example, the adjusting module 400 may first determine whether to acquire the stress condition of the wind sweeping surface of the impeller of the wind generating set, and specifically, may acquire the stress condition of the wind sweeping surface of the impeller of the wind generating set in various manners, for example, acquire the stress condition from an external device through an input interface, acquire an instruction input by a user after determining a target wind sweeping area based on topographic parameters and wind resource data of a wind farm in which the wind generating set is located, and the like.

When the stress condition of the wind sweeping surface of the impeller of the wind generating set is obtained, the adjusting module 400 adjusts the pitch angle of the blade in the target wind sweeping area in the wind generating set according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set.

Here, in the exemplary embodiment of the present invention, the upper side of the wind sweeping surface of the impeller of the wind turbine generator set refers to a semicircular plane area swept by the blade rotating from 0 degree to 180 degrees horizontally when the blade rotates clockwise, or a semicircular plane area swept by the blade rotating from 180 degrees to 0 degree horizontally when the blade rotates counterclockwise (as a shaded area in fig. 5A); the lower side of the windward side of the impeller of the wind turbine generator system refers to a semicircular plane area swept by the blade rotating from 180 degrees to 0 degrees from the horizontal when the blade rotates clockwise, or a semicircular plane area swept by the blade rotating from 0 degrees to 180 degrees from the horizontal when the blade rotates counterclockwise (as a shaded area in fig. 5B).

On the other hand, when the stress condition of the wind-sweeping surface of the impeller of the wind generating set is not acquired, the adjusting module 400 determines the stress condition of the wind-sweeping surface of the impeller of the wind generating set by using the first pitch-retracting angle, and adjusts the pitch angle of the blades in the target wind-sweeping region in the wind generating set according to the determined stress condition of the wind-sweeping surface of the impeller of the wind generating set.

Then, the adjusting module 400 controls the pitch angle of the blade turning from the first position to the second position to retract to the first pitch-retracting angle at the first pitch-retracting speed, and controls the pitch angle of the blade turning from the second position to the third position to restore to the first pitch-retracting angle at the first pitch-retracting speed. Here, the first feathering speed is determined based on the time required for the impeller of the wind turbine generator set to rotate ninety degrees and the first feathering angle, and the specific acquisition manner of the first feathering speed is described in the foregoing, and is not described again here.

Further, as an example, the first position indicates a position when a blade of the wind turbine generator set is horizontal when rotated from bottom to top; the second position indicates the position when the blade of the wind generating set is vertical when rotating from top to bottom, and the third position indicates the position when the blade of the wind generating set is horizontal when rotating from top to bottom.

Next, the adjusting module 400 compares a current first vibration value of the wind turbine with a second vibration value before the control of the retraction of the blade by the first pitch angle after the adjustment of the pitch angle of the blade by the first pitch angle, and determines a stress condition of the wind-sweeping surface of the blade of the wind turbine according to the comparison result, specifically:

when the first vibration value is smaller than the second vibration value, the adjustment module 400 determines that the upper side of the windswept surface of the impeller of the wind turbine generator set is subjected to a larger wind force than the lower side.

When the first vibration value is greater than the second vibration value, the adjustment module 400 determines that the upper side of the windswept surface of the impeller of the wind turbine generator set is subjected to a smaller wind force than the lower side.

And when the first vibration value is equal to the second vibration value, sending alarm information by the sending module.

By the mode, the pitch angle of the blade in the target wind sweeping area can be adjusted by utilizing a smaller first pitch-retracting angle, so that the stress condition of the wind sweeping surface of the impeller of the wind generating set is verified.

On the other hand, as an example, after the stress condition of the wind-sweeping surface of the impeller of the wind turbine generator set is obtained, the adjusting module 400 may adjust the pitch angle of the blade of the wind turbine generator set in the target wind-sweeping region by using the second feathering angle according to the stress condition of the wind-sweeping surface of the impeller of the wind turbine generator set, so as to correct the wind force received by the blade of the wind turbine generator set in the target wind-sweeping region, and reduce the occurrence of dangerous phenomena caused by the unbalanced stress of the wind-sweeping surface of the impeller of the wind turbine generator.

Specifically, when the upper side of the windward side of the impeller of the wind turbine generator system is subjected to wind power greater than the lower side of the windward side, the adjustment module 400 controls the pitch angle of the blade turned from the first position to the second position to be retracted to the second pitch angle at the second pitch retracting speed, and controls the pitch angle of the blade turned from the second position to the third position to be retracted to the second pitch retracting angle at the second pitch retracting speed.

In addition, when the wind power received by the upper side of the windward side of the impeller of the wind generating set is smaller than the wind power received by the lower side of the windward side, the adjusting module 400 controls the pitch angle of the blade turned from the third position to the fourth position to retract to the second feather-retracting angle at the second feather-retracting speed, and then controls the pitch angle of the blade turned from the fourth position to the first position to retract to the second feather-retracting angle at the second feather-retracting speed.

Here, the first position, the second position, the third position and the fourth position have the same meanings as mentioned above, and will not be described herein again.

Further, as an example, a second feathering angle is also preset (e.g., from empirical values or statistical data), and the second feathering speed is determined based on a time required for the impeller of the wind turbine generator to rotate ninety degrees and the second feathering angle. The specific manner of acquiring the second pitch take-up speed is described above, and is not described herein again.

Next, after adjusting the pitch angle of the blades of the wind park in the target wind sweeping area with the second feather angle, the adjustment module 400 further compares the current vibration value of the wind park with a predetermined vibration value, and determines whether the above adjustment has resolved the vibration anomaly of the wind park according to the result of the comparison, in particular:

when the current vibration value of the wind generating set is greater than or equal to the predetermined vibration value, it means that the abnormal vibration problem of the wind generating set is not overcome after the blade of the wind generating set in the target wind sweeping region is adjusted by using the second pitch adjusting angle, and therefore, the adjustment module 400 needs to continuously adjust the blade of the wind generating set in the target wind sweeping region to overcome the abnormal vibration problem of the wind generating set. Specifically, the blades of the wind turbine generator set in the target wind sweeping area can be adjusted by using a third feathering angle which is larger than the first feathering angle and the second feathering angle.

For example, when the wind force received by the upper side of the windward side of the impeller of the wind turbine generator system is greater than the wind force received by the lower side of the windward side, the adjustment module 400 controls the pitch angle of the blade turned from the first position to the second position to be retracted to the third feather retracting angle at the third feather retracting speed, and controls the pitch angle of the blade turned from the second position to the third position to be retracted to the third feather retracting angle at the third feather retracting speed.

Under the condition that the wind power received by the upper side of the windsweeper of the impeller of the wind generating set is smaller than the wind power received by the lower side of the windsweeper, the adjusting module 400 controls the pitch angle of the blade turning from the third position to the fourth position to retract to a third pitch-retracting angle at a third pitch-retracting speed, and then controls the pitch angle of the blade turning from the fourth position to the first position to retract to the third pitch-retracting angle at the third pitch-retracting speed.

Here, the first position, the second position, the third position and the fourth position have the same meanings as mentioned above, and will not be described herein again. Further, the third feathering speed is determined based on a time required for the impeller of the wind turbine generator set to rotate ninety degrees and the third feathering angle. The specific acquiring manner of the third pitch take-up speed is described in the foregoing, and is not described herein again.

Further, as an example, the first feathering angle is less than the second feathering angle, and the second feathering angle is less than the third feathering angle.

Therefore, in the device for adjusting the pitch angle of the blades of the wind generating set according to the exemplary embodiment of the invention, the problem of abnormal vibration of the wind generating set caused by unbalanced stress of the wind scanning surface of the impeller in the wind generating set in the prior art can be solved by adjusting the pitch angle of the blades in the target wind scanning area.

As shown in fig. 8, a system for adjusting a pitch angle of a blade of a wind turbine according to an exemplary embodiment of the present invention includes: comparator 10, wind speed sensor 20, vibration detection device 30, at least one pitch system actuator 40 and controller 50.

Specifically, the controller 50 controls the wind speed sensor 20 to acquire wind speed data of the wind turbine generator set in real time and controls the vibration detecting device 30 to acquire vibration data of the wind turbine generator set in real time, and then the controller 50 parses the acquired wind speed data and vibration data to obtain a wind speed value and a vibration value, and after obtaining the wind speed value and the vibration value, the controller 50 controls the comparator 10 to determine whether the wind speed value is greater than or equal to a predetermined wind speed value and determine whether the vibration value is greater than or equal to a predetermined vibration value. Here, as an example, the vibration data of the wind park refers to vibration data of a nacelle of the wind park.

When the wind speed value is greater than or equal to the predetermined wind speed value and the vibration value is greater than or equal to the predetermined vibration value, it means that the wind-sweeping surface of the impeller of the wind generating set is unbalanced, and the unbalance causes abnormal vibration of the wind generating set, in which case, the controller 50 controls at least one pitch control system actuator 40 to adjust the pitch angle of the blades in the target wind-sweeping area of the wind generating set according to the stress condition of the wind-sweeping surface of the impeller of the wind generating set, so as to correct the wind power received by the blades of the wind generating set, thereby reducing the occurrence of secondary danger phenomena caused by the unbalanced stress condition of the wind-sweeping surface of the impeller of the wind generating set.

Here, when the upper side of the windswept surface of the impeller of the wind turbine generator set receives a wind force greater than the lower side, the target windswept area refers to a semicircular plane area swept by the blade rotating from 0 degrees to 180 degrees horizontally when the blade rotates clockwise or a semicircular plane area swept by the blade rotating from 180 degrees to 0 degrees horizontally when the blade rotates counterclockwise (as shown by hatching in fig. 5A);

In addition, the system for adjusting the pitch angle of the blades of the wind turbine generator system further includes a transmitter (not shown in fig. 8), and accordingly, when the wind speed value is less than the predetermined wind speed value and the vibration value is greater than or equal to the predetermined vibration value, it means that the occurrence of the abnormal vibration phenomenon of the wind turbine generator system is not caused by the unbalanced force applied to the windswept surface of the blades of the wind turbine generator system but caused by other reasons, and at this time, a check is required, so the controller 50 may control the transmitter to transmit an alarm message. In addition, when the wind speed value is less than the predetermined wind speed value and the vibration value is less than the predetermined vibration value, or the wind speed value is greater than or equal to the predetermined wind speed value and the vibration value is less than the predetermined vibration value, it means that the force applied to the wind sweeping surface of the impeller of the wind turbine generator set is balanced, and the current state of the wind turbine generator set can be maintained.

As an example, the controller 50 may be configured to: the method for determining whether to acquire the stress condition of the windward side of the impeller of the wind generating set may be, for example, acquired from an external device through an input interface, acquired from an instruction input by a user after determining a target windward area based on topographic parameters and wind resource data of a wind farm where the wind generating set is located, and the like.

When the stress condition of the wind-sweeping surface of the impeller of the wind generating set is obtained, the controller 50 adjusts the pitch angle of the blade in the target wind-sweeping region in the wind generating set according to the determined stress condition of the wind-sweeping surface of the impeller of the wind generating set.

On the other hand, when the stress condition of the wind-sweeping surface of the impeller of the wind generating set is not acquired, the controller 50 determines the stress condition of the wind-sweeping surface of the impeller of the wind generating set by using the first pitch-retracting angle, and adjusts the pitch angle of the blades in the target wind-sweeping region in the wind generating set according to the determined stress condition of the wind-sweeping surface of the impeller of the wind generating set.

Specifically, when the force condition of the wind-sweeping surface of the impeller of the wind turbine generator set is not obtained, the force condition of the wind-sweeping surface of the impeller of the wind turbine generator set is determined by using the first pitch-retracting angle, and the pitch angle of the blades of the wind turbine generator set in the target wind-sweeping area is adjusted according to the determined force condition of the wind-sweeping surface of the impeller of the wind turbine generator set.

Specifically, the system may further comprise a central monitoring system and a transmitter (not shown in fig. 8), wherein the controller 50 is configured to: the controller 50 may obtain a preset first feathering angle (e.g., based on empirical or statistical data) from a central monitoring system for determining a stress condition of a wind-sweeping surface of an impeller of the wind turbine generator set. Here, the first feathering angle may be an angle value greater than zero degrees.

Then, the controller 50 controls the at least one pitch system actuator 40 to control the pitch angle of the blade turned from the first position to the second position to retract to the first pitch angle at the first pitch retraction speed, and then controls the pitch angle of the blade turned from the second position to the third position to retract to the first pitch angle at the first pitch retraction speed. Here, the first feathering speed is determined based on the time required for the impeller of the wind turbine generator system to rotate ninety degrees and the first feathering angle, and the specific obtaining manner of the first feathering speed is described in the foregoing, and is not described again here.

Next, after adjusting the pitch angle of the blade at the position by using the first pitch-retracting angle, the controller 40 controls the comparator 10 to compare the current first vibration value of the wind turbine with the second vibration value before controlling the blade to retract by the first pitch-retracting angle, and determines the stress condition of the wind-sweeping surface of the impeller of the wind turbine according to the comparison result, specifically:

when the first vibration value is smaller than the second vibration value, the controller 50 determines that the upper side of the windswept surface of the impeller of the wind turbine generator set is subjected to a larger wind force than the lower side.

When the first vibration value is greater than the second vibration value, the controller 50 determines that the upper side of the windswept surface of the impeller of the wind turbine generator set is subjected to less wind force than the lower side.

When the first vibration value is equal to the second vibration value, the controller 50 controls the transmitter to transmit alarm information.

On the other hand, as an example, after the stress condition of the swept surface of the impeller of the wind generating set is obtained, the controller 50 may control the at least one pitch system actuator 40 to adjust the pitch angle of the blades of the wind generating set in the target swept area by using the second pitch adjusting angle according to the stress condition of the swept surface of the impeller of the wind generating set, so as to correct the wind force received by the blades of the wind generating set in the target swept area, and reduce the occurrence of the secondary hazard phenomenon caused by the unbalanced stress condition of the swept surface of the impeller of the wind generating set.

Specifically, when the upper side of the windward side of the impeller of the wind turbine generator set is subjected to a wind force greater than the lower side, the controller 50 controls the at least one pitch system actuator 40 to control the pitch angle of the blade turned from the first position to the second position to be retracted by the second pitch angle at the second pitch rate, and then controls the pitch angle of the blade turned from the second position to the third position to be retracted by the second pitch angle at the second pitch rate.

In addition, when the wind power received by the upper side of the windward side of the impeller of the wind turbine generator set is smaller than the wind power received by the lower side, the controller 50 controls the at least one pitch system actuator 40 to control the pitch angle of the blade turned from the third position to the fourth position to be retracted to the second pitch angle at the second pitch-retracting speed, and then controls the pitch angle of the blade turned from the fourth position to the first position to be retracted to the second pitch-retracting angle at the second pitch-retracting speed.

Further, as an example, a second feathering angle is also preset, and the second feathering speed is determined based on the time required for the impeller of the wind turbine generator set to rotate ninety degrees and the second feathering angle. The specific acquisition mode of the second paddle retracting speed is described in the foregoing, and is not described herein again.

Next, after adjusting the pitch angle of the blades of the wind park in the target wind sweeping area by using the second feather angle, the controller 50 further controls the comparator to compare the current vibration value of the wind park with a predetermined vibration value, and determines whether the adjustment has resolved the vibration abnormality of the wind park according to the comparison result, specifically:

if the current vibration value is greater than or equal to the predetermined vibration value, it means that the abnormal vibration problem of the wind turbine generator set is not overcome after the blades of the wind turbine generator set in the target wind sweeping area are adjusted by using the second pitching angle, and therefore, the controller 50 needs to continuously control the at least one pitch system actuator 40 to adjust the blades of the wind turbine generator set in the target wind sweeping area so as to overcome the abnormal vibration problem of the wind turbine generator set. Specifically, the blades of the wind generating set in the target wind sweeping area can be adjusted by using a third feathering angle which is larger than the first feathering angle and the second feathering angle.

For example, in the case that the wind force received on the upper side of the windward side of the impeller of the wind turbine generator set is greater than the wind force received on the lower side, the controller 50 controls the at least one pitch system actuator 40 to control the pitch angle of the blade turned from the first position to the second position to be retracted by the third pitch angle at the third pitch rate, and then controls the pitch angle of the blade turned from the second position to the third position to be retracted by the third pitch angle at the third pitch rate.

Under the condition that the wind power received by the upper side of the windward side of the impeller of the wind generating set is smaller than the wind power received by the lower side of the windward side of the impeller of the wind generating set, the controller 50 controls the pitch angle of the blade turned to the fourth position from the third position by the at least one pitch system actuating mechanism 40 to be recovered to the third pitch-withdrawing angle at the third pitch-withdrawing speed, and then controls the pitch angle of the blade turned to the first position from the fourth position to be recovered to the third pitch-withdrawing angle at the third pitch-withdrawing speed.

Here, the first position, the second position, the third position and the fourth position have the same meanings as mentioned above, and will not be described herein again. Further, the third feather speed is determined based on a time required for the impeller of the wind turbine generator set to rotate ninety degrees and the third feather angle. The specific manner of acquiring the third pitch take-up speed is described above, and is not described herein again.

Further, as an example, the first pitch angle is less than the second pitch angle, and the second pitch angle is less than the third pitch angle.

Preferably, after the pitch angle of the blades of the wind turbine generator set in the target wind sweeping area is adjusted by the third feather adjustment angle, and after the comparison by the vibration value comparison method, if the wind turbine generator set still has abnormal vibration, the pitch angle adjustment range may be continuously increased to adjust the pitch angle, for example, the pitch angle of the blades of the wind turbine generator set in the target wind sweeping area is adjusted by using a fourth feather adjustment angle larger than the third feather adjustment angle, so as to control the abnormal vibration of the wind turbine generator set.

In summary, according to the method, the device and the system for adjusting the pitch angle of the blade of the wind generating set in the exemplary embodiment of the invention, the problem of abnormal vibration of the wind generating set caused by unbalanced stress on the wind-sweeping surface of the impeller in the prior art can be solved by adjusting the pitch angle of the blade in the target wind-sweeping area.

There is also provided, according to an embodiment of the invention, a computer readable storage medium having stored thereon a computer program which, when being executed by a processor, carries out the method of adjusting a pitch angle of a blade of a wind park as set forth above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

Claims

1. A method of adjusting a pitch angle of a blade of a wind park, comprising:

acquiring wind speed data and vibration data of a wind generating set in real time;

analyzing the acquired wind speed data and vibration data to obtain a wind speed value and a vibration value;

determining whether the wind speed value is greater than or equal to a predetermined wind speed value and determining whether the oscillation value is greater than or equal to a predetermined oscillation value;

when the wind speed value is larger than or equal to the preset wind speed value and the vibration value is larger than or equal to the preset vibration value, adjusting the pitch angle of the blades in the target wind sweeping area according to the stress condition of the wind sweeping surface of the impeller of the wind generating set,

when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind generating set is larger than the wind power received by the lower side of the wind sweeping surface, the target wind sweeping area refers to a semicircular plane area swept by the blade from 0 degree to 180 degrees when the blade rotates clockwise, or a semicircular plane area swept by the blade from 180 degrees to 0 degree when the blade rotates anticlockwise;

when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side, the target wind sweeping area refers to a semicircular plane area swept by the blade rotating from 180 degrees to 0 degrees from the horizontal when the blade rotates clockwise, or the semicircular plane area swept by the blade rotating from 0 degrees to 180 degrees from the horizontal when the blade rotates anticlockwise,

the pitch angle of the corresponding blade in the target wind sweeping area is adjusted according to the magnitude relation between the wind power received by the upper side and the wind power received by the lower side of the wind sweeping surface of the impeller of the wind generating set.

2. The method according to claim 1, wherein the step of adjusting the pitch angle of the blades in the wind park in the target wind sweep area according to the force condition of the wind sweep of the impeller of the wind park comprises:

determining whether the stress condition of the wind sweeping surface of the impeller of the wind generating set is acquired,

when the stress condition of the wind sweeping surface of the impeller of the wind generating set is obtained, adjusting the pitch angle of the blade in the target wind sweeping area in the wind generating set according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set;

when the stress condition of the wind-sweeping surface of the impeller of the wind generating set is not acquired, determining the stress condition of the wind-sweeping surface of the impeller of the wind generating set by using a first blade retracting angle, and adjusting the pitch angle of the blade in the target wind-sweeping area in the wind generating set according to the determined stress condition of the wind-sweeping surface of the impeller of the wind generating set.

3. The method of claim 2, wherein the step of determining the force profile of the wind-swept surface of the rotor of the wind turbine using the first feathering angle comprises:

controlling the pitch angle of the blade turning from the first position to the second position to recover the first pitch angle at the first pitch-withdrawing speed, and then controlling the pitch angle of the blade turning from the second position to the third position to recover the first pitch angle at the first pitch-withdrawing speed;

comparing the current first vibration value of the wind generating set with a second vibration value before the blades are controlled to retract to the first pitch-retracting angle;

when the first vibration value is smaller than the second vibration value, determining that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is larger than the wind power received by the lower side;

when the first vibration value is larger than the second vibration value, determining that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side;

4. The method according to claim 3, wherein the step of adjusting the pitch angle of the blades in the wind park in the target wind sweeping zone according to the determined force condition of the wind sweeping surface of the impeller of the wind park comprises:

and adjusting the pitch angle of the blade in the target wind sweeping area in the wind generating set by using a second pitch-retracting angle according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set.

5. The method according to claim 4, wherein the step of adjusting the pitch angle of the blades in the wind generating set in the target wind sweeping area by using the second feathering angle according to the determined stress condition of the wind sweeping surface of the impeller of the wind generating set comprises the following steps:

when the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is larger than the wind power received by the lower side of the windsweeping surface of the impeller of the wind generating set, controlling the pitch angle of the blade turning from the first position to the second position to withdraw the second pitch angle at a second pitch withdrawing speed, and then controlling the pitch angle of the blade turning from the second position to the third position to recover the second pitch angle at the second pitch withdrawing speed;

when the wind power received by the upper side of the windward side of the impeller of the wind generating set is smaller than the wind power received by the lower side, the pitch angle of the blade turned to the fourth position from the third position is controlled to be retracted to a second pitch retracting angle at a second pitch retracting speed, then the pitch angle of the blade turned to the first position from the fourth position is controlled to be retracted to the second pitch retracting angle at the second pitch retracting speed,

the first position indicates the position of a blade of the wind generating set when the blade rotates from bottom to top and is horizontal;

the second position indicates a position when a blade of the wind generating set is vertical when rotating from top to bottom;

the third position indicates the position of the blade of the wind generating set when the blade rotates from top to bottom and is horizontal;

and the fourth position indicates the position of the blade of the wind generating set when the blade rotates from bottom to top and is vertical.

6. The method according to claim 5, wherein the step of adjusting the pitch angle of the blades in the wind park in the target wind sweep area according to the determined force condition of the wind sweep of the impeller of the wind park further comprises:

after adjusting the pitch angle of the blades of the wind generating set in the target wind sweeping area by using the second feathering angle, comparing the current vibration value of the wind generating set with the preset vibration value;

if the current vibration value is larger than or equal to the preset vibration value, controlling the pitch angle of the blade turning to the second position from the first position to be retracted to a third feathering angle at a third feathering speed under the condition that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is larger than the wind power received by the lower side, and then controlling the pitch angle of the blade turning to the third position from the second position to be retracted to the third feathering angle at the third feathering speed;

and under the condition that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side of the windsweeping surface, controlling the pitch angle of the blade turned to the fourth position from the third position to be retracted to a third feathering angle at a third feathering speed, and then controlling the pitch angle of the blade turned to the first position from the fourth position to be retracted to the third feathering angle at the third feathering speed.

7. The method of claim 6,

the first feathering speed is determined based on the time required for an impeller of the wind generating set to rotate ninety degrees and a first feathering angle;

the second feathering speed is determined based on the time required for the impeller of the wind generating set to rotate ninety degrees and a second feathering angle;

the third feathering speed is determined based on the time required for the impeller of the wind generating set to rotate ninety degrees and a third feathering angle;

the first oar-retracting angle is smaller than the second oar-retracting angle, and the second oar-retracting angle is smaller than the third oar-retracting angle.

8. An apparatus for adjusting a pitch angle of a blade of a wind turbine, comprising:

the acquisition module is used for acquiring wind speed data and vibration data of the wind generating set in real time;

the analysis module is used for analyzing the acquired wind speed data and vibration data to acquire a wind speed value and a vibration value;

a determination module that determines whether the wind speed value is greater than or equal to a predetermined wind speed value and determines whether the oscillation value is greater than or equal to a predetermined oscillation value;

an adjusting module, which adjusts the pitch angle of the blades in the wind generating set in the target wind sweeping area according to the stress condition of the wind sweeping surface of the impeller of the wind generating set when the wind speed value is greater than or equal to the preset wind speed value and the vibration value is greater than or equal to the preset vibration value,

when the wind power received by the upper side of the wind sweeping surface of the impeller of the wind generating set is larger than the wind power received by the lower side of the wind sweeping surface, the target wind sweeping area refers to a semicircular plane area swept by the blade rotating from 0 degree to 180 degrees horizontally during clockwise rotation, or a semicircular plane area swept by the blade rotating from 180 degrees to 0 degree horizontally during anticlockwise rotation;

the adjusting module adjusts the pitch angle of the corresponding blade in the target wind sweeping area according to the magnitude relation between the wind power received by the upper side and the wind power received by the lower side of the wind sweeping surface of the impeller of the wind generating set.

9. The apparatus of claim 8, wherein the adjustment module determines whether a force condition of a wind-sweeping surface of an impeller of the wind turbine generator set is obtained, and when the force condition of the wind-sweeping surface of the impeller of the wind turbine generator set is obtained, the adjustment module adjusts a pitch angle of a blade in the wind turbine generator set in a target wind-sweeping region according to the determined force condition of the wind-sweeping surface of the impeller of the wind turbine generator set; when the stress condition of the wind-sweeping surface of the impeller of the wind generating set is not acquired, the adjusting module determines the stress condition of the wind-sweeping surface of the impeller of the wind generating set by using the first pitch-retracting angle, and adjusts the pitch angle of the blade in the target wind-sweeping area in the wind generating set according to the determined stress condition of the wind-sweeping surface of the impeller of the wind generating set.

10. The apparatus of claim 9, wherein the apparatus further comprises:

a sending module for sending the data to the client,

wherein the adjusting module is used for controlling the pitch angle of the blade turning from the first position to the second position to recover the first pitch-retracting angle at the first pitch-retracting speed, and then controlling the pitch angle of the blade turning from the second position to the third position to recover the first pitch-retracting angle at the first pitch-retracting speed,

the adjusting module compares a current first vibration value of the wind generating set with a second vibration value before the blades are controlled to retract to the first blade retracting angle,

when the first vibration value is smaller than the second vibration value, the adjusting module determines that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is larger than the wind power received by the lower side,

when the first vibration value is larger than the second vibration value, the adjusting module determines that the wind power received by the upper side of the windsweeping surface of the impeller of the wind generating set is smaller than the wind power received by the lower side,

and when the first vibration value is equal to the second vibration value, the sending module sends alarm information.

11. The apparatus according to claim 10, wherein the adjusting module adjusts the pitch angle of the blades in the wind turbine generator set in the target wind sweeping area by using a second feathering angle according to the determined stress condition of the wind sweeping surface of the impeller of the wind turbine generator set.

12. The apparatus according to claim 11, wherein the adjustment module controls the pitch angle of the blade turned from the first position to the second position to be retracted to a second feathering angle at a second feathering speed and controls the pitch angle of the blade turned from the second position to the third position to be retracted to the second feathering angle at the second feathering speed when the upper side of the windswept surface of the impeller of the wind turbine generator set is subjected to a wind force greater than the lower side;

when the wind power received by the upper side of the windsweeper of the impeller of the wind generating set is smaller than the wind power received by the lower side, the adjusting module controls the pitch angle of the blade turning from the third position to the fourth position to withdraw the second pitch angle at the second pitch take-up speed, then controls the pitch angle of the blade turning from the fourth position to the first position to recover the second pitch angle at the second pitch take-up speed,

the fourth position indicates the position when the blade of the wind generating set is vertical when rotating from bottom to top.

13. The apparatus of claim 12, wherein the adjustment module further compares a current vibration value of the wind park to the predetermined vibration value after adjusting a pitch angle of blades of the wind park in a target windward region with a second feathering angle,

if the current vibration value is greater than or equal to the preset vibration value, the adjusting module controls the pitch angle of the blade turning from the first position to the second position to retract to a third feather retracting angle at a third feather retracting speed and then controls the pitch angle of the blade turning from the second position to the third position to retract to the third feather retracting angle at the third feather retracting speed under the condition that the wind power received by the upper side of the windswept surface of the impeller of the wind generating set is greater than the wind power received by the lower side,

and under the condition that the wind power received by the upper side of the windsweeper of the impeller of the wind generating set is smaller than the wind power received by the lower side, the adjusting module controls the pitch angle of the blade turning to the fourth position from the third position to retract to a third pitch angle at a third pitch-retracting speed, and then controls the pitch angle of the blade turning to the first position from the fourth position to retract to the third pitch angle at the third pitch-retracting speed.

14. The apparatus of claim 13,

the third feathering speed is determined based on a time required for an impeller of the wind turbine generator set to rotate ninety degrees and a third feathering angle,

15. A system for adjusting a pitch angle of a blade of a wind turbine, comprising:

a comparator;

a wind speed sensor;

a vibration detection device;

at least one pitch system actuator; and

a controller configured to:

controlling the wind speed sensor to acquire wind speed data of the wind generating set in real time;

controlling the vibration detection device to acquire vibration data of the wind generating set in real time;

controlling the comparator to determine whether the wind speed value is greater than or equal to a predetermined wind speed value and to determine whether the oscillation value is greater than or equal to a predetermined oscillation value;

when the wind speed value is greater than or equal to the preset wind speed value and the vibration value is greater than or equal to the preset vibration value, controlling the at least one pitch system actuating mechanism to adjust the pitch angle of the blades in the target wind sweeping area in the wind generating set according to the stress condition of the wind sweeping surface of the impeller of the wind generating set,

wherein the controller is further configured to adjust the pitch angle of the corresponding blade in the target wind sweeping area according to the magnitude relation of the wind power received by the upper side and the wind power received by the lower side of the wind sweeping surface of the impeller of the wind generating set.

16. A computer-readable storage medium storing a computer program which, when executed by a controller, implements the method of any one of claims 1 to 7.