Wind turbine blade dynamic balance monitoring and early warning method and system thereof

Abstract

The wind blade dynamic balance monitoring and early warning method of the wind driven generator provided by the application comprises the following steps: S1, any wind blade of the wind driven generator is set as a reference wind blade, a mass point of the reference wind blade is set as a reference point, and a coordinate system is established by taking any point of the axis of the rotating shaft of the wind driven generator as an origin; an included angle between a line connecting the position of the reference point at the starting moment of the set sampling period t and the origin of the coordinate system and a line connecting the position of the reference point at the end moment of the set sampling period and the origin is determined; the angular velocity of the reference wind blade is determined based on the included angle, and the centrifugal force of the reference wind blade is determined based on the angular velocity; the moment of the right side of the axis of the rotating shaft of the wind driven generator is determined based on the centrifugal force of the reference wind blade and the gravity of the reference wind blade; the moment of the left side of the axis of the rotating shaft of the wind driven generator is determined based on the angular velocity of the reference wind blade and the gravity of the other two wind blades; whether the absolute value of the difference between the moments of the left and right sides of the axis of the rotating shaft of the wind driven generator is greater than a set threshold value is judged, and if yes, the wind blades of the wind driven generator are dynamically unbalanced, and early warning is performed.

Description

Technical Field

[0001] This invention relates to the field of power equipment protection and early warning, and more particularly to a method and system for monitoring and early warning of dynamic balance of wind turbine blades. Background Technology

[0002] Wind power, as a green and clean energy source, is an important measure to reduce carbon emissions and achieve carbon compliance. The utilization and promotion of clean energy plays a vital role in sustainable economic development. However, wind power equipment is expensive, and during operation, extreme environments such as geological collapse, tilting, and blade icing can significantly affect the dynamic balance of the equipment. This can lead to eccentric rotation of the blade shaft and uneven stress. If the dynamic balance of the wind turbine blades is not monitored, prolonged eccentric rotation and uneven stress on the blade shaft will result in permanent damage to the wind turbine's transmission mechanism.

[0003] Although there are some existing methods or systems for monitoring the balance of wind turbines, the processes or structures of these existing technologies are relatively complex and not easy to apply. Moreover, the reliability of their monitoring and early warning is difficult to guarantee.

[0004] Therefore, in order to solve the above-mentioned technical problems, it is urgent to propose a new technical approach. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a method and system for monitoring and early warning of the dynamic balance of wind turbine blades, which can accurately and timely warn of the dynamic balance of wind turbine blades, thereby effectively preventing the wind turbine blades from being in a state of dynamic imbalance for a long time. Moreover, the entire monitoring process is simple and easy to use, and can be corrected in real time, thereby ensuring the accuracy and reliability of the monitoring results.

[0006] This invention provides a method for monitoring and early warning of dynamic balance of wind turbine blades, comprising the following steps:

[0007] S1. Set any one of the blades of the wind turbine as the reference blade, take the mass point of the reference blade as the reference point, and establish a coordinate system with any point on the axis of the wind turbine shaft as the origin, and the X-axis and Y-axis of the coordinate system are perpendicular to the axis of the wind turbine shaft.

[0008] S2. Determine the angle between the line connecting the position of the reference point at the beginning of the set sampling period t and the origin of the coordinate system, and the line connecting the position of the reference point at the end of the set sampling period and the origin of the coordinate system.

[0009] S3. Determine the angular velocity of the reference wind turbine blade based on the included angle, and determine the centrifugal force of the reference wind turbine blade based on the angular velocity;

[0010] S4. Determine the torque on the right side of the wind turbine shaft axis based on the centrifugal force and gravity of the reference wind turbine blade;

[0011] S5. Determine the torque on the left side of the wind turbine shaft axis based on the angular velocity of the reference blade and the gravity of the other two blades;

[0012] S6. Determine whether the absolute value of the difference between the torque on the left and right sides of the wind turbine shaft is greater than the set threshold. If so, the wind turbine blades are dynamically unbalanced, and an early warning is issued.

[0013] Furthermore, determining the angle between the line connecting the reference point at the start of the set sampling period t and the origin of the coordinate system, and the line connecting the reference point at the end of the set sampling period and the origin of the coordinate system, specifically includes:

[0014] Determine the coordinates of the reference point at the starting time of the set sampling period t. And the coordinates of the reference point at the end of the set sampling period t ;

[0015] Calculate the included angle :

[0016] .

[0017] Furthermore, the angular velocity of the reference wind turbine blade Calculated using the following formula:

[0018] .

[0019] Furthermore, the centrifugal force of the reference wind turbine blades Calculated using the following formula:

[0020] ;in, The total mass of the reference wind turbine blades, The distance from the reference blade's particle to the axis of rotation is denoted as .

[0021] Furthermore, the torque on the right side of the wind turbine's shaft axis is determined using the following formula. :

[0022] ;

[0023] ;

[0024] in, The weight of the reference wind turbine blades, The vertical component of the centrifugal force of the reference wind turbine blade. The horizontal distance between the center of mass of the reference wind turbine blade and the axis of rotation of the wind turbine generator. The angle between the center line of the centroid of the reference wind turbine blade and the positive half-axis of the X-axis of the coordinate system.

[0025] Furthermore, the torque on the left side of the wind turbine's shaft axis is determined using the following formula:

[0026] ;

[0027] in: The weight of the first non-reference blade of the wind turbine. This represents the vertical component of the centrifugal force of the first non-reference blade of the wind turbine. The horizontal distance between the center of mass of the first non-reference blade of the wind turbine and the axis of rotation of the wind turbine. The weight of the second non-reference blade of the wind turbine. This represents the vertical component of the centrifugal force of the second non-reference blade of the wind turbine. The horizontal distance between the center of mass of the second non-reference blade of the wind turbine and the axis of rotation of the wind turbine. and The calculation process and The calculation process is the same.

[0028] Accordingly, the present invention also provides an early warning system for the above-mentioned early warning method, including a gyroscope and a monitoring and early warning unit;

[0029] The gyroscope is set at the center of mass of the reference blade of the wind turbine, and the gyroscope is used to monitor the real-time coordinates of the center of mass of the reference blade and output them to the monitoring and early warning unit.

[0030] The monitoring and early warning unit is used to receive the real-time coordinates output by the gyroscope and execute steps S2-S6 based on the coordinates.

[0031] Furthermore, the detection and early warning unit includes a controller and an early warning module;

[0032] The controller is used to receive the real-time coordinates of the reference wind turbine blades output by the gyroscope, and to determine whether the wind turbine blades are dynamically balanced according to steps S2-S6. If not, it outputs a warning command.

[0033] The early warning module is used to receive early warning commands output by the controller and execute the early warning.

[0034] Furthermore, it also includes a position correction module, which includes magnetic elements and magnetic sensing devices;

[0035] The magnetic element is disposed on the reference blade and located at the center line of the reference blade's center of mass. The magnetic induction device is disposed on the shroud of the wind turbine, and when the reference blade rotates to a vertically upward position, the projection of the center line of the center of mass and the line connecting the magnetic induction device and the magnetic element on the axis of the wind turbine's rotating shaft coincides. The output end of the magnetic induction device is connected to the controller.

[0036] The beneficial effects of this invention are: it can accurately and promptly warn of the dynamic balance of wind turbine blades, thereby effectively preventing wind turbine blades from being in a state of dynamic imbalance for a long time. Moreover, the entire monitoring process is simple and convenient to use, and it can be corrected in real time, thereby ensuring the accuracy and reliability of the monitoring results. Attached Figure Description

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0038] Figure 1 This is a flowchart of the present invention.

[0039] Figure 2 This is a schematic diagram of the system structure of the present invention.

[0040] Figure 3 This is a schematic diagram of the installation of the position correction module of the present invention.

[0041] Figure 4 This is a schematic diagram illustrating the dynamic balance of gravity and centrifugal force of the wind turbine blades according to the present invention. Detailed Implementation

[0042] The present invention will be further described in detail below:

[0043] This invention provides a method for monitoring and early warning of dynamic balance of wind turbine blades, comprising the following steps:

[0044] S1. Set any one of the blades of the wind turbine as the reference blade, take the mass point of the reference blade as the reference point, and establish a coordinate system with any point on the axis of the wind turbine shaft as the origin, and the X-axis and Y-axis of the coordinate system are perpendicular to the axis of the wind turbine shaft.

[0045] S2. Determine the angle between the line connecting the reference point at the start time of the set sampling period t and the origin of the coordinate system, and the line connecting the reference point at the end time of the set sampling period and the origin of the coordinate system; of course, the sampling period t is a time series, and the end time of the current period is the start time of the next period (except for the first and last sampling periods).

[0046] S3. Determine the angular velocity of the reference wind turbine blade based on the included angle, and determine the centrifugal force of the reference wind turbine blade based on the angular velocity;

[0047] S4. Determine the torque on the right side of the wind turbine shaft axis based on the centrifugal force and gravity of the reference wind turbine blade;

[0048] S5. Determine the torque on the left side of the wind turbine shaft axis based on the angular velocity of the reference blade and the gravity of the other two blades;

[0049] S6. Determine if the absolute value of the difference between the torques on the left and right sides of the wind turbine shaft exceeds a set threshold. If so, the wind turbine blades are dynamically unbalanced, and an early warning is issued. This method accurately and promptly monitors the dynamic balance of the wind turbine blades, effectively preventing them from remaining in a state of dynamic imbalance for extended periods. The entire monitoring process is simple, convenient, and allows for real-time correction, ensuring the accuracy and reliability of the monitoring results.

[0050] In this embodiment, determining the angle between the line connecting the reference point at the start of the set sampling period t and the origin of the coordinate system, and the line connecting the reference point at the end of the set sampling period and the origin of the coordinate system, specifically includes:

[0051] Determine the coordinates of the reference point at the starting time of the set sampling period t. And the coordinates of the reference point at the end of the set sampling period t ;

[0052] Calculate the included angle :

[0053] (1).

[0054] Specifically, the angular velocity of the reference wind turbine blade Calculated using the following formula:

[0055] (2).

[0056] In this embodiment, the centrifugal force of the reference wind turbine blade Calculated using the following formula:

[0057] (3); among them, The total mass of the reference wind turbine blade includes the blade's own mass, as well as the mass of dust and icing that accumulates on the blade during service. The distance from the mass point of the reference wind turbine blade to the axis of rotation is the distance between the center of mass and the root of the wind turbine blade.

[0058] In this embodiment, the torque on the right side of the wind turbine shaft axis is determined by the following formula. :

[0059] (4);

[0060] (5);

[0061] in, The weight of the reference wind turbine blades, The vertical component of the centrifugal force of the reference wind turbine blade. The horizontal distance between the center of mass of the reference wind turbine blade and the axis of rotation of the wind turbine generator. The angle between the centerline of the centroid of the reference wind turbine blade and the positive x-axis of the coordinate system should be noted: The direction of gravity on the reference wind turbine blades is always vertically downwards. The vertical component of the centrifugal force of the reference blade is not necessarily the same; that is, these two quantities are a vector, possessing directionality, such as... Figure 4 As shown: When the reference wind turbine blades rotate to quadrants 1 and 4 of the coordinate system, and If the directions are the same, then the torque is calculated by adding the two forces. However, when the reference blades are in quadrants 2 and 4, then... and The direction is opposite, so when calculating, the "+" in the formula needs to be changed to "-". This is because the rotation of the fan blades is determined by the clockwise rotation. If the fan blades rotate counterclockwise, the situation is exactly the opposite. However, the calculation principle is the same.

[0062] In this embodiment, the torque on the left side of the wind turbine shaft axis is determined by the following formula:

[0063] (6);

[0064] in: The weight of the first non-reference blade of the wind turbine. This represents the vertical component of the centrifugal force of the first non-reference blade of the wind turbine. The horizontal distance between the center of mass of the first non-reference blade of the wind turbine and the axis of rotation of the wind turbine. The weight of the second non-reference blade of the wind turbine. This represents the vertical component of the centrifugal force of the second non-reference blade of the wind turbine. The horizontal distance between the center of mass of the second non-reference blade of the wind turbine and the axis of rotation of the wind turbine. and The calculation process and The calculation process is the same, that is to say: and The parameters and formula structure involved in the calculation process are similar to... They are all the same, but you should also pay attention when calculating the torque. and Directionality, and The criteria for calculation are the same. Since the angular velocity of the reference blade is the same as that of the other two non-reference blades, it is only necessary to determine the angular velocity of the reference blade. Then, when calculating the centrifugal force of the non-reference blades, the angular velocity of the reference blade can be substituted into the calculation. In addition, it should be noted that in the above calculations, the left and right torques are determined only by the position of the blades in the attached diagram. For example, when the non-reference blade 3 rotates to quadrant 1, and the reference blade 1 and the non-reference blade 3 are in quadrant 2, then the right torque is calculated using the parameters of the non-reference blade 3. The calculation formula is exactly the same as the formula for the right torque mentioned above. The left torque is calculated by the reference blade 1 and the non-reference blade 2 together. Other cases are calculated in the same way. Of course, there are also cases where there are two blades on the left side of the wind turbine shaft and only one blade on the right side. In this case, the torque is calculated according to the formula mentioned above, except that the left torque is the resultant torque of the two blades. That is to say, the right torque is calculated using formula (6), and the left torque is calculated using formula (4), except that the parameters are the parameters of the corresponding blades.

[0065] Accordingly, the present invention also provides an early warning system for the above-mentioned early warning method, including a gyroscope and a monitoring and early warning unit;

[0066] The gyroscope is set at the center of mass of the reference blade of the wind turbine, and the gyroscope is used to monitor the real-time coordinates of the center of mass of the reference blade and output them to the monitoring and early warning unit.

[0067] The monitoring and early warning unit is used to receive the real-time coordinates output by the gyroscope and execute steps S2-S6 based on the coordinates. The gyroscope is used to detect the position of the center of mass of the reference wind turbine blade, and the coordinates of the center of mass of the reference wind turbine blade are determined based on the position. The gyroscope used is an existing 3D gyroscope.

[0068] In this embodiment, the detection and early warning unit includes a controller and an early warning module;

[0069] The controller is used to receive the real-time coordinates of the reference wind turbine blades output by the gyroscope, and to determine whether the wind turbine blades are dynamically balanced according to steps S2-S6. If not, it outputs a warning command.

[0070] The warning module is used to receive and execute warning commands output by the controller. The warning module adopts existing audible and visual alarms, displays, or combinations thereof, and the controller adopts existing PCs, microcontrollers, etc.

[0071] In this embodiment, a position correction module is also included, which includes a magnetic element and a magnetic sensing device;

[0072] The magnetic element is mounted on the reference blade and located at its center of mass. The magnetic induction device is mounted on the wind turbine's housing. When the reference blade rotates to a vertically upward position, the projections of the center of mass and the line connecting the magnetic induction device and the magnetic element onto the wind turbine's shaft axis coincide. The output of the magnetic induction device is connected to a controller. In other words, during the rotation of the reference blade, once the projections of the center of mass and the line connecting the magnetic induction device and the magnetic element onto the wind turbine's shaft axis coincide, the position of the reference blade's center of mass at that moment is used as the new reference position. This avoids errors that may occur with gyroscopes during long-term service and ensures the accuracy of the final monitoring results. The magnetic element can be a readily available permanent magnet, and the magnetic induction device can be a readily available Hall effect magnetic induction sensor.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for monitoring and early warning of dynamic balance of wind turbine blades, characterized in that: Includes the following steps: S1. Set any one of the blades of the wind turbine as the reference blade, take the mass point of the reference blade as the reference point, and establish a coordinate system with any point on the axis of the wind turbine shaft as the origin, and the X-axis and Y-axis of the coordinate system are perpendicular to the axis of the wind turbine shaft. S2. Determine the angle between the line connecting the reference point at the start of the set sampling period t and the origin of the coordinate system, and the line connecting the reference point at the end of the set sampling period and the origin of the coordinate system; specifically: Determine the coordinates of the reference point at the starting time of the set sampling period t. And the coordinates of the reference point at the end of the set sampling period t ; Calculate the included angle : ； S3. Determine the angular velocity of the reference wind turbine blade based on the included angle, and determine the centrifugal force of the reference wind turbine blade based on the angular velocity; angular velocity of the reference wind turbine blade Calculated using the following formula: ； Centrifugal force of the reference fan blade Calculated using the following formula: ;in, The total mass of the reference wind turbine blades, The distance from the reference blade's particle to the axis of rotation; S4. Determine the torque on the right side of the wind turbine shaft axis based on the centrifugal force and gravity of the reference wind turbine blade; specifically: The torque on the right side of the wind turbine shaft axis is determined by the following formula. : ； ； in, The weight of the reference wind turbine blades, The vertical component of the centrifugal force of the reference wind turbine blade. The horizontal distance between the center of mass of the reference wind turbine blade and the axis of rotation of the wind turbine generator. The angle between the center line of the centroid of the reference wind turbine blade and the positive half-axis of the X-axis of the coordinate system; S5. Determine the torque on the left side of the wind turbine shaft axis based on the angular velocity of the reference blade and the gravity of the other two blades; The torque on the left side of the wind turbine's shaft axis is determined using the following formula: ； in: The weight of the first non-reference blade of the wind turbine. This represents the vertical component of the centrifugal force of the first non-reference blade of the wind turbine. The horizontal distance between the center of mass of the first non-reference blade of the wind turbine and the axis of rotation of the wind turbine. The weight of the second non-reference blade of the wind turbine. This represents the vertical component of the centrifugal force of the second non-reference blade of the wind turbine. The horizontal distance between the center of mass of the second non-reference blade of the wind turbine and the axis of rotation of the wind turbine. and The calculation process and The calculation process is the same; S6. Determine whether the absolute value of the difference between the torque on the left and right sides of the wind turbine shaft is greater than the set threshold. If so, the wind turbine blades are dynamically unbalanced, and an early warning is issued.

2. An early warning system based on the early warning method of claim 1, characterized in that: Includes gyroscopes and monitoring and early warning units; The gyroscope is installed at the center of mass of the reference blade of the wind turbine, and the gyroscope is used to monitor the real-time coordinates of the center of mass of the reference blade and output them to the monitoring and early warning unit. The monitoring and early warning unit is used to receive the real-time coordinates output by the gyroscope and execute steps S2-S6 based on the coordinates.

3. The early warning system according to claim 2, characterized in that: The monitoring and early warning unit includes a controller and an early warning module; The controller is used to receive the real-time coordinates of the reference wind turbine blades output by the gyroscope, and to determine whether the wind turbine blades are dynamically balanced according to steps S2-S6. If not, it outputs an early warning command. The early warning module is used to receive early warning commands output by the controller and execute the early warning.

4. The early warning system according to claim 3, characterized in that: It also includes a position correction module, which includes magnetic elements and magnetic sensing devices; The magnetic element is disposed on the reference blade and located at the center line of the reference blade's center of mass. The magnetic induction device is disposed on the shroud of the wind turbine, and when the reference blade rotates to a vertically upward position, the projection of the center line of the center of mass and the line connecting the magnetic induction device and the magnetic element on the axis of the wind turbine's rotating shaft coincides. The output end of the magnetic induction device is connected to the controller.

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