A wind turbine tower clearance estimation method and system

Abstract

The present invention discloses a method and system for estimating the tower clearance of a wind turbine generator set, which belongs to the field of wind power generation, and includes: calculating the deformation of blades and towers of a wind turbine generator set; selecting multiple blade sections according to the blade deformation, and performing grid refinement processing on the blade sections to obtain the coordinates of each blade section after refinement; performing grid refinement processing on the tower section, selecting the tower section at the blade tip height, and obtaining the coordinates of the maximum windward radius of the tower section; calculating the distance measurement of each blade section according to the coordinates of each blade section, and calculating the tower clearance value according to the coordinates of the maximum windward radius of the tower section; selecting multiple groups of blade section distance measurement that meet the set requirements, and obtaining the relationship between the blade section distance measurement and the tower clearance value by fitting. The present invention takes into account the deformation of blades and towers, and the tower clearance can be deduced by measuring only a certain section of the blade, and has the advantages of simple measurement, strong reliability, and low hardware cost.

Description

Technical Field

[0001] The present invention relates to the field of wind power generation, and in particular to a method and system for estimating the clearance of a tower of a wind power generator set. Background Art

[0002] At present, the main method for monitoring the tower clearance of wind turbines is direct measurement, which uses sensors to directly measure the distance between the blade tip and the tower. There are two main measurement schemes:

[0003] (1) Use laser sensors to measure tower clearance. There are generally two methods: a) One is to measure the distance between the blade and the sensor, and calculate the tower clearance through trigonometric conversion. This method ignores the deformation of the blade and the tower, and the calculation method is inaccurate. At the same time, this method requires the laser beam to hit the tip of the blade to measure the tower clearance, which is difficult to measure and difficult to ensure measurement accuracy; b) The other is to use multiple laser beams to measure the blade and the tower at the same time, and calculate the tower clearance value through coordinates. This method takes into account the deformation of the blade and the tower, and can directly measure the tower clearance value. However, since it is necessary to measure the deformation of the blade and the tower at the same time, multiple laser beams need to be irradiated at the same time to ensure that the beam can cover the tip of the blade. The hardware cost is high and the calculation is more complicated.

[0004] (2) Use visual sensors to measure tower clearance. This method uses a visual recognition algorithm to extract the blade tip profile and calculate the distance between the blade tip and the tower. This method is greatly affected by the external environment. The recognition effect is poor in weather such as dust, fog, and at night. It also has problems such as high hardware cost, complex algorithm, and poor reliability. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method and system for estimating the tower clearance of a wind turbine generator set, which takes into account the deformation of blades and towers. At the same time, it does not require sensors to strictly measure the distance at the tip of the blades. The tower clearance can be inferred by measuring a certain cross-section of the blade. It has the advantages of simple measurement, high reliability, and low hardware cost.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a method for estimating a tower clearance of a wind turbine generator set, comprising:

[0008] Calculate the deformation of wind turbine blades and towers;

[0009] Select multiple blade sections according to the blade deformation, and perform mesh refinement on the blade sections to obtain the refined coordinates of each blade section;

[0010] Perform mesh refinement on the tower section, select the tower section at the blade tip height, and obtain the coordinates of the maximum radius of the windward surface of the tower section;

[0011] Calculate the distance measurement of each blade section according to the coordinates of each blade section, and calculate the tower clearance value according to the coordinates of the maximum radius of the windward surface of the tower section;

[0012] Multiple groups of blade section distance measurements that meet the set requirements are selected, and the relationship between the blade section distance measurement and the tower clearance value is obtained by fitting.

[0013] As a further implementation manner, the blade cross-section distance measurement is the distance between the blade cross-section and a distance measurement sensor.

[0014] As a further implementation, the distance measuring sensor is installed at the bottom or outside of the cabin.

[0015] As a further implementation method, a three-dimensional coordinate system of the wind turbine generator set is established with the center of the tower base as the coordinate origin to determine the coordinates of the distance measuring sensor.

[0016] As a further implementation method, according to the measurement installation angle of the distance measuring sensor, the blade section distance measurement and tower clearance value that meet the requirements are selected.

[0017] As a further implementation, the blade cross-section distance measurement satisfies the following conditions:

[0018] The ratio of the distance between the blade section to be measured and the longitudinal section of the distance measuring sensor installation position to the distance measurement of the blade section is equal to the sine value of the installation angle.

[0019] As a further implementation method, multiple groups of blade section distance measurements and tower clearance values ​​constitute a data group, and a scatter plot of blade section distance measurements and tower clearance values ​​is obtained through the data group.

[0020] As a further implementation method, obviously abnormal discrete points are eliminated, and a corresponding fitting method is selected according to the distribution of the data group.

[0021] As a further implementation method, the operating conditions of the wind turbine generator set under different power limit conditions are set according to the set standards, and the deformation of the blades and the tower are calculated by simulation software.

[0022] In a second aspect, an embodiment of the present invention further provides a wind turbine tower clearance estimation system, comprising:

[0023] A deformation calculation unit is used to calculate the deformation of the blades and tower of the wind turbine generator set;

[0024] A blade section coordinate acquisition unit is used to select multiple blade sections according to the blade deformation, and perform mesh refinement processing on the blade sections to obtain the refined coordinates of each blade section;

[0025] A tower section windward surface coordinate acquisition unit is used to perform grid refinement processing on the tower section, select the tower section at the blade tip height, and obtain the coordinates of the maximum radius of the tower section windward surface;

[0026] A blade section distance calculation unit, used to calculate the distance of each blade section according to the coordinates of each blade section;

[0027] A tower clearance value calculation unit calculates the tower clearance value according to the coordinates of the maximum radius of the windward surface of the tower section;

[0028] The fitting relationship acquisition unit is used to select multiple groups of blade section distance measurements that meet the set requirements, and obtain the relationship between the blade section distance measurements and the tower clearance value through fitting.

[0029] The beneficial effects of the present invention are as follows:

[0030] (1) The present invention does not need to measure the distance between the blade tip and the tower, but only needs to measure the distance between a certain blade section and the distance measuring sensor to calculate the tower clearance. Compared with the point measurement method of the prior art, the tower clearance measurement process is simplified, the difficulty of obtaining the clearance is greatly reduced, and the reliability of the tower clearance value is increased.

[0031] (2) The present invention converts the measurement of tower clearance into the distance from the distance measuring sensor to the blade cross section. The tower clearance is calculated by the blade cross section, taking into account the deformation of the blade and the tower, and the calculation result is more accurate.

[0032] (3) The present invention only requires the installation of a distance measuring sensor to accurately measure the tower clearance, with low hardware cost and simple and reliable installation and implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 is a flow chart of the present invention according to one or more embodiments;

[0035] Figure 2 is a schematic diagram of blade section selection of Bladed simulation software according to one or more embodiments;

[0036] Figure 3 is a schematic diagram of a three-dimensional coordinate system of a wind turbine generator set according to one or more embodiments;

[0037] Figure 4 is a schematic diagram of installation angles of a ranging sensor according to one or more embodiments;

[0038] Figure 5 is a schematic diagram comparing estimated headroom to measured headroom according to one or more embodiments.

[0039] Among them, 1. tower, 2. blades, 3. ranging sensor. DETAILED DESCRIPTION

[0040] Embodiment 1:

[0041] This embodiment provides a method for estimating the clearance of a wind turbine tower. Figure 1 As shown, including:

[0042] Calculate the deformation of wind turbine blades and towers;

[0043] Select multiple blade sections according to the blade deformation, and perform mesh refinement on the blade sections to obtain the refined coordinates of each blade section;

[0044] Perform mesh refinement on the tower section, select the tower section at the blade tip height, and obtain the coordinates of the maximum radius of the windward surface of the tower section;

[0045] Calculate the distance measurement of each blade section according to the coordinates of each blade section, and calculate the tower clearance value according to the coordinates of the maximum radius of the windward surface of the tower section;

[0046] Multiple groups of blade section distance measurements that meet the set requirements are selected, and the relationship between the blade section distance measurement and the tower clearance value is obtained by fitting.

[0047] Specifically, the steps include:

[0048] Step 1: Calculate the deformation of the wind turbine blades and tower 1. In order to fully reflect the deformation of the tower and blades of the wind turbine under different working conditions, the operating conditions of the unit under different power limits are set according to the IEC standard, and simulation calculations can be performed through wind power industry simulation software such as Bladed and Fast.

[0049] Taking a certain model of 2.5MW unit as an example, the Bladed4.9 version simulation software is selected, the operating condition is set according to the IEC61400-1 third edition standard, and the turbulence intensity is set according to C. The dlc1.2 operating condition setting is shown in Table 1.

[0050] Table 1 DLC1.2 working condition setting table

[0051]

[0052]

[0053] In order to accurately simulate the deformation of tower 1 and blade 2, as many blade and tower sections as possible should be selected during the simulation calculation. Taking the simulation software Bladed4.9 as an example, select all blade sections such as Figure 2 shown.

[0054] Step 2: Obtain the data set of blade section distance measurement and tower clearance, including the following:

[0055] (1) Establish a three-dimensional coordinate system for the wind turbine generator set, such as Figure 3 As shown, the center of the tower base is the coordinate origin.

[0056] (2) Determine the position of the ranging sensor at the bottom of the cabin, with coordinates (Xd, Yd, Zd).

[0057] (3) Refine the mesh of the blade section to obtain the refined blade section coordinates (X i ,Y i ,Z i )(i=1,2,3,…,n), where n is the number of blade sections after refinement, i is the serial number of the blade section, the larger the value is, the closer it is to the blade tip, (X n ,Y n ,Z n ) represents the coordinates at the blade tip.

[0058] (4) Refine the grid of the tower section. Select the tower section at the blade tip height. At this time, the coordinate of the maximum radius of the windward surface of the tower section is (XT n ,YT n ,Z n ).

[0059] (5) Calculate the distance from each blade section to the ranging sensor and the tower clearance value.

[0060]

[0061]

[0062] Among them, D i represents the distance between the i-th blade section and the ranging sensor, and Tip is the tower clearance value.

[0063] (6) Select the required distance measurement clearance data set.

[0064] The blade section distance measurement meets the following conditions:

[0065] The ratio of the distance between the blade section to be measured and the longitudinal section of the distance sensor installation position and the distance measurement of the blade section is equal to the sine value of the installation angle, that is:

[0066] like Figure 4As shown, it is assumed that the angle between the line connecting the distance measuring sensor 3 and the blade section to be measured and the parallel plane of the tower is β.

[0067] The required blade distance measurement should satisfy the following formula.

[0068]

[0069] Select the blade section distance that meets the requirements and record it as Dc, and get the data set of blade distance and tower clearance (Dc, Tip)

[0070] Step 3: Obtain the relationship between blade section distance measurement and tower clearance. From step 2, multiple sets of distance measurement and tower clearance data can be obtained, and a scatter plot of distance measurement and clearance can be drawn. Obviously abnormal discrete points can be removed, and an appropriate fitting method can be selected according to the distribution of the data. Commonly used fitting methods include linear fitting, polynomial fitting, exponential fitting, and Gaussian fitting.

[0071] In order to ensure the accuracy of the ranging calculation and the availability of the data, this embodiment performs grid refinement interpolation on the blades and towers, divides the calculation sections of the blades and towers into centimeters, millimeters or even lower levels according to data requirements, and then performs ranging between each calculation section and the ranging sensor.

[0072] Taking a certain model of 2.5MW unit as an example, a scatter plot of blade section distance measurement and tower clearance is drawn. After removing the obviously abnormal data points, a second-order polynomial is used to fit the remaining data. After obtaining the fitting formula through simulation calculation, the tower clearance can be converted into the distance between the blade section and the distance sensor, which greatly simplifies the clearance measurement method.

[0073] In order to verify the reliability of the clearance estimation method, a test unit was selected to install a multi-beam lidar to directly measure the tower clearance for comparison with the estimated clearance. The comparison results are shown in Figure 2. Figure 5 As shown in the figure, it can be seen from the comparison results that the tower clearance estimation method is more reliable.

[0074] Embodiment 2:

[0075] This embodiment provides a wind turbine tower clearance estimation system, including:

[0076] A deformation calculation unit is used to calculate the deformation of the blades and tower of the wind turbine generator set;

[0077] A blade section coordinate acquisition unit is used to select multiple blade sections according to the blade deformation, and perform mesh refinement processing on the blade sections to obtain the refined coordinates of each blade section;

[0078] A tower section windward surface coordinate acquisition unit is used to perform grid refinement processing on the tower section, select the tower section at the blade tip height, and obtain the coordinates of the maximum radius of the tower section windward surface;

[0079] A blade section distance calculation unit, used to calculate the distance of each blade section according to the coordinates of each blade section;

[0080] A tower clearance value calculation unit calculates the tower clearance value according to the coordinates of the maximum radius of the windward surface of the tower section;

[0081] The fitting relationship acquisition unit is used to select multiple groups of blade section distance measurements that meet the set requirements, and obtain the relationship between the blade section distance measurements and the tower clearance value through fitting.

[0082] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for estimating the clearance of a wind turbine tower, characterized in that: include: Calculate the deformation of wind turbine blades and towers; Select multiple blade sections according to the blade deformation, and perform mesh refinement on the blade sections to obtain the refined coordinates of each blade section; Perform mesh refinement on the tower section, select the tower section at the blade tip height, and obtain the coordinates of the maximum radius of the windward surface of the tower section; Calculate the distance measurement of each blade section according to the coordinates of each blade section, and calculate the tower clearance value according to the coordinates of the maximum radius of the windward surface of the tower section; Select multiple groups of blade section distance measurements that meet the set requirements, and obtain the relationship between the blade section distance measurement and the tower clearance value through fitting; The blade cross-section distance measurement is the distance between the blade cross-section and the distance measurement sensor; Calculate the distance from each blade section to the distance sensor and the tower clearance value, specifically: in, represents the distance between the i-th blade section and the ranging sensor, Tip is the tower clearance value, (X i ,Y i ,Z i ) is the coordinate of the blade section after refinement (i=1,2,3,…,n), where n is the number of blade sections after refinement, i is the serial number of the blade section, (X n ,Y n ,Z n ) represents the coordinates at the blade tip, (XT n ,YT n ,Z n ) is the coordinate of the maximum radius of the windward surface of the tower section, (Xd, Yd, Zd) is the position coordinate of the ranging sensor at the bottom of the cabin; The blade cross-section distance measurement meets the following conditions: The ratio of the distance between the blade section to be measured and the longitudinal section of the distance measuring sensor installation position to the distance measurement of the blade section is equal to the sine value of the installation angle.

2. A wind turbine tower clearance estimation method according to claim 1, characterized in that: The distance measuring sensor is installed at the bottom or outside of the cabin.

3. A wind turbine tower clearance estimation method according to claim 1 or 2, characterized in that: A three-dimensional coordinate system of the wind turbine generator set is established with the center of the tower base as the coordinate origin to determine the coordinates of the ranging sensor.

4. A wind turbine tower clearance estimation method according to claim 1 or 2, characterized in that: According to the measurement installation angle of the distance measuring sensor, select the blade section distance measurement and tower clearance value that meet the requirements.

5. A wind turbine tower clearance estimation method according to claim 1, characterized in that: A plurality of groups of blade section distance measurements and tower clearance values ​​constitute a data group, and a scatter plot of the blade section distance measurements and the tower clearance values ​​is obtained through the data group.

6. A wind turbine tower clearance estimation method according to claim 5, characterized in that: Remove obviously abnormal discrete points and select the corresponding fitting method according to the distribution of the data group.

7. A wind turbine tower clearance estimation method according to claim 1, characterized in that: The operating conditions of the wind turbine under different power limit conditions are set according to the set standards, and the deformation of the blades and tower are calculated through simulation software.

8. A wind turbine tower clearance estimation system, characterized in that: include: A deformation calculation unit is used to calculate the deformation of the blades and tower of the wind turbine generator set; A blade section coordinate acquisition unit is used to select multiple blade sections according to the blade deformation, and perform mesh refinement processing on the blade sections to obtain the refined coordinates of each blade section; A tower section windward surface coordinate acquisition unit is used to perform grid refinement processing on the tower section, select the tower section at the blade tip height, and obtain the coordinates of the maximum radius of the tower section windward surface; A blade section distance calculation unit, used to calculate the distance of each blade section according to the coordinates of each blade section; A tower clearance value calculation unit calculates the tower clearance value according to the coordinates of the maximum radius of the windward surface of the tower section; A fitting relationship acquisition unit is used to select multiple groups of blade section distance measurements that meet the set requirements, and obtain the relationship between the blade section distance measurements and the tower clearance value through fitting; The blade cross-section distance measurement is the distance between the blade cross-section and the distance measurement sensor; Calculate the distance from each blade section to the distance sensor and the tower clearance value, specifically: in, represents the distance between the i-th blade section and the ranging sensor, Tip is the tower clearance value, (X i ,Y i ,Z i ) is the coordinate of the blade section after refinement (i=1,2,3,…,n), where n is the number of blade sections after refinement, i is the serial number of the blade section, (X n ,Y n ,Z n ) represents the coordinates at the blade tip, (XT n ,YT n ,Z n ) is the coordinate of the maximum radius of the windward surface of the tower section, (Xd, Yd, Zd) is the position coordinate of the ranging sensor at the bottom of the cabin; The blade cross-section distance measurement meets the following conditions: The ratio of the distance between the blade section to be measured and the longitudinal section of the distance measuring sensor installation position to the distance measurement of the blade section is equal to the sine value of the installation angle.

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