A wind turbine tower clearance control method and system based on nacelle inclination angle

Abstract

The present invention discloses a wind turbine tower clearance control method and system based on the cabin inclination angle, including: 1) obtaining the effective cabin inclination angle; 2) calculating the current wind rotor effective thrust according to the effective cabin inclination angle; 3) judging whether the current working condition has a tower clearance risk according to the currently calculated wind rotor effective thrust; 4) when the unit enters the tower clearance risk area, in the dangerous sector where the blade approaches the tower, the sector minimum blade angle is set, the pitch control command output by the pitch controller is compared with the sector minimum blade angle, and the larger angle is selected as the final pitch control command; when the unit does not have a tower clearance risk, the final pitch control command is the pitch control command output by the pitch control controller. The present invention can effectively control the tower clearance in a safe area, and the overall control cost is low and the reliability is high.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine control, and in particular to a method, system, storage medium and computing device for controlling a wind turbine tower clearance based on a nacelle inclination angle. Background Art

[0002] As a green and clean energy, wind power generation is widely and rapidly promoted around the world. With the continuous innovation of wind power technology, wind turbines are gradually developing towards large megawatts, high towers, and long blades. In addition, the withdrawal of electricity price subsidies for onshore and offshore wind power, and the grid parity of sea and land wind power have led to a continuous reduction in the cost of wind turbines. Therefore, in the era of wind power parity, new technologies and methods must be adopted to achieve lightweight design, ultra-long flexible blade design, and ultra-high flexible tower design of large megawatt wind turbines. Ultra-long flexible blades and ultra-high flexible towers will inevitably lead to insufficient clearance between blades and towers, increasing the risk of serious accidents such as blade sweeping towers. In terms of structural design, increasing the tower clearance by increasing the main shaft inclination, increasing the wind wheel cone angle, and adjusting the blade pre-bending will increase the cost and load of the whole machine, and the adjustment range is limited due to the limitations of production and manufacturing. In terms of control, laser radar can be used to measure blade deformation to achieve tower clearance control. However, laser radar is easily affected by rain, snow, haze, etc., has low reliability, and is expensive and is not conducive to mass application. Summary of the invention

[0003] The first purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and provide a wind turbine tower clearance control method based on the nacelle inclination angle, which can effectively control the tower clearance in a safe area with low overall control cost and high reliability.

[0004] A second object of the present invention is to provide a wind turbine tower clearance control system based on the nacelle inclination angle.

[0005] A third object of the present invention is to provide a storage medium.

[0006] A fourth object of the present invention is to provide a computing device.

[0007] The first object of the present invention is achieved by the following technical solution: A wind turbine tower clearance control method based on the nacelle inclination angle, performing the following operations:

[0008] 1) Collect the cabin inclination angle and process the data to obtain the effective cabin inclination angle;

[0009] 2) According to the effective inclination angle of the nacelle, the tower dynamic equation is established and the current effective thrust of the wind rotor is calculated;

[0010] 3) According to the currently calculated effective thrust of the wind rotor, determine whether there is a tower clearance risk in the current working condition. If there is a tower clearance risk, execute step 4), otherwise jump back to step 1);

[0011] 4) When the unit enters the tower clearance risk area, the minimum blade angle of the sector is set in the dangerous sector where the blades are close to the tower. At this time, the pitch command output by the pitch controller must be compared with the minimum blade angle of the sector, and the larger angle is selected as the final pitch command to control the tower clearance in a safe area; when the unit does not have a tower clearance risk, the pitch command output by the pitch controller does not need to be compared with the minimum blade angle of the sector, and the final pitch command is the pitch command output by the pitch controller.

[0012] Further, in step 1), the inclination of the nacelle is collected by an inclination sensor, which is installed in the nacelle of the wind turbine and moves together with the nacelle platform to collect the inclination of the nacelle main axis in real time; one or more inclination sensors can be installed in the nacelle, and redundant inclination sensors can increase the reliability of the nacelle inclination measurement; if multiple inclination sensors are used, the multiple inclination measurement values ​​can be combined in a weighted manner to obtain the nacelle inclination, and the specific formula is as follows:

[0013]

[0014] In the above formula, represents the average inclination angle of the cabin; θ 1 represents the measured inclination of the inclination sensor 1; η 1 Represents the weighting coefficient of the tilt sensor 1; θ 2 represents the measured inclination of the inclination sensor 2; η 2 represents the weighting coefficient of the tilt sensor 2; θ n represents the measured inclination angle of the inclination sensor n; η n Represents the weighting coefficient of the tilt sensor n; weighting coefficient η 1 , η 2 to η n The value range is between 0 and 1. The sensor with high precision selects a large weighting coefficient and satisfies the sum of the weighting coefficients η 1 +η 2 +…+η n is equal to 1;

[0015] In order to avoid the interference of high-frequency noise, transmission chain frequency and 3P frequency on the measured data, the average inclination angle of the nacelle is filtered as necessary. The filter includes a second-order low-pass filter and a band-stop filter. The components above the first-order frequency of the tower in the nacelle inclination angle data are attenuated. The effective inclination angle of the nacelle after filtering is expressed as follows:

[0016]

[0017] In the above formula, θ F represents the effective tilt angle of the cabin; F(s) represents the cabin tilt angle filter.

[0018] Further, in step 2), the tower dynamic equation is established, and the specific formula is as follows:

[0019]

[0020] In the above formula, F fa represents the effective thrust of the wind rotor; M represents the equivalent inertia of the tower; represents the second-order derivative of the effective inclination angle of the nacelle; D represents the equivalent damping of the tower; represents the first-order derivative of the effective inclination angle of the nacelle; K represents the equivalent stiffness of the tower; θ F Indicates the effective inclination angle of the cabin.

[0021] Furthermore, the specific values ​​of the tower equivalent inertia M, the tower equivalent damping D and the tower equivalent stiffness K are determined by setting the input step wind in the unit design software Bladed, simulating the change curve of the output wind rotor effective thrust and the effective inclination angle of the nacelle, and obtaining the tower equivalent inertia, tower equivalent damping and tower equivalent stiffness through the least quadratic fitting method.

[0022] Further, in step 3), due to wind turbulence, tower movement and pitch dynamic effects, the effective thrust of the wind rotor is actually distributed near the steady-state curve of the effective thrust of the wind rotor versus wind speed; the steady-state curve of the effective thrust of the wind rotor versus wind speed includes a section from the cut-in wind speed to the rated wind speed and a section from the rated wind speed to the cut-out wind speed; in the section from the cut-in wind speed to the rated wind speed, the effective thrust of the wind rotor increases with the increase of the average wind speed; in the section from the rated wind speed to the cut-out wind speed, the effective thrust of the wind rotor decreases with the increase of the average wind speed; at the rated wind speed point, the effective thrust of the wind rotor reaches a maximum value;

[0023] Therefore, the tower clearance risk area is defined as the interval near the rated wind speed, and this area is defined as the AB area, and the effective thrust of the wind rotor is greater than the rated wind speed point; since the wind speed measurement is affected by the wake and the wind rotor shielding, the data accuracy is low, so the boundary of the tower clearance risk area does not need to be judged by wind speed. The left boundary point A of the tower clearance risk area is judged according to the generator power at point A, and the right boundary point B of the tower clearance risk area is judged according to the pitch angle at point B; the judgment conditions for defining the tower clearance risk area are as follows:

[0024]

[0025] In the above formula, S f Indicates the tower clearance risk flag, 0 is not in the clearance risk area, 1 is in the clearance risk area; P gen Indicates the measured value of generator power; P Arepresents the power threshold of the clearance risk area; β represents the average pitch angle of the three blades; β B Indicates the pitch angle threshold in the clearance risk area; F fa Indicates the effective thrust of the wind wheel; F D Indicates the thrust threshold of the clearance risk area; if indicates the following judgment condition; & indicates logical AND operation; else indicates other situations.

[0026] Further, in step 4), the sector near the tower is defined as a dangerous sector. When the unit is in the tower clearance risk area and the blade enters the dangerous sector, the minimum blade angle of the blade in the dangerous sector is set to achieve the purpose of controlling the clearance within a safe range.

[0027] An azimuth sensor is installed in the hub of the wind rotor. When the wind rotor rotates, the azimuth of each blade can be measured in real time. The minimum blade angle of the sector is defined as follows:

[0028]

[0029] In the above formula, β 1，min represents the minimum blade angle of the sector of blade 1; represents the azimuth angle of blade 1; β 2，min represents the minimum blade angle of the sector of blade 2; represents the azimuth angle of blade 2; β 3，min represents the minimum blade angle of the sector of blade 3; represents the azimuth angle of blade 3; Represents the minimum blade angle lookup function of the sector;

[0030] When the unit is in the tower clearance risk area, the tower clearance risk flag is S f =1. At this time, the pitch control output of each blade pitch command should be compared with the minimum blade angle of each sector, and the larger angle should be selected as the final pitch command. The specific formula is as follows:

[0031]

[0032] In the above formula, β 1 set represents the final pitch command of blade 1; represents the final pitch command of blade 2; represents the final pitch command of blade 3; β 1 c Indicates the blade 1 pitch control command output by the pitch control controller; Indicates the blade 2 pitch control command output by the pitch control controller; represents the pitch command of blade 3 output by the pitch controller; β 1，minrepresents the minimum blade angle of blade 1; β 2，min represents the minimum blade angle of blade 2; β 3，min Indicates the minimum blade angle of blade 3; max{} indicates the maximum value;

[0033] If the tower clearance risk flag is S f is equal to 0. At this time, there is no tower clearance risk. The pitch command output by the pitch controller does not need to be compared with the minimum blade angle of the sector. The final pitch command is the pitch command output by the pitch controller.

[0034] The second object of the present invention is achieved by the following technical solution: a modular control system for wind turbines based on optimal control, used to implement the above-mentioned wind turbine tower clearance control method based on nacelle inclination, comprising:

[0035] The cabin inclination angle measurement module is used to collect the cabin inclination angle and perform data processing to obtain the cabin effective inclination angle;

[0036] The wind rotor thrust calculation module is used to establish the tower dynamics equation according to the effective inclination angle of the nacelle and calculate the current wind rotor effective thrust;

[0037] The tower clearance warning module is used to determine whether there is a tower clearance risk in the current working condition based on the currently calculated effective thrust of the wind rotor;

[0038] The sector pitch control module is used to set the sector minimum blade angle and actively increase the tower clearance. When the unit enters the tower clearance risk area and is in the dangerous sector where the blades are close to the tower, the pitch command output by the pitch controller is compared with the sector minimum blade angle, and the larger angle is selected as the final pitch command to control the tower clearance in a safe area. When the unit does not have a tower clearance risk, the pitch command output by the pitch controller does not need to be compared with the sector minimum blade angle, and the final pitch command is the pitch command output by the pitch controller.

[0039] The third object of the present invention is achieved through the following technical solution: a storage medium stores a program, and when the program is executed by a processor, the above-mentioned wind turbine tower clearance control method based on the nacelle inclination angle is implemented.

[0040] The fourth purpose of the present invention is achieved through the following technical solution: a computing device, comprising a processor and a memory for storing a program executable by the processor, wherein when the processor executes the program stored in the memory, the above-mentioned wind turbine tower clearance control method based on the nacelle inclination angle is implemented.

[0041] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0042] 1. The tower clearance control method proposed in the present invention adopts an inclination sensor to measure the inclination of the nacelle. The inclination sensor has low cost and mature products, and can be easily implemented as a standard feature in offshore aircraft.

[0043] 2. The solution of the present invention adopts the cabin inclination angle to reversely calculate the wind rotor thrust, and constructs a method for identifying the tower clearance risk area through power, pitch angle and effective wind rotor thrust.

[0044] 3. The scheme of the present invention proposes a method for controlling the minimum blade angle in a sector, defines the dangerous sector of the blade, and only when the blade enters the dangerous sector will the minimum blade angle be limited, so as to control the tower clearance within a safe range and minimize the influence of pitch change on power and speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is the steady-state curve of the effective thrust of the wind rotor versus wind speed.

[0046] Figure 2 Schematic diagram of blade azimuth angle and dangerous sector.

[0047] Figure 3 Schematic diagram of the minimum blade angle of the sector of three blades.

[0048] Figure 4 Schematic diagram of the system of the present invention. DETAILED DESCRIPTION

[0049] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0050] Example 1

[0051] This embodiment discloses a wind turbine tower clearance control method based on the nacelle inclination angle, and performs the following operations:

[0052] 1) The cabin inclination angle is collected by the inclination sensor and the data is processed to obtain the effective inclination angle of the cabin.

[0053] The inclination sensor is installed in the nacelle of the wind turbine and moves together with the nacelle platform to collect the inclination of the nacelle main axis in real time. One or more inclination sensors can be installed in the nacelle. Redundant inclination sensors can increase the reliability of nacelle inclination measurement. If multiple inclination sensors are used, multiple inclination measurement values ​​can be combined to obtain the nacelle inclination in a weighted manner. The specific formula is as follows:

[0054]

[0055] In the above formula, represents the average inclination angle of the cabin; θ 1 represents the measured inclination of the inclination sensor 1; η1 Represents the weighting coefficient of the tilt sensor 1; θ 2 represents the measured inclination of the inclination sensor 2; η 2 represents the weighting coefficient of the tilt sensor 2; θ n represents the measured inclination angle of the inclination sensor n; η n Represents the weighting coefficient of the tilt sensor n; weighting coefficient η 1 , η 2 to η n The value range is between 0 and 1. The sensor with high precision selects a large weighting coefficient and satisfies the sum of the weighting coefficients η 1 +η 2 +…+η n is equal to 1;

[0056] In order to avoid the interference of high-frequency noise, transmission chain frequency and 3P frequency on the measured data, the average inclination angle of the nacelle is filtered as necessary. The filter includes a second-order low-pass filter and a band-stop filter. The components above the first-order frequency of the tower in the nacelle inclination angle data are attenuated. The effective inclination angle of the nacelle after filtering is expressed as follows:

[0057]

[0058] In the above formula, θ F represents the effective tilt angle of the cabin; F(s) represents the cabin tilt angle filter.

[0059] 2) According to the effective inclination angle of the nacelle, the tower dynamic equation is established and the current effective thrust of the wind rotor is calculated.

[0060] During the operation of the wind turbine, the wind rotor is thrusted by the wind, the tower deforms backward, and the nacelle tilts backward at the same time. The wind rotor thrust is difficult to measure directly, but the effective wind rotor thrust can be calculated based on the effective tilt of the nacelle. The tower dynamics equation is established, and the specific formula is as follows:

[0061]

[0062] In the above formula, F fa represents the effective thrust of the wind rotor; M represents the equivalent inertia of the tower; represents the second-order derivative of the effective inclination angle of the nacelle; D represents the equivalent damping of the tower; represents the first-order derivative of the effective inclination angle of the nacelle; K represents the equivalent stiffness of the tower; θ F Indicates the effective inclination angle of the cabin.

[0063] The specific values ​​of the tower equivalent inertia M, tower equivalent damping D and tower equivalent stiffness K are determined by setting the input step wind in the unit design software Bladed, simulating the change curve of the output wind rotor effective thrust and the effective inclination angle of the nacelle, and obtaining the tower equivalent inertia, tower equivalent damping and tower equivalent stiffness through the least quadratic fitting method.

[0064] 3) According to the currently calculated effective thrust of the wind rotor, determine whether there is a tower clearance risk in the current working condition. If there is a tower clearance risk, execute step 4), otherwise jump back to step 1).

[0065] Due to wind turbulence, tower movement and pitch dynamic effects, the effective thrust of the wind rotor is actually distributed near the steady-state curve of the effective thrust of the wind rotor with wind speed; the steady-state curve of the effective thrust of the wind rotor with wind speed is as follows: Figure 1 As shown, it includes the cut-in wind speed to rated wind speed interval section (i.e., OM section) and the rated wind speed to cut-out wind speed interval section (i.e., ME section); in the cut-in wind speed to rated wind speed interval section, the effective thrust of the wind rotor increases with the increase of the average wind speed; in the rated wind speed to cut-out wind speed interval section, the effective thrust of the wind rotor decreases with the increase of the average wind speed; at the rated wind speed point (i.e., point M), the effective thrust of the wind rotor reaches the maximum value;

[0066] Therefore, the tower clearance risk area can be defined as the AB interval near the rated wind speed, and the effective thrust of the wind rotor is greater than point D; Figure 1 The middle F area is the tower clearance risk area. Since the wind speed measurement is affected by the wake and the wind rotor shielding, the data accuracy is low. Therefore, the boundary of the tower clearance risk area does not need to be judged by wind speed; the left boundary point A of the F area is judged according to the generator power at point A; the right boundary point B of the F area is judged according to the pitch angle at point B. The judgment conditions for defining the tower clearance risk area are as follows:

[0067]

[0068] In the above formula, S f Indicates the tower clearance risk flag, 0 is not in the clearance risk area, 1 is in the clearance risk area; P gen Indicates the measured value of generator power; P A represents the power threshold of the clearance risk area; β represents the average pitch angle of the three blades; β B Indicates the pitch angle threshold in the clearance risk area; F fa Indicates the effective thrust of the wind wheel; F D Indicates the thrust threshold of the clearance risk area; if indicates the following judgment condition; & indicates logical AND operation; else indicates other situations.

[0069] 4) When the unit enters the tower clearance risk area, in the dangerous sector where the blades are close to the tower, set the sector's minimum blade angle to actively increase the tower clearance.

[0070] When the unit is in the tower clearance risk area, the thrust of the wind rotor is large and the blade deformation reaches the maximum; when the blade sweeps through the tower, it is easy for the blade to collide with the tower; therefore, the sector near the tower can be defined as a dangerous sector, such as Figure 2 As shown; when the unit is in the tower clearance risk area and the blade enters the dangerous sector, the purpose of controlling the clearance within a safe range is achieved by setting the minimum blade angle of the blade in the dangerous sector.

[0071] An azimuth sensor is installed in the hub of the wind rotor, which can measure the azimuth of each blade in real time when the wind rotor rotates; Figure 2 The following is a schematic diagram of blade azimuth angles and dangerous sectors. In the figure, the azimuth angle of blade 1 is 30°, the azimuth angle of blade 2 is 150°, and the azimuth angle of blade 3 is 270°. The minimum blade angle of the sector is defined as follows:

[0072]

[0073] In the above formula, β 1，min represents the minimum blade angle of the sector of blade 1; represents the azimuth angle of blade 1; β 2，min represents the minimum blade angle of the sector of blade 2; represents the azimuth angle of blade 2; β 3，min represents the minimum blade angle of the sector of blade 3; represents the azimuth angle of blade 3; represents the lookup table function of the minimum blade angle of the sector; at a certain moment, the minimum blade angle of the sector of the three blades of the wind rotor is as follows Figure 3 shown.

[0074] When the unit is in the tower clearance risk area, the tower clearance risk flag is S f =1. At this time, the pitch control output of each blade pitch command should be compared with the minimum blade angle of each sector, and the larger angle should be selected as the final pitch command. The specific formula is as follows:

[0075]

[0076] In the above formula, β 1 set represents the final pitch command of blade 1; represents the final pitch command of blade 2; represents the final pitch command of blade 3; β 1 c Indicates the blade 1 pitch control command output by the pitch control controller; Indicates the blade 2 pitch control command output by the pitch control controller; represents the pitch command of blade 3 output by the pitch controller; β 1，min represents the minimum blade angle of blade 1; β 2，min represents the minimum blade angle of blade 2; β 3，min Indicates the minimum blade angle of blade 3; max{} indicates the maximum value;

[0077] If the tower clearance risk flag is S f is equal to 0. At this time, there is no tower clearance risk. The pitch command output by the pitch controller does not need to be compared with the minimum blade angle of the sector. The final pitch command is the pitch command output by the pitch controller.

[0078] Example 2

[0079] This embodiment discloses a wind turbine tower clearance control system based on the nacelle inclination angle, which is used to implement the wind turbine tower clearance control method based on the nacelle inclination angle described in Example 1. Figure 4 As shown, the system includes the following functional modules:

[0080] The cabin inclination angle measurement module is used to collect the cabin inclination angle and perform data processing to obtain the cabin effective inclination angle;

[0081] The wind rotor thrust calculation module is used to establish the tower dynamics equation according to the effective inclination angle of the nacelle and calculate the current wind rotor effective thrust;

[0082] The tower clearance warning module is used to determine whether there is a tower clearance risk in the current working condition based on the currently calculated effective thrust of the wind rotor;

[0083] The sector pitch control module is used to set the sector minimum blade angle and actively increase the tower clearance. When the unit enters the tower clearance risk area and is in the dangerous sector where the blades are close to the tower, the pitch command output by the pitch controller is compared with the sector minimum blade angle, and the larger angle is selected as the final pitch command to control the tower clearance in a safe area. When the unit does not have a tower clearance risk, the pitch command output by the pitch controller does not need to be compared with the sector minimum blade angle, and the final pitch command is the pitch command output by the pitch controller.

[0084] Example 3

[0085] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, the wind turbine tower clearance control method based on the nacelle inclination angle described in Embodiment 1 is implemented.

[0086] The storage medium in this embodiment can be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a USB flash drive, a mobile hard disk, or other media.

[0087] Example 4

[0088] This embodiment discloses a computing device, including a processor and a memory for storing a program executable by the processor. When the processor executes the program stored in the memory, the wind turbine tower clearance control method based on the nacelle inclination angle described in Example 1 is implemented.

[0089] The computing device described in this embodiment may be a desktop computer, a laptop computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with a processor function.

[0090] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A wind turbine tower clearance control method based on nacelle inclination angle, characterized in that: Do the following: 1) Collect the cabin inclination angle and process the data to obtain the effective cabin inclination angle; 2) According to the effective inclination angle of the nacelle, the tower dynamic equation is established and the current effective thrust of the wind rotor is calculated; The tower dynamic equation established is as follows: ； In the above formula, Indicates the effective thrust of the wind wheel; represents the equivalent inertia of the tower; Represents the second derivative of the effective inclination angle of the nacelle; represents the equivalent damping of the tower; Represents the first derivative of the effective inclination angle of the nacelle; represents the equivalent stiffness of the tower; Indicates the effective inclination angle of the cabin; 3) According to the currently calculated effective thrust of the wind rotor, determine whether there is a tower clearance risk in the current working condition. If there is a tower clearance risk, execute step 4), otherwise jump back to step 1); 4) When the unit enters the tower clearance risk area, the minimum blade angle of the sector is set in the dangerous sector where the blades are close to the tower. At this time, the pitch command output by the pitch controller must be compared with the minimum blade angle of the sector, and the larger angle is selected as the final pitch command to control the tower clearance in a safe area; when the unit does not have a tower clearance risk, the pitch command output by the pitch controller does not need to be compared with the minimum blade angle of the sector, and the final pitch command is the pitch command output by the pitch controller.

2. A wind turbine tower clearance control method based on nacelle inclination angle according to claim 1, characterized in that: In step 1), the inclination of the nacelle is collected by an inclination sensor, which is installed in the nacelle of the wind turbine and moves together with the nacelle platform to collect the inclination of the nacelle main axis in real time; one or more inclination sensors can be installed in the nacelle, and redundant inclination sensors can increase the reliability of the nacelle inclination measurement; if multiple inclination sensors are used, the multiple inclination measurement values ​​can be combined in a weighted manner to obtain the nacelle inclination, and the specific formula is as follows: ； In the above formula, represents the average inclination angle of the cabin; Indicates the measured inclination of the inclination sensor 1; Represents the weighting coefficient of the tilt sensor 1; Indicates the measured inclination of the inclination sensor 2; represents the weighting coefficient of the tilt sensor 2; represents the measured inclination of the inclination sensor n; Represents the weighting coefficient of the tilt sensor n; Weighting coefficient , arrive The value range is between 0 and 1. The sensor with high precision selects a large weighting coefficient and satisfies the sum of the weighting coefficients. is equal to 1; In order to avoid the interference of high-frequency noise, transmission chain frequency and 3P frequency on the measured data, the average inclination angle of the nacelle is filtered as necessary. The filter includes a second-order low-pass filter and a band-stop filter. The components above the first-order frequency of the tower in the nacelle inclination angle data are attenuated. The effective inclination angle of the nacelle after filtering is expressed as follows: ； In the above formula, Indicates the effective inclination angle of the cabin; Represents the cabin tilt filter.

3. A wind turbine tower clearance control method based on nacelle inclination angle according to claim 1, characterized in that: The tower equivalent inertia , tower equivalent damping and tower equivalent stiffness The specific value of is determined by setting the input step wind in the unit design software Bladed, simulating the change curve of the output wind wheel effective thrust and the effective inclination angle of the nacelle, and obtaining the tower equivalent inertia, tower equivalent damping and tower equivalent stiffness through the least quadratic fitting method.

4. A wind turbine tower clearance control method based on nacelle inclination angle according to claim 1, characterized in that: In step 3), due to wind turbulence, tower movement and pitch dynamic effects, the effective thrust of the wind rotor is actually distributed near the steady-state curve of the effective thrust of the wind rotor versus wind speed; the steady-state curve of the effective thrust of the wind rotor versus wind speed includes a section from the cut-in wind speed to the rated wind speed and a section from the rated wind speed to the cut-out wind speed; in the section from the cut-in wind speed to the rated wind speed, the effective thrust of the wind rotor increases with the increase of the average wind speed; in the section from the rated wind speed to the cut-out wind speed, the effective thrust of the wind rotor decreases with the increase of the average wind speed; at the rated wind speed point, the effective thrust of the wind rotor reaches the maximum value; Therefore, the tower clearance risk area is defined as the interval near the rated wind speed, and this area is defined as the AB area, and the effective thrust of the wind rotor is greater than the rated wind speed point; since the wind speed measurement is affected by the wake and the wind rotor shielding, the data accuracy is low, so the boundary of the tower clearance risk area does not need to be judged by wind speed. The left boundary point A of the tower clearance risk area is judged according to the generator power at point A, and the right boundary point B of the tower clearance risk area is judged according to the pitch angle at point B; the judgment conditions for defining the tower clearance risk area are as follows: ； In the above formula, Indicates the tower clearance risk flag, 0 means it is not in the clearance risk area, 1 means it is in the clearance risk area; Indicates the measured value of generator power; Indicates the power threshold of the clearance risk area; represents the average pitch angle of the three blades; Indicates the pitch angle threshold in the clearance risk area; Indicates the effective thrust of the wind wheel; Indicates the thrust threshold of the clearance risk area; if indicates the following is a judgment condition; Indicates logical AND operation; else indicates other situations.

5. The wind turbine tower clearance control method based on nacelle inclination angle according to claim 1, characterized in that: In step 4), the sector near the tower is defined as a dangerous sector. When the unit is in the tower clearance risk area and the blade enters the dangerous sector, the minimum blade angle of the blade in the dangerous sector is set to achieve the purpose of controlling the clearance within a safe range. An azimuth sensor is installed in the hub of the wind rotor. When the wind rotor rotates, the azimuth of each blade can be measured in real time. The minimum blade angle of the sector is defined as follows: ； In the above formula, represents the minimum blade angle of the sector of blade 1; represents the azimuth angle of blade 1; represents the minimum blade angle of the sector of blade 2; represents the azimuth angle of blade 2; represents the minimum blade angle of the sector of blade 3; represents the azimuth angle of blade 3; Represents the minimum blade angle lookup function of the sector; When the unit is in the tower clearance risk area, the tower clearance risk mark =1. At this time, the pitch control output of each blade pitch command should be compared with the minimum blade angle of each sector, and the larger angle should be selected as the final pitch command. The specific formula is as follows: ； In the above formula, represents the final pitch command of blade 1; represents the final pitch command of blade 2; represents the final pitch change instruction of blade 3; Indicates the blade 1 pitch control command output by the pitch control controller; Indicates the blade 2 pitch control command output by the pitch control controller; represents the pitch command of blade 3 output by the pitch controller; represents the minimum blade angle of the sector of blade 1; represents the minimum blade angle of the sector of blade 2; represents the minimum blade angle of the sector of blade 3; max{} means taking the maximum value; If the tower clearance risk mark is equal to 0. At this time, there is no tower clearance risk. The pitch command output by the pitch controller does not need to be compared with the minimum blade angle of the sector. The final pitch command is the pitch command output by the pitch controller.

6. A wind turbine tower clearance control system based on nacelle inclination, characterized in that: A wind turbine tower clearance control method based on the nacelle inclination angle for implementing any one of claims 1 to 5, comprising: The cabin inclination angle measurement module is used to collect the cabin inclination angle and perform data processing to obtain the cabin effective inclination angle; The wind rotor thrust calculation module is used to establish the tower dynamics equation according to the effective inclination angle of the nacelle and calculate the current wind rotor effective thrust; The tower clearance warning module is used to determine whether there is a tower clearance risk in the current working condition based on the currently calculated effective thrust of the wind rotor; The sector pitch control module is used to set the sector minimum blade angle and actively increase the tower clearance. When the unit enters the tower clearance risk area and is in the dangerous sector where the blades are close to the tower, the pitch command output by the pitch controller is compared with the sector minimum blade angle, and the larger angle is selected as the final pitch command to control the tower clearance in a safe area. When the unit does not have a tower clearance risk, the pitch command output by the pitch controller does not need to be compared with the sector minimum blade angle, and the final pitch command is the pitch command output by the pitch controller.

7. A storage medium storing a program, characterized in that: When the program is executed by a processor, the wind turbine tower clearance control method based on the nacelle inclination angle according to any one of claims 1 to 5 is implemented.

8. A computing device comprising a processor and a memory for storing a program executable by the processor, characterized in that: When the processor executes the program stored in the memory, the wind turbine tower clearance control method based on the nacelle inclination angle according to any one of claims 1 to 5 is implemented.

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