Variable-pitch auxiliary yaw wind facing control method and system for wind turbine generator

Abstract

The invention discloses a variable-pitch auxiliary yaw wind facing control method and system for a wind turbine generator, and the method comprises the steps: planning an optimal yaw track based on the measured cabin direction and average wind direction, and outputting a cabin yaw target angle; according to the cabin yaw target angle, a yaw variable pitch instruction of each blade is calculated and used for generating a yaw moment on a wind wheel plane to push a cabin to yaw; according to the actual yaw rate of the cabin, a yaw resistance-increasing pitch-changing instruction of each blade is calculated and used for controlling the yaw rate to be stable in the yaw process of the cabin; the yaw variable pitch instruction and the yaw resistance-increasing variable pitch instruction of each blade are superposed and then superposed with a unified variable pitch instruction given by a unit, and a final variable pitch instruction of each blade is obtained; and the final variable-pitch instruction of each blade is transmitted to a variable-pitch system of the unit, and the variable-pitch system drives the blades to change the pitch, so that a cabin is driven to yaw. The problem of insufficient yaw driving capacity can be effectively solved, and the number of yaw driving motors is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a method, system, storage medium and computing device for variable pitch assisted yaw wind control of a wind turbine. Background Art

[0002] At present, wind turbines are gradually developing towards large-scale development. The super-long blades make the wind turbines have a larger wind sweeping area, and the power generation and full-power hours of the units are significantly improved. However, after the wind turbines are enlarged, the load on the wind rotor also increases sharply. This has caused many problems, among which the yaw system is subjected to higher loads, resulting in insufficient yaw system drive capacity. Although the yaw drive capacity can be improved by increasing the number of yaw drive motors, it also increases the cost of the whole machine. In addition, the space for yaw drive motors is limited, which brings great technical difficulties to the design of the yaw system. Summary of the invention

[0003] The first purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a pitch-assisted yaw control method for a wind turbine. Based on the measured cabin direction and average wind direction, the optimal yaw trajectory is planned, and the cabin yaw is driven by superimposing pitch-assisted commands, which can effectively solve the problem of insufficient yaw drive capability and reduce the number of yaw drive motors.

[0004] A second object of the present invention is to provide a variable pitch assisted yaw wind control system for a wind turbine.

[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 variable pitch assisted yaw wind control method for a wind turbine generator system, comprising:

[0008] Based on the measured cabin direction and average wind direction, the optimal yaw trajectory is planned and the cabin yaw target angle is output;

[0009] According to the yaw target angle of the nacelle, the yaw pitch command of each blade is calculated to generate a yaw moment on the wind rotor plane to push the nacelle to yaw, so that the nacelle faces the wind;

[0010] According to the actual yaw rate of the cabin, the yaw resistance pitch change command of each blade is calculated to control the yaw rate to be stable during the yaw process of the cabin, so as to achieve the purpose of uniform yaw of the cabin to the wind;

[0011] The yaw pitch control command of each blade is superimposed with the yaw resistance pitch control command, and then superimposed with the unified pitch control command given by the unit to obtain the final pitch control command of each blade;

[0012] The final pitch control command of each blade is transmitted to the pitch control system of the unit, and the pitch control system drives the blade to change pitch, thereby driving the cabin to yaw.

[0013] Furthermore, in order to make the direction of the cabin track the average wind direction, it is necessary to calculate the optimal yaw trajectory from the current cabin direction to the average wind direction. When the cabin direction coincides with the average wind direction, the yaw error is zero, and the wind turbine is facing the wind direction at this time; the average wind direction is obtained by first collecting the real-time wind direction through the cabin wind vane, and then filtering the real-time wind direction through an average value filter.

[0014] Furthermore, the cabin direction is obtained by directly measuring the cabin north sensor.

[0015] Further, the calculation formula of the average wind direction is as follows:

[0016]

[0017] In the above formula, t represents the time variable, θ wind (t) represents the real-time wind direction collected by the cabin wind vane, Indicates the average wind direction after the average filter, F θ (s) represents a low-pass filter.

[0018] Furthermore, the low-pass filter is one or more combinations of a first-order low-pass filter, a second-order low-pass filter, and an average value filter.

[0019] Furthermore, the optimal yaw trajectory is planned, which is subdivided into four working modes, namely mode 0, mode 1, mode -1 and mode 2. The default working mode is mode 0 in the initialization state, and the cabin yaw target angle is initially in the same direction as the cabin direction;

[0020] Mode 0: The cabin yaw target angle remains constant until the deviation between the average wind direction and the cabin yaw target angle exceeds the set yaw error threshold, then switch to working mode; if this deviation is greater than zero, switch to mode 1; if this deviation is less than zero, switch to mode -1; when the deviation between the average wind direction and the cabin yaw target angle does not exceed the set yaw error threshold, keep the working mode at mode 0;

[0021]

[0022]

[0023] In the above formula, t represents the time variable, Δt represents the time step, Indicates the cabin yaw target angle at the current moment, represents the cabin yaw target angle at the previous moment, Mode represents the mode variable, H represents the yaw error threshold, represents the average wind direction after passing through the average filter, It represents the absolute value of the difference between the average wind direction and the yaw target angle, and is used to measure the deviation between the average wind direction and the cabin yaw target angle;

[0024] Mode 1: The cabin yaw target angle maintains a constant rate output, the rate is positive, and the average wind direction is tracked clockwise until the deviation between the average wind direction and the cabin yaw target angle is close to or equal to zero, then the working mode is switched to mode 2; a very small positive number is applied, if the deviation is less than this positive number, it is judged to be close to or equal to zero; if this deviation is greater than this positive number, the current working mode 1 is maintained unchanged;

[0025]

[0026]

[0027] In the above formula, ν represents the cabin yaw rate, and ε represents the minimum threshold for stopping yaw, which is set to a very small positive number;

[0028] Mode-1: The cabin yaw target angle maintains a constant rate output, the rate is negative, and the average wind direction is tracked counterclockwise until the deviation between the average wind direction and the cabin yaw target angle is close to or equal to zero, then the working mode is switched to mode 2; a very small positive number is applied, if the deviation is less than this positive number, it is judged to be close to or equal to zero; if this deviation is greater than this positive number, the current working mode -1 is maintained unchanged;

[0029]

[0030]

[0031] Mode 2: When entering Mode 2, the cabin yaw target angle remains constant, a timer is initialized to zero, and starts timing. If the time of the timer exceeds the set yaw rest time threshold, the mode is switched back to Mode 0. The purpose of Mode 2 is to ensure that there is enough cooling time before starting the yaw action again.

[0032]

[0033]

[0034] In the above formula, Timer(t) represents the timer, and T0 represents the yaw rest time threshold.

[0035] Furthermore, based on the output cabin yaw target angle, compared with the cabin direction, the yaw drive torque is obtained through proportional and integral operations. The calculation formula of the yaw drive torque is as follows:

[0036]

[0037] In the above formula, t represents the time variable, M yaw (t) represents the yaw drive torque, k p represents the proportional gain of yaw to wind control, k i represents the integral gain of yaw to wind control, Indicates the cabin yaw target angle at the current moment, represents the direction of the cabin at the current moment, ∫(·)dt represents the integral operation over time;

[0038] To generate a yaw drive torque on the wind rotor, it is necessary to apply different yaw pitch commands to the three blades. Since the thrust of each blade is different, a yaw drive torque is generated on the wind rotor plane. The yaw pitch command calculation formula for the three blades is as follows:

[0039]

[0040] In the above formula, Δβ 1,yaw represents the yaw pitch command of blade 1, Δβ 2,yaw represents the yaw pitch command of blade 2, Δβ 3,yaw represents the yaw pitch command of blade 3, H β represents the conversion factor from bending moment to pitch, θ A (t) represents the azimuth angle of blade 1, which is measured by the azimuth angle sensor, θ ph Indicates phase lead compensation.

[0041] Furthermore, based on the measured nacelle direction, the nacelle yaw rate is obtained by differential operation, and the yaw drag moment is obtained by proportional operation. The calculation formula of the yaw drag moment is as follows:

[0042]

[0043] In the above formula, M damper (t) represents the yaw drag moment, k damper Indicates the proportional gain of yaw resistance control, F damper (s) represents the yaw resistance low-pass filter, represents the differential operation on the cabin direction, Indicates the cabin direction at the current moment;

[0044] To generate a yaw drag moment on the wind rotor, it is necessary to apply different yaw drag pitch commands to the three blades. Since the thrust of each blade is different, a yaw drag moment is generated on the wind rotor plane. The calculation formula for the yaw drag pitch command of the three blades is as follows:

[0045]

[0046] In the above formula, Δβ 1,damper represents the yaw resistance pitch change command of blade 1, Δβ 2,damper represents the yaw resistance pitch change command of blade 2, Δβ 3,damper Indicates the yaw resistance pitch change command of blade 3, H β represents the conversion factor from bending moment to pitch, θ A (t) represents the azimuth angle of blade 1, which is measured by the azimuth angle sensor, θ ph Indicates phase lead compensation.

[0047] Furthermore, the calculation formula of the final pitch command is as follows:

[0048]

[0049] In the above formula, represents the final pitch command of blade 1, represents the final pitch command of blade 2, represents the final pitch command of blade 3, Δβ 1,yaw represents the yaw pitch command of blade 1, Δβ 2,yaw represents the yaw pitch command of blade 2, Δβ 3,yaw represents the yaw pitch command of blade 3, Δβ 1,damper represents the yaw resistance pitch change command of blade 1, Δβ 2,damper represents the yaw resistance pitch change command of blade 2, Δβ 3,damper represents the yaw resistance pitch change command of blade 3, β c Indicates unified pitch change command.

[0050] The second object of the present invention is achieved through the following technical solution: a variable pitch assisted yaw wind control system for a wind turbine, used to implement the variable pitch assisted yaw wind control method for the wind turbine, comprising:

[0051] The yaw trajectory planning module plans the optimal yaw trajectory based on the measured cabin direction and average wind direction, and outputs the cabin yaw target angle;

[0052] The yaw-to-wind control module calculates the yaw pitch command of each blade according to the yaw target angle of the cabin, which is used to generate a yaw moment on the plane of the wind rotor to push the cabin to yaw, so as to achieve the purpose of the cabin facing the wind;

[0053] The yaw active drag module calculates the yaw drag pitch change command for each blade according to the actual yaw rate of the cabin, which is used to control the yaw rate to be stable during the yaw process of the cabin, so as to achieve the purpose of uniform yaw of the cabin against the wind;

[0054] The pitch command superposition module is used to superimpose the yaw pitch command of each blade with the yaw resistance pitch command, and then superimpose them with the unified pitch command given by the unit to obtain the final pitch command for each blade.

[0055] 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 variable pitch assisted yaw wind control method of the wind turbine is implemented.

[0056] 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 programs executable by the processor, when the processor executes the program stored in the memory, the above-mentioned variable pitch assisted yaw wind control method of the wind turbine group is implemented.

[0057] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0058] 1. The present invention drives the nacelle to yaw by superimposing a pitch change instruction on the pitch change, thereby solving the problem of insufficient yaw drive capability, reducing the number of yaw drive motors, and reducing the cost of the entire machine.

[0059] 2. The present invention has good yaw-to-wind accuracy by calculating the optimal yaw trajectory, making the yaw-to-wind safe and reliable.

[0060] 3. The present invention controls the yaw rate to stabilize the yaw process of the cabin and reduce the fluctuation and vibration of the yaw rate during the yaw process. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 An architectural diagram of the system of the present invention. DETAILED DESCRIPTION

[0062] 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.

[0063] Example 1

[0064] This embodiment discloses a method for wind turbine generator set to control wind with variable pitch assisted yaw, and the details are as follows:

[0065] 1) In order to make the direction of the cabin track the average wind direction, it is necessary to calculate the optimal yaw trajectory from the current cabin direction to the average wind direction; when the cabin direction coincides with the average wind direction, the yaw error is zero, and the wind turbine is facing the wind direction; the cabin direction is directly measured by the cabin north sensor; the average wind direction is obtained by first collecting the real-time wind direction through the cabin wind vane, and then filtering the real-time wind direction through the average value filter.

[0066] First, calculate the current average wind direction, the calculation formula is as follows:

[0067]

[0068] In the above formula, t represents the time variable, θ wind (t) represents the real-time wind direction collected by the cabin wind vane, Indicates the average wind direction after the average filter, F θ (s) represents a low-pass filter.

[0069] The low-pass filter may be a first-order low-pass filter, a second-order low-pass filter, an average value filter, or a combination thereof.

[0070] Secondly, the optimal yaw operation trajectory is planned (i.e., the optimal yaw trajectory is planned) and the yaw target angle of the cabin is output.

[0071] This part is subdivided into four working modes, namely mode 0, mode 1, mode -1 and mode 2. The default working mode is mode 0 in the initialization state, and the cabin yaw target angle is initially in the same direction as the cabin direction;

[0072] Mode 0: The cabin yaw target angle remains constant until the deviation between the average wind direction and the cabin yaw target angle exceeds the set yaw error threshold, then switch to working mode; if this deviation is greater than zero, switch to mode 1; if this deviation is less than zero, switch to mode -1; when the deviation between the average wind direction and the cabin yaw target angle does not exceed the set yaw error threshold, keep the working mode at mode 0;

[0073]

[0074]

[0075] In the above formula, t represents the time variable, Δt represents the time step, Indicates the cabin yaw target angle at the current moment, represents the cabin yaw target angle at the previous moment, Mode represents the mode variable, H represents the yaw error threshold, represents the average wind direction after passing through the average filter, It represents the absolute value of the difference between the average wind direction and the yaw target angle, and is used to measure the deviation between the average wind direction and the cabin yaw target angle;

[0076] Mode 1: The cabin yaw target angle is output at a constant rate, the rate is positive, and the average wind direction is tracked clockwise until the deviation between the average wind direction and the cabin yaw target angle is close to or equal to zero (that is, almost zero), then the working mode is switched to mode 2; a very small positive number is applied, if the deviation is less than this positive number, it is judged to be close to or equal to zero; if this deviation is greater than this positive number, the current working mode 1 is maintained unchanged;

[0077]

[0078]

[0079] In the above formula, v represents the cabin yaw rate, ε represents the minimum threshold for stopping yaw, which is set to a very small positive number;

[0080] Mode-1: The cabin yaw target angle maintains a constant rate output, the rate is negative, and the average wind direction is tracked counterclockwise until the deviation between the average wind direction and the cabin yaw target angle is close to or equal to zero, then the working mode is switched to mode 2; a very small positive number is applied, if the deviation is less than this positive number, it is judged to be close to or equal to zero; if this deviation is greater than this positive number, the current working mode -1 is maintained unchanged;

[0081]

[0082]

[0083] Mode 2: When entering Mode 2, the cabin yaw target angle remains constant, a timer is initialized to zero, and starts timing. If the time of the timer exceeds the set yaw rest time threshold, the mode is switched back to Mode 0. The purpose of Mode 2 is to ensure that there is enough cooling time before starting the yaw action again.

[0084]

[0085]

[0086] In the above formula, Timer(t) represents the timer, and T0 represents the yaw rest time threshold.

[0087] 2) According to the yaw target angle of the nacelle, the yaw pitch command of each blade is calculated to generate a yaw moment in the wind rotor plane to push the nacelle to yaw, so as to achieve the purpose of the nacelle facing the wind.

[0088] First, the yaw drive torque is calculated.

[0089] Based on the output cabin yaw target angle, compared with the cabin direction, the yaw drive torque is obtained through proportional and integral operations. The calculation formula of the yaw drive torque is as follows:

[0090]

[0091] In the above formula, t represents the time variable, M yaw (t) represents the yaw drive torque, k p represents the proportional gain of yaw to wind control, k i represents the integral gain of yaw to wind control, Indicates the cabin yaw target angle at the current moment, represents the direction of the cabin at the current moment, and ∫(·)dt represents the integration operation with respect to time.

[0092] Secondly, the yaw pitch control commands of the three blades are calculated.

[0093] To generate a yaw drive torque on the wind rotor, it is necessary to apply different yaw pitch commands to the three blades. Since the thrust of each blade is different, a yaw drive torque is generated on the wind rotor plane. The yaw pitch command calculation formula for the three blades is as follows:

[0094]

[0095] In the above formula, Δβ 1,yaw represents the yaw pitch command of blade 1, Δβ 2,yaw represents the yaw pitch command of blade 2, Δβ 3,yaw represents the yaw pitch command of blade 3, H β represents the conversion factor from bending moment to pitch, θ A (t) represents the azimuth angle of blade 1, which is measured by the azimuth angle sensor, θ ph Indicates phase lead compensation.

[0096] 3) According to the actual yaw rate of the cabin, the yaw resistance pitch change command of each blade is calculated to control the yaw rate to be stable during the yaw of the cabin, so as to achieve the purpose of uniform yaw of the cabin against the wind.

[0097] First, the yaw drag moment is calculated.

[0098] Based on the measured cabin direction, the cabin yaw rate is obtained through differential operation, and the yaw drag moment is obtained through proportional operation. The calculation formula of the yaw drag moment is as follows:

[0099]

[0100] In the above formula, M damper (t) represents the yaw drag moment, k damperIndicates the proportional gain of yaw resistance control, F damper (s) represents the yaw resistance low-pass filter, represents the differential operation on the cabin direction, Indicates the cabin direction at the current moment.

[0101] Secondly, the yaw, drag and pitch control commands of the three blades are calculated.

[0102] To generate a yaw drag moment on the wind rotor, it is necessary to apply different yaw drag pitch commands to the three blades. Since the thrust of each blade is different, a yaw drag moment is generated on the wind rotor plane. The calculation formula for the yaw drag pitch command of the three blades is as follows:

[0103]

[0104] In the above formula, Δβ 1,damper represents the yaw resistance pitch change command of blade 1, Δβ 2,damper represents the yaw resistance pitch change command of blade 2, Δβ 3,damper Indicates the yaw resistance pitch change command of blade 3, H β represents the conversion factor from bending moment to pitch, θ A (t) represents the azimuth angle of blade 1, which is measured by the azimuth angle sensor, θ ph Indicates phase lead compensation.

[0105] 4) After superimposing the yaw pitch control command of each blade with the yaw resistance pitch control command, the command is then superimposed with the unified pitch control command given by the unit to obtain the final pitch control command of each blade;

[0106] The calculation formula for the final pitch command is as follows:

[0107]

[0108] In the above formula, represents the final pitch command of blade 1, represents the final pitch command of blade 2, represents the final pitch command of blade 3, Δβ 1,yaw represents the yaw pitch command of blade 1, Δβ 2,yaw represents the yaw pitch command of blade 2, Δβ 3,yaw represents the yaw pitch command of blade 3, Δβ 1,damper represents the yaw resistance pitch change command of blade 1, Δβ 2,damper represents the yaw resistance pitch change command of blade 2, Δβ 3,damper represents the yaw resistance pitch change command of blade 3, β c Indicates unified pitch change command.

[0109] 5) The final pitch change command of each blade is transmitted to the pitch change system of the unit, and the pitch change system drives the blade to change the pitch to achieve the yaw of the cabin.

[0110] Example 2

[0111] This embodiment discloses a wind turbine generator set pitch-assisted yaw control system, which is used to implement the wind turbine generator set pitch-assisted yaw control method described in Embodiment 1. Figure 1 As shown, including:

[0112] The yaw trajectory planning module plans the optimal yaw trajectory based on the measured cabin direction and average wind direction, and outputs the cabin yaw target angle;

[0113] The yaw-to-wind control module calculates the yaw pitch command of each blade according to the yaw target angle of the cabin, which is used to generate a yaw moment on the plane of the wind rotor to push the cabin to yaw, so as to achieve the purpose of the cabin facing the wind;

[0114] The yaw active drag module calculates the yaw drag pitch change command for each blade according to the actual yaw rate of the cabin, which is used to control the yaw rate to be stable during the yaw process of the cabin, so as to achieve the purpose of uniform yaw of the cabin against the wind;

[0115] The pitch command superposition module is used to superimpose the yaw pitch command of each blade with the yaw resistance pitch command, and then superimpose them with the unified pitch command given by the unit to obtain the final pitch command for each blade.

[0116] Example 3

[0117] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, the pitch-assisted yaw wind control method of the wind turbine set described in Embodiment 1 is implemented.

[0118] 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.

[0119] Example 4

[0120] This embodiment discloses a computing device, including a processor and a memory for storing programs executable by the processor. When the processor executes the program stored in the memory, the variable pitch assisted yaw wind control method of the wind turbine set described in Example 1 is implemented.

[0121] 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.

[0122] 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 variable pitch assisted yaw wind control method for a wind turbine, characterized in that: include: Based on the measured cabin direction and average wind direction, the optimal yaw trajectory is planned and the cabin yaw target angle is output; According to the yaw target angle of the nacelle, the yaw pitch command of each blade is calculated to generate a yaw moment on the wind rotor plane to push the nacelle to yaw, so that the nacelle faces the wind; According to the actual yaw rate of the cabin, the yaw resistance pitch change command of each blade is calculated to control the yaw rate to be stable during the yaw process of the cabin, so as to achieve the purpose of uniform yaw of the cabin to the wind; The yaw pitch control command of each blade is superimposed with the yaw resistance pitch control command, and then superimposed with the unified pitch control command given by the unit to obtain the final pitch control command of each blade; The final pitch control command of each blade is transmitted to the pitch control system of the unit, and the pitch control system drives the blade to change pitch, thereby driving the cabin to yaw.

2. A variable pitch assisted yaw wind control method for a wind turbine according to claim 1, characterized in that: In order to make the direction of the cabin track the average wind direction, it is necessary to calculate the optimal yaw trajectory from the current cabin direction to the average wind direction. When the cabin direction coincides with the average wind direction, the yaw error is zero, and the wind turbine is facing the wind direction. The average wind direction is obtained by first collecting the real-time wind direction through the cabin wind vane, and then filtering the real-time wind direction through the average value filter.

3. A variable pitch assisted yaw wind control method for a wind turbine according to claim 2, characterized in that: The cabin direction is obtained by directly measuring the cabin north sensor.

4. A variable pitch assisted yaw wind control method for a wind turbine according to claim 2, characterized in that: The calculation formula of the average wind direction is as follows: In the above formula, t represents the time variable, θ wind (t) represents the real-time wind direction collected by the cabin wind vane, Indicates the average wind direction after the average filter, F θ (s) represents a low-pass filter.

5. A variable pitch assisted yaw wind control method for a wind turbine according to claim 4, characterized in that: The low-pass filter is one or more combinations of a first-order low-pass filter, a second-order low-pass filter, and an average value filter.

6. A variable pitch assisted yaw wind control method for a wind turbine according to claim 1, characterized in that: Plan the optimal yaw trajectory, which is divided into four working modes: mode 0, mode 1, mode -1 and mode 2. The default working mode is mode 0 in the initialization state, and the cabin yaw target angle is initially in the same direction as the cabin direction; Mode 0: The cabin yaw target angle remains constant until the deviation between the average wind direction and the cabin yaw target angle exceeds the set yaw error threshold, then switch to working mode; if this deviation is greater than zero, switch to mode 1; if this deviation is less than zero, switch to mode -1; When the deviation between the average wind direction and the cabin yaw target angle does not exceed the set yaw error threshold, the working mode is maintained at mode 0; In the above formula, t represents the time variable, Δt represents the time step, Indicates the cabin yaw target angle at the current moment, represents the cabin yaw target angle at the previous moment, Mode represents the mode variable, H represents the yaw error threshold, represents the average wind direction after passing through the average filter, It represents the absolute value of the difference between the average wind direction and the yaw target angle, and is used to measure the deviation between the average wind direction and the cabin yaw target angle; Mode 1: The cabin yaw target angle maintains a constant rate output, the rate is positive, and the average wind direction is tracked clockwise until the deviation between the average wind direction and the cabin yaw target angle is close to or equal to zero, then the working mode is switched to mode 2; a very small positive number is applied, if the deviation is less than this positive number, it is judged to be close to or equal to zero; if this deviation is greater than this positive number, the current working mode 1 is maintained unchanged; In the above formula, v represents the cabin yaw rate, ε represents the minimum threshold for stopping yaw, which is set to a very small positive number; Mode-1: The cabin yaw target angle maintains a constant rate output, the rate is negative, and the average wind direction is tracked counterclockwise until the deviation between the average wind direction and the cabin yaw target angle is close to or equal to zero, then the working mode is switched to mode 2; a very small positive number is applied, if the deviation is less than this positive number, it is judged to be close to or equal to zero; if this deviation is greater than this positive number, the current working mode -1 is maintained unchanged; Mode 2: When entering Mode 2, the cabin yaw target angle remains constant, a timer is initialized to zero, and starts timing. If the time of the timer exceeds the set yaw rest time threshold, the mode is switched back to Mode 0. The purpose of Mode 2 is to ensure that there is enough cooling time before starting the yaw action again. In the above formula, Timer(t) represents the timer, and T0 represents the yaw rest time threshold.

7. A variable pitch assisted yaw wind control method for a wind turbine according to claim 1, characterized in that: Based on the output cabin yaw target angle, compared with the cabin direction, the yaw drive torque is obtained through proportional and integral operations. The calculation formula of the yaw drive torque is as follows: In the above formula, t represents the time variable, M yaw (t) represents the yaw drive torque, k p represents the proportional gain of yaw to wind control, k i represents the integral gain of yaw to wind control, Indicates the cabin yaw target angle at the current moment, represents the direction of the cabin at the current moment, ∫(·)dt represents the integral operation over time; To generate a yaw drive torque on the wind rotor, it is necessary to apply different yaw pitch commands to the three blades. Since the thrust of each blade is different, a yaw drive torque is generated on the wind rotor plane. The yaw pitch command calculation formula for the three blades is as follows: In the above formula, Δβ 1,yaw represents the yaw pitch command of blade 1, Δβ 2,yaw represents the yaw pitch command of blade 2, Δβ 3,yaw represents the yaw pitch command of blade 3, H β represents the conversion factor from bending moment to pitch, θ A (t) represents the azimuth angle of blade 1, which is measured by the azimuth angle sensor, θ ph Indicates phase lead compensation.

8. The pitch-assisted yaw wind control method for a wind turbine according to claim 1, characterized in that: Based on the measured cabin direction, the cabin yaw rate is obtained through differential operation, and the yaw drag moment is obtained through proportional operation. The calculation formula of the yaw drag moment is as follows: In the above formula, M damper (t) represents the yaw drag moment, k damper Indicates the proportional gain of yaw resistance control, F damper (s) represents the yaw resistance low-pass filter, represents the differential operation on the cabin direction, Indicates the cabin direction at the current moment; To generate a yaw drag moment on the wind rotor, it is necessary to apply different yaw drag pitch commands to the three blades. Since the thrust of each blade is different, a yaw drag moment is generated on the wind rotor plane. The calculation formula for the yaw drag pitch command of the three blades is as follows: In the above formula, Δβ 1,damper represents the yaw resistance pitch change command of blade 1, Δβ 2,damper represents the yaw resistance pitch change command of blade 2, Δβ 3,damper Indicates the yaw resistance pitch change command of blade 3, H β represents the conversion factor from bending moment to pitch, θ A (t) represents the azimuth angle of blade 1, which is measured by the azimuth angle sensor, θ ph Indicates phase lead compensation.

9. A variable pitch assisted yaw wind control method for a wind turbine according to claim 8, characterized in that: The calculation formula for the final pitch command 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 command of blade 3, Δβ 1,yaw represents the yaw pitch command of blade 1, Δβ 2,yaw represents the yaw pitch command of blade 2, Δβ 3,yaw represents the yaw pitch command of blade 3, Δβ 1,damper represents the yaw resistance pitch change command of blade 1, Δβ 2,damper represents the yaw resistance pitch change command of blade 2, Δβ 3,damper represents the yaw resistance pitch change command of blade 3, β c Indicates unified pitch change command.

10. A variable pitch assisted yaw wind control system for a wind turbine, characterized in that: A method for implementing a pitch-assisted yaw wind control method for a wind turbine set according to any one of claims 1 to 9, comprising: The yaw trajectory planning module plans the optimal yaw trajectory based on the measured cabin direction and average wind direction, and outputs the cabin yaw target angle; The yaw-to-wind control module calculates the yaw pitch command of each blade according to the yaw target angle of the cabin, which is used to generate a yaw moment on the wind rotor plane to push the cabin to yaw, so as to achieve the purpose of the cabin facing the wind; The yaw active drag module calculates the yaw drag pitch change command for each blade according to the actual yaw rate of the cabin, which is used to control the yaw rate to be stable during the yaw process of the cabin, so as to achieve the purpose of uniform yaw of the cabin against the wind; The pitch command superposition module is used to superimpose the yaw pitch command of each blade with the yaw resistance pitch command, and then superimpose them with the unified pitch command given by the unit to obtain the final pitch command for each blade.

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