A method, system and storage medium for reducing load and yaw control of a wind turbine generator

Abstract

The present invention provides a load-reducing yaw control method for a wind turbine generator. By analyzing the root load data of the blades before the yaw of the unit is started, the stress condition of the yaw is predicted. When it is predicted that the yaw stress exceeds the limit, a load-reducing strategy is started in a timely manner before the yaw is started to reduce the stress during yaw and ensure the safe and reliable yaw of the unit. The present invention also provides a load-reducing yaw control system for a wind turbine generator. A plurality of strain sensors are installed at the root position of each blade to measure the unbalanced load of the blade before the yaw is started, and the yaw load is estimated and calculated by determining the blade unbalance degree; then, the angle of the blade is changed to reduce the unbalanced load of the blade, and the yaw action is carried out when the load is reduced to a suitable yaw load. Through this active control of the yaw load of the wind turbine generator, the safe and stable yaw of the doubly-fed wind turbine unit is realized. At the same time, the present invention also provides a computer-readable storage medium storing a program for realizing the information transfer of the load-reducing yaw control method.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and particularly relates to a method, a system and a storage medium for reducing load and yaw control of a wind turbine generator set. Background Art

[0002] In recent years, the blade lengths of large wind turbine generator sets have increased sharply, the swept area of the units has increased, and the wake flow and turbulence of other upwind units near the machine position will cause the forces on the long blades to be unbalanced, thus greatly affecting the yaw load of the units. In extreme cases, it will cause the unit to be blown and rapidly reverse when yawing, resulting in damage to the yaw motor and yaw gearbox. Therefore, a control method is needed to avoid yawing when there is a large unbalanced load on the wind turbine rotor. Summary of the Invention

[0003] Aiming at the defects in the prior art, the present invention provides a method, a system and a storage medium for reducing load and yaw control of a wind turbine generator set to solve the technical problem that starting yaw when the blades are greatly unbalanced due to force is likely to cause damage to the yaw motor and yaw gearbox.

[0004] To achieve the above object, the present invention is realized by the following technical solutions:

[0005] In the first aspect of the present invention, a method for reducing load and yaw control of a wind turbine generator set is provided, including the following steps:

[0006] After receiving a yaw start command, measure the strain force of each blade of the wind turbine generator set;

[0007] Calculate the influence quantization value of the strain force of each blade on the yaw load;

[0008] Based on the calculated influence quantization values of the three blades, make the following judgments:

[0009] If only the influence quantization value of one blade exceeds the blade design yaw limit, control the blade to feather until the influence quantization value of the blade is lower than the blade design yaw limit and then resume normal control;

[0010] If the influence quantization values of at least two blades exceed the blade design yaw limit, control the three blades of the unit to feather, and at the same time reduce the unit speed and torque until the influence quantization values of the three blades are all lower than the blade design yaw limit and then resume normal control;

[0011] If the influence quantization values of the three blades are all lower than the blade design yaw limit, start the yaw program.

[0012] Optionally, the measuring the strain force of each blade of the wind turbine generator set includes:

[0013] At least four data acquisition points are arranged at the root of each blade to collect the acquisition data of each data acquisition point.

[0014] Optionally, to calculate the quantification value of the influence of the strain force of each blade on the yaw load, the following formula is adopted:

[0015] Quantification value of the influence of blade 1: T1 = αsinθL1σ1m1n 2

[0016] Quantification value of the influence of blade 2: T2 = αsin(θ + 120°)L2σ2m2n 2

[0017] Quantification value of the influence of blade 3: T3 = αsin(θ - 120°)L3σ3m3n 2

[0018] Where α is a constant value obtained from the blade airfoil, θ is the wind turbine zero position angle, L is the length of the blade, σ is the stress value received at the blade root, m is the blade mass, and n is the angular velocity of the wind turbine rotation.

[0019] In a second aspect of the present invention, a yaw control system for reducing the load of a wind turbine generator set is provided, including:

[0020] A data acquisition module, configured to measure the strain force of each blade of the wind turbine generator set after receiving a yaw start instruction;

[0021] A data processing module, configured to calculate the quantification value of the influence of the strain force of each blade on the yaw load based on the strain force of each blade collected by the data acquisition module;

[0022] A condition determination module, configured to make the following determinations based on the quantification values of the influence of the three blades obtained by calculation:

[0023] If the quantification value of the influence of only one blade exceeds the blade design yaw limit, control the blade to feather until the quantification value of this blade is lower than the blade design yaw limit and then resume normal control;

[0024] If the quantification values of the influence of at least two blades exceed the blade design yaw limit, control the three blades of the unit to feather, and at the same time reduce the rotational speed and torque of the unit until the quantification values of the influence of the three blades are lower than the blade design yaw limit and then resume normal control;

[0025] If the quantification values of the influence of the three blades are all lower than the blade design yaw limit, start the yaw program.

[0026] Optionally, the data acquisition module includes fiber Bragg grating strain sensors, and at least four of the fiber Bragg grating strain sensors are arranged at the root of each blade.

[0027] In a third aspect of the present invention, there is provided a computer-readable storage medium having an implementation program for information transmission stored thereon. When the program is executed by a processor, the steps of a yaw control method for reducing the load of a wind turbine generator set as described in any one of the above are implemented.

[0028] As can be seen from the above technical solutions, the beneficial effects of the present invention are:

[0029] A yaw control method for reducing the load of a wind turbine generator set provided by the present invention estimates the stress condition of yaw through the analysis of the root load data of the blades before the yaw of the unit. When it is predicted that the yaw stress exceeds the limit, the load reduction strategy is started in a timely manner before the yaw is started, reducing the stress during yaw and ensuring the safe and reliable yaw of the unit.

[0030] A yaw control system for reducing the load of a wind turbine generator set provided by the present invention installs several strain sensors at the root position of each blade. Before the yaw is started, the unbalanced load of the blade is measured, and the unbalance degree of the blade is determined to complete the estimation calculation of the yaw load; then, by changing the angle of the blade, the unbalanced load of the blade is reduced, and when the yaw load is reduced to an appropriate value, the yaw action is performed. Through this active control of the yaw load of the wind turbine generator, the safe and stable yaw of the doubly-fed wind turbine generator set is realized. Description of the Drawings

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0032] Figure 1 It is a flowchart of a yaw control method for reducing the load of a wind turbine generator set. Detailed Embodiments

[0033] The following will describe in detail the embodiments of the technical solutions of the present invention with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and therefore are only examples and cannot be used to limit the protection scope of the present invention.

[0034] Please refer to Figure 1 , a yaw control method for reducing the load of a wind turbine generator set provided by the present invention includes the following steps:

[0035] S1. After receiving a yaw start command, measure the strain force of each blade of the wind turbine generator set;

[0036] At least four data acquisition points are arranged at the root of each blade to collect the acquisition data of each data acquisition point to make the detection value more accurate;

[0037] S2. Calculate the quantification value of the influence of the strain force of each blade on the yaw load based on the measured strain force of each blade;

[0038] Specifically, the following formula can be used:

[0039] Quantification value of the influence of blade 1: T1 = αsinθL1σ1m1n 2

[0040] Quantification value of the influence of blade 2: T2 = αsin(θ + 120°)L2σ2m2n 2

[0041] Quantification value of the influence of blade 3: T3 = αsin(θ - 120°)L3σ3m3n 2

[0042] Where α is a constant obtained from the blade airfoil, θ is the wind turbine zero position angle, L is the blade length, σ is the stress value received at the blade root, m is the blade mass, and n is the angular velocity of the wind turbine rotation;

[0043] S3. Based on the calculated quantification values of the influence of the three blades, make the following judgments:

[0044] If the quantification value of the influence of the force of only one blade on the yaw load exceeds the blade design yaw limit Tmax, control the blade to feather until the quantification value of this blade is lower than the blade design yaw limit Tmax and then resume normal control; among them, the value of Tmax is directly related to the yaw drive probability during the design of the unit. The greater the selected drive capacity of the yaw drive during design, the larger the value of Tmax. Conversely, the value becomes smaller. At the same time, the size of this value is also related to the power rating of the wind turbine and the blade length;

[0045] If the quantification values of the influence of the forces of at least two blades on the yaw load exceed the blade design yaw limit Tmax, control the three blades of the unit to feather, and at the same time reduce the rotational speed and torque of the unit until the quantification values of the three blades are all lower than the blade design yaw limit Tmax and then resume normal control;

[0046] If the quantification values of the influence of the forces of the three blades on the yaw load are all lower than the blade design yaw limit Tmax, the yaw program can be started.

[0047] A yaw load reduction control method for a wind power generation unit provided by the present invention pre-estimates the yaw force condition through the analysis of the root load data of the blades before the unit yaw starts. When it is predicted that the yaw force exceeds the limit, the load reduction strategy is started in time before the yaw starts to reduce the force during yaw and ensure the safe and reliable yaw of the unit. Avoid starting yaw when the blade forces are unbalanced, thereby preventing situations such as damage to the yaw motor and yaw gearbox.

[0048] The present invention also provides a load - reducing yaw control system for a wind turbine generator set to implement the load - reducing yaw control method for a wind turbine generator set described in any of the above - mentioned embodiments, including:

[0049] A data acquisition module, including fiber - Bragg - grating strain sensors. At least four of the fiber - Bragg - grating strain sensors are arranged at the root of each blade, which is used to measure the strain force of each blade of the wind turbine generator set after receiving a yaw start instruction, and make the data acquisition result more accurate through multi - point measurement;

[0050] A data processing module, which is used to calculate the influence quantization value of the strain force of each blade on the yaw load based on the strain force of each blade collected by the data acquisition module;

[0051] A condition determination module, which is used to make the following determinations based on the calculated influence quantization values of the three blades:

[0052] If the influence quantization value of only one blade exceeds the designed yaw limit of the blade, control the blade to feather until the influence quantization value of this blade is lower than the designed yaw limit of the blade and then resume normal control;

[0053] If the influence quantization values of at least two blades exceed the designed yaw limit of the blade, control the three blades of the unit to feather, and at the same time reduce the rotational speed and torque of the unit until the influence quantization values of the three blades are lower than the designed yaw limit of the blade and then resume normal control;

[0054] If the influence quantization values of the three blades are all lower than the designed yaw limit of the blade, start the yaw program.

[0055] The load - reducing yaw control system for a wind turbine generator set provided by the present invention installs several strain sensors at the root position of each blade, measures the unbalanced load of the blade before yaw start, determines the blade unbalance degree to complete the prediction calculation of the yaw load; then reduces the unbalanced load of the blade by changing the blade angle, and performs the yaw action when the yaw load is reduced to an appropriate value. Through the active control of the yaw load of the wind turbine generator in this way, the safe and stable yaw of the doubly - fed wind turbine generator set is realized.

[0056] The present invention also provides a computer - readable storage medium, on which an implementation program for information transmission is stored. When the program is executed by a processor, the steps of a load - reducing yaw control method for a wind turbine generator set described in any of the above - mentioned embodiments are realized.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A method for reducing load and yaw control of a wind turbine generator, characterized in that, Including the following steps: After receiving a yaw start command, measure the strain force of each blade of the wind turbine; Calculate the quantification value of the influence of the strain force of each blade on the yaw load; specifically, the following formula is used: Quantification value of the influence of blade 1: T1 = αsinθL1σ1m1n 2 Quantification value of the influence of blade 2: T2 = αsin(θ + 120°)L2σ2m2n 2 Quantification value of the influence of blade 3: T3 = αsin(θ - 120°)L3σ3m3n 2 Where α is a constant value obtained from the blade airfoil, θ is the zero position angle of the wind turbine, L is the length of the blade, σ is the stress value received at the blade root, m is the mass of the blade, and n is the angular velocity of the wind turbine rotation; Based on the calculated quantification values of the influence of the three blades, make the following judgments: If the quantification value of only one blade exceeds the designed yaw limit of the blade, control the blade to feather until the quantification value of this blade is lower than the designed yaw limit of the blade and then resume normal control; or If the quantification values of at least two blades exceed the designed yaw limit of the blade, control the three blades of the unit to feather, and at the same time reduce the rotational speed and torque of the unit until the quantification values of the three blades are lower than the designed yaw limit of the blade and then resume normal control; or If the quantification values of the three blades are all lower than the designed yaw limit of the blade, start the yaw program.

2. The yaw control method for reducing load of a wind turbine generator set according to claim 1, wherein, The measurement of the strain force of each blade of the wind turbine includes: At least four data acquisition points are set at the root of each blade to collect the acquisition data of each data acquisition point.

3. A load reduction yaw control system for a wind turbine generator, characterized in that, Including: A data acquisition module, configured to measure the strain force of each blade of the wind turbine after receiving a yaw start command; A data processing module, configured to calculate the quantification value of the influence of the strain force of each blade on the yaw load based on the strain force of each blade collected by the data acquisition module. Specifically, the following formula is used: Quantification value of the influence of blade 1: T1 = αsinθL1σ1m1n 2 Quantification value of the influence of blade 2: T2 = αsin(θ + 120°)L2σ2m2n 2 Quantification value of the influence of blade 3: T3 = αsin(θ - 120°)L3σ3m3n 2 Where α is a constant value obtained from the blade airfoil, θ is the zero position angle of the wind turbine, L is the length of the blade, σ is the stress value received at the blade root, m is the mass of the blade, and n is the angular velocity of the wind turbine rotation; A condition determination module, configured to make the following judgments based on the calculated quantification values of the influence of the three blades: If the quantification value of only one blade exceeds the designed yaw limit of the blade, control the blade to feather until the quantification value of this blade is lower than the designed yaw limit of the blade and then resume normal control; If the quantification values of at least two blades exceed the designed yaw limit of the blade, control the three blades of the unit to feather, and at the same time reduce the rotational speed and torque of the unit until the quantification values of the three blades are lower than the designed yaw limit of the blade and then resume normal control; If the quantification values of the three blades are all lower than the designed yaw limit of the blade, start the yaw program.

4. A yaw control system for reducing the load of a wind turbine generator set according to claim 3, characterized in that, The data acquisition module includes fiber Bragg grating strain sensors, and at least four of the fiber Bragg grating strain sensors are set at the root of each blade.

5. A computer-readable storage medium, characterized in that, An information transfer implementation program is stored on the computer-readable storage medium, and when the program is executed by a processor, the steps of a yaw control method for load reduction of a wind turbine generator set as described in any one of claims 1-2 are implemented.

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