Variable pitch control method, device, unit, medium and product for wind turbine generator

Abstract

The application discloses a variable pitch control method and device of a wind turbine generator set, the wind turbine generator set, a medium and a product, and belongs to the technical field of wind power generation. In the case that a variable pitch motor of the wind turbine generator set is in a brake holding state, a first wind speed of wind at a first position and a distance between the first position and a second position are acquired; a first time length required for the wind to reach the second position from the first position is determined according to the first wind speed and the distance; and the variable pitch motor of the wind turbine generator set is controlled according to the first wind speed before the first time length arrives, starting from timing when the wind reaches the first position. That is, the wind speed of the wind in front of the wind turbine generator set is acquired, and the variable pitch motor is controlled to release the brake in advance before the wind reaches the wind turbine generator set, so that the variable pitch motor can directly change the pitch when the wind reaches the wind turbine generator set, thereby reducing the delay time of the variable pitch and improving the response speed of the variable pitch.

Description

Technical Field

[0001] This application relates to the field of wind power generation technology, and in particular to a pitch control method, device, unit, medium and product for a wind turbine generator set. Background Technology

[0002] With the continuous increase in wind turbine capacity, ensuring efficient and stable operation of wind turbines and improving wind energy utilization has become an important aspect of wind power technology research. However, due to insufficient understanding of operating conditions and wind conditions, the operation of wind turbines still cannot meet the requirement of stable speed. This is because the current pitch control of wind turbines mainly uses proportional-integral-derivative (PID) control. In this method, the main control system uses maintaining a constant wind turbine speed as the control objective, calculates the pitch angle value, and transmits it to the pitch control system. The pitch control system then adjusts the pitch according to the latest angle command. While this method can achieve constant speed control to a certain extent, it also has the following drawbacks:

[0003] (1) Since wind speed is instantaneous, PID control alone has certain limitations in stabilizing the rotation speed.

[0004] (2) PID control is based on the target difference, that is, it only starts to calculate and adjust the pitch after detecting the change in the speed difference, which has a lag and affects the power generation of the unit.

[0005] Currently, some solutions aim to accelerate the response speed of the pitch control system by increasing the Kp value of the PID controller. However, an excessively large Kp value can easily lead to pitch oscillation and overshoot. Furthermore, the PID controller itself has a certain degree of lag, as its control principle is based on the difference between the target speed and the actual speed. Therefore, simply adjusting the parameters of the PID controller cannot completely solve the response speed problem of wind turbine pitch control. Summary of the Invention

[0006] This application provides a pitch control method, device, unit, medium, and product for wind turbine generator sets, which can effectively solve the problem of slow response speed when the pitch of wind turbine generator sets is changed.

[0007] In a first aspect, embodiments of this application provide a pitch control method for a wind turbine generator set, including:

[0008] With the pitch motor of the wind turbine generator set in a brake-on state, the first wind speed at the first position and the distance between the first position and the second position are obtained. The first position is the position in front of the wind turbine generator set facing the wind, and the second position is the position of the generator of the wind turbine generator set.

[0009] Based on the first wind speed and distance, determine the first time required for the wind to travel from the first location to the second location;

[0010] Timing begins when the wind reaches the first position. Before the first duration is reached, pitch control is applied to the pitch motor of the wind turbine based on the first wind speed.

[0011] Secondly, embodiments of this application provide a pitch control device for a wind turbine generator set, comprising:

[0012] The acquisition module is used to acquire the first wind speed at the first position and the distance between the first position and the second position when the pitch motor of the wind turbine generator is in the braked state. The first position is the position in front of the wind turbine generator in the upwind direction, and the second position is the position of the generator of the wind turbine generator.

[0013] The determination module is used to determine the first time required for the wind to travel from the first position to the second position based on the first wind speed and distance;

[0014] The control module is used to start timing from when the wind reaches the first position, and before the first duration is reached, to perform pitch control on the pitch motor of the wind turbine generator set according to the first wind speed.

[0015] Thirdly, embodiments of this application provide a wind turbine generator set, including:

[0016] processor;

[0017] Memory is used to store computer program instructions;

[0018] The lidar is used to measure the first wind speed at a first location and the distance between the first location and a second location, where the second location is the location of the generator of the wind turbine.

[0019] When computer program instructions are executed by the processor, the method described in the first aspect is implemented.

[0020] Fourthly, embodiments of this application provide a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, implement the method described in the first aspect.

[0021] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect.

[0022] In this embodiment, when the pitch motor of a wind turbine generator is in a brake-engaged state, a first wind speed at a first position and the distance between the first and second positions are obtained. The first position is a location facing the wind upstream in front of the wind turbine generator, and the second position is the location of the generator. Based on the first wind speed and distance, a first time interval required for the wind to travel from the first position to the second position is determined. Timing begins when the wind reaches the first position, and before the first time interval is reached, pitch control is applied to the pitch motor of the wind turbine generator based on the first wind speed. In other words, this embodiment obtains the wind speed in front of the generator and controls the pitch motor to release the brake before the wind reaches the generator, allowing the pitch motor to directly adjust the pitch upon the arrival of the wind. This reduces the pitch delay time and improves the pitch response speed. Attached Figure Description

[0023] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram of the operating area of ​​a wind turbine generator set, provided for related technologies;

[0025] Figure 2 A schematic diagram of the speed and power curves of a wind turbine generator set, provided for related technologies;

[0026] Figure 3 A schematic diagram of the structure of an electromagnetic brake for a pitch motor, provided for related technologies;

[0027] Figure 4 A timing diagram of pitch control provided for related technologies;

[0028] Figure 5 A schematic diagram of the hardware structure of a wind turbine generator set provided in this application embodiment;

[0029] Figure 6 A flowchart of a pitch control method for a wind turbine generator set provided in this application embodiment;

[0030] Figure 7 A flowchart of another pitch control method for a wind turbine generator set provided in this application embodiment;

[0031] Figure 8 A timing diagram of a pitch control provided for an embodiment of this application;

[0032] Figure 9 A schematic diagram of the relationship curve between wind speed and rotational speed provided in an embodiment of this application;

[0033] Figure 10 This is a schematic diagram of a pitch control process provided in an embodiment of this application;

[0034] Figure 11 A structural diagram of a pitch control device for a wind turbine generator set provided in this application embodiment;

[0035] Figure 12 This is a structural schematic diagram of a wind turbine generator set provided in an embodiment of this application. Detailed Implementation

[0036] The features and exemplary embodiments of various aspects of this application will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a comprehensive understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this application by illustrating examples. In the accompanying drawings and the following description, at least some well-known structures and techniques are not shown to avoid unnecessarily obscuring the application; and, for clarity, the dimensions of some structures may be exaggerated. Furthermore, the features, structures, or characteristics described below can be combined in any suitable manner in one or more embodiments.

[0037] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the cable-stayed tower and wind turbine generator set of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] Currently, the pitch control of wind turbine generators is mainly PID control. That is, the main control system uses the generator to run at a constant speed as the control target, calculates the corresponding pitch angle value and transmits it to the pitch control system, which then adjusts the pitch according to the pitch angle value.

[0039] Because wind speed is transient, PID control alone has limitations in stabilizing the rotational speed and exhibits a certain degree of lag. For example, when the wind speed suddenly increases, the generator speed may become too high. Excessive generator speed can easily trigger overspeed faults, causing the unit to shut down, and it can also increase the fatigue load on the unit. If the generator operates at a high speed for a long time, it will cause serious wear and tear on the unit and reduce its service life.

[0040] When the wind speed suddenly decreases, the unit is prone to frequently switching between the constant power range and the constant speed range: when the unit switches from the constant power range to the constant speed range, the torque value of the unit will decrease, which will lead to a decrease in power generation efficiency and affect the power generation of the unit.

[0041] like Figure 1 As shown, the operating range of a variable pitch wind turbine generator set is generally divided into four regions: the start-up zone 101, the constant wind energy utilization coefficient zone 102, the constant speed zone 103, and the constant power zone 104. Pitch adjustment of the wind turbine generator set typically affects the constant speed zone 103 and the constant power zone 104, i.e., the BD operating range. Pitch lag can easily cause unstable speed, which in turn leads to unstable power, affecting the generator's output and even causing overspeed faults at wind speeds above the rated speed.

[0042] Based on torque T1 = 9550P / n and Figure 1 At the critical point of pitch control, changes in engine speed affect power output. If pitch control is too slow, changes in wind speed will cause fluctuations in engine speed, leading to fluctuations in torque. Figure 2 As shown, curve 201 represents the speed value, and curve 202 represents the power value. Figure 2 As can be seen, the power output fluctuates significantly with the rotational speed, resulting in a loss of power generation. This fluctuation in rotational speed is caused by rapid changes in wind speed, which is due to untimely pitch adjustment. Combined with the rapid changes in wind speed, this results in a persistent lag in blade pitch control.

[0043] Although some solutions involve increasing the Kp value of the PID controller to speed up the pitch response, an excessively large Kp value can easily lead to pitch oscillation and overshoot. Furthermore, since the PID controller itself has a certain degree of lag, simply adjusting the parameters of the PID controller cannot completely solve the problem of the pitch response speed of the wind turbine generator.

[0044] In the above control schemes, a major factor affecting pitch speed is the solenoid valve release time. When the pitch motor releases the brake, the solenoid valve requires approximately 500ms to 1000ms to fully open, resulting in a slow start-up speed for the pitch system when pitch adjustment is needed. Since wind speed is transient, long-term, high-frequency pitch lag will inevitably affect the optimal tip speed ratio and rotational speed stability of the wind turbine, thus impacting the power generation of the wind turbine. Especially after prolonged operation of the wind turbine, aging and wear of the solenoid brake valve on the pitch motor will further prolong the release time.

[0045] Figure 3As shown, the electromagnetic brake of the pitch motor may include a brake disc 301, a brake flange 302, a brake armature 303, a fixing bolt 304, a motor shaft 305, a solenoid valve 306, a pressure spring 307, and a power supply cable 308. The function of each component can be found in the prior art, and will not be described in detail here for the sake of brevity.

[0046] The interaction between the electromagnetic force generated by the brake armature 303 and the elastic force of the pressure spring 307 enables the release and engagement functions of the electromagnetic brake. According to Newton's second law, the action and reaction forces between two interacting objects are always equal in magnitude, opposite in direction, and act along the same straight line. When the electromagnetic brake is energized and released, the elastic force of the pressure spring 307 and the electromagnetic force generated by the brake armature 303 reach equilibrium. According to Hooke's law, the elastic force generated by the pressure spring 307 (denoted as F1) is: F1 = fx, where f is the spring constant and x is the spring displacement. The magnitude of the force generated by the electromagnetic coil (denoted as F2) is: F2 = NI, where N is the number of turns of the electromagnetic coil and I is the operating current of the electromagnetic coil. According to Newton's third law, based on the above two formulas, we can obtain NI = fx. When the pitch motor is running, its force analysis is: (9550*p / n / R-fx)=ma, where 9550*p / n is the generator torque T1, R is the rotation radius of the motor shaft, and T1 / R is the magnitude of the force output by the motor.

[0047] When the solenoid valve 306 ages or wears out, the elastic force of the pressure spring 307 will decrease, resulting in a shorter release distance of the brake armature 303. This can lead to a stall in the pitch motor during operation. According to T1=9550*U*I / n, the increased resistance of the brake disc 301 will further delay the opening time of the solenoid valve 306, causing a further delay in the pitch start-up and response time of the wind turbine generator set, thus affecting the generator's power generation.

[0048] Figure 4 The diagram illustrates the timing of the existing scheme, with the horizontal axis representing time and the vertical axis representing the numerical values ​​of each data point. At time t1, the wind speed increases, causing the generator speed to rise. At time t2, the main controller detects the increased generator speed and issues a pitch control command. The pitch motor, receiving the command, begins to release the brake at time t3. The blades only begin to pitch after the solenoid valve fully opens at time t4. Therefore, the total pitch lag time is (t4-t1). While the impact of a single pitch response lag on wind turbine power generation may be small, since wind speed is constantly changing, statistics show that under medium-speed wind conditions, a single pitch control system can release and initiate pitch control up to 1800 times per day. As the number of turbines increases, its impact on power generation becomes significant.

[0049] To address the aforementioned issues, this application provides a pitch control method, device, unit, medium, and product for wind turbine generator sets, which can effectively solve the problem of slow response speed when the pitch of wind turbine generator sets is changed, thereby increasing the power generation of the unit.

[0050] Figure 5 This is a schematic diagram of the structure of a wind turbine generator set provided in an embodiment of this application, as shown below. Figure 5 As shown, the wind turbine generator set may include blades 501, hub 502, pitch control cabinet 503, pitch motor 504, nacelle 505, nacelle cabinet 506, and lidar 507.

[0051] Blade 501 is mounted on hub 502. LiDAR 507 is located on nacelle 505 and communicates with the main controller inside nacelle cabinet 506, transmitting the measured wind speed to the main controller. The main controller can be a Programmable Logic Controller (PLC).

[0052] The pitch control cabinet 503 houses a pitch controller and a pitch driver. The pitch controller communicates with the main controller in the nacelle cabinet 506 via a communication line. When the main controller detects a sudden change in wind speed, it can send a pitch command to the pitch controller. Upon receiving the pitch command, the pitch controller sends it to the pitch driver, which then drives the pitch motor 504 to perform the pitch operation.

[0053] The following is combined Figure 5 The present application describes the pitch control method, device, unit, medium and product of wind turbine generator set provided in the embodiments of this application with specific examples.

[0054] Figure 6 This is a flowchart illustrating a pitch control method for a wind turbine generator set, provided as an embodiment of this application. This pitch control method for a wind turbine generator set can be applied to the main controller. Figure 6 As shown, the pitch control method for this wind turbine generator set may include the following steps:

[0055] S610. When the pitch motor of the wind turbine generator is in the brake-holding state, obtain the first wind speed at the first position and the distance between the first position and the second position.

[0056] The first position is the location facing the wind and in front of the wind turbine generator set, while the second position is the location of the generator set's generator.

[0057] S620. Based on the first wind speed and distance, determine the first time required for the wind to travel from the first position to the second position.

[0058] S630: Starting from the moment the wind reaches the first position, before the first duration is reached, the pitch control of the wind turbine generator is performed according to the first wind speed.

[0059] In this embodiment, when the pitch motor of a wind turbine generator is in a brake-engaged state, a first wind speed at a first position and the distance between the first and second positions are obtained. The first position is a location facing the wind upstream in front of the wind turbine generator, and the second position is the location of the generator. Based on the first wind speed and distance, a first time interval required for the wind to travel from the first position to the second position is determined. Timing begins when the wind reaches the first position, and before the first time interval is reached, pitch control is applied to the pitch motor of the wind turbine generator based on the first wind speed. In other words, this embodiment obtains the wind speed in front of the generator and controls the pitch motor to release the brake before the wind reaches the generator, allowing the pitch motor to directly adjust the pitch upon the arrival of the wind. This reduces the pitch delay time and improves the pitch response speed.

[0060] The above steps are explained in detail below:

[0061] In S610, a pitch motor being in a braked state means that the pitch angle of the wind turbine remains unchanged for a certain period of time. For example, if the pitch angle of the wind turbine remains unchanged for 30 seconds, the pitch motor is considered to be in a braked state. The pitch angle here can be the pitch angle of any blade.

[0062] The first position can be a location facing upwards against the wind, in front of the turbine, i.e., a position away from the turbine. The first wind speed is the wind speed at the first position. For example, the wind speed at the first position can be obtained by measuring the wind speed at the first position using lidar. In this case, the first position can be a location within the lidar's scanning range. That is, in this embodiment of the application, the lidar can detect the wind speed in front of the turbine in advance, predict wind speed changes, and provide a basis for subsequent control of the pitch motor to adjust the pitch in advance. Facing upwards against the wind can be a direction away from the turbine, i.e., the first position is a location in front of the wind turbine, meaning there is a certain distance between the first position and the wind turbine.

[0063] The second position is the location of the generator set, which is also the location of the generator set itself. The distance between the first and second positions can be measured using lidar.

[0064] In this embodiment of the application, when the pitch motor is detected to be in a braked state, the forward wind speed of the unit and the distance between the forward position and the unit can be measured by lidar, so as to prepare for subsequent pitch control in advance, reduce pitch delay time, and improve pitch response speed.

[0065] In S620, for example, it can be assumed that the wind moves at a constant speed from the first position to the second position. Therefore, based on the ratio of the distance between the first position and the second position to the first wind speed, the time required for the wind to travel from the first position to the second position can be obtained, and this time can be determined as the first time.

[0066] For example, the reference time for the wind to travel from the first position to the second position can be obtained by assuming the wind moves at a constant speed, and the first time can be determined based on this reference time. For instance, considering that the wind may not be allowed to reach the second position in actual applications, in order to improve control accuracy, a certain time can be added to or subtracted from the reference time to obtain a time interval. The first time can be a value within this time interval or the time interval itself.

[0067] In S630, in order to improve the pitch response speed, for example, when the wind reaches the first position, a timer can be started to start timing. Before the timing duration is less than the first duration, that is, before the first duration is reached, the main controller can control the pitch motor according to the first wind speed.

[0068] Figure 7 A flowchart of another pitch control method for a wind turbine generator provided in this application embodiment. Figure 7 and Figure 6 The difference is that, Figure 6 The S630 in the text can be further refined into Figure 7 The S710-S720 series.

[0069] S710, when the first wind speed meets the preset condition and the timing duration reaches the second duration, the first pitch control is performed on the pitch motor, and the second duration is less than the first duration.

[0070] The preset conditions here can be conditions that characterize the change of the first wind speed. For example, the rated wind speed of the unit, the wind speed at the second position, and the rotational speed of the generator can be combined to determine whether the first wind speed has changed, and then determine whether the first wind speed meets the preset conditions. For example, when it is determined that the first wind speed has changed, it is considered that the first wind speed meets the preset conditions; otherwise, it is considered that the first wind speed does not meet the preset conditions.

[0071] The second duration can be set according to the scenario, needs, or experience. For example, the difference between the first duration and the second duration can be between 1 second and 2 seconds. For example, the second duration can be set to (Ta), where T is the first duration, a is the difference, and 1 < a < 2.

[0072] That is, in the embodiments of this application, when the timing duration reaches (Ta), the main controller can perform the first pitch control on the pitch motor.

[0073] In some embodiments, when the brake release is autonomously controlled by the pitch drive, the main controller may send a first pitch command to the pitch motor to cause the pitch motor to perform a first pitch operation. The first pitch command includes a first pitch speed, which is less than or equal to a preset speed threshold.

[0074] For example, the speed threshold can be set to 0.1° / s. In some embodiments, the first pitch speed can be set to 0.1° / s. That is, when the brake release is autonomously controlled by the pitch driver, the main controller can send the first pitch command to the pitch controller. After receiving the first pitch command, the pitch controller can forward it to the pitch driver, and the pitch driver controls the pitch motor to make micro-pitch changes at a speed of 0.1° / s.

[0075] In some embodiments, the first pitch speed can also be a sinusoidal speed command that is less than a speed threshold, that is, the pitch motor can perform micro-pitch by varying its speed.

[0076] For example, in addition to the first pitch speed, the first pitch command may also include a first enable signal, which is used to control the pitch motor to retract or extend the pitch.

[0077] In some embodiments, when the brake release is controlled by the main controller, a brake release command is sent to the pitch motor when the pitch motor speed is the target speed and the electromagnetic torque of the pitch motor is the target torque, so that the pitch motor performs the brake release operation.

[0078] For example, the target speed can be set to 0, and the target torque can be set to non-zero. That is, when the speed of the pitch motor is 0, but the electromagnetic torque is not 0, that is, when the pitch motor is held at 0 speed, the main controller can send a brake release command to the pitch motor to control the pitch motor to release the brake directly. In this way, blade slippage can be avoided.

[0079] In this embodiment of the application, different control strategies can be used to control the pitch motor to release the brake in advance before the timing duration reaches the second duration, thereby adapting to more working conditions and improving the flexibility of the method.

[0080] S720: When the timing duration reaches the first duration, perform a second pitch control on the pitch motor.

[0081] When the timing reaches the first duration, that is, when the wind reaches the unit, the main controller can control the pitch motor to perform the second pitch control.

[0082] For example, the main controller can obtain the generator's rated speed and actual speed;

[0083] The difference between the rated speed and the actual speed is processed by proportional-integral-differential to obtain the second pitch command. The second pitch command includes the second pitch speed, which is greater than a preset speed threshold.

[0084] Send a second pitch command to the pitch motor so that the pitch motor performs a second pitch operation.

[0085] The actual rotational speed here can be the generator speed when the wind reaches the unit. The main controller can calculate the difference between the generator's rated speed and the actual speed, and perform PID calculations on this difference to obtain the second pitch command. The specific calculation process will not be detailed here.

[0086] The second pitch command may include a second pitch speed, which is greater than a preset speed threshold, meaning the second pitch speed is greater than the first pitch speed. In addition to the second pitch speed, the second pitch command may also include a second enable signal, which may be the same as or different from the first enable signal.

[0087] Because the pitch motors are released before the wind reaches the turbine, the main controller can directly control them to operate at a higher pitch speed when the wind arrives. This reduces pitch delay time and improves pitch accuracy and response speed. Furthermore, timely pitch control enables stable generator speed control, reduces turbine vibration, and increases power generation.

[0088] Figure 8 A timing diagram of pitch control provided in an embodiment of this application is shown below. Figure 8 As shown, the horizontal axis represents time, and the vertical axis represents the numerical values ​​of each data point. Using lidar, the wind speed *v* at the first position in front of the generator and the distance *s* between the first position and the generator can be detected in advance. From this, the time it takes for the wind to travel from the first position to the second position can be calculated as *T* = *s* / *v*.

[0089] When the wind reaches the first position, a timer can be started. When the timer reaches (Ta), the main controller can control the pitch motor to release the brake early. At this time, the pitch motor either maintains zero speed or performs micro-pitching at a small speed. When the wind reaches the turbine, the main controller sends a second pitch command to the pitch motor. At this time, the pitch motor can pitch normally according to the pitch speed in the second pitch command. This significantly reduces the pitch delay time, improves the control accuracy and response speed of the pitch, and allows the impeller speed to be matched with the wind speed, improving the utilization rate of wind energy and thus increasing the power generation of the turbine. Here, t5 is the moment the wind speed at the first position is detected, t6 is the moment the pitch motor releases the brake, and t7 is the moment the pitch motor executes the second pitch command issued by the main controller.

[0090] Taking the determination of whether the wind speed at the first position meets the preset conditions based on the rated wind speed of the unit as an example, in some embodiments, before S710, the pitch control method of the wind turbine may further include the following steps:

[0091] Obtain the rated wind speed of the wind turbine generator set;

[0092] If the first wind speed is greater than the rated wind speed, it is determined that the first wind speed meets the preset conditions.

[0093] The rated wind speed of the unit can be the wind speed of the unit in unlimited power mode and unlimited speed mode. For example, when the first wind speed in front of the unit measured by the lidar is greater than the rated wind speed, the first wind speed is considered to meet the preset condition.

[0094] When the initial wind speed is greater than the rated wind speed, the generator speed will be greater than the rated speed as the wind force increases. In order to maintain the stable speed of the generator, the main controller can adjust the pitch angle through the pitch motor. That is, when the initial wind speed is greater than the rated wind speed, the main controller can control the pitch motor to retract the pitch to reduce the absorption of wind energy.

[0095] Taking the determination of whether the wind speed at the first location meets the preset conditions based on the wind speed at the turbine unit as an example, in some embodiments, before S710, the pitch control method of the wind turbine unit may further include the following steps:

[0096] Obtain the second wind speed at the second location;

[0097] If the difference between the first wind speed and the second wind speed is greater than the difference threshold, the first wind speed is determined to meet the preset condition.

[0098] The second wind speed is the wind speed at the second location, that is, the wind speed at the location of the generator unit. For example, the wind speed at the location of the generator unit can be measured by a wind speed sensor, which can be installed on the nacelle.

[0099] There can be one or more wind speed sensors. When there are multiple wind speed sensors, they can be set in different locations in the cabin. In this case, the average wind speed measured by multiple wind speed sensors can be used as the second wind speed.

[0100] The difference between the first wind speed and the second wind speed is greater than a threshold value, indicating that the first wind speed is greater than the second wind speed. When the difference between the first wind speed and the second wind speed is greater than the threshold value, that is, when the first wind speed is greater than the second wind speed, it can be determined that the first wind speed meets the preset condition. For example, the threshold value can be set to 2 meters per second, or it can be set to other values, which can be adjusted according to the scenario, requirements, etc.

[0101] The above scheme can be applied to situations where the unit is operating under limited power or limited speed. That is, when the unit is operating under limited power or limited speed, the wind speed in front of the unit can be determined based on the wind speed at the unit's location measured by the wind speed sensor, so as to provide a more accurate basis for subsequent pitch control.

[0102] Taking the determination of whether the wind speed at the first position meets the preset conditions based on the relationship between wind speed and rotational speed as an example, in some embodiments, before S710, the pitch control method of the wind turbine generator may further include the following steps:

[0103] Based on the first wind speed, find the wind speed-speed-rotation relationship to obtain the generator speed corresponding to the first wind speed. The wind speed-speed-rotation relationship includes the relationship between wind speed and generator speed.

[0104] If the generator speed is greater than the generator's rated speed, the first wind speed is determined to meet the preset conditions.

[0105] The relationship between wind speed and rotational speed can be a curve or a table. The relationship between wind speed and rotational speed can be obtained by statistically analyzing wind speed and the rotational speed of different units using big data.

[0106] Taking the relationship between wind speed and rotational speed as an example (using a curve), Figure 9 An exemplary diagram illustrating the relationship between wind speed and engine speed is provided, with the horizontal axis representing wind speed and the vertical axis representing generator speed. Here, 'a' represents the starting wind speed of the wind turbine, typically 3 m / s, and 'b' represents the rated wind speed of the wind turbine, typically 13 m / s.

[0107] Assuming the wind energy is W1, the rotational effect of the wind energy on the generator after grid connection is W3, the electromagnetic torque of the generator after grid connection is W4, and the energy offset by the unit, i.e., the energy that the wind energy fails to exert on the blade rotation direction, is W2. According to the principle of energy conservation, the energy conservation formula for the generator after grid connection is: W1 = W2 + W3 + W4. After the wind turbine reaches its rated speed, since the electromagnetic torque W4 is close to constant, the wind energy increases, which will increase W3. Therefore, it is necessary to perform pitch control in a timely manner to reduce wind energy absorption and maintain stable generator speed.

[0108] Based on the first wind speed, combined with Figure 9 The curve shown can be used to obtain the generator speed corresponding to the first wind speed.

[0109] Taking the relationship between wind speed and engine speed as an example, Table 1 lists some of the relationships between wind speed and engine speed. By looking up Table 1, the engine speed of the generator set corresponding to the first wind speed can be obtained.

[0110] Table 1

[0111] Serial Number Wind speed value Speed ​​value 1 v1 n1 2 v2 n2 3 v3 n3 4 v4 n4 5 v5 n5 6 v6 n6 7 v7 n7 8 v8 n8 9 v9 n9 10 v10 n10 11 v11 n11 12 v12 n12 13 v13 n13 14 v14 n14 15 v15 n15 16 v16 n16 17 v17 n17 18 v18 n18 19 v19 n19 20 v20 n20

[0112] When the generator speed corresponding to the first wind speed is greater than the generator's rated speed, it can be determined that the first wind speed meets the preset conditions.

[0113] For example, if the first wind speed measured by the lidar is v12, by looking up Table 1, the rotational speed corresponding to the wind speed value v12 can be determined to be n12. If this rotational speed is greater than the rated speed of the generator, then when the timing duration reaches (Ta), the pitch motor can be controlled to make a micro-pitch in advance, or the brake can be released directly. When the timing duration reaches T, the pitch motor can be controlled to make a normal pitch.

[0114] The embodiments of this application can predict the wind speed in front of the unit in different ways, providing a basis for subsequent pitch control, improving the flexibility of the prediction method, and making it applicable to different operating conditions.

[0115] Understandably, in practical applications, wind speed may suddenly decrease. In some embodiments, when the first wind speed is less than the wind speed measured by the wind speed sensor, or when the first wind speed is less than the rated wind speed, or when the generator speed corresponding to the first wind speed is less than the rated speed, the pitch motor can be controlled to start the pitch in time, thereby preventing the power generation from decreasing due to the excessive drop in speed.

[0116] The following is combined Figure 10 The pitch control process provided in the embodiments of this application will be described. It is assumed here that the pitch motor is currently in a brake-engaged state.

[0117] S1001. Set the brake release parameter a. a can usually be set to a value between 1 and 2.

[0118] S1002. Activate the lidar to measure the first wind speed at the first location and the distance between the first and second locations.

[0119] S1003. Based on the distance and the first wind speed, determine the first time T required for the wind to reach the unit, and start timing when the wind reaches the first position.

[0120] S1004. Does the first wind speed meet the preset conditions? If yes, then execute S1005; otherwise, return to execute S1004. Specifically, the first wind speed meets the preset conditions when it is greater than the rated wind speed, or when the difference between the first wind speed and the wind speed at the unit location (i.e., the second wind speed) is greater than the difference threshold, or when the generator speed corresponding to the first wind speed is greater than the rated speed.

[0121] S1005. Has the timeout period (Ta) been reached? If yes, then execute S1006; otherwise, return to execute S1005.

[0122] S1006, Send the first pitch command or brake release command to the pitch motor.

[0123] S1007: Has the timeout period reached T? If yes, then execute S1008; otherwise, return to execute S1007.

[0124] S1008, Send the second pitch command to the pitch motor.

[0125] This application embodiment predicts the wind speed ahead of the turbine in advance and controls the pitch motor to release the brakes in advance when pitch control is required, thereby reducing the pitch delay time and improving the pitch response speed of the wind turbine. At the same time, it can, to some extent, prevent gusts (sudden increases in wind speed), prevent generator overspeed, avoid triggering a turbine shutdown, maintain stable turbine speed, and improve the power generation performance of the wind turbine.

[0126] Furthermore, in the embodiments of this application, when performing pitch control, only the pitch motor needs to receive the pitch command, without the need for additional control or command triggering. The entire process is continuous and without interruption, and will not have an adverse effect on the control of the unit.

[0127] Based on the same inventive concept, this application also provides a pitch control device for a wind turbine generator set, which will be described below. Figure 11 The pitch control device for wind turbine generator sets provided in the embodiments of this application will be described in detail.

[0128] Figure 11 This is a structural diagram of a pitch control device for a wind turbine generator set provided in an embodiment of this application.

[0129] like Figure 11 As shown, the pitch control device 1100 of the wind turbine generator set may include:

[0130] The acquisition module 1101 is used to acquire the first wind speed at the first position and the distance between the first position and the second position when the pitch motor of the wind turbine generator is in the braked state. The first position is the position in front of the wind turbine generator in the upwind direction, and the second position is the position of the generator of the wind turbine generator.

[0131] The determining module 1102 is used to determine the first time required for the wind to travel from the first position to the second position based on the first wind speed and distance;

[0132] The control module 1103 is used to start timing from when the wind reaches the first position, and to perform pitch control on the pitch motor of the wind turbine generator set according to the first wind speed before the first duration is reached.

[0133] In this embodiment, when the pitch motor of a wind turbine generator is in a brake-engaged state, a first wind speed at a first position and the distance between the first and second positions are obtained. The first position is a location facing the wind upstream in front of the wind turbine generator, and the second position is the location of the generator. Based on the first wind speed and distance, a first time interval required for the wind to travel from the first position to the second position is determined. Timing begins when the wind reaches the first position, and before the first time interval is reached, pitch control is applied to the pitch motor of the wind turbine generator based on the first wind speed. In other words, this embodiment obtains the wind speed in front of the generator and controls the pitch motor to release the brake before the wind reaches the generator, allowing the pitch motor to directly adjust the pitch upon the arrival of the wind. This reduces the pitch delay time and improves the pitch response speed.

[0134] In some embodiments, the control module 1103 is specifically used for:

[0135] When the first wind speed meets the preset conditions and the timing duration reaches the second duration, the first pitch control is performed on the pitch motor, and the second duration is less than the first duration.

[0136] When the timing duration reaches the first duration, the pitch motor is subjected to a second pitch control.

[0137] In some embodiments, the control module 1103 is specifically used for:

[0138] A first pitch command is sent to the pitch motor to cause the pitch motor to perform a first pitch operation. The first pitch command includes a first pitch speed, which is less than or equal to a preset speed threshold.

[0139] In some embodiments, the control module 1103 is specifically used for:

[0140] When the pitch motor's speed is the target speed and the pitch motor's electromagnetic torque is the target torque, a brake release command is sent to the pitch motor to cause the pitch motor to perform a brake release operation.

[0141] In some embodiments, the acquisition module 1101 is further configured to acquire the rated speed and actual speed of the generator;

[0142] Control module 1103 is specifically used for:

[0143] The difference between the rated speed and the actual speed is processed by proportional-integral-differential to obtain the second pitch command. The second pitch command includes the second pitch speed, which is greater than a preset speed threshold.

[0144] Send a second pitch command to the pitch motor so that the pitch motor performs a second pitch operation.

[0145] In some embodiments, the acquisition module 1101 is further configured to acquire the rated wind speed of the wind turbine generator set before the control module 1103 performs the first pitch control on the pitch motor.

[0146] Module 1102 is specifically used for:

[0147] If the first wind speed is greater than the rated wind speed, it is determined that the first wind speed meets the preset conditions.

[0148] In some embodiments, the acquisition module 1101 is further configured to acquire the second wind speed at the second position before the control module 1103 performs the first pitch control on the pitch motor;

[0149] Module 1102 is specifically used for:

[0150] If the difference between the first wind speed and the second wind speed is greater than the difference threshold, the first wind speed is determined to meet the preset condition.

[0151] In some embodiments, the pitch control device 1100 of the wind turbine generator set may further include:

[0152] The lookup module is used to look up the wind speed-speed-rotation relationship based on the first wind speed to obtain the generator speed corresponding to the first wind speed. The wind speed-speed-rotation relationship includes the relationship between wind speed and generator speed.

[0153] Module 1102 is specifically used for:

[0154] If the generator speed is greater than the generator's rated speed, the first wind speed is determined to meet the preset conditions.

[0155] The pitch control device for wind turbine generator sets provided in this application embodiment can achieve… Figures 6-10 The various processes in the embodiment of the pitch control method for the wind turbine generator shown can achieve the same technical effect, and will not be described again here to avoid repetition.

[0156] Based on the same inventive concept, this application also provides a wind turbine generator set, such as... Figure 12 As shown, the wind turbine generator set 1200 may include a processor 1201, a memory 1202 for storing computer program instructions, and a lidar 1203 for measuring a first wind speed at a first location and the distance between the first location and a second location, wherein the second location is the location of the generator of the wind turbine generator set 1200.

[0157] Processor 1201 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that may be configured to implement the embodiments of this application.

[0158] Memory 1202 may include mass storage for data or instructions. For example, and not limitingly, memory 1202 may include a hard disk drive (HDD), a floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. In one instance, memory 1202 may include removable or non-removable (or fixed) media, or memory 1202 may be non-volatile solid-state memory. In one instance, memory 1202 may be read-only memory (ROM). In one instance, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM), or flash memory, or a combination of two or more of these.

[0159] The processor 1201 reads and executes computer program instructions stored in the memory 1202 to achieve... Figures 6-10 The method in the illustrated embodiment achieves... Figures 6-10 The corresponding technical effects achieved by the methods in the illustrated embodiments are described briefly and will not be elaborated further here.

[0160] In one example, the wind turbine generator 1200 may also include a communication interface 1204 and a bus 1205. Wherein, as... Figure 12 As shown, the processor 1201, memory 1202, lidar 1203, and communication interface 1204 are connected through bus 1205 and complete communication with each other.

[0161] The communication interface 1204 is mainly used to realize communication between various modules, devices and / or equipment in the embodiments of this application.

[0162] Bus 1205 includes hardware, software, or both, that couples the components of wind turbine generator 1200 together. For example, and not as a limitation, bus 1205 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 1205 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, this application contemplates any suitable bus or interconnect.

[0163] When the pitch motor of the wind turbine generator set 1200 is in a brake-locked state, after obtaining the first wind speed at the first position and the distance between the first and second positions, it can execute the pitch control method of the wind turbine generator set in this embodiment of the application, thereby achieving a combination of... Figures 6-10 The described pitch control method for wind turbine generator sets and Figure 11 The pitch control device for a wind turbine generator set is described.

[0164] Furthermore, in conjunction with the pitch control method for wind turbine generators in the above embodiments, this application embodiment can provide a computer storage medium for implementation. This computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the pitch control methods for wind turbine generators in the above embodiments.

[0165] Furthermore, in conjunction with the pitch control method for wind turbine generators in the above embodiments, this application embodiment can provide a computer program product to implement it. This computer program product includes a computer program that, when executed by a processor, implements any of the pitch control methods for wind turbine generators in the above embodiments.

[0166] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A pitch control method for a wind turbine generator set, characterized in that, include: When the pitch motor of the wind turbine generator set is in a brake-on state, the first wind speed at the first position and the distance between the first position and the second position are obtained. The first position is the position in front of the wind turbine generator set facing the wind, and the second position is the position of the generator of the wind turbine generator set. Based on the first wind speed and the distance, determine the first time required for the wind to travel from the first position to the second position; When the first wind speed meets the preset condition and the timing duration reaches the second duration, the first pitch control is performed on the pitch motor, where the second duration is less than the first duration. When the timing duration reaches the first duration, the pitch motor is subjected to a second pitch control.

2. The pitch control method according to claim 1, characterized in that, The first pitch control of the pitch motor includes: A first pitch command is sent to the pitch motor to cause the pitch motor to perform a first pitch operation. The first pitch command includes a first pitch speed, which is less than or equal to a preset speed threshold.

3. The pitch control method according to claim 1, characterized in that, The first pitch control of the pitch motor includes: When the speed of the pitch motor is the target speed and the electromagnetic torque of the pitch motor is the target torque, a brake release command is sent to the pitch motor to cause the pitch motor to perform a brake release operation.

4. The pitch control method according to claim 1, characterized in that, The second pitch control of the pitch motor includes: Obtain the rated speed and actual speed of the generator; The difference between the rated speed and the actual speed is processed by proportional-integral-differential (PID) to obtain a second pitch command. The second pitch command includes a second pitch speed, which is greater than a preset speed threshold. Send the second pitch command to the pitch motor so that the pitch motor performs the second pitch operation.

5. The pitch control method according to any one of claims 1-4, characterized in that, Before performing the first pitch control on the pitch motor, the method further includes: Obtain the rated wind speed of the wind turbine generator set; If the first wind speed is greater than the rated wind speed, it is determined that the first wind speed meets the preset conditions.

6. The pitch control method according to any one of claims 1-4, characterized in that, Before performing the first pitch control on the pitch motor, the method further includes: Obtain the second wind speed at the second location; If the difference between the first wind speed and the second wind speed is greater than a difference threshold, the first wind speed is determined to meet a preset condition.

7. The pitch control method according to any one of claims 1-4, characterized in that, Before performing the first pitch control on the pitch motor, the method further includes: Based on the first wind speed, the wind speed-speed-rotation relationship is found to obtain the generator speed corresponding to the first wind speed. The wind speed-speed-rotation relationship includes the relationship between wind speed and generator speed. If the generator speed is greater than the generator's rated speed, the first wind speed is determined to meet the preset condition.

8. A pitch control device for a wind turbine generator set, characterized in that, include: The acquisition module is used to acquire the first wind speed at a first position and the distance between the first position and the second position when the pitch motor of the wind turbine generator is in a brake-on state. The first position is a position in front of the wind turbine generator in the upwind direction, and the second position is the position of the generator of the wind turbine generator. The determining module is used to determine, based on the first wind speed and the distance, the first time required for the wind to travel from the first position to the second position; The control module is used to perform a first pitch control on the pitch motor when the first wind speed meets a preset condition and the timing duration reaches a second duration, wherein the second duration is less than the first duration; and to perform a second pitch control on the pitch motor when the timing duration reaches the first duration.

9. A wind turbine generator set, characterized in that, include: processor; Memory is used to store computer program instructions; A lidar is used to measure the first wind speed at a first location and the distance between the first location and a second location, where the second location is the location of the generator of the wind turbine generator set; When the computer program instructions are executed by the processor, the method as described in any one of claims 1-7 is implemented.

10. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the computer program instructions are executed by the processor, the method as described in any one of claims 1-7 is implemented.

11. A computer program product, characterized in that, It includes a computer program, which, when executed by a processor, implements the method as described in any one of claims 1-7.

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