Wind turbine yaw brake control method

Abstract

The application discloses a wind turbine yaw brake control method, which comprises the following steps: setting a wind-attacking angle threshold and an action delay time based on a yaw wind-attacking speed and a hydraulic station pressure establishing speed of a wind turbine; and performing yaw brake control of the wind turbine by starting the hydraulic station when an actual wind-attacking angle is below the wind-attacking angle threshold and starting an electromagnetic brake after the yaw motor is turned off and the action delay time elapses according to the wind-attacking angle threshold and the action delay time. The wind turbine yaw brake control method can ensure that the yaw brake can establish brake pressure and provide a certain brake torque after the yaw wind-attacking action of the wind turbine is completed, so that the wind turbine can be prevented from malfunctioning, and the electromagnetic brake can be prevented from bearing excessive brake torque, thereby ensuring the service life of the electromagnetic brake.

Description

Technical Field

[0001] This invention relates to the field of wind turbine technology, and in particular to a yaw braking control method for wind turbines. Background Technology

[0002] A wind turbine is a large-scale device that converts wind energy into electrical energy. It uses a rotating rotor to convert wind energy into mechanical energy, which is then converted back into electrical energy by a power generation system. With the continuous development of wind power technology, the application of wind turbines in power systems is increasing.

[0003] The yaw system is an essential component of wind turbines. It works in conjunction with the wind turbine's control system to ensure the turbine rotor is always facing the wind, thereby maximizing wind energy utilization and improving power generation efficiency. It also provides the necessary locking torque to ensure safe operation. Currently, the yaw brake in wind turbine yaw systems is a hydraulic brake. During operation, after the yaw action is completed and the yaw motor shuts down, a braking command is issued. At this point, the hydraulic station pressurizes, driving the yaw brake. Simultaneously, the electromagnetic brake installed under the yaw motor activates to brake the yaw motor.

[0004] However, in practical applications, the hydraulic station used in wind turbines typically pressurizes slowly. If the hydraulic station is pressurized only after the yaw action has been completed, the yaw brake may not be able to build up braking pressure in time to provide sufficient braking torque, leading to the following problems:

[0005] 1. When the yaw wind action is completed and the yaw motor is turned off, if the braking torque of the yaw brake is insufficient, it will not be able to hold the yaw base tightly. At this time, the instantaneous change of wind direction may cause yaw slip failure.

[0006] Second, if the yaw brake holding pressure is insufficient, and the electromagnetic brake installed under the yaw motor has been activated, the electromagnetic brake will be subjected to excessive braking torque, exceeding its rated design specifications, which may easily lead to damage to the electromagnetic brake and failure of the braking function.

[0007] Third, if the yaw brake pressure is insufficient when the yaw action stops, the connecting flange between the yaw brake and the yaw bearing will be continuously impacted, causing mechanical fatigue. Long-term operation may even lead to weld cracking, which will seriously damage the fan. Summary of the Invention

[0008] To address some or all of the technical problems existing in the prior art, the present invention provides a yaw braking control method for wind turbine generators.

[0009] The technical solution of the present invention is as follows:

[0010] A yaw braking control method for a wind turbine is provided, comprising:

[0011] Based on the yaw speed of the wind turbine and the speed at which the hydraulic station builds up pressure, set the wind angle threshold and the action delay time.

[0012] Based on the wind angle threshold and the action delay time, the yaw braking control of the wind turbine is carried out by activating the hydraulic station when the actual wind angle reaches below the wind angle threshold and activating the electromagnetic brake after the action delay time after the yaw motor is turned off.

[0013] In some possible implementations, based on the yaw speed of the wind turbine and the speed at which the hydraulic station builds up pressure, a wind angle threshold and an action delay time are set, further including:

[0014] Based on the yaw speed of the wind turbine, a pre-set threshold for the wind angle is established.

[0015] Based on the speed at which the hydraulic station builds up pressure and the wind angle threshold, an action delay time is set so that the hydraulic station can reach the pressure level that provides effective braking torque when the electromagnetic brake is activated.

[0016] In some possible implementations, the wind angle threshold satisfies the following condition:

[0017]

[0018] Where σ represents the wind angle threshold, v yaw P1 represents the yaw speed against the wind, P0 represents the pressure level at which the hydraulic station can just provide effective braking torque, and v represents the initial pressure when the hydraulic station starts to pressurize. hro This indicates the speed at which the hydraulic station builds up pressure.

[0019] In some possible implementations, the delay time of the action is determined using the following formula:

[0020]

[0021] Where t0 represents the action delay time.

[0022] In some possible implementations, the yaw braking control of the wind turbine is achieved by activating the hydraulic station when the actual wind angle reaches below the wind angle threshold, and by activating the electromagnetic brake after a delay following the shutdown of the yaw motor. Further implementations include:

[0023] The actual windward angle of the wind turbine is acquired in real time, and it is determined whether the actual windward angle is less than or equal to the windward angle threshold. If so, proceed to the next step.

[0024] Start the hydraulic station to increase the pressure;

[0025] The actual wind angle of the wind turbine is obtained in real time, and it is determined whether the actual wind angle is greater than the first preset angle and whether the actual wind angle is less than or equal to the second preset angle. If the actual wind angle is greater than the first preset angle, the hydraulic station is depressurized and the process returns to step one. If the actual wind angle is less than or equal to the second preset angle, the process proceeds to step one.

[0026] Continue pressurizing the hydraulic station until it reaches full pressure, while simultaneously shutting off the yaw motor and activating the electromagnetic brake after the action delay time.

[0027] In some possible implementations, the actual wind angle is determined using the following formula:

[0028] Actual wind angle = |Current wind direction - Cabin nose direction|.

[0029] In some possible implementations, the first preset angle is a wind angle threshold.

[0030] In some possible implementations, the second preset angle is 0.

[0031] The main advantages of the technical solution of this invention are as follows:

[0032] The yaw braking control method for wind turbines of the present invention sets a windward angle threshold and an action delay time based on the yaw windward speed of the wind turbine and the pressure build-up speed of the hydraulic station. This allows the hydraulic station to be started in advance to increase pressure before the yaw action is completed, and the electromagnetic brake to be started after the yaw motor is turned off for a period of time. This ensures that the yaw brake can build up braking pressure and provide a certain braking torque after the yaw windward action of the wind turbine is completed, thus avoiding wind turbine failure. At the same time, it can also prevent the electromagnetic brake from bearing excessive braking torque, thus ensuring the service life of the electromagnetic brake. Attached Figure Description

[0033] The accompanying drawings, which are provided to further illustrate embodiments of the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions serve to explain the invention, but do not constitute an undue limitation of the invention.

[0034] In the picture:

[0035] Figure 1 This is a flowchart of a wind turbine yaw braking control method according to an embodiment of the present invention;

[0036] Figure 2 This is a flowchart illustrating a specific process of yaw braking control according to an embodiment of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0038] The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0039] refer to Figure 1 An embodiment of the present invention provides a yaw braking control method for wind turbine generators, the method comprising the following steps:

[0040] Step S1: Based on the yaw speed of the wind turbine and the speed at which the hydraulic station builds up pressure, set the wind angle threshold and the action delay time.

[0041] Step S2: Based on the wind angle threshold and the action delay time, the yaw braking control of the wind turbine is performed by starting the hydraulic station when the actual wind angle reaches below the wind angle threshold and starting the electromagnetic brake after the action delay time after the yaw motor is turned off.

[0042] The yaw braking control method for wind turbines provided in one embodiment of the present invention sets a windward angle threshold and an action delay time based on the yaw windward speed of the wind turbine and the pressure build-up speed of the hydraulic station. This allows the hydraulic station to be started in advance to increase pressure before the yaw action is completed, and the electromagnetic brake to be started after the yaw motor is turned off for a period of time. This ensures that the yaw brake can build up braking pressure and provide a certain braking torque after the yaw windward action of the wind turbine is completed, thus avoiding wind turbine failure. At the same time, it can also prevent the electromagnetic brake from bearing excessive braking torque, thus ensuring the service life of the electromagnetic brake.

[0043] In one embodiment of the present invention, based on the yaw speed of the wind turbine and the pressure build-up speed of the hydraulic station, a wind angle threshold and an action delay time are set, and the invention further includes the following steps:

[0044] Step S11: Based on the yaw speed of the wind turbine, a wind angle threshold is preset;

[0045] Step S12: Based on the speed at which the hydraulic station builds up pressure and the wind angle threshold, set the action delay time so that the hydraulic station can reach the pressure level that provides effective braking torque when the electromagnetic brake is activated.

[0046] In one embodiment of the present invention, the wind angle threshold is specifically set based on the yaw speed of the wind turbine and the actual situation, while satisfying the following conditions:

[0047]

[0048] Where σ represents the wind angle threshold, v yaw P1 represents the yaw speed against the wind, P0 represents the pressure level at which the hydraulic station can just provide effective braking torque, and v represents the initial pressure when the hydraulic station starts to pressurize. hro This indicates the speed at which the hydraulic station builds up pressure.

[0049] Furthermore, the action delay time is determined using the following formula:

[0050]

[0051] Where t0 represents the action delay time.

[0052] For example, taking the design of the yaw speed and the pressure build-up speed of a hydraulic station for a 2MW wind turbine as an example, its yaw speed v yaw =0.3rad / s, the initial pressure of the hydraulic station at the start of pressurization is P0 = 30bar, the pressure level when effective braking torque is provided is P1 = 80bar, and the rate of pressure buildup is v. hro =8 bar / s. At this time, the wind angle threshold σ can be taken as 1.5°, and the corresponding action delay time t0 is calculated as 1.25s.

[0053] Further, refer to Figure 2 In one embodiment of the present invention, the yaw braking control of the wind turbine is performed by activating the hydraulic station when the actual wind angle reaches below the wind angle threshold and activating the electromagnetic brake after a delay time following the shutdown of the yaw motor. The method further includes the following steps:

[0054] Step S21: Obtain the actual wind angle of the wind turbine in real time, and determine whether the actual wind angle is less than or equal to the wind angle threshold. If so, proceed to the next step.

[0055] Step S22: Start the hydraulic station to increase the pressure;

[0056] Step S23: Obtain the actual wind angle of the wind turbine in real time, and determine whether the actual wind angle is greater than the first preset angle and whether the actual wind angle is less than or equal to the second preset angle. If the actual wind angle is greater than the first preset angle, depressurize the hydraulic station and return to step S21. If the actual wind angle is less than or equal to the second preset angle, proceed to the next step.

[0057] Step S24: Continue to pressurize the hydraulic station until it reaches full pressure, while shutting off the yaw motor and activating the electromagnetic brake after the action delay time.

[0058] By implementing the above-mentioned method for yaw braking control of wind turbines, it is possible to ensure that after the wind turbine completes its yaw action against the wind, the yaw brake can establish braking pressure and provide sufficient braking torque to prevent wind turbine failure. At the same time, it can also prevent the electromagnetic brake from being subjected to excessive braking torque, thus ensuring the service life of the electromagnetic brake.

[0059] In one embodiment of the present invention, the actual wind angle is determined using the following formula:

[0060] Actual wind angle = |Current wind direction - Cabin nose direction|.

[0061] The current wind direction can be measured using an anemometer installed on the wind turbine, while the direction of the nacelle and the turbine's nose can be obtained from the control data of the wind turbine's control system.

[0062] Furthermore, the first preset angle is used to determine whether the wind direction in the environment where the wind turbine is located has changed. The first preset angle is set according to the actual situation. In one embodiment of the present invention, the first preset angle is taken as the wind angle threshold. In step S23, if the actual wind angle is greater than the first preset angle, it indicates that the wind direction in the environment where the wind turbine is located has changed. At this time, it is necessary to depressurize the hydraulic station and return to step S21 to re-detect and judge the actual wind angle of the wind turbine until the actual wind angle is less than or equal to the wind angle threshold.

[0063] Furthermore, the second preset angle is used to determine whether the wind turbine has completed yaw. The second preset angle is set according to the actual situation, for example, it can be set to 0, 0.1, etc. In one embodiment of the present invention, the second preset angle is set to 0 to ensure that the wind turbine is facing the wind after yaw braking.

[0064] Furthermore, for ease of control, this yaw control method can be implemented through the wind turbine's control system.

[0065] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Additionally, the terms "front," "back," "left," "right," "upper," and "lower" in this document refer to the placement shown in the accompanying drawings.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A yaw braking control method for a wind turbine generator, characterized in that, include: Based on the yaw speed of the wind turbine and the speed at which the hydraulic station builds up pressure, set the wind angle threshold and the action delay time. Based on the wind angle threshold and the action delay time, the yaw braking control of the wind turbine is carried out by starting the hydraulic station when the actual wind angle reaches below the wind angle threshold and starting the electromagnetic brake after the action delay time after the yaw motor is turned off. The yaw braking control of the wind turbine unit adopts a method of activating the hydraulic station when the actual wind angle reaches below the wind angle threshold, and activating the electromagnetic brake after a delay time following the shutdown of the yaw motor, further including: The actual windward angle of the wind turbine is acquired in real time, and it is determined whether the actual windward angle is less than or equal to the windward angle threshold. If so, proceed to the next step. Start the hydraulic station to increase the pressure; The actual wind angle of the wind turbine is obtained in real time, and it is determined whether the actual wind angle is greater than the first preset angle and whether the actual wind angle is less than or equal to the second preset angle. If the actual wind angle is greater than the first preset angle, the hydraulic station is depressurized and the process returns to step one. If the actual wind angle is less than or equal to the second preset angle, the process proceeds to step one. Continue pressurizing the hydraulic station until it reaches full pressure, while simultaneously shutting off the yaw motor and activating the electromagnetic brake after the action delay time.

2. The wind turbine yaw braking control method according to claim 1, characterized in that, Based on the yaw speed of the wind turbine and the pressure build-up speed of the hydraulic station, the wind angle threshold and action delay time are set, further including: Based on the yaw speed of the wind turbine, a pre-set threshold for the wind angle is established. Based on the speed at which the hydraulic station builds up pressure and the wind angle threshold, an action delay time is set so that the hydraulic station can reach the pressure level that provides effective braking torque when the electromagnetic brake is activated.

3. The wind turbine yaw braking control method according to claim 2, characterized in that, The windward angle threshold satisfies the following condition: ； in, Indicates the threshold for wind angle. Indicates the yaw speed against the wind. This indicates that the hydraulic station is at the pressure level that can just provide effective braking torque. This indicates the initial pressure when the hydraulic station begins to pressurize. This indicates the speed at which the hydraulic station builds up pressure.

4. The wind turbine yaw braking control method according to claim 3, characterized in that, The delay time of the action is determined using the following formula: ； in, Indicates the time delay of an action.

5. The wind turbine yaw braking control method according to claim 1, characterized in that, The actual windward angle is determined using the following formula: Actual wind angle = |Current wind direction - Cabin nose direction|.

6. The yaw braking control method for wind turbine generators according to claim 1, characterized in that, The first preset angle is the wind angle threshold.

7. The yaw braking control method for wind turbine generators according to claim 1, characterized in that, The second preset angle is 0.

Images