Gear shaft structure, wind turbine and wind turbine protection control method

Abstract

The application relates to the technical field of wind power generation, in particular to a gear shaft structure, a wind driven generator and a wind driven generator protection control method. The gear shaft structure comprises an output shaft, a rotating gear and a friction plate assembly; the output shaft is provided with a transmission part, the rotating gear is provided with a transmission cavity, the output shaft is rotatably connected with the rotating gear, and the transmission part is accommodated in the transmission cavity; the friction plate assembly comprises a cylindrical friction plate, the cylindrical friction plate is sleeved on the transmission part and is in contact with the inner peripheral wall of the transmission cavity, so that a friction force is generated between the outer peripheral surface of the transmission part, the inner peripheral wall of the transmission cavity and the cylindrical friction plate, the transmission part and the transmission cavity are transmission connected, and the gear shaft structure can play a role in transmitting torque through the setting of the friction plate assembly. When the load exceeds a preset torque value, the relative sliding between the output shaft and the rotating gear can be realized, so that the gear set is protected.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and more specifically, to a gear shaft structure, a wind turbine generator, and a wind turbine generator protection and control method. Background Technology

[0002] The yaw system of a wind turbine generator mainly consists of a yaw bearing, a yaw main brake, a yaw motor, and a yaw gearbox. The inner ring of the yaw bearing is connected to the tower, and the outer ring is connected to the nacelle. The yaw motor provides yaw power, and the yaw gearbox converts the high-speed, low-torque output of the yaw motor into low-speed, high-torque rotational motion. The yaw gearbox is connected to the nacelle floor, and the rotation of the entire nacelle is driven by the meshing of the output shaft gear with the inner gear ring of the yaw bearing. When the wind turbine needs to generate electricity from the wind, the output shaft gear meshes with the large gear of the gear ring. The engagement and high-pressure brake lock the nacelle rotation. Due to the unpredictability of wind speed and direction, the wind turbine blades and turbine head are affected by sudden impact loads such as turbulence. When the load exceeds the limit load of the output shaft gear or yaw gearbox, the output shaft gear may break or the planetary carrier inside the gearbox may break. Alternatively, when the wind turbine is yawing normally, the wind speed and direction may suddenly change, and the sudden impact load on the turbine head may be transmitted to the output shaft gear of the yaw gearbox, causing the output shaft gear to break or the gearbox to be damaged by impact.

[0003] For the reasons mentioned above, in the existing technology, the output shaft gear is formed by integral forging of forged steel or the output shaft and gear are designed separately and connected by splines. However, the existing designs are all purely rigid designs and do not provide buffer protection for the yaw system. When extreme loads occur, exceeding the design margin of the gearbox, the output shaft gear may break or the planetary carrier inside the yaw gearbox may break, failing to protect the yaw gearbox from damage.

[0004] In addition, there are currently solutions to add torque limiters to yaw gearboxes. Since damage to yaw gearboxes often occurs at the output end, and the transmission ratio of yaw gearboxes is around 2000, instantaneous impact loads cannot be quickly transmitted to the input end of the gearbox through the planetary gears. Therefore, torque limiters cannot protect the gearbox from damage. Furthermore, if the torque limiter is added to the output end of the gearbox, the layout space at the output end is limited, and the torque limiter cannot be installed independently. Summary of the Invention

[0005] The objectives of this invention include, for example, providing a gear shaft structure, a wind turbine generator, and a wind turbine generator protection and control method, which can transmit torque through the setting of friction plate components, and can protect the gear set by relative sliding between the output shaft and the rotating gear when the load exceeds a preset torque value; in addition, its structure is simple, and it is easy to adjust the maximum load that can be carried, thereby improving its adaptability and reducing the structural size.

[0006] The embodiments of the present invention can be implemented as follows:

[0007] In a first aspect, the present invention provides a gear shaft structure, which includes an output shaft, a rotating gear, and a friction plate assembly;

[0008] The output shaft is equipped with a transmission part, the rotating gear is equipped with a transmission cavity, the output shaft and the rotating gear are rotatably connected, and the transmission part is housed in the transmission cavity;

[0009] The friction plate assembly includes a cylindrical friction plate, which is sleeved on the transmission part and contacts the inner peripheral wall of the transmission cavity, thereby generating friction between the transmission part and the transmission cavity through the outer peripheral surface of the transmission part and the inner peripheral wall of the transmission cavity.

[0010] In an optional embodiment, the friction plate assembly includes a pressure plate and a first annular friction plate; the pressure plate is connected to a rotating gear via multiple connecting bolts, the first annular friction plate is connected to a transmission unit, and the pressure plate presses against the first annular friction plate.

[0011] In an optional embodiment, the friction plate assembly further includes a plurality of disc springs, each disc spring being fitted onto a connecting bolt and abutting against the pressure plate, so that the pressure plate has a tendency to move toward the first annular friction plate.

[0012] In an optional embodiment, a connecting boss is provided on the outer peripheral surface of the transmission part, and a first connecting surface and a second connecting surface are respectively provided at both ends of the connecting boss along the axial direction of the output shaft.

[0013] The friction plate assembly also includes a second annular friction plate, wherein the first annular friction plate is connected to the first connecting surface, and the second annular friction plate is connected to the second connecting surface;

[0014] The second annular friction plate is in contact with the inner wall of the transmission cavity.

[0015] In an optional embodiment, a cylindrical friction pad is fitted onto the connecting boss.

[0016] In an optional embodiment, the inner wall of the transmission cavity is provided with a first annular cavity and a second annular cavity, the first annular cavity and the second annular cavity are connected, and the inner diameter of the first annular cavity is smaller than the inner diameter of the second annular cavity. A stepped surface is formed at the connection between the first annular cavity and the second annular cavity.

[0017] The connecting boss is housed in the first annular cavity, and the clamping plate is housed in the second annular cavity; the connecting bolt is connected to the stepped surface, and the clamping plate is used to hold the surface of the first annular friction plate at a distance from the stepped surface.

[0018] In a second aspect, the present invention provides a wind turbine generator, which includes a tower, a nacelle, a yaw bearing, a yaw motor and a yaw gearbox.

[0019] The nacelle and the tower are rotatably connected; the inner ring of the yaw bearing is connected to the tower, and the outer ring of the yaw bearing is connected to the nacelle; the yaw gearbox is connected to the nacelle, and the yaw gearbox includes the aforementioned gear shaft structure, the output shaft is connected to the yaw motor drive, and the rotating gear meshes with the yaw bearing.

[0020] Thirdly, the present invention provides a wind turbine protection and control method, implemented using the aforementioned wind turbine, comprising:

[0021] Collect the engine speed N1 and the yaw motor speed N2; determine whether the engine speed N1 multiplied by the transmission ratio i of the yaw gearbox is equal to the yaw motor speed N2;

[0022] The wind turbine operates normally when the speed N1 of the nacelle multiplied by the transmission ratio i of the yaw gearbox equals the speed N2 of the yaw motor.

[0023] If the speed of the nacelle N1 multiplied by the transmission ratio i of the yaw gearbox is not equal to the speed of the yaw motor N2, determine whether the speed of the yaw motor N2 is equal to 0.

[0024] When the yaw motor speed N2 is equal to 0 and the nacelle speed N1 is not equal to 0, adjust the working state of the wind turbine blades and the operating power of the wind turbine.

[0025] If the yaw motor speed N2 is not equal to 0, then control all blades to retract, stop the yaw drive, and allow the wind turbine to enter standby mode.

[0026] In an optional implementation, the steps of adjusting the operating state of the wind turbine blades and the operating power of the wind turbine include:

[0027] Control the blade section of the wind turbine to retract and cause the wind turbine to operate at limited power.

[0028] Based on meteorological station data, determine whether there will be a sudden change in wind conditions within a preset time period. If there is, continue to operate with limited power. If there is no sudden change in wind conditions, control the blades to deploy and the wind turbine to operate at full power.

[0029] In an optional implementation, after the wind turbine enters standby mode, the wind turbine protection control method further includes the following steps:

[0030] Determine whether the engine nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox is equal to the yaw motor speed N2;

[0031] If the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox is not equal to the yaw motor speed N2, then the wind turbine will be controlled to issue an alarm shutdown and maintenance signal.

[0032] When the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox equals the yaw motor speed N2, the wind turbine can restart the yaw system.

[0033] The beneficial effects of the embodiments of the present invention include:

[0034] This gear shaft structure includes an output shaft, a rotating gear, and a friction plate assembly. The output shaft is equipped with a transmission part, and the rotating gear is equipped with a transmission cavity. The output shaft and the rotating gear are rotatably connected, and the transmission part is housed within the transmission cavity. The friction plate assembly includes a cylindrical friction plate, which is sleeved on the transmission part and contacts the inner peripheral wall of the transmission cavity. This generates friction between the outer peripheral surface of the transmission part and the inner peripheral wall of the transmission cavity, thereby connecting the transmission part and the transmission cavity. Through the friction plate assembly, this gear shaft structure can transmit torque. When the load exceeds a preset torque value, the relative sliding between the output shaft and the rotating gear protects the gear set. Furthermore, its simple structure allows for easy adjustment of the maximum load capacity, improving its adaptability and reducing structural size. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the gear shaft structure from a first-view perspective in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the gear shaft structure from a second perspective in an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the gear shaft structure from a third-view perspective in an embodiment of the present invention;

[0039] Figure 4 This is a cross-sectional view of the gear shaft structure in an embodiment of the present invention;

[0040] Figure 5 This is a flowchart of the wind turbine protection and control method in an embodiment of the present invention.

[0041] Icons: 100-Gear shaft structure; 110-Output shaft; 120-Rotating gear; 130-Friction plate assembly; 111-Transmission part; 121-Transmission cavity; 131-Cylindrical friction plate; 132-Pressure plate; 133-First annular friction plate; 134-Disc spring; 112-Connecting boss; 135-Second annular friction plate; 122-First annular cavity; 123-Second annular cavity; 124-Stepped surface. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0045] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0046] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0047] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0048] Please refer to Figures 1-4 This embodiment provides a gear shaft structure 100, which includes an output shaft 110, a rotating gear 120, and a friction plate assembly 130.

[0049] The output shaft 110 is equipped with a transmission part 111, and the rotating gear 120 is equipped with a transmission cavity 121. The output shaft 110 and the rotating gear 120 are rotatably connected, and the transmission part 111 is housed in the transmission cavity 121.

[0050] The friction plate assembly 130 includes a cylindrical friction plate 131, which is sleeved on the transmission part 111 and contacts the inner peripheral wall of the transmission cavity 121, thereby generating friction between the outer peripheral surface of the transmission part 111 and the inner peripheral wall of the transmission cavity 121 to drive and connect the transmission part 111 and the transmission cavity 121.

[0051] Among them, the cylindrical friction plate 131 is interference-fitted with the transmission part 111; in addition, the coupling surfaces of the output shaft 110 and the rotating gear 120 with the friction plate assembly 130 are all hardened to a hardness of HRC55 or higher and a surface roughness of Ra1.6.

[0052] Please refer to Figures 1-4 The working principle of the gear shaft structure 100 is as follows:

[0053] The gear shaft structure 100 includes an output shaft 110, a rotating gear 120, and a friction plate assembly 130. The output shaft 110 is equipped with a transmission part 111, and the rotating gear 120 is equipped with a transmission cavity 121. The output shaft 110 and the rotating gear 120 are rotatably connected, and the transmission part 111 is housed in the transmission cavity 121. The friction plate assembly 130 includes a cylindrical friction plate 131, which is sleeved on the transmission part 111 and contacts the inner peripheral wall of the transmission cavity 121, thereby generating friction between the outer peripheral surface of the transmission part 111 and the inner peripheral wall of the transmission cavity 121 to drive and connect the transmission part 111 and the transmission cavity 121.

[0054] It should be noted that the gear shaft structure 100 is used in the yaw gearbox of the wind turbine. It is used to transmit power from the yaw motor to the yaw bearing during the yaw motion of the wind turbine, thereby driving the nacelle to yaw relative to the tower. Thus, during this process, there is a power transmission between the output shaft 110 and the rotating gear 120. In the process of transmitting power, the gear shaft structure 100 can transmit the torque received by the output shaft 110 to the rotating gear 120 through the friction between the friction plate assembly 130 and the rotating gear 120 and the output shaft 110, thereby driving the nacelle to rotate.

[0055] This torque transmission method allows for adjustment of the transmittable torque through the friction between the cylindrical friction plate 131 of the friction plate assembly 130 and the rotating gear 120 and output shaft 110. Therefore, when the transmitted torque is within the transmittable range, the output shaft 110 and the rotating gear 120 are in a normal transmission state. However, when the transmitted torque exceeds the transmittable range, because the transmitted torque is greater than the frictional torque between the friction plate assembly 130 and the rotating gear 120 and the output shaft 110, a torque-dependent frictional force is generated between the output shaft 110 and the rotating gear 120. When rotating, the cylindrical friction plate 131 slides relative to the rotating gear 120 or the output shaft 110. Thus, through this arrangement, the output shaft 110, rotating gear 120, and friction plate assembly 130 can transmit torque while protecting the gear shaft structure 100 and the yaw gearbox. In addition, the gear shaft structure 100 has the advantage of simple structure, and the maximum load that can be carried can be adjusted by adjusting the structure of the friction plate assembly 130, thereby improving its adaptability and reducing the structural size.

[0056] Further, please refer to Figures 1-4In this embodiment, when configuring the friction plate assembly 130, the friction plate assembly 130 may include a pressure plate 132 and a first annular friction plate 133; wherein, the pressure plate 132 is connected to the rotating gear 120 by a plurality of connecting bolts, the first annular friction plate 133 is connected to the transmission part 111, and the pressure plate 132 presses the first annular friction plate 133. Thus, in this way, the first annular friction plate 133 can be connected to the transmission part 111 by countersunk screws, and under the pressing action of the clamping plate 132 connected to the rotating gear 120, the rotating gear 120 and the output shaft 110 are kept in the assembled state. At the same time, the pressing action of the clamping plate 132 on the first annular friction plate 133 can also generate a corresponding friction force between the clamping plate 132 and the first annular friction plate 133, thereby playing the same role as the cylindrical friction plate 131 mentioned above, thereby improving the protection capability of the gear shaft structure 100 and the yaw gearbox. In addition, with the clamping plate 132 configured, the magnitude of the generated friction force can be further adjusted during use, thereby adjusting the limit value of the friction force between the rotating gear 120 and the output shaft 110, thereby improving the applicability of the gear shaft structure 100.

[0057] Based on the above structure, in order to facilitate the adjustment of the pressing force of the pressing plate 132 on the first annular friction plate 133, the friction plate assembly 130 also includes a plurality of disc springs 134. Each disc spring 134 is correspondingly sleeved on a connecting bolt and abuts against the pressing plate 132, so that the pressing plate 132 has a tendency to move toward the first annular friction plate 133.

[0058] Further, please refer to Figures 1-4 In this embodiment, to facilitate the assembly of the rotating gear 120 and the output shaft 110, a connecting boss 112 is provided on the outer peripheral surface of the transmission part 111. Furthermore, a first connecting surface and a second connecting surface are respectively provided at both ends of the connecting boss 112 along the axial direction of the output shaft 110. Based on this, the friction plate assembly 130 also includes a second annular friction plate 135. The first annular friction plate 133 is connected to the first connecting surface, and the second annular friction plate 135 is connected to the second connecting surface. The second annular friction plate 135 contacts the inner wall of the transmission cavity 121. Thus, through this arrangement, friction is generated by the contact between the second annular friction plate 135 and the inner wall of the transmission cavity 121, thereby further improving the limit of the torque load that the gear shaft structure 100 can withstand.

[0059] Therefore, by setting the clamping plate 132, the first annular friction plate 133 and the second annular friction plate 135 can be clamped, thereby transmitting the torque between the output shaft 110 and the rotating gear 120. The clamping force between the clamping plate 132 and the rotating gear 120 is mainly provided by the compression deformation of the disc spring 134. In addition, a certain gap must be maintained between the clamping plate 132 and the rotating gear 120 to ensure that the first annular friction plate 133 and the second annular friction plate 135 can be clamped. Moreover, there is zero gap between the first annular friction plate 133 and the second annular friction plate 135 and the rotating gear 120, which mainly serves to support the radial force of the rotating gear 120.

[0060] With the connecting boss 112 in place, when installing the cylindrical friction plate 131, the cylindrical friction plate 131 can be fitted onto the connecting boss 112, and the cylindrical friction plate 131 and the connecting boss 112 are interference-fitted.

[0061] Based on the above structural settings, please refer to Figures 1-4 In this embodiment, to facilitate the assembly of the aforementioned transmission part 111, cylindrical friction plate 131, first annular friction plate 133, second annular friction plate 135, and pressure plate 132, the inner wall of the transmission cavity 121 is provided with a first annular cavity 122 and a second annular cavity 123. The first annular cavity 122 and the second annular cavity 123 are connected, and the inner diameter of the first annular cavity 122 is smaller than the inner diameter of the second annular cavity 123. A stepped surface 124 is formed at the connection between the first annular cavity 122 and the second annular cavity 123. The connecting boss 112 is housed in the first annular cavity 122, and the pressure plate 132 is housed in the second annular cavity 123. The connecting bolt is connected to the stepped surface 124, and the surface of the pressure plate 132 used to press the first annular friction plate 133 is spaced apart from the stepped surface 124.

[0062] Therefore, this arrangement facilitates the installation of the friction plate assembly 130 and improves the assembly stability of the output shaft 110 and the rotating gear 120.

[0063] In summary, the gear shaft structure 100 adopts a configuration that splits the gear shaft into two parts: a rotating gear 120 and an output shaft 110. A friction plate assembly 130 is placed between the rotating gear 120 and the output shaft 110, and a disc spring 134 is used to pre-tighten the cylindrical friction plate 131. As a result, when the load exceeds the torque value generated by the pre-tightening of the disc spring 134, relative rotational sliding occurs between the rotating gear 120 and the output shaft 110, thereby realizing the self-protection function of the gear shaft structure 100 and the yaw gearbox.

[0064] Based on the gear shaft structure 100 described above, please refer to... Figures 1-4This embodiment also provides a wind turbine generator, which includes a tower, a nacelle, a yaw bearing, a yaw motor, and a yaw gearbox;

[0065] The nacelle and the tower are rotatably connected; the inner ring of the yaw bearing is connected to the tower, and the outer ring of the yaw bearing is connected to the nacelle; the yaw gearbox is connected to the nacelle, and the yaw gearbox includes the aforementioned gear shaft structure 100, the output shaft 110 is connected to the yaw motor, and the rotating gear 120 meshes with the yaw bearing.

[0066] Based on the aforementioned gear shaft structure 100, during the yaw motion of the wind turbine, the gear shaft structure 100 transmits torque while simultaneously setting a slippage torque between the rotating gear 120 and the output shaft 110. When the rotating gear 120 is subjected to a load exceeding the limit of the yaw gearbox, slippage occurs between the rotating gear 120 and the output shaft 110, thus protecting the gear shaft structure 100 and the yaw gearbox. In addition, the gear shaft structure 100 has the advantage of simple structure and can adjust the maximum load it can bear through structural adjustments of the friction plate assembly 130, thereby improving its adaptability and reducing its structural size. In addition, since the yaw motor has a built-in rotary encoder at its tail end, the rotational speed of the yaw motor can be monitored in real time. The nacelle is equipped with a torsion cable sensor, which can monitor the rotational speed of the nacelle in real time. By comparing the rotational speeds of the yaw motor and the nacelle, it can be determined whether the wind turbine is affected by extreme loads such as turbulence, and the control strategy can be adjusted accordingly. It can also be determined whether there is a fault in the wind turbine yaw system under normal wind conditions, thereby achieving real-time dynamic protection of the wind turbine yaw system to the greatest extent possible.

[0067] Based on the above wind turbine, please refer to... Figures 1-5 This embodiment also provides a wind turbine protection and control method, implemented using the aforementioned wind turbine, including:

[0068] Collect the engine speed N1 and the yaw motor speed N2; determine whether the engine speed N1 multiplied by the transmission ratio i of the yaw gearbox is equal to the yaw motor speed N2;

[0069] The wind turbine operates normally when the speed N1 of the nacelle multiplied by the transmission ratio i of the yaw gearbox equals the speed N2 of the yaw motor.

[0070] If the engine speed N1 multiplied by the transmission ratio i of the yaw gearbox is not equal to the speed N2 of the yaw motor, determine whether the speed N2 of the yaw motor is equal to 0.

[0071] When the yaw motor speed N2 is equal to 0 and the nacelle speed N1 is not equal to 0, adjust the working state of the wind turbine blades and the operating power of the wind turbine.

[0072] If the yaw motor speed N2 is not equal to 0, then control all blades to retract, stop the yaw drive, and allow the wind turbine to enter standby mode.

[0073] Furthermore, in this embodiment, the steps of adjusting the operating state of the wind turbine blades and the operating power of the wind turbine include:

[0074] Control the blade section of the wind turbine to retract and cause the wind turbine to operate at limited power.

[0075] Based on meteorological station data, determine whether there will be a sudden change in wind conditions within a preset time period. If there is, continue to operate with limited power. If there is no sudden change in wind conditions, control the blades to deploy and the wind turbine to operate at full power.

[0076] Furthermore, in this embodiment, after the wind turbine enters standby mode, the steps of the wind turbine protection control method further include:

[0077] Determine whether the engine nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox is equal to the yaw motor speed N2;

[0078] If the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox is not equal to the yaw motor speed N2, then the wind turbine will be controlled to issue an alarm shutdown and maintenance signal.

[0079] When the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox equals the yaw motor speed N2, the wind turbine can restart the yaw system.

[0080] In summary, please refer to the following: Figures 1-5 The operation process of this wind turbine protection and control method is as follows:

[0081] It should be noted that, based on the aforementioned gear shaft structure 100 and wind turbine, the nacelle rotation speed in this embodiment is N1, and the yaw motor rotation speed is N2. Under normal circumstances, the output speed of the yaw motor is N2. The output of the yaw motor is reduced to the output shaft 110 through the yaw reduction gearbox, and then transmitted to the rotating gear 120. The rotating gear 120 meshes with the gear ring of the yaw bearing, ultimately driving the nacelle to rotate. The transmission ratio generated in this process is set as i. Therefore, the rotation speed of the nacelle is N1*i = N2. If slippage occurs between the output shaft 110 of the gear shaft structure 100 and the rotating gear 120, then N1*i ≠ N2. The wind turbine protection and control method is set based on this.

[0082] First, the nacelle speed N1 and the yaw motor speed N2 are collected; the relevant data are then uploaded to the wind turbine main control center.

[0083] The wind turbine main control center then processes the received data and determines whether the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox is equal to the yaw motor speed N2.

[0084] When the speed N1 of the nacelle multiplied by the transmission ratio i of the yaw gearbox equals the speed N2 of the yaw motor, the wind turbine operates normally; that is, at this time the wind turbine is not affected by sudden impact loads such as turbulence.

[0085] When the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox is not equal to the yaw motor speed N2, that is, when the wind turbine is not affected by sudden impact loads such as turbulence, slippage occurs between the output shaft 110 and the rotating gear 120. At this time, the wind turbine main control center needs to determine whether the yaw motor speed N2 is equal to 0.

[0086] Based on the determination of whether the yaw motor speed N2 is equal to 0, the wind turbine main control center has the following processing methods:

[0087] When the yaw motor speed N2 is equal to 0 and the nacelle speed N1 is not equal to 0, the wind turbine is generating electricity in the wind and the turbine head is blown. In order to protect the safety of the wind turbine yaw system, the blades of the wind turbine are controlled to retract and the wind turbine is made to operate at limited power.

[0088] Based on meteorological station data, the wind turbine main control center can also determine whether there is a sudden change in wind conditions within a preset time period. If there is, it will continue to operate with limited power. If there is no sudden change in wind conditions, it will control the blades to unfold and the wind turbine to operate at full power. It will also continue to determine whether the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox is equal to the yaw motor speed N2. The steps after the determination are as above. In this embodiment, the preset time period is 10 minutes.

[0089] When the speed N2 of the yaw motor is not equal to 0, it means that the wind turbine is performing yaw motion. Slippage occurs between the rotating gear 120 and the output shaft 110. The wind turbine head is dragged in the opposite direction or accelerated in the forward direction. At this time, the damage to the yaw system of the wind turbine is extremely great. Therefore, the yaw drive is stopped by retracting all the blades of the wind turbine, and the wind turbine enters standby mode.

[0090] After running in standby mode for a certain period of time, the wind turbine main control center determines whether the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox is equal to the yaw motor speed N2.

[0091] If the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox is not equal to the yaw motor speed N2, the wind turbine will be controlled to issue an alarm shutdown and maintenance signal; and then the maintenance personnel will be automatically notified to go on the machine to check the yaw system fault.

[0092] When the nacelle speed N1 multiplied by the transmission ratio i of the yaw gearbox equals the yaw motor speed N2, the wind turbine can restart the yaw system; that is, the wind turbine can restart the yaw system to allow the wind turbine to generate electricity from the wind, and the wind turbine will operate normally.

[0093] This wind turbine protection and control method, through structural improvements to the output shaft 110 and rotating gear 120 of the yaw gearbox, greatly reduces the occurrence of yaw system failures, significantly reduces damage to the mechanical components of the wind turbine, and effectively avoids damage to the wind turbine caused by sudden shocks such as turbulence.

[0094] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A protection and control method for a wind turbine generator, implemented using a wind turbine generator, characterized in that: The wind turbine includes a tower, a nacelle, a yaw bearing, a yaw motor, and a yaw gearbox. The nacelle is rotatably connected to the tower. The inner ring of the yaw bearing is connected to the tower, and the outer ring of the yaw bearing is connected to the nacelle. The yaw gearbox is connected to the nacelle and includes a gear shaft structure, which includes an output shaft, a rotating gear, and a friction plate assembly. The output shaft is equipped with a transmission part, and the rotating gear is equipped with a transmission cavity. The output shaft and the rotating gear are rotatably connected, and the transmission part is housed within the transmission cavity. The friction plate assembly includes a cylindrical friction plate, which is sleeved on the transmission part and contacts the inner peripheral wall of the transmission cavity, thereby generating friction between the outer peripheral surface of the transmission part and the inner peripheral wall of the transmission cavity to drive the transmission part and the transmission cavity. The output shaft is connected to the yaw motor, and the rotating gear meshes with the yaw bearing; The wind turbine protection and control method includes: Collect the rotational speed N1 of the engine compartment and the rotational speed N2 of the yaw motor; determine whether the rotational speed N1 of the engine compartment multiplied by the transmission ratio i of the yaw gearbox is equal to the rotational speed N2 of the yaw motor; The wind turbine operates normally when the rotational speed N1 of the nacelle multiplied by the transmission ratio i of the yaw gearbox equals the rotational speed N2 of the yaw motor. If the speed N1 of the engine compartment multiplied by the transmission ratio i of the yaw gearbox is not equal to the speed N2 of the yaw motor, determine whether the speed N2 of the yaw motor is equal to 0. When the yaw motor speed N2 is equal to 0 and the nacelle speed N1 is not equal to 0, the blades of the wind turbine are partially retracted, and the wind turbine operates at limited power. Based on meteorological station data, it is determined whether there is a sudden change in wind conditions within a preset time period. If there is, the limited power operation continues. If there is no sudden change in wind conditions, the blades are deployed and the wind turbine operates at full power. If the rotational speed N2 of the yaw motor is not equal to 0, then control all the blades to retract, stop the yaw drive, and allow the wind turbine to enter standby mode.

2. The wind turbine protection and control method according to claim 1, characterized in that: The friction plate assembly includes a pressure plate and a first annular friction plate; the pressure plate is connected to the rotating gear by a plurality of connecting bolts, the first annular friction plate is connected to the transmission part, and the pressure plate presses the first annular friction plate.

3. The wind turbine protection and control method according to claim 2, characterized in that: The friction plate assembly also includes multiple disc springs, each of which is fitted onto one of the connecting bolts and abuts against the pressure plate, so that the pressure plate has a tendency to move toward the first annular friction plate.

4. The wind turbine protection and control method according to claim 2, characterized in that: The outer peripheral surface of the transmission part is provided with a connecting boss, and along the axial direction of the output shaft, the two ends of the connecting boss are respectively provided with a first connecting surface and a second connecting surface; The friction plate assembly further includes a second annular friction plate, wherein the first annular friction plate is connected to the first connecting surface, and the second annular friction plate is connected to the second connecting surface; The second annular friction plate is in contact with the inner wall of the transmission cavity.

5. The wind turbine protection and control method according to claim 4, characterized in that: The cylindrical friction pad is fitted onto the connecting boss.

6. The wind turbine protection and control method according to claim 5, characterized in that: The inner wall of the transmission cavity is provided with a first annular cavity and a second annular cavity. The first annular cavity is connected to the second annular cavity, and the inner diameter of the first annular cavity is smaller than the inner diameter of the second annular cavity. A stepped surface is formed at the connection between the first annular cavity and the second annular cavity. The connecting boss is housed in the first annular cavity, and the clamping plate is housed in the second annular cavity; the connecting bolt is connected to the stepped surface, and the surface of the clamping plate used to hold the first annular friction piece is spaced apart from the stepped surface.

7. The wind turbine protection and control method according to claim 1, characterized in that: After the wind turbine enters the standby mode, the steps of the wind turbine protection control method further include: Determine whether the engine rotation speed N1 multiplied by the transmission ratio i of the yaw gearbox is equal to the rotation speed N2 of the yaw motor; If the nacelle rotational speed N1 multiplied by the transmission ratio i of the yaw gearbox is not equal to the yaw motor rotational speed N2, then the wind turbine generator is controlled to issue an alarm shutdown and maintenance signal. When the nacelle rotational speed N1 multiplied by the transmission ratio i of the yaw gearbox equals the rotational speed N2 of the yaw motor, the wind turbine can restart the yaw system.

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