Oil control structure, wind turbine yaw system, control method and wind turbine generator set

Abstract

This invention relates to the field of wind power generation technology, specifically to a hydraulic control structure, a wind turbine yaw system, a control method, and a wind turbine generator set. The hydraulic control structure is suitable for connection to a yaw brake hydraulic circuit. The hydraulic control structure is configured such that: when the average wind speed within a preset time is greater than a preset wind speed, the output pressure of the hydraulic control structure is maintained at a preset pressure; and / or, when the average wind speed within a preset time is less than a preset wind speed and the power of the wind turbine generator set is less than a preset power, the output pressure of the hydraulic control structure changes proportionally between zero and the preset pressure. This invention can adjust the output pressure of the hydraulic control structure according to the wind speed, ensuring yaw stability, reducing wear on the yaw brake, and extending its service life.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, specifically to an oil control structure, a wind turbine yaw system, a control method, and a wind turbine generator set. Background Technology

[0002] In the process of wind power generation, a yaw system is needed to adjust the wind turbine and align it with the wind direction so that the wind turbine can obtain the maximum wind energy and improve the efficiency of wind power generation.

[0003] A typical yaw system includes a wind vane that senses wind direction, a yaw motor, a yaw planetary gear reducer, a yaw brake (yaw damper or yaw caliper), and a large rotating gear. Its working principle is as follows: The wind vane, acting as a sensing element, transmits the change in wind direction as an electrical signal to the processor in the yaw motor's control circuit. After comparison, the processor sends a clockwise or counterclockwise yaw command to the yaw motor. To reduce the gyroscopic torque during yaw, the motor speed is reduced through a coaxially connected reducer, and the yaw torque is then applied to the large rotating gear, causing the wind turbine to yaw against the wind. Once the yaw is complete, the yaw brake acts on the large rotating gear to brake, the wind vane loses its electrical signal, the motor stops working, and the yaw process ends.

[0004] Yaw brakes currently commonly employ a yaw brake piston cylinder to pressurize the friction pads. This pressure acts on the friction disc of the rotating large gear for friction braking. The yaw brake piston cylinder is connected to the yaw brake hydraulic circuit, and the back pressure is controlled by the cooperation of one or more relief valves and zero-position valves on the yaw brake hydraulic circuit. This, in turn, adjusts the yaw brake pressure to ensure that the friction pads abut against the friction disc to achieve braking or separation, thus enabling the wind turbine to yaw against the wind.

[0005] Currently, the adjustment of yaw braking pressure is divided into full pressure and back pressure control. Back pressure is usually a specific pressure or several specific pressures to make the wind turbine have damped yaw and improve yaw stability. However, the yaw braking pressure cannot be adjusted with changes in wind speed and / or wind turbine power. Higher wind speeds usually require higher back pressure to maintain yaw stability. When the wind speed is low, excessive back pressure will lead to excessive wear and consumption of friction plates, increasing operation and maintenance costs. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the yaw braking pressure in the prior art cannot be adjusted according to the wind speed and / or the power of the wind turbine, thereby providing an oil control structure, a wind turbine yaw system, a control method and a wind turbine generator set that can adjust the yaw braking pressure according to the wind speed and / or the power of the wind turbine.

[0007] To address the aforementioned problems, the present invention provides an oil control structure suitable for connection to a yaw braking oil circuit; the oil control structure is configured such that: when the average wind speed within a preset time period is greater than a preset wind speed, the output pressure of the oil control structure is maintained at a preset pressure; and / or, when the average wind speed within the preset time period is less than the preset wind speed and the power of the wind turbine generator is less than a preset power, the output pressure of the oil control structure changes proportionally between zero and the preset pressure.

[0008] The present invention also provides a wind turbine yaw system, comprising: the above-mentioned hydraulic control structure; the yaw braking hydraulic circuit, connected to the hydraulic control structure, for adjusting the hydraulic pressure of the yaw braking hydraulic circuit through the hydraulic control structure; and a yaw brake, connected to the yaw braking hydraulic circuit, the yaw brake being adapted to cooperate with a friction disc under the drive of the yaw braking hydraulic circuit.

[0009] Optionally, the oil control structure is an electro-proportional valve.

[0010] Optionally, the yaw brake oil circuit includes an inlet oil circuit and an outlet oil circuit. The inlet oil circuit is connected to both the oil tank and the inlet of the electro-proportional valve, and the outlet oil circuit is connected to both the outlet of the electro-proportional valve and the yaw brake.

[0011] Optionally, the wind turbine yaw system further includes a controller connected to a telecommunications interface of the electro-proportional valve to control the opening of the electro-proportional valve.

[0012] Optionally, the wind turbine yaw system further includes a pressure relief oil circuit, one end of which is connected to the oil outlet circuit, and the other end of which is connected to the oil tank. A pressure relief switch valve is provided on the pressure relief oil circuit.

[0013] Optionally, an oil pump and a check valve are provided on the oil inlet line; and / or, a filter is provided on the oil inlet line and / or the oil outlet line.

[0014] The present invention also provides a control method for the wind turbine yaw system as described above, comprising the following steps: when the average wind speed within a preset time is greater than the preset wind speed, the output pressure of the control oil control structure is maintained at the preset pressure.

[0015] Optionally, the control method further includes: when the average wind speed within the preset time is less than the preset wind speed and the power of the wind turbine generator is less than the preset power, controlling the output pressure of the oil control structure to change proportionally between zero and the preset pressure according to the change in wind speed.

[0016] Optionally, the step of controlling the output pressure of the oil control structure to change proportionally between zero and the preset pressure according to the change in wind speed includes: if the wind speed decreases, controlling the output pressure of the oil control structure to decrease proportionally between zero and the preset pressure; if the wind speed increases, controlling the output pressure of the oil control structure to increase proportionally between zero and the preset pressure.

[0017] Optionally, the statement that if the wind speed decreases, the output pressure of the hydraulic control structure is controlled to decrease proportionally between zero and the preset pressure includes: if the wind speed decreases by X m / s, the output pressure of the hydraulic control structure decreases by Y bar; and / or, the statement that if the wind speed increases, the output pressure of the hydraulic control structure is controlled to increase proportionally between zero and the preset pressure includes: if the wind speed increases by X m / s, the output pressure of the hydraulic control structure increases by Y bar; wherein Y is obtained by the following formula: Y = (preset pressure ÷ preset wind speed) × X.

[0018] The present invention also provides a wind turbine generator set, including the wind turbine yaw system described above.

[0019] The present invention has the following advantages:

[0020] 1. The hydraulic control structure of the present invention can adjust the output pressure according to the wind speed, thereby regulating the oil pressure of the yaw brake circuit. When the average wind speed within a preset time is greater than the preset wind speed, the output pressure of the hydraulic control structure is maintained at the preset pressure, which can ensure smooth and damped yaw of the wind turbine generator set under excessive wind speed and improve yaw stability; and / or, when the average wind speed within a preset time is less than the preset wind speed and the power of the wind turbine generator set is less than the preset power, the output pressure of the hydraulic control structure changes proportionally between zero and the preset pressure, so that the output pressure of the hydraulic control structure can be adjusted proportionally according to the change of wind speed, ensuring smooth yaw of the wind turbine generator set under low wind speed, and also reducing the wear of the friction disc on the yaw brake, extending the service life of the yaw brake and reducing operation and maintenance costs.

[0021] 2. The wind turbine yaw system of the present invention includes the hydraulic control structure of the present invention, the yaw braking oil circuit is connected to the hydraulic control structure to adjust the oil pressure of the yaw braking oil circuit through the hydraulic control structure, the yaw brake is connected to the yaw braking oil circuit, and the yaw brake is adapted to cooperate with the friction disc under the drive of the yaw braking oil circuit. By linking wind speed with the output pressure of the hydraulic control structure, the output pressure of the hydraulic control structure can be adjusted according to the wind speed. Specifically, when the average wind speed within a preset time is greater than the preset wind speed, the output pressure of the hydraulic control structure is maintained at the preset pressure. Under the preset pressure, the wind turbine has damped yaw, that is, the yaw brake and the friction disc work together to improve yaw stability. When the average wind speed within a preset time is less than the preset wind speed and the power of the wind turbine is less than the preset power, the output pressure of the hydraulic control structure changes proportionally between zero and the preset pressure. This allows the output pressure of the hydraulic control structure to be adjusted proportionally according to the change in wind speed, ensuring that the yaw damping of the wind turbine is small when the wind speed is low, that is, the wear between the yaw brake and the friction disc is small. This ensures smooth yaw and reduces the wear of the friction disc on the yaw brake when the wind speed is low, extending the service life of the yaw brake and reducing operation and maintenance costs.

[0022] 3. The wind turbine yaw system of the present invention uses an electro-proportional valve for hydraulic control. The electro-proportional valve controls and adjusts the oil pressure in the yaw braking circuit, making adjustment convenient. Compared to the method of coordinating multiple hydraulic valves and relief valves for adjustment, the electro-proportional valve structure is more optimized and facilitates later maintenance and repair.

[0023] 4. The wind turbine yaw system of the present invention includes an inlet oil circuit and an outlet oil circuit. The inlet oil circuit is connected to both the oil tank and the inlet of the electro-proportional valve, while the outlet oil circuit is connected to both the outlet of the electro-proportional valve and the yaw brake. Oil in the oil tank enters the electro-proportional valve through the inlet oil circuit, and then flows through the outlet oil circuit to the yaw brake to drive it to engage with the friction disc, thereby achieving yaw and braking of the wind turbine generator set.

[0024] 5. The wind turbine yaw system of the present invention further includes a pressure relief oil circuit. One end of the pressure relief oil circuit is connected to the oil outlet circuit, and the other end of the pressure relief oil circuit is connected to the oil tank. A pressure relief switch valve is provided on the pressure relief oil circuit. When maintenance is required, the pressure relief switch valve is opened to allow the oil in the yaw braking oil circuit to flow through the pressure relief oil circuit and be discharged into the oil tank. Under normal operation, the pressure relief switch valve is in the closed state to allow normal oil flow in the yaw braking oil circuit.

[0025] 6. The control method of the wind turbine yaw system of the present invention includes the following steps: when the average wind speed within a preset time is greater than the preset wind speed, the output pressure of the control hydraulic structure is maintained at the preset pressure. The above control method can ensure that the wind turbine generator can yaw smoothly and with damping when the wind speed is too high. Compared with directly setting the yaw residual pressure to zero, the present invention maintains a certain preset pressure, which can improve yaw stability while achieving yaw.

[0026] 7. The control method for the wind turbine yaw system of the present invention further includes: when the average wind speed within a preset time is less than a preset wind speed and the power of the wind turbine generator set is less than a preset power, controlling the output pressure of the hydraulic control structure to change proportionally between zero and a preset pressure according to the change in wind speed. This control method enables the output pressure of the hydraulic control structure to be adjusted proportionally according to the change in wind speed, ensuring smooth yaw of the wind turbine generator set when the wind speed is low, and can proportionally adjust the output pressure of the hydraulic control structure according to the change in wind speed, thus ensuring smooth yaw and reducing the wear of the friction disc on the yaw brake when the wind speed is low, thereby extending the service life of the yaw brake.

[0027] 8. The control method of the wind turbine yaw system of the present invention controls the output pressure of the electro-proportional valve to change proportionally between zero and a preset pressure according to the change of wind speed, including: if the wind speed decreases, the output pressure of the control hydraulic structure decreases proportionally between zero and the preset pressure; if the wind speed increases, the output pressure of the control hydraulic structure increases proportionally between zero and the preset pressure. In this control method, the output pressure of the control hydraulic structure decreases proportionally between zero and the preset pressure when the wind speed decreases, that is, the lower the wind speed, the smaller the yaw damping and the smoother the yaw of the wind turbine generator set; the output pressure of the control hydraulic structure increases proportionally between zero and the preset pressure when the wind speed increases, that is, the greater the wind speed, the greater the yaw damping and the higher the yaw stability of the wind turbine generator set. Furthermore, adjusting the output pressure of the control hydraulic structure proportionally according to the change of wind speed can also effectively reduce the wear of the friction plates in the yaw brake while ensuring yaw, ensuring its service life and reducing operation and maintenance costs.

[0028] 9. The control method for the wind turbine yaw system of the present invention, wherein if the wind speed decreases, the output pressure of the control hydraulic structure decreases proportionally between zero and a preset pressure, including: if the wind speed decreases by X m / s, the output pressure of the control hydraulic structure decreases by Y bar; and / or, if the wind speed increases, the output pressure of the control hydraulic structure increases proportionally between zero and a preset pressure, including: if the wind speed increases by X m / s, the output pressure of the control hydraulic structure increases by Y bar; wherein Y is obtained by the following formula: Y = (preset pressure ÷ preset wind speed) × X. The above control method clearly defines the calculation method for the proportional increase or decrease of the output pressure of the control hydraulic structure with changes in wind speed, so as to achieve precise pressure regulation and improve the control accuracy of the entire system.

[0029] 10. The wind turbine generator set of the present invention includes a wind turbine yaw system. It can adjust the output pressure of the hydraulic control structure according to the wind speed, ensuring yaw stability, reducing wear on the yaw brake, and extending its service life. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the structure of a wind turbine yaw system according to an embodiment of the present invention is shown.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Yaw brake hydraulic circuit; 11. Inlet hydraulic circuit; 111. Hydraulic pump; 112. Check valve; 113. Filter; 12. Outlet hydraulic circuit; 2. Yaw brake; 3. Electro-proportional valve; 4. Pressure relief hydraulic circuit; 41. Pressure relief switch valve; 5. Oil tank; 6. Controller. Detailed Implementation

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] like Figure 1 As shown, this embodiment discloses an oil control structure suitable for connection with yaw brake oil circuit 1; the oil control structure is configured such that when the average wind speed within a preset time is greater than the preset wind speed, the output pressure of the oil control structure is maintained at the preset pressure; and / or, when the average wind speed within a preset time is less than the preset wind speed and the power of the wind turbine generator is less than the preset power, the output pressure of the oil control structure changes proportionally between zero and the preset pressure.

[0039] The hydraulic control structure of this embodiment can adjust the output pressure according to the wind speed, thereby regulating the oil pressure of the yaw brake oil circuit 1. When the average wind speed within a preset time is greater than the preset wind speed, the output pressure of the hydraulic control structure is maintained at the preset pressure, which can ensure smooth and damped yaw of the wind turbine generator set under excessive wind speed and improve yaw stability; and / or, when the average wind speed within a preset time is less than the preset wind speed and the power of the wind turbine generator set is less than the preset power, the output pressure of the hydraulic control structure changes proportionally between zero and the preset pressure, so that the output pressure of the hydraulic control structure can be adjusted proportionally according to the change of wind speed, ensuring smooth yaw of the wind turbine generator set under low wind speed, and also reducing the wear of the friction disc on the yaw brake, extending the service life of the yaw brake and reducing operation and maintenance costs.

[0040] This embodiment also discloses a wind turbine yaw system, including the hydraulic control structure, yaw braking oil circuit 1, and yaw brake 2 of this embodiment. The yaw brake 2 is connected to the yaw braking oil circuit 1 and is adapted to cooperate with the friction disc under the drive of the yaw braking oil circuit 1. The yaw braking oil circuit 1 is connected to the hydraulic control structure so as to adjust the oil pressure of the yaw braking oil circuit 1 through the hydraulic control structure.

[0041] The wind turbine yaw system in this embodiment establishes a connection between wind speed and the output pressure of the hydraulic control structure, so that the output pressure of the hydraulic control structure is adjusted according to the wind speed. Specifically, when the average wind speed within a preset time is greater than the preset wind speed, the output pressure of the hydraulic control structure is maintained at the preset pressure. Under the preset pressure, the wind turbine generator has damped yaw, that is, the yaw brake 2 and the friction disc are in frictional contact, which improves yaw stability. When the average wind speed within a preset time is less than the preset wind speed and the power of the wind turbine generator is less than the preset power, the output pressure of the hydraulic control structure changes proportionally between zero and the preset pressure, so that the output pressure of the hydraulic control structure can be adjusted proportionally according to the change of wind speed. This ensures that the yaw damping of the wind turbine generator is small when the wind speed is low, that is, the wear between the yaw brake 2 and the friction disc is small. This ensures smooth yaw and reduces the wear of the friction disc on the yaw brake 2 when the wind speed is low, extending the service life of the yaw brake 2 and reducing operation and maintenance costs.

[0042] Understandably, when the wind speed is high (greater than the preset wind speed), if the wind turbine yaws without damping (i.e., there is no friction between the friction disc and the yaw brake 2), the wind turbine is prone to swaying and has poor yaw stability. Therefore, maintaining the output pressure of the hydraulic control structure at the preset pressure allows the friction disc and the yaw brake 2 to slide, achieving damped yaw of the wind turbine and thus improving yaw stability. Conversely, when the wind speed is low (less than the preset wind speed), if the damping of the wind turbine is too high (i.e., the friction between the friction disc and the yaw brake 2 is too great), it will cause excessive wear on the yaw brake 2 (specifically the friction pads inside), affecting its service life. Therefore, adjusting the output pressure of the hydraulic control structure proportionally according to the wind speed change can reduce wear on the yaw brake 2 while achieving yaw of the wind turbine, extending its service life and reducing maintenance and replacement costs.

[0043] The structure of the wind turbine yaw system will be described in detail below with reference to the accompanying drawings.

[0044] In this embodiment, the hydraulic control structure is an electro-proportional valve 3. The oil pressure of the yaw brake circuit 1 is controlled and adjusted by the electro-proportional valve 3, which is convenient for adjustment. Compared with the method of adjusting by multiple hydraulic valves and relief valves, the electro-proportional valve 3 has a more optimized structure and is more convenient for later maintenance and repair.

[0045] Specifically, the electro-proportional valve 3 includes an oil inlet, an oil outlet, and a telecommunications interface. The oil inlet and outlet are connected, and the telecommunications interface facilitates the transmission or reception of electrical signals.

[0046] When the electro-proportional valve 3 is de-energized, the yaw brake oil circuit 1 drives the yaw brake 2 to engage with the friction disc according to the system oil pressure, thereby achieving yaw braking of the wind turbine generator set. At this time, the wind turbine generator set does not yaw. When the electro-proportional valve 3 is energized, the electro-proportional valve 3 reduces the oil flow rate, thereby reducing the oil pressure at the outlet of the electro-proportional valve 3, causing the yaw brake 2 to gradually separate from the friction disc (the separation distance is determined by the oil pressure). At this time, the wind turbine generator set can yaw. After the wind turbine generator set yaws to the corresponding position, the electro-proportional valve 3 switches to the de-energized state, causing the yaw brake 2 to engage with the friction disc again to achieve yaw braking.

[0047] The yaw braking hydraulic circuit 1 includes an inlet hydraulic circuit 11 and an outlet hydraulic circuit 12. The inlet hydraulic circuit 11 is connected to both the oil tank 5 and the inlet of the electro-proportional valve 3, while the outlet hydraulic circuit 12 is connected to both the outlet of the electro-proportional valve 3 and the yaw brake 2. The hydraulic fluid in the oil tank 5 enters the electro-proportional valve 3 through the inlet hydraulic circuit 11, and then flows through the outlet hydraulic circuit 12 to the yaw brake 2 to drive the yaw brake 2 to engage with the friction disc, thereby achieving yaw and braking of the wind turbine generator.

[0048] Furthermore, this embodiment includes an oil pump 111 and a check valve 112 on the oil inlet passage 11 to facilitate the power transmission and unidirectional flow of oil in the oil inlet passage 11 and the oil outlet passage 12. To prevent impurities from clogging the pipes or valve structure, a filter 113 can be installed on the oil inlet passage 11 and / or the oil outlet passage 12 to filter impurities in the oil. Specifically, the oil pump 111 can be installed inside the oil tank 5, and the filter 113 can be installed between the oil pump 111 and the check valve 112, so that the oil is filtered before flowing through the check valve 112.

[0049] In this embodiment, the yaw brake 2 is a yaw caliper, and a friction plate is installed inside the yaw caliper. The yaw caliper is driven by a piston hydraulic cylinder to make the friction plate abut against the friction disc, thereby achieving yaw braking. Since the structure and principle of the yaw brake 2 are existing technologies, they will not be described in detail in this embodiment. In other embodiments, the yaw brake 2 can also be set as a yaw damper, which can also achieve the function of yaw braking, and is not limited to the solution of this embodiment.

[0050] The wind turbine yaw system in this embodiment also includes a controller 6, which is connected to the electro-proportional valve 3 via a telecommunication interface to control the opening of the electro-proportional valve 3. The controller 6 establishes a telecommunication connection with the electro-proportional valve 3 through the telecommunication interface, enabling the controller 6 to control the opening of the electro-proportional valve 3 via electrical signals, thus achieving intelligent and precise control. Since the structure and principle of the controller 6 are existing technologies, they will not be described in detail in this embodiment.

[0051] In this embodiment, the wind turbine yaw system also includes a pressure relief oil circuit 4. One end of the pressure relief oil circuit 4 is connected to the oil outlet circuit 12, and the other end of the pressure relief oil circuit 4 is connected to the oil tank 5. A pressure relief switch valve 41 is provided on the pressure relief oil circuit 4. When maintenance is required on the electro-proportional valve 3 or the pipeline, the pressure relief switch valve 41 is opened to allow the oil in the yaw braking oil circuit 1 to flow through the pressure relief oil circuit 4 and be discharged into the oil tank 5. Under normal operation, the pressure relief switch valve 41 is in the closed state to allow normal oil flow in the yaw braking oil circuit 1.

[0052] This embodiment also discloses a control method for a wind turbine yaw system, including the following steps:

[0053] When the average wind speed within a preset time exceeds a preset wind speed, the output pressure of the control hydraulic system is maintained at a preset pressure. The above control method ensures smooth, damped yaw of the wind turbine generator under excessively high wind speeds. Compared to directly setting the yaw residual pressure to zero, maintaining a certain preset pressure in this embodiment improves yaw stability while achieving yaw.

[0054] Specifically, the oil control structure is an electro-proportional valve 3, which facilitates control and maintenance and optimizes the structure.

[0055] The control method in this embodiment further includes: when the average wind speed within a preset time is less than a preset wind speed and the power of the wind turbine generator is less than a preset power, controlling the output pressure of the hydraulic control structure to change proportionally between zero and a preset pressure according to the change in wind speed. This control method enables the output pressure of the hydraulic control structure to be adjusted proportionally according to the change in wind speed, ensuring smooth yaw of the wind turbine generator when the wind speed is low, and adjusting the output pressure of the hydraulic control structure proportionally according to the change in wind speed, thus ensuring smooth yaw and reducing wear on the yaw brake 2 by the friction disc when the wind speed is low, thereby extending the service life of the yaw brake 2.

[0056] To further understand the control method of this embodiment, a preset time of 10 seconds, a preset wind speed of 7 m / s, a preset pressure of 15 bar, and a preset power of 50% of the rated power can be set. That is, when the average wind speed within 10 seconds is greater than 7 m / s, the output pressure of the hydraulic control structure is maintained at 15 bar; when the average wind speed within 10 seconds is less than 7 m / s and the unit power is less than 50% of the rated power, the output pressure of the hydraulic control structure is proportionally varied between 0 bar and 15 bar according to the wind speed change, thereby improving the service life of the friction plates.

[0057] Of course, in other embodiments, the preset time, preset pressure, preset wind speed, and preset power can be set according to different usage scenarios and purposes, and are not limited to the above settings.

[0058] Furthermore, the output pressure of the hydraulic control structure is proportionally varied between zero and a preset pressure according to changes in wind speed. This includes: if the wind speed decreases, the output pressure of the hydraulic control structure decreases proportionally between zero and the preset pressure; if the wind speed increases, the output pressure of the hydraulic control structure increases proportionally between zero and the preset pressure. In this control method, a decrease in wind speed results in a proportional decrease in the output pressure of the hydraulic control structure, meaning that the lower the wind speed, the smaller the yaw damping, the smoother the yaw of the wind turbine generator, and the less wear on the yaw brake 2. Conversely, an increase in wind speed results in a proportional increase in the output pressure of the hydraulic control structure, meaning that the greater the wind speed, the greater the yaw damping, and the higher the yaw stability of the wind turbine generator. Therefore, by proportionally adjusting the output pressure of the hydraulic control structure according to changes in wind speed, wear on the friction plates inside the yaw brake 2 can be effectively reduced while ensuring yaw stability and extending its service life.

[0059] Specifically, if the wind speed decreases, the output pressure of the hydraulic control structure decreases proportionally between zero and the preset pressure, including: if the wind speed decreases by X m / s, the output pressure of the hydraulic control structure decreases by Y bar; and / or, if the wind speed increases, the output pressure of the hydraulic control structure increases proportionally between zero and the preset pressure, including: if the wind speed increases by X m / s, the output pressure of the hydraulic control structure increases by Y bar; where Y is obtained by the following formula: Y = (preset pressure ÷ preset wind speed) × X. The above control method clearly defines the calculation method for the proportional increase or decrease of the output pressure of the hydraulic control structure with changes in wind speed, so as to achieve precise pressure regulation and improve the control accuracy of the entire system.

[0060] For example, if the wind speed decreases by 1 m / s (i.e., X = 1), the output pressure of the hydraulic control structure decreases by 2.5 bar (Y = (15 ÷ 7) × 1); if the wind speed decreases by 2 m / s (i.e., X = 2), the output pressure of the hydraulic control structure decreases by 5 bar (Y = (15 ÷ 7) × 2).

[0061] Conversely, the pressure increases proportionally. For example, if the wind speed increases by 1 m / s (i.e., X = 1), the output pressure of the hydraulic control structure increases by 2.5 bar (Y = (15 ÷ 7) × 1); if the wind speed increases by 2 m / s (i.e., X = 2), the output pressure of the hydraulic control structure increases by 5 bar (Y = (15 ÷ 7) × 2).

[0062] This embodiment also discloses a wind turbine generator set, including the wind turbine yaw system described above, which can adjust the output pressure of the hydraulic control structure according to the wind speed to ensure yaw stability, reduce wear on the yaw brake 2, and extend its service life.

[0063] Therefore, the wind turbine yaw system, control method, and wind turbine generator set of the present invention have the following advantages: they can ensure smooth and damped yaw of the wind turbine generator set and improve yaw stability when the wind speed is too high; they can also control the output pressure of the hydraulic control structure to change proportionally between zero and a preset pressure according to the wind speed change when the wind speed is low, so as to ensure that the wind turbine generator set can yaw smoothly when the wind speed is low, while reducing the wear on the yaw brake 2, extending the service life of the yaw brake 2, and reducing the operation and maintenance costs.

[0064] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A wind turbine yaw system, characterized in that, include: The hydraulic control structure is suitable for connection with the yaw brake hydraulic circuit (1); The hydraulic control structure is configured such that when the average wind speed within a preset time is greater than the preset wind speed, the output pressure of the hydraulic control structure is maintained at the preset pressure; and / or, when the average wind speed within the preset time is less than the preset wind speed and the power of the wind turbine generator is less than the preset power, the output pressure of the hydraulic control structure is controlled to change proportionally between zero and the preset pressure according to the change in wind speed. The method of controlling the output pressure of the oil control structure to change proportionally between zero and the preset pressure based on changes in wind speed includes: If the wind speed decreases, the output pressure of the oil control structure will decrease proportionally between zero and the preset pressure. If the wind speed increases, the output pressure of the oil control structure will increase proportionally between zero and the preset pressure. The statement that if the wind speed decreases, the output pressure of the oil control structure will decrease proportionally between zero and the preset pressure includes: if the wind speed decreases by X m / s, the output pressure of the oil control structure will decrease by Y bar. And / or, the statement that if the wind speed increases, the output pressure of the oil control structure increases proportionally between zero and the preset pressure includes: if the wind speed increases by X m / s, the output pressure of the oil control structure increases by Y bar; Wherein, Y is obtained through the following formula: Y = (preset pressure ÷ preset wind speed) × X; The yaw brake oil circuit (1) is connected to the oil control structure so as to adjust the oil pressure of the yaw brake oil circuit (1) through the oil control structure; Yaw brake (2) is connected to the yaw brake oil circuit (1), and the yaw brake (2) is adapted to cooperate with the friction disc under the drive of the yaw brake oil circuit (1).

2. The wind turbine yaw system according to claim 1, characterized in that, The oil control structure is an electro-proportional valve (3).

3. The wind turbine yaw system according to claim 2, characterized in that, The yaw brake oil circuit (1) includes an inlet oil circuit (11) and an outlet oil circuit (12). The inlet oil circuit (11) is connected to the oil tank (5) and the inlet of the electro-proportional valve (3). The outlet oil circuit (12) is connected to the outlet of the electro-proportional valve (3) and the yaw brake (2).

4. The wind turbine yaw system according to claim 3, characterized in that, It also includes a controller (6) which is connected to the telecommunications interface of the electro-proportional valve (3) to control the opening of the electro-proportional valve (3).

5. The wind turbine yaw system according to claim 3, characterized in that, It also includes a pressure relief oil circuit (4), one end of which is connected to the oil outlet circuit (12), and the other end of which is connected to the oil tank (5). A pressure relief switch valve (41) is provided on the pressure relief oil circuit (4).

6. The wind turbine yaw system according to claim 3, characterized in that, The oil inlet circuit (11) is equipped with an oil pump (111) and a check valve (112); and / or, the oil inlet circuit (11) and / or the oil outlet circuit (12) are equipped with a filter (113).

7. A control method for a wind turbine yaw system, characterized in that, Includes the following steps: When the average wind speed within a preset time is greater than the preset wind speed, the output pressure of the control hydraulic system is maintained at the preset pressure; wherein, the yaw brake oil circuit (1) is connected to the hydraulic control structure so as to adjust the oil pressure of the yaw brake oil circuit (1) through the hydraulic control structure. It also includes: when the average wind speed within the preset time is less than the preset wind speed and the power of the wind turbine generator is less than the preset power, controlling the output pressure of the hydraulic control structure to change proportionally between zero and the preset pressure according to the change in wind speed; The method of controlling the output pressure of the oil control structure to change proportionally between zero and the preset pressure based on changes in wind speed includes: If the wind speed decreases, the output pressure of the oil control structure will decrease proportionally between zero and the preset pressure. If the wind speed increases, the output pressure of the oil control structure will increase proportionally between zero and the preset pressure. The statement that if the wind speed decreases, the output pressure of the oil control structure will decrease proportionally between zero and the preset pressure includes: if the wind speed decreases by X m / s, the output pressure of the oil control structure will decrease by Y bar. And / or, the statement that if the wind speed increases, the output pressure of the oil control structure increases proportionally between zero and the preset pressure includes: if the wind speed increases by X m / s, the output pressure of the oil control structure increases by Y bar; Y is obtained through the following formula: Y = (preset pressure ÷ preset wind speed) × X.

8. A wind turbine generator set, characterized in that, Includes the wind turbine yaw system as described in any one of claims 1 to 6.

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