Pitch changing mechanism of horizontal axis wind turbine and regulation and control method

Abstract

The invention belongs to the technical field of unmanned ship variable-pitch structures, and particularly relates to a horizontal axis wind turbine variable-pitch mechanism and a regulation and control method.The horizontal axis wind turbine variable-pitch mechanism comprises blades, a propeller hub, a variable-pitch unit, a transmission unit and a control unit.The blade roots of the blades penetrate through the side wall of the propeller hub and are rotationally connected with the propeller hub, and blade root gears are arranged at the ends of the blade roots; the blade root gear is connected with the variable pitch unit, the rear end of the propeller hub is connected with a brake mechanism through a transmission unit, and the control unit is electrically connected with a power supply and is configured to control the brake mechanism and the variable pitch unit. According to the invention, the fan can automatically adjust the angle and the rotating speed of the blades according to the change of the wind speed and the sailing angle, so that the utilization efficiency of wind energy is improved, the hydrodynamic load is reduced, and the stability and the control performance of the unmanned ship are improved. Meanwhile, the fan galloping phenomenon caused by too high sea surface wind speed is considered, a blade protection mechanism is designed, and protection measures are provided for safe operation of the fan.

Description

Technical Field

[0001] The present invention belongs to the technical field of variable pitch structures of unmanned ships, and in particular relates to a variable pitch mechanism and a control method for a horizontal-axis wind turbine. Background Art

[0002] Wind-powered unmanned boats represent an innovative application of renewable energy, using wind power as a power source to achieve clean and efficient energy conversion. This technology meets environmental protection needs and does not produce harmful gas emissions, thereby reducing carbon emissions. In addition, wind-powered unmanned boats can be autonomously driven and controlled to adapt to different wind conditions and mission requirements. However, existing horizontal axis wind turbines have some problems in wind-powered unmanned boats, such as low efficiency due to fixed blades and difficulty in achieving real-time blade angle adjustment.

[0003] Research on the variable pitch mechanism of horizontal axis wind turbines is of great significance to improving the efficiency of wind energy utilization. This variable pitch mechanism will provide significant advantages for the performance of wind-powered unmanned ships. By adjusting the angle of the blades in real time, it can capture wind energy to the greatest extent and improve energy conversion efficiency. Moreover, it is adaptive and can flexibly adjust the blades according to wind speed and direction, allowing wind-powered unmanned ships to better adapt to different environmental conditions.

[0004] In addition, at sea, strong winds occur frequently, and the wind turbine blades need to withstand huge wind loads, which puts higher requirements on the quality of the blades and the stability of the unmanned ship.

[0005] In summary, the horizontal axis wind turbine pitch and protection mechanism has a huge potential impact on the application of wind unmanned vessels. It can effectively improve performance, environmental protection and efficiency, and has a high research and development value. Summary of the invention

[0006] The present invention discloses a variable pitch mechanism and control method for a horizontal-axis wind turbine, which is designed for the operating environment of unmanned ships at sea, meets the requirements of stability of unmanned ships, efficient wind utilization, and blade protection in strong winds, and helps unmanned ships achieve autonomous and long-range unmanned operations in deep seas. The deflection of the angle of attack of the horizontal wind turbine blades is achieved through a lightweight and reliable variable pitch mechanism, so that the wind turbine can automatically adjust the angle and speed of the blades according to changes in wind speed and navigation angle, thereby improving the utilization efficiency of wind energy. In addition, the designed variable pitch mechanism takes into account the wind thrust of the wind turbine during adjustment, and can also reduce the hydrodynamic load and improve the stability and control performance of the unmanned boat. At the same time, considering the phenomenon of wind turbine runaway caused by excessive wind speed on the sea surface, a blade protection mechanism is designed to provide protection measures for the safe operation of the wind turbine.

[0007] To achieve the above purpose, the technical solution of the present invention is:

[0008] A horizontal axis wind turbine pitch mechanism comprises a blade, a hub, a pitch unit, a transmission unit and a control unit. The blade root of the blade passes through the side wall of the hub and is rotatably connected to the hub. A blade root gear is provided at the end of the blade root. The blade root gear is connected to the pitch unit. The rear end of the hub is connected to a brake mechanism through the transmission unit. The control unit is electrically connected to a power supply and is configured to control the brake mechanism and the pitch unit.

[0009] Preferably, the front end of the blade hub is connected to a fairing, the rear end of the blade hub is connected to a transmission unit, a plurality of through holes are evenly distributed around the axis on the outer wall of the blade hub, and the blade root passes through the through hole and is rotatably connected to the through hole via a bearing.

[0010] Preferably, there are three through holes, the three blade root gears are first bevel gear structures, the variable pitch unit includes a linkage gear arranged on the inner sides of the three first bevel gear structures, the outer periphery of the linkage gear is a second bevel gear structure, the second bevel gear structure is respectively meshed and connected with the three first bevel gear structures, and the linkage gear is driven by a driving unit.

[0011] Preferably, the linkage gear is annular and the end away from the fairing is a closed end, the inner ring of the linkage gear is provided with an internal tooth structure, the drive unit comprises a servo motor, a worm, a worm wheel, a control circuit, a lithium battery, and a Bluetooth communication receiving module arranged on the inner side of the linkage gear, the lithium battery is electrically connected to the control circuit through a wire, the Bluetooth communication receiving module is connected to the control circuit signal through a wire, the control circuit is configured to control the servo motor, the output shaft of the servo motor is fixedly connected with a worm, the worm is meshingly connected to the worm wheel, the worm wheel is meshingly connected to the internal tooth structure, and the servo motor, the control circuit, the lithium battery, and the Bluetooth communication receiving module are respectively fixed to the inner side of the closed end or the inner side of the blade hub.

[0012] Preferably, the transmission unit comprises a transmission shaft and a gear box, the front end of the transmission shaft is fixedly connected to the middle of the rear surface of the closed end, the rear end of the transmission shaft is connected to the gear box, and the gear box is connected to the brake mechanism.

[0013] Preferably, the rear end of the blade hub is fixedly connected to the outer wall of the transmission shaft, and the rear end of the transmission shaft is provided with a third bevel gear structure, and the third bevel gear structure is located in the gear box and meshingly connected with the fourth bevel gear structure, and the fixed shaft of the fourth bevel gear structure penetrates the gear box downward in the longitudinal direction, and the brake mechanism includes a brake connected to the bottom end of the fixed shaft, and the transmission shaft is rotatably connected to the gear box.

[0014] Preferably, it also includes a casing, which is sleeved outside the gear box, the front end of the casing is rotatably connected to the transmission shaft, and the rear end of the casing is connected to the windward plate via a connecting shaft coaxial with the transmission shaft.

[0015] Preferably, the control unit includes a main control board on the unmanned boat, a Bluetooth communication sending module, a wind force sensor, and a speed sensor. The speed sensor is used to detect the speed of the transmission shaft. The wind force sensor and wind speed sensor are respectively connected to the main control board signal through wires, and the main control board is connected to the Bluetooth communication receiving module signal through the Bluetooth communication sending module.

[0016] A control method for a horizontal axis wind turbine pitch mechanism, comprising: a mechanical transmission characteristic algorithm, a wind turbine aerodynamic characteristic database, a transmission system and generator characteristic database, a wind turbine-generator matching analysis algorithm and an aerodynamic performance analysis algorithm;

[0017] The mechanical transmission characteristic algorithm is used to analyze the transmission characteristics of the servo motor rotation angle and the blade pitch angle. Specifically:

[0018] Assume that the number of servo motor worm heads is K, the worm wheel is a spur gear with a tooth number of Z1, the internal tooth structure of the linkage gear is a spur gear with a tooth number of Z2, the external gear is the second bevel gear with a tooth number of Z3, and the blade root gear is the first bevel gear with a tooth number of Z4. Then their transmission ratio relationship is:

[0019] Worm and worm gear ratio

[0020] Worm gear, linkage gear ratio

[0021] Transmission ratio of linkage gear and blade root gear

[0022] Therefore, the relationship between the number of revolutions r of the servo motor and the blade pitch angle θ is:

[0023]

[0024] The wind turbine aerodynamic characteristics database is constructed based on BEM to construct the aerodynamic characteristics of the wind turbine blade configuration. The database includes wind speed V w , speed n, pitch angle The fan thrust T corresponding to the variable w , torque Q w , power P w characteristic;

[0025] The transmission system and generator characteristic database is constructed based on test data, including the torque Q corresponding to the speed n e , Generator voltage U e , Generating current Ie , power generation P e , efficiency η;

[0026] The fan-generator matching analysis algorithm reads the fan aerodynamic characteristics database, the transmission system and the generator characteristics database, selects the speed and torque matching data of the two databases under a certain wind speed, and forms the wind speed V w , pitch angle Speed ​​n, torque Q w , torque Q e , fan thrust T w , power generation P e The matching database;

[0027] The aerodynamic performance analysis algorithm reads the matching database and, based on a filtering method, filters abnormal data in which the wind turbine thrust T exceeds the hull stability limit and the torque Q is less than 0, screens and determines the torque corresponding to different pitch angles at 0 speed and a certain wind speed, and determines the optimal pitch angle through a sorting method.

[0028] The beneficial effects of the variable pitch mechanism and control method of a horizontal axis wind turbine of the present invention are as follows:

[0029] 1. The variable pitch unit of the present invention enables the wind turbine to automatically adjust the angle and rotation speed of the blades according to the changes in wind speed and sailing angle, thereby increasing the wind energy utilization rate by more than 5%, and is suitable for unstable wind conditions at sea.

[0030] 2. The variable pitch unit of the present invention has a simple structure, good stability, is easy to maintain, and is light in weight. It is suitable for use in small wind turbine-driven unmanned ships with small displacement, limited space, and long voyage time.

[0031] 3. The present invention has a simple structure, low cost, good stability, and can be adapted to mass production.

[0032] 4. The variable pitch unit of the present invention can be adjusted by taking into account the wind thrust of the wind turbine, thereby reducing the overturning moment during navigation and improving the stability and control performance of the unmanned boat.

[0033] 5. Considering the phenomenon of wind turbine runaway caused by excessive wind speed on the sea surface, the variable pitch unit is designed to adjust the blade pitch angle to 0° and lock the drive shaft with a brake mechanism to protect the blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a front view structural schematic diagram of the present invention.

[0035] Figure 2 It is a schematic diagram of the local structure of the present invention.

[0036] Figure 3 It is a schematic diagram of the control unit components of the present invention.

[0037] Figure 4 It is a rear view structural schematic diagram of the present invention.

[0038] Figure 5 It is a side structural schematic diagram of the present invention.

[0039] The figure shows: 1. Bluetooth communication receiving module, 2. control circuit, 3. servo motor, 4. worm, 5. worm wheel, 6. blade root gear, 7. linkage gear, 71. second bevel gear structure, 72. closed end, 73. internal gear structure, 8. wind sensor, 9. speed sensor, 10. main control board, 11. Bluetooth communication sending module, 12. bearing, 13. blade, 131. blade root, 14. gear box, 15. windward plate, 16. brake, 17. blade hub, 18. fairing, 19. casing, 20. transmission shaft, 21. fourth bevel gear structure, 22. third bevel gear structure. DETAILED DESCRIPTION

[0040] The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0041] The following embodiments may be understood as individually expressing a part of a local structure or method of the present invention, or may be understood as a combination of the embodiments to explain the connotation of a larger structure or method of the present invention.

[0042] Example 1

[0043] A horizontal axis wind turbine pitch mechanism, such as Figure 1-5 As shown, it includes a blade 13, a hub 17, a pitch unit, a transmission unit, and a control unit. The blade root 131 of the blade 13 passes through the side wall of the hub 17 and is rotatably connected to the hub 17. A blade root gear 6 is provided at the end of the blade root 131. The blade root gear 6 is connected to the pitch unit. The rear end of the hub 17 is connected to a brake mechanism through a transmission unit. The control unit is electrically connected to a power supply and is configured to control the brake mechanism and the pitch unit.

[0044] Example 2

[0045] like Figure 1-5 As shown, the front end of the blade hub 17 is connected to a fairing 18, the rear end of the blade hub 17 is connected to a transmission unit, a plurality of through holes are evenly distributed around the axis on the outer wall of the blade hub 17, and the blade root 131 passes through the through hole and is rotatably connected to the through hole through a bearing 12.

[0046] Example 3

[0047] like Figure 1-5As shown, there are three through holes, and the three blade root gears 6 are first bevel gear structures. The pitch unit includes a linkage gear 7 arranged on the inner sides of the three first bevel gear structures. The outer periphery of the linkage gear 7 is a second bevel gear structure 71. The second bevel gear structure 71 is respectively meshed and connected with the three first bevel gear structures. The linkage gear 7 is driven by a driving unit.

[0048] Example 4

[0049] like Figure 2 As shown, the linkage gear 7 is annular and the end away from the fairing 18 is a closed end 72, the inner ring of the linkage gear 7 is provided with an internal tooth structure 73, the drive unit includes a servo motor 3, a worm 4, a worm wheel 5, a control circuit 2, a lithium battery, and a Bluetooth communication receiving module 1 arranged on the inner side of the linkage gear 7, the lithium battery is electrically connected to the control circuit 2 through a wire, the Bluetooth communication receiving module 1 is signal-connected to the control circuit 2 through a wire, the control circuit 2 is configured to control the servo motor 3, the output shaft of the servo motor 3 is fixedly connected with the worm 4, the worm 4 is meshingly connected with the worm wheel 5, the worm wheel 5 is meshingly connected with the internal tooth structure 73, the servo motor 3, the control circuit 2, the lithium battery, and the Bluetooth communication receiving module 1 are respectively fixed to the inner side of the closed end 72 or the inner side of the blade hub.

[0050] Example 5

[0051] like Figure 1-5 As shown, the transmission unit includes a transmission shaft 20 and a gear box 14. The front end of the transmission shaft 20 is fixedly connected to the middle of the rear surface of the closed end 72, and the rear end of the transmission shaft 20 is connected to the gear box 14, which is connected to the brake mechanism.

[0052] Example 6

[0053] like Figure 1-5 As shown, the rear end of the blade hub 17 is fixedly connected to the outer wall of the transmission shaft 20, and the rear end of the transmission shaft 20 is provided with a third bevel gear structure 22. The third bevel gear structure 22 is located in the gear box 14 and is meshed with a fourth bevel gear structure 21. The fixed axis of the fourth bevel gear structure 21 penetrates the gear box 14 downward in the longitudinal direction. The brake mechanism includes a brake 16 connected to the bottom end of the fixed axis, and the transmission shaft is rotatably connected to the gear box 14.

[0054] In this embodiment, the specific structure of the brake is prior art and will not be described in detail here. The principle is to lock the fixed shaft and then lock the transmission shaft 20 through transmission.

[0055] Example 7

[0056] like Figure 1-5As shown, it also includes a casing 19, which is sleeved outside the gear box 14, the front end of the casing 19 is rotatably connected to the transmission shaft 20, and the rear end of the casing 19 is connected to the windward plate 15 through a connecting shaft coaxial with the transmission shaft 20.

[0057] Example 8

[0058] like Figure 1-5 As shown, the control unit includes a main control board 10, a Bluetooth communication sending module 11, a wind sensor 8, and a speed sensor 9 on an unmanned ship. The speed sensor 9 is used to detect the speed of the transmission shaft 20. The wind sensor 8 and the wind speed sensor 9 are respectively connected to the main control board 10 by wires, and the main control board 10 is connected to the Bluetooth communication receiving module 1 by Bluetooth communication sending module 11.

[0059] In the above embodiments, the blades obtain the wind energy provided by the environmental wind field, convert it into rotational energy, and transmit the rotational kinetic energy to the rear unit through the hub and the transmission unit. The blade root is connected to the hub through a bearing, and the radial bearing plays a role in fixing the shaking of the blade root and not restricting its rotation. The rear end of the hub is connected to the transmission shaft, which plays a role in fixing the position of the blade and transmitting the rotational force. The front end of the hub is connected to the fairing, and the servo motor, Bluetooth communication receiving module, control circuit, lithium battery, worm gear, and worm of the variable pitch unit are installed between the hub and the fairing. The casing plays the role of watertightness, diversion and support, protects the internal equipment, and smoothes the external flow field. The front end is connected to the transmission shaft, and the rear end is connected to the windward plate. There are components such as the transmission unit and the gearbox inside. The windward plate at the tail of the fan provides the fan with a windward torque. Once there is an angle between the fuselage and the wind direction, the fan will be deflected to the incoming wind direction so that it is facing the wind.

[0060] Example 9

[0061] Based on the above embodiments, this embodiment discloses a method for controlling a pitch mechanism of a horizontal axis wind turbine, such as Figure 1-5 As shown, it includes: mechanical transmission characteristic algorithm, fan aerodynamic characteristic database, transmission system and generator characteristic database, fan-generator matching analysis algorithm and aerodynamic performance analysis algorithm;

[0062] The mechanical transmission characteristic algorithm is used to analyze the transmission characteristics of the servo motor rotation angle and the blade pitch angle. Specifically:

[0063] Assume that the number of servo motor worm heads is K, the worm wheel is a spur gear with a tooth number of Z1, the internal tooth structure of the linkage gear is a spur gear with a tooth number of Z2, the external gear is the second bevel gear with a tooth number of Z3, and the blade root gear is the first bevel gear with a tooth number of Z4. Then their transmission ratio relationship is:

[0064] Worm and worm gear ratio

[0065] Worm gear, linkage gear ratio

[0066] Transmission ratio of linkage gear and blade root gear

[0067] Therefore, the relationship between the number of revolutions r of the servo motor and the blade pitch angle θ is:

[0068]

[0069] The wind turbine aerodynamic characteristics database is constructed based on BEM to construct the aerodynamic characteristics of the wind turbine blade configuration. The database includes wind speed V w , speed n, pitch angle The fan thrust T corresponding to the variable w , torque Q w , power P w characteristic;

[0070] The transmission system and generator characteristic database is constructed based on test data, including the torque Q corresponding to the speed n e , Generator voltage U e , Generating current I e , power generation P e , efficiency η;

[0071] The fan-generator matching analysis algorithm reads the fan aerodynamic characteristics database, the transmission system and the generator characteristics database, selects the speed and torque matching data of the two databases under a certain wind speed, and forms the wind speed V w , pitch angle Speed ​​n, torque Q w , torque Q e , fan thrust T w , power generation P e The matching database;

[0072] The aerodynamic performance analysis algorithm reads the matching database and, based on a filtering method, filters abnormal data in which the wind turbine thrust T exceeds the hull stability limit and the torque Q is less than 0, screens and determines the torque corresponding to different pitch angles at 0 speed and a certain wind speed, and determines the optimal pitch angle through a sorting method.

Claims

1. A horizontal axis wind turbine pitch mechanism, characterized by: It includes a blade, a hub, a pitch unit, a transmission unit, and a control unit. The root of the blade passes through the side wall of the hub and is rotatably connected to the hub. A blade root gear is provided at the end of the blade root, and the blade root gear is connected to the pitch unit. The rear end of the hub is connected to a brake mechanism through a transmission unit. The control unit is electrically connected to a power supply and is configured to control the brake mechanism and the pitch unit.

2. A horizontal axis wind turbine pitch mechanism according to claim 1, characterized in that: The front end of the blade hub is connected with a fairing, the rear end of the blade hub is connected with a transmission unit, a plurality of through holes are evenly distributed around the axis on the outer wall of the blade hub, and the blade root passes through the through hole and is rotatably connected with the through hole through a bearing.

3. A horizontal axis wind turbine pitch mechanism according to claim 2, characterized in that: There are three through holes, and the three blade root gears are first bevel gear structures. The variable pitch unit includes a linkage gear arranged on the inner side of the three first bevel gear structures. The outer periphery of the linkage gear is a second bevel gear structure. The second bevel gear structure is respectively meshed and connected with the three first bevel gear structures, and the linkage gear is driven by a driving unit.

4. A horizontal axis wind turbine pitch mechanism as claimed in claim 3, characterized in that: The linkage gear is annular and the end away from the fairing is a closed end. The inner ring of the linkage gear is provided with an internal tooth structure. The drive unit includes a servo motor, a worm, a worm wheel, a control circuit, a lithium battery, and a Bluetooth communication receiving module arranged on the inner side of the linkage gear. The lithium battery is electrically connected to the control circuit through a wire, and the Bluetooth communication receiving module is connected to the control circuit signal through a wire. The control circuit is configured to control the servo motor. The output shaft of the servo motor is fixedly connected with a worm, and the worm is meshingly connected to the worm wheel, and the worm wheel is meshingly connected to the internal tooth structure. The servo motor, the control circuit, the lithium battery, and the Bluetooth communication receiving module are respectively fixed to the inner side of the closed end or the inner side of the blade hub.

5. A horizontal axis wind turbine pitch mechanism as claimed in claim 4, characterized in that: The transmission unit comprises a transmission shaft and a gear box. The front end of the transmission shaft is fixedly connected to the middle of the rear surface of the closed end, the rear end of the transmission shaft is connected to the gear box, and the gear box is connected to the brake mechanism.

6. A horizontal axis wind turbine pitch mechanism as claimed in claim 5, characterized in that: The rear end of the blade hub is fixedly connected to the outer wall of the transmission shaft, and the rear end of the transmission shaft is provided with a third bevel gear structure. The third bevel gear structure is located in the gear box and is meshed with a fourth bevel gear structure. The fixed shaft of the fourth bevel gear structure penetrates the gear box downward in the longitudinal direction. The brake mechanism includes a brake connected to the bottom end of the fixed shaft, and the transmission shaft is rotatably connected to the gear box.

7. A horizontal axis wind turbine pitch mechanism according to claim 6, characterized in that: It also includes a casing, which is sleeved outside the gear box, the front end of the casing is rotatably connected to the transmission shaft, and the rear end of the casing is connected to a windward plate through a connecting shaft coaxial with the transmission shaft.

8. A horizontal axis wind turbine pitch mechanism according to claim 7, characterized in that: The control unit includes a main control board on the unmanned ship, a Bluetooth communication sending module, a wind force sensor, and a speed sensor. The speed sensor is used to detect the speed of the transmission shaft. The wind force sensor and wind speed sensor are respectively connected to the main control board signal through wires, and the main control board is connected to the Bluetooth communication receiving module signal through the Bluetooth communication sending module.

9. A method for controlling a pitch mechanism of a horizontal axis wind turbine according to claim 8, characterized by comprising: Mechanical transmission characteristic algorithm, fan aerodynamic characteristic database, transmission system and generator characteristic database, fan-generator matching analysis algorithm and aerodynamic performance analysis algorithm; The mechanical transmission characteristic algorithm is used to analyze the transmission characteristics of the servo motor rotation angle and the blade pitch angle. Specifically: Assume that the number of servo motor worm heads is K, the worm wheel is a spur gear with a tooth number of Z1, the internal tooth structure of the linkage gear is a spur gear with a tooth number of Z2, the external gear is the second bevel gear with a tooth number of Z3, and the blade root gear is the first bevel gear with a tooth number of Z4. Then their transmission ratio relationship is: Therefore, the relationship between the number of revolutions r of the servo motor and the blade pitch angle θ is: The wind turbine aerodynamic characteristics database is constructed based on BEM to construct the aerodynamic characteristics of the wind turbine blade configuration. The database includes wind speed V w , speed n, pitch angle The fan thrust T corresponding to the variable w , torque Q w , Power P w characteristic; The transmission system and generator characteristic database is constructed based on test data, including the torque Q corresponding to the speed n e , Generator voltage U e , Generating current I e , power generation P e , efficiency η; The fan-generator matching analysis algorithm reads the fan aerodynamic characteristics database, the transmission system and the generator characteristics database, selects the speed and torque matching data of the two databases under a certain wind speed, and forms the wind speed V w , pitch angle Speed ​​n, torque Q w , torque Q e , fan thrust T w , power generation P e The matching database; The aerodynamic performance analysis algorithm reads the matching database and, based on a filtering method, filters abnormal data in which the wind turbine thrust T exceeds the hull stability limit and the torque Q is less than 0, screens and determines the torque corresponding to different pitch angles at 0 speed and a certain wind speed, and determines the optimal pitch angle through a sorting method.

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