Miniature vertical axis wind turbine with independent variable-pitch blades

Abstract

The miniature vertical axis wind turbine comprises a supporting tower and a vertical axis wind wheel, and the bottom of the vertical axis wind wheel is connected with a transmission collecting assembly; the vertical axis wind wheel comprises a collection rotating shaft and two hubs, at least three upper supporting arms are fixed to one hub, lower supporting arms matched with the upper supporting arms in number are fixed to the other hub, and straight blades are rotationally arranged between the upper supporting arms and the lower supporting arms correspondingly; blade mounting holes for mounting straight blades are formed in the upper supporting arm and the lower supporting arm, and the bottoms of blade rotating shafts are connected with independent variable pitch mechanisms. Each blade is provided with an independent supporting, driving and monitoring system, accurate and independent regulation and control of the pitch angle of each blade of the miniature vertical axis wind turbine are achieved, and therefore the starting performance, the operation efficiency and the overall stability of the wind turbine are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and in particular to a micro vertical axis wind turbine with independently variable blade pitch. Background Technology

[0002] Vertical axis wind turbines have advantages such as simple structure, convenient maintenance, and low noise, and they have low requirements for wind fields and a wide range of applications. However, this type of turbine has long faced technical challenges such as insufficient self-starting capability and low operating efficiency, which has restricted its industrialization process.

[0003] Variable pitch technology is an effective way to solve the above problems. By adjusting the blade pitch angle, the effective angle of attack of the blade can be controlled, improving flow separation and vortex shedding characteristics, thereby optimizing the aerodynamic efficiency and load distribution of the wind turbine. However, there is limited research on independent pitch mechanisms for existing vertical axis wind turbines, and their implementation is difficult, hindering the development of this technology. Therefore, this application proposes a micro vertical axis wind turbine blade independent pitch mechanism, providing a new solution for advancing vertical axis wind turbine pitch technology. Summary of the Invention

[0004] This invention discloses a micro vertical axis wind turbine with independent blade pitch control, which solves the shortcomings of existing fixed-pitch vertical axis wind turbines and traditional centralized pitch control systems, and improves the aerodynamic performance and operational stability of the wind turbine.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A micro vertical axis wind turbine with independent blade pitch control is provided, including a support tower and a vertical axis wind turbine rotatably mounted on the support tower. A transmission and data acquisition assembly is connected to the bottom of the vertical axis wind turbine. The vertical axis wind turbine includes a data acquisition shaft and two hubs fixed on the data acquisition shaft. At least three upper support arms are fixed on one hub, and a lower support arm matching the number of upper support arms is fixed on the other hub. Straight blades are rotatably mounted between the corresponding upper and lower support arms. Both the upper and lower support arms are provided with blade mounting holes for mounting the straight blades. The straight blades are provided with vertical through holes, and blade shafts that mate with the blade mounting holes are provided in the vertical through holes. The straight blades are rotatably mounted between the upper and lower support arms via the blade shafts. At the bottom of each blade shaft, an independent pitch control mechanism is connected to the blade shaft. The independent pitch control mechanism is used to adjust the blade pitch angle of the straight blade.

[0006] Furthermore, the independent pitch mechanism includes a pitch servo fixed to the bottom of the lower support arm, and the servo arm of the pitch servo is fixedly connected to the bottom of the blade shaft through a pitch clamp.

[0007] Furthermore, the pitch fixture includes a bushing that is inserted into the bottom of the blade shaft and two connecting arms that are connected to the servo rocker arm. The two connecting arms are integrally formed with the bushing. A shaft fixing key is provided inside the bushing. Several rocker arm threaded holes are provided on the two connecting arms. A radial opening is provided on the bushing. Locking connecting plates are provided on both sides of the radial opening. Several shaft locking screws are correspondingly provided on the two locking connecting plates. An end face opening is provided on the bushing below the radial opening.

[0008] Furthermore, an angle sensor is connected to the top of the blade shaft.

[0009] Furthermore, blade radial bearings are provided at both the bottom and top of the blade shaft. One blade radial bearing is located between the top of the straight blade and the bottom of the upper support arm, and the other blade radial bearing is located between the bottom of the straight blade and the top of the lower support arm.

[0010] Furthermore, wire holes are provided at the top of the upper support arm, the bottom of the upper support arm, and the bottom of the lower support arm.

[0011] Furthermore, a servo mounting plate is provided inside the lower support arm, and a second single-tooth isolation post is fixed to the servo mounting plate by servo mounting plate screws. A servo mounting plate is fixed to the bottom of several second single-tooth isolation posts.

[0012] Furthermore, the angle sensor is fixedly connected to several first single-tooth isolation posts, and the several first single-tooth isolation posts are fixedly connected to the upper support arm.

[0013] Furthermore, the input shaft of the angle sensor is a square plug-in part, and the top of the blade shaft is provided with a square plug hole that mates with the square plug-in part. A retaining ring is fixed on the blade shaft.

[0014] Furthermore, a fixing ring is positioned between the angle sensor output end and the upper support arm.

[0015] Furthermore, a fixing ring is fixed on the blade shaft, and the fixing ring is located between the output end of the angle sensor and the upper support arm. A thrust bearing is installed between the input shaft of the angle sensor and the fixing ring.

[0016] The beneficial effects of this invention are as follows: This invention improves installation and maintenance convenience through modular design, optimizes the overall aerodynamic performance through independent pitch control, reduces the requirements for tower stiffness, and effectively improves the self-starting and power generation efficiency issues of vertical axis wind turbines.

[0017] This invention enables precise and independent control of the pitch angle of each blade in a micro vertical axis wind turbine by configuring an independent support, drive and monitoring system for each blade, thereby effectively improving the turbine's start-up performance, operating efficiency and overall stability.

[0018] This invention is installed on the rotor assembly of a micro vertical axis wind turbine, and each straight blade is individually equipped with independent pitch execution and monitoring components, including a blade rotation shaft, optical axis fixing ring, thrust bearing, tangential flange seated radial bearing, angle sensor, pitch servo, servo rocker arm and pitch clamp.

[0019] In this invention, the upper and lower support arms of the wind turbine assembly adopt a hollow tube structure with a flat elliptical cross-section. This facilitates the concealment of cables and reduces wind resistance. The internal arrangement of the pitch control components is optimized, and the cooperation between the thrust bearing and the radial bearing with a tangential flange seat reduces blade rotational friction, thereby lessening the load on the pitch servo. The pitch servo drives the blade rotation shaft to rotate via the servo rocker arm and pitch clamp. An angle sensor monitors the pitch angle in real time, and a hollow shaft slip ring enables power supply and signal transmission, thus achieving precise and independent control of the pitch angle of each blade.

[0020] This invention employs a modular, independent pitch mechanism, combined with a hollow support arm with a flat elliptical cross-section as an internal wiring channel, resulting in a more compact overall structure. This not only effectively reduces wind resistance but also greatly facilitates the installation, debugging, and subsequent maintenance of each component.

[0021] This invention achieves precise and independent closed-loop control of the pitch angle of each blade by configuring an independent drive and monitoring system that integrates a pitch servo, an angle sensor and a pitch clamp for each straight blade.

[0022] This invention enables the wind turbine to optimize the aerodynamic angle of attack of each blade in real time through the aforementioned independent pitch mechanism, thereby improving the starting torque, operating efficiency, and adaptive stability of the wind turbine under complex wind conditions, effectively solving the core problems of poor self-starting performance and low efficiency of vertical axis wind turbines. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a micro variable pitch vertical axis wind turbine that applies an embodiment of the present invention. Figure 2 This is a schematic diagram of the installation of an independent pitch mechanism for a micro variable pitch vertical axis wind turbine blade along the tangential direction of the support arm. Figure 3 This is a schematic diagram of the installation of an independent pitch mechanism for a micro-pitch vertical axis wind turbine blade along the normal direction of the support arm. Figure 4 For the present invention Figure 3 Partial cross-sectional view of AA in the middle; Figure 5 This is a front view of the pitch clamp of the present invention; Figure 6 This is a top view of the pitch clamp of the present invention; Figure 7This is a schematic diagram of the transmission and acquisition component in this invention; Figure 8 This is a schematic diagram of the control flow of the present invention.

[0024] The symbols for the main components in the diagram are explained below: 1. Vertical axis impeller; 11. Straight blades; 121. Upper support arm; 122. Lower support arm; 1221. Cable hole; 13. Hub; 14. Independent pitch mechanism; 140. Servo mounting plate; 1401. Servo mounting plate screw; 141. Pitch servo; 142. Servo mounting plate; 143. Servo rocker arm; 144. Pitch clamp; 1441. Rocker arm threaded hole; 1442. Shaft locking screw; 1443. Shaft fixing key; 145. Blade radial bearing; 146. Blade shaft; 147. Thrust bearing; 148. Retaining ring; 149. Angle sensor; 151. First single-tooth isolation post; 152. Second single-tooth isolation post; 2. Support tower; 3. Transmission and acquisition components; 31. Drive shaft; 32. Hollow shaft slip ring; 33. Drive shaft radial bearing; 34. Drive shaft thrust bearing; 35. Rotary encoder; 36. Plum blossom coupling; 37. Torque sensor; 38. Generator motor; 41. PLC controller; 42. High-speed pulse conversion module. Detailed Implementation

[0025] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0026] like Figure 1As shown, the micro vertical axis wind turbine with independent blade pitch includes a support tower 2 and a vertical axis wind turbine 1 rotatably mounted on the support tower 2. The support tower 2 is fixed to the foundation by a bolted connection structure and is used to support the vertical axis wind turbine assembly 1 and install the transmission and acquisition assembly 3. The transmission and acquisition assembly 3 is connected to the bottom of the vertical axis wind turbine 1. The vertical axis wind turbine 1 includes an acquisition shaft and two hubs 13 fixed on the acquisition shaft. At least three upper support arms 121 are fixed on one hub 13, and a number of lower support arms 122 matching the number of upper support arms 121 are fixed on another hub 13. Straight blades 11 are rotatably arranged between the corresponding upper support arms 121 and lower support arms 122. In this embodiment, there are three upper support arms 121, three lower support arms 122, and three straight blades 11, with each upper support arm 121 distributed at 120° intervals. Both the upper support arm 121 and the lower support arm 122 are provided with blade mounting holes for mounting straight blades 11. Each straight blade 11 has a vertical through hole, within which a blade shaft 146 mates with the blade mounting hole. The straight blade 11 is rotatably mounted between the upper support arm 121 and the lower support arm 122 via the blade shaft 146. Both the upper support arm 121 and the lower support arm 122 are hollow tubes with a flat elliptical cross-section, forming internal channels for cable routing. The acquisition shaft is connected to the drive shaft 31 of the transmission acquisition assembly 3, transferring the mechanical energy of the wind turbine to the generator.

[0027] like Figure 2 and Figure 3 As shown, each blade shaft 146 has an independent pitch mechanism 14 connected to its bottom. The independent pitch mechanism 14 is used to adjust the blade pitch angle of the straight blade 11. Each straight blade 11 is mounted on the support arm via an independent pitch mechanism 14, thereby achieving independent pitch angle control. The independent pitch mechanism 14 includes a pitch servo 141 fixed to the bottom of the lower support arm 122. The servo arm 143 of the pitch servo 141 is fixedly connected to the bottom of the blade shaft 146 via a pitch clamp 144. The core of the independent pitch mechanism 14 lies in the support of the blade shaft 146 and the drive of the pitch servo 141. The upper and lower shafts 146 pass through the upper support arm 121 and the lower support arm 122 respectively. The specific installation path is as follows: from top to bottom, they pass through the retaining ring 148, the thrust bearing 147, the upper support arm 121, the blade radial bearing 145, the straight blade 11, and finally exit through the lower support arm 122.

[0028] like Figure 4 , Figure 5 and Figure 6As shown, the pitch clamp 144 includes a plug-in bushing that engages with the lower rotating shaft 146 and two connecting arms that connect with the servo rocker arm 143. The two connecting arms are integrally formed with the plug-in bushing. A rotating shaft fixing key 1443 is provided inside the plug-in bushing. Several rocker arm threaded holes 1441 are provided on the two connecting arms. A radial opening is provided on the plug-in bushing, and locking connecting plates are provided on both sides of the radial opening. Several rotating shaft locking screws 1442 are correspondingly provided on the two locking connecting plates. An end face opening is provided below the radial opening on the plug-in bushing. The hub end of the pitch clamp 144 is provided with a rotating shaft fixing key 1443 and clamping rotating shaft locking screws 1442, forming a dual connection of "key connection + clamping fixation" with the keyway at the end of the lower rotating shaft 146. This connection method ensures reliable transmission of drive torque and allows for precise setting of the initial installation angle of the blades. The power and signal lines of the pitch servo 141 enter the internal cavity of the support arm through the wire hole 1221 on the lower surface of the lower support arm 122, and then are led to the hollow shaft slip ring 32 via the hub 13.

[0029] An angle sensor 149 is connected to the top of the blade shaft 146. Real-time monitoring of the blade pitch angle is achieved through the angle sensor 149. Figure 2 Angle sensor 149 is fixedly mounted on the top of upper support arm 121 via a first single-tooth isolation post 151. The input shaft of angle sensor 149 is coaxial with the blade rotation shaft 146. The top of the input shaft of angle sensor 149 adopts a square structure, and the input shaft of angle sensor 149 is keyed to the fixing ring 148 to accurately sense its rotation angle. The cable of angle sensor 149 passes through the cavity inside upper support arm 121 and hub 13, and finally connects to the hollow shaft slip ring 32 installed on the extended end of drive shaft 31 to realize continuous transmission of monitoring signals.

[0030] Angle sensor 149 is fixedly connected to several first single-tooth isolation posts 151, which are fixedly connected to upper support arm 121 by nuts. The input shaft of angle sensor 149 is a square plug-in part, and the top of blade shaft 146 is provided with a square insertion hole that mates with the square plug-in part. A fixing ring 148 is fixed on blade shaft 146. The fixing ring 148 is located between the output end of angle sensor 149 and upper support arm 121. The fixing ring 148 is provided with a fastening threaded hole, and a fastening adjusting screw is provided in the fastening threaded hole.

[0031] A thrust bearing 147 is provided between the input shaft of the angle sensor 149 and the fixed ring 148. Blade radial bearings 145 are provided at both the bottom and top of the blade shaft 146. These blade radial bearings 145 are preferably truncated flange radial bearings with seats. One blade radial bearing 145 is located between the top of the straight blade 11 and the bottom of the upper support arm 121, and the other blade radial bearing 145 is located between the bottom of the straight blade 11 and the top of the lower support arm 122. The two blade radial bearings 145, located on the upper support arm 121 and the lower support arm 122 respectively, are used to transmit aerodynamic and centrifugal forces. This combined design significantly reduces blade rotational friction and effectively reduces the load on the pitch control servo 141.

[0032] The upper support arm 121, lower support arm 122, straight blade 11, and data acquisition shaft all adopt a hollow structure. The top and bottom of the upper support arm 121 and the bottom of the lower support arm 122 are each provided with a wire hole 1221. The wire hole 1221 of the upper support arm 121 is used for the routing of the angle sensor 149, and the wire hole 1221 of the lower support arm 122 is used for the routing of the pitch servo 141. A hollow shaft slip ring 32 is provided between the data acquisition shaft and the support tower 2. The cable of the angle sensor 149 passes through the cavity inside the upper support arm 121 and the hub 13, and finally connects to the hollow shaft slip ring 32 installed on the extended end of the drive shaft 31, realizing continuous transmission of monitoring signals.

[0033] A servo mounting plate 140 is provided inside the lower support arm 122. The servo mounting plate 140 is fixed to a second single-tooth isolation post 152 by servo mounting plate screws 1401. The pitch mounting plate 140 is fixed to the top of the lower support arm 122 by the second single-tooth isolation post 152. A servo mounting plate 142 is fixed to the bottom of several second single-tooth isolation posts 152. The pitch servo 141 is fixed to the lower support arm by the second single-tooth isolation posts 152 and the servo mounting plate 140.

[0034] like Figure 7As shown, the transmission acquisition component 3 also includes a generator motor 38. Two radial bearings 33 and one thrust bearing 34 are installed between the transmission shaft 31 and the support tower 2. The bottom of the transmission shaft 31 is connected to the input shaft of the motor 38 via a perforated coupling 36. A dynamic torque sensor 37 is also installed at the bottom of the transmission shaft 31, preferably a dynamic torque sensor. A rotary encoder 35 is installed between the middle of the transmission shaft 31 and the support tower 2, preferably a hollow shaft rotary encoder. Specifically, under wind power, the straight blades 11 drive the hub 13 and the transmission shaft 31 to rotate, converting wind energy into mechanical energy. The transmission shaft 31 drives the input shaft of the generator motor 38 to rotate, converting mechanical energy into electrical energy. The vertical axis wind turbine structure has the advantage of multi-directional wind reception, and each device can be placed at the bottom, offering advantages of light weight and a low center of gravity, reducing the rigidity requirements of the tower while ensuring the stability of the overall system.

[0035] like Figure 8 As shown, it also includes a PLC controller 41 and a high-speed pulse conversion module 42. The PLC controller 41 of this invention can realize open-loop or closed-loop PID control to achieve variable pitch control of the blades. The outer ring of the rotary encoder 35 is fixed on the support tower 2, and the inner ring rotates with the drive shaft. Each rotation sends a fixed number of N pulses to the PLC. The PLC controller 41 receives the pulses through a high-speed counter and determines the azimuth angle of the straight blade 11 by the number of received pulses. That is, (0, N) pulses correspond to an azimuth angle of (0, 360) degrees. When the number of pulses reaches N, it is reset to ensure the correspondence between the number of pulses and the azimuth angle.

[0036] In this invention, there are preferably three straight blades 11, namely a first straight blade 111, a second straight blade 112, and a third straight blade 113, and their corresponding pitch servos 141 are the first pitch servo 1411, the second pitch servo 1412, and the third pitch servo 1413, respectively. If the initial position of the first straight blade 111 is at 0 degrees azimuth, the azimuth angle of the first straight blade 111 can be determined by the number of pulses received by the PLC controller 41. After the azimuth angle of the first straight blade 111 is determined, the positions of the second straight blade 112, which is 120 degrees different from the first straight blade 111 in its installation position, and the third straight blade 113, which is 240 degrees different from the first straight blade in its installation position, are also determined.

[0037] Furthermore, an event interrupt module is set in the PLC controller 41. The interrupt event trigger condition is the number of pulses corresponding to the required pitch angle of the straight blade 11. After the set number of pulses is reached, the interrupt is triggered. In the interrupt program, the rotation angle control of the first pitch servo 1411, the second pitch servo 1412, and the third pitch servo 1413 is performed.

[0038] Furthermore, the pitch servo 141 is preferably a digital servo. The PWM wave is used in the event interrupt module of the PLC controller 41 to control the rotation angle of the servo. The PWM wave period of the pitch servo 141 is 20ms, and the pulse width (0.5, 2.5) milliseconds corresponds to the rotation angle (-180, 180) degrees. The PLC signal is converted into a TTL signal by the high-speed pulse conversion module 42 and then sent to the pitch servo 141. The pitch servo 141 completes the pitch operation according to the signal.

[0039] Furthermore, combined Figure 8 The PLC controller 41 acquires azimuth and propeller angle data. For high-speed data acquisition, taking a 10ms acquisition interval as an example, a loop interrupt module is set to enter every 10ms. This loop interrupt module records the azimuth and propeller angle of the straight blade 11, i.e., the pulse count of the rotary encoder 35 and the angle recorded by the angle sensor 149. Each time the loop interrupt is entered, data is recorded and stored in a temporary storage area. A total of 100 temporary storage areas are set. When all 100 temporary storage areas are full (after 1 second), the data from all 100 temporary storage areas is stored together in the data log of the PLC controller 41 or transmitted to a host computer such as a touchscreen or computer. In the next 1 second, new data is used to replace the data in each temporary storage area, and the data is uploaded again after the temporary storage areas are full. This process is repeated to complete the high-speed data acquisition. If the acquisition frequency is more than 1 second, the data in the PLC controller 41 can be directly stored in the data log or transmitted to the host computer in the main program.

[0040] The variable pitch vertical axis wind turbine and its pitch control scheme described above have the advantages of simple structure, ease of manufacturing and maintenance. Based on a PLC-based control scheme, the pitch angle can be flexibly adjusted to different azimuth angles. It boasts advantages such as product maturity, fast pitch response, ease of operation, and strong adaptability. This patented variable pitch vertical axis wind turbine and its pitch control scheme can flexibly adjust blade pitch to improve the starting performance of the vertical axis wind turbine, power generation efficiency below rated wind speed, load control above rated wind speed, and aerodynamic braking using blade pitch when the cutoff wind speed is reached, giving the vertical axis wind turbine better aerodynamic and safety performance.

Claims

1. A micro vertical axis wind turbine with individual blade pitch, characterized in that, The vertical axis wind wheel (1) is connected with a transmission and collection assembly (3) at the bottom. The vertical axis wind wheel (1) comprises a collection rotating shaft and two hubs (13) fixed on the collection rotating shaft, one of the hubs (13) is fixed with at least three upper support arms (121), and the other hub (13) is fixed with lower support arms (122) matched with the number of the upper support arms (121), and straight blades (11) are rotationally arranged between the corresponding upper support arms (121) and lower support arms (122). The upper support arms (121) and the lower support arms (122) are provided with blade mounting holes for mounting the straight blades (11), the straight blades (11) are provided with vertical through holes, the vertical through holes are provided with blade rotating shafts (146) matched with the blade mounting holes, the straight blades (11) are rotationally mounted between the upper support arms (121) and the lower support arms (122) through the blade rotating shafts (146), and the bottom of each blade rotating shaft (146) is connected with an independent variable pitch mechanism (14).

2. The blade independent variable pitch micro-hydrokinetic wind turbine of claim 1, wherein, The independent variable pitch mechanism (14) comprises a variable pitch steering engine (141) fixed at the bottom of the lower support arm (122), and a steering engine rocker arm (143) of the variable pitch steering engine (141) is fixedly connected with the bottom of the blade rotating shaft (146) through a variable pitch clamp (144).

3. The blade independent variable pitch micro-hydrokinetic wind turbine of claim 2, wherein, The variable pitch clamp (144) comprises a plug-in shaft sleeve matched with the bottom of the blade rotating shaft (146) and two connecting arms connected with the steering engine rocker arm (143), the two connecting arms are integrally formed with the plug-in shaft sleeve, a rotating shaft fixing key (1443) is arranged in the plug-in shaft sleeve, a plurality of swing arm threaded holes (1441) are arranged on the two connecting arms, a radial opening is arranged on the plug-in shaft sleeve, locking connecting plates are arranged on the two sides of the radial opening, a plurality of rotating shaft locking screws (1442) are arranged on the two locking connecting plates in correspondence, and an end face opening is arranged below the radial opening of the plug-in shaft sleeve.

4. The blade independent variable pitch micro-hydrokinetic wind turbine of claim 1, wherein, An angle sensor (149) is connected to the top of the blade rotating shaft (146).

5. The blade independent variable pitch micro-hydrokinetic wind turbine of claim 1, wherein, The bottom and the top of the blade rotating shaft (146) are provided with blade radial bearings (145), one of the blade radial bearings (145) is located between the top of the straight blade (11) and the bottom of the upper support arm (121), and the other blade radial bearing (145) is located between the bottom of the straight blade (11) and the top of the lower support arm (122).

6. The blade independent variable pitch micro-hydrokinetic wind turbine of claim 1, wherein, Wire holes (1221) are arranged at the top of the upper support arm (121), the bottom of the upper support arm (121) and the bottom of the lower support arm (122).

7. The blade independent variable pitch micro-hydrokinetic wind turbine of claim 2, wherein, A steering engine fixing plate (140) is arranged in the lower support arm (122), the steering engine fixing plate (140) is fixed with second single-head tooth isolation columns (152) through steering engine fixing plate screws (1401), and the bottoms of the second single-head tooth isolation columns (152) are fixed with a steering engine mounting plate (142).

8. The blade independent variable pitch micro-hydrokinetic wind turbine of claim 4, wherein, The angle sensor (149) is fixedly connected with a plurality of first single-head tooth isolation columns (151), and the plurality of first single-head tooth isolation columns (151) are fixedly connected with the upper support arm (121).

9. The blade independent variable pitch micro-hydrokinetic wind turbine of claim 4, wherein, The input shaft of the angle sensor (149) is a square plug, and the top of the blade rotating shaft (146) is provided with a square socket matched with the square plug.

10. The blade independent variable pitch micro-hydrokinetic wind turbine of claim 9, wherein, The blade rotating shaft (146) is fixedly connected with a fixing ring (148), the fixing ring (148) is arranged between the output end of the angle sensor (149) and the upper support arm (121), and a thrust bearing (147) is arranged between the input shaft of the angle sensor (149) and the fixing ring (148).

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