An automatic pitch-adjusting system for wind turbine blades

Abstract

This invention provides an automatic pitch calibration system for wind turbine blades. The system consists of a proximity switch installed at a preset mark at a mechanical 49° position at the blade root, with its centerline coinciding with the mark; a limit stop fixed at the blade root and moving with the blade through the proximity switch's sensing area; a pulse signal triggering module that generates a calibration pulse signal when the limit stop enters the sensing area; and an angle forced correction module that forcibly adjusts the rotary encoder angle in the pitch control system to the preset 49° mechanical position in response to the calibration pulse signal. The closest gap between the proximity switch and the limit stop is precisely set to 3mm, ensuring triggering accuracy while preventing mechanical collisions. The system triggers a calibration pulse signal once each during blade opening and closing to correct the rotary encoder angle in real time. The 49° mechanical position is used as an intermediate calibration point to eliminate accumulated angle errors. Furthermore, the system is integrated into the pitch control system, eliminating the need for an additional control unit.

Description

Technical Field

[0001] This utility model relates to the field of wind power generation technology, and more specifically, to an automatic blade calibration system for wind turbines. Background Technology

[0002] Our company uses an electric pitch control system from SSB, Germany, with a toothed belt drive. The blade rotation angle range is 0-90°, with a retractable position of 87° and a feathering position of 0°. There are two mechanical limits of 95° and 5°, using lever-type limit switches. The blade angle is detected and determined by a rotary encoder installed at the end of the pitch drive motor. During normal operation, the blades reciprocate within the 87° to 0° range. Over extended periods, the rotary encoder may deviate from the actual mechanical position angle. When this deviation exceeds a certain value, it can lead to inconsistent or distorted blade angles, causing abnormal turbine operation, downtime, or reduced output. In severe cases, it can even lead to retractable blade failure and subsequent secondary safety incidents. When the pitch encoder deviates from the actual mechanical position angle, manual calibration of the rotary encoder within the hub is required. This work is not only highly dangerous but also time-consuming and labor-intensive, significantly impacting the wind turbine's operating efficiency. Utility Model Content

[0003] Based on the above-mentioned technical problems, this utility model proposes an automatic blade calibration system for wind turbines.

[0004] An automatic pitch adjustment system for wind turbine blades, comprising:

[0005] A proximity switch is installed at a preset mark at a mechanical 49° position at the root of the propeller blade, with the center line of the proximity switch coinciding with the mark at the 49° mechanical position.

[0006] A limit stop plate is fixed to the root of the propeller blade and passes through the sensing area of ​​the proximity switch as the propeller blade rotates.

[0007] A pulse signal triggering module is used to generate a calibration pulse signal when the limit stop plate enters the sensing area of ​​the proximity switch;

[0008] The angle forced correction module, in response to the calibration pulse signal, forcibly adjusts the angle of the rotary encoder in the pitch control system to a preset mechanical position of 49°.

[0009] The closest gap between the proximity switch and the limit stop is 3mm to ensure triggering accuracy and avoid mechanical collision.

[0010] Preferably, the installation position of the proximity switch is determined through on-site simulation testing and is calibrated synchronously with the limit stop of the blade.

[0011] Preferably, the calibration pulse signal is triggered once each during the propeller opening and closing processes to ensure real-time correction of the rotary encoder angle.

[0012] Preferably, the preset 49° mechanical position is the intermediate calibration point in the blade operating range, used to eliminate encoder angle cumulative error.

[0013] Preferably, the system is integrated into the wind turbine pitch control system, eliminating the need for an additional control unit.

[0014] Beneficial effects:

[0015] 1. Enhanced safety: This invention enables automatic calibration of blade angles, greatly reducing the safety risks associated with manual tower climbing for blade angle calibration. In the past, manual tower climbing operations required workers to face various dangers such as falls from heights, electric shocks, and equipment collisions. The application of this system eliminates the need for workers to perform such high-risk operations, fundamentally protecting their lives.

[0016] 2. Increased Efficiency: The system significantly reduces workload and time. Traditional manual calibration of rotary encoders to their actual mechanical positions requires a significant investment of time and effort from skilled technicians and often results in prolonged wind turbine downtime. This system's automatic calibration function saves substantial manpower and time, enabling wind turbines to resume normal operation more quickly, reducing power generation losses due to downtime calibration, and significantly improving both work efficiency and power generation efficiency.

[0017] 3. Enhanced Stability: By triggering a calibration pulse signal once during the blade opening and retraction processes, and setting the 49° mechanical position as the intermediate calibration point, the cumulative error of the encoder angle can be eliminated in real time and effectively, ensuring high accuracy in blade angle detection. This ensures that the angles of the three blades remain consistent, avoiding abnormal wind turbine operation caused by angle deviations, such as excessive vibration and reduced power generation efficiency. This improves the stability and reliability of wind turbine operation, guarantees continuous and efficient power generation, and ultimately enhances the economic benefits of the entire wind power generation system. Attached Figure Description

[0018] Figure 1 A schematic diagram of the structure of this utility model is shown;

[0019] In the attached diagram, 1 is the propeller, 2 is the proximity switch, 3 is the pulse signal triggering module, 4 is the angle forced correction module, and 5 is the rotary encoder. Detailed Implementation

[0020] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0021] like Figure 1 The automatic blade calibration system for a wind turbine is shown, which includes a proximity switch 2, a pulse signal triggering module 3, and an angle forced correction module 4.

[0022] Proximity switch 2: The proximity switch 2 of this system is installed at a preset mark at the mechanical 49° position at the root of blade 1, and its center line precisely coincides with the mark at this mechanical 49° position. Proximity switch 2 plays a key position sensing role at this location. By installing it at this specific position, it can accurately monitor the position reached by blade 1 during rotation. Its installation position was determined through rigorous on-site simulation tests. By simulating the rotation of blade 1 under different wind speeds and operating conditions, and combining a large amount of data collection and analysis, the installation point that can most accurately sense the position of blade 1 was found, ensuring that it can stably and accurately capture the position information of blade 1 under various conditions. At the same time, proximity switch 2 needs to be synchronously calibrated with the limit baffle of blade 1. This means that during the system installation and commissioning phase, it is necessary to ensure a high degree of matching between proximity switch 2 and limit baffle in terms of spatial position and operating rhythm, so as to improve the accuracy and reliability of the system's detection of blade 1 position and avoid signal errors caused by asynchrony between the two.

[0023] Limiting baffle: The limiting baffle is firmly fixed to the root of blade 1, forming an integral part with blade 1. It rotates synchronously with blade 1. When blade 1 rotates, the limiting baffle passes through the sensing area of ​​proximity switch 2. The limiting baffle acts as a signal trigger. When it enters the sensing range of proximity switch 2, it triggers a series of subsequent operations, providing the necessary triggering conditions for the correction of blade 1 angle. Its design of being fixed to the root of blade 1 ensures consistency with the movement of blade 1 and will not affect the accurate triggering of the signal due to loosening or displacement, thus ensuring the stability and reliability of system signal transmission.

[0024] Pulse signal triggering module 3: When the limit stop enters the sensing area of ​​proximity switch 2, the pulse signal triggering module 3 starts to function. Once the module receives the signal that the limit stop has entered the sensing area, it will quickly and accurately generate a calibration pulse signal. The calibration pulse signal provides the necessary signal support for the subsequent angle forced correction operation, so that all parts of the system can work together in a preset logical order to ensure the continuity and accuracy of the entire calibration process.

[0025] Angle forced correction module 4: This module is the core component of the entire system to achieve precise angle correction of blade 1. It responds to the calibration pulse signal from the pulse signal trigger module 3. It is the pitch controller in the pitch control system. That is, the pitch controller controls the angle of the rotary encoder 5 to be adjusted to the preset 49° mechanical position by receiving the calibration pulse signal received by the pitch control system. After receiving the calibration pulse signal, the angle forced correction module 4 quickly and accurately adjusts the angle of the rotary encoder 5 through a precise algorithm and control mechanism, thereby effectively eliminating the deviation between the angle of the rotary encoder 5 and the actual mechanical position angle caused by long-term operation, ensuring the high accuracy of blade 1 angle detection, so that the blade 1 of the wind turbine can always maintain the accurate angle position.

[0026] Furthermore, in the system design, the minimum clearance between proximity switch 2 and the limit stop is set to 3mm. This precise clearance setting is of great significance; on the one hand, the 3mm clearance ensures triggering accuracy, allowing proximity switch 2 to detect and trigger the signal promptly and accurately when the limit stop approaches the appropriate distance. If the clearance is too large, the signal triggering may be insensitive, failing to capture the position information of blade 1 in time; if the clearance is too small, it may easily cause false triggering, affecting the normal operation of the system. On the other hand, this clearance size can effectively prevent mechanical collisions between proximity switch 2 and the limit stop during the rotation of blade 1, thereby ensuring the safe operation of all components of the system and extending the service life of the equipment.

[0027] This system also has unique operating characteristics: the calibration pulse signal is triggered once during the opening and retraction of blade 1. When blade 1 opens, the calibration pulse signal is triggered and the angle is corrected, which can ensure the accuracy of the opening angle of blade 1, so that blade 1 can capture wind energy at the optimal angle and improve the power generation efficiency of wind turbine. The correction is also triggered during the retraction process, which can ensure that blade 1 returns to the predetermined retraction position accurately, avoid abnormal retraction due to angle deviation, and ensure the safe shutdown of wind turbine.

[0028] Setting the preset 49° mechanical position as the intermediate calibration point in the operating range of blade 1 is a scientifically sound approach: the rotation angle range of blade 1 is 0-90°, the retracted position is 87°, the feathering position is 0°, and there is a mechanical limit of 95°. 49° is in the middle position, and using this as the calibration point can effectively eliminate the cumulative angle error of the encoder throughout the entire operating range.

[0029] This system is integrated into the pitch control system of the wind turbine, eliminating the need for additional control units. This integrated design not only simplifies the system structure and reduces the number of hardware devices, thereby lowering hardware costs, but also reduces potential failure points caused by additional control units, improving the overall stability and compatibility of the system. This allows the system to better integrate into existing wind power equipment systems and work in conjunction with other components.

[0030] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An automatic pitch adjustment system for wind turbine blades, characterized in that, include: A proximity switch is installed at a preset mark at a mechanical 49° position at the root of the propeller blade, with the center line of the proximity switch coinciding with the mark at the 49° mechanical position. A limit stop plate is fixed to the root of the propeller blade and passes through the sensing area of ​​the proximity switch as the propeller blade rotates. A pulse signal triggering module is used to generate a calibration pulse signal when the limit stop plate enters the sensing area of ​​the proximity switch; The angle forced correction module, in response to the calibration pulse signal, forcibly adjusts the angle of the rotary encoder in the pitch control system to a preset mechanical position of 49°. The closest gap between the proximity switch and the limit stop is 3mm to ensure triggering accuracy and avoid mechanical collision.

2. The automatic pitch adjustment system for wind turbine blades according to claim 1, characterized in that, The installation position of the proximity switch was determined through on-site simulation testing and was synchronously calibrated with the limit stop of the blade.

3. The automatic pitch adjustment system for wind turbine blades according to claim 1, characterized in that, The calibration pulse signal is triggered once each during the propeller opening and closing processes to ensure real-time correction of the rotary encoder angle.

4. The automatic pitch adjustment system for wind turbine blades according to claim 1, characterized in that, The preset 49° mechanical position is the intermediate calibration point in the blade operating range, used to eliminate encoder angle cumulative error.

5. The automatic pitch adjustment system for wind turbine blades according to claim 1, characterized in that, The system is integrated into the wind turbine pitch control system and requires no additional control unit.

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