A wind power variable pitch positioning method, device and medium

Abstract

The present application relates to wind power variable pitch control technical field, disclose a kind of wind power variable pitch positioning method, device and medium, the present application when blade enters the preset angle range with target angle as center, record the positive angle detection value of blade, and control variable pitch motor reverse rotation, obtain the reverse angle detection value of blade at theoretical complementary position in reverse stroke;Comprehensive determination is carried out based on positive angle detection value and reverse angle detection value, when meeting determination condition, confirm that blade reaches target position, execute shutdown operation;Determination condition includes: the sum of positive angle detection value and reverse angle detection value is equal to full range angle.The present application realizes the two-way compensation of overstroke error and the accurate confirmation of parking position by introducing the two-way cross verification mechanism of full range angle symmetry mapping.

Description

Technical Field

[0001] This invention relates to the field of wind power pitch control technology, specifically to a wind power pitch positioning method, device, and medium. Background Technology

[0002] In wind turbine pitch control systems, the precision of feathering operation is crucial for turbine safety. When a shutdown is required, the pitch control system drives the blades to the feathering position (typically 90°) to reduce the wind-receiving area of ​​the rotor, decrease blade load, and ensure turbine safety. Existing pitch control systems generally use a 91° limit switch as the feathering completion signal. However, due to factors such as mechanical tolerances, control precision, motor inertia, and signal response delays, the actual stopping position of the blades often exceeds the 90° target value, resulting in overtravel issues, typically falling between 91° and 93°.

[0003] To address the overtravel issue, the traditional solution moves the limit switch's installation position from the theoretical feathering angle of 90° to 91°, allowing for approximately 1° of overtravel margin. When the blade touches the limit switch, the shutdown and brake-engaging logic is executed. However, this solution still has the following drawbacks: First, the one-way compensation does not solve the fundamental error. The reserved overtravel margin can only compensate for the inertial overshoot in the positive direction (large angle direction), but there is no corresponding compensation for the tolerance and control delay in the reverse direction (small angle direction), resulting in bidirectional asymmetry, and the actual stopping position still fluctuates by more than ±0.5°.

[0004] Second, it relies on a single signal source and lacks cross-validation. Traditional solutions rely solely on the edge signal of the 91° limit switch for stopping the machine, without any other independent information source to verify the accuracy of this position, posing a risk of single-point failure. Summary of the Invention

[0005] This invention provides a wind turbine pitch control positioning method, device, and medium. Based on a full-range angular symmetric mapping relationship, it achieves precise positioning and confirmation of the blade's docking position, solving the problem of limit switch overtravel error caused by factors such as mechanical tolerances, control precision, inertia, and response delay in existing pitch control systems, as well as the problems of incomplete unidirectional compensation and lack of cross-verification in traditional solutions. This invention introduces logic for mutual verification of forward and reverse angles, achieving bidirectional compensation for overtravel error and precise confirmation of the docking position.

[0006] In a first aspect, the present invention provides a wind turbine pitch positioning method, comprising: controlling a pitch motor to rotate forward, driving the blades to move towards a target angle; when the blades enter a preset angle range centered on the target angle, recording the forward angle detection value of the blades, and controlling the pitch motor to rotate in the reverse direction, obtaining the reverse angle detection value of the blades at the theoretical complementary position during the reverse stroke; wherein, the angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle; making a comprehensive judgment based on the forward angle detection value and the reverse angle detection value, and confirming that the blades have reached the target position when the judgment condition is met, and performing a shutdown operation; the judgment condition includes: the sum of the forward angle detection value and the reverse angle detection value is equal to the full-range angle.

[0007] This invention introduces a bidirectional cross-verification mechanism with full-range angular symmetry mapping. Utilizing the fixed 360° full-range characteristic of a single rotation of the pitch motor, it maps the target angle reached by forward feathering to the theoretical complementary angle during reverse rotation. By verifying whether the sum of the angle detection values ​​in both directions equals 360°, bidirectional redundancy verification of the blade's stopping position is achieved. Compared with existing technologies, this invention overcomes the limitation of traditional schemes that only compensate for forward inertial overshoot in a single direction. By cross-verifying forward and reverse angles, it simultaneously eliminates errors in both forward overtravel and reverse tolerance, achieving bidirectional symmetrical compensation and improving feathering accuracy. Furthermore, by introducing forward and reverse readings as two independent information sources for cross-verification, this invention effectively avoids the single-point failure risk associated with a single limit switch signal source, significantly improving the reliability of pitch positioning.

[0008] In one optional implementation, the target angle is 90°, and the angle corresponding to the theoretical complementary position is 270°. This implementation utilizes the full-range characteristic of the pitch motor's 360° single-cycle stroke to establish a strict geometric symmetry between the forward feathering positioning angle and the reverse complementary angle. When the blade reaches approximately 90° in the forward direction, it rotates in the reverse direction to approximately 270° to obtain the reverse angle detection value. If the sum of the two values ​​equals 360°, the positioning is considered accurate. The mapping relationship between 90° and 270° fully utilizes the fixed full-range characteristic of the motor's single-cycle stroke, mapping any forward target angle to a uniquely determined reverse complementary angle. When overshoot occurs in the forward direction due to inertia or other factors, the reverse angle detection value will synchronously deviate from the theoretical complementary position. The overtravel error can be accurately identified by the deviation of the sum of the two values ​​from 360°, thereby triggering timely correction or alarm when the actual docking position deviates from the target angle, effectively preventing the blade from exceeding the safe range due to overtravel and ensuring the safe operation of the unit. This angle mapping relationship transforms the positive positioning verification of the target angle into a symmetrical mutual verification in both directions, enabling accurate identification and bidirectional compensation of overstroke error, and further improving the feathering positioning accuracy.

[0009] In one optional implementation, the preset angle range is an angle interval centered on the target angle with a deviation not exceeding ±0.5°. This implementation, by setting the preset angle range to an angle interval centered on the target angle with a deviation not exceeding ±0.5°, provides a clear trigger window for recording the forward angle detection value while ensuring the accuracy of feathering. When the blade enters this ±0.5° window range, forward angle recording is triggered. This avoids the response delay or signal jitter-induced recording lag caused by triggering recording only at the moment the target angle is reached. It also allows the controller to intervene and determine the position when the actual blade position deviates from the target angle but is still within the preset tolerance range, preventing the blade from continuing to move towards a larger angle due to inertia and increasing overtravel. This reduces the system's sensitivity to mechanical tolerances and control delays while ensuring accuracy, further improving the consistency and reliability of feathering. Simultaneously, this preset angle range provides an accurate data foundation for subsequent reverse verification steps, ensuring that the complementary verification relationship between the forward and reverse angle detection values ​​can be effectively established within a reasonable accuracy window, achieving accurate identification and compensation for overtravel errors.

[0010] In one optional implementation, when the sum of the forward angle detection value and the reverse angle detection value is not equal to the full-range angle, and the deviation is within a preset deviation range, a systematic bias error is determined to exist, and the systematic bias error is corrected. This implementation achieves accurate identification and correction of the systematic bias error of the measurement system by detecting the deviation of the sum of the forward and reverse angles relative to the full-range angle. When the sum of the forward angle detection value and the reverse angle detection value is not equal to 360° but the deviation is within the preset range, it indicates that the measurement system has a fixed zero-point offset or installation bias, rather than a random fault or sensor damage. This fundamentally avoids the cumulative positioning error caused by systematic problems such as sensor installation errors and mechanical zero-point offset, further improving the long-term stability and consistency of the pitch positioning method.

[0011] In one optional implementation, the preset deviation range is 0.3° to 0.5°. This implementation provides a reasonable tolerance window for determining systematic bias errors. This range can effectively distinguish between systematic bias errors and sensor malfunctions. When the deviation is within the range of 0.3° to 0.5°, it is determined to be a correctable systematic bias. When the deviation exceeds 0.5°, it is determined to be a sensor malfunction or an abnormal situation such as encoder slippage. This avoids the situation where normal measurement errors are misjudged as malfunctions and frequently trigger alarms due to an excessively small threshold setting, or where a real sensor malfunction is misjudged as a bias error due to an excessively large threshold setting, thus masking potential safety hazards.

[0012] In one optional implementation, if the deviation of the sum of the forward and reverse angle detection values ​​relative to the full-range angle exceeds a preset deviation range, encoder slippage or angle sensor malfunction is determined, triggering an alarm. This implementation achieves effective monitoring of sensor anomalies by setting a deviation threshold. When the deviation of the sum of the forward and reverse angles relative to the full-range angle exceeds a preset deviation range, encoder slippage or angle sensor malfunction is determined, and an alarm is triggered. Based on the geometric constraints of the full-range angle symmetry mapping, encoder slippage or sensor malfunction will inevitably cause the sum of the forward and reverse angles to deviate from 360°. This determination mechanism utilizes the inherent properties of angle mapping verification, enabling real-time monitoring of sensor health status without the need for additional hardware detection equipment. Once the deviation exceeds the preset deviation range, an alarm is triggered, effectively preventing position misjudgment due to sensor malfunction and further improving the safety and reliability of the pitch positioning system.

[0013] In an optional implementation, the method further includes: acquiring the electrical operating parameters of the pitch motor; the determination criteria further include: during the movement of the blade towards the target angle, the electrical operating parameters show a monotonically decreasing trend, and the electrical operating parameters are lower than a preset electrical threshold at the target angle. Traditional solutions do not consider the natural changes in torque and current of the motor as it approaches the target position, thus missing the opportunity to verify the accuracy of the mechanical position using electrical parameters. This implementation introduces the electrical operating parameters of the pitch motor as an auxiliary criterion, utilizing the physical characteristics that the aerodynamic load decreases and the motor torque and drive current decrease accordingly when the blade approaches a 90° feathering position. It independently verifies the accuracy of the mechanical position from an electrical perspective, achieving dual protection of mechanical detection and electrical verification. This effectively avoids misjudgment of position caused by the failure of a single angle signal source or mechanical jamming, further improving the reliability and safety of the pitch positioning system.

[0014] In one optional implementation, if the electrical operating parameters do not show a monotonically decreasing trend or do not fall below a preset electrical threshold at the target angle during the propeller's movement towards the target angle, mechanical jamming is determined to exist, triggering an alarm. This implementation utilizes the physical characteristics that the aerodynamic load decreases and the motor torque and drive current decrease accordingly when the propeller moves towards a 90° feathering position. Using the dynamic response of electrical parameters as the diagnostic basis, it achieves real-time monitoring of the health status of the mechanical transmission chain without adding additional hardware. It provides timely alarms before position misjudgments occur, reminding maintenance personnel to investigate and handle the issue, further improving the safety of the pitch positioning system.

[0015] Secondly, the present invention provides a wind turbine pitch positioning device, comprising: a blade motion module for controlling the pitch motor to rotate forward and drive the blade to move towards a target angle; an angle detection module for recording the forward angle detection value of the blade when the blade enters a preset angle range centered on the target angle, and controlling the pitch motor to rotate in the reverse direction to obtain the reverse angle detection value of the blade at the theoretical complementary position during the reverse stroke; wherein the angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle; and a position determination module for making a comprehensive determination based on the forward angle detection value and the reverse angle detection value, and confirming that the blade has reached the target position when the determination condition is met, and performing a shutdown operation; the determination condition includes: the sum of the forward angle detection value and the reverse angle detection value is equal to the full-range angle.

[0016] Thirdly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the wind turbine pitch positioning method of the first aspect or any corresponding embodiment described above. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic flowchart of the first method for wind turbine pitch positioning according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the second process of the wind turbine pitch positioning method according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the wind turbine blade pitch drive mechanism involved in the wind turbine pitch positioning method provided in this embodiment of the invention; Figure 4 This is a schematic diagram of the third process of the wind power pitch positioning method according to an embodiment of the present invention; Figure 5 This is a structural block diagram of a wind turbine pitch positioning device according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention; In this diagram, 1 represents the pitch motor, 2 represents the gearbox, 3 represents the connecting mechanism, and 4 represents the pinion. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. 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.

[0020] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Existing pitch control systems use a 91° limit switch as the feathering positioning signal, reserving overtravel margin by moving the limit switch installation position backward. However, this approach only compensates for positive inertial overshoot, lacking corresponding compensation for reverse tolerance and control delay, resulting in low docking accuracy and bidirectional asymmetry. Furthermore, this approach relies on a single limit switch edge signal, lacking an independent verification source and posing a single-point failure risk. Therefore, this invention provides a wind turbine pitch control positioning method, device, and medium to address the limit switch overtravel error problem caused by mechanical tolerances, control accuracy, inertia, and response delay in existing pitch control systems, as well as the incomplete unidirectional compensation and lack of cross-verification in traditional solutions. By introducing logic for mutual verification of forward and reverse angles, bidirectional compensation for overtravel error and accurate confirmation of docking position are achieved.

[0023] According to an embodiment of the present invention, a wind turbine pitch positioning method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0024] This embodiment provides a wind turbine pitch control positioning method. Figure 1 This is a flowchart of a wind turbine pitch positioning method according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps: Step S101: Control the pitch motor to rotate in the forward direction, driving the blades to move towards the target angle.

[0025] In the field of wind power pitch control, the pitch motor is an actuator used to drive the blades to rotate around their longitudinal axis to change the pitch angle. Motion is transmitted between the motor and the blades via a transmission mechanism. Forward rotation refers to the direction of motion that drives the blades to increase the pitch angle (i.e., the feathering direction), while the opposite is reverse rotation that decreases the pitch angle. In this step, the target angle refers to the predetermined pitch angle position that the blades should reach after feathering. In wind power pitch systems, this angle is typically 90°, at which point the blade surface is basically parallel to the wind direction, the aerodynamic load is minimized, and the unit is in a safe state.

[0026] This step is used to start the feathering process. By rotating the pitch motor in the forward direction, the blades are driven to gradually approach the target angle, creating the triggering conditions for recording the forward angle in step S102.

[0027] Step S102: When the blade enters the preset angle range centered on the target angle, record the forward angle detection value of the blade and control the pitch motor to rotate in the reverse direction. During the reverse stroke, obtain the reverse angle detection value of the blade at the theoretical complementary position. The angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle.

[0028] In this step, the preset angle range refers to an angle interval centered on the target angle, used to determine whether the blade has sufficiently approached the target angle to trigger subsequent recording and verification operations. When the blade enters this preset angle range, it indicates that the blade has reached the vicinity of the target angle. At this time, the current angle detection value is recorded as the forward angle detection value, which reflects the actual stopping position of the blade during the forward feathering process.

[0029] Simultaneously or after recording the forward angle detection value, the pitch motor is controlled to rotate in the reverse direction. This reverse rotation refers to a rotation opposite to the forward rotation direction in step S101, meaning the blades move in a direction that decreases the pitch angle. The purpose of the reverse rotation is to retract the blades from their forward position towards a smaller angle, in order to find the theoretical complementary position during the reverse stroke. The theoretical complementary position is the angular position that forms a complementary relationship with the target angle about the full-range angle; its corresponding angle value is the full-range angle minus the target angle. Based on the inherent characteristic that the pitch motor's single-cycle stroke is a fixed full-range angle, when the forward angle detection value equals the target angle, the angle value measured at the theoretical complementary position during the reverse stroke should, when summed with the target angle, equal the full-range angle.

[0030] The reverse angle detection value obtained during the reverse stroke is the angle value measured when the blade reaches the theoretical complementary position. This value, together with the forward angle detection value, constitutes a pair of angle data, which is used in subsequent steps to verify whether the sum of the two equals the full-range angle, thereby determining whether the blade has accurately reached the target position. This step, by introducing the detection of reverse rotation and theoretical complementary position, overcomes the limitation of traditional schemes that rely solely on unidirectional limit switch signals, introducing an independent cross-validation dimension for angle positioning.

[0031] It should be noted that the method for obtaining the reverse angle detection value during the reverse stroke can be either by continuously monitoring the angle sensor readings and recording them when they reach the theoretical complementary position, or by continuously acquiring angle values ​​during the reverse rotation and storing the corresponding data when the characteristics of the theoretical complementary position are identified. This step does not strictly limit the specific acquisition timing and recording method, as long as the angle value of the blade at the theoretical complementary position can be obtained during the reverse stroke. Regardless of the implementation method, as long as the reverse angle detection value corresponding to the theoretical complementary position is obtained during the reverse stroke, it falls within the scope of this step.

[0032] Step S103: Based on the forward angle detection value and the reverse angle detection value, a comprehensive judgment is made. If the judgment condition is met, it is confirmed that the blade has reached the target position and the shutdown operation is performed. The judgment condition includes: the sum of the forward angle detection value and the reverse angle detection value is equal to the full range angle.

[0033] This step involves comprehensive judgment, meaning that the forward and reverse angle detection values ​​are analyzed and evaluated as a whole, rather than considering either angle value in isolation. The theoretical basis for this judgment is that the single-cycle stroke of a pitch motor is a fixed full-range angle, forming a complete geometric cycle. At any angular position, the forward angle detection value and the corresponding reverse angle detection value within the full-range cycle always satisfy a complementary constraint relationship. When the blade accurately reaches the target angle, the forward angle detection value should be consistent with the target angle, and the angle value measured at the theoretical complementary position during the reverse stroke should also be equal to the theoretical complementary angle; the sum of the two must equal the full-range angle. Conversely, when the blade overtravels due to mechanical tolerances, inertia, or response delays, the forward angle detection value will deviate from the target angle, and the reverse angle detection value will also deviate synchronously from the theoretical complementary angle; the sum of the two will not equal the full-range angle, and the magnitude of the deviation directly reflects the degree of overtravel error. Therefore, by verifying whether the sum of the forward angle detection value and the reverse angle detection value is equal to the full-range angle, it can be determined whether the blade has accurately reached the target position.

[0034] This judgment mechanism is based solely on the inherent full-range angular characteristics of the pitch motor, thus possessing inherent reliability and self-consistency. Any deviation in the detected angle value, whether stemming from forward overtravel, reverse positioning error, or sensor measurement error, will cause the sum of these two deviations from the full-range angle, thus ensuring accurate identification. When the judgment condition is met, it is confirmed that the blades have accurately reached the target position, and a shutdown operation is performed. This achieves precise docking control based on bidirectional cross-validation, effectively eliminating overtravel errors caused by unidirectional detection.

[0035] The wind turbine pitch positioning method provided in this embodiment introduces a bidirectional cross-verification mechanism with full-range symmetrical angle mapping. Utilizing the fixed full-range characteristic of the pitch motor's 360° single-rotation, the target angle reached by forward feathering is mapped to the theoretical complementary angle during reverse rotation. By verifying whether the sum of the angle detection values ​​in both directions equals 360°, bidirectional redundancy verification of the blade's stopping position is achieved. Compared with existing technologies, this invention overcomes the limitation of traditional schemes that only compensate for forward inertial overshoot in a single direction. By cross-verifying forward and reverse angles, it simultaneously eliminates errors in both forward overtravel and reverse tolerance, achieving bidirectional symmetrical compensation and improving feathering accuracy. Furthermore, this invention introduces forward and reverse readings as two independent information sources for cross-verification, effectively avoiding the single-point failure risk associated with a single limit switch signal source and significantly improving the reliability of pitch positioning.

[0036] This embodiment provides another wind turbine pitch positioning method. Figure 2 This is a flowchart of a wind turbine pitch positioning method according to an embodiment of the present invention, such as... Figure 2 As shown, the process includes the following steps: Step S201: Control the pitch motor to rotate in the forward direction, driving the blades to move towards the target angle.

[0037] In this step, the pitch controller controls the motor to rotate forward, driving the blades to retract from the current angle to the target angle. During this process, the controller acquires the blade angle information in real time through two independent sensors: one is a motor encoder mounted on the motor shaft, which has high resolution but is susceptible to cumulative error; the other is an absolute angle sensor mounted on the blade side or at the pitch bearing, which has high absolute accuracy but relatively low resolution.

[0038] Optionally, the two sensors can work in parallel, and the controller can perform integrated processing of the angle data from both sensors to ensure the accuracy and reliability of subsequent angle recordings.

[0039] In one alternative implementation, the target angle is 90°, which is the theoretical feathering angle, and the corresponding theoretical complementary position is 270°.

[0040] In another optional implementation, the target angle is set to 91°, which is the engineering feathering angle. Some units need to retract the blades to a position slightly greater than 90° due to the safety margin requirements of the blades and tower. The corresponding theoretical complementary position is 269°.

[0041] Step S202: When the blade enters the preset angle range centered on the target angle, record the forward angle detection value of the blade and control the pitch motor to rotate in the reverse direction. During the reverse stroke, obtain the reverse angle detection value of the blade at the theoretical complementary position. The angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle.

[0042] Specifically, step S202 above includes: Step S2021: Obtain the angle detection value of the blade. When the angle detection value enters the preset angle range centered on the target angle, record the current angle detection value as the positive angle detection value.

[0043] Taking a target angle of 90° as an example, when the forward feathering brings the blade angle close to 90°, the controller records the angle value θ read from the angle sensor at this time. fwd The preset angle range is an angle interval centered on the target angle with a deviation not exceeding ±0.5°.

[0044] Step S2022: Control the pitch motor to rotate in the reverse direction and monitor the angle detection value of the blade. When the angle detection value reaches the theoretical complementary position, record the current angle detection value as the reverse angle detection value. The angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle.

[0045] The angle value corresponding to the theoretical complementary position is 270°.

[0046] Taking a target angle of 90° as an example, according to the principle of full-range symmetrical mapping, since the single-rotation stroke of the pitch motor is a fixed 360°, if the forward 90° position is accurate, then when rotating in the opposite direction from that position, the corresponding position feature should be detectable at the complementary angle of 270°. The controller briefly reverses the motor's rotation, monitors whether the angle sensor reading is near 270° (allowable error range ±0.3°), outputs the expected signal or value, and records the reverse angle detection value θ at that position. rev .

[0047] The angle value corresponding to the theoretical complementary position is 270°.

[0048] For ease of understanding, see [link to relevant documentation]. Figure 3The diagram shows the pitch drive mechanism for wind turbine blades. The device adopts a dual-motor redundant drive scheme. The output power of the pitch motor 1 is transmitted through the gearbox 2 and then through the connecting structure 3 to drive the pinion 4 to rotate. The pinion 4 meshes with the large ring with internal teeth at the bottom. The large ring is connected to the wind turbine blades. The blades are driven to rotate by the transmission method of the pinion driving the large gear ring, thereby adjusting the windward angle of the blades.

[0049] Step S203: Based on the forward angle detection value and the reverse angle detection value, a comprehensive judgment is made. If the judgment condition is met, it is confirmed that the blade has reached the target position and the shutdown operation is performed. The judgment condition includes: the sum of the forward angle detection value and the reverse angle detection value is equal to the full range angle.

[0050] Specifically, taking a target angle of 90° as an example, the verification logic is as follows (to avoid contradictions between forward and reverse rotation, an allowable error band is defined): (1) If the forward angle detection value is within the preset angle range centered on the target angle and the reverse angle detection value is within the preset angle range centered on the theoretical complementary position, then it is determined that the blade has accurately reached the target position and the overstroke error has been eliminated; wherein, the forward angle detection value is the value read by the angle sensor when the forward feathering reaches the vicinity of the target angle, and the reverse angle detection value is the value read by the angle sensor when rotating in the opposite direction from that position to the vicinity of the theoretical complementary position.

[0051] For example, if the positive angle detection value θ fwd ≈90° and the reverse angle detection value θ during reverse verification rev If θ ≈ 270°, then the positive 90° position is accurate, and the overtravel error has been eliminated; where θ fwd θ is the value read by the angle sensor when the forward feathering reaches 90°. rev This is the value read by the angle sensor when rotating in the opposite direction from this position to the theoretical complementary position.

[0052] (2) When the sum of the forward angle detection value and the reverse angle detection value is not equal to the full-range angle and the deviation is within the preset deviation range, a systematic bias error is determined to exist, and the systematic bias error is corrected. The preset deviation range is 0.3° to 0.5°. This systematic bias error can be corrected by software compensation. The specific method is as follows: calculate the angle bias value based on the deviation of the sum of the forward angle detection value and the reverse angle detection value relative to the full-range angle, and store the bias value in the pitch controller parameter table. All subsequent angle readings will be automatically subtracted from the bias value, thereby eliminating the systematic bias error without any hardware disassembly and adjustment.

[0053] For example, if θ fwd +θ revWhen the deviation is θ = 360° ± ε (where ε is a small allowable measurement error, ranging from 0.3° to 0.5°), a systematic bias error is considered to exist. This bias error can be corrected through software compensation by calculating the bias value θ. offset =(θ fwd +θ rev -360°) / 2, and store this offset value in the pitch controller parameter table. All subsequent angle readings will be automatically subtracted by θ. offset This eliminates systematic bias errors without any hardware disassembly or adjustment. This implementation eliminates systematic bias errors through software compensation, requiring no hardware disassembly or mechanical adjustment of the limit switch, significantly reducing on-site maintenance and time costs.

[0054] It should be noted that this verification logic applies not only to the case where the angle detection value falls within the preset angle range centered on the target angle, as described in the above scheme, but also to scenarios where the propeller blade fails to fall within the preset angle range due to factors such as overtravel. For example, the propeller blade stops at 91° in the forward direction, i.e., θ. fwd The deviation from 90° by approximately 1° exceeds the preset angle range (±0.5°). At this point, if θ fwd +θ rev =360°±ε (e.g., 91°+269°=360°), which indicates that the measurement system has a fixed systematic bias, causing θ to... fwd The offset is always 1° greater than the actual angle. The offset value θ is calculated using the software compensation method described above. offset =1°. After storing this offset value in the controller parameter table, subsequent angle readings will be automatically reduced by 1°, and the actual position of the blade can be corrected to 90°, thereby achieving accurate compensation for overstroke error.

[0055] (3) If the sum of the forward angle detection value and the reverse angle detection value deviates from the full range angle beyond the preset deviation range, it is determined that there is encoder slippage or angle sensor failure, and an alarm is triggered.

[0056] For example, if θ fwd +θ rev If the deviation is not equal to 360° and exceeds the preset deviation range, it is determined that there is encoder slippage or angle sensor failure, and an alarm is triggered.

[0057] In one optional implementation, after the alarm is triggered, the controller controls the motor to continuously track and adjust at a first speed approaching the target angle and a second speed in the reverse convergence phase, wherein the second speed is lower than the first speed. After the adjustment is completed, the verification logic (1) is re-entered until the positive 90° position is accurate, then the stop brake operation is performed.

[0058] The wind turbine pitch positioning method provided in this embodiment introduces a bidirectional cross-verification mechanism with full-range symmetrical angle mapping. Utilizing the fixed full-range characteristic of the pitch motor's 360° rotation, the target angle reached by forward feathering is mapped to the theoretical complementary angle during reverse rotation. By verifying whether the sum of the angle detection values ​​in both directions equals 360°, bidirectional redundancy verification of the blade's stopping position is achieved. This embodiment overcomes the limitation of traditional schemes that only compensate for forward inertial overshoot in a unidirectional manner. By cross-verifying forward and reverse angles, it simultaneously eliminates errors in both forward overtravel and reverse tolerance, achieving bidirectional symmetrical compensation. This improves the feathering positioning accuracy from ±0.5°~±1° in traditional schemes to within ±0.1°. Furthermore, the introduction of forward and reverse angle sensor readings as two independent information sources for cross-verification effectively avoids the single-point failure risk associated with a single limit switch signal source, significantly improving the reliability of pitch positioning. Furthermore, this embodiment also achieves accurate identification and software correction of systematic bias errors by detecting the deviation of the sum of the positive and negative angles relative to the full-range angle. Systematic deviations can be eliminated without any hardware disassembly or mechanical adjustment, reducing on-site maintenance costs. At the same time, by setting a deviation threshold, effective monitoring of encoder slippage or angle sensor failure is achieved, further improving the safety and reliability of the system.

[0059] This embodiment provides yet another method for wind turbine pitch positioning. Figure 4 This is a flowchart of a wind turbine pitch positioning method according to an embodiment of the present invention, such as... Figure 4 As shown, the process includes the following steps: Step S401: Control the pitch motor to rotate forward, driving the blades to move towards the target angle. For details, please refer to [link to relevant documentation]. Figure 2 Step S201 of the illustrated embodiment will not be described again here.

[0060] Step S402: When the blade enters a preset angle range centered on the target angle, record the forward angle detection value of the blade and control the pitch motor to rotate in the reverse direction. During the reverse stroke, obtain the reverse angle detection value of the blade at the theoretical complementary position; wherein, the angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle. For details, please refer to [link to details]. Figure 2 Step S202 of the illustrated embodiment will not be described again here.

[0061] Step S403: Obtain the electrical operating parameters of the pitch motor.

[0062] Electrical operating parameters include the torque command value of the pitch motor and / or the output current value of the driver. As the blades approach the target position of 90°, the controller acquires the above electrical operating parameters in real time through the driver for subsequent verification of electrical auxiliary criteria.

[0063] The physical basis for this is that, according to the aerodynamic principles of wind power generation, the aerodynamic load on the blades decreases as the blade angle β increases, reaching a minimum value at β=90° (fully feathered position), approaching zero. Therefore, when the blade angle is close to 90°, the aerodynamic load decreases, and the torque and drive current required by the motor to overcome the aerodynamic load should be significantly reduced.

[0064] Step S404: Based on the forward angle detection value, the reverse angle detection value, and the electrical operating parameters, a comprehensive judgment is made. When the judgment conditions are met, it is confirmed that the blade has reached the target position and a shutdown operation is performed. The judgment conditions include: the sum of the forward angle detection value and the reverse angle detection value is equal to the full range angle, and during the blade's movement toward the target angle, the electrical operating parameters show a monotonically decreasing trend and are lower than the preset electrical threshold at the target angle.

[0065] In this step, the controller simultaneously uses the forward angle detection value, the reverse angle detection value, and electrical operating parameters to make a comprehensive judgment: Criterion 1 (Positive Angle Criterion): Based on the positive angle detection value θ obtained by the angle sensor. fwd To determine whether it is near the target angle, specifically θ fwd ∈[89.5°, 90.5°]. It should be noted that the pass condition of this criterion is the same as... Figure 2 In step S2021 of the illustrated embodiment, the preset angle range for triggering the recording of the forward angle detection value is consistent. This condition has already been pre-screened in step S2021, and it can be reconfirmed in the comprehensive judgment stage to ensure that θ is consistent with the subsequent angle verification and electrical criteria. fwd Always meet the positive angle requirement to avoid misjudgment due to signal jitter or recording timing deviation.

[0066] Criterion 2 (Reverse Verification Criterion): Based on the full-range angle symmetry mapping, determine whether the sum of the forward angle detection value and the reverse angle detection value equals the full-range angle, specifically θ. fwd +θ rev =360°±0.5°. See details. Figure 2 Step S203 of the illustrated embodiment will not be described here.

[0067] Criterion 3 (Torque / Current Criterion): Based on the electrical operating parameters fed back by the driver, determine whether the electrical operating parameters show a monotonically decreasing trend as the blade moves toward the target angle, and whether the final electrical operating parameters are less than or equal to the preset electrical threshold.

[0068] Specifically, when the blade angle is within the range of 85° to 90°, the motor torque command value T is monitored. cmd and actual current I act If T cmd and Iact It exhibits a monotonically decreasing trend as the angle approaches 90°, and eventually T cmd Less than the preset threshold T th (e.g., 10% of the rated torque) then verifies from an electrical perspective that the blade is indeed in a low-load position close to 90°. Combined with the results of the angle verification, it is confirmed that the blade has reached the target position and the shutdown operation is performed.

[0069] If the electrical operating parameters do not show a monotonically decreasing trend or do not fall below the preset electrical threshold at the target angle during the blade's movement towards the target angle, then mechanical jamming is determined to exist, triggering an alarm. If T cmd If the brake pads do not descend or even rise, it indicates that there may be mechanical jamming or abnormal angle sensor readings. This can easily cause brake pad wear and overtravel problems, and the controller will trigger an alarm to remind maintenance personnel to investigate and handle the problem in a timely manner.

[0070] After all three criteria are met, the controller confirms that the blades have accurately reached the target feathering position before executing the stop brake. If any criterion fails, the controller does not execute the stop brake and instead performs the corresponding exception handling logic based on the type of the failed criterion: if criterion one fails, it indicates that the actual blade position deviates from the target angle, and the controller continues to perform angle adjustment; if criterion two fails, it indicates that the angle verification has failed, which may indicate a sensor malfunction or encoder slippage, triggering an alarm; if criterion three fails, it indicates an abnormal electrical parameter, which may indicate mechanical jamming, triggering an alarm. By comprehensively determining the position using the AND logic of three independent criteria, a redundant safety design for position confirmation is achieved, effectively avoiding the risk of misjudgment caused by the failure of a single signal source, and further improving the safety and reliability of the pitch positioning system.

[0071] The core physical mechanism of the wind turbine pitch positioning method provided in this embodiment lies in the fact that the single-cycle stroke of the pitch motor is a fixed full-range angle. Utilizing this inherent characteristic, the target angle for forward feathering is mapped to a complementary angle in the opposite direction. Overtravel error is determined and eliminated by verifying whether the sum of the forward and reverse angles equals the full-range angle. Traditional overtravel errors arise from factors such as mechanical tolerances, control delays, and inertia, resulting in an actual stopping position greater than the target angle (e.g., 91°~93°). The solution proposed in this invention is as follows: First, real-time monitoring of the forward angle. This invention does not rely on a single limit switch edge signal to trigger a stop. Instead, it continuously reads the blade angle value through an angle sensor during feathering. When the blade enters a preset angle range near the target angle, the forward angle detection value is recorded. This fundamentally avoids the problem that a single switch signal is easily interfered with by factors such as mechanical vibration and response delay.

[0072] Second, reverse angle mapping verification. This invention utilizes the geometric constraints of the full-range angle of a single revolution of the pitch motor. After the blade reaches the vicinity of the target angle, the motor is controlled to rotate in the opposite direction to the theoretical complementary position to obtain the reverse angle detection value. By verifying whether the sum of the forward angle detection value and the reverse angle detection value is equal to the full-range angle, independent cross-verification of the blade docking position is achieved, effectively avoiding the risk of single-point failure caused by a single signal source.

[0073] Third, electrical parameters are used for auxiliary verification. This invention further utilizes the physical characteristic of minimal aerodynamic load at the 90° position to verify position accuracy through the decreasing trend of torque / current. According to the aerodynamic principles of wind power generation, the aerodynamic torque coefficient of the blade decreases as the blade angle increases, reaching a minimum value close to zero at the fully feathered position. When the blade angle changes from 85° to 90°, the aerodynamic load exhibits a monotonically decreasing trend, and the torque output required by the motor to overcome the aerodynamic load also decreases monotonically, resulting in a corresponding decrease in the driver output current. This invention uses the changing trend of motor torque / current as an auxiliary verification criterion for blade position accuracy. If, during the change of blade angle from 85° to 90°, the torque / current exhibits the expected monotonically decreasing trend, and the final value is lower than a preset threshold (such as 10% of the rated torque), then it independently verifies from an electrical perspective that the blade is indeed in a low-load position close to 90°, enhancing the reliability of position confirmation.

[0074] Fourth, software compensation. When a systematic offset error is detected, angle offset compensation parameters can be set in the controller, eliminating the offset error without adjusting the hardware installation position, significantly reducing on-site maintenance costs.

[0075] In summary, by adopting the method of this invention, the accuracy of feathering positioning is improved from ±0.5°~±1° in the traditional scheme to within ±0.1°; the dependence on the 91° overstroke margin is eliminated, and the limit switch can be accurately installed at the theoretical 90° position; at the same time, three independent information sources (forward angle, reverse mapping, and torque current) are provided, and any abnormality of any criterion can trigger an alarm, realizing a redundant safety design for position confirmation.

[0076] Taking a pitch control system of a 3.0MW wind turbine generator as an example, the application effect of the method of the present invention is verified.

[0077] The unit originally used a 91° limit switch as the feathering position signal. However, in actual operation, due to factors such as mechanical tolerances, control precision, motor inertia, and signal response delay, the actual blade stopping position statistics show an average of 91.6°, a standard deviation of 0.4°, and a maximum overshoot of 92.3°. This large overshoot raises concerns about insufficient safety margin between the blades and the tower.

[0078] The pitch system of this unit was modified using the method of this invention, and the following functional modules were added to the pitch controller: reading the angle data of the motor encoder and the absolute angle sensor on the blade side; adding a reverse rotation verification subroutine, which automatically performs a reverse micro-motion verification after each feathering operation; and adding torque / current monitoring and recording functions.

[0079] The results of the modification are as follows: the average heeling position was 90.1°, the standard deviation was 0.08°, and the maximum deviation was 90.3°, indicating a significant improvement in heeling accuracy compared to before the modification; in reverse verification, θ fwd +θ rev =360.05°±0.15°, which meets the theoretical expectation of full-range symmetrical angular mapping; in terms of torque monitoring, when approaching 90°, the torque command drops from 15% of the rated torque to 3% of the rated torque, which verifies from an electrical perspective that the blade is indeed in a low-load position, and is consistent with the angle verification results.

[0080] The above implementation results show that, by adopting the method of the present invention, the dependence on the 91° overstroke margin is eliminated, the limit switch can be adjusted to the accurate 90° position, and the feathering positioning accuracy and system operation reliability are improved while eliminating overstroke error, thus verifying the effectiveness and engineering applicability of the method of the present invention.

[0081] This embodiment also provides a wind turbine pitch positioning device, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementations, or a combination of software and hardware, are also possible and contemplated.

[0082] This embodiment provides a wind turbine pitch positioning device, such as... Figure 5 As shown, it includes: The blade motion module 501 is used to control the pitch motor to rotate in the forward direction and drive the blades to move towards the target angle. Angle detection module 502 is used to record the forward angle detection value of the blade when the blade enters a preset angle range centered on the target angle, and control the pitch motor to rotate in the reverse direction to obtain the reverse angle detection value of the blade at the theoretical complementary position during the reverse stroke; wherein, the angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle. The position determination module 503 is used to make a comprehensive determination based on the forward angle detection value and the reverse angle detection value. When the determination conditions are met, it is confirmed that the blade has reached the target position and the shutdown operation is performed. The determination conditions include: the sum of the forward angle detection value and the reverse angle detection value is equal to the full range angle.

[0083] In some alternative implementations, the angle detection module 502 includes: The forward recording unit is used to acquire the angle detection value of the blade. When the angle detection value enters the preset angle range centered on the target angle, the current angle detection value is recorded as the forward angle detection value.

[0084] The reverse recording unit is used to control the pitch motor to rotate in the reverse direction and monitor the angle detection value of the blade. When the angle detection value reaches the theoretical complementary position, the current angle detection value is recorded as the reverse angle detection value. The angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle.

[0085] In some optional embodiments, an electrical operating parameter acquisition module is included before the position determination module 503 to acquire the electrical operating parameters of the pitch motor. In this embodiment, the position determination module 503 is used to make a comprehensive determination based on the forward angle detection value, the reverse angle detection value, and the electrical operating parameters. When the determination conditions are met, it is confirmed that the blade has reached the target position and a shutdown operation is performed. The determination conditions include: the sum of the forward angle detection value and the reverse angle detection value is equal to the full-range angle, and during the movement of the blade towards the target angle, the electrical operating parameters show a monotonically decreasing trend and are lower than a preset electrical threshold at the target angle.

[0086] The wind turbine pitch positioning device provided in this embodiment of the invention can execute the wind turbine pitch positioning method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the various modules and units described above are the same as in the corresponding embodiments described above, and will not be repeated here.

[0087] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0088] The following is a detailed reference. Figure 6 This diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 601, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 602 or a program loaded from memory 608 into random access memory (RAM) 603. RAM 603 also stores various programs and data required for the operation of the electronic device. The processor 601, ROM 602, and RAM 603 are interconnected via bus 604. Input / output (I / O) interface 605 is also connected to bus 604.

[0089] Typically, the following devices can be connected to I / O interface 605: input devices 606 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 607 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 608 including, for example, magnetic tapes, hard disks, etc.; and communication devices 609. Communication device 609 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 6 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0090] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 609, or installed from a memory 608, or installed from a ROM 602. When the computer program is executed by the processor 601, it performs the functions defined in the wind turbine pitch positioning method of the embodiments of the present invention.

[0091] Figure 6 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0092] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the wind turbine pitch positioning method shown in the above embodiments is implemented.

[0093] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0094] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A wind turbine pitch control positioning method, characterized in that, The method includes: Control the pitch motor to rotate in the forward direction, driving the blades to move towards the target angle; When the blade enters a preset angle range centered on the target angle, the forward angle detection value of the blade is recorded, and the pitch motor is controlled to rotate in the reverse direction. During the reverse stroke, the reverse angle detection value of the blade at the theoretical complementary position is obtained; wherein, the angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle. Based on the combined judgment of the forward angle detection value and the reverse angle detection value, when the judgment condition is met, it is confirmed that the blade has reached the target position and a shutdown operation is performed; the judgment condition includes: the sum of the forward angle detection value and the reverse angle detection value is equal to the full range angle.

2. The wind turbine pitch positioning method according to claim 1, characterized in that, The target angle is 90°, and the angle corresponding to the theoretical complementary position is 270°.

3. The wind turbine pitch positioning method according to claim 1, characterized in that, The preset angle range is an angle interval centered on the target angle with a deviation not exceeding ±0.5°.

4. The wind turbine pitch control positioning method according to claim 1, characterized in that, When the sum of the forward angle detection value and the reverse angle detection value is not equal to the full-range angle and the deviation is within the preset deviation range, it is determined that there is a systematic bias error, and the systematic bias error is corrected.

5. The wind turbine pitch positioning method according to claim 4, characterized in that, The preset deviation range is 0.3° to 0.5°.

6. The wind turbine pitch positioning method according to claim 1, characterized in that, If the sum of the forward angle detection value and the reverse angle detection value deviates from the full-range angle by more than a preset deviation range, it is determined that there is encoder slippage or angle sensor malfunction, and an alarm is triggered.

7. The wind turbine pitch positioning method according to claim 1, characterized in that, Also includes: Obtain the electrical operating parameters of the pitch motor; The determination criteria also include: during the movement of the blade toward the target angle, the electrical operating parameters show a monotonically decreasing trend and are below a preset electrical threshold at the target angle.

8. The wind turbine pitch positioning method according to claim 7, characterized in that, If the electrical operating parameters do not show a monotonically decreasing trend or do not fall below a preset electrical threshold at the target angle during the movement of the blade toward the target angle, it is determined that there is mechanical jamming, and an alarm is triggered.

9. A wind turbine pitch positioning device, characterized in that, The device includes: The blade motion module is used to control the forward rotation of the pitch motor, driving the blades to move towards the target angle; An angle detection module is used to record the forward angle detection value of the blade when the blade enters a preset angle range centered on the target angle, and control the pitch motor to rotate in the reverse direction to obtain the reverse angle detection value of the blade at the theoretical complementary position during the reverse stroke; wherein, the angle value corresponding to the theoretical complementary position is the full-range angle minus the target angle; The position determination module is used to make a comprehensive determination based on the forward angle detection value and the reverse angle detection value. When the determination condition is met, it is confirmed that the blade has reached the target position and a shutdown operation is performed. The determination condition includes: the sum of the forward angle detection value and the reverse angle detection value is equal to the full-range angle.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the wind turbine pitch positioning method according to any one of claims 1 to 8.

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