Wind turbine main drive corner rotation speed detection system and detection method

Abstract

The application discloses a kind of wind turbine main drive corner rotational speed detection system and detection method, the system includes: two proximity switches, two proximity switches are fixedly installed on the bearing seat of wind turbine main shaft, the detection end of two proximity switches is directed to main shaft bearing, and the exposed screw rod portion of the compression ring bolt of main shaft bearing can trigger the action of proximity switch;Metal detection body, metal detection body is installed between any two compression ring bolts, metal detection body can rotate along with wind turbine main drive system, and metal detection body can trigger the action of proximity switch;Control module, control module is connected with proximity switch, for collecting and calculating the angle of rotation and rotational speed of wind turbine main drive system according to the detection signal of two proximity switches.The application detects the compression ring bolt of main shaft bearing by using two proximity switches, and sets a metal detection body as calibration point, can realize the detection measurement of main drive angle and rotational speed, measurement cost is low, and measurement precision is high.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and in particular to a system and method for detecting the main drive rotation angle and speed of a wind turbine. Background Technology

[0002] Wind energy is an inexhaustible and clean energy source. Wind turbines convert wind energy into mechanical energy through rotor rotation, and then convert that mechanical energy into electrical energy through a power generation system. To monitor and control the operation of wind turbines, it is necessary to collect the rotational speed of the main drive system (i.e., the rotor speed) in real time. This allows for advanced control such as independent pitch control. Additionally, under certain special operating conditions, it is also necessary to collect the rotational angle of the main drive system. In existing methods for measuring the rotational speed and angle of the main drive system, for models without a speed-increasing gearbox, the generator's photoelectric encoder is used directly to detect the speed and angle. For models with a speed-increasing gearbox, the high-speed end uses the generator's photoelectric encoder to detect the speed and angle, or a proximity switch is used to measure the signal pulse changes on the indexing dial to calculate the speed. The low-speed end uses a proximity switch to measure the signal pulse changes on the indexing dial to calculate the speed.

[0003] However, while using photoelectric encoders to detect the speed and angle of the wind turbine's main drive system offers high measurement accuracy, the high precision requirements and inconvenient installation, coupled with a high failure rate in practical use, result in poor economic efficiency. While a single proximity switch can meet the speed measurement needs of the wind turbine's main drive system, it requires an additional indexing plate, resulting in lower actual measurement accuracy and the inability to detect the rotation angle of the main drive system. Summary of the Invention

[0004] To address some or all of the technical problems existing in the prior art, the present invention provides a wind turbine main drive rotation angle and speed detection system and method.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect, a wind turbine main drive rotation angle and speed detection system is provided, the system comprising:

[0007] Two proximity switches are fixedly mounted on the bearing housing of the main shaft of the wind turbine. The detection ends of the two proximity switches point to the main shaft bearing, and the exposed screw portion of the clamping ring bolt of the main shaft bearing can trigger the proximity switch to operate.

[0008] A metal detector is installed between any two of the clamping ring bolts. The metal detector can rotate with the main drive system of the wind turbine and can trigger the proximity switch.

[0009] A control module, connected to the proximity switches, is used to collect and calculate the rotation angle and speed of the main drive system of the wind turbine based on the detection signals from the two proximity switches.

[0010] In some possible implementations, the proximity switch is fixedly mounted on the rear end of the bearing housing via a bracket.

[0011] In some possible implementations, the installation distance between the two proximity switches is greater than the sum of the screw spacing and screw diameter of the two adjacent bolts, less than the sum of the screw spacing and twice the screw diameter of the two adjacent bolts, and less than the sum of the screw diameter and twice the screw spacing of the two adjacent bolts.

[0012] In some possible implementations, the proximity switch outputs a high-level signal when it detects the screw and the metal detector, and a low-level signal at other times.

[0013] Secondly, a method for detecting the main drive angle and speed of a wind turbine generator using the aforementioned wind turbine main drive angle and speed detection system is also provided, the method comprising:

[0014] When the first proximity switch or the second proximity switch detects a metal detector, the main drive system rotates clockwise by a first relative angle relative to a preset initial position.

[0015] During the rotation of the main drive system, the rotation angle of the main drive system is calculated based on the detection signals output by the two proximity switches. When the main drive system rotates to the position corresponding to the first relative rotation angle, the accumulated rotation angle is set to zero, and the rotation angle of the main drive system is recalculated based on the detection signals output by the two proximity switches starting from zero.

[0016] Based on the first relative rotation angle and the calculated rotation angle, calculate the rotation angle of the main drive system relative to the preset initial position;

[0017] The rotational speed of the main drive system is calculated based on the rotational angle of the main drive system relative to the preset initial position.

[0018] In some possible implementations, a GL fixed hub coordinate system is established with the hub center of the wind turbine as the origin. The initial position is when the Z-axis of the GL fixed hub coordinate system coincides with the axis of a specified blade, and the rotation angle of the main drive system at the initial position is set to 0°.

[0019] In some possible implementations, the proximity switch is configured to output a high-level signal when it detects the screw and the metal detector, and a low-level signal at other times. Then, based on the detection signals output by the two proximity switches, the rotation angle of the main drive system is calculated using the following formula:

[0020]

[0021] Where Q represents the rotation angle of the main drive system, n represents the total number of bolts around the bearing clamping ring, K represents the bolt diameter, M is the distance between the bolts of two adjacent bolts, N represents the installation distance between the two proximity switches, K+M<N<2K+M and K+M<N<K+2M, a, b, c, and d represent the number of LL-line pulse signals, HL-line pulse signals, HH-line pulse signals, and LH-line pulse signals collected by the first and second proximity switches when the main drive system rotates in one direction, respectively, where L represents low level and H represents high level.

[0022] In some possible implementations, when calculating the rotation angle of the main drive system relative to the preset initial position, the rotation direction of the main drive system is also determined based on the cyclic sequence of the pulse signals collected by the first proximity switch and the second proximity switch.

[0023] In some possible implementations, when the main drive system rotates clockwise, the rotation angle of the main drive system relative to a preset initial position is calculated using the following formula:

[0024] θ = (Q + W) mod (360°)

[0025] When the main drive system rotates counterclockwise, the rotation angle of the main drive system relative to the preset initial position is calculated using the following formula:

[0026] θ = (360° - Q + W) mod (360°)

[0027] Wherein, θ represents the rotation angle of the main drive system relative to the preset initial position, Q represents the rotation angle of the main drive system calculated based on the detection signals output by the two proximity switches, and W represents the first relative rotation angle.

[0028] In some possible implementations, the rotational speed of the main drive system is calculated using the following formula:

[0029]

[0030] Where ω represents the rotational speed of the main drive system, θ represents the rotational angle of the main drive system relative to the preset initial position, and t represents time.

[0031] The main advantages of the technical solution of this invention are as follows:

[0032] The wind turbine main drive angle and speed detection system and method of the present invention utilizes two proximity switches to detect the main shaft bearing clamping ring bolts. Based on the detection signals of the two proximity switches, a specific algorithm can be used to detect and measure the angle and speed of the main drive, resulting in low measurement cost. At the same time, a metal detector is installed between any two clamping ring bolts as a calibration point to complete the zeroing calibration of the angle after each revolution of the main drive system, which can avoid the influence of the cumulative calculation error of the angle and further improve the measurement accuracy of the angle and speed. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and constitute a part of this invention, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0034] Figure 1 This is a schematic diagram of a wind turbine main drive rotation angle and speed detection system according to an embodiment of the present invention, wherein the metal detection body is not shown;

[0035] Figure 2 This is a schematic diagram of the installation position of a proximity switch according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the installation position of the proximity switch from another perspective of an embodiment of the present invention;

[0037] Figure 4 This is a flowchart of a wind turbine main drive rotation angle and speed detection method according to an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of a GL fixed hub coordinate system established according to an embodiment of the present invention;

[0039] Figure 6 This is a schematic diagram of the high and low level signal sequence output by the proximity switch when detecting the screw according to an embodiment of the present invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1-First proximity switch, 2-Second proximity switch, 3-Bearing housing, 4-Pressure ring bolt, 5-Bracket. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] refer to Figure 1-3 An embodiment of the present invention provides a wind turbine main drive rotation angle and speed detection system, the system comprising:

[0045] Two proximity switches are fixedly installed on the bearing housing 3 of the main shaft of the wind turbine. The detection ends of the two proximity switches point to the main shaft bearing, and the exposed screw part of the clamping ring bolt 4 of the main shaft bearing can trigger the proximity switch to act.

[0046] The metal detector is installed between any two clamping ring bolts 4. The metal detector can rotate with the main drive system of the wind turbine and can trigger the proximity switch.

[0047] The control module is connected to the proximity switches and is used to collect and calculate the rotation angle and speed of the main drive system of the wind turbine based on the detection signals from the two proximity switches.

[0048] Specifically, in one embodiment of the present invention, the wind turbine main drive rotation angle and speed detection system, when used for detecting the rotation angle and speed of the wind turbine main drive, first determines the first relative rotation angle of the main drive system relative to the preset initial position in a clockwise direction when the first proximity switch 1 or the second proximity switch 2 detects a metal detector. Then, during the rotation of the main drive system, the control module calculates the rotation angle of the main drive system based on the detection signals output by the two proximity switches. Simultaneously, since the first proximity switch 1 and the second proximity switch 2 can detect a metal detector once for each rotation of the main drive system, when the main drive system rotates to the position corresponding to the first relative rotation angle, the control module sets the previously accumulated rotation angle to zero, and in subsequent rotations of the main drive system, recalculates the rotation angle of the main drive system from zero based on the detection signals output by the two proximity switches to avoid the continuous accumulation of calculation errors. Then, based on the previously determined first relative rotation angle and the calculated rotation angle of the main drive system, the rotation angle of the main drive system relative to the preset initial position is calculated and determined. Finally, the speed of the main drive system is calculated and determined based on the rotation angle of the main drive system relative to the preset initial position.

[0049] refer to Figure 2-3 In one embodiment of the present invention, the proximity switches are fixedly mounted on the rear end of the bearing housing 3 via a bracket 5. That is, two proximity switches are mounted on the bracket 5, and the bracket 5 with the proximity switches is mounted on the rear end face of the bearing housing 3.

[0050] Furthermore, in one embodiment of the present invention, in order to facilitate the measurement of the rotational speed of the main drive system and to ensure measurement accuracy, the installation distance between the two proximity switches is greater than the sum of the screw spacing and screw diameter of two adjacent bolts, less than the sum of the screw spacing and twice the screw diameter of two adjacent bolts, and less than the sum of the screw diameter and twice the screw spacing of two adjacent bolts.

[0051] Specifically, let K represent the diameter of the bolt thread, M be the distance between the threads of two adjacent bolts, and N be the installation distance between two proximity switches. Then N needs to satisfy the condition: K+M<N<2K+M and K+M<N<K+2M.

[0052] Furthermore, in one embodiment of the present invention, a normally closed signal feedback proximity switch is used. When the proximity switch detects the screw and the metal detector, the proximity switch outputs a high-level signal, and at other times it outputs a low-level signal.

[0053] Furthermore, in one embodiment of the present invention, the control module may be a programmable logic controller (PLC).

[0054] refer to Figure 4 An embodiment of the present invention also provides a method for detecting the main drive angle and speed of a wind turbine generator set. This method is implemented using the aforementioned wind turbine generator set main drive angle and speed detection system and includes the following steps:

[0055] Step S100: Determine the first relative rotation angle of the main drive system relative to the preset initial position in a clockwise direction when the first proximity switch or the second proximity switch detects a metal detector.

[0056] refer to Figure 5 In one embodiment of the present invention, a GL fixed hub coordinate system is established with the hub center of the wind turbine as the origin. The origin of the GL fixed hub coordinate system is the hub center of the wind turbine. The X-axis points to the main shaft and coincides with the axis of the main shaft. The Z-axis is perpendicular to the ground and upward. The Y-axis is perpendicular to the plane formed by the X-axis and Z-axis and forms a right-hand rectangular coordinate system with the X-axis and Z-axis.

[0057] Furthermore, the initial position is set when the Z-axis of the GL fixed hub coordinate system coincides with the axis of a specified blade, and the rotation angle of the main drive system at the initial position is set to 0°.

[0058] refer to Figure 6Since the clamping ring bolts 4 are uniformly distributed along the circumference of the clamping ring, if no metal detector is provided, each pulse signal detected by the same proximity switch will have the same period, including a high-level signal and a low-level signal. Therefore, in one embodiment of the present invention, if two adjacent pulse signal periods detected by the same proximity switch are significantly different, it is considered that the proximity switch has detected a metal detector.

[0059] Step S200: During the rotation of the main drive system, the rotation angle of the main drive system is calculated based on the detection signals output by the two proximity switches.

[0060] refer to Figure 6 In one embodiment of the present invention, the proximity switches are configured to use normally closed signal feedback, that is, the proximity switches output a high-level signal when they detect the screw and the metal detection body, and output a low-level signal at other times. Then, based on the detection signals output by the two proximity switches, the rotation angle of the main drive system is calculated using the following formula:

[0061]

[0062] Where Q represents the rotation angle of the main drive system, n represents the total number of bolts around the bearing clamping ring, K represents the bolt diameter, M is the distance between the bolts of two adjacent bolts, N represents the installation distance between the two proximity switches, K+M<N<2K+M and K+M<N<K+2M, a, b, c, and d represent the number of LL-line pulse signals, HL-line pulse signals, HH-line pulse signals, and LH-line pulse signals collected by the first and second proximity switches when the main drive system rotates in one direction, respectively, where L represents low level and H represents high level.

[0063] Correspondingly, when the proximity switch adopts the normally open signal feedback form, that is, the proximity switch outputs a low-level signal when it detects the screw and the metal detection body, and outputs a high-level signal at other times, the corresponding parameters can be modified according to the above calculation formula to determine the calculation formula for the rotation angle of the corresponding main drive system.

[0064] Furthermore, since both the first proximity switch 1 and the second proximity switch 2 can detect a metal object once for each revolution of the main drive system, in one embodiment of the present invention, when the main drive system rotates to the position corresponding to the first relative rotation angle, the previously accumulated rotation angle is set to zero. During subsequent rotations of the main drive system, the rotation angle is recalculated from zero based on the detection signals output by the two proximity switches, thus avoiding the continuous accumulation of calculation errors and improving the accuracy of the rotation angle and speed measurement of the main drive system.

[0065] Step S300: Calculate the rotation angle of the main drive system relative to the preset initial position based on the first relative rotation angle and the calculated rotation angle;

[0066] In practical applications, the main drive system may rotate clockwise or counterclockwise. To ensure accurate calculation of the rotation angle of the main drive system, it is also necessary to determine the rotation direction of the main drive system when calculating the rotation angle of the main drive system relative to the preset initial position.

[0067] In one embodiment of the present invention, the rotation direction of the main drive system is determined based on the cyclic sequence of the pulse signals collected by the first proximity switch 1 and the second proximity switch 2.

[0068] Specifically, refer to Figure 3 and Figure 6 When the first proximity switch 1 and the second proximity switch 2 are sequentially distributed clockwise, if the pulse signal cycles in the order LL, HL, HH, LH, the main drive system rotates clockwise; if the pulse signal cycles in the order LH, HH, HL, LL, the main drive system rotates counterclockwise. Conversely, when the first proximity switch 1 and the second proximity switch 2 are sequentially distributed counterclockwise, if the pulse signal cycles in the order LH, HH, HL, LL, the main drive system rotates clockwise; if the pulse signal cycles in the order LL, HL, HH, LH, the main drive system rotates counterclockwise. Figure 3 In the middle, the first proximity switch 1 and the second proximity switch 2 are distributed in a clockwise direction.

[0069] Furthermore, in one embodiment of the present invention, when the main drive system rotates clockwise, the rotation angle of the main drive system relative to the preset initial position is calculated using the following formula:

[0070] θ = (Q + w) mod (360°)

[0071] When the main drive system rotates counterclockwise, the rotation angle of the main drive system relative to the preset initial position is calculated using the following formula:

[0072] θ = (360° - Q + W) mod (360°)

[0073] Where θ represents the rotation angle of the main drive system relative to the preset initial position, Q represents the rotation angle of the main drive system calculated based on the detection signals output by the two proximity switches, and W represents the first relative rotation angle.

[0074] Step S400: Calculate the rotational speed of the main drive system based on the rotational angle of the main drive system relative to the preset initial position.

[0075] In one embodiment of the present invention, the rotational speed of the main drive system is calculated using the following formula:

[0076]

[0077] Where ω represents the rotational speed of the main drive system, θ represents the rotational angle of the main drive system relative to the preset initial position, and t represents time.

[0078] By taking the derivative of the rotation angle of the main drive system, the corresponding rotational speed of the main drive system can be determined.

[0079] An embodiment of the present invention provides a wind turbine main drive angle and speed detection system and method that utilizes two proximity switches to detect the main shaft bearing clamping ring bolts. Based on the detection signals from the two proximity switches, a specific algorithm can be used to detect and measure the angle and speed of the main drive, resulting in low measurement costs. Simultaneously, a metal detector is installed between any two clamping ring bolts as a calibration point to perform zeroing calibration of the angle after each revolution of the main drive system. This avoids the influence of cumulative angle calculation errors and further improves the measurement accuracy of the angle and speed.

[0080] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Additionally, the terms "front," "back," "left," "right," "upper," and "lower" in this document refer to the placement shown in the accompanying drawings.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wind turbine main drive rotation angle and speed detection system, characterized in that, include: Two proximity switches are fixedly mounted on the bearing housing of the main shaft of the wind turbine. The detection ends of the two proximity switches point to the main shaft bearing, and the exposed screw portion of the clamping ring bolt of the main shaft bearing can trigger the proximity switch to operate. A metal detector is installed between any two of the clamping ring bolts. The metal detector can rotate with the main drive system of the wind turbine and can trigger the proximity switch. A control module, connected to the proximity switches, is used to collect and calculate the rotation angle and speed of the main drive system of the wind turbine based on the detection signals of the two proximity switches; The metal detector serves as a calibration point to complete the zeroing calibration of the rotation angle after each revolution of the main drive system of the wind turbine. When the proximity switch detects the screw and the metal detector, the proximity switch outputs a high-level signal; otherwise, it outputs a low-level signal.

2. The wind turbine main drive rotation angle and speed detection system according to claim 1, characterized in that, The proximity switch is fixedly mounted on the rear end of the bearing housing via a bracket.

3. The wind turbine main drive rotation angle and speed detection system according to claim 1, characterized in that, The installation distance between the two proximity switches is greater than the sum of the screw spacing and screw diameter of the two adjacent bolts, less than the sum of the screw spacing and twice the screw diameter of the two adjacent bolts, and less than the sum of the screw diameter and twice the screw spacing of the two adjacent bolts.

4. A method for detecting the main drive angle and speed of a wind turbine generator using the wind turbine main drive angle and speed detection system as described in any one of claims 1-3, characterized in that, include: When the first proximity switch or the second proximity switch detects a metal detector, the main drive system rotates clockwise by a first relative angle relative to a preset initial position. During the rotation of the main drive system, the rotation angle of the main drive system is calculated based on the detection signals output by the two proximity switches. When the main drive system rotates to the position corresponding to the first relative rotation angle, the accumulated rotation angle is set to zero, and the rotation angle of the main drive system is recalculated based on the detection signals output by the two proximity switches starting from zero. Based on the first relative rotation angle and the calculated rotation angle, calculate the rotation angle of the main drive system relative to the preset initial position; The rotational speed of the main drive system is calculated based on the rotational angle of the main drive system relative to the preset initial position.

5. The method for detecting the main drive angle and speed of a wind turbine generator according to claim 4, characterized in that, A GL fixed hub coordinate system is established with the hub center of the wind turbine as the origin. The initial position is when the Z-axis of the GL fixed hub coordinate system coincides with the axis of a specified blade, and the rotation angle of the main drive system at the initial position is set to 0°.

6. The method for detecting the main drive angle and speed of a wind turbine generator according to claim 4, characterized in that, When the proximity switch detects the screw and the metal detector, it outputs a high-level signal; otherwise, it outputs a low-level signal. Based on the detection signals output by the two proximity switches, the rotation angle of the main drive system is calculated using the following formula: Where Q represents the rotation angle of the main drive system, n represents the total number of bolts around the bearing clamping ring, K represents the bolt diameter, M is the distance between the bolts of two adjacent bolts, N represents the installation distance between the two proximity switches, K+M<N<2K+M and K+M<N<K+2M, a, b, c, and d represent the number of LL-line pulse signals, HL-line pulse signals, HH-line pulse signals, and LH-line pulse signals collected by the first and second proximity switches when the main drive system rotates in one direction, respectively, where L represents low level and H represents high level.

7. The method for detecting the main drive angle and speed of a wind turbine generator according to claim 6, characterized in that, When calculating the rotation angle of the main drive system relative to the preset initial position, the rotation direction of the main drive system is also determined according to the cyclic sequence of the pulse signals collected by the first proximity switch and the second proximity switch.

8. The method for detecting the main drive angle and speed of a wind turbine generator according to any one of claims 4-7, characterized in that, When the main drive system rotates clockwise, the rotation angle of the main drive system relative to the preset initial position is calculated using the following formula: θ = (Q + W) mod (360°) When the main drive system rotates counterclockwise, the rotation angle of the main drive system relative to the preset initial position is calculated using the following formula: θ = (360° - Q + W) mod (360°) Wherein, θ represents the rotation angle of the main drive system relative to the preset initial position, Q represents the rotation angle of the main drive system calculated based on the detection signals output by the two proximity switches, and W represents the first relative rotation angle.

9. The method for detecting the main drive angle and speed of a wind turbine generator according to claim 4, characterized in that, The rotational speed of the main drive system is calculated using the following formula: Where ω represents the rotational speed of the main drive system, θ represents the rotational angle of the main drive system relative to the preset initial position, and t represents time.

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