Anti-overspeed device for variable pitch system of wind generating set and control method

Abstract

The invention provides an anti-overspeed device and control method for a variable pitch system of a wind generating set, and the device comprises a control unit which is arranged in the variable pitch system; the rotating speed sensor is arranged in the hub and used for detecting the rotating speed of the hub to obtain a hub rotating speed detection value and sending the hub rotating speed detection value to the control unit; the vibration sensor is used for detecting hub vibration to obtain a hub vibration detection value and sending the hub vibration detection value to the control unit; and the control unit executes a paddle retracting action when the hub rotating speed detection value exceeds the preset rotating speed threshold value and the hub vibration detection value exceeds the preset vibration threshold value. According to the scheme, the safety of the variable pitch system is improved, safe operation of the wind generating set is ensured, and potential safety hazards and equipment damage are avoided.

Description

Technical Field

[0001] The present application relates to the field of wind power generation technology, and in particular to an anti-overspeed device and a control method for a pitch control system of a wind turbine generator set. Background Art

[0002] With the widespread application of wind power generation technology, the safety and stability of wind turbines during operation have become particularly important. As an important component of wind turbines, the safety of the pitch system is directly related to the operating efficiency and life of the entire unit.

[0003] Existing variable pitch systems rely on a master control system to prevent overspeed. The master control collects the main shaft and generator speeds, detects an overspeed fault based on these speeds, and transmits this information via slip rings to the variable pitch system, which then retracts the pitches. Therefore, the variable pitch system itself cannot detect speed fluctuations and initiate emergency retraction, which can easily lead to overspeed in certain situations, potentially causing safety hazards and equipment damage. Summary of the Invention

[0004] The technical problem to be solved by this application is that the wind turbine pitch system needs to rely on the main control to transmit the overspeed fault information before retracting the pitch when overspeed occurs, which poses a safety hazard. Therefore, an anti-overspeed device and control method for the wind turbine pitch system are provided.

[0005] In a first aspect, the technical solution of the present application provides an overspeed prevention device for a pitch control system of a wind turbine generator set, comprising:

[0006] a control unit disposed in the pitch system; and, disposed in the hub:

[0007] A speed sensor is used to detect the wheel hub speed, obtain a wheel hub speed detection value and send it to the control unit;

[0008] A vibration sensor is used to detect the vibration of the wheel hub, obtain the wheel hub vibration detection value and send it to the control unit;

[0009] The control unit performs a propeller retraction action when the hub speed detection value exceeds the preset speed threshold and the hub vibration detection value exceeds the preset vibration threshold.

[0010] Preferably, the control unit of the wind turbine generator set pitch control system overspeed prevention device includes:

[0011] an overspeed module, receiving the wheel hub speed detection value and outputting a first disconnection signal when the wheel hub speed detection value exceeds the preset speed threshold;

[0012] a vibration module, receiving the wheel hub vibration detection value and outputting a second disconnection signal when the wheel hub vibration detection value exceeds the preset vibration threshold;

[0013] a safety chain module, receiving output signals from the overspeed module and the vibration module, and outputting a disconnection control signal upon receiving the first disconnection signal or the second disconnection signal;

[0014] The relay group receives the output signal of the safety chain module, and is powered off after the safety chain module outputs a disconnection control signal, so that the pitch system performs an emergency pitch retraction action in the event of power failure.

[0015] Preferably, in the wind turbine generator set pitch system overspeed prevention device, the preset speed threshold and the preset vibration threshold are set according to the equipment information of the pitch system.

[0016] Preferably, the wind turbine generator set pitch control system overspeed prevention device further includes:

[0017] a bolt monitoring sensor, arranged in the hub, for detecting a current signal of a circuit where the blade bolt is located and sending the detection result to the control unit;

[0018] The control unit performs a blade retraction action when the current signal indicates that a blade bolt is broken.

[0019] Preferably, in the wind turbine generator set pitch control system overspeed prevention device, the control unit further comprises:

[0020] a bolt monitoring module, receiving the current signal, determining that a blade bolt is broken at the moment the current signal drops to zero and outputting a third disconnection signal;

[0021] The safety chain module receives the output signal of the bolt monitoring module and outputs a disconnection control signal when receiving the third disconnection signal.

[0022] Preferably, in the wind turbine generator set pitch control system overspeed prevention device, the bolt monitoring sensor includes:

[0023] A rubber ring is sleeved on the blade bolt, and a groove is formed on the outer surface of the rubber ring along the circumferential direction;

[0024] The short-circuit ring is embedded in the groove of some rubber rings, and some rubber rings are arranged at intervals;

[0025] The vortex spring is sleeved in the groove of the remaining rubber ring, and the two ends of each vortex spring are electrically connected to the short-circuit ring in the adjacent rubber ring;

[0026] A power supply, the two ends of which are respectively connected to the short-circuit ring / vortex spring at the first and last positions to obtain the circuit where the blade bolt is located;

[0027] The current sensor is connected in series in the circuit and is used to detect the current signal in the circuit.

[0028] Preferably, in the wind turbine generator set pitch system overspeed prevention device, the pitch system nacelle cover is provided with a metal patch;

[0029] The speed sensor is a scanner arranged on the wheel hub and rotates together with the wheel hub. The scanner scans the metal patch during the rotation of the wheel hub. The scanner determines the wheel hub speed detection value based on the number of times the metal patch is scanned and the scanning time.

[0030] Preferably, in the wind turbine generator set pitch control system overspeed prevention device, the metal patch includes multiple pieces, and the different metal patches are evenly distributed along the circumferential direction.

[0031] In a second aspect, the technical solution of the present application provides a method for preventing overspeed control of a pitch control system of a wind turbine generator set, comprising:

[0032] Obtain the hub speed detection value and hub vibration detection value of the pitch system;

[0033] Determining whether the wheel hub speed detection value exceeds a preset speed threshold, and determining whether the wheel hub vibration detection value exceeds a preset vibration threshold;

[0034] If the hub speed detection value exceeds the preset speed threshold, or the hub vibration detection value exceeds the preset vibration threshold, it is determined that the pitch system has an overspeed risk;

[0035] Control the pitch control system to perform pitch retraction.

[0036] Preferably, the wind turbine generator set pitch control system anti-overspeed control method further includes:

[0037] Obtaining a current signal of a circuit where the blade bolt is located;

[0038] determining whether the current signal indicates a blade bolt breakage;

[0039] If a blade bolt is broken, the pitch system is controlled to retract the blade.

[0040] Compared with the existing technology, the above technical solution provided by this application has the following technical effects:

[0041] This application provides an anti-overspeed device and control method for a wind turbine pitch control system. The pitch control system can determine whether an overspeed condition exists by assessing the hub speed and vibration conditions. If an overspeed condition is detected, emergency retraction of the pitches is achieved by powering off. This solution improves the safety of the pitch control system, ensuring the safe operation of the wind turbine and avoiding potential safety hazards and equipment damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a structural block diagram of an anti-overspeed device for a wind turbine pitch control system according to one embodiment of the present application;

[0043] Figure 2a This is a schematic diagram of the hardware structure of a control unit according to an embodiment of the present application;

[0044] Figure 2b This is a schematic diagram of the hardware structure of a control unit according to another embodiment of the present application;

[0045] Figure 3a This is a schematic structural diagram of a monitoring sensor according to an embodiment of the present application;

[0046] Figure 3b This is a schematic diagram of the assembly relationship between the bolt monitoring sensor and the bolt according to one embodiment of the present application;

[0047] Figure 4 This is a flow chart of an anti-overspeed control method for a wind turbine pitch system according to an embodiment of the present application;

[0048] Figure 5 This is a schematic diagram of the hardware connection relationship of the electronic equipment that executes the anti-overspeed control method of the wind turbine pitch system described in one embodiment of the present application. DETAILED DESCRIPTION

[0049] The specific implementation of this application is further described below with reference to the accompanying drawings.

[0050] It is easy to understand that according to the technical solution of this application, a variety of structural methods and implementation methods can be replaced with each other by those skilled in the art without changing the essential spirit of this application. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of this application and should not be regarded as the entire application or as a limitation or restriction of the technical solution of the application.

[0051] This embodiment provides an anti-overspeed device for a wind turbine pitch system. Figure 1 As shown, including:

[0052] A control unit is provided in the pitch system, specifically, in a pitch system control cabinet. Also provided in the wheel hub are: a rotation speed sensor for detecting the wheel hub rotation speed, obtaining a wheel hub rotation speed detection value, and sending it to the control unit; and a vibration sensor for detecting the wheel hub vibration, obtaining a wheel hub vibration detection value, and sending it to the control unit; the control unit executes a pitch retraction action when the wheel hub rotation speed detection value exceeds a preset rotation speed threshold or the wheel hub vibration detection value exceeds a preset vibration threshold.

[0053] In the above solution, the speed sensor and the vibration sensor can be selected from related products available in the prior art that are suitable for installation at corresponding positions of the wheel hub.

[0054] Preferably, the rotation speed sensor is a scanner mounted on the hub and rotating with the hub. The nacelle cover of the pitch system is provided with a metal patch. During the rotation of the hub, the scanner scans the metal patch and determines the hub rotation speed detection value based on the number of times the metal patch is scanned and the scanning duration. As the scanner rotates with the hub, it scans the metal patch once per revolution. The time interval between two adjacent scans of the metal patch can be used to determine the scanner's rotation speed, and thus the hub rotation speed. This solution enables simple and accurate detection of the hub rotation speed.

[0055] Further preferably, the metal patch comprises multiple pieces, with the different metal patches evenly distributed along the circumference. For example, metal patches are installed at the 3, 6, 9, and 12 o'clock positions on the nacelle cover facing the wheel hub surface. The scanner determines the wheel hub speed by scanning the metal patches on the nacelle cover. The metal patches in different positions can have different colors, shapes, etc. for differentiation, ensuring that the scanner accurately identifies the metal patches and, therefore, more accurately determines the wheel hub speed.

[0056] Through the above-mentioned solution of this application, the pitch control system can determine whether an overspeed condition exists by judging the hub speed and vibration conditions. If an overspeed condition is determined, emergency pitch retraction is achieved by powering off. This application solution improves the safety of the pitch control system, ensures the safe operation of the wind turbine generator set, and avoids safety hazards and equipment damage.

[0057] Furthermore, if Figure 2a As shown, the control unit in the wind turbine generator set pitch control system overspeed prevention device includes an overspeed module, a vibration module, a safety chain module and a relay group:

[0058] An overspeed module receives the hub speed detection value and outputs a first disconnect signal when the hub speed detection value exceeds the preset speed threshold. A vibration module receives the hub vibration detection value and outputs a second disconnect signal when the hub vibration detection value exceeds the preset vibration threshold. The preset speed threshold and the preset vibration threshold are set based on the device information of the pitch system. That is, in a specific implementation, different speed fault thresholds and vibration fault thresholds are set according to different models of pitch systems.

[0059] The safety chain module receives the output signals of the overspeed module and the vibration module and outputs a disconnection control signal upon receiving the first disconnection signal or the second disconnection signal. The operating signal of the safety chain can be preset. For example, the relay group can be de-energized after the safety chain outputs a zero signal.

[0060] The relay group receives the output signal of the safety chain module, and is powered off after the safety chain module outputs the disconnect control signal. The pitch system performs the emergency pitch retraction action when power is off. As shown in the figure, the relay group is connected to the main control EFC (Engineering fastest controller). If the relay group loses power, the main control EFC completes the emergency pitch retraction. The relay group includes a safety relay. The safety relay has four endpoints A1 to A4, wherein each pitch axis is also provided with a corresponding relay. The corresponding endpoints of the relays of the three pitch axes are A11-A12, A21-A22, and A31-A32, respectively. The relays of these three pitch axes are the original relays of the pitch system. In this solution, by controlling the two endpoints A1 and A2 of the safety relay to lose power, and controlling the A3 and A4 ports to be disconnected, the relay group as a whole loses power, and the pitch system can perform the emergency pitch retraction operation when power is off.

[0061] Furthermore, the wind turbine generator set pitch control system overspeed prevention device described in the above solution also includes:

[0062] The bolt monitoring sensor is arranged in the wheel hub and is used to detect the current signal of the circuit where the blade bolt is located and send the detection result to the control unit; the control unit performs the blade retraction action when the current signal indicates that the blade bolt is broken. Figure 2b As shown, the circuit in which the blade bolts are located does not mean that the blade bolts are connected in series or in parallel in the circuit, but rather that the normal operation of the circuit depends on the bolts being in a normal working state. The control unit also includes: a bolt monitoring module that receives the current signal, determines that a blade bolt is broken when the current signal drops to zero, and outputs a third disconnection signal; and a safety chain module that receives the output signal of the bolt monitoring module and outputs a disconnection control signal upon receiving the third disconnection signal. Through this solution, the pitch control system can urgently retract the blades when a blade bolt breaks.

[0063] In order to ensure the accuracy of bolt fracture monitoring and that the bolt fracture monitoring process does not affect the circuit stability of the entire device, this application scheme adopts the following Figure 3a and 3b The bolt monitoring sensor shown includes:

[0064] A rubber ring 11 is mounted on the blade bolt and has a circumferential groove formed on its exterior. Short-circuit rings 12 are embedded in the grooves of some rubber rings, with some other rubber rings arranged at intervals. A vortex spring 13 is mounted in the grooves of the remaining rubber rings, with the ends of each vortex spring electrically connected to the short-circuit rings in the adjacent rubber rings. A power supply, whose ends are connected to the first and last short-circuit rings / vortex springs, respectively, forms the circuit for the blade bolt. A current sensor is connected in series with the circuit to detect the current signal in the circuit. The power supply and current sensor can be placed in appropriate locations, as long as the short-circuit ring 12, vortex spring 13, power supply, and current sensor form a complete circuit.

[0065] like Figure 3a As shown, taking the five blade bolts L1 to L5 as an example, the short-circuit ring 12 is sleeved on the rubber rings of L1, L3 and L5, and the vortex spring 13 is sleeved on the rubber rings of L2 and L4. Both ends of the vortex spring 13 have extension legs, which can be electrically connected to the short-circuit ring 12. In specific implementation, the two can be electrically connected by welding. The welding point only needs to ensure that the short-circuit ring 12 and the extension leg are in fixed contact and will not be disconnected due to slight vibration. However, large displacements such as bolt breakage and falling off may cause the welding point to be disconnected, thereby disconnecting the circuit and the current sensor can no longer detect the current.

[0066] The present application also provides a method for preventing overspeed control of a wind turbine pitch system, which is applied to a pitch system. Figure 4 As shown, the method includes:

[0067] S100: Acquire a hub speed detection value and a hub vibration detection value of a pitch control system.

[0068] The wheel hub speed detection value is obtained by a speed sensor installed in the wheel hub; the wheel hub vibration detection value is obtained by a vibration sensor installed in the wheel hub. The speed sensor and the vibration sensor can be selected from related products available in the prior art that are suitable for installation at corresponding positions on the wheel hub.

[0069] S200: Determine whether the wheel hub speed detection value exceeds a preset speed threshold, and determine whether the wheel hub vibration detection value exceeds a preset vibration threshold.

[0070] S300: If the hub speed detection value exceeds the preset speed threshold, or the hub vibration detection value exceeds the preset vibration threshold, it is determined that the pitch system has an overspeed risk.

[0071] The preset speed threshold and the preset vibration threshold are set according to the device information of the pitch system. That is, in a specific implementation, different speed fault thresholds and vibration fault thresholds are set according to different models of pitch systems.

[0072] S400: Control the pitch control system to perform pitch retraction.

[0073] Propeller retraction control is achieved through a pre-set safety chain module in conjunction with a relay group.

[0074] The above method can automatically judge whether the hub is overspeeding or the vibration exceeds the limit and then quickly retract the blades, which improves the safety of the pitch system, ensures the safe operation of the wind turbine, and avoids safety hazards and equipment damage.

[0075] Preferably, the above method further comprises:

[0076] S500: Acquire a current signal of a circuit where the blade bolt is located.

[0077] A loop is formed by the short-circuit ring, vortex spring, power supply and current sensor. The short-circuit ring and vortex spring are fixed on the blade bolt. If the blade bolt breaks or falls off, the loop is disconnected and the current signal will suddenly drop to zero.

[0078] S600: Determine whether the current signal indicates that a blade bolt is broken.

[0079] As mentioned above, a sudden drop of the current signal to zero indicates that the blade bolt has broken and fallen off.

[0080] S700: If a blade bolt is broken, control the pitch control system to retract the blades.

[0081] In the above solution, the pitch control system can determine by itself whether the hub is overspeeding, the vibration is out of limit, or the blade bolts are broken. When any of the above situations occurs, the propellers can be quickly retracted and the machine can be shut down safely.

[0082] The present application also provides an electronic device, such as Figure 5As shown, the electronic device includes at least one processor 51 and at least one memory 52. ​​At least one memory 52 stores program information. After reading the program information, the at least one processor 51 executes the wind turbine pitch system overspeed prevention control method described in any of the above method embodiments. The device may also include an input device 53 and an output device 54. The processor 51, memory 52, input device 53, and output device 54 are communicatively connected. The memory 52, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. By running the non-volatile software programs, instructions, and modules stored in the memory 52, the processor 51 executes various functional applications and processes data, thereby implementing the wind turbine pitch system overspeed prevention control method provided in any of the above methods. The memory 52 may include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for the function; the data storage area may store data generated by the wind turbine pitch system overspeed prevention control method. In addition, the memory 52 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 52 may optionally include a memory remotely located relative to the processor 51, and these remote memories may be connected to a device for executing the wind turbine pitch system anti-overspeed control method via a network. Examples of the above-mentioned network include but are not limited to the Internet, corporate intranet, local area network, mobile communication network and a combination thereof. The input device 53 may receive input user clicks, and generate signal inputs related to user settings and function controls of the wind turbine pitch system anti-overspeed control method. The output device 54 may include a display device such as a display screen. When the one or more modules are stored in the memory 52 and are executed by the one or more processors 51, the wind turbine pitch system anti-overspeed control method in any of the above-mentioned method embodiments is executed.

[0083] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0084] The above are only the principles and preferred embodiments of the present application. It should be noted that, for those skilled in the art, on the basis of the principles of the present application, several other modifications can be made, which should also be considered as the scope of protection of the present application.

Claims

1. An anti-overspeed device for a wind turbine pitch system, characterized in that: include: A control unit is provided in the pitch system; And, disposed in the hub: A speed sensor is used to detect the wheel hub speed, obtain a wheel hub speed detection value and send it to the control unit; A vibration sensor is used to detect the vibration of the wheel hub, obtain the wheel hub vibration detection value and send it to the control unit; The control unit performs a propeller retraction action when the hub speed detection value exceeds the preset speed threshold and the hub vibration detection value exceeds the preset vibration threshold.

2. The wind turbine generator set pitch control system overspeed prevention device according to claim 1, characterized in that: The control unit comprises: an overspeed module, receiving the wheel hub speed detection value and outputting a first disconnection signal when the wheel hub speed detection value exceeds the preset speed threshold; a vibration module, receiving the wheel hub vibration detection value and outputting a second disconnection signal when the wheel hub vibration detection value exceeds the preset vibration threshold; a safety chain module, receiving output signals from the overspeed module and the vibration module, and outputting a disconnection control signal upon receiving the first disconnection signal or the second disconnection signal; The relay group receives the output signal of the safety chain module, and is powered off after the safety chain module outputs a disconnection control signal, so that the pitch system performs an emergency pitch retraction action in the event of power failure.

3. The wind turbine generator set pitch control system overspeed prevention device according to claim 2, characterized in that: The preset rotation speed threshold and the preset vibration threshold are set according to equipment information of the pitch system.

4. The wind turbine generator set pitch control system overspeed prevention device according to claim 2, characterized in that: Also includes: a bolt monitoring sensor, arranged in the hub, for detecting a current signal of a circuit where the blade bolt is located and sending the detection result to the control unit; The control unit performs a blade retraction action when the current signal indicates that a blade bolt is broken.

5. The wind turbine generator set pitch control system overspeed prevention device according to claim 4, characterized in that: The control unit further comprises: a bolt monitoring module, receiving the current signal, determining that a blade bolt is broken at the moment the current signal drops to zero and outputting a third disconnection signal; The safety chain module receives the output signal of the bolt monitoring module and outputs a disconnection control signal when receiving the third disconnection signal.

6. The wind turbine generator set pitch control system overspeed prevention device according to claim 5, characterized in that: The bolt monitoring sensor includes: A rubber ring is sleeved on the blade bolt, and a groove is formed on the outer surface of the rubber ring along the circumferential direction; The short-circuit ring is embedded in the groove of some rubber rings, and some rubber rings are arranged at intervals; The vortex spring is sleeved in the groove of the remaining rubber ring, and the two ends of each vortex spring are electrically connected to the short-circuit ring in the adjacent rubber ring; A power supply, the two ends of which are respectively connected to the short-circuit ring / vortex spring at the first and last positions to obtain the circuit where the blade bolt is located; The current sensor is connected in series in the circuit and is used to detect the current signal in the circuit.

7. The wind turbine generator set pitch control system overspeed prevention device according to any one of claims 1 to 6, characterized in that: The nacelle cover of the pitch system is provided with a metal patch; The speed sensor is a scanner arranged on the wheel hub and rotates together with the wheel hub. The scanner scans the metal patch during the rotation of the wheel hub. The scanner determines the wheel hub speed detection value based on the number of times the metal patch is scanned and the scanning time.

8. The wind turbine generator set pitch control system overspeed prevention device according to claim 7, characterized in that: The metal patch includes multiple pieces, and the different metal patches are evenly distributed along the circumferential direction.

9. A method for preventing overspeed control of a wind turbine pitch system, characterized in that: include: Obtain the hub speed detection value and hub vibration detection value of the pitch system; Determining whether the wheel hub speed detection value exceeds a preset speed threshold, and determining whether the wheel hub vibration detection value exceeds a preset vibration threshold; If the hub speed detection value exceeds the preset speed threshold, or the hub vibration detection value exceeds the preset vibration threshold, it is determined that the pitch system has an overspeed risk; Perform the paddle retraction motion.

10. The wind turbine generator set pitch control system overspeed prevention control method according to claim 9, characterized in that: Also includes: Obtaining a current signal of a circuit where the blade bolt is located; determining whether the current signal indicates a blade bolt breakage; If any blade bolt is broken, the blade will be retracted.

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