Fan blade position recognition device and fan control method and system

Abstract

The invention provides a fan blade position recognition device and a fan control method and system. The fan blade position recognition device comprises a coded disc and a proximity switch. The coded disc is synchronously and rotationally connected with the fan main shaft; the coded disc is in a circular ring shape, and multiple sets of positioning holes corresponding to fan blades in number are distributed in the coded disc. The plurality of groups of positioning holes are respectively distributed on a plurality of concentric circles which are spaced from the circle center of the code disc by different distances; each group of positioning holes comprises at least one positioning hole distributed in an arc-shaped area with the same distance with the circle center of the code disc; the number of the proximity switches is the same as that of fan blades, and the proximity switches face the code disc. Each group of proximity switches are respectively arranged on concentric circles corresponding to each group of positioning holes and respectively correspond to each group of positioning holes; when the code disc rotates and the positioning hole groups on the concentric circles pass through the corresponding proximity switches, the proximity switches generate pulse signals. According to the method, the blade which is about to run in a dangerous area which is possibly collided with the tower drum below the plane of the fan cabin can be identified.

Description

Technical Field

[0001] The present invention relates to the field of wind turbine generator set control technology, and in particular to a wind turbine blade position recognition device, a wind turbine control method and a wind turbine control system. Background Art

[0002] With the development of wind power generation technology and increasingly fierce competition in the wind power market, areas with poor wind quality, such as low wind speed and high turbulence, are gradually being developed. Especially in mountainous areas, due to narrow pipe terrain and gentle slopes, negative wind shear conditions are more likely to occur: with the increase of vertical height, the wind speed gradually decreases.

[0003] In order to improve economic benefits, the unit capacity and rotor diameter of wind turbines are constantly increasing, and the blades of wind turbines are getting longer and longer, with a significant decrease in stiffness. This makes the negative wind shear effect on wind turbines increasingly severe, with the direct impact being uneven force on the blades, which leads to increased root loads, not only significantly increasing the unbalanced load on the rotor surface, but also easily causing blades to sweep the tower, seriously endangering the safety of the entire machine.

[0004] At present, in order to solve the problem of wind turbine tower sweeping, some adopt the method of detecting the wind speed in front of the hub height and adjusting the blades in advance to reduce thrust. Some adopt the method of detecting the vertical wind shear in some areas in front of the hub and determine whether to change the blade position according to whether the wind speed change exceeds the threshold.

[0005] The prior art has the following defects: 1. When adjusting the blades in advance, the wind speed information at the hub height is used as a reference, but the wind speed below the hub height, which has a greater impact, is not involved, and the tower sweeping problem caused by negative wind shear cannot be solved well.

[0006] 2. The method of detecting wind shear in the vertical area in front of the hub is limited in detection range and cannot fully detect wind conditions at the entire blade height. In addition, the calculation is complex and the same pitch control for three blades cannot effectively avoid the risks brought by negative wind shear. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a wind turbine blade position identification device, a wind turbine control method and a system to identify blades that are about to run in a dangerous area below the plane of the wind turbine cabin and may collide with the tower, thereby solving the tower sweep problem caused by over-long blades under negative wind shear.

[0008] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a wind turbine blade position identification device, comprising a code disk and a proximity switch; The code disc is connected to the fan main shaft for synchronous rotation; the code disc is in a circular shape and has a plurality of groups of positioning holes corresponding to the number of fan blades; The multiple groups of positioning holes are respectively distributed on multiple concentric circles with different distances from the center of the code disk; each group of positioning holes includes at least one positioning hole distributed in an arc area with the same distance from the center of the code disk; The number of the proximity switches is the same as the number of the fan blades, and they are fixedly arranged toward the code disk; each group of proximity switches is respectively arranged toward the concentric circles corresponding to each group of positioning holes, and respectively corresponds to each group of positioning holes; When the code disk rotates and the positioning hole group on the concentric circle passes the corresponding proximity switch, the proximity switch generates a pulse signal, indicating that the blade corresponding to the positioning hole group is in the danger zone.

[0009] The effect achieved by the above settings is: a blade identification device that rotates with the main shaft of the wind turbine is used to identify blades that are about to run in the dangerous area below the plane of the wind turbine nacelle and may collide with the tower. The blades that are about to enter the dangerous area are identified by the code disk and proximity switch installed on the transmission chain. The position of the proximity switch can be freely set, because the relative position of the positioning hole and the blade can be freely set. As long as the proximity switch is close to the positioning hole, the corresponding blade position is in the dangerous area.

[0010] Furthermore, the dangerous area refers to the blade being located below a preset height plane.

[0011] The above settings achieve the effect that the danger zone represents the blades that may collide with the tower. The preset height plane can be the wind turbine nacelle plane, or the plane of half the blade length below the wind turbine nacelle plane, which can be set based on experience according to specific circumstances.

[0012] Furthermore, the number of the fan blades is 3; the number of the positioning holes is 3 groups; and the number of the proximity switches is 3.

[0013] The effect achieved by the above settings: 3 fan blades are a common setting, 3 sets of positioning holes and proximity switches are simple to set up and have low cost.

[0014] Furthermore, each group of positioning holes includes 5 positioning holes, which are distributed in an arc area with the same distance from the center of the code disk; the first hole of each group of positioning holes corresponds to the root centerline position of a blade.

[0015] The effect achieved by the above settings is: each group contains 5 positioning holes to improve the fault tolerance rate and redundant measurement to prevent the positioning holes from being missed due to too fast rotation speed, thereby causing misjudgment of the device.

[0016] The angle of the arc area of ​​a group of positioning holes is less than 90 degrees, which not only improves the response tolerance rate, but also prevents the warning moment from being too delayed due to the excessive angle distribution of the positioning holes, causing the blades to collide with the tower.

[0017] Furthermore, the code disc is mounted on the main shaft and can rotate synchronously with the main shaft.

[0018] The effect achieved by the above settings: the circular ring is suitable for being directly sleeved on the main shaft, which can effectively ensure the accuracy of detection.

[0019] Furthermore, three concentric circles corresponding to the three groups of positioning holes are evenly spaced and distributed on the annular surface of the code disk; and three proximity switches are evenly spaced and arranged in parallel, respectively facing the three concentric circles.

[0020] The effect achieved by the above settings: the equal spacing arrangement is more conducive to the setting of proximity switches and positioning holes.

[0021] Furthermore, the centers of the three groups of positioning holes around the code disk differ by 120 degrees; and the three proximity switches are horizontally placed on the fan frame.

[0022] The above settings achieve the following effect: the positions of the three blades are 120 degrees apart from each other.

[0023] In a second aspect, the present invention provides a wind turbine control method for dealing with complex wind conditions, comprising the following steps: The fan blade position identification device described in the first aspect performs blade identification detection to identify blades that have entered the danger zone.

[0024] The additional angle required for the blades to enter the danger zone is obtained and calculated based on the wind speed and direction information in the vertical direction of the wind turbine, and the value of the additional angle is added to the original angle of the blades.

[0025] When another blade enters the danger zone, the additional angle of the original blade is cancelled.

[0026] Furthermore, the wind speed and direction information in the vertical direction of the wind turbine is obtained, including: A nacelle-type laser radar anemometer is installed at the upper part and the lower part of the wind turbine nacelle respectively, and the two laser radar anemometers are provided with the same wind measurement reference surface, and the wind measurement reference surface is parallel to the rotation plane of the wind turbine impeller; The laser radar anemometer parameters are set according to the hub height, blade length and installation position of the laser radar anemometer, and the wind speed and direction information in the vertical direction of the wind turbine is measured within the wind measurement reference plane.

[0027] Furthermore, based on the wind speed and direction information in the vertical direction of the wind turbine, the additional angle required for the blades to enter the danger zone is calculated, including: When the blade enters the danger zone, the wind speed V at the lowest height of the fan blade tip is obtained after screening and processing based on the wind speed and direction information in the vertical direction of the fan. wlWind speed V at the centerline height of the nacelle hub .

[0028] Calculate the wind speed V at the lowest height of the fan blade tip wl Wind speed V at the centerline height of the nacelle hub The wind speed difference dV = (V wl -V hub ); Get the lowest tip height H leaL Height from hub centerline H hub The height difference dH = H hub -H leaL ; The rate of change of wind speed with height ρ=dV / dH is calculated based on the wind speed difference and height difference.

[0029] Get the preset cabin centerline height wind speed threshold V hubThr , and the wind speed change rate threshold ρ thr ; When the wind speed V at the centerline height of the nacelle hub Exceeding the wind speed threshold V at the centerline height of the cabin hubThr And the value of the rate of change of wind speed with height ρ exceeds the threshold value of the rate of change of wind speed with height ρ thr When the load is emulated, the additional angle value of each blade is calculated based on the load simulation.

[0030] The effect of the above settings is: the additional angle is added to the original angle value. The controller adjusts the blade to the corresponding angle, and the control system controls the three blades to expand at different angles according to their positions to reduce the blade sweeping problem caused by uneven thrust due to reverse wind shear.

[0031] Furthermore, the method further comprises: Real-time detection of the actual speed of the fan blades; The measured rotation speed is compared with the set rated rotation speed. If the rotation speed difference exceeds a threshold value, the original angle of the fan blades is readjusted.

[0032] In a third aspect, the present invention provides a wind turbine control system for coping with complex wind conditions, comprising: A main controller, used to execute the fan control method as described in the second aspect; The fan blade position identification device as described in the first aspect is used to perform blade identification detection and identify blades that have entered a dangerous area; Two nacelle-type lidar anemometers are installed on the upper and lower parts of the wind turbine nacelle respectively.

[0033] Effects achieved by the above settings: Installing nacelle-type laser radar anemometers at the upper and lower parts of the wind turbine nacelle can prevent the occurrence of measurement blind spots and improve measurement accuracy.

[0034] Compared with the prior art, the present invention has the following beneficial effects: 1. The position of the blade of the present invention is calibrated by a code disk, and the code disk detects the blade entering the dangerous area, thereby reducing the difficulty of calculation.

[0035] 2. The present invention can completely detect the wind condition information in the vertical direction through the upper and lower laser radar anemometers, and can completely detect the wind speed in the vertical direction; 3. The present invention adopts independent control of three blades to avoid the risk of tower sweeping. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram of the installation of a laser radar wind meter; In the figure: 11, laser radar anemometer; 12, cabin; 13, wind measurement reference surface; 14, minimum height of blade tip; 15, hub centerline.

[0037] Figure 2 It is a structural schematic diagram of a fan blade position recognition device; In the figure: 1. Ring code disk; 2. Positioning hole; 3. Proximity switch; 4. Center line of blade root; 5. Fan main shaft.

[0038] Figure 3 This is the control logic block diagram. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0040] Example 1: Figure 2 As shown, this embodiment provides a fan blade position identification device, including a code disk and a proximity switch 3; The code disc is connected to the fan main shaft 5 for synchronous rotation; the code disc is annular and has a plurality of groups of positioning holes 2 corresponding to the number of fan blades; The plurality of groups of positioning holes 2 are respectively distributed on a plurality of concentric circles at different distances from the center of the code disk; each group of positioning holes 2 includes at least one positioning hole 2 distributed in an arc region at the same distance from the center of the code disk; The number of the proximity switches 3 is the same as the number of the fan blades, and they are arranged toward the code disk; each group of proximity switches 3 is arranged on a concentric circle corresponding to each group of positioning holes 2, and corresponds to each group of positioning holes 2; When the code disk rotates and two groups of positioning holes on the concentric circles pass through the corresponding proximity switches 3, the proximity switches 3 generate pulse signals, indicating that the blades corresponding to the group of positioning holes 2 are in the danger zone.

[0041] The code disc installed on the transmission chain and the proximity switch 3 are used to identify the blade that is about to enter the danger zone. The position of the proximity switch 3 can be freely set, because the relative position between the positioning hole 2 and the blade can be freely set, as long as the proximity switch 3 is close to the positioning hole 2, the corresponding blade position is in the danger zone.

[0042] The danger zone refers to the blades being below the preset height plane. The danger zone means that the blades may collide with the tower. The preset height plane can be the plane of the wind turbine nacelle 12, or it can be the plane of half the blade length below the plane of the wind turbine nacelle 12. It can be set according to the specific situation, but at least it needs to include the blades at the bottom 60 degrees.

[0043] Specifically, the number of the fan blades is 3, the number of the positioning holes 2 is 3 groups, and the number of the proximity switches 3 is 3. Three fan blades are a common configuration, and the configuration of the three groups of positioning holes 2 and the proximity switches 3 is simple and has a low cost.

[0044] Preferably, each group of positioning holes 2 includes 5 positioning holes 2, which are distributed in an arc area with the same distance from the center of the code disk; the first hole of each group of positioning holes 2 corresponds to the root centerline position of a blade. Each group contains 5 positioning holes 2 to improve the fault tolerance rate and redundant measurement to prevent the rotation speed from being too fast and missing the positioning hole 2, thereby causing the device to misjudge.

[0045] Generally speaking, the angle of the arc area of ​​a group of positioning holes should be less than 90 degrees, preferably 60 degrees, which not only improves the response tolerance rate, but also prevents the warning moment from being too delayed due to the excessive distribution of the positioning holes.

[0046] The code disc is mounted on the main shaft and can rotate synchronously with the main shaft. The circular ring is suitable for being directly sleeved on the main shaft, which can effectively ensure the accuracy of detection.

[0047] The three concentric circles corresponding to the three groups of positioning holes 2 are evenly spaced and distributed on the annular surface of the code disk; the three proximity switches 3 are arranged in parallel at equal intervals and are respectively arranged toward the three concentric circles. The evenly spaced arrangement is more conducive to the arrangement of the proximity switches 3 and the positioning holes 2.

[0048] The center of the code disk of the three groups of positioning holes 2 differs by 120 degrees; three proximity switches 3 are placed horizontally on the fan frame. The difference of 120 degrees between the groups corresponds to the position of the three blades. The positions of the positioning holes 2 and the proximity switches 3 can be freely set, because the relative positions of the positioning holes 2 and the blades can be freely set.

[0049] Another optional form is to set three proximity switches 3 around the center of the code disk at a difference of 120 degrees, and arrange three groups of positioning holes 2 in parallel, so that each group of positioning holes 2 and the corresponding proximity switch 3 correspond to a concentric circle, thereby corresponding to the position relationship of a blade.

[0050] When in use, a ring-shaped code disc 11 which rotates with the main shaft is installed on the bearing nut of the fan main shaft 5 .

[0051] Three concentric circles of different radii are evenly spaced on the annular code disc 1. A group of positioning holes 2 is distributed on each circle, and each group consists of five adjacent holes. The first hole of each group of positioning holes 2 corresponds to the root centerline position of a blade. That is, each group of positioning holes 2 corresponds to a blade.

[0052] Three proximity switches 3 are installed on the plane of the fan frame. The proximity switches 3 are arranged in a row, and the radial positions correspond to the positioning holes 2 of the three sets of code disks, that is, the three proximity switches 3 correspond to the three sets of positioning holes 2. When the main shaft rotates, it drives the code disk to rotate. When the positioning hole 2 passes the proximity switch 3, the corresponding proximity switch 3 generates a pulse signal. According to different proximity switch 3 signals, the blade that is about to enter the dangerous area is identified.

[0053] Embodiment 2: This embodiment provides a fan control method for dealing with complex wind conditions, such as Figure 3 As shown, the following steps are included: Step 1: Perform blade identification detection based on the wind turbine blade position identification device described in Example 1 to identify blades that have entered the danger zone.

[0054] Step 2: Obtain and calculate the additional angle required for the blades to enter the danger zone based on the wind speed and direction information in the vertical direction of the wind turbine, and add the value of the additional angle to the original angle of the blades.

[0055] Step 3: When another blade enters the danger zone, cancel the additional angle of the original blade.

[0056] Specifically, a laser radar anemometer 11 is installed above and below the wind turbine nacelle 12 to measure wind speed and direction information on the blade rotation plane.

[0057] A blade identification device rotating with the wind turbine main shaft 5 is used to identify blades that are about to run in a dangerous area below the plane of the wind turbine nacelle 12 and may collide with the tower.

[0058] The control system uses wind direction and speed information, blade position, and control strategy to obtain the additional angle required for each blade. The additional angle is superimposed on the corresponding blade position to reduce the thrust on the blade in severe wind conditions and reduce the risk of wind turbine tower sweeping.

[0059] Specifically, the wind speed and direction information in the vertical direction of the wind turbine is obtained, including: The wind speed detection system of this system is installed as follows Figure 1 As shown, a nacelle 12-type laser radar anemometer 11 is installed on the upper and lower parts of the wind turbine nacelle 12, and the two laser radar anemometers 11 are provided with the same wind measurement reference surface 13, and the wind measurement reference surface 13 is parallel to the rotation plane of the wind turbine impeller. The upper and lower laser radar anemometers 11 aim to include the highest and lowest positions of the blade tip into the measurement range to avoid blind spots caused by the nacelle 12 and the blades.

[0060] The laser radar anemometer 11 parameters are set according to the position of the hub centerline 15, the length of the blade and the installation position of the laser radar anemometer 11, and the wind condition information at the lowest height 14 of the blade tip and the height of the hub centerline 15 of the nacelle 12 is measured in the reference plane.

[0061] The parameters of the laser radar anemometer 11 are set according to the hub height, the length of the blades and the installation position of the laser radar anemometer 11, and the wind speed and direction information in the vertical direction of the wind turbine is measured within the wind measurement reference surface 13.

[0062] Specifically, based on the wind speed and direction information in the vertical direction of the wind turbine, the additional angle required for the blades to enter the danger zone is calculated, including: When the blade enters the danger zone, the wind speed V at the lowest height of the fan blade tip is obtained after screening and processing based on the wind speed and direction information in the vertical direction of the fan. wl Wind speed V at the height of the hub centerline 15 of the nacelle 12 hub .

[0063] Calculate the wind speed V at the lowest height 14 of the fan blade tip wl Wind speed V at the height of the hub centerline 15 of the nacelle 12 hub The wind speed difference dV = (V wl -V hub ).

[0064] Get the lowest tip height H leaL 15H from the centerline of the wheel hub hub The height difference dH = H hub -HleaL, the height difference can be changed according to the lowest tip height HleaL stored in the system, which is 15 meters from the hub centerline hub It can be calculated or input by the operator.

[0065] The wind speed change rate with height ρ=dV / dH is calculated based on the wind speed difference and the height difference. The preset wind speed threshold V at the hub centerline 15 height of the nacelle 12 is obtained. hubThr and the wind speed change rate threshold ρthr .

[0066] When the wind speed V at the height of the hub centerline 15 of the nacelle 12 hub The wind speed threshold V at the height of the hub centerline 15 of the nacelle 12 is exceeded hubThr When the value of the rate of change of wind speed with height ρ exceeds the threshold value ρthr of the rate of change of wind speed with height, the additional angle value of each blade is calculated according to the load simulation.

[0067] When the wind speed V at the centerline height of the cabin hub The wind speed threshold V at the height of the hub centerline 15 of the nacelle 12 is exceeded hubThr And the value of the rate of change of wind speed with height ρ exceeds the threshold value of the rate of change of wind speed with height ρ thr This means that the lower blades in the danger zone may collide with the tower, so special adjustments need to be made to the angles of the lower blades at this time.

[0068] The specific additional angle value is generally calculated by load simulation software. Conventional fan load simulation software can be used for this purpose. Alternatively, the empirical value can be calculated by simulated load test. After multiple tests, the corresponding additional angle is recorded.

[0069] After the additional angle value is calculated, the additional angle is added to the original angle value. The controller adjusts the blade to the corresponding angle. The control system controls the three blades to expand at different angles according to their positions to reduce the blade sweeping problem caused by uneven thrust due to reverse wind shear.

[0070] The original angle is obtained according to the power mode, that is, the corresponding angle experience value pre-stored in the system is selected through the power generation mode of the wind turbine. This method is also a conventional method of the existing wind turbine blade angle control software. The determination of the original angle is determined by the wind turbine blade angle control system software. This method can be applied to conventional wind turbine blade angle control system software on the market, such as LabVIEW wind turbine intelligent blade control system.

[0071] like Figure 3 , the method further comprises: Real-time detection of the actual speed of the fan blades; The measured rotation speed is compared with the set rated rotation speed. If the rotation speed difference exceeds a threshold value, the original angle of the fan blades is readjusted.

[0072] Embodiment 3: This embodiment provides a wind turbine control system for dealing with complex wind conditions, including: A main controller, used to execute the fan control method as described in Example 2; The fan blade position identification device as described in Example 1 is used to perform blade identification detection and identify blades that have entered a dangerous area; Two nacelle 12-type laser radar anemometers 11 are installed at the upper part and the lower part of the wind turbine nacelle 12 respectively.

[0073] Specifically, this solution completely measures the wind condition information from the lowest blade tip height 14 to the highest blade tip height through the upper and lower laser radar anemometers 11 installed in the cabin 12, and simultaneously identifies the blades entering the dangerous area, and adopts three blades independent control method to avoid the risk of tower sweeping.

[0074] The specific installation and use methods of the fan control system include: 1. Use a laser radar anemometer 11 to measure wind speed and direction information in the area between the lowest blade tip height 14 and the hub centerline 15 height of the nacelle 12, and process the collected wind speed and direction as a directional vector; 1.1 Two laser radar wind meters 11 are installed on the top and bottom of the cabin 12.

[0075] 1.2 The laser radar anemometer 11 is set according to the blade length and the hub height of the wind turbine. The wind direction and wind speed information at the vertical height of the wind turbine blades can be measured as the standard, and the information is processed (data screening, wind condition information other than the two required points is deleted and eliminated) and then transmitted to the control system.

[0076] 2. Confirmation of blades in dangerous areas: The code disk in Embodiment 1 is combined with the proximity switch 3 to detect which blade is about to enter the dangerous area where it may collide with the tower.

[0077] 2.1 Install the code disc on the spindle nut, and the code disc rotates with the spindle.

[0078] 2.2 The code disk is a circular device with three concentric circles equally spaced on the ring surface. Each circle is distributed with a group of positioning holes 2. Each group of positioning holes 2 consists of 5 holes, and the difference between groups is 120 degrees, corresponding to the positions of three blades. When the fan rotates in the direction, the first hole of each code disk corresponds to the center of the root of a blade, which is used to distinguish different blades.

[0079] 2.3 Installation of proximity switches 3: A group of three horizontally placed proximity switches 3 are installed on the horizontal plane of the fan frame. The positions of the proximity switches 3 correspond to the three groups of positioning holes 2. When rotating, the three groups of positioning holes 2 pass through their corresponding proximity switches 3, and a signal is sent out to identify the blades that are about to enter the danger zone.

[0080] The position of the blade is determined by first determining the blade that enters the danger zone, and then determining the position of the other blades based on the relative position of the blades. When another blade enters the danger zone, the additional angle value of the previous blade is automatically cancelled, and the cycle continues.

[0081] 3. For blades entering the dangerous area, use the blade independent control method: Based on the original three blade angles, combined with the measured wind information, the additional angle of the blades in the dangerous area is simulated and calculated, as well as the additional angle of the remaining two blades to overcome vibration, and this angle is added to the original angle. The original angle is obtained according to the power mode, that is, the corresponding angle experience value pre-stored in the system is selected through the power generation mode of the wind turbine. This method is also a conventional method of existing wind turbine blade angle control software.

[0082] Figure 3 This is a block diagram of the wind turbine control method. Based on the wind condition information at the hub center height obtained by the laser radar anemometer 11, and the difference between the rated speed and the speed actually measured by the wind turbine's own encoder, the control system obtains the angle values ​​of the three blades according to the control strategy.

[0083] like Figure 1 As shown in FIG. 1 , when the blade enters the danger zone, the wind speed V at the lowest height 14 of the fan blade tip is obtained after screening and processing using the wind condition information obtained. wl Wind speed V at the height of the hub centerline 15 of the nacelle 12 hub .

[0084] Then calculate the wind speed V at the lowest height 14 of the fan blade tip wl Wind speed V at the height of the hub centerline 15 of the nacelle 12 hub The difference dV = (V wl -V hub ); Then calculate the lowest tip height H leaL 15H from the centerline of the wheel hub hub The height difference dH = H hub -H leaL ; Then calculate the rate of change of wind speed with height ρ = dV / dH.

[0085] Then, the wind speed threshold V at the hub centerline 15 height of the nacelle 12 is set according to the simulation results. hubThr , and the wind speed change rate threshold ρ thr The threshold value can be determined by empirical value or through specific experiments.

[0086] When V hub When the values ​​of ρ and ρ exceed the threshold, the additional angle value of each blade is calculated according to the load simulation, and the load simulation calculation is a prior art.

[0087] This additional angle is added to the original angle value, and the main controller adjusts the blade to the corresponding angle.

[0088] The main controller controls the three blades to unfold at different angles according to their positions, so as to reduce the blade sweeping tower problem caused by uneven thrust due to reverse wind shear.

[0089] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0090] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0091] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0092] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A fan blade position recognition device, characterized in that: Including code disc and proximity switch; The code disc is connected to the fan main shaft for synchronous rotation; the code disc is in a circular shape and has a plurality of groups of positioning holes corresponding to the number of fan blades; The multiple groups of positioning holes are respectively distributed on multiple concentric circles with different distances from the center of the code disk; each group of positioning holes includes at least one positioning hole distributed in an arc area with the same distance from the center of the code disk; The number of the proximity switches is the same as the number of the fan blades, and they are fixedly arranged toward the code disk; each group of proximity switches is respectively arranged toward the concentric circles corresponding to each group of positioning holes, and respectively corresponds to each group of positioning holes; When the code disk rotates and the positioning hole group on the concentric circle passes the corresponding proximity switch, the proximity switch generates a pulse signal, indicating that the blade corresponding to the positioning hole group is in the danger zone.

2. The fan blade position identification device according to claim 1, characterized in that: The number of the fan blades is 3; the number of the positioning holes is 3 groups; and the number of the proximity switches is 3.

3. The fan blade position identification device according to claim 2, characterized in that: Each group of positioning holes includes 5 positioning holes, which are distributed in an arc area with the same distance from the center of the code disk; the first hole of each group of positioning holes corresponds to the root center line position of a blade.

4. The fan blade position identification device according to claim 2, characterized in that: The three concentric circles corresponding to the three groups of positioning holes are evenly spaced and distributed on the annular surface of the code disk; the three proximity switches are evenly spaced and arranged in parallel, and are respectively set toward the three concentric circles.

5. The fan blade position identification device according to claim 4, characterized in that: The center points of the three groups of positioning holes differ by 120 degrees from the center point of the code disk; the three proximity switches are horizontally placed side by side on the fan frame.

6. A fan control method for dealing with complex wind conditions, characterized in that: The following steps are involved: Perform blade identification detection based on the fan blade position identification device according to claim 1 to identify blades that have entered the danger zone; Obtain and calculate the additional angle required for the blades to enter the danger zone based on the wind speed and direction information in the vertical direction of the wind turbine, and add the value of the additional angle to the original angle of the blades; When another blade enters the danger zone, the additional angle of the original blade is cancelled.

7. The wind turbine control method for dealing with complex wind conditions according to claim 6, characterized in that: Obtain wind speed and direction information in the vertical direction of the wind turbine, including: A nacelle-type laser radar anemometer is installed at the upper part and the lower part of the wind turbine nacelle respectively, and the two laser radar anemometers are provided with the same wind measurement reference surface, and the wind measurement reference surface is parallel to the rotation plane of the wind turbine impeller; The laser radar anemometer parameters are set according to the hub height, blade length and installation position of the laser radar anemometer, and the wind speed and direction information in the vertical direction of the wind turbine is measured within the wind measurement reference plane.

8. The wind turbine control method for dealing with complex wind conditions according to claim 6, characterized in that: Based on the wind speed and direction information in the vertical direction of the wind turbine, calculate the additional angle required for the blades to enter the danger zone, including: When the blade enters the danger zone, the wind speed V at the lowest height of the fan blade tip is obtained after screening and processing based on the wind speed and direction information in the vertical direction of the fan. wl Wind speed V at the centerline height of the nacelle hub ; Calculate the wind speed V at the lowest height of the fan blade tip wl Wind speed V at the centerline height of the nacelle hub The wind speed difference dV = (V wl -V hub ); Get the lowest tip height H leaL Height from hub centerline H hub The height difference dH = H hub -H leaL , Calculate the rate of change of wind speed with height ρ=dV / dH based on the wind speed difference and height difference; Get the wind speed threshold V at the centerline height of the cabin hubThr and the wind speed change rate threshold ρ thr ; When the wind speed V at the centerline height of the nacelle hub Exceeding the wind speed threshold V at the centerline height of the cabin hubThr And the value of the rate of change of wind speed with height ρ exceeds the threshold value of the rate of change of wind speed with height ρ thr When the load is emulated, the additional angle value of each blade is calculated based on the load simulation.

9. The wind turbine control method for dealing with complex wind conditions according to claim 6, characterized in that: The method further comprises: Real-time detection of the actual speed of the fan blades; The measured rotation speed is compared with the set rated rotation speed. If the rotation speed difference exceeds a threshold value, the original angle of the fan blades is readjusted.

10. A fan control system for coping with complex wind conditions, comprising: A main controller, configured to execute the fan control method according to claim 6; The fan blade position identification device according to claim 1 is used to perform blade identification detection and identify blades that have entered a dangerous area; Two nacelle-type lidar anemometers are installed on the upper and lower parts of the wind turbine nacelle respectively.

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