A control method and system for lubricating the tooth surface of a variable pitch bearing of a wind turbine generator system

Abstract

The application discloses a kind of wind generating set variable pitch bearing tooth surface lubrication control method and system, including steps: 1) determine timing cycle, grease frequency, open pitch angle and maximum lubrication duration;2) in every unit timing cycle, by unit state is judged, there are three situations: unit triggers wind, or fault, or a day does not trigger wind and fault and is in the state of continuous grid-connected, which situation triggers first, unit is in the situation and carries out variable pitch tooth surface lubrication grease, after grease is completed, variable pitch lubrication grease is not carried out in the day again.The application fully lubricates variable pitch bearing tooth surface without replacing hardware, prolongs the service life of variable pitch bearing, reduces the maintenance cost of wind generating set, and improves the power generation of wind generating set.

Description

Technical Field

[0001] This invention relates to the technical field of wind turbine generator control, and in particular to a control method and system for lubrication of the pitch bearing teeth of a wind turbine generator. Background Technology

[0002] With the development of wind power technology, large-scale variable pitch wind turbine generator sets are gradually achieving large-scale production and marketization. Manufacturers are increasingly emphasizing the daily maintenance and upkeep of major components, and the pitch bearing teeth, as a key component of wind power equipment, require a stable and reliable control method for lubrication.

[0003] The pitch bearing teeth of wind turbine generators are typically equipped with a centralized lubrication system. This centralized lubrication system can apply grease to the pitch bearing teeth to reduce friction and heat generation during pitch adjustment, thus making the pitch adjustment process smoother.

[0004] The existing 0° gear tooth surface lubrication structure uses a lubrication pinion installed next to the drive gear. The lubrication pinion first applies grease to the drive gear, which then transfers the grease to the bearing tooth surface through rotation. This method does not directly lubricate the meshing tooth surfaces. When wind turbines operate below rated wind speeds, their blades must remain at the 0° position, thus the pitch reducer and pitch bearing are also constantly meshed at the 0° tooth position. Insufficient grease on the tooth surfaces leads to poor lubrication of the pitch gear teeth. Over time, this can cause corrosion, wear, and even pitting and pitting on the 0° teeth of the pitch bearing and the corresponding meshing tooth surfaces of the pitch pinion. According to data collected through wind farm tracking services, pitch bearing tooth surface wear has become a significant problem.

[0005] Existing patent literature focuses on timed and metered lubrication or manual lubrication of pitch bearing tooth surfaces, but there are no relevant control strategies and methods for pitch bearing tooth surfaces under such a centrally installed lubrication system.

[0006] Currently, there are two main technical solutions in the industry to solve the lubrication problem of pitch bearings:

[0007] 1. Manual lubrication: Since the pitch bearing is located inside the hub, manual lubrication requires stopping the machine, which increases the maintenance cost of the wind turbine and causes a certain loss of power generation.

[0008] 2. Centralized lubrication of the pitch bearing, in its most common control method, involves an internal lubrication pump that automatically controls the lubrication time and frequency. However, due to the fixed position of the lubrication pinion, there are multiple tooth gaps between the oil outlet and the 0° pitch gear surface, preventing direct lubrication of the 0° position. This can lead to poor or failed lubrication of the pitch bearing gear surface, or even the pitch motor not rotating during lubrication, causing grease to accumulate in one place. This not only results in poor lubrication but also causes the grease to be flung by centrifugal force to any part of the hub, contaminating the working environment. Summary of the Invention

[0009] The primary objective of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a control method for lubrication of the pitch bearing tooth surface in wind turbine generator sets. This method can fully lubricate the pitch bearing tooth surface without replacing hardware, extend the service life of the pitch bearing, reduce the maintenance cost of wind turbine generator sets, and increase the power generation of wind turbine generator sets.

[0010] The second objective of this invention is to provide a control system for lubrication of the gear teeth of a wind turbine generator pitch bearing.

[0011] The first objective of this invention is achieved through the following technical solution: a control method for lubrication of the gear surface of a pitch bearing in a wind turbine generator set, comprising the following steps:

[0012] 1) Determine the timing cycle, number of grease applications, paddle opening angle, and maximum lubrication duration;

[0013] 2) Within a time cycle for each unit, the status of the unit is used to determine the situation. There are three possibilities: the unit triggers the wind standby mode, or a fault occurs, or the unit does not trigger the wind standby mode or a fault and is in a continuous grid-connected state. Whichever situation triggers first, the unit will perform pitch gear lubrication and grease application under that situation. After the grease application is completed, pitch gear lubrication and grease application will not be performed again on the same day.

[0014] Furthermore, in step 1), the timing period is determined as follows:

[0015] The pitch gear lubrication system runs once a day, with a 15-minute interval between the unit's zero points. The set time must be consistent with the interface time, and the calculation formula is as follows:

[0016] s0 = abs(f x -96)*15(1)

[0017] In the formula, f x Let s be the xth generator unit, and s0 be the zero point of the timing for the xth generator unit.

[0018] Furthermore, in step 1), the number of fat-reducing sessions is determined as follows:

[0019] The pitch gear lubrication system runs once a day, with grease injected g times. According to design requirements, the annual grease injection volume for each gear is h liters. Therefore, the formula for calculating the daily grease injection frequency is:

[0020] g=(h*1000*a) / b (2)

[0021] In the formula, a is the number of outlets of the lubrication pump, b is the volume of milliliters delivered to the pinion each time, and g is the number of times grease needs to be applied per day.

[0022] Furthermore, in step 1), the propeller angle is determined as follows:

[0023] When starting the propeller, the drive gear rotates counterclockwise. Lubrication is required for the 0° tooth. When n teeth remain, grease is injected at a fixed point to precisely deliver the grease to the 0° tooth. The corresponding calculation formula is:

[0024] p=(360 / m)*n (3)

[0025] In the formula, m is the number of teeth on the internal gear ring of the pitch bearing, n is the number of teeth at the fixed grease injection point at 0°, and p is the blade opening angle at the grease injection point.

[0026] Furthermore, in step 1), the longest lubrication time is determined as follows:

[0027] When a concentrated lubrication failure occurs, there will be a period of time during which no feedback signals are received until a concentrated lubrication failure is reported. Without additional judgment conditions, this can cause the pitch to run for an extended period at a certain point. The corresponding calculation formula is as follows:

[0028] t=[(b / k)*60]*g (4)

[0029] In the formula, k is the volume of milliliters pumped per minute by the lubrication pump, and t is the longest grease application time within a grease application cycle, i.e., the longest lubrication duration.

[0030] Furthermore, in step 2), the lubrication is performed according to three different situations of the unit during the timing cycle: waiting for wind shutdown lubrication, fault start lubrication, or continuous grid connection lubrication.

[0031] Furthermore, the specific details of the lubrication process during the standby shutdown are as follows:

[0032] Within a timer cycle for each unit, if the unit first triggers a standby shutdown, and after considering the unit's wind speed, wind direction, blade angle, and whether grease has been applied that day, the unit enters a standby grease-applying operation mode if the conditions are met. Before starting the propeller, the pitch gear lubrication pump is started to apply grease. After the program detects the jth grease application, the propeller starts. When the blade angle reaches p°, the propeller starts is paused. The unit's blades oscillate back and forth at the set pitch rate between p° and 6° until the j+10th grease application is detected. Then, the propeller starts again to 0° and oscillates back and forth twice between -1° and 10° before returning to standby. Grease application ends when the unit detects g grease applications or meets the maximum grease application time t. If, during the grease application process, the generator speed exceeds the set speed, the unit directly retracts the propeller to 89° and performs centralized lubrication to complete g grease applications. After that, the unit exits the lubrication and grease application mode, and centralized lubrication is not triggered again within the timer cycle.

[0033] Furthermore, the specific details of the faulty start-up and grease application are as follows:

[0034] Within a timing cycle of each unit, if the unit triggers a fault first, when restarting after the fault shutdown, the pitch tooth surface lubrication pump is started to inject grease before the propeller starts. After monitoring the jth grease injection count, the propeller starts. When the blade angle reaches p°, the propeller starts is paused until the j+10th grease injection count is monitored, and then the propeller starts again. The grease injection ends when the gth grease injection count is monitored or the longest grease injection time t is met.

[0035] Furthermore, the specific details of the continuous grid connection followed by grease removal are as follows:

[0036] If no grease is applied within a time cycle of each unit, active feathering is required. Before active feathering, the pitch tooth surface lubrication pump is started to apply grease. After monitoring the jth grease application count, feathering begins. When the blade angle reaches p°, feathering is paused until the (j+10)th grease application is monitored, at which point feathering is switched to open blades. Grease application ends when the gth grease application count is monitored or the longest grease application time t is met.

[0037] The second objective of this invention is achieved through the following technical solution: a control system for lubrication of the pitch bearing teeth of a wind turbine generator set, used to implement the above-mentioned control method for lubrication of the pitch bearing teeth of a wind turbine generator set, comprising:

[0038] The parameter determination module is used to determine the timing cycle, number of grease applications, paddle opening angle, and maximum lubrication duration.

[0039] The gear surface lubrication control module is used to determine the status of each unit within a timing cycle. There are three situations: the unit triggers the wind standby, or a fault occurs, or the unit is in a continuous grid-connected state without triggering either the wind standby or fault. The unit will be controlled to perform pitch gear surface lubrication grease under the first triggering condition. After the grease is completed, pitch lubrication grease will not be performed again on the same day.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] This invention lubricates the pitch bearing teeth under three different conditions within a time cycle: lubrication during wind wait, lubrication after a fault start-up, and lubrication after continuous grid connection. This ensures daily lubrication of the unit, bringing the grease to the 0° tooth position for further lubrication. It guarantees that the 0° tooth receives a certain amount of grease daily in most cases, ensuring that most lubrication occurs during pitch adjustment, providing optimal lubrication to the pitch bearing teeth without requiring additional hardware, thus reducing costs. This fully lubricates the pitch bearing teeth and increases the power generation of the wind turbine. Attached Figure Description

[0042] Figure 1 Diagram showing the lubrication process for the pitch control system, including grease application.

[0043] Figure 2 This is the flowchart for the wind-assisted pitch control.

[0044] Figure 3 This is a diagram showing the pitch and lubrication system during a fault start-up.

[0045] Figure 4 This is a flowchart of the fault start-up lubrication process.

[0046] Figure 5 Lubrication diagram for grid-connected pitch control.

[0047] Figure 6 Flowchart for connecting to the grid and lubricating the pitch.

[0048] Figure 7 This is an architecture diagram of the system of the present invention. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0050] Example 1

[0051] This embodiment discloses a control method for the lubrication of the gear teeth of a wind turbine generator pitch bearing, including the following steps:

[0052] 1) Determine the timing cycle, number of grease applications, paddle opening angle, and maximum lubrication duration;

[0053] a. Determine the timing period:

[0054] The pitch gear lubrication system runs once a day, with a 15-minute interval between the unit's zero points. The set time must be consistent with the interface time, and the calculation formula is as follows:

[0055] s0 = abs(f x -96)*15 (1)

[0056] In the formula, f x Let s be the xth generator unit, and s0 be the zero point of the timing for the xth generator unit.

[0057] b. Determine the number of fat removal sessions:

[0058] The variable propeller gear surface lubrication system runs once a day, with grease injected g times. According to design requirements, the annual grease injection volume for each gear is h liters. Therefore, the formula for calculating the number of grease injections per day is:

[0059] g=(h*1000*a) / b (2)

[0060] In the formula, a is the number of outlets of the lubrication pump, b is the volume of milliliters delivered to the pinion each time, and g is the number of times grease needs to be applied per day.

[0061] c. Determine the propeller angle:

[0062] When starting the propeller, the drive gear rotates counterclockwise. Lubrication is required for the 0° tooth. When n teeth remain, grease is injected at a fixed point to precisely deliver the grease to the 0° tooth. The corresponding calculation formula is:

[0063] p=(360 / m)*n (3)

[0064] In the formula, m is the number of teeth on the internal gear ring of the pitch bearing, n is the number of teeth at the fixed grease injection point at 0°, and p is the blade opening angle at the grease injection point.

[0065] d. Determine the maximum lubrication time:

[0066] When a concentrated lubrication failure occurs, there will be a period of time during which no feedback signals are received until a concentrated lubrication failure is reported. Without additional judgment conditions, this can cause the system to run at a certain point for an extended period during pitch control. The corresponding calculation formula is as follows:

[0067] t=[(b / k)*60]*g(4)

[0068] In the formula, k is the volume of milliliters pumped per minute by the lubrication pump, and t is the longest grease application time within a grease application cycle, i.e., the longest lubrication duration.

[0069] 2) Within a time period (24h) for each unit, the status of the unit is used to determine the situation. There are three situations: the unit is in standby mode, or there is a fault, or the unit is in continuous grid connection without triggering standby mode or fault. Depending on the three different situations of the unit within the time period, the following actions are performed: standby mode shutdown for grease application, fault start-up for grease application, or continuous grid connection for grease application. That is, whichever situation is triggered first, the unit will perform pitch gear lubrication grease application under that situation. After the grease application is completed, pitch lubrication grease application will not be performed again on the same day.

[0070] a. Wait for the fan to stop and then apply grease:

[0071] Within a 24-hour timer cycle for each unit, if the unit first triggers a wind-waiting shutdown, and after considering the unit's wind speed, wind direction, blade angle, and whether grease has been applied that day, the unit enters the wind-waiting grease-applying operation mode if the conditions are met. Before starting the propeller, the pitch gear lubrication pump is started to apply grease. After the program detects the j-th grease application, the propeller starts. When the blade angle reaches p°, the propeller starts again and stops. The unit's blades oscillate back and forth at the set pitch rate between p° and 6° until the j+10-th grease application is detected. Then, the propeller starts again to 0° and oscillates back and forth twice between -1° and 10° before returning to standby. Grease application ends when the unit detects g grease applications or meets the maximum grease application time t. If, during grease application, the generator speed exceeds the set speed, the unit immediately retracts the propeller to 89° and performs centralized lubrication to complete g grease applications. After that, the unit exits the lubrication and grease-applying mode, and centralized lubrication is not triggered again within the timer cycle. The wind-waiting grease-applying pitch lubrication is as follows: Figure 1 As shown, the process of waiting for the wind to grease and change pitch is as follows: Figure 2 As shown.

[0072] b. Faulty startup and lubrication:

[0073] Within a 24-hour timeframe for each unit, if a fault occurs first, upon restarting after a fault shutdown, the pitch gear lubrication pump is started to inject grease before the propellers are started. After monitoring the j-th grease injection count, the propellers are started. When the blade angle reaches p°, the propeller start is paused until the (j+10)-th grease injection count is monitored, after which the propeller start continues. Grease injection ends when the g-th grease injection count is monitored or the maximum grease injection time t is met. The fault-start pitch lubrication process is as follows: Figure 3 As shown, the fault start-up pitch control procedure is as follows: Figure 4 As shown.

[0074] c. Grease removal after continuous grid connection:

[0075] If no grease is applied within a 24-hour time period for each unit, active feathering is required. Before active feathering, the pitch gear lubrication pump is started to apply grease. After monitoring the j-th grease application count, feathering begins. When the blade angle reaches p°, feathering is paused until the (j+10)-th grease application count is monitored, at which point feathering switches to open pitching. Grease application ends when the g-th grease application count is monitored or the maximum grease application time t is met. Continuous grid-connected pitch lubrication is as follows: Figure 5 As shown, the continuous grid-connected pitch lubrication process is as follows: Figure 6 As shown.

[0076] Example 2

[0077] This embodiment discloses a control system for the lubrication of the pitch bearing teeth of a wind turbine generator set, used to implement the control method for the lubrication of the pitch bearing teeth of a wind turbine generator set described in Embodiment 1, such as... Figure 7 As shown, the system includes the following functional modules:

[0078] The parameter determination module is used to determine the timing cycle, number of grease applications, paddle opening angle, and maximum lubrication duration.

[0079] The gear surface lubrication control module is used to determine the status of each unit within a timing cycle. There are three situations: the unit triggers the wind standby, or a fault occurs, or the unit is in a continuous grid-connected state without triggering either the wind standby or fault. The unit will be controlled to perform pitch gear surface lubrication grease under the first triggering condition. After the grease is completed, pitch lubrication grease will not be performed again on the same day.

[0080] Example 3

[0081] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, it implements the control method for lubrication of the pitch bearing tooth surface of a wind turbine generator set as described in Embodiment 1.

[0082] The storage medium in this embodiment can be a disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), USB flash drive, portable hard drive, etc.

[0083] Example 4

[0084] This embodiment discloses a computing device, including a processor and a memory for storing processor-executable programs. When the processor executes the program stored in the memory, it implements the control method for lubrication of the pitch bearing tooth surface of the wind turbine generator described in Embodiment 1.

[0085] The computing device described in this embodiment may be a desktop computer, laptop computer, smartphone, PDA handheld terminal, tablet computer, programmable logic controller (PLC), or other terminal device with processor function.

[0086] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A control method for lubrication of the gear teeth of a wind turbine generator pitch bearing, characterized in that, Includes the following steps: 1) Determine the timing cycle, number of grease applications, paddle opening angle, and maximum lubrication duration; 2) Within a time cycle of each unit, the status of the unit is used to determine the situation. There are three possibilities: the unit triggers the wind standby, or a fault occurs, or the unit does not trigger the wind standby or fault and is in a continuous grid-connected state. Whichever situation triggers first, the unit will perform pitch gear lubrication and grease application under that situation. After the grease application is completed, pitch gear lubrication and grease application will not be performed again on the same day. The lubrication process is performed based on three different situations within the time period: waiting for wind to stop and lubricate, fault start-up and lubrication, or lubrication after continuous grid connection. The specific details of the lubrication process during the standby shutdown phase are as follows: Within a timer cycle for each unit, if the unit first triggers a standby shutdown, and after considering the unit's wind speed, wind direction, blade angle, and whether grease has been applied that day, the unit enters a standby grease-applying operation mode if the conditions are met. Before starting the propeller, the pitch gear lubrication pump is started to apply grease. After the program detects the jth grease application, the propeller starts. When the blade angle reaches p°, the propeller starts is paused. The unit's blades oscillate back and forth at the set pitch rate between p° and 6° until the j+10th grease application is detected. Then, the propeller starts again to 0° and oscillates back and forth twice between -1° and 10° before returning to standby. Grease application ends when the unit detects g grease applications or meets the maximum grease application time t. If, during the grease application process, the generator speed exceeds the set speed, the unit directly retracts the propeller to 89° and performs centralized lubrication to complete g grease applications. After that, the unit exits the lubrication and grease application mode, and centralized lubrication is not triggered again within the timer cycle.

2. The control method for lubrication of the gear teeth of a wind turbine generator pitch bearing according to claim 1, characterized in that, In step 1), the timing period is determined as follows: The pitch gear lubrication system runs once a day, with a 15-minute interval between the unit's zero points. The set time must be consistent with the interface time, and the calculation formula is as follows: s0 = abs(f x -96)*15(1) In the formula, f x Let s be the xth generator unit, and s0 be the zero point of the timing for the xth generator unit.

3. The control method for lubrication of the gear teeth of a wind turbine generator pitch bearing according to claim 2, characterized in that, In step 1), the number of fat-reducing sessions is determined as follows: The pitch gear lubrication system runs once a day, with grease injected g times. According to design requirements, the annual grease injection volume for each gear is h liters. Therefore, the formula for calculating the daily grease injection frequency is: g=(h*1000*a) / b(2) In the formula, a is the number of outlets of the lubrication pump, b is the volume of milliliters delivered to the pinion each time, and g is the number of times grease needs to be applied per day.

4. The control method for lubrication of the pitch bearing tooth surface of a wind turbine generator set according to claim 3, characterized in that, In step 1), the pitching angle is determined as follows: When starting the propeller, the drive gear rotates counterclockwise. Lubrication is required for the 0° tooth. When n teeth remain, grease is injected at a fixed point to precisely deliver the grease to the 0° tooth. The corresponding calculation formula is: p=(360 / m)*n(3) In the formula, m is the number of teeth on the internal gear ring of the pitch bearing, n is the number of teeth at the fixed grease injection point at 0°, and p is the blade opening angle at the grease injection point.

5. The control method for lubrication of the pitch bearing tooth surface of a wind turbine generator set according to claim 4, characterized in that, In step 1), the longest lubrication time is determined as follows: When a concentrated lubrication failure occurs, there will be a period of time during which no feedback signals are received until a concentrated lubrication failure is reported. Without additional judgment conditions, this can cause the pitch to run for an extended period at a certain point. The corresponding calculation formula is as follows: t=[(b / k)*60]*g(4) In the formula, k is the volume of milliliters pumped per minute by the lubrication pump, and t is the longest grease application time within a grease application cycle, i.e., the longest lubrication duration.

6. The control method for lubrication of the gear teeth of a wind turbine generator pitch bearing according to claim 1, characterized in that, The specific details of the faulty start-up and lubrication process are as follows: Within a timing cycle of each unit, if the unit triggers a fault first, when restarting after the fault shutdown, the pitch tooth surface lubrication pump is started to inject grease before the propeller starts. After monitoring the jth grease injection count, the propeller starts. When the blade angle reaches p°, the propeller starts is paused until the j+10th grease injection count is monitored, and then the propeller starts again. The grease injection ends when the gth grease injection count is monitored or the longest grease injection time t is met.

7. The control method for lubrication of the pitch bearing tooth surface of a wind turbine generator set according to claim 1, characterized in that, The specific details of the continuous grid connection followed by grease removal are as follows: If no grease is applied within a time cycle of each unit, active feathering is required. Before active feathering, the pitch tooth surface lubrication pump is started to apply grease. After monitoring the jth grease application count, feathering begins. When the blade angle reaches p°, feathering is paused until the (j+10)th grease application is monitored, at which point feathering is switched to open blades. Grease application ends when the gth grease application count is monitored or the longest grease application time t is met.

8. A control system for lubrication of the gear teeth of a wind turbine generator pitch bearing, characterized in that, A control method for achieving lubrication of the pitch bearing tooth surface of a wind turbine generator set as described in any one of claims 1 to 7, comprising: The parameter determination module is used to determine the timing cycle, number of grease applications, paddle opening angle, and maximum lubrication duration. The gear surface lubrication control module is used to determine the status of each unit within a timing cycle. There are three situations: the unit triggers the wind standby, or a fault occurs, or the unit is in a continuous grid-connected state without triggering either the wind standby or fault. The unit will be controlled to perform pitch gear surface lubrication grease under the first triggering condition. After the grease is completed, pitch lubrication grease will not be performed again on the same day.

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