Resonance point operation avoidance method for wind turbine generator
By automatically adjusting the wind turbine's speed and nacelle position, combined with the pitch control system and torque control, the problem of not being able to avoid resonance in the early stages of the wind turbine was solved, achieving stable operation and efficient power generation.
Patent Information
- Application Number
- CN202411672021.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-01-07
AI Technical Summary
Existing technologies cannot detect and automatically avoid resonance in the early stages of wind turbine resonance, leading to component damage or overall turbine failure, increasing maintenance costs and reducing power generation efficiency.
By automatically adjusting the wind turbine's speed and nacelle position, combined with the pitch control system and torque control, the system avoids resonance point operation in real time, and uses optimal speed and torque tracking technology, along with damping control, to stabilize the wind turbine.
It enables wind turbines to automatically avoid resonance areas, improving operational stability and reliability, reducing maintenance costs, and increasing power generation efficiency.
Smart Images
Figure CN119267093A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of wind turbine generator sets, and in particular to a method for avoiding resonance point operation of a wind turbine generator set. Background Art
[0002] Wind power generation uses wind energy to drive the blades of the wind turbine to rotate, and then drives the generator to rotate to convert wind energy into electrical energy. This method of power generation does not require fuel, so it will not pollute the environment, and therefore plays an important role in energy applications. With the development of wind power generation, more and more new wind farms are being opened up. At the same time, as the diameter of wind turbine blades increases, the height of the tower also increases accordingly, which brings great safety hazards to the safe and reliable operation of wind turbines and power grids.
[0003] Due to the high height, many parts and relatively complex mechanical structure of wind turbines, resonance is more likely to occur. Therefore, the design of the wind turbine structure and the overall design should be considered to avoid resonance during operation. Due to the height of the wind turbine, in order to facilitate transportation, wind turbine towers are mostly designed in sections. During the manufacturing and assembly process, the natural frequency of the wind turbine may shift, making resonance inevitable during operation.
[0004] The reason for the resonance of wind turbines is not only due to their own structural factors, but also to environmental factors and generator speed. If the wind direction is different from the direction of the wind turbine, the power generation efficiency will be affected. In addition, the same wind speed and speed will cause resonance. In this state, the wind turbine will suffer from load fatigue, which will greatly reduce the service life of the wind turbine and increase maintenance costs.
[0005] At present, the problem of resonance in wind turbines is generally solved by troubleshooting when the wind turbine parts are damaged, and then adopting corresponding solutions to reduce the resonance. This method cannot detect the cause of the resonance in the early stage of the resonance to avoid damage to the wind turbine parts or even the entire machine, which greatly affects the reliability of the wind turbine operation. There is also a method of collecting data with ultrasonic wind speed sensors and temperature sensors at certain time intervals, predicting the wind speed and wind direction through the data processing module and comparing them with the initial resonance setting value, and then controlling the wind turbine action by the controller to avoid the resonance problem. However, since the wind speed in the general environment of the wind farm is complex and uncontrollable, the accuracy of estimating the environmental wind speed and wind direction is relatively low, and it cannot effectively avoid the wind turbine from operating in the resonance point area.
[0006] At present, when a wind turbine has a resonance problem, most of the causes of the resonance are investigated only after damage to components or a malfunction in the wind turbine is discovered. The resonance of the wind turbine cannot be detected in time at the early stage of the resonance, and damage or malfunction of the components or the entire wind turbine cannot be avoided. After the resonance is diagnosed, the operation of the wind turbine cannot be automatically or actively adjusted to avoid the wind turbine operating at the resonance point, which greatly affects the reliability and power generation efficiency of the wind turbine during operation.
[0007] Another solution is to diagnose the natural frequency and operating frequency of each component of the wind turbine and the whole machine, screen suspicious units for frequency identification, and if resonance is diagnosed, the alarm module will alarm and notify the on-site operation and maintenance personnel. Although this solution can detect whether the wind turbine is resonating to a certain extent, the wind turbine does not have a corresponding control strategy to automatically adjust the operating status of the wind turbine in the first time, and it cannot avoid the reduction of the service life of the wind turbine after resonant operation. The diagnosis and maintenance by on-site operation and maintenance personnel also increases the labor cost of the wind farm. In addition, not every wind farm’s natural environment is suitable for long-term operation and maintenance personnel. The wind turbine cannot be adjusted automatically, which greatly increases the maintenance cost and also reduces the power generation efficiency of the wind turbine.
[0008] Another method is to collect data with ultrasonic wind speed sensors and temperature sensors at certain time intervals, and use the data processing module to predict the wind speed and wind direction and compare them with the initial resonance setting value, and then the controller controls the wind turbine to avoid the resonance problem. However, since the general environmental wind speed in wind farms is complex and uncontrollable, the accuracy of the estimated environmental wind speed and wind direction is relatively low, the time period is long, and it is impossible to make timely and accurate judgments, and it is impossible to avoid the wind turbine from operating in the resonance point area.
[0009] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention
[0010] The purpose of the present invention is to solve the technical problems existing in the background technology. To this end, a method for avoiding resonance point operation of a wind turbine is provided.
[0011] In order to achieve the above object, the technical solution adopted by the present invention is as follows:
[0012] A method for avoiding resonance point operation of a wind turbine generator set, comprising:
[0013] When the wind speed is within the wind speed range that causes resonance, the wind turbine generator speed setting is automatically adjusted to cross high speed or cross low speed, thereby preventing the wind turbine from running at a speed in the resonance area;
[0014] Automatically control the position of the wind turbine nacelle to prevent the wind turbine from vibrating and achieve optimal speed and torque tracking, so that the wind turbine can operate stably.
[0015] The following is a technical solution further defined by the present invention: during a certain period of time or at an initial time, when the wind speed is low, the speed of the wind turbine generator is maintained at a low speed before the resonance point crosses the region;
[0016] When the wind speed gradually increases to the high wind speed setting value, the speed of the wind turbine generator quickly rises to the high speed after the resonance point crosses the area at the set acceleration;
[0017] When the wind speed gradually decreases to the low wind speed setting value, the speed of the wind turbine generator drops rapidly at the set acceleration to the low speed before the resonance point crosses the area.
[0018] The following is a technical solution further defined by the present invention: if after the wind speed increases to a high wind speed, the wind speed no longer increases, and the speed of the wind turbine generator is maintained at a high speed after the resonance point crosses the region;
[0019] If the wind speed no longer decreases after it drops to a low wind speed, the speed of the wind turbine generator will remain at the low speed after the resonance point passes through the area.
[0020] The following is a technical solution further defined by the present invention. Within the wind speed delay loop area, if the wind turbine generator speed setting value corresponding to the wind speed is less than the resonance point speed setting value, the wind turbine generator speed changes toward the low boundary speed and eventually maintains at the low boundary speed; if the wind turbine generator speed setting value corresponding to the wind speed is greater than the resonance point speed setting value, the wind turbine generator speed changes toward the high boundary speed and eventually maintains at the high boundary speed.
[0021] The following is a technical solution further defined by the present invention: when the tower has a tendency to vibrate forward, the nacelle of the wind turbine moves forward, so that the pitch angle is reduced, the impeller thrust is increased, and the forward vibration of the tower of the wind turbine is prevented;
[0022] When the tower tends to vibrate backward, the wind turbine nacelle moves backward, increasing the pitch angle, reducing the impeller thrust, and preventing the wind turbine tower from vibrating backward.
[0023] When the tower tends to vibrate to the left, the wind turbine increases negative torque, causing the tower to bend positively, preventing the wind turbine tower from vibrating to the left;
[0024] When the tower tends to vibrate to the right, the wind turbine increases the positive torque, causing the tower to bend negatively, thus preventing the wind turbine tower from vibrating to the right.
[0025] The following is a technical solution further defined by the present invention, based on the power factor K λ , calculate the current wind wheel optimal efficiency torque T:
[0026]
[0027] T=K λ ω 2
[0028] ω is the angular velocity of the wind turbine rotor; λ is the desired tip speed ratio; C ρ is the efficiency corresponding to the tip speed ratio; R is the radius of the wind wheel; ρ is the air density.
[0029] According to the formula T = K λ ω 2 By making the optimal control curve of the wind turbine, and controlling the relationship between the output torque of the wind turbine and the speed of the wind turbine to coincide with the optimal control curve, the optimal speed and torque tracking can be achieved.
[0030] Compared with the prior art, the present invention has the following technical effects:
[0031] The present invention can automatically adjust and reduce the wind turbine set running in the resonance area due to its own natural frequency and the wind rotor speed, and adjust the wind turbine set vibration caused by the speed change, avoid the wind turbine set running in the resonance area, and improve the stability and reliability of the wind turbine set operation.
[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0034] Figure 1 It is the speed torque control curve diagram of the wind turbine;
[0035] Figure 2 is a diagram showing the relationship between the generator speed and the wind speed of the present invention;
[0036] Figure 3 This is the optimal control curve diagram of the wind turbine generator set of the present invention. DETAILED DESCRIPTION
[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.
[0038] At present, the mainstream tower is mainly made of rigid materials, and the first-order modal frequency of the tower is between 1 times the rotational frequency (1P) and 3 times the rotational frequency (3P) of the wind rotor. As the design height of the wind turbine increases, the first-order modal frequency of the tower is also continuously reduced. For the design of such towers, the first-order tower left and right front and back inherent frequency and the wind turbine rotor 1P crossover frequency may cause resonance during operation, affecting the stable operation of the wind turbine. Wind turbines usually have similar Figure 1 The speed torque control curve is shown. In order to avoid the coupling interference of the natural frequency during the operation of the wind turbine, the following processing is performed:
[0039] When the wind speed is within the wind speed range that causes resonance, the wind turbine generator speed setting is automatically adjusted to cross high speed or cross low speed to prevent the wind turbine from running at a speed in the resonance area.
[0040] like Figure 2 As shown, this is the relationship between the generator speed and wind speed in the resonance area of the wind turbine:
[0041] During a certain period of time, or at the initial time, when the wind speed is low, the wind turbine speed is maintained at Figure 1 Low speed before the mid-resonance point crosses the area.
[0042] When the wind speed gradually increases to a certain high wind speed value (this value is a set value and can be customized), the speed of the wind turbine generator rises rapidly at a certain acceleration to Figure 1 High speed after the mid-resonance point crosses the area.
[0043] When the wind speed gradually decreases to a certain low wind speed value (this value is a set value and can be customized), the speed of the wind turbine generator drops rapidly at a certain acceleration to Figure 1 Low speed before the mid-resonance point crosses the area.
[0044] If the wind speed stops increasing after it increases to a high wind speed, the speed of the wind turbine generator will remain at the high speed after the resonance point passes through the area.
[0045] If the wind speed no longer decreases after it drops to a low wind speed, the speed of the wind turbine generator will remain at the low speed after the resonance point passes through the area.
[0046] When the wind speed is within the wind speed delay loop area, if the wind turbine generator speed setting value corresponding to the wind speed is less than the resonance point speed setting value, the wind turbine generator speed changes toward the low boundary speed and eventually maintains at the low boundary speed; if the wind turbine generator speed setting value corresponding to the wind speed is greater than the speed setting value, the wind turbine generator speed changes toward the high boundary speed and eventually maintains at the high boundary speed.
[0047] During the actual operation of a wind turbine, changes in speed may cause unbalanced force on the blades and excessive vibration of the wind turbine, including vibration of the cabin along the wind speed direction and lateral vibration of the cabin. This may cause the cabin to shake, and the yaw and other limit positions may be affected by the vibration, causing noise and even damage to the interior of the cabin, causing a series of faults that interfere with normal operation.
[0048] The present invention uses the front and rear damping control technology of the variable pitch system and the left and right damping control technology based on the generator torque to cope with the occurrence of such vibrations in the operation of the wind turbine, automatically controls the position of the nacelle to prevent the vibration of the wind turbine and achieve the optimal speed and torque tracking, so that the wind turbine can operate stably and improve the power generation efficiency.
[0049] When the tower tends to vibrate forward, the wind turbine nacelle moves forward, which reduces the pitch angle, increases the impeller thrust, and prevents the wind turbine tower from vibrating forward.
[0050] When the tower tends to vibrate backward, the wind turbine nacelle moves backward, increasing the pitch angle, reducing the impeller thrust, and preventing the wind turbine tower from vibrating backward.
[0051] When the tower tends to vibrate to the left, the wind turbine increases negative torque, causing the tower to bend positively, preventing the wind turbine tower from vibrating to the left;
[0052] When the tower tends to vibrate to the right, the wind turbine increases the positive torque, causing the tower to bend negatively, thus preventing the wind turbine tower from vibrating to the right.
[0053] Introduce the formula:
[0054]
[0055] λ is the desired tip speed ratio; C ρ is the efficiency corresponding to the tip speed ratio; R is the radius of the wind wheel; ρ is the air density; K λ is the power factor.
[0056] The parameters of the power factor calculated by the above formula are all known quantities, and the optimal efficiency torque T of the current wind wheel can be calculated:
[0057] T=K λ ω 2
[0058] ω is the angular velocity of the wind turbine rotor, which can be measured by sensors. According to this formula, the optimal control curve of the wind turbine can be drawn, such as Figure 3 shown.
[0059] like Figure 3 As shown, the speed of the wind turbine is monitored, and the speed area is divided at a certain interval, and the switching point is based on S2 (S2 = (S1 + S3) / 2): when the speed is lower than S2, the target speed of the wind turbine is S1, and the maximum output torque of the wind turbine is the output torque value at S2, and the minimum output torque is the output torque value at S1; when the speed is higher than S2, the target speed of the wind turbine is S3, and the maximum output torque is the output torque value at S3, and the minimum output torque is the output torque value at S2. In this section of BE, S2 is used as the switching point control to achieve a certain speed range. At low speed (<S2), the actual speed of the wind turbine is controlled to be not less than S1, and at high speed (>S2), the actual speed of the wind turbine is controlled to be not more than S3, and at the same time, it is made to coincide with the optimal control curve, so as to achieve optimal speed and torque tracking.
[0060] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, all equivalent changes made according to the shape, structure and principle of the present invention without departing from the content of the technical solution of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for avoiding resonance point operation of a wind turbine generator set, characterized in that: include: When the wind speed is within the wind speed range that causes resonance, the wind turbine generator speed setting is automatically adjusted to cross high speed or cross low speed, thereby preventing the wind turbine from running at a speed in the resonance area; Automatically control the position of the wind turbine nacelle to prevent the wind turbine from vibrating and achieve optimal speed and torque tracking, so that the wind turbine can operate stably.
2. A method for avoiding resonance point operation of a wind turbine generator set as claimed in claim 1, characterized in that: During a certain period of time or at the initial time, when the wind speed is low, the speed of the wind turbine generator is kept at a low speed before the resonance point crosses the area; When the wind speed gradually increases to the high wind speed setting value, the speed of the wind turbine generator quickly rises to the high speed after the resonance point crosses the area at the set acceleration; When the wind speed gradually decreases to the low wind speed setting value, the speed of the wind turbine generator drops rapidly at the set acceleration to the low speed before the resonance point crosses the area.
3. A method for avoiding resonance point operation of a wind turbine generator set as claimed in claim 2, characterized in that: If the wind speed does not increase any more after it increases to a high wind speed, the wind turbine speed will remain at the high speed after the resonance point passes through the area; If the wind speed no longer decreases after it drops to a low wind speed, the speed of the wind turbine generator will remain at the low speed after the resonance point passes through the area.
4. A method for avoiding resonance point operation of a wind turbine generator set as claimed in claim 2, characterized in that: When the wind speed is within the wind speed delay loop area, if the wind turbine generator speed setting value corresponding to the wind speed is less than the resonance point speed setting value, the wind turbine generator speed changes toward the low boundary speed and eventually maintains at the low boundary speed; if the wind turbine generator speed setting value corresponding to the wind speed is greater than the resonance point speed setting value, the wind turbine generator speed changes toward the high boundary speed and eventually maintains at the high boundary speed.
5. A method for avoiding resonance point operation of a wind turbine generator set as claimed in claim 1, characterized in that: When the tower tends to vibrate forward, the wind turbine nacelle moves forward, which reduces the pitch angle, increases the impeller thrust, and prevents the wind turbine tower from vibrating forward. When the tower tends to vibrate backward, the wind turbine nacelle moves backward, increasing the pitch angle, reducing the impeller thrust, and preventing the wind turbine tower from vibrating backward. When the tower tends to vibrate to the left, the wind turbine increases negative torque, causing the tower to bend positively, preventing the wind turbine tower from vibrating to the left; When the tower tends to vibrate to the right, the wind turbine increases the positive torque, causing the tower to bend negatively, thus preventing the wind turbine tower from vibrating to the right.