Method and device for adding resistance to front and back vibrations of a tower of a large wind turbine

Abstract

The application relates to the technical field of wind power generation, in particular to a method and device for adding resistance to front and back vibrations of a tower of a large wind turbine, wherein the method comprises the following steps: establishing a nonlinear model of the wind turbine by considering the front and back vibrations of the tower based on a pre-established model, obtaining an equivalent resistance analysis result of a second-order dynamic equation of the front and back vibrations of the tower, and obtaining a tower vibration peak frequency under different rotating speeds according to the equivalent resistance analysis result, so that an additional variable pitch rate for adding resistance to the tower is generated according to the tower vibration peak frequency, and the additional variable pitch rate is used for adding resistance to the vibration. Therefore, the problems that in the related art, due to the poor environment, the performance of the sensor is reduced, the transmission data is inaccurate, the system complexity is high but the algorithm adaptability is insufficient, the implementation is not easy, the cost is high and the like are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind power generation, and in particular to a tower front and rear vibration damping method and device for a large wind turbine. BACKGROUND

[0002] In related technologies, the tower front and rear vibration damping method for a large wind turbine usually installs monitoring devices such as acceleration sensors and strain sensors on the tower to obtain the vibration state of the tower in real time, and transmits the monitoring data to a controller. The controller calculates the control force to be applied according to a certain control algorithm, and then applies a reverse force to the tower through an executing mechanism (such as a motor-driven variable pitch system or an additional actuator) to suppress vibration.

[0003] However, in related technologies, on the one hand, the harsh environment can affect the reliability and durability of the sensors, and problems such as performance degradation and damage are prone to occur, resulting in inaccurate data, increased maintenance costs and downtime, and data transmission is prone to interference and difficult to process. On the other hand, the actual working conditions are complex and variable, the corresponding system complexity is high, the algorithm adaptability is insufficient, and the cost is increased, and there are many fault risk points, which need to be improved. SUMMARY

[0004] The present application provides a tower front and rear vibration damping method and device for a large wind turbine to solve the problem in related technologies that the performance of the sensor is degraded due to the harsh environment, resulting in inaccurate data transmission, and the system complexity is high but the algorithm adaptability is insufficient, making it difficult to implement and increasing the cost.

[0005] The first aspect of the present application provides a tower front and rear vibration damping method for a large wind turbine, comprising the following steps: establishing a nonlinear model of a wind turbine considering tower front and rear vibration based on a pre-established wind turbine, obtaining the equivalent damping analysis result of the second order dynamic equation of the tower front and rear vibration; obtaining the tower vibration peak frequency under different rotational speeds according to the equivalent damping analysis result; generating an additional variable pitch rate for tower damping according to the tower vibration peak frequency, and using the additional variable pitch rate for vibration damping.

[0006] Through the above technical solution, the present application can obtain the tower vibration peak frequency based on the established nonlinear model and the equivalent damping analysis result, and then generate an additional variable pitch rate for vibration damping, effectively suppress the tower front and rear vibration, enhance the tower stability, reduce the fatigue load caused by vibration, and thus reduce the operation and maintenance cost of the wind turbine and prolong its service life.

[0007] Optionally, in an embodiment of the present application, the vibration resistance adding by using the additional pitch rate comprises: adding the additional pitch rate and a reference pitch rate for controlling the rotating speed to generate a total pitch rate instruction value.

[0008] Through the above technical solution, the embodiment of the present application can effectively integrate different pitch rates by adding the additional pitch rate and the reference pitch rate for controlling the rotating speed to generate a total pitch rate instruction value. On the one hand, the addition of the additional pitch rate brings an additional adjustment factor to the system, which can more accurately adapt to different working condition requirements. On the other hand, the addition method is relatively simple and direct, easy to implement in the existing pitch rate control system, and can quickly realize the addition of the vibration resistance function without completely changing the original reference pitch rate control logic, thereby improving the stability and reliability of the entire system in dealing with vibration.

[0009] Optionally, in an embodiment of the present application, the additional pitch rate for tower resistance generated according to the tower vibration peak frequency comprises: inputting at least one center frequency and at least one shear frequency of the tower vibration peak frequency into a preset proportional resonance controller respectively to output the additional pitch rate.

[0010] Through the above technical solution, the embodiment of the present application can accurately respond to the key characteristics of tower vibration by taking the center frequency and shear frequency of the tower vibration peak frequency as input, and use the proportional resonance controller to output the additional pitch rate. With the preset proportion and resonance functions of the controller, the input frequency can be accurately processed and converted, thereby generating a more appropriate and effective additional pitch rate, which helps to improve the effect of tower resistance and enhance the stability of the tower during operation, and reduce the risks and losses that may be caused by vibration.

[0011] Optionally, in an embodiment of the present application, the expression of the nonlinear model established by the wind turbine is:

[0012]

[0013] wherein, Ω r is the rotating speed of the wind wheel, T a is the aerodynamic torque, T e is the electromagnetic torque of the generator, x t is the displacement of the tower top, β is the unified pitch angle, v0 is the effective wind speed of the wind wheel, G is the gear ratio of the gearbox, J is the equivalent moment of inertia, M t is the equivalent modal mass of the tower, C t is the structural damping of the tower, K t is the bending stiffness of the tower, F aF1 is the wave load acting force equivalent to the tower top, F2 is the aerodynamic force equivalent to the tower top from the wind directly acting on the tower, T ac is the time constant of the variable pitch actuator, β * is the output instruction value of the variable pitch controller.

[0014] Through the above technical solutions, the embodiment of the application can accurately present the complex dynamic characteristics of the actual operation of the wind turbine, cover the key degrees of freedom and mutual coupling relationship, accurately simulate the nonlinear factors such as aerodynamic thrust and torque, and is beneficial to optimizing power tracking and improving power generation efficiency.

[0015] Optionally, in an embodiment of the application, the calculation formula of the additional pitch rate is:

[0016]

[0017] wherein, is the output additional pitch rate of the i-th proportional resonant controller, ω ci is the shear frequency input to the i-th proportional resonant controller, ω i is the center frequency input to the i-th proportional resonant controller, x t is the tower top displacement, K Pi is the proportional control gain, K Ri is the resonant control gain.

[0018] Through the above technical solutions, the additional pitch rate calculation formula of the embodiment of the application is derived based on the tower front and rear vibration system characteristics and related analysis, and is proportional to the tower front and rear vibration acceleration, so that the additional pitch rate can be easily calculated by monitoring the vibration acceleration, thereby providing a direct and effective means for realizing accurate vibration control.

[0019] The second aspect embodiment of the application provides a tower front and rear vibration damping device of a large wind turbine, comprising: a first acquisition module configured to acquire an equivalent damping analysis result of a second-order dynamic equation of tower front and rear vibration based on a pre-established nonlinear model of a wind turbine considering tower front and rear vibration; a second acquisition module configured to acquire tower vibration peak frequency under different rotational speeds according to the equivalent damping analysis result; and a vibration damping module configured to generate an additional pitch rate for tower damping according to the tower vibration peak frequency, so as to utilize the additional pitch rate for vibration damping.

[0020] By the technical solution, the tower vibration peak frequency can be obtained based on the established nonlinear model and the equivalent added resistance analysis result, and then the additional variable pitch rate is generated to add resistance to vibration, so as to effectively suppress the front and rear vibration of the tower, enhance the stability of the tower, reduce the fatigue load caused by vibration, thereby reducing the operation and maintenance cost of the wind turbine generator and prolonging the service life thereof.

[0021] Optionally, in an embodiment of the present application, the vibration resistance adding module comprises a generating unit configured to add the additional variable pitch rate to a reference variable pitch rate used for controlling the rotating speed to generate a total variable pitch rate instruction value.

[0022] By the technical solution, the total variable pitch rate instruction value can be generated by adding the additional variable pitch rate to the reference variable pitch rate used for controlling the rotating speed, so as to effectively integrate different variable pitch rates. On the one hand, the additional variable pitch rate brings an additional adjustment factor to the system, which can more accurately adapt to different working condition requirements. On the other hand, the adding method is relatively simple and direct, and is easy to implement in the existing variable pitch rate control system. The vibration resistance adding function can be quickly added without completely changing the original reference variable pitch rate control logic, thereby improving the stability and reliability of the entire system in dealing with vibration.

[0023] Optionally, in an embodiment of the present application, the vibration resistance adding module comprises an output unit configured to input at least one center frequency and at least one shear frequency of the tower vibration peak frequency into a preset proportional resonance controller respectively to output the additional variable pitch rate.

[0024] By the technical solution, the center frequency and the shear frequency of the tower vibration peak frequency can be used as inputs to accurately respond to the key characteristics of the tower vibration. The proportional resonance controller is used to output the additional variable pitch rate. With the preset proportional and resonance functions of the controller, the input frequency can be accurately processed and converted, so as to generate a more appropriate and effective additional variable pitch rate, which helps to improve the effect of adding resistance to the tower, enhance the stability of the tower during operation, and reduce the risks and losses caused by vibration.

[0025] Optionally, in an embodiment of the present application, the expression of the nonlinear model established by the wind turbine generator is as follows:

[0026]

[0027] wherein, Ω r is the rotating speed of the wind wheel, T a is the aerodynamic torque, T e is the electromagnetic torque of the generator, x tis the top displacement of the tower, β is the uniform pitch angle, v0 is the effective wind speed of the wind wheel, G is the gear ratio of the gearbox, J is the equivalent moment of inertia, M t is the equivalent modal mass of the tower, C t is the structural damping of the tower, K t is the bending stiffness of the tower, F a is the aerodynamic thrust, i.e., the axial force of the wind wheel acting on the top end of the tower, F1 is the wave load force equivalent to the top end of the tower, F2 is the aerodynamic force equivalent to the top of the tower directly from the wind acting on the tower, T ac is the time constant of the variable pitch actuator, β * is the output instruction value of the variable pitch controller.

[0028] Through the above technical solution, the embodiment of the application can accurately present the complex dynamic characteristics of the actual operation of the wind turbine, cover the key degrees of freedom and mutual coupling relationship, accurately simulate the nonlinear factors such as aerodynamic thrust and torque, and is beneficial to optimizing power tracking and improving power generation efficiency.

[0029] Optionally, in an embodiment of the application, the calculation formula of the additional variable pitch rate is:

[0030]

[0031] wherein, is the output additional variable pitch rate of the i-th proportional resonant controller, ω ci is the shear frequency input to the i-th proportional resonant controller, ω i is the center frequency input to the i-th proportional resonant controller, x t is the top displacement of the tower, K Pi is the proportional control gain, K Ri is the resonant control gain.

[0032] Through the above technical solution, the additional variable pitch rate calculation formula of the embodiment of the application is derived based on the tower front and rear vibration system characteristics and related analysis, and is proportional to the tower front and rear vibration acceleration, so that the additional variable pitch rate can be conveniently calculated by monitoring the vibration acceleration, thereby providing a direct and effective means for realizing accurate vibration control.

[0033] The third aspect embodiment of the application provides an electronic device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the program to realize the tower front and rear vibration damping method of the large wind turbine as described in the above embodiments.

[0034] The fourth aspect of the present application provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the large wind turbine tower front and rear vibration resistance adding method.

[0035] The fifth aspect of the present application provides a computer program product, which includes a computer program, and the computer program is executed to implement the large wind turbine tower front and rear vibration resistance adding method.

[0036] The embodiments of the present application can obtain the tower vibration peak frequency by establishing a nonlinear model to generate an additional variable pitch rate, which can suppress tower vibration, enhance stability, reduce fatigue load, reduce operation and maintenance cost, and prolong service life; the method of adding the additional variable pitch rate to the reference variable pitch rate is simple and effective to integrate different variable pitch rates, adapt to working conditions, and improve stability; the tower vibration frequency related parameters are input into the proportional resonant controller to output the additional variable pitch rate, which can improve the resistance effect; the wind turbine operation characteristics can be accurately presented to facilitate power tracking optimization; and the relationship between the additional variable pitch rate calculation formula and the vibration acceleration provides an effective means for accurate vibration control.

[0037] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0038] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0039] Figure 1 A flowchart of a large wind turbine tower front and rear vibration resistance adding method according to an embodiment of the present application is provided;

[0040] Figure 2 A control principle schematic diagram of a large wind turbine tower front and rear vibration resistance adding method according to an embodiment of the present application is provided;

[0041] Figure 3 A structural schematic diagram of a large wind turbine tower front and rear vibration resistance adding device according to an embodiment of the present application is provided;

[0042] Figure 4 A structural example diagram of an electronic device according to an embodiment of the present application is provided. DETAILED DESCRIPTION

[0043] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0044] The tower front and rear vibration damping method and device of a large wind turbine generator set of embodiments of the present application are described below with reference to the drawings. In view of the problems in the related art mentioned above, the sensor performance is reduced due to the harsh environment, resulting in inaccurate transmission data, and the system complexity is high but the algorithm adaptability is insufficient, so it is not easy to implement, the cost is high, etc. The present application provides a tower front and rear vibration damping method of a large wind turbine generator set. In the method, the tower vibration peak frequency can be obtained based on the established nonlinear model and the equivalent damping analysis result, and then an additional variable pitch rate is generated for vibration damping, effectively suppressing tower front and rear vibration, enhancing tower stability, reducing fatigue load caused by vibration, thereby reducing the operation and maintenance cost of the wind turbine generator set and prolonging its service life. Moreover, it is not necessary to change the mechanical structure of the wind turbine generator set and the electromagnetic torque controller, only an additional pitch angle command is needed, and without the specific parameters of the wind turbine, the controller can be designed to suppress multiple vibration modes according to the tower vibration phenomenon. Only one nonlinear controller can effectively control the whole wind speed working area, so that the controller design is simple and efficient, the dynamic performance is good, thereby improving the accuracy, economy and engineering practicability of the control. Thus, the problems in the related art that the sensor performance is reduced due to the harsh environment, resulting in inaccurate transmission data, and the system complexity is high but the algorithm adaptability is insufficient, so it is not easy to implement, the cost is high, etc. are solved.

[0045] Specifically, Figure 1 A flowchart of a tower front and rear vibration damping method of a large wind turbine generator set provided by embodiments of the present application is shown.

[0046] As Figure 1 shown, the tower front and rear vibration damping method of a large wind turbine generator set includes the following steps:

[0047] In step S101, a nonlinear model of a wind turbine generator set considering tower front and rear vibration is established based on the pre-established nonlinear model, and the equivalent damping analysis result of the second-order dynamic equation of tower front and rear vibration is obtained.

[0048] It can be understood that the simplified nonlinear model of the wind turbine generator set includes two degrees of freedom, i.e. the front and rear vibration modes of the tower and the rotation motion of the wind wheel. The control input of the wind turbine generator set is the unified pitch angle β, and the disturbance input is the effective wind speed v0 of the wind wheel. For the high wind speed area, the electromagnetic torque T e of the generator is the rated value, so it is not considered as a control input here. The output of the system includes the wind wheel speed Ω r and the tower top speed Assume that they can be measured directly.

[0049] Optionally, in an embodiment of the present application, the expression of the wind turbine to establish a nonlinear model includes:

[0050]

[0051] Equation (1) is a first-order dynamic model of the transmission system, Ω r is the rotor speed, T a is the aerodynamic torque, T e is the generator electromagnetic torque, x t is the tower top displacement, β is the unified pitch angle, v0 is the effective wind speed of the rotor, G is the gear ratio of the gearbox, and J is the equivalent moment of inertia. Specifically, the equivalent moment of inertia J is the sum of the moments of inertia of the hub, blades and generator, i.e.: h b g

[0052] J = J h + 3J b + J g · G 2 (1.1)

[0053] Optionally, in an embodiment of the present application, the expression of the wind turbine to establish a nonlinear model includes:

[0054]

[0055] Equation (2) is a second-order dynamic equation of the tower front-back vibration system, M t is the equivalent modal mass of the tower, C t is the structural damping of the tower, K t is the bending stiffness of the tower, F a is the aerodynamic thrust, i.e. the axial force of the rotor acting on the top of the tower, F1 is the wave load force equivalent to the tower top, and F2 is the aerodynamic force equivalent to the tower top from the wind directly acting on the tower.

[0056] In actual implementation, the tower bears forces from three parts, i.e. the axial force of the rotor acting on the top of the tower, the aerodynamic force of the wind directly acting on the tower, and the wave force of the sea wave acting on the tower bottom. When analyzing the forces, the tower front-back vibration system can be simplified as a cantilever beam model, i.e. equation (2).

[0057] Specifically, the calculation methods of M t , C t , and K t are as follows:

[0058] M t = 0.25m​​​t +m n +m h +3m b (2.1)

[0059] C t = 4πM t d s f0 (2.2)

[0060] K t = M t (2πf0) 2 (2.3)

[0061] wherein m t is the mass of the tower, m n is the mass of the nacelle, m h is the mass of the hub, m b is the mass of the blades, d s is the structural damping ratio of the tower, and f0is the natural frequency of the tower fore-aft vibration.

[0062] Optionally, in an embodiment of the present application, the expression of the wind turbine for establishing the nonlinear model comprises:

[0063]

[0064] Equation (3) is a dynamic model of the variable pitch actuator, which is equivalent to a first-order inertia link. Wherein, T ac is the time constant of the variable pitch actuator, and β * is the output command value of the variable pitch controller.

[0065] It can be understood that the nonlinearity of the wind turbine model is mainly reflected in the expressions of the aerodynamic torque and the aerodynamic thrust:

[0066]

[0067] wherein ρ is the air density, R is the radius of the wind wheel, C q is the aerodynamic torque coefficient, is the relative wind speed considering the influence of the tower fore-aft vibration, C t is the aerodynamic thrust coefficient, and the aerodynamic torque and the aerodynamic thrust are both non-affine nonlinear functions of λ and β. λ is the tip speed ratio, which is expressed as:

[0068]

[0069] The embodiment of the application can establish a nonlinear model of a wind turbine considering front and back vibrations of a tower, which can accurately describe the characteristics of a transmission system, and the second-order dynamic equation (formula 2) of the front and back vibrations of the tower considers various forces borne by the tower, and comprehensive stress analysis is helpful to accurately simulate the vibration of the tower; in the model, a reasonable calculation method is given for equivalent moment of inertia, equivalent modal mass of the tower, structural damping and bending stiffness and other parameters, and these calculations are based on actual parameters such as mass, structural damping ratio and natural frequency of each part of the wind turbine, so that the model can be closer to the actual physical characteristics of the wind turbine, thereby improving the accuracy of the model; the control input and disturbance input of the wind turbine are clearly defined, and the output is determined, and the dynamic model (formula 3) of the variable pitch actuator is equivalent to a first-order inertia link, and such clear definition of the relationship between the control and the output is helpful to better design and optimize the control strategy of the wind turbine; the nonlinear characteristics of the wind turbine model are accurately pointed out in the expressions of the aerodynamic torque and the aerodynamic thrust (formula 4, formula 5), and the influence of the tip speed ratio (formula 6) is considered, and such embodiment of the nonlinear characteristics can more truly reflect the complex situation of the wind turbine in actual operation, which is conducive to in-depth research and optimization of the performance of the wind turbine.

[0070] In step S102, the tower vibration peak frequency under different rotational speeds is obtained according to the equivalent damping analysis result.

[0071] It can be understood that the equivalent damping analysis result is related information about how to equivalently increase the damping of the tower to suppress vibration, which is obtained by a series of analysis and calculation based on the second-order dynamic equation of the front and back vibrations of the tower in the nonlinear model of the wind turbine considering the front and back vibrations of the tower. The tower vibration peak frequency refers to the frequency corresponding to the maximum vibration amplitude of the tower in the process of front and back vibrations.

[0072] In actual execution, the influence of the change of each parameter on the vibration characteristics of the tower under different rotational speeds is analyzed. For example, as can be seen from formula (4) and formula (6), the change of the rotational speed will affect the aerodynamic torque, and the tip speed ratio is related to the rotational speed, thereby changing the force acting on the tower and affecting the vibration response of the tower.

[0073] In some cases, the modal equation of the front and back vibration system of the tower can be solved, and the natural frequency and mode shape of the system are determined by calculating the eigenvalues and eigenvectors of the system. Under different rotational speed conditions, the natural frequency will also change due to the change of the system parameters. By comparing the modal analysis results under different rotational speeds, the peak frequency of the tower vibration can be identified. For example, when the rotational speed increases, the vibration response of a certain modal of the tower may be enhanced due to the change of factors such as aerodynamic load, and the vibration amplitude near the corresponding natural frequency increases, thereby determining the vibration peak frequency under the rotational speed.

[0074] In other cases, the vibration of the tower can be monitored in real time during the actual operation of the wind turbine generator by sensors installed on the tower to obtain vibration data at different rotational speeds. The monitoring data is analyzed by frequency spectrum analysis to observe the energy distribution of the vibration signal at different frequency components. The frequency band with relatively concentrated vibration energy can correspond to the peak frequency of the tower vibration. The accurate tower vibration peak frequency at different rotational speeds is verified and determined in combination with the theoretical analysis results. For example, at high rotational speed, it is found through frequency spectrum analysis that the vibration amplitude at a certain frequency is significantly higher than that at other frequencies, and it is consistent with the vibration frequency that can occur at this rotational speed in theoretical calculation, so that the frequency is determined as the tower vibration peak frequency at high rotational speed.

[0075] Further, according to the tower dynamic model of formula (2), if a damping force command value F t is superimposed on the basis of the force on the right side of the equation, then the front and rear vibration equations of the tower can be expressed as:

[0076]

[0077] The system is controlled by using a proportional controller, and the damping force command value F t satisfies:

[0078]

[0079] where ΔC t is the proportional coefficient of the proportional controller. After substituting formula (8) into formula (7), the following is obtained:

[0080]

[0081] It can be seen that the proportional feedback control can effectively increase the damping of the front and rear vibrations of the tower, and realize the tower damping. Different equivalent damping values will change the vibration characteristics of the system. Larger equivalent damping can suppress the vibration at certain frequencies, and make the vibration energy transfer to other frequencies. When analyzing the tower vibration peak frequency at different rotational speeds, the influence of the change of the equivalent damping on the vibration frequency and amplitude needs to be considered. For example, after increasing the equivalent damping at a certain rotational speed, it is observed that the vibration peak at a certain higher frequency is reduced, and the vibration amplitude at another frequency is relatively increased, so that the new vibration peak frequency is determined.

[0082] The embodiments of the present application can consider various influencing factors, such as the change of rotational speed which affects the aerodynamic torque and then changes the force acting on the tower, thereby affecting the vibration response; the influence of the change of the equivalent damping on the vibration frequency and amplitude, and different equivalent damping values will change the vibration characteristics of the system, which is helpful to more comprehensively understand the tower vibration and make the analysis results closer to the actual situation.

[0083] In step S103, an additional pitch rate for tower damping is generated according to the tower vibration peak frequency, so as to perform vibration damping by using the additional pitch rate.

[0084] It can be understood that the additional pitch rate is a pitch rate instruction additionally applied to suppress the front and rear tower vibration, for example, when it is detected that the tower vibrates greatly at a certain vibration peak frequency, a suitable additional pitch rate is calculated according to a corresponding control strategy, so that the blades adjust the pitch angle at the rate, change the aerodynamic performance of the wind wheel, and then suppress the vibration of the tower at the frequency. The vibration damping refers to the process of taking measures to increase the damping of the tower vibration system, so as to reduce the amplitude of the tower vibration.

[0085] Optionally, in an embodiment of the present application, the additional pitch rate for tower damping is generated according to the tower vibration peak frequency, comprising: inputting at least one center frequency and at least one shear frequency of the tower vibration peak frequency into a preset proportional resonance controller respectively, so as to output the additional pitch rate.

[0086] In actual execution process, if the damping force instruction value F t is regarded as an additional aerodynamic thrust, it can be known that F t is a function about wind speed, rotating speed and pitch angle, and has:

[0087]

[0088] From equation (8) and equation (10), the additional pitch angle β t can be obtained:

[0089]

[0090] Taking derivative of both sides of equation (11), the additional pitch rate can be obtained:

[0091]

[0092] It can be known that the additional pitch rate is in proportional relationship with the front and rear tower vibration acceleration , and can be obtained by : and input as a control quantity into the wind turbine system. By analyzing the characteristics of the front and rear tower vibration system, the n peak frequencies ω1, ω2, …, ω n of the front and rear tower vibration at different wind speeds and the shear frequencies ω c1 , ω c2 , …, ω cn used by the damping controller can be obtained. As shown in FIG. 6, the front and rear tower vibration acceleration is input into a parallel proportional resonance controller, and the additional pitch rate can be extracted. The individual frequency components that have a major influence on the vibration are identified, and an additional pitch rate is derived that has a targeted damping effect on each component That is,

[0093]

[0094] where, ω is the output additional pitch rate of the i-th PR controller, ω ci ω is the shear frequency input to the i-th PR controller, ω i ω is the center frequency input to the i-th PR controller, ω t K is the tower top displacement, K Pi K is the proportional control gain, K Ri K is the resonant control gain.

[0095] Optionally, in one embodiment of the present application, the vibration damping using the additional pitch rate includes: adding the additional pitch rate to a base pitch rate for controlling the rotational speed to generate a total pitch rate command value.

[0096] Specifically, the total pitch rate input to the wind turbine pitch controller is

[0097]

[0098] where, K is the base pitch rate for controlling the rotational speed, output by the unified pitch controller.

[0099] ​The embodiment of the application generates an additional pitch rate by analyzing the tower vibration peak frequency to suppress tower vibration, calculates the additional pitch rate considering multiple frequencies, ensures accuracy and conforms to actual working conditions according to the relationship with variables such as vibration acceleration, and the additional pitch rate can be combined with a reference pitch rate to generate a total pitch rate instruction value, integrated into the overall control strategy, effectively balancing tower vibration suppression and speed control, and comprehensively and specifically controlling wind turbine tower vibration. According to the tower front and rear vibration damping method of the large wind turbine proposed in the embodiment of the application, the tower vibration peak frequency can be obtained based on the established nonlinear model and equivalent damping analysis results, and then the additional pitch rate is generated for vibration damping, effectively suppressing tower front and rear vibration, enhancing tower stability, reducing fatigue load caused by vibration, thereby reducing the operation and maintenance cost of the wind turbine and prolonging its service life, and without changing the mechanical structure of the wind turbine and the electromagnetic torque controller, only the pitch angle instruction is added, and without the specific parameters of the wind turbine, the controller can be designed according to the tower vibration phenomenon to suppress multiple vibration modes, and only one nonlinear controller can be designed to effectively control the full wind speed working area, so that the controller design is simple and efficient, the dynamic performance is good, and the accuracy, economy and engineering practicability of the control are improved.

[0100] Secondly, the tower front and rear vibration damping device of the large wind turbine according to the embodiment of the application is described with reference to the accompanying drawings.

[0101] Figure 3 is a block schematic diagram of the tower front and rear vibration damping device of the large wind turbine according to the embodiment of the application.

[0102] As shown in Figure 3 , the tower front and rear vibration damping device 10 of the large wind turbine comprises a first acquisition module 100, a second acquisition module 200 and a vibration damping module 300.

[0103] Specifically, the first acquisition module 100 is configured to establish a nonlinear model based on a wind turbine considering tower front and rear vibration, and obtain equivalent damping analysis results of a second-order dynamic equation of tower front and rear vibration.

[0104] The second acquisition module 200 is configured to obtain tower vibration peak frequencies at different speeds according to the equivalent damping analysis results.

[0105] The vibration damping module 300 is configured to generate an additional pitch rate for tower damping according to the tower vibration peak frequency, so as to use the additional pitch rate for vibration damping.

[0106] Optionally, in an embodiment of the application, the vibration damping module 300 comprises a generation unit configured to add the additional pitch rate to a reference pitch rate for controlling the speed to generate a total pitch rate instruction value.

[0107] Optionally, in an embodiment of the present application, the vibration plus resistance module 300 comprises an output unit configured to input at least one center frequency and at least one shear frequency of the tower vibration peak frequency into a preset proportional resonance controller respectively to output an additional pitch rate.

[0108] Optionally, in an embodiment of the present application, the expression of the wind turbine for establishing a nonlinear model is as follows:

[0109]

[0110] wherein, Ω r is the wind wheel speed, T a is the aerodynamic torque, T e is the generator electromagnetic torque, x t is the tower top displacement, β is the unified pitch angle, v0 is the effective wind speed of the wind wheel, G is the gear ratio of the gearbox, J is the equivalent moment of inertia, M t is the equivalent modal mass of the tower, C t is the structural damping of the tower, K t is the bending stiffness of the tower, F a is the aerodynamic thrust, i.e., the axial force of the wind wheel acting on the top of the tower, F1 is the wave load force equivalent to the top of the tower, F2 is the aerodynamic force equivalent to the top of the tower directly from the wind acting on the tower, T ac is the time constant of the pitch actuator, β * is the output instruction value of the pitch controller.

[0111] Optionally, in an embodiment of the present application, the calculation formula of the additional pitch rate is as follows:

[0112]

[0113] wherein, is the output additional pitch rate of the i-th proportional resonance controller, ω ci is the shear frequency input into the i-th proportional resonance controller, ω i is the center frequency input into the i-th proportional resonance controller, x t is the tower top displacement, K Pi is the proportional control gain, K Ri is the resonance control gain.

[0114] It should be noted that the aforementioned explanation and description of the embodiment of the tower front and rear vibration plus resistance method of the large wind turbine also applies to the tower front and rear vibration plus resistance device of the large wind turbine of this embodiment, which will not be described here.

[0115] According to the large wind turbine tower front and rear vibration resistance device provided by the embodiment of the application, the tower vibration peak frequency can be obtained based on the established nonlinear model and the equivalent resistance analysis result, and then the additional variable pitch rate is generated to perform vibration resistance, so as to effectively suppress the tower front and rear vibration, enhance the tower stability, reduce the fatigue load caused by the vibration, thereby reducing the operation and maintenance cost of the wind turbine and prolonging the service life of the wind turbine, and without changing the mechanical structure of the wind turbine and the electromagnetic torque controller, only the pitch angle instruction is needed, and without the specific parameters of the wind turbine, the controller can be designed according to the tower vibration phenomenon to suppress multiple vibration modes, only one nonlinear controller can be designed to effectively control the full wind speed working area, so that the controller design is simple and efficient, the dynamic performance is good, and the accuracy, economy and engineering practicability of the control are improved.

[0116] Figure 4 The electronic device provided by the embodiment of the application is shown in the structural diagram. The electronic device can include:

[0117] The memory 401, the processor 402 and the computer program stored in the memory 401 and executable on the processor 402.

[0118] The processor 402 implements the large wind turbine tower front and rear vibration resistance method provided in the above embodiment when executing the program.

[0119] Further, the electronic device further includes:

[0120] The communication interface 403 is used for communication between the memory 401 and the processor 402.

[0121] The memory 401 is used to store the computer program executable on the processor 402.

[0122] The memory 401 can include a high-speed RAM memory, and can also include a non-volatile memory, for example, at least one magnetic disk memory.

[0123] If the memory 401, the processor 402 and the communication interface 403 are implemented independently, the communication interface 403, the memory 401 and the processor 402 can be connected with each other through a bus and complete communication between each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For convenience of representation, Figure 4 Only one thick line is used to represent the bus in the figure, but it does not mean that there is only one bus or only one type of bus.

[0124] Optionally, in a specific implementation, if the memory 401, the processor 402 and the communication interface 403 are integrated on a chip, the memory 401, the processor 402 and the communication interface 403 can complete communication between each other through an internal interface.

[0125] The processor 402 can be a Central Processing Unit (CPU), or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0126] The embodiments of the present application also provide a computer readable storage medium, which has a computer program stored thereon, and the program is executed by a processor to implement the method for adding resistance to front and back vibrations of a tower of a large wind turbine generator as described above.

[0127] The embodiments of the present application also provide a computer program product, which includes a computer program, and the computer program is executed to implement the method for adding resistance to front and back vibrations of a tower of a large wind turbine generator as described above.

[0128] In the description of the application, reference to "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, the described specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. In addition, the usage of "N" means at least two, for example, two, three or the like, unless explicitly stated otherwise.

[0129] Furthermore, the terms "first", "second", or the like, are used merely as a designation of certain elements or features, and do not imply or connote relative importance or a specific order of categorization thereof. Accordingly, features described as "first" or "second" can be explicitly or implicitly included in at least one of the features. In the description of the application, the meaning of "N" is at least two, for example, two, three, etc., unless explicitly specified otherwise.

[0130] Any process or method descriptions or blocks in flow charts or otherwise described herein represent embodiments which can be managed as one or more modules, segments, or portions of code which include one or more executable instructions for implementing specific logic functions or steps, and alternate implementations are possible. In some embodiments, the processes and methods described can be executed by one or more apparatuses or devices, either directly or after conversion to another language.

[0131] The logic and / or steps represented in the flowcharts and / or described herein, for example, can be considered as a sequence of executable instructions stored in a computer readable medium, which can be executed by an instruction execution system, apparatus or device, such as a computer-based system, a processor-based system, or other system that can fetch the instructions from the instruction execution system, apparatus or device and execute the instructions, or a combination of the above. For the purposes of this specification, a "computer readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus or device. The computer readable medium can be a computer readable storage medium or a computer readable signal medium. The computer readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a propagation medium. The computer readable signal medium can include, but is not limited to, a computer readable medium that facilitates transfer of the program from one place to another. A specific example of a computer readable medium is a non-transitory computer-readable storage medium. A specific example of a computer readable signal medium is a source or destination of the computer readable medium. Another specific example of a computer readable signal medium is a computer readable signal travelling through space. Thus, a computer readable medium can take many forms of hardware to carry out the program for use by or in connection with the instruction execution system, apparatus or device.

[0132] It should be understood that aspects of the application can be implemented in hardware, software, firmware or a combination thereof. In the above embodiments, the N steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented in hardware and in another embodiment, the hardware can be implemented using any or a combination of the following technologies, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon an application of data signals, an application specific integrated circuit having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.

[0133] Those of skill in the art would understand that the steps of the methods carried out above can be carried out wholly or partly by a program instructing relevant hardware, and the program can be stored in a computer readable storage medium, and when executed, includes one or a combination of the steps of the method embodiments.

[0134] In addition, each of the functional units in the various embodiments of the present application can be integrated in one processing module, or each of the units can be physically present separately, or two or more units can be integrated in one module. The integrated module can be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer readable storage medium.

[0135] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for applying damping to the front and rear vibrations of a large wind turbine tower, characterized in that, Includes the following steps: A nonlinear model of a wind turbine considering the front and rear vibrations of the tower is established based on a pre-established model, and the equivalent drag analysis results of the second-order dynamic equation of the front and rear vibrations of the tower are obtained. The peak frequency of tower vibration at different rotational speeds was obtained based on the equivalent resistance analysis results. An additional pitch rate for tower dragging is generated based on the tower vibration peak frequency, so as to utilize the additional pitch rate for vibration dragging. The step of generating an additional pitch rate for tower drag based on the tower vibration peak frequency includes: At least one center frequency and at least one shear frequency of the tower vibration peak frequency are respectively input into a preset proportional resonant controller to output the additional pitch rate.

2. The method according to claim 1, characterized in that, The vibration damping using the additional pitch rate includes: The additional pitch rate is added to the reference pitch rate used to control the rotational speed to generate a total pitch rate command value.

3. The method according to claim 1, characterized in that, The expression for establishing the nonlinear model of the wind turbine is as follows: in, The wind turbine rotation speed, For aerodynamic torque, For the electromagnetic torque of the generator, For the displacement of the tower top, To standardize the pitch angle, The effective wind speed of the wind turbine. For the gearbox's transformation ratio, For the equivalent moment of inertia, For the equivalent modal mass of the tower, For the structural damping of the tower, For the bending stiffness of the tower, This is aerodynamic thrust, specifically the axial force exerted by the wind turbine on the top of the tower. This is equivalent to the wave load force applied to the top of the tower. To represent the aerodynamic force from the wind directly acting on the tower top, The time constant of the pitch actuator. This is the output command value of the pitch controller.

4. The method according to claim 3, characterized in that, The formula for calculating the additional pitch rate is: ， in, Add pitch rate to the output of the i-th proportional resonant controller. The input is the crossover frequency of the i-th proportional resonant controller. The input is the center frequency of the i-th proportional resonant controller. For the displacement of the tower top, For proportional control gain, This is the resonant control gain.

5. A vibration damping device for the tower of a large wind turbine, characterized in that, include: The first acquisition module is used to establish a nonlinear model of the wind turbine considering the front and rear vibrations of the tower based on a pre-established model, and to obtain the equivalent drag analysis results of the second-order dynamic equation of the front and rear vibrations of the tower. The second acquisition module is used to acquire the peak frequency of tower vibration at different rotational speeds based on the equivalent resistance analysis results. A vibration damping module is used to generate an additional pitch rate for damping the tower based on the peak frequency of the tower vibration, so as to use the additional pitch rate for vibration damping. The step of generating an additional pitch rate for tower drag based on the tower vibration peak frequency includes: At least one center frequency and at least one shear frequency of the tower vibration peak frequency are respectively input into a preset proportional resonant controller to output the additional pitch rate.

6. The apparatus according to claim 5, characterized in that, The vibration damping module includes: The generation unit is used to add the additional pitch rate to the reference pitch rate used to control the rotational speed to generate a total pitch rate command value.

7. An electronic device, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, the processor executing the program to implement the method for applying damping to the front and rear vibrations of a large wind turbine tower as described in any one of claims 1-4.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the method for applying damping to the front and rear vibrations of the tower of a large wind turbine as described in any one of claims 1-4.

9. A computer program product, comprising a computer program, characterized in that, The computer program is executed to implement the method for applying resistance to the front and rear vibrations of a large wind turbine tower as described in any one of claims 1-4.

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