Vibration type identification method, control method and device of wind turbine generator set

Abstract

Disclosed are a method for identifying the vibration type of a wind turbine generator set, a control method and a device. The method for identifying the vibration type of a wind turbine generator set comprises: obtaining an acceleration signal of a dominant direction of the wind turbine generator set; determining the frequency of the acceleration signal of the dominant direction; and identifying the vibration type of the wind turbine generator set according to the frequency of the acceleration signal and the tower natural frequency of the wind turbine generator set and the rotation frequency of the wind turbine generator set. Through the present disclosure, the problems of power generation loss caused by fault shutdown of the wind turbine generator set controlled by the acceleration amplitude in the prior art can be effectively solved.

Description

Technical Field

[0001] The present disclosure generally relates to the field of wind power generation technology, and more specifically, to a vibration type identification method, a control method and a device for a wind generator set. Background Art

[0002] The vibration protection of a wind turbine generator set (also called a unit) relies on an acceleration sensor installed on the top of the tower. The acceleration signal of the unit is detected by the acceleration sensor. When the amplitude of the acceleration signal reaches the fault threshold, the unit is immediately shut down to ensure the safety of the unit.

[0003] At present, a large number of wind turbines are installed in complex mountainous terrains and the impeller diameters of the wind turbines are relatively large. It is common for low-frequency vibrations such as the first-order tower and 3p speed to be rapidly excited under complex wind conditions. In the above situations, there is no need to perform a fault shutdown. However, in the prior art, as long as the amplitude of the acceleration signal reaches the fault threshold, the unit will report a fault and execute a fault shutdown. This results in power generation loss, an increase in the number of start-up and shutdown times of the unit under high wind conditions, and an increase in the workload of fault data analysis and processing. Summary of the invention

[0004] Embodiments of the present disclosure provide a method, a control method and a device for identifying the vibration type of a wind turbine generator set. The method, the control method and the device for identifying the vibration type of a wind turbine generator set can effectively solve the problem of power generation loss caused by controlling the shutdown of the unit due to a fault according to the acceleration amplitude in the prior art.

[0005] In a general aspect, a method for identifying the vibration type of a wind turbine is provided, comprising: acquiring an acceleration signal in a dominant direction of the wind turbine; determining the frequency of the acceleration signal in the dominant direction; and identifying the vibration type of the wind turbine based on the frequency of the acceleration signal and the tower natural frequency of the wind turbine and the rotational frequency of the wind turbine.

[0006] Optionally, identifying the vibration type of the wind turbine generator set based on the frequency of the acceleration signal and the tower natural frequency and the rotational frequency of the wind turbine generator set includes: determining whether the difference between the frequency of the acceleration signal and the tower natural frequency or the rotational frequency of the wind turbine generator set is within a predetermined range; in response to the difference being within the predetermined range, determining the vibration type to be an inherent vibration type corresponding to the tower natural frequency or the rotational frequency; in response to the difference exceeding the predetermined range, determining the vibration type to be a non-inherent vibration type.

[0007] Optionally, in response to the difference being within a predetermined range, determining that the vibration type of the wind turbine generator set is a natural vibration type corresponding to the natural frequency or rotational frequency of the tower includes: when a status flag of the wind turbine generator set is greater than or equal to a first predetermined value, a current rotational speed of the wind turbine generator set is greater than or equal to a second predetermined value, the grid-connected time of the wind turbine generator set does not exceed the first predetermined time, or the wind turbine generator set is not connected to the grid, in response to the difference being within a predetermined range, determining that the vibration type of the wind turbine generator set is startup process vibration.

[0008] Optionally, in response to the difference being within a predetermined range, determining that the vibration type of the wind turbine is a natural vibration type corresponding to the natural frequency or rotational frequency of the tower includes: the average speed or instantaneous speed of the wind turbine is less than the minimum operating speed within a second predetermined time, the average grid-side power or instantaneous power within the second predetermined time is less than a third predetermined value, the grid-connected time of the wind turbine exceeds the first predetermined time, and the wind turbine is in a fully propeller-opening state. In response to the difference being within a predetermined range, determining that the vibration type of the wind turbine is a low wind speed drop resonance.

[0009] Optionally, the step of determining the frequency of the acceleration signal in the dominant direction includes: marking the acceleration signal in the dominant direction in a predetermined marking manner; and determining the frequency of the acceleration signal in the dominant direction based on the number of data between two marking points of the marked acceleration signal and a data sampling period.

[0010] Optionally, the predetermined marking method includes a zero-crossing marking method, a peak marking method, and a trough marking method.

[0011] Optionally, before marking the acceleration signal of the dominant direction in a predetermined marking manner, the method further includes: performing low-pass filtering on the acceleration signal of the dominant direction.

[0012] In another general aspect, a control method for a wind turbine generator set comprises: identifying a vibration type of the wind turbine generator set based on any of the above-mentioned methods for identifying a vibration type of the wind turbine generator set; determining a target control mode of the wind turbine generator set according to the vibration type and a vibration fault threshold of the wind turbine generator set; and controlling the wind turbine generator set using the target control mode.

[0013] Optionally, determining the target control mode of the wind turbine generator set includes: when the vibration type is the inherent vibration type of the wind turbine generator set, determining the target control mode of the wind turbine generator set according to the relationship between the amplitude of the acceleration signal and the vibration fault threshold; when the vibration type is the non-inherent vibration type of the wind turbine generator set, determining the target control mode of the wind turbine generator set to control the wind turbine generator set to shut down.

[0014] Optionally, based on the relationship between the amplitude of the acceleration signal and the vibration fault threshold, determining the target control mode of the wind turbine generator set includes: when the number of times the amplitude of the acceleration signal reaches the vibration fault threshold does not exceed the predetermined number of times within a third predetermined time, determining the target control mode of the wind turbine generator set based on the power of the acceleration signal; when the number of times the amplitude of the acceleration signal reaches the vibration fault threshold exceeds the predetermined number of times within the third predetermined time, determining the target control mode of the wind turbine generator set to control the wind turbine generator set to shut down.

[0015] Optionally, determining the target control mode of the wind turbine generator set based on the power of the acceleration signal includes: when the power of the acceleration signal exceeds a predetermined power value, determining the target control mode of the wind turbine generator set to increase the minimum operating pitch angle of the wind turbine generator set and / or limit the power to reduce the load; when the power of the acceleration signal does not exceed the predetermined power value, determining the target control mode of the wind turbine generator set to control the wind turbine generator set to shut down.

[0016] Optionally, reducing the load by increasing the minimum operating pitch angle and / or power limit of the wind turbine generator set includes: increasing the minimum operating pitch angle and / or power limit for a preset time, and after the preset time, restoring the original minimum operating pitch angle and power limit.

[0017] Optionally, it also includes: in the process of increasing the minimum operating pitch angle and / or limiting the power to reduce the load, when the amplitude of the acceleration signal reaches a stop load reduction threshold, controlling the wind turbine generator set to shut down, wherein the stop load reduction threshold is greater than the vibration fault threshold.

[0018] Optionally, determining the target control method of the wind turbine generator set based on the vibration type and the vibration fault threshold of the wind turbine generator set includes: when the vibration type is the inherent vibration type of the wind turbine generator set and the vibration amplitude of the acceleration within a fourth predetermined time exceeds the first preset threshold for a predetermined number of times, determining the target control method to be to reduce the amplitude of the acceleration signal by limiting power, wherein the first preset threshold is less than the vibration fault threshold.

[0019] Optionally, reducing the amplitude of the acceleration signal by limiting the power includes: cyclically adjusting the power limit to reduce the amplitude of the acceleration signal until the amplitude of the acceleration signal reaches a second preset threshold, wherein the second preset threshold is less than the first preset threshold.

[0020] In another general aspect, a vibration type identification device for a wind turbine is provided, comprising: a first acquisition module for acquiring an acceleration signal in a dominant direction of the wind turbine; a first determination module for determining the frequency of the acceleration signal in the dominant direction; and a first identification module for identifying the vibration type of the wind turbine based on the frequency of the acceleration signal and the natural frequency of the tower and the rotational frequency of the wind turbine.

[0021] Optionally, the first identification module is also used to determine whether the difference between the frequency of the acceleration signal and the tower natural frequency or the rotational frequency of the wind turbine is within a predetermined range; in response to the difference being within the predetermined range, determining the vibration type as an inherent vibration type corresponding to the tower natural frequency or the rotational frequency; in response to the difference exceeding the predetermined range, determining the vibration type as a non-inherent vibration type.

[0022] Optionally, the first identification module is also used to determine that the vibration type of the wind turbine is startup process vibration in response to a difference being within a predetermined range when the status flag of the wind turbine is greater than or equal to a first predetermined value, the current speed of the wind turbine is greater than or equal to a second predetermined value, the grid-connected time of the wind turbine does not exceed the first predetermined time, or the wind turbine is not connected to the grid.

[0023] Optionally, the first identification module is also used to determine that the vibration type of the wind turbine is low wind speed drop resonance in response to the difference being within a predetermined range when the average speed or instantaneous speed of the wind turbine is less than the minimum operating speed within a second predetermined time, the average grid-side power or instantaneous power within the second predetermined time is less than a third predetermined value, the grid-connected time of the wind turbine exceeds the first predetermined time, and the wind turbine is in a fully propeller-opening state.

[0024] Optionally, the first determination module is further used to mark the acceleration signal of the dominant direction in a predetermined marking manner; and determine the frequency of the acceleration signal of the dominant direction according to the number of data between two marking points of the marked acceleration signal and the data sampling period.

[0025] Optionally, the predetermined marking method includes a zero-crossing marking method, a peak marking method, and a trough marking method.

[0026] Optionally, the first determination module is further configured to perform low-pass filtering on the acceleration signal in the dominant direction before marking the acceleration signal in the dominant direction in a predetermined marking manner.

[0027] In another general aspect, a control device for a wind turbine generator set is provided, comprising: a second identification module, used for the above-mentioned vibration type identification device of the wind turbine generator set to identify the vibration type of the wind turbine generator set; a second determination module, used to determine a target control method of the wind turbine generator set according to the vibration type and the vibration fault threshold of the wind turbine generator set; and a control module, used to control the wind turbine generator set by applying the target control method.

[0028] Optionally, the second determination module is also used to determine the target control mode of the wind turbine generator set according to the relationship between the amplitude of the acceleration signal and the vibration fault threshold when the vibration type is the inherent vibration type of the wind turbine generator set; when the vibration type is the non-inherent vibration type of the wind turbine generator set, determine the target control mode of the wind turbine generator set to control the wind turbine generator set to shut down.

[0029] Optionally, the second determination module is also used to determine the target control mode of the wind turbine generator set according to the power of the acceleration signal when the number of times the amplitude of the acceleration signal reaches the vibration fault threshold within the third predetermined time does not exceed the predetermined number of times; and to determine the target control mode of the wind turbine generator set to control the wind turbine generator set to shut down when the number of times the amplitude of the acceleration signal reaches the vibration fault threshold within the third predetermined time exceeds the predetermined number of times.

[0030] Optionally, the second determination module is also used to determine the target control mode of the wind turbine to increase the minimum operating pitch angle of the wind turbine and / or limit the power to reduce the load when the power of the acceleration signal exceeds a predetermined power value; when the power of the acceleration signal does not exceed the predetermined power value, determine the target control mode of the wind turbine to control the wind turbine to shut down.

[0031] Optionally, the second determining module is further configured to increase the minimum operating pitch angle and / or the power limit to a preset time, and restore the original minimum operating pitch angle and power limit after the preset time.

[0032] Optionally, the second determination module is further used to control the wind turbine generator set to shut down when the amplitude of the acceleration signal reaches a stop load reduction threshold during the process of increasing the minimum operating pitch angle and / or limiting the power to reduce the load, wherein the stop load reduction threshold is greater than the vibration fault threshold.

[0033] Optionally, the second determination module is also used to determine that the target control method is to reduce the amplitude of the acceleration signal by limiting power when the vibration type is the inherent vibration type of the wind turbine generator set and the vibration amplitude of the acceleration within a fourth predetermined time exceeds the first preset threshold for a predetermined number of times, wherein the first preset threshold is less than the vibration fault threshold.

[0034] Optionally, the second determination module is further configured to cyclically adjust the power limit to reduce the amplitude of the acceleration signal until the amplitude of the acceleration signal reaches a second preset threshold, wherein the second preset threshold is smaller than the first preset threshold.

[0035] In another general aspect, a computer-readable storage medium storing instructions is provided, wherein when the instructions are executed by at least one computing device, the at least one computing device is prompted to execute any of the above-mentioned methods for identifying a vibration type of a wind turbine generator set or methods for controlling a wind turbine generator set.

[0036] In another general aspect, a system is provided that includes at least one computing device and at least one storage device storing instructions, wherein the instructions, when executed by the at least one computing device, cause the at least one computing device to execute any of the wind turbine generator set vibration type identification methods or wind turbine generator set control methods described above.

[0037] According to the vibration type identification method, control method and device of the wind turbine generator set of the embodiment of the present disclosure, the acceleration signal of the dominant direction of the wind turbine generator set is obtained; the frequency of the acceleration signal of the dominant direction is determined; and the vibration type of the wind turbine generator set is identified according to the frequency of the acceleration signal and the tower natural frequency of the wind turbine generator set and the rotational frequency of the wind turbine generator set. The present disclosure conducts a comprehensive analysis of the frequency of the acceleration signal of the dominant direction of the wind turbine generator set, the tower natural frequency of the wind turbine generator set and the rotational frequency of the wind turbine generator set, and can effectively identify the vibration type of the wind turbine generator set, so that the wind turbine generator set can be controlled accordingly according to the identified vibration type, and no longer relies solely on the acceleration amplitude to control the unit to shut down due to faults. Therefore, through the present disclosure, the problem of power generation loss caused by the fault shutdown of the unit controlled by the acceleration amplitude in the prior art can be effectively solved.

[0038] Additional aspects and / or advantages of the present general inventive concept will be set forth in part in the following description and in part will be apparent from the description or may be learned through practice of the present general inventive concept. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and other objects and features of the embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings showing the embodiments, in which:

[0040] Figure 1 is a flow chart showing a method for identifying a vibration type of a wind turbine generator set according to an embodiment of the present disclosure;

[0041] Figure 2 is a schematic diagram showing the calculation of the acceleration period and frequency cutting in the X direction of an embodiment of the present disclosure;

[0042] Figure 3 is a flow chart showing an X-axis instantaneous rotation frequency vibration identification method according to an embodiment of the present disclosure;

[0043] Figure 4 is a flow chart showing a Y-axis instantaneous rotation frequency vibration identification method according to an embodiment of the present disclosure;

[0044] Figure 5 is a flow chart showing an X-axis instantaneous tower frequency vibration identification method according to an embodiment of the present disclosure;

[0045] Figure 6 is a flow chart showing a Y-axis instantaneous tower frequency vibration identification method according to an embodiment of the present disclosure;

[0046] Figure 7 is a flow chart showing a method for identifying vibration during a startup process according to an embodiment of the present disclosure;

[0047] Figure 8 is a flow chart showing a method for identifying a resonance of a small wind speed drop according to an embodiment of the present disclosure;

[0048] Fig. 9 is a flow chart showing the vibration dominant direction determination according to an embodiment of the present disclosure;

[0049] Fig.10 is a flow chart showing a control method of a wind turbine generator set according to an embodiment of the present disclosure;

[0050] Fig.11 is a flow chart showing a 3p vibration closed-loop control scheme for the X-axis speed according to an embodiment of the present disclosure;

[0051] Fig.12 is a flow chart showing the overall control flow of an embodiment of the present disclosure;

[0052] Fig.13 is a block diagram showing a vibration type identification device for a wind turbine generator set disclosed in the present invention;

[0053] Fig.14 is a block diagram showing a control device of a wind turbine generator system according to the present disclosure. DETAILED DESCRIPTION

[0054] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be clear. For example, the order of operations described herein is only an example and is not limited to those orders set forth herein, but can be changed as will be clear after understanding the disclosure of the present application, except for operations that must occur in a specific order. In addition, for greater clarity and simplicity, the description of features known in the art may be omitted.

[0055] The features described herein can be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided to illustrate only some of the many possible ways to implement the methods, devices, and / or systems described herein, which will be clear after understanding the disclosure of the present application.

[0056] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more.

[0057] Although terms such as "first", "second", and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions should not be limited by these terms. Instead, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, first component, first region, first layer, or first portion referred to in the examples may also be referred to as the second member, second component, second region, second layer, or second portion.

[0058] In the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, or “coupled to” another element, the element may be directly “on”, “connected to”, or “coupled to” another element, or one or more other elements may be present therebetween. Conversely, when an element is described as being “directly on”, “directly connected to”, or “directly coupled to” another element, there may be no other elements present therebetween.

[0059] The terms used herein are only used to describe various examples and are not intended to limit the disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "comprise", "include" and "have" indicate the presence of the described features, quantities, operations, components, elements and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements and / or combinations thereof.

[0060] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by a person of ordinary skill in the art to which the present disclosure belongs after understanding the present disclosure. Unless explicitly defined as such herein, terms (such as those defined in a general dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and should not be interpreted in an idealized or overly formal manner.

[0061] Furthermore, in the description of examples, when it is considered that a detailed description of a well-known related structure or function would cause vague interpretation of the present disclosure, such a detailed description will be omitted.

[0062] At present, the existing technical solutions do not have an effective identification and control solution for low-frequency instantaneous excitation vibration characteristics. Currently, as long as the acceleration of the unit reaches the fault threshold, the unit will immediately execute a fault shutdown. This control method has the following shortcomings: there is no real-time online automatic analysis of the vibration characteristics, and different control solutions cannot be executed according to the vibration characteristic analysis results.

[0063] The present disclosure provides a method, a control method and a device for identifying the vibration type of a wind turbine generator set, which can solve the above problems. The method, the control method and the vibration type identification method of the wind turbine generator set disclosed in the present disclosure can be applied to a server, and the server and the wind turbine generator set can be connected wirelessly or by wire, which is not limited here. The above server can be a server, or a server cluster composed of several servers, or a cloud computing platform or a virtualization center. The following is an explanation using a server as an example.

[0064] The server obtains the acceleration signal of the dominant direction of the wind turbine generator set, determines the frequency of the acceleration signal in the dominant direction, and then identifies the vibration type of the wind turbine generator set according to the frequency of the acceleration signal and the tower natural frequency of the wind turbine generator set and the rotation frequency of the wind turbine generator set. Therefore, the wind turbine generator set can be controlled accordingly according to the identified vibration type, and no longer relies solely on the acceleration amplitude to control the unit's fault shutdown. Therefore, the problem of power generation loss caused by controlling the unit's fault shutdown according to the acceleration amplitude in the prior art is effectively solved.

[0065] The present disclosure is described in detail below with reference to the accompanying drawings.

[0066] The present invention proposes a method for identifying the vibration type of a wind turbine generator set. Figure 1 FIG. 1 is a flow chart showing a method for identifying a vibration type of a wind turbine generator set according to an embodiment of the present disclosure. Figure 1 As shown, the vibration type identification method of the wind turbine generator set includes the following steps:

[0067] In step S101, an acceleration signal of a dominant direction of a wind turbine generator set is obtained.

[0068] Optionally, the acceleration signal may be detected by an acceleration sensor or other device capable of detecting an acceleration signal, which is not limited in the embodiments of the present application.

[0069] After the acceleration signal is detected by an acceleration sensor or other device, it can be transmitted to a server through the network.

[0070] The dominant direction mentioned above can be the front-to-back vibration direction of the cabin of the wind turbine generator set (subsequently replaced by the X direction) or the left-to-right vibration direction of the cabin (subsequently replaced by the Y direction). Specifically, it can be judged according to the amplitude of the X-direction acceleration signal, the amplitude of the Y-direction acceleration signal and the set dominant direction judgment threshold.

[0071] In one example, before obtaining the acceleration signal of the dominant direction of the wind turbine generator set, the acceleration signal of the cabin of the wind turbine generator set can be detected by an acceleration sensor. The acceleration signal output by the acceleration sensor is an original signal, which is divided into the X direction and the Y direction. Then, according to the amplitude of the acceleration signal in the X direction, the amplitude of the acceleration signal in the Y direction and the set dominant direction judgment threshold, it is determined that the X direction or the Y direction is the dominant direction. For example, when the amplitude of the acceleration signal in the X direction exceeds the set dominant direction judgment threshold, and the amplitude of the acceleration signal in the Y direction does not exceed the set dominant direction judgment threshold, it is determined that the dominant direction is the X direction.

[0072] In step S102 , the frequency of the acceleration signal in the dominant direction is determined.

[0073] Optionally, time domain feature marking can be used to calculate the period by counting the number of data points between two marking points, thereby calculating the frequency.

[0074] In an embodiment of the present disclosure, the step of determining the frequency of the acceleration signal in the dominant direction can be achieved by: marking the acceleration signal in the dominant direction in a predetermined marking manner; determining the frequency of the acceleration signal in the dominant direction according to the number of data between two marking points of the marked acceleration signal and the data sampling period. The predetermined marking manner includes a zero-crossing marking manner, a peak marking manner, and a trough marking manner. The zero-point marking manner is to mark each zero point of the acceleration signal curve, the peak marking manner is to mark each peak of the acceleration signal curve, and the trough marking manner is to mark each trough of the acceleration signal curve.

[0075] In the embodiment of the present application, the frequency of the acceleration signal is determined by adopting the above-mentioned marking method. Compared with the prior art, in which the frequency is obtained by fast Fourier transform, on the one hand, determining the frequency by adopting the marking method can truly reflect the vibration situation in the recent time; on the other hand, adopting the marking method can reduce the consumption of memory resources of the programmable logic controller (PLC).

[0076] For example, the frequency of the acceleration signal in the dominant direction can be determined by marking the acceleration signal in the dominant direction with a zero-crossing mark, and the sampling period of the acceleration signal in the dominant direction is 50 Hz, that is, sampling once every 0.02 s. At this time, the number of data between two marking points (that is, two zero-crossing points) is n, and the period T of the acceleration signal in the dominant direction is determined to be 0.02*n, and the frequency f of the acceleration signal in the dominant direction is further determined to be 1 / T. In this embodiment, a zero-crossing mark can be selected, because it is smoother near the zero-crossing point than at the peak and trough, and the recognition accuracy can be guaranteed without deep filtering.

[0077] The following uses the X-direction acceleration signal as an example to illustrate the frequency calculation principle. The cycle time and frequency are calculated once every half cycle, and then the cycle and frequency of the complete cycle are synthesized as needed. For example, if the zero-crossing point marking method is used, because the signal is a sine wave, the period between the two zero-crossing points is actually half a cycle, that is, there will be T1 = 0.02*n1 and T2 = 0.02*n2, then T of this complete cycle = T1+T2, and the frequency of the complete cycle f = 1 / T. It should be noted that the frequency of the last 0.25 cycle also needs to be calculated, that is, the last marking point is the moment when the XY synthesized acceleration value is greater than the set threshold. Figure 2 : is a schematic diagram showing the calculation of the acceleration period and frequency cutting in the X direction of the embodiment of the present disclosure, wherein the ordinate is the acceleration amplitude, the unit is g, the abscissa is the time axis, the time is s, 0 represents the acceleration amplitude reaching the preset value, -1 represents the acceleration amplitude reaching the preset value before 1s, -2 represents the acceleration amplitude reaching the preset value before 2s, such as Figure 2 As shown in the figure, this calculation method can completely ignore the consumption of PLC memory resources of the unit, and can accurately capture the vibration spectrum characteristics of the unit in the last three cycles or so, and is very practical for identifying the low-frequency vibration characteristics of wind turbines.

[0078] According to an embodiment of the present disclosure, before marking the acceleration signal of the dominant direction in a predetermined marking manner, the method further includes: performing low-pass filtering on the acceleration signal of the dominant direction.

[0079] By performing low-pass filtering in this embodiment, it is possible to ensure that the signal has a certain degree of smoothness when the low-frequency vibration characteristics are mainly detected and the instantaneous low-frequency vibration frequency needs to be identified later.

[0080] In step S103, the vibration type of the wind turbine generator set is identified according to the frequency of the acceleration signal, the tower natural frequency of the wind turbine generator set, and the rotation frequency of the wind turbine generator set.

[0081] After determining the frequency of the acceleration signal, the vibration type can be further identified based on the frequency of the acceleration signal, the tower natural frequency and the rotational frequency of the wind turbine. The tower natural frequency is also the natural frequency of the wind turbine tower, which can also be called the natural frequency. When an object is in free vibration, its displacement changes with time according to the sine or cosine law. The frequency of vibration has nothing to do with the initial conditions, but only with the inherent characteristics of the system (such as mass, shape, material, etc.), which is called the natural frequency.

[0082] The above-mentioned rotation frequency is the speed multiplication. For example, the speed multiplication of 1 is the speed 1p, which is calculated as n / 60, and the speed multiplication of 3 is the speed 3p, which is calculated as n / 60*3.

[0083] In one example, the vibration type of a wind turbine generator set can be identified based on the frequency of the acceleration signal, the natural frequency of the tower, and the rotational frequency of the wind turbine generator set in the following manner: first, determine whether the difference between the frequency of the acceleration signal and the natural frequency of the tower or the rotational frequency of the wind turbine generator set is within a predetermined range, and the predetermined range is determined based on actual conditions and historical experience, for example, it can be set to 10%; in response to the difference being within the predetermined range, that is, when the difference between the frequency of the acceleration signal and the natural frequency of the tower or the rotational frequency of the wind turbine generator set is within the predetermined range, determine the vibration type as the natural vibration type corresponding to the natural frequency of the tower or the rotational frequency; in response to the difference exceeding the predetermined range, that is, the difference between the frequency of the acceleration signal and the natural frequency of the tower or the rotational frequency of the wind turbine generator set is not within the predetermined range, determine the vibration type as a non-natural vibration type.

[0084] Through this embodiment, by comparing the frequency of the acceleration signal with the natural frequency of the tower or the rotational frequency of the wind turbine, the vibration type of the wind turbine is identified as an natural vibration type or a non-natural vibration type, thereby realizing the identification of the vibration type, so that the control of the wind turbine is no longer based solely on the vibration fault threshold, and adaptive control of the wind turbine can be achieved in combination with the identified vibration type.

[0085] Specifically, the frequency of the acceleration signal can be compared with the natural frequency and the rotation frequency of the tower. If the frequency of the acceleration signal is within 10% of the natural frequency and the rotation frequency, it can be determined that the frequency characteristic of the acceleration signal is the natural characteristic of the tower or the rotation frequency characteristic, and the vibration type of the wind turbine generator set is the natural vibration of the tower or the rotation frequency vibration; otherwise, it is not the natural characteristic of the tower or the rotation frequency characteristic, that is, it is not the natural vibration of the tower or the rotation frequency vibration. The above-mentioned natural vibration types may include but are not limited to: natural vibration of the tower (first-order vibration of the tower, second-order vibration of the tower, etc.), rotation frequency vibration (speed 1P vibration, speed 3P vibration, etc.), vibration during the startup process, etc.

[0086] For example, the method for identifying the rotational frequency vibration can be as follows: Figure 3 and Figure 4 As shown, Figure 3 : is a flow chart showing the X-axis instantaneous rotation frequency vibration identification method of an embodiment of the present disclosure. After determining that the dominant direction is the X-axis, when the following conditions are met, the vibration type is determined to be the X-direction rotation frequency vibration, that is, the X-axis rotation frequency vibration: the frequency of the X-direction acceleration signal in the past three complete cycles is between 0.8-1.2 times the rotation frequency & the frequency of each complete cycle is between 0.8-1.2 times the rotation frequency, or, the frequency of the X-direction acceleration signal in the past two complete cycles is between 0.8-1.2 times the rotation frequency & the frequency of each complete cycle is between 0.8-1.2 times the rotation frequency & the frequency of less than 1 / 4 cycle in the X direction at the time of the fault is between 0.65-1.55 times the rotation frequency. Figure 4 It is a flow chart showing the Y-axis instantaneous rotation frequency vibration identification method of an embodiment of the present invention. After determining that the dominant direction is the Y-axis, when the following conditions are met, the vibration type is determined to be the Y-direction rotation frequency vibration, that is, the Y-axis rotation frequency vibration: the frequency of the Y-direction acceleration signal in the past three complete cycles is between 0.8-1.2 times the rotation frequency & the frequency of each complete cycle is between 0.8-1.2 times the rotation frequency, or, the frequency of the Y-direction acceleration signal in the past two complete cycles is between 0.8-1.2 times the rotation frequency & the frequency of each complete cycle is between 0.8-1.2 times the rotation frequency & the frequency of less than 1 / 4 cycle in the Y direction at the time of the fault is between 0.65-1.55 times the rotation frequency.

[0087] The identification method of the tower natural vibration can be as follows: Figure 5 and Figure 6 As shown, Figure 5 : is a flow chart showing an X-axis instantaneous tower frequency vibration identification method of an embodiment of the present disclosure. After determining that the dominant direction is the X direction, when the following conditions are met, the vibration type is determined to be the X-direction tower natural frequency vibration, that is, the X-axis tower frequency vibration: the frequency of the X-direction acceleration signal in the past three complete cycles is between 0.8-1.2 times the rotation frequency & the frequency of each complete cycle is between 0.8-1.2 times the rotation frequency, or, the frequency of the X-direction acceleration signal in the past two complete cycles is between 0.8-1.2 times the rotation frequency & the frequency of each complete cycle is between 0.8-1.2 times the rotation frequency & the frequency of less than 1 / 4 cycle in the X direction at the time of the fault is between 0.65-1.55 times the tower frequency. Figure 6It is a flow chart showing the Y-axis instantaneous tower frequency vibration identification method of an embodiment of the present disclosure. After determining that the dominant direction is the Y direction, when the following conditions are met, the vibration type is determined to be the Y-direction tower natural frequency vibration, that is, the Y-axis tower frequency vibration: the frequency of the Y-direction acceleration signal in the past three complete cycles is between 0.8-1.2 times the rotation frequency & the frequency of each complete cycle is between 0.8-1.2 times the rotation frequency, or, the frequency of the Y-direction acceleration signal in the past two complete cycles is between 0.8-1.2 times the rotation frequency & the frequency of each complete cycle is between 0.8-1.2 times the rotation frequency & the frequency of less than 1 / 4 cycle in the Y direction at the time of the fault is between 0.65-1.55 times the tower frequency.

[0088] In addition, the above embodiment can further refine the identification of vibration types in combination with the yaw state, such as the inherent vibration type also includes but is not limited to: non-yaw state speed 3p vibration, that is, speed 3p vibration is the main vibration form of the current large impeller unit grid-connected state, and speed 3p vibration occurs in the X direction. Therefore, the judgment principle of the speed 3p vibration type is that the X-direction vibration is dominant, and the X-direction vibration frequency is the speed 3p frequency, and the unit is in a non-yaw state. Non-inherent vibration types may include but are not limited to: non-yaw state unknown type vibration, yaw state unresolved vibration type (yaw mechanical system impact vibration or other types of vibration), etc., wherein the non-yaw state unknown type vibration means that the unit is in a non-yaw state and the vibration type does not meet the speed 3p vibration characteristics; the yaw state unresolved vibration type means that the unit is in a yaw state and the vibration type does not meet the yaw state speed 3p vibration characteristics.

[0089] According to an embodiment of the present disclosure, in response to the difference being within a predetermined range, determining that the vibration type of the wind turbine generator set is the natural vibration type corresponding to the natural frequency or rotational frequency of the tower can be achieved in the following manner: when the status flag of the wind turbine generator set is greater than or equal to the first predetermined value, the current rotational speed of the wind turbine generator set is greater than or equal to the second predetermined value, the grid-connected time of the wind turbine generator set does not exceed the first predetermined time, or the wind turbine generator set is not connected to the grid, in response to the difference being within a predetermined range, that is, the difference between the frequency of the acceleration signal and the natural frequency of the tower or the rotational frequency of the wind turbine generator set is within a predetermined range, then determining that the vibration type of the wind turbine generator set is startup process vibration. The above-mentioned status flag is used to indicate the operating status of the wind turbine generator set. For example, when the wind turbine generator set is in the starting state, the status flag is 3, when the wind turbine generator set is in the accelerating state, the status flag is 4, and when the wind turbine generator set is in the grid-connected state, the status flag is 5; the above-mentioned first predetermined value, second predetermined value, and first predetermined time can all be set according to actual conditions. For example, the first predetermined value can be 4, the second predetermined value can be 0.75 times the first-order frequency of the tower, and the first predetermined time can be 15 seconds. Through this embodiment, the vibration of the startup process of the wind turbine generator set is identified.

[0090] For example, the method for identifying the vibration during the startup process can be as follows: Figure 7 As shown, when it is detected that the status flag of the wind turbine generator set is greater than or equal to 4, the current rotation speed of the wind turbine generator set is greater than or equal to 0.75 times the first-order frequency of the tower, the grid-connected time of the wind turbine generator set does not exceed 15 seconds, or the wind turbine generator set is not connected to the grid, it is determined whether the difference between the dominant direction acceleration signal frequency and the tower natural frequency or the rotation frequency is within a predetermined range, that is, whether the dominant direction vibration meets the tower frequency vibration characteristics or the rotation frequency vibration characteristics. If the judgment result is yes, it is determined that the vibration type of the wind turbine generator set is the startup process vibration.

[0091] It should be noted that the above-mentioned startup process vibration means that during the startup process, the unit speed needs to cross the resonant speed from a low speed to a grid-connected speed. In the process of crossing the resonant speed (tower frequency and rotation frequency resonance), the vibration of the severe wind conditions is excited, causing the unit to report a vibration limit failure.

[0092] According to an embodiment of the present disclosure, in response to the difference being within a predetermined range, determining that the vibration type of the wind turbine generator set is a natural vibration type corresponding to the natural frequency or rotation frequency of the tower can be achieved in the following manner: when the average speed or instantaneous speed of the wind turbine generator set is less than the minimum operating speed within the second predetermined time, the average grid-side power or instantaneous power within the second predetermined time is less than the third predetermined value, the grid-connected time of the wind turbine generator set exceeds the first predetermined time, and the wind turbine generator set is in a fully open-blade state, in response to the difference being within a predetermined range, that is, the difference between the frequency of the acceleration signal and the natural frequency of the tower or the rotation frequency of the wind turbine generator set is within a predetermined range, then determining that the vibration type of the wind turbine generator set is a low wind speed drop resonance. The above-mentioned second predetermined time and third predetermined value can be set according to actual conditions. For example, the second predetermined time can be 10, and the third predetermined value can be 0. Through this embodiment, the low wind speed drop resonance of the wind turbine generator set is identified.

[0093] Specifically, the identification method of the low wind speed drop resonance can be as follows: Figure 8 As shown, when it is detected that the average speed or instantaneous speed in the past 10 seconds is less than the minimum operating speed & the average grid-side power or instantaneous power in the past 10 seconds is less than 0 & the unit is in grid-connected state & the unit is in full propeller state & the grid-connected state has been 15 seconds, it is determined that the difference between the dominant direction acceleration signal frequency and the tower natural frequency or rotation frequency is within a predetermined range, that is, it is determined whether the dominant direction vibration meets the tower frequency vibration characteristics or the rotation frequency vibration characteristics. If the judgment result is yes, it is determined that the vibration type of the wind turbine generator set is low wind speed drop resonance.

[0094] It should be noted that the speed drops at low wind speeds, that is, the turbulence is greater at low wind speeds and the instantaneous wind direction changes greatly. Therefore, it is easy for the instantaneous wind speed to drop or the wind direction to fluctuate greatly, resulting in a decrease in the wind energy absorbed by the impeller and an inability to maintain the minimum speed of the impeller, causing the impeller speed to approach the resonance speed, thereby exciting vibration and causing the unit to exceed the vibration limit.

[0095] According to an embodiment of the present disclosure, before identifying the vibration type of the wind turbine according to the frequency of the acceleration signal, the tower natural frequency, and the rotational frequency of the wind turbine, it also includes: acquiring the tower natural frequency of the wind turbine; acquiring the rotational frequency of the wind turbine, wherein a sampling period of data used to acquire the rotational frequency is consistent with a sampling period corresponding to data used to determine the frequency of the acceleration signal.

[0096] Specifically, the process of obtaining the rotational frequency of the wind turbine generator set can be as follows: for the wind turbine generator set, it is necessary to pay attention to the rotational frequency when analyzing the vibration type, that is, it needs to be compared with the rotational frequency. The rotational frequency changes with the change of the rotational speed, generally mainly referring to the rotational speed 3p frequency and the rotational speed 1p frequency. The data duration selected when calculating the rotational frequency needs to strictly correspond to the data duration used when calculating the periodic frequency of the acceleration signal, and the arithmetic mean of the rotational speed is calculated, and then the rotational speed 1p frequency and the rotational speed 3p frequency within this time can be calculated, which is convenient for subsequent frequency comparison with the acceleration signal to clarify the vibration type.

[0097] Specifically, the process of obtaining the tower natural frequency of the wind turbine generator set can be as follows: when analyzing the low-frequency vibration type, it is necessary to compare it with the tower natural frequency, so the tower natural frequency needs to be calculated. Generally speaking, the tower natural frequency is calculated through the acceleration signal, which can be calculated using the fast Fourier transform method. The selected data is long enough to ensure accuracy. Considering that the tower natural frequency will not change for a long time, it can be selected to calculate and update once every 1 month or longer to ensure that there is no impact on the unit PLC performance.

[0098] According to the embodiments of the present disclosure, the active vibration direction determination can be as follows: Fig. 9 As shown, when the amplitude of the acceleration signal in the X direction and the amplitude of the acceleration signal in the Y direction both exceed the set dominant direction judgment threshold, the dominant direction is determined to be the X direction, the Y direction, or the XY bidirectional direction according to the amplitude of the acceleration signal in the X direction and the amplitude of the acceleration signal in the Y direction within one cycle, the absolute value of the wave peak, and the maximum amplitude.

[0099] The present disclosure also proposes a control method for a wind turbine generator set. Fig.10 FIG. 1 is a flow chart showing a control method of a wind turbine generator set according to an embodiment of the present disclosure. Fig.10 As shown, the control method of the wind turbine generator set includes the following steps:

[0100] In step S1001, the vibration type of the wind turbine generator set is identified based on the vibration type identification method of the wind turbine generator set in the above embodiment. The identification process can refer to the vibration type identification method of the wind turbine generator set in the above embodiment, which will not be discussed here.

[0101] In step S1002, a target control mode of the wind turbine generator set is determined according to the vibration type and the vibration fault threshold of the wind turbine generator set. The specific mode may be as follows:

[0102] According to an embodiment of the present disclosure, the step of determining the target control mode of the wind turbine generator set according to the vibration type and the vibration fault threshold of the wind turbine generator set can be implemented in the following manner: when the vibration type is the inherent vibration type of the wind turbine generator set, the target control mode of the wind turbine generator set is further determined according to the relationship between the amplitude of the acceleration signal and the vibration fault threshold; when the vibration type is the non-inherent vibration type of the wind turbine generator set, the target control mode of the wind turbine generator set is determined to control the wind turbine generator set to shut down. Through this embodiment, different control strategies are adopted according to different vibration types, and the wind turbine generator set is no longer controlled to shut down only by the fault threshold. For example, the vibration type that is not resolved in the non-yaw state (equivalent to the above-mentioned non-inherent vibration type) or the vibration type that is not resolved in the yaw state (most of the yaw mechanical impact vibrations, equivalent to the above-mentioned non-inherent vibration type) continues to be reported in the form of a fault to attract sufficient attention and ensure the safety of the unit.

[0103] According to an embodiment of the present disclosure, the step of determining the target control mode of the wind turbine generator set according to the relationship between the amplitude of the acceleration signal and the vibration fault threshold can be implemented in the following manner: when the number of times the amplitude of the acceleration signal reaches the vibration fault threshold within the third predetermined time does not exceed the predetermined number of times, further determining the target control mode of the wind turbine generator set according to the power of the acceleration signal; when the number of times the amplitude of the acceleration signal reaches the vibration fault threshold within the third predetermined time exceeds the predetermined number of times, determining the target control mode of the wind turbine generator set as controlling the wind turbine generator set to shut down. The above-mentioned third predetermined time is set according to actual conditions. The safety of the unit can be ensured by this embodiment.

[0104] For example, if the number of times that the amplitude of the acceleration signal reaches the vibration fault threshold within a predetermined time exceeds the preset number, it indicates that there are many severe wind conditions in the operation cycle of the unit, and it is necessary to consider re-evaluating the wind resources to ensure the safety of the unit, or the relevant vibration parameter settings are unreasonable and need to be corrected. Therefore, when the number of times that the amplitude of the acceleration signal reaches the vibration fault threshold within a predetermined time exceeds the predetermined number, the target control method of the wind turbine generator set is determined to control the wind turbine generator set to shut down, that is, at this time, it is reported to the server in the form of a fault and shut down. If it does not exceed the predetermined number within a certain time period, when the unit reaches the original design vibration fault threshold (that is, the above-mentioned vibration fault threshold), only a warning is reported and no direct shutdown is performed. At the same time as the warning is reported, a judgment is further made based on the power of the acceleration signal.

[0105] According to an embodiment of the present disclosure, the step of determining the target control mode of the wind turbine generator set according to the power of the acceleration signal can be implemented in the following manner: when the power of the acceleration signal exceeds a predetermined power value, the target control mode of the wind turbine generator set is determined to increase the minimum operating pitch angle of the wind turbine generator set and / or limit the power to reduce the load; when the power of the acceleration signal does not exceed the predetermined power value, the target control mode of the wind turbine generator set is determined to control the wind turbine generator set to shut down. The above-mentioned predetermined power is set according to actual conditions. For example, when the power is relatively low (such as less than 0.15 times the rated power), since the wind energy absorbed by the impeller is very small at this time, neither limiting the power nor increasing the minimum pitch angle will have a significant effect. At this time, the unit reports a fault and shuts down.

[0106] According to an embodiment of the present disclosure, the above-mentioned step of reducing the load by increasing the minimum operating pitch angle and / or power limit of the wind turbine generator set can be achieved in the following manner: the minimum operating pitch angle and / or power limit are increased to a preset time, and after the preset time, the original minimum operating pitch angle and power limit are restored. In the process of reducing the load by increasing the minimum operating pitch angle and / or power limit, when the amplitude of the acceleration signal reaches the stop load reduction threshold, the wind turbine generator set is controlled to shut down, wherein the stop load reduction threshold is greater than the vibration fault threshold. The above-mentioned predetermined time is set according to actual conditions. Through this embodiment, the power generation loss can be reduced, and repeated starting and stopping of the unit at high wind speeds can be avoided, thereby reducing the accumulation of fatigue loads during starting and stopping of the unit.

[0107] For example, when the power is relatively high (such as more than 0.15 times the rated power), the unit can be instantly unloaded by briefly increasing the minimum operating pitch angle and power limit of the unit, while attenuating vibration (for example, increasing the minimum operating pitch angle for 1 minute and limiting power output for 5 minutes), and the limit is released after the set limit time is reached. During the load reduction control process, if the effective value of the acceleration signal exceeds the preset threshold for stopping the load reduction control (that is, the above-mentioned stop load reduction threshold), a fault shutdown can be performed immediately (the threshold for stopping the load reduction control is greater than the original design vibration fault threshold). The main consideration for increasing the minimum operating pitch angle is that the wind conditions are relatively bad when vibration occurs. Increasing the minimum operating pitch angle can reduce the load and avoid the risk of tower sweeping. When the vibration exceeds the limit, the wind conditions are relatively bad. Vibration transient load reduction control can be used to reduce the grid-connected state load of the unit, thereby reducing the power generation loss, avoiding repeated start and shutdown of the unit at high wind speeds, and reducing the accumulation of fatigue loads of the unit start and shutdown.

[0108] According to an embodiment of the present disclosure, the step of determining the target control mode of the wind turbine generator set according to the vibration type and the vibration fault threshold of the wind turbine generator set can be implemented in the following manner: when the vibration type is the inherent vibration type of the wind turbine generator set and the number of times the vibration amplitude of the acceleration exceeds the predetermined number within the fourth predetermined time, the target control mode is determined to be to reduce the amplitude of the acceleration signal by limiting power, wherein the first preset threshold is less than the vibration fault threshold. The fourth predetermined time, the first preset threshold, and the predetermined number of times are set according to actual conditions. For example, for frequent high-amplitude low-frequency vibrations caused by severe wind conditions, although the unit has not reached the vibration fault threshold and has not reported a fault, it will affect the fatigue load safety of the unit. Closed-loop control can be implemented based on the amplitude of the vibration acceleration signal, thereby reducing fatigue damage to the unit.

[0109] According to an embodiment of the present disclosure, the step of reducing the amplitude of the acceleration signal by limiting power can be implemented in the following manner: cyclically adjusting the power limit to reduce the amplitude of the acceleration signal until the amplitude of the acceleration signal reaches a second preset threshold, wherein the second preset threshold is less than the first preset threshold. The second preset threshold is set according to actual conditions. For example, a specific control scheme may be to reduce the acceleration amplitude of the unit under severe wind conditions by limiting power, and further adjust the power limit value according to the acceleration amplitude feedback during the previous power limit window period until the acceleration amplitude control requirement is met.

[0110] The following is an example of the X-direction speed 3p vibration closed-loop control scheme. The identification control process is as follows Fig.11 As shown, step 1, determine the dominant direction of vibration: when the peak value of the acceleration signal synthesis value is greater than 0.06g within 5 minutes, the proportion z1 of the X direction as the dominant direction exceeds 0.7 (the determination method of the X direction as the dominant direction refers to the above Fig. 9As mentioned above, which will not be discussed here), the X direction is judged to be the dominant direction. It should be noted that g is the acceleration due to gravity, g = 9.8 m / s.

[0111] Step 2, determine whether the vibration frequency in the dominant vibration direction meets the frequency required by the closed-loop control scheme (for example, the rotation speed 3p frequency). The determination process can be carried out in the following two ways:

[0112] Method 1: If the PLC can support the fast Fourier transform algorithm, the fast Fourier method can be used. The specific process can be: according to the X-direction acceleration signal within the 20s window period within 5 minutes, the fast Fourier algorithm is used to calculate the speed 3p frequency amplitude. When the calculated frequency amplitude is greater than 0.02 and the proportion z3 is greater than 0.5, it is determined that the vibration frequency meets the control requirements;

[0113] Method 2: Obtain the frequency at which the acceleration signal amplitude in the X direction exceeds 0.05g within 5 minutes. When the proportion z2 of the frequency type of speed 3p in the obtained frequency exceeds 0.5, it is determined that the vibration frequency meets the control requirements.

[0114] If the result is yes, go to step 3, if the result is no, go to step 5;

[0115] Step 3, determine whether the vibration level in the dominant vibration direction meets the control requirements: when the proportion k of the peak value of the acceleration signal in the X direction exceeding 0.06g for 5 minutes exceeds 0.2, it is determined that the vibration level in the dominant vibration direction meets the control requirements; when the judgment result is yes, go to step 4, when the judgment result is no, go to step 5;

[0116] Step 4, determine whether the power limit value for more than 5 minutes is greater than 1.2 times the minimum power limit value allowed by the unit. When the judgment result is yes, perform the shutdown operation. When the judgment result is no, lower the power limit value output by the unit;

[0117] Step 5, enter the closed-loop vibration control mode. When the adjusted acceleration amplitude meets the control requirement, further determine whether the proportion k exceeds 0.2; if it exceeds 0.2, adjust the power limit of the unit output. If it does not exceed 0.2, go to step 6;

[0118] Step 6: Enter the closed-loop vibration control mode.

[0119] In step S1003, the target control method is applied to control the wind turbine generator set.

[0120] The above-mentioned target control method includes but is not limited to: 1) controlling the wind turbine generator set to shut down; 2) increasing the minimum operating pitch angle of the wind turbine generator set and / or limiting power to reduce load; 3) reducing the amplitude of the acceleration signal by limiting power.

[0121] For example, when the target control mode is to control the wind turbine to shut down, the wind turbine is controlled to shut down; when the target control mode is to increase the minimum operating pitch angle of the wind turbine and / or limit the power to reduce the load, the target control mode is applied to control the wind turbine to increase the minimum operating pitch angle and / or limit the power to reduce the load; when the target control mode is to reduce the amplitude of the acceleration signal by limiting the power, the target control mode is applied to control the wind turbine to reduce the amplitude of the acceleration signal.

[0122] The above-mentioned embodiments of the present disclosure provide a method for identifying the vibration type of a wind turbine generator set, namely, processing the acceleration signal of the wind turbine generator set and making a comprehensive judgment with the tower natural frequency, rotation speed, and operating status of the unit to analyze the vibration type of the unit, and then adopting different control schemes according to the different vibration types identified, such as combining the design characteristics of the unit, suppressing the vibration of instantaneous excitation that does not affect the safety of the unit through instantaneous pitch control and power control, and the unit resumes normal operation after the vibration is suppressed, avoiding repeated failures and starting and stopping of the unit, and reducing power generation losses; and for vibration types with high acceleration amplitudes at high frequencies but not reaching the fault threshold, vibration closed-loop control is performed to reduce fatigue damage of the unit. The above embodiments can improve the level of intelligent operation and maintenance of the unit and reduce maintenance costs.

[0123] The above embodiments are described systematically below. Fig.12 is a flow chart showing the overall control flow of an embodiment of the present disclosure, such as Fig.12 As shown in the figure, the process requires the following modules: acceleration signal detection module, original acceleration signal low-pass filter processing module, dominant direction vibration signal spectrum feature calculation module, vibration dominant direction judgment module, frequency conversion calculation module, tower natural modal frequency calculation module, vibration feature analysis module and transient control scheme matching module based on vibration feature analysis results. The functions of each module are as follows:

[0124] Acceleration signal detection module: used to detect the acceleration signal of the cabin. The output acceleration signal is the original signal, which is divided into the front and rear direction (subsequently replaced by the X direction) and the left and right direction (subsequently replaced by the Y direction).

[0125] The low-pass filter processing module of the original acceleration signal focuses on detecting the low-frequency vibration characteristics, and the subsequent need to identify the instantaneous low-frequency vibration frequency requires ensuring that the signal has a certain degree of smoothness. Therefore, low-pass filtering is required here.

[0126] Vibration dominant direction judgment module: mainly used to judge the dominant direction of instantaneous low-frequency vibration.

[0127] Dominant direction vibration signal spectrum feature calculation module: Use time domain feature marking to calculate the period and frequency by calculating the number of data points between two marking points. For example, the data sampling period is 50Hz, that is, sampling once every 0.02s, and the number of data between two marking points is n, then the period T = 0.02*n; then the frequency f = 1 / T.

[0128] Frequency calculation module: calculates the 1p frequency and 3p frequency of the rotation speed, so as to facilitate the subsequent frequency comparison with the acceleration signal and clarify the vibration characteristics.

[0129] Tower natural modal frequency calculation module: The tower natural modal frequency can be calculated through acceleration signal or by fast Fourier transform.

[0130] Vibration feature analysis module: compare the frequency characteristics of the acceleration signal with the natural modal frequency and rotation frequency of the unit tower, and clarify the vibration type in combination with the yaw state, but not limited to this. For example, the identification of the unit startup process and the identification of the speed jump process can be added to further refine the vibration type. For the low-frequency vibration identification of wind turbines, the main vibration types that need to be analyzed can be but are not limited to: first-order vibration of the tower, rotation frequency vibration, vibration during the startup process, yaw vibration, unknown type vibration, etc. Specifically, the frequency characteristics of the acceleration signal are compared with the first-order and rotation frequency of the tower, that is, the size is compared. For example, if the two are close to 10%, it can be judged that the frequency characteristics of the acceleration signal are the first-order or rotation frequency characteristics of the tower, otherwise it is not the first-order vibration or rotation frequency vibration of the tower; the yaw state is whether the unit is yawing. If the unit is yawing but the acceleration characteristics meet the first-order of the tower or the speed 3p, then the vibration is not caused by the yaw action.

[0131] Transient control scheme matching module based on vibration feature analysis results: By identifying the vibration type and matching the corresponding control scheme, the significance of this module is to make the unit's monitoring of vibration exceeding the limit more intelligent, while ensuring the safety of the unit, reducing power generation losses, or reducing the overall load of the unit, and also reducing the maintenance efficiency of operation and maintenance personnel and reducing the intervention of R&D personnel.

[0132] The method proposed in the present disclosure processes the vibration detection signal and uses characteristic marking to calculate the dominant frequency of the instantaneous low-frequency vibration of the computer group (the dominant frequency can be calculated for half a cycle continuously, and the instantaneous vibration identification is accurate and timely), which is more accurate than the fast Fourier solution and does not consume PLC memory resources, so it is more suitable for low-frequency vibration identification in the field of wind turbines. In addition, combined with the design characteristics of the unit, the instantaneous excitation vibration that does not affect the safety of the unit is suppressed by instantaneous pitch control and power control. After the vibration is suppressed, the unit resumes normal operation, avoiding repeated failures and starting and stopping of the unit, and reducing power generation losses; vibration closed-loop control is performed for vibration types with high acceleration amplitudes at a high level but not reaching the fault threshold and vibration characteristics belonging to the recognized safety category, so as to reduce long-term fatigue damage of the unit; the above improves the level of intelligent operation and maintenance of the unit and reduces maintenance costs.

[0133] Fig.13 is a block diagram showing a vibration type identification device for a wind turbine generator set disclosed in the present invention, such as Fig.13 As shown, the device comprises:

[0134] A first acquisition module 130 is used to acquire an acceleration signal of a dominant direction of a wind turbine generator set;

[0135] A first determination module 132, configured to determine the frequency of the acceleration signal in the dominant direction;

[0136] The first identification module 134 is used to identify the vibration type of the wind turbine generator set according to the frequency of the acceleration signal, the natural frequency of the tower, and the rotation frequency of the wind turbine generator set.

[0137] According to an embodiment of the present disclosure, the first identification module 134 is also used to determine whether the difference between the frequency of the acceleration signal and the natural frequency of the tower or the rotational frequency of the wind turbine is within a predetermined range; in response to the difference being within the predetermined range, determining the vibration type as the natural vibration type corresponding to the natural frequency of the tower or the rotational frequency; in response to the difference exceeding the predetermined range, determining the vibration type as a non-natural vibration type.

[0138] According to an embodiment of the present disclosure, the first identification module 134 is also used to determine that the vibration type of the wind turbine is startup process vibration in response to a difference being within a predetermined range when the status flag of the wind turbine is greater than or equal to a first predetermined value, the current speed of the wind turbine is greater than or equal to a second predetermined value, the grid-connected time of the wind turbine does not exceed the first predetermined time, or the wind turbine is not connected to the grid.

[0139] According to an embodiment of the present disclosure, the first identification module 134 is also used to determine that the vibration type of the wind turbine is a low wind speed drop resonance in response to a difference being within a predetermined range when the average speed or instantaneous speed of the wind turbine is less than the minimum operating speed within a second predetermined time, the average grid-side power or instantaneous power within the second predetermined time is less than a third predetermined value, the grid-connected time of the wind turbine exceeds the first predetermined time, and the wind turbine is in a fully propeller-opening state.

[0140] According to an embodiment of the present disclosure, the first determination module 132 is further used to mark the acceleration signal of the dominant direction in a predetermined marking manner; and determine the frequency of the acceleration signal of the dominant direction according to the number of data between two marking points of the marked acceleration signal and the data sampling period.

[0141] According to an embodiment of the present disclosure, the above-mentioned predetermined marking method includes a zero-crossing marking method, a peak marking method, and a trough marking method.

[0142] According to an embodiment of the present disclosure, the first determination module 132 is further configured to perform low-pass filtering on the acceleration signal in the dominant direction before marking the acceleration signal in the dominant direction in a predetermined marking manner.

[0143] Fig.14 is a block diagram showing a control device of a wind turbine generator set of the present disclosure, such as Fig.14 As shown, the device comprises:

[0144] A second identification module 140, used for the vibration type identification device of the wind turbine generator set to identify the vibration type of the wind turbine generator set;

[0145] A second determination module 142 is used to determine a target control mode of the wind turbine generator set according to the vibration type and the vibration fault threshold of the wind turbine generator set;

[0146] The control module 144 is used to control the wind turbine generator set by applying a target control method.

[0147] According to an embodiment of the present disclosure, the second determination module 142 is also used to determine the target control mode of the wind turbine generator set according to the relationship between the amplitude of the acceleration signal and the vibration fault threshold when the vibration type is the inherent vibration type of the wind turbine generator set; when the vibration type is the non-inherent vibration type of the wind turbine generator set, the target control mode of the wind turbine generator set is determined to be controlling the wind turbine generator set to shut down.

[0148] According to an embodiment of the present disclosure, the second determination module 142 is also used to determine the target control mode of the wind turbine generator set according to the power of the acceleration signal when the number of times the amplitude of the acceleration signal reaches the vibration fault threshold within a third predetermined time does not exceed a predetermined number of times; and to determine the target control mode of the wind turbine generator set to control the wind turbine generator set to shut down when the number of times the amplitude of the acceleration signal reaches the vibration fault threshold within the third predetermined time exceeds a predetermined number of times.

[0149] According to an embodiment of the present disclosure, the second determination module 142 is also used to determine the target control mode of the wind turbine generator set to increase the minimum operating pitch angle of the wind turbine generator set and / or limit the power to reduce the load when the power of the acceleration signal exceeds a predetermined power value; when the power of the acceleration signal does not exceed the predetermined power value, determine the target control mode of the wind turbine generator set to control the wind turbine generator set to shut down.

[0150] According to an embodiment of the present disclosure, the second determining module 142 is further configured to increase the minimum operating pitch angle and / or the power limit to a preset time, and restore the original minimum operating pitch angle and power limit after the preset time.

[0151] According to an embodiment of the present disclosure, the second determination module 142 is also used to control the wind turbine generator set to shut down when the amplitude of the acceleration signal reaches a stop load reduction threshold during the process of increasing the minimum operating pitch angle and / or limiting the power to reduce the load, wherein the stop load reduction threshold is greater than the vibration fault threshold.

[0152] According to an embodiment of the present disclosure, the second determination module 142 is also used to determine that the target control method is to reduce the amplitude of the acceleration signal by limiting power when the vibration type is the inherent vibration type of the wind turbine generator set and the vibration amplitude of the acceleration within the fourth predetermined time exceeds the first preset threshold for a predetermined number of times, wherein the first preset threshold is less than the vibration fault threshold.

[0153] According to an embodiment of the present disclosure, the second determination module 142 is further configured to cyclically adjust the power limit to reduce the amplitude of the acceleration signal until the amplitude of the acceleration signal reaches a second preset threshold, wherein the second preset threshold is smaller than the first preset threshold.

[0154] According to an embodiment of the present disclosure, a computer-readable storage medium storing instructions is provided, wherein, when the instructions are executed by at least one computing device, the at least one computing device is prompted to execute a vibration type identification method for a wind turbine generator set or a control method for a wind turbine generator set as described in any of the above embodiments.

[0155] According to an embodiment of the present disclosure, a system is provided, comprising at least one computing device and at least one storage device storing instructions, wherein the instructions, when executed by the at least one computing device, prompt the at least one computing device to execute a vibration type identification method for a wind turbine generator set or a control method for a wind turbine generator set as in any of the above-mentioned embodiments.

[0156] Although some embodiments of the present disclosure have been shown and described, it will be appreciated by those skilled in the art that modifications may be made to the embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for identifying vibration types of wind turbine generator sets. It is characterized in that include: Acquiring an acceleration signal of a dominant direction of the wind turbine generator set; determining the frequency of the acceleration signal in the dominant direction; Identify the vibration type of the wind turbine generator set according to the frequency of the acceleration signal, the tower natural frequency of the wind turbine generator set, and the rotation frequency of the wind turbine generator set; Wherein, identifying the vibration type of the wind turbine generator set according to the frequency of the acceleration signal, the tower natural frequency of the wind turbine generator set, and the rotation frequency of the wind turbine generator set includes: Determining whether a difference between the frequency of the acceleration signal and the natural frequency of the tower or the rotation frequency is within a predetermined range; In response to the difference being within a predetermined range, determining the vibration type to be a natural vibration type corresponding to the natural frequency of the tower or the rotation frequency; In response to the difference exceeding a predetermined range, the vibration type is determined to be an extrinsic vibration type.

2. The vibration type identification method according to claim 1, It is characterized in that In response to the difference being within a predetermined range, determining that the vibration type of the wind turbine generator set is a natural vibration type corresponding to the natural frequency of the tower or the rotation frequency comprises: When the status flag of the wind turbine generator set is greater than or equal to a first predetermined value, the current rotation speed of the wind turbine generator set is greater than or equal to a second predetermined value, the grid-connected time of the wind turbine generator set does not exceed the first predetermined time, or the wind turbine generator set is not connected to the grid, in response to the difference being within a predetermined range, it is determined that the vibration type of the wind turbine generator set is startup process vibration.

3. The vibration type identification method according to claim 1, It is characterized in that In response to the difference being within a predetermined range, determining that the vibration type of the wind turbine generator set is a natural vibration type corresponding to the natural frequency of the tower or the rotation frequency comprises: When the average speed or the instantaneous speed of the wind turbine generator set within the second predetermined time is less than the minimum operating speed, the average grid-side power or the instantaneous power within the second predetermined time is less than the third predetermined value, the grid-connected time of the wind turbine generator set exceeds the first predetermined time and the wind turbine generator set is in a fully-opened state, in response to the difference being within a predetermined range, the vibration type of the wind turbine generator set is determined to be low wind speed drop resonance.

4. The vibration type identification method according to claim 1, It is characterized in that The step of determining the frequency of the acceleration signal in the dominant direction comprises: marking the acceleration signal of the dominant direction in a predetermined marking manner; The frequency of the acceleration signal in the dominant direction is determined according to the number of data between two marking points of the marked acceleration signal and the data sampling period.

5. The vibration type identification method as claimed in claim 4, It is characterized in that The predetermined marking method includes a zero-crossing marking method, a peak marking method, and a trough marking method.

6. The vibration type identification method as claimed in claim 4, It is characterized in that Before marking the acceleration signal of the dominant direction in a predetermined marking manner, the method further includes: The acceleration signal in the dominant direction is subjected to low-pass filtering.

7. A control method for a wind turbine generator set, It is characterized in that include: Identify the vibration type of the wind turbine generator set based on the vibration type identification method of the wind turbine generator set according to any one of claims 1 to 6; Determining a target control mode of the wind turbine generator set according to the vibration type and the vibration fault threshold of the wind turbine generator set; The target control method is applied to control the wind turbine generator set.

8. The control method according to claim 7, It is characterized in that Determining a target control method of the wind turbine generator set according to the vibration type and the vibration fault threshold of the wind turbine generator set includes: When the vibration type is the natural vibration type of the wind turbine generator set, determining a target control mode of the wind turbine generator set according to a relationship between the amplitude of the acceleration signal and the vibration fault threshold; When the vibration type is a non-natural vibration type of the wind turbine generator set, the target control mode of the wind turbine generator set is determined to be controlling the wind turbine generator set to shut down.

9. The control method according to claim 8, It is characterized in that Determining the target control mode of the wind turbine generator set according to the relationship between the amplitude of the acceleration signal and the vibration fault threshold includes: When the number of times that the amplitude of the acceleration signal reaches the vibration fault threshold value within a third predetermined time does not exceed a predetermined number, determining a target control mode of the wind turbine generator set according to the power of the acceleration signal; When the number of times that the amplitude of the acceleration signal reaches the vibration fault threshold within the third predetermined time exceeds the predetermined number, the target control mode of the wind turbine generator set is determined to be controlling the wind turbine generator set to shut down.

10. The control method according to claim 9, It is characterized in that Determining the target control mode of the wind turbine generator set according to the power of the acceleration signal includes: When the power of the acceleration signal exceeds a predetermined power value, determining the target control mode of the wind turbine generator set to increase the minimum operating pitch angle of the wind turbine generator set and / or limit the power to reduce the load; When the power of the acceleration signal does not exceed the predetermined power value, the target control mode of the wind turbine generator set is determined to be controlling the wind turbine generator set to shut down.

11. The control method according to claim 10, It is characterized in that Increasing the minimum operating pitch angle and / or limiting the power of the wind turbine to reduce the load includes: The minimum operating pitch angle and / or the power limit are increased for a preset time, and after the preset time, the original minimum operating pitch angle and power limit are restored.

12. The control method according to claim 10, It is characterized in that Also includes: In the process of increasing the minimum operating pitch angle and / or the limited power to reduce load, when the amplitude of the acceleration signal reaches a stop load reduction threshold, the wind turbine generator set is controlled to shut down, wherein the stop load reduction threshold is greater than the vibration fault threshold.

13. The control method according to claim 7, It is characterized in that Determining a target control method of the wind turbine generator set according to the vibration type and the vibration fault threshold of the wind turbine generator set includes: When the vibration type is the inherent vibration type of the wind turbine generator set and the vibration amplitude of the acceleration exceeds the first preset threshold for a predetermined number of times within a fourth predetermined time, it is determined that the target control method is to reduce the amplitude of the acceleration signal by limiting power, wherein the first preset threshold is less than the vibration fault threshold.

14. The control method according to claim 13, It is characterized in that Reducing the amplitude of the acceleration signal by limiting power includes: The power limit is cyclically adjusted to reduce the amplitude of the acceleration signal until the amplitude of the acceleration signal reaches a second preset threshold, wherein the second preset threshold is less than the first preset threshold.

15. A vibration type identification device for a wind turbine generator set, It is characterized in that include: A first acquisition module, used to acquire an acceleration signal of a dominant direction of the wind turbine generator set; A first determination module, configured to determine the frequency of the acceleration signal in the dominant direction; A first identification module, configured to identify the vibration type of the wind turbine generator set according to the frequency of the acceleration signal, the natural frequency of the tower, and the rotation frequency of the wind turbine generator set; Among them, the first identification module is also used to determine whether the difference between the frequency of the acceleration signal and the tower natural frequency or the rotation frequency is within a predetermined range; in response to the difference being within the predetermined range, determining that the vibration type is an inherent vibration type corresponding to the tower natural frequency or the rotation frequency; in response to the difference exceeding the predetermined range, determining that the vibration type is a non-inherent vibration type.

16. A control device for a wind turbine generator set, It is characterized in that include: A second identification module, configured to identify the vibration type of the wind turbine generator set based on the vibration type identification device of the wind turbine generator set according to claim 15; A second determination module is used to determine a target control mode of the wind turbine generator set according to the vibration type and the vibration fault threshold of the wind turbine generator set; A control module is used to control the wind turbine generator set by applying the target control method.

17. A computer-readable storage medium storing instructions, in, When the instructions are executed by at least one computing device, the at least one computing device is prompted to execute the vibration type identification method of a wind turbine generator set as claimed in any one of claims 1 to 6 or the control method of a wind turbine generator set as claimed in any one of claims 7 to 14.

18. A system comprising at least one computing device and at least one storage device storing instructions, in, When the instructions are executed by the at least one computing device, the at least one computing device is prompted to execute the vibration type identification method of the wind turbine generator set according to any one of claims 1 to 6 or the control method of the wind turbine generator set according to any one of claims 7 to 14.

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