CN108879786B - Method and device for identifying frequency and damping ratio of main components of wind generating set - Google Patents
Method and device for identifying frequency and damping ratio of main components of wind generating set Download PDFInfo
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Abstract
The invention discloses a method for identifying the frequency and the damping ratio of main components of a wind generating set, which comprises the following steps: acquiring input data and output data of main components of a wind generating set system, and respectively taking the input data and the output data as input quantity and output quantity of a fan model established through nonlinear system identification; calculating model parameters of the fan model and a transfer function of a main component; calculating a pole of a transfer function to obtain a first frequency range, performing power spectrum analysis on output data of the main component to obtain a second frequency range, and reducing the range of the first frequency range by using the second frequency range to obtain a frequency iteration range; calculating the amplitude corresponding to each frequency in the frequency iteration range, obtaining the maximum amplitude, the target frequency corresponding to the maximum amplitude and the target pole p, and obtaining the maximum amplitude, the target frequency corresponding to the maximum amplitude and the target pole p by
The damping ratio of the main component is calculated. According to the technical scheme disclosed by the application, the accuracy of identifying the frequency and the damping ratio of the main part can be improved, and the identification method is simple and easy to operate.
Description
Technical Field
The invention relates to the technical field of wind power generation, in particular to a method, a device and equipment for identifying the frequency and the damping ratio of main components of a wind generating set and a computer readable storage medium.
Background
The wind power generation set system is composed of a plurality of components, and the main components comprise a blade, a tower, a transmission chain, a gear box, a variable pitch system and the like. When a wind generating set simulation model is built, the accurate setting of main component parameters is of great importance for model simulation. In addition, before the wind generating set has larger faults, the frequency and the damping ratio of the main components can be changed, the frequency and the damping ratio of the main components of the wind generating set can be accurately monitored and identified, and the faults can be predicted in advance, so that the wind generating set can be conveniently checked in advance, and the fault occurrence rate of the wind generating set is reduced.
At present, the frequency and the damping ratio of main components are usually obtained through a mechanism modeling method, which describes each subsystem of a wind turbine generator system by using various data equations, specifically, under the condition of known intrinsic parameters (such as lift coefficient, drag coefficient, blade chord length, installation angle and the like) of the wind turbine generator system, relevant parameters (such as wind angular velocity, wind speed, adjustable pitch angle and the like) are input, and then a series of formula derivation and condition simplification are performed according to complex energy conversion and aerodynamic principles to obtain a transfer function, so that the frequency and the damping ratio of the main components are obtained. Because the data model obtained by the method is subjected to condition simplification, the difference between the data model and the model in the actual situation is large, so that the identification accuracy is reduced, and the method is complex in operation and large in calculation amount.
In summary, how to improve the accuracy of identifying the frequency and the damping ratio of the main components of the wind turbine generator system, reduce the complexity of the operation, and reduce the calculation amount is a technical problem to be solved by those skilled in the art.
Disclosure of Invention
In view of the above, the present invention provides a method, an apparatus, a device and a computer readable storage medium for identifying a frequency and a damping ratio of a main component of a wind turbine generator system, so as to improve the accuracy of identifying the frequency and the damping ratio of the main component of the wind turbine generator system, reduce the complexity of operation and reduce the amount of calculation.
In order to achieve the above purpose, the invention provides the following technical scheme:
a method for identifying the frequency and the damping ratio of main components of a wind generating set comprises the following steps:
acquiring input data and output data of main components of a wind generating set system, and respectively using the input data and the output data as input quantity and output quantity of a fan model established in advance through nonlinear system identification;
calculating model parameters of the fan model, and calculating a transfer function of the main component according to the fan model;
calculating a pole of the transfer function to obtain a first frequency range of the main component corresponding to the pole, performing power spectrum analysis on output data of the main component to obtain a second frequency range corresponding to the main component, and reducing the frequency range of the first frequency range by using the second frequency range to obtain a frequency iteration range;
calculating the amplitude corresponding to each frequency in the frequency iteration range, obtaining the maximum amplitude, and the target frequency and the target pole p corresponding to the maximum amplitude, and processing the frequency iteration range by the steps of
Calculating the damping ratio of the main part, wherein ξ is the damping ratio, real (p) is the real part of the target pole p, and imag (p) is the imaginary part of the target pole p.
Preferably, the main component is a transmission chain or a tower;
the input data of the transmission chain is the torque of the generator, and the output data is the rotating speed of the generator;
the input data of the tower is a blade pitch angle, and the output data is a tower speed.
Preferably, the fan model is specifically an extended autoregressive moving average model: a (q)-1)y(k)＝B(q-1)u(k)+C(q-1)e(k)；
Wherein the content of the first and second substances,
q-1for the backward shift operator, k is the input number, anIs a polynomial A (q)-1) Parameter value of (a), bnIs a polynomial B (q)-1) Parameter value of cnIs a polynomial C (q)-1) N is the model order, y (k) is the k-th output quantity, u (k) is the k-th input quantity, and e (k) is the k-th noise signal.
Preferably, calculating model parameters of the wind turbine model, and calculating a transfer function of the main component according to the wind turbine model includes:
deforming the extended autoregressive moving average model to obtain a deformation formula y (k) ═ a1y(k-1)-...-any(k-n)+b1u(k-1)+...+bnu(k-1)+c1e(k-1)+...+cne(k-n)；
Introducing vectors
According to the vector, a recursive formula of theta is obtained by utilizing a recursive least square method:
calculating a model parameter a in the deformation formula through the recursion formula and theta (0) and P (0)i、bi、ci，i＝1,2...n；
Performing a Laplace transform on y (k) in the warping formula: y(s) ═ L [ y (k)]And performing a Laplace transform on u (k): u(s) ═ L [ u (k)]Calculating the transfer function of the main part through Y(s) and U(s)
Preferably, the power spectrum analysis of the output data of the main component includes:
and carrying out power spectrum analysis on the output data of the main component by using an average periodogram method.
An identification device for the frequency and the damping ratio of main components of a wind generating set comprises:
an acquisition module to: acquiring input data and output data of main components of a wind generating set system, and respectively using the input data and the output data as input quantity and output quantity of a fan model established in advance through nonlinear system identification;
a first computing module to: calculating model parameters of the fan model, and calculating a transfer function of the main component according to the fan model;
a second calculation module to: calculating a pole of the transfer function to obtain a first frequency range of the main component corresponding to the pole, performing power spectrum analysis on output data of the main component to obtain a second frequency range corresponding to the main component, and reducing the frequency range of the first frequency range by using the second frequency range to obtain a frequency iteration range;
a third calculation module to: calculating the amplitude corresponding to each frequency in the frequency iteration range, obtaining the maximum amplitude, and the target frequency and the target pole p corresponding to the maximum amplitude, and processing the frequency iteration range by the steps of
Calculating the damping ratio of the main part, wherein ξ is the damping ratio, real (p) is the real part of the target pole p, and imag (p) is the imaginary part of the target pole p.
An identification device for the frequency and damping ratio of main components of a wind generating set comprises:
a memory for storing a computer program;
a processor for implementing the steps of the method for identifying the frequency and damping ratio of the wind turbine generator system main component as described in any one of the above when the computer program is executed.
A computer-readable storage medium having stored thereon a computer program which, when being executed by a processor, carries out the steps of the method for identifying a wind park main component frequency and damping ratio according to any of the preceding claims.
The invention provides a method, a device, equipment and a computer readable storage medium for identifying the frequency and the damping ratio of main components of a wind generating set, wherein the method comprises the following steps: acquiring input data and output data of main components of a wind generating set system, and respectively using the input data and the output data as input quantity and output quantity of a fan model established by nonlinear system identification in advance; calculating model parameters of the fan model, and calculating a transfer function of a main component according to the fan model; calculating a pole of the transfer function to obtain a first frequency range of the main component corresponding to the pole, performing power spectrum analysis on output data of the main component to obtain a second frequency range corresponding to the main component, and reducing the frequency range of the first frequency range by using the second frequency range to obtain a frequency iteration range; calculating the amplitude corresponding to each frequency in the frequency iteration range, obtaining the maximum amplitude, the target frequency corresponding to the maximum amplitude and the target pole p, and obtaining the maximum amplitude and the target pole p by
And calculating the damping ratio of the main part, wherein xi is the damping ratio, real (p) is the real part of the target pole p, and imag (p) is the imaginary part of the target pole p.
According to the technical scheme, the nonlinear fan model is established in advance through nonlinear system identification, so that the established fan model is closer to the characteristic of the wind power generation unit system. The acquired input data and output data of the main components of the wind turbine generator system are respectively used as the input quantity and the output quantity of the wind turbine model, and the transfer function of the main components is calculated after the model parameters of the wind turbine model are calculated, so that the condition simplification and the idealization do not exist in the process of calculating the transfer function. Then, a first frequency range corresponding to the pole is obtained by calculating the pole of the transfer function, and the first frequency range is narrowed by using a second frequency range obtained when the output data of the main component is subjected to power spectrum analysis, so that a frequency iteration range is obtained. After the frequency iteration range is obtained, the amplitude corresponding to each frequency in the frequency iteration range is calculated, the maximum amplitude, the target frequency corresponding to the maximum amplitude and the target pole are obtained, the damping ratio of the main component is calculated through the real part and the imaginary part of the target pole, the accuracy of identifying the frequency and the damping ratio of the main component can be improved through the identification method, and the identification method is simple and easy to operate and has low calculated amount.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a flowchart of a method for identifying a frequency and a damping ratio of main components of a wind turbine generator system according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a variable speed variable pitch wind turbine generator system according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram illustrating an embodiment of the present invention for identifying the frequency and damping ratio of a transmission chain or a tower;
FIG. 4 is a schematic structural diagram illustrating an RLS-based identification of the frequency and damping ratio of a wind turbine generator set drive chain or tower;
fig. 5 is a schematic structural diagram of an identification device for frequency and damping ratio of main components of a wind turbine generator system according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of an apparatus for identifying a frequency and a damping ratio of main components of a wind turbine generator system according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, a flowchart of a method for identifying a frequency and a damping ratio of a main component of a wind turbine generator system according to an embodiment of the present invention is shown, where the method includes:
s11: the method comprises the steps of obtaining input data and output data of main components of a wind generating set system, and taking the input data and the output data as input quantity and output quantity of a fan model established through nonlinear system identification in advance.
The method comprises the steps of analyzing the process of capturing wind energy of a wind generating set system from a transmission system to the rotating speed of a generator in advance, analyzing various model structures according to the motion rule of the wind generating set system, and establishing a fan model similar to the characteristics of the wind generating set system through nonlinear system identification.
According to the characteristics of the wind generating set system, input data and output data of main components required for identification are obtained, wherein the time for collecting the input data and the output data can be selected from sampling time inside the wind generating set system, so that automatic collection of the input data and the output data is facilitated. After the input data and the output data of the main component are acquired, the input data of the main component can be used as the input quantity of the fan model, and the output data of the main component can be used as the output quantity of the fan model.
S12: and calculating model parameters of the fan model, and calculating a transfer function of the main part according to the fan model.
After the acquired input data and output data of the main components are respectively used as the input quantity and the output quantity of the fan model, model parameters of the fan model can be calculated.
After the model parameters of the fan model are determined, the transfer function of the main component can be calculated according to the established fan model, so that the frequency and the damping ratio of the main component can be identified according to the transfer function.
S13: calculating a pole of the transfer function to obtain a first frequency range of the main component corresponding to the pole, performing power spectrum analysis on output data of the main component to obtain a second frequency range corresponding to the main component, and reducing the frequency range of the first frequency range by using the second frequency range to obtain a frequency iteration range.
After the transfer function of the main component is calculated according to the fan model, the transfer function is subjected to Berde plot analysis, and the zero point and the pole point of the transfer function are calculated, wherein each zero point and each pole point respectively correspond to one frequency, one amplitude and one damping ratio. Therefore, after calculating the zero and the pole of the transfer function, the frequency range corresponding to the zero and the pole can be obtained. Since the frequency and the damping ratio which are finally needed by identification are mostly distributed in the frequency range corresponding to the pole, the frequency range corresponding to the pole of the transfer function can be screened out and used as the first frequency range of the main component, so that the calculation amount is reduced, and the calculation speed and the calculation efficiency are improved.
Since many unnecessary frequencies are included in the first frequency range corresponding to the pole, in order to narrow the frequency calculation range and increase the operation speed, the output data of the main component may be subjected to power spectrum analysis to obtain the second frequency range corresponding to the main component.
And narrowing the frequency range of the first frequency range by using the obtained second frequency range to obtain a frequency iteration range, so that the calculation amount is reduced, and the complexity of operation is reduced.
S14: and calculating the amplitude corresponding to each frequency in the frequency iteration range, acquiring the maximum amplitude, the target frequency corresponding to the maximum amplitude and a target pole, and calculating the damping ratio of the main component through a preset formula.
The above mentioned predetermined formula is
Wherein p is the target pole, ξ is the damping ratio, real (p) is the real part of the target pole p, and imag (p) is the imaginary part of the target pole p.
After obtaining the frequency iteration range, calculating the amplitude corresponding to each frequency in the frequency iteration range, selecting the maximum amplitude from the calculated amplitudes, and obtaining the frequency corresponding to the maximum amplitude, wherein the frequency is the frequency finally required for identification, namely the target frequency, and the pole corresponding to the maximum amplitude is the target pole p.
After the target pole p is acquired, pass
The damping ratio of the primary component is calculated to obtain the damping ratio that is ultimately desired for identification. Where ξ represents the damping ratio, real (p) represents the real part of the target pole p, and imag (p) represents the imaginary part of the target pole p.
The accuracy of distinguishing the main components can be improved through the mode, so that the main components of the wind generating set system can be effectively monitored, faults can be predicted in advance according to the frequency and the damping ratio of the main components which are accurately distinguished, the wind generating set system can be timely checked and maintained before the faults occur, the occurrence rate of the faults of the wind generating set is reduced, and the stability and the operation reliability of the wind generating set system are improved.
According to the technical scheme, the nonlinear fan model is established in advance through nonlinear system identification, so that the established fan model is closer to the characteristic of the wind power generation unit system. The acquired input data and output data of the main components of the wind turbine generator system are respectively used as the input quantity and the output quantity of the wind turbine model, and the transfer function of the main components is calculated after the model parameters of the wind turbine model are calculated, so that the condition simplification and the idealization do not exist in the process of calculating the transfer function. Then, a first frequency range corresponding to the pole is obtained by calculating the pole of the transfer function, and the first frequency range is narrowed by using a second frequency range obtained when the output data of the main component is subjected to power spectrum analysis, so that a frequency iteration range is obtained. After the frequency iteration range is obtained, the amplitude corresponding to each frequency in the frequency iteration range is calculated, the maximum amplitude, the target frequency corresponding to the maximum amplitude and the target pole are obtained, the damping ratio of the main component is calculated through the real part and the imaginary part of the target pole, the accuracy of identifying the frequency and the damping ratio of the main component can be improved through the identification method, and the identification method is simple and easy to operate and has low calculated amount.
According to the method for identifying the frequency and the damping ratio of the main components of the wind generating set, the main components can be a transmission chain or a tower;
the input data of the transmission chain is the torque of the generator, and the output data is the rotating speed of the generator;
the input data of the tower is the blade pitch angle and the output data is the tower speed.
The wind generating set system mentioned above may be specifically a variable speed variable pitch wind generating set system, and its specific structure may refer to fig. 2, which shows a schematic structural diagram of the variable speed variable pitch wind generating set system provided in the embodiment of the present invention, and its main components may include a transmission chain and a tower, that is, torque to rotational speed, and a blade pitch angle to tower speed may be identified respectively.
For the drive train or tower, the wind power generating set system can be seen as a non-linear SISO (Single Input Single Output) system. That is, when identifying the drive train, the corresponding input data is the generator torque TgAnd the output data is the rotating speed omega of the generator. When the tower is identified, the corresponding input data is the blade pitch angle β, and the output data is the tower speed v. In identifying the drive train or the tower, the excitation signal used for identification may be a pseudo-random function. Specifically, reference may be made to fig. 3, which shows a schematic structural diagram for identifying the frequency and damping ratio of the transmission chain or the tower according to an embodiment of the present invention, where T isgref、Ωgref、Ωg、βgrefRespectively representing torque given, rotational speed feedback, blade pitch angle given.
Of course, other types of wind turbine generator systems may be identified, and the primary components are not limited to the drive chain or tower, but may also be a gearbox, etc.
In the method for identifying the frequency and the damping ratio of the main components of the wind generating set provided by the embodiment of the invention, the fan model can be specifically an extended autoregressive moving average model: a (q)-1)y(k)＝B(q-1)u(k)+C(q-1)e(k)；
Wherein the content of the first and second substances,
q-1for the backward shift operator, k is the input number, anIs a polynomial A (q)-1) Parameter value of (a), bnIs a polynomial B (q)-1) Parameter value of cnIs a polynomial C (q)-1) N is the model order, y (k) is the k-th output quantity, u (k) is the k-th input quantity, and e (k) is the k-th noise signal.
The fan Model established by the nonlinear system identification can be ARMAX (extended Auto-Regressive Moving Average Model): a (q)-1)y(k)＝B(q-1)u(k)+C(q-1) e (k), which is labeled as formula (1). Wherein the content of the first and second substances,
q-1is a backshifting operator, which is related to k-1, k is the number of inputs, which is related to the acquisition instant, anIs a polynomial A (q)-1) Parameter value of (a), bnIs a polynomial B (q)-1) Parameter value of cnIs a polynomial C (q)-1) N is the model order, y (k) is the k-th output quantity, i.e. the output data of the main part acquired at the k time, u (k) is the k-th input quantity, i.e. the input data of the main part acquired at the k time, and e (k) is the k-th noise signal.
The ARMAX model is relatively attached to the motion rule of main components of the wind generating set system, and the identification accuracy can be improved when the frequency and the damping ratio are identified. Of course, other models may be used as the fan Model, such as an ARM (Auto-Regressive Model) Model.
The method for identifying the frequency and the damping ratio of the main components of the wind generating set, provided by the embodiment of the invention, comprises the following steps of calculating model parameters of a fan model, and calculating a transfer function of the main components according to the fan model:
deforming the extended autoregressive moving average model to obtain a deformation formula y (k) ═ a1y(k-1)-...-any(k-n)+b1u(k-1)+...+bnu(k-1)+c1e(k-1)+...+cne(k-n)；
Introducing vectors
And obtaining a recursion formula of theta by using a recursion least square method according to the vector:
calculating model parameter a in deformation formula by recursion formula and theta (0) and P (0)i、bi、ci，i＝1,2...n；
And (5) performing Laplace transform on y (k) in the deformation formula: y(s) ═ L [ y (k)]And performing a Laplace transform on u (k): u(s) ═ L [ u (k)]Calculating the transfer function of the main part through Y(s) and U(s)
Transforming the ARMAX model to obtain a deformation formula y (k) ═ a1y(k-1)-...-any(k-n)+b1u(k-1)+...+bnu(k-1)+c1e(k-1)+...+cne (k-n), which is labeled as formula (2).
Based on RLS (Recursive Least Square)e, recursive least squares) calculation of the model parameter a in equation (2)i、bi、ciN, i ═ 1,2. The implementation process is as follows:
introducing a vector according to the obtained deformation formula:
and labeled as formula (3), formula (3) may be rewritten as formula (4):
wherein the content of the first and second substances,
and R is a positive definite constant matrix.
Order to
And mark it as formula (5), then
By the formula (4) can be obtained
And labeled as formula (6).
Formula (7) is derived from formula (5) and formula (6):
the least squares estimate for time k can be expressed as:
the above equation is labeled as equation (8). Wherein the content of the first and second substances,
this is labeled as formula (9).
Formula (10) can be obtained by inverse theorem of formula (5) and the matrix:
formula (11) can be obtained by bringing formula (10) into formula (9):
formula (12) is derived from formula (10) and formula (11):
by summing equations (8), (11), and (12), the recurrence equation for θ can be expressed as:
When the input data and the output data of the main component are collected for the first time, initial values theta (0), P (0), the model order of the ARMAX model and the number N of times of collecting the input data and the output data are set. K (k), p (k), and then θ (k) are calculated using equation (13). As can be seen from the equation (3), θ (k) is related to the model parameter ai、bi、ciN, i-1, 2. Therefore, after calculating θ (k), the model parameter a can be obtainedi、bi、ci，i＝1,2...n。
After calculating the model parameters, the output quantity y (k) and the input quantity u (k) in the formula (2) are subjected to the Laplace transform, and Y(s) is made to be L [ y (k)]，U(s)＝L[u(k)]Then the transfer function of the main component can be calculated
This is labeled as formula (14). When the zero and the pole of the transfer function are calculated according to equation (14), the transfer function may be converted into a zero-pole form so that the zero and the pole of the transfer function can be intuitively obtained.
The structural schematic diagram for identifying the frequency and the damping ratio of the transmission chain or the tower of the wind turbine generator set based on the RLS can be specifically seen in fig. 4. Based on RLS, the model parameters can be conveniently obtained, and the sum of squares of errors between the obtained model parameters and actual data is minimized, so that the errors are reduced, and the identification accuracy is improved. Of course, in addition to calculating the model parameters by RLS, the model parameters may also be calculated by a neural network algorithm or the like.
The method for identifying the frequency and the damping ratio of the main components of the wind generating set provided by the embodiment of the invention is used for carrying out power spectrum analysis on the output data of the main components, and can comprise the following steps:
and carrying out power spectrum analysis on the output data of the main component by using an average periodogram method.
The output data (generator speed or tower speed) of the main components of the wind generating set system can be subjected to power spectrum analysis by using an average periodogram method, and a better power estimation value can be obtained by using the method. The implementation process is specifically as follows (the generator speed is taken as an example here for explanation):
dividing n observation data of the generator rotating speed value x (n) into K sections with the length of M, and overlapping M/2 observation data between two adjacent sections.
After the division, each piece of observation data is windowed. Accordingly, the observed data of the ith segment can be expressed as
s.t.0. ltoreq. n.ltoreq.M-1, 0. ltoreq. i.ltoreq.K-1, which is denoted as formula (15). Where ω (n) is a window function including, but not limited to, rectangular window, Hamming window, triangular window.
Computing x using FFT (Fast Fourier transform) algorithmi(n) L-point discrete fourier transform, yielding equation (16):
s.t.0-K is less than or equal to L-1, and i is more than or equal to 0 and less than or equal to K-1. If M < L, then at xi(n) is supplemented with L-M zeros.
Calculation of the periodogram S by equation (16)i(k)＝|Xi(k)|2，s.t.0≤k≤L-1,0≤i.ltoreq.K-1, which is marked as formula (17).
Calculating the average value of the K-section periodic diagram, thereby obtaining the estimated value of the power spectrum of the rotating speed of the generator as follows:
s.t.0. ltoreq. k.ltoreq.L-1, which is marked as formula (18). Wherein the content of the first and second substances,
and (3) obtaining a power spectrum estimated value according to the formula (18), recording the frequency corresponding to each peak in the power spectrum estimated value, wherein the frequency range formed by the frequencies is the second frequency range corresponding to the transmission chain. That is, the power spectrum analysis is performed by the average periodogram method, and then the second frequency range corresponding to the main component can be obtained from the obtained power spectrum estimation value.
An embodiment of the present invention further provides a device for identifying a frequency and a damping ratio of a main component of a wind turbine generator system, please refer to fig. 5, which shows a schematic structural diagram of the device for identifying a frequency and a damping ratio of a main component of a wind turbine generator system according to an embodiment of the present invention, and the device may include:
an obtaining module 11, configured to: acquiring input data and output data of main components of a wind generating set system, and respectively using the input data and the output data as input quantity and output quantity of a fan model established by nonlinear system identification in advance;
a first calculation module 12 for: calculating model parameters of the fan model, and calculating a transfer function of a main component according to the fan model;
a second calculation module 13 configured to: calculating a pole of the transfer function to obtain a first frequency range of the main component corresponding to the pole, performing power spectrum analysis on output data of the main component to obtain a second frequency range corresponding to the main component, and reducing the frequency range of the first frequency range by using the second frequency range to obtain a frequency iteration range;
a third calculation module 14 for: each within an iteration range of the calculation frequencyObtaining the maximum amplitude, the target frequency corresponding to the maximum amplitude and the target pole p, and passing through
And calculating the damping ratio of the main part, wherein xi is the damping ratio, real (p) is the real part of the target pole p, and imag (p) is the imaginary part of the target pole p.
An embodiment of the present invention further provides a device for identifying a frequency and a damping ratio of a main component of a wind turbine generator system, please refer to fig. 6, which shows a schematic structural diagram of the device for identifying a frequency and a damping ratio of a main component of a wind turbine generator system according to an embodiment of the present invention, and the device may include:
a memory 21 for storing a computer program;
and the processor 22 is used for implementing the steps of any one of the methods for identifying the frequency and the damping ratio of the main components of the wind generating set when executing the computer program.
The embodiment of the invention also provides a computer readable storage medium, wherein a computer program is stored on the computer readable storage medium, and when the computer program is executed by a processor, the steps of the method for identifying the frequency and the damping ratio of the main component of the wind generating set are realized.
For a description of relevant parts in the device, the equipment and the computer-readable storage medium for identifying the frequency and the damping ratio of the main component of the wind generating set provided by the embodiment of the present invention, reference is made to the detailed description of corresponding parts in the method for identifying the frequency and the damping ratio of the main component of the wind generating set provided by the embodiment of the present invention, and details are not repeated herein.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Furthermore, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include elements inherent in the list. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element. In addition, parts of the above technical solutions provided in the embodiments of the present invention that are consistent with the implementation principles of the corresponding technical solutions in the prior art are not described in detail, so as to avoid redundant description.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (8)
1. A method for identifying the frequency and the damping ratio of main components of a wind generating set is characterized by comprising the following steps:
acquiring input data and output data of main components of a wind generating set system, and respectively using the input data and the output data as input quantity and output quantity of a fan model established in advance through nonlinear system identification; the main components comprise blades, a tower, a transmission chain, a gear box and a variable pitch system;
calculating model parameters of the fan model, and calculating a transfer function of the main component according to the fan model;
calculating a pole of the transfer function to obtain a first frequency range of the main component corresponding to the pole, performing power spectrum analysis on output data of the main component to obtain a second frequency range corresponding to the main component, and reducing the frequency range of the first frequency range by using the second frequency range to obtain a frequency iteration range;
calculating the amplitude corresponding to each frequency in the frequency iteration range to obtain the maximum amplitude,And a target frequency and a target pole p corresponding to said maximum amplitude by
Calculating the damping ratio of the main part, wherein ξ is the damping ratio, real (p) is the real part of the target pole p, and imag (p) is the imaginary part of the target pole p.
2. The method for identifying the frequency and damping ratio of the main components of the wind generating set according to claim 1, wherein when the main component is a transmission chain or a tower;
the input data of the transmission chain is the torque of the generator, and the output data is the rotating speed of the generator;
the input data of the tower is a blade pitch angle, and the output data is a tower speed.
3. The method for identifying the frequency and the damping ratio of the main components of the wind generating set according to claim 2, wherein the wind turbine model is specifically an extended autoregressive moving average model: a (q)-1)y(k)＝B(q-1)u(k)+C(q-1)e(k)；
Wherein the content of the first and second substances,
q-1for the backward shift operator, k is the input number, anIs a polynomial A (q)-1) Parameter value of (a), bnIs a polynomial B (q)-1) Parameter value of cnIs a polynomial C (q)-1) N is the model order, y (k) is the k-th output quantity, u (k) is the k-th input quantity, and e (k) is the k-th noise signal.
4. The method for identifying the frequency and the damping ratio of the main components of the wind generating set according to claim 3, wherein calculating model parameters of the wind turbine model and calculating the transfer function of the main components according to the wind turbine model comprises:
for the extensionDeforming the autoregressive moving average model to obtain a deformation formula y (k) ═ a1y(k-1)-...-any(k-n)+b1u(k-1)+...+bnu(k-1)+c1e(k-1)+...+cne(k-n)；
Introducing vectors
According to the vector, a recursive formula of theta is obtained by utilizing a recursive least square method:
calculating a model parameter a in the deformation formula through the recursion formula and theta (0) and P (0)i、bi、ciN, i ═ 1,2.. n; wherein, theta (0) and P (0) are set initial values, theta (0) is an initial value corresponding to theta (k), and P (0) is an initial value corresponding to P (k);
performing a Laplace transform on y (k) in the warping formula: y(s) ═ L [ y (k)]And performing a Laplace transform on u (k): u(s) ═ L [ u (k)]Calculating the transfer function of the main part through Y(s) and U(s)
5. The method for identifying the frequency and the damping ratio of the main components of the wind generating set according to claim 1, wherein the step of performing power spectrum analysis on the output data of the main components comprises the following steps:
and carrying out power spectrum analysis on the output data of the main component by using an average periodogram method.
6. The utility model provides a wind generating set essential element frequency and damping ratio's identification device which characterized in that includes:
an acquisition module to: acquiring input data and output data of main components of a wind generating set system, and respectively using the input data and the output data as input quantity and output quantity of a fan model established in advance through nonlinear system identification; the main components comprise blades, a tower, a transmission chain, a gear box and a variable pitch system;
a first computing module to: calculating model parameters of the fan model, and calculating a transfer function of the main component according to the fan model;
a second calculation module to: calculating a pole of the transfer function to obtain a first frequency range of the main component corresponding to the pole, performing power spectrum analysis on output data of the main component to obtain a second frequency range corresponding to the main component, and reducing the frequency range of the first frequency range by using the second frequency range to obtain a frequency iteration range;
a third calculation module to: calculating the amplitude corresponding to each frequency in the frequency iteration range, obtaining the maximum amplitude, and the target frequency and the target pole p corresponding to the maximum amplitude, and processing the frequency iteration range by the steps of
Calculating the damping ratio of the main part, wherein ξ is the damping ratio, real (p) is the real part of the target pole p, and imag (p) is the imaginary part of the target pole p.
7. The utility model provides an equipment of discerning of wind generating set essential element frequency and damping ratio which characterized in that includes:
a memory for storing a computer program;
a processor for implementing the steps of the method for identifying the frequency and damping ratio of the main components of a wind park according to any one of claims 1 to 5 when executing said computer program.
8. A computer-readable storage medium, characterized in that a computer program is stored on the computer-readable storage medium, which computer program, when being executed by a processor, carries out the steps of the method for identifying the frequency and damping ratio of the main components of a wind park as claimed in any one of claims 1 to 5.
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