Wind farm harmonic instability sensitivity calculation method and system considering different voltage levels

Abstract

The invention discloses a method and system for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels, and relates to the technical field of frequency domain modal element sensitivity analysis. The method comprises: establishing a wind farm node admittance matrix corresponding to each wind farm equivalent circuit model according to each wind farm equivalent circuit model, and obtaining the determinant of each wind farm node admittance matrix, and obtaining the inherent mode of each wind farm equivalent circuit model; performing partial derivative processing on the wind farm node admittance matrix of the inherent mode to obtain the sensitivity matrix of the wind farm equivalent circuit model; based on the sensitivity matrix of each wind farm equivalent circuit model, calculating the component frequency domain modal sensitivity of each component under the corresponding inherent mode; through the frequency domain modal element sensitivity analysis method, the stability of the system can be judged through the system inherent mode, and the sensitivity can also be directly calculated through the inherent mode, and the influence of component parameters on system damping and harmonic frequency can be quantitatively analyzed.

Description

Technical Field

[0001] The present invention relates to the technical field of frequency domain modal element sensitivity analysis, and more specifically, to a method and system for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels. Background Art

[0002] With the implementation of the "dual carbon" strategic goal, the large-scale development of wind power has become an important direction for the transformation of energy structure and efficient and low-carbon development; in scenarios such as "deep sea" and "Sago Desert", most wind farms are connected to the grid through 35kV collector lines, 220kV long-distance transmission lines and multiple transformers. When the impedance on the grid side is large, the system may present weak grid characteristics; since the collector lines and transmission lines are mostly over 10 kilometers, the distributed capacitance effect cannot be ignored, and it is easy to couple with the inductive elements on the wind farm and the grid side, which may cause the wind farm to have multiple resonance points in the wide frequency domain, causing harmonic instability problems. However, most of the existing studies on harmonic instability of wind farms use line concentrated parameter models, which cannot accurately describe the high-frequency characteristics of the lines, and the solved wind farm stability results are inaccurate; and the current research on the distributed parameter effect only considers the distributed parameter effect of the collector line, ignoring the influence of the long-distance transmission line on the ground capacitance; in addition, it has not yet been possible to quantitatively solve the degree of influence of the changes in the parameters of each component of the wind farm on the harmonic instability. Summary of the invention

[0003] The object of the present invention is to provide a method and system for calculating the harmonic instability sensitivity of a wind farm taking into account different voltage levels, so as to solve the problems existing in the above-mentioned background technology.

[0004] The above technical objectives of the present invention are achieved through the following technical solutions:

[0005] In a first aspect, the present application provides a method for calculating the harmonic instability sensitivity of a wind farm taking into account different voltage levels, comprising the following specific steps:

[0006] Using the Norton equivalent circuit method, multiple wind farm equivalent circuit models taking into account the distribution parameters of cables at different voltage levels are established;

[0007] According to each wind farm equivalent circuit model, a wind farm node admittance matrix corresponding to each model is established, and the determinant of each wind farm node admittance matrix is ​​obtained;

[0008] The complex hyperbolic functions of each determinant are converted into exponential functions, and then the exponential functions of each determinant are converted into rational functions using the Pade approximation method, and each determinant converted into a rational function is solved to obtain the inherent mode of each wind farm equivalent circuit model;

[0009] For each wind farm equivalent circuit model, the inherent mode is used to obtain the partial derivative of the wind farm node admittance matrix to obtain the sensitivity matrix of the wind farm equivalent circuit model;

[0010] Based on the sensitivity matrix of each wind farm equivalent circuit model, the frequency domain modal sensitivity of each component in the corresponding natural mode is calculated.

[0011] The beneficial effects of the present invention are as follows: in this scheme, firstly, impedance models of various wind farms taking into account line distribution parameters, namely, equivalent circuit models of wind farms, are established; secondly, based on the proposed method, the system stability and the quantitative influence of each component on harmonic instability are directly judged through the inherent mode, and the influence of different line models on harmonic stability is studied, namely, by calculating the sensitivity of each component in the equivalent circuit model of each wind farm; finally, the influence of component parameters on system damping and harmonic frequency is quantitatively analyzed.

[0012] In this scheme, the influence of the parameter changes of each wind farm component on the harmonic instability is quantitatively solved. That is, the frequency domain modal component sensitivity analysis method can be used to judge the stability of the system through the system inherent mode, and the sensitivity can be directly calculated through the inherent mode. In addition, the influence of component parameters on the system damping and harmonic frequency can be quantitatively analyzed.

[0013] Based on the above technical solution, the present invention can also be improved as follows.

[0014] Furthermore, the inherent modes of the above-mentioned wind farm equivalent circuit models are specifically:

[0015] S i =σ i +jω i ;

[0016] In the formula, S i represents the inherent mode of wind farm equivalent circuit model i, σ i represents the attenuation coefficient of the wind farm equivalent circuit model i, j represents the imaginary unit, ω i Represents the angular frequency of wind farm equivalent circuit model i.

[0017] Furthermore, the sensitivity matrix of the above wind farm equivalent circuit model is specifically:

[0018]

[0019] In the formula, S g，jk represents the element in the jth row and kth column of the sensitivity matrix, S i represents the inherent mode of wind farm equivalent circuit model i, y jk Represents the element in the j-th row and k-th column of the wind farm node admittance matrix of the wind farm equivalent circuit model.

[0020] Furthermore, the frequency domain modal sensitivity of each component in the corresponding natural mode is specifically:

[0021]

[0022] In the formula, represents the frequency domain modal sensitivity of component y, S g，jk represents the element in the jth row and kth column of the sensitivity matrix, y jk Represents the element in the j-th row and k-th column of the wind farm node admittance matrix of the wind farm equivalent circuit model.

[0023] Furthermore, the above method also includes:

[0024] The frequency domain modal sensitivity of each component in each wind farm equivalent circuit model is normalized as follows:

[0025]

[0026] In the formula, S g1 represents the normalized component frequency domain modal sensitivity of component y, It represents the component frequency domain modal sensitivity of component y without normalization.

[0027] Make the frequency domain modal sensitivity of each component comparable.

[0028] Furthermore, the above method also includes:

[0029] According to the connection relationship between each component and each node in the wind farm node admittance matrix, the frequency domain modal sensitivity of each component is classified as follows:

[0030]

[0031] In the formula, represents the frequency domain modal sensitivity of component y, S g，jj represents the element in the jth row and jth column of the sensitivity matrix, S g，kk represents the element in the kth row and kth column of the sensitivity matrix, S g，jk represents the element in the jth row and kth column of the sensitivity matrix, S g，kj Represents the element in the kth row and jth column of the sensitivity matrix.

[0032] Furthermore, the above method also includes:

[0033] The partial derivative of the internal parameters of the component is obtained to obtain the parameter frequency domain modal sensitivity of the component, which is:

[0034]

[0035] In the formula, S g2 represents the parameter frequency domain modal sensitivity of the component, represents the frequency domain modal sensitivity of component y, and α represents the internal parameters of the component.

[0036] In a second aspect, the present application provides a wind farm harmonic instability sensitivity calculation system taking into account different voltage levels, which is applied to any wind farm harmonic instability sensitivity calculation method taking into account different voltage levels in the first aspect, including:

[0037] The first module is used to establish multiple wind farm equivalent circuit models taking into account the distribution parameters of cables of different voltage levels by using the Norton equivalent circuit method;

[0038] The second module is used to establish the wind farm node admittance matrix corresponding to each model according to the equivalent circuit model of each wind farm, and obtain the determinant of each wind farm node admittance matrix;

[0039] The third module is used to convert the complex hyperbolic function of each determinant into an exponential function, and then use the Pade approximation method to convert the exponential function of each determinant into a rational function, and solve each determinant converted into a rational function to obtain the inherent mode of each wind farm equivalent circuit model;

[0040] The fourth module is used to calculate the partial derivative of the wind farm node admittance matrix of the inherent mode for each wind farm equivalent circuit model to obtain the sensitivity matrix of the wind farm equivalent circuit model;

[0041] The fifth module is used to calculate the frequency domain modal sensitivity of each component in the corresponding natural mode based on the sensitivity matrix of each wind farm equivalent circuit model.

[0042] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any one of the methods in the first aspect when executing the computer program.

[0043] In a fourth aspect, the present application provides a non-transitory computer-readable storage medium, which stores computer instructions, and the computer instructions enable a computer to execute any one of the methods in the first aspect.

[0044] Compared with the prior art, the present invention has at least the following beneficial effects:

[0045] In this application, firstly, impedance models of various wind farms taking into account the line distribution parameters, namely, the wind farm equivalent circuit model, are established; secondly, based on the proposed method, the system stability and the quantitative influence of each component on the harmonic instability are directly judged through the inherent mode, and the influence of different line models on the harmonic stability is studied, namely, by calculating the sensitivity of each component in the equivalent circuit model of each wind farm; finally, the influence of component parameters on system damping and harmonic frequency is quantitatively analyzed.

[0046] In the present application, the degree of influence of parameter changes of each component of the wind farm on harmonic instability is quantitatively solved, that is, the frequency domain modal component sensitivity analysis method can be used to judge the stability of the system through the system inherent mode, and the sensitivity can be directly calculated through the inherent mode, and the influence of component parameters on system damping and harmonic frequency can be quantitatively analyzed; at the same time, the component frequency domain modal sensitivity of each component in the equivalent circuit model of each wind farm is normalized to make the component frequency domain modal sensitivity of each component comparable.

[0047] In the present application, a new method for harmonic instability sensitivity analysis of wind farms based on Pade approximation can not only judge the system stability through the inherent mode, but also analyze the sensitivity of component parameters when harmonic instability occurs, thus solving the limitation of impedance analysis method in judging harmonic stability; the new method for harmonic instability sensitivity analysis of wind farms taking into account the distribution parameters of cables of different voltage levels can directly solve the influence of the changes in the parameters of each component of the wind farm on the harmonic instability through the inherent mode, and give the dominant factors of harmonic instability, thus effectively making up for the deficiency of the existing harmonic instability analysis that cannot quantitatively solve the sensitivity of each component parameter of the wind farm; the new method for harmonic instability sensitivity analysis can quantitatively analyze the influence of component parameters on system damping and harmonic frequency respectively, thus filling the gap that the eigenvalue sensitivity method cannot analyze the direct influence of component parameters on harmonic instability. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0049] Figure 1 A method flow chart of a calculation method in an embodiment of the present invention;

[0050] Figure 2 A connection diagram of a computing system in an embodiment of the present invention;

[0051] Figure 3 A schematic diagram of the connection of electronic equipment in an embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram of comparative analysis in an embodiment of the present invention;

[0053] FIG5(a) is a diagram showing the PCC point voltage U in verifying the correctness of harmonic instability analysis in an embodiment of the present invention. pcc The time domain waveform diagram of

[0054] FIG5( b ) is a diagram of a harmonic voltage spectrum for verifying the correctness of harmonic instability analysis in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0056] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0058] In the description of the embodiments of the present invention, "plurality" means at least 2.

[0059] Embodiment 1: This embodiment provides a method for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels, such as Figure 1 As shown, the specific steps include:

[0060] S1. Use the Norton equivalent circuit method to establish multiple wind farm equivalent circuit models that take into account the distribution parameters of cables at different voltage levels.

[0061] Among them, the Norton equivalent circuit simplifies the complex network into a circuit consisting of an equivalent current source and an equivalent resistor in parallel. In this way, circuit models corresponding to wind farms with multiple cable distribution parameters of different voltage levels can be established.

[0062] S2. Establishing the wind farm node admittance matrix corresponding to each model according to each wind farm equivalent circuit model, and obtaining the determinant of each wind farm node admittance matrix.

[0063] Among them, the node admittance matrix can be used to represent the matrix of the admittance relationship between nodes in the circuit; in the power system and microwave network, the node admittance matrix is ​​widely used to describe the electrical characteristics between each node; in the wind farm involved in this embodiment, the node admittance matrix can describe the parameters of each component in the wind farm and the operation model of the circuit; by calculating the admittance matrix, the branch matrix and drive matrix of the circuit can be obtained, and then the power system switch and short-circuit current calculation, line reactance and voltage distribution calculation, etc. can be performed.

[0064] S3. Convert the complex hyperbolic functions of each determinant into an exponential function, convert the exponential functions of each determinant into a rational function using the Pade approximation method, and solve each determinant converted into a rational function to obtain the inherent mode of each wind farm equivalent circuit model.

[0065] Among them, the complex hyperbolic function of the determinant det(Y(s)) of the node admittance matrix is ​​converted into an exponential function, where det is the abbreviation of determinant and is the definition of the determinant, that is, an n-order matrix, then its determinant is a series of sums, and each addition element is the multiplication of n matrix elements; then the exponential function is converted into a rational function using the Pade approximation to obtain the intrinsic mode of the determinant; specifically, first, the intrinsic mode S = σ + jω is substituted into the exponential function, and a suitable boundary σ is selected L , σ R ; When σ<σ L Or σ>σ R When |cosh(γl)|≈|cosh(γl)|, all hyperbolic function terms in the determinant of the node admittance matrix can be reduced to rational functions.

[0066] Furthermore, when σ L <σ<σ R When the complex hyperbolic function in the transcendental equation is transformed into an exponential function, and then the exponential function is transformed into a rational function using the Pade approximation, and then the zeros of the determinant are solved.

[0067] The zero point of the determinant det(Y(s)) is finally solved by the above two methods, which is the inherent mode of the wind farm equivalent circuit model; optionally, the inherent modes of the above wind farm equivalent circuit models can be expressed as:

[0068] S i =σ i +jω i ;

[0069] In the formula, S i represents the inherent mode of wind farm equivalent circuit model i, σ i represents the attenuation coefficient of the wind farm equivalent circuit model i, j represents the imaginary unit, ωi Represents the angular frequency of wind farm equivalent circuit model i.

[0070] S4. For each wind farm equivalent circuit model, the inherent mode is used to obtain the partial derivative of the wind farm node admittance matrix to obtain the sensitivity matrix of the wind farm equivalent circuit model.

[0071] Among them, the eigenvalue sensitivity method can be used to obtain the partial derivative of the intrinsic mode with respect to the node admittance matrix elements to obtain the sensitivity matrix based on the intrinsic mode; optionally, the sensitivity matrix of the above wind farm equivalent circuit model is specifically:

[0072]

[0073] In the formula, S g，jk represents the element in the jth row and kth column of the sensitivity matrix, S i represents the inherent mode of wind farm equivalent circuit model i, y jk Represents the element in the j-th row and k-th column of the wind farm node admittance matrix of the wind farm equivalent circuit model.

[0074] Specifically, if a small perturbation occurs in the system, making the element y jk and the intrinsic mode S i The offset Δy occurs jk and ΔS i , the value of the determinant remains unchanged, then: Since det(Y(S i ))In S i Nearby analysis, the first-order Taylor expansion of the above formula can be obtained in, because Then we can deduce:

[0075] Therefore, the sensitivity of the eigenmode with respect to the element admittance y is:

[0076]

[0077] S5. Based on the sensitivity matrix of each wind farm equivalent circuit model, the frequency domain modal sensitivity of each component in the corresponding natural mode is calculated.

[0078] Optionally, the frequency domain modal sensitivity of each component in the corresponding natural mode is specifically:

[0079]

[0080] In the formula, represents the frequency domain modal sensitivity of component y, S g，jkrepresents the element in the jth row and kth column of the sensitivity matrix, y jk Represents the element in the j-th row and k-th column of the wind farm node admittance matrix of the wind farm equivalent circuit model.

[0081] Optionally, the above method further includes:

[0082] According to the connection relationship between each component and each node in the wind farm node admittance matrix, the frequency domain modal sensitivity of each component is classified as follows:

[0083]

[0084] In the formula, represents the frequency domain modal sensitivity of component y, S g，jj represents the element in the jth row and jth column of the sensitivity matrix, S g，kk represents the element in the kth row and kth column of the sensitivity matrix, S g，jk represents the element in the jth row and kth column of the sensitivity matrix, S g，kj Represents the element in the kth row and jth column of the sensitivity matrix.

[0085] Among them, the frequency domain modal sensitivity can reflect the influence of the change of network component parameters on the damping and frequency of any mode of interest. By adjusting the component parameters with the greatest sensitivity, the mode damping can be most effectively increased with the minimum adjustment of the component parameters, thereby achieving harmonic instability suppression; in order to make the frequency domain sensitivities of each component comparable, the frequency domain modal sensitivities of the components are normalized; optionally, the above method also includes:

[0086] The frequency domain modal sensitivity of each component in each wind farm equivalent circuit model is normalized as follows:

[0087]

[0088] In the formula, S g1 represents the normalized component frequency domain modal sensitivity of component y, represents the frequency domain modal sensitivity of the component y that has not been normalized. The above method further includes: taking partial derivatives of the internal parameters of the component to obtain the frequency domain modal sensitivity of the parameters of the component, specifically:

[0089]

[0090] In the formula, S g2 represents the parameter frequency domain modal sensitivity of the component, represents the frequency domain modal sensitivity of component y, and α represents the internal parameters of the component.

[0091] Specifically, the new method of harmonic instability sensitivity analysis of wind farms based on Pade approximation can not only judge the system stability through the inherent mode, but also analyze the sensitivity of component parameters when harmonic instability occurs, thus solving the limitation of impedance analysis method in judging harmonic stability; the new method of harmonic instability sensitivity analysis of wind farms taking into account the distribution parameters of cables of different voltage levels can directly solve the influence of the changes in the parameters of each component of the wind farm on the harmonic instability through the inherent mode, and give the dominant factors of harmonic instability, thus effectively making up for the deficiency of the existing harmonic instability analysis that cannot quantitatively solve the sensitivity of each component parameter of the wind farm; the new method of harmonic instability sensitivity analysis can quantitatively analyze the influence of component parameters on system damping and harmonic frequency respectively, thus filling the gap that the eigenvalue sensitivity method cannot analyze the direct influence of component parameters on harmonic instability.

[0092] The following is a further detailed explanation with examples. Through Pade approximation, the hyperbolic function in the determinant of the system node admittance matrix is ​​approximated as a rational fraction to solve the inherent mode of the system. When the lengths of the 35kV and 220kV lines are 20km and 50km respectively, in order to analyze the impact of different models on the system stability, all lines are replaced with line series impedance or concentrated single π model for comparative analysis, as shown below. Figure 4 As shown by Figure 4 It can be seen that, on the one hand, when comparing the mode distribution when the system adopts the line distributed parameter model and the concentrated single π model, the latter will miss the high-frequency mode of the system; on the other hand, when the system considers the distributed parameter model, the concentrated single π model and the series impedance model respectively, the mode damping and frequency are different. From the above, it can be seen that taking into account the line series impedance and the concentrated single π model cannot accurately analyze the harmonic amplification point and stability of the system.

[0093] Further, Figure 4 The medium and weak damping natural mode is analyzed, and the influence of the unit length resistance, inductance and capacitance of the 35kV collector line and 220kV transmission line on the natural mode is analyzed. The results are shown in Table 1. Finally, 1) verification Figure 4 The correctness of the harmonic instability analysis is shown in Figure 5 and Table 2, where Figure 5(a) is the PCC point voltage U pcc 5(b) is the time domain waveform of the harmonic voltage spectrum. By comparing the spectrum peak points in Figure 5(b) and the distribution of inherent modes in Table 2, the accuracy of the obtained harmonic amplification point can be verified, that is, the series impedance line model and the concentrated single π model cannot determine the harmonic amplification point and stability of the system within a wide frequency range; 2) verify the accuracy of the frequency domain modal sensitivity in Table 1, as shown in Table 3.

[0094] Table 1

[0095]

[0096] Table 2

[0097]

[0098] Table 3

[0099]

[0100]

[0101] Embodiment 2: The embodiment of the present application provides a wind farm harmonic instability sensitivity calculation system taking into account different voltage levels, which is applied to any wind farm harmonic instability sensitivity calculation method taking into account different voltage levels in Embodiment 1, such as Figure 2 As shown, including:

[0102] The first module is used to establish multiple wind farm equivalent circuit models taking into account the distribution parameters of cables of different voltage levels by using the Norton equivalent circuit method.

[0103] The second module is used to establish the wind farm node admittance matrix corresponding to each model according to the equivalent circuit model of each wind farm, and obtain the determinant of each wind farm node admittance matrix.

[0104] The third module is used to convert the complex hyperbolic functions of each determinant into an exponential function, and then use the Pade approximation method to convert the exponential functions of each determinant into a rational function, and solve each determinant converted into a rational function to obtain the inherent mode of each wind farm equivalent circuit model.

[0105] The fourth module is used to obtain the partial derivative of the wind farm node admittance matrix of the inherent mode for each wind farm equivalent circuit model to obtain the sensitivity matrix of the wind farm equivalent circuit model.

[0106] The fifth module is used to calculate the frequency domain modal sensitivity of each component in the corresponding natural mode based on the sensitivity matrix of each wind farm equivalent circuit model.

[0107] Embodiment 3: This embodiment of the present application provides an electronic device, such as Figure 3 As shown, it includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, any method in Embodiment 1 is implemented.

[0108] Embodiment 4: The embodiment of the present application provides a non-transitory computer-readable storage medium, which stores computer instructions, and the computer instructions enable a computer to execute any method in Embodiment 1.

[0109] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels, characterized in that: The specific steps include: Using the Norton equivalent circuit method, multiple wind farm equivalent circuit models taking into account the distribution parameters of cables at different voltage levels are established; According to each wind farm equivalent circuit model, a wind farm node admittance matrix corresponding to each model is established, and the determinant of each wind farm node admittance matrix is ​​obtained; Converting the complex hyperbolic function of each of the determinants into an exponential function, converting the exponential function of each of the determinants into a rational function using the Pade approximation method, and solving each of the determinants converted into the rational function to obtain the inherent mode of each wind farm equivalent circuit model; For each wind farm equivalent circuit model, performing partial derivative processing on the wind farm node admittance matrix using the inherent mode to obtain a sensitivity matrix of the wind farm equivalent circuit model; Based on the sensitivity matrix of each wind farm equivalent circuit model, the frequency domain modal sensitivity of each component in the corresponding natural mode is calculated.

2. The method for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels according to claim 1, characterized in that: The inherent modes of the equivalent circuit models of each wind farm are specifically: S i =σ i +jω i ; In the formula, S i represents the inherent mode of wind farm equivalent circuit model i, σ i represents the attenuation coefficient of the wind farm equivalent circuit model i, j represents the imaginary unit, ω i Represents the angular frequency of wind farm equivalent circuit model i.

3. The method for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels according to claim 2, characterized in that: The sensitivity matrix of the wind farm equivalent circuit model is specifically: In the formula, S g，jk represents the element in the jth row and kth column of the sensitivity matrix, S i represents the inherent mode of wind farm equivalent circuit model i, y jk Represents the element in the j-th row and k-th column of the wind farm node admittance matrix of the wind farm equivalent circuit model.

4. The method for calculating the harmonic instability sensitivity of a wind farm taking into account different voltage levels according to claim 3 is characterized in that: The component frequency domain modal sensitivity of each component in the corresponding natural mode is specifically: In the formula, represents the frequency domain modal sensitivity of component y, S g，jk represents the element in the jth row and kth column of the sensitivity matrix, y jk Represents the element in the j-th row and k-th column of the wind farm node admittance matrix of the wind farm equivalent circuit model.

5. The method for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels according to claim 4, characterized in that: The method further comprises: The frequency domain modal sensitivity of each component in each wind farm equivalent circuit model is normalized, specifically: In the formula, S g1 represents the normalized component frequency domain modal sensitivity of component y, It represents the component frequency domain modal sensitivity of component y without normalization.

6. The method for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels according to claim 4, characterized in that: The method further comprises: According to the connection relationship between each component and each node in the wind farm node admittance matrix, the frequency domain modal sensitivity of each component is classified as follows: In the formula, represents the frequency domain modal sensitivity of component y, S g，jj represents the element in the jth row and jth column of the sensitivity matrix, S g，kk represents the element in the kth row and kth column of the sensitivity matrix, S g，jk represents the element in the jth row and kth column of the sensitivity matrix, S g，kj Represents the element in the kth row and jth column of the sensitivity matrix.

7. The method for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels according to claim 4, characterized in that: The method further comprises: The partial derivative of the internal parameters of the component is obtained to obtain the parameter frequency domain modal sensitivity of the component, which is: In the formula, S g2 represents the parameter frequency domain modal sensitivity of the component, represents the frequency domain modal sensitivity of component y, and α represents the internal parameters of the component.

8. A system for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels, applied to the method for calculating the sensitivity of wind farm harmonic instability taking into account different voltage levels according to any one of claims 1 to 7, characterized in that: include: The first module is used to establish multiple wind farm equivalent circuit models taking into account the distribution parameters of cables of different voltage levels by using the Norton equivalent circuit method; The second module is used to establish the wind farm node admittance matrix corresponding to each model according to the equivalent circuit model of each wind farm, and obtain the determinant of each wind farm node admittance matrix; The third module is used to convert the complex hyperbolic function of each of the determinants into an exponential function, and then convert the exponential function of each determinant into a rational function by using the Pade approximation method, and solve each determinant converted into a rational function to obtain the inherent mode of each wind farm equivalent circuit model; The fourth module is used to perform partial derivative processing of the inherent mode on the wind farm node admittance matrix for each wind farm equivalent circuit model to obtain a sensitivity matrix of the wind farm equivalent circuit model; The fifth module is used to calculate the frequency domain modal sensitivity of each component in the corresponding natural mode based on the sensitivity matrix of each wind farm equivalent circuit model.

9. An electronic device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the method according to any one of claims 1 to 7 is implemented when the processor executes the computer program.

10. A non-transitory computer-readable storage medium, characterized in that: The non-transitory computer-readable storage medium stores computer instructions, which enable a computer to execute the method of any one of claims 1-7.

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