A method for identifying key components that cause broadband resonance

Abstract

The present invention provides a method for identifying key components that cause wideband resonance, comprising: determining network modal information; performing modal sensitivity analysis and modal frequency sensitivity analysis based on the network modal information, and classifying the modal sensitivity analysis results and modal frequency sensitivity analysis results by capacitive parameters or inductive parameters, respectively, and determining whether the modal sensitivity analysis result or modal frequency sensitivity analysis result corresponding to a component exceeds a set threshold. If not, the component is determined not to be a key component that causes resonance at the frequency; if exceeded, the component is determined to be a key component that causes resonance at the frequency. The present invention improves the calculation accuracy of modal sensitivity and simultaneously considers modal sensitivity and modal frequency sensitivity to clearly identify key components of resonance.

Description

Technical Field

[0001] The present invention relates to the technical field of analysis of broadband harmonic resonance in power systems, and in particular to a method for identifying key components causing broadband resonance. Background Art

[0002] With the rapid development of new power systems with a high proportion of renewable energy and power electronic equipment, the number of nonlinear elements in power systems has increased. This may interact with the reactive compensation devices in the system to cause harmonic resonance in the power system. Resonance problems can be analyzed using frequency sweeps or modal analysis. However, the resonance information obtained by frequency sweeps is too limited, so modal analysis is used to study the impact of various network components on resonance. As the number of loads and devices generating harmonics in power systems increases, it is necessary to develop a method for identifying key components for wideband harmonic resonance to understand the resonance characteristics of the power grid and to prevent and control resonance.

[0003] By using modal analysis to obtain the resonant frequency and the corresponding sensitivity matrix, we can further calculate the modal sensitivity of each network component at the corresponding resonant frequency, and then calculate the modal frequency sensitivity of each component. Existing modal sensitivity analysis and modal frequency sensitivity analysis can only roughly compare the sensitivity of each component to resonance and rank the sensitivity. They cannot quantitatively determine the specific key resonant components and lack an accurate basis for determining key resonant components. Summary of the Invention

[0004] The purpose of the present invention is to propose a method for identifying key components that cause wideband resonance, to solve the technical problem of how to improve the calculation accuracy of modal sensitivity, and to clearly determine the key components of resonance by considering modal sensitivity and modal frequency sensitivity.

[0005] On the one hand, a method for identifying key components causing broadband resonance is provided, comprising:

[0006] Determining network modal information, wherein the network modal information includes at least a resonant frequency and a sensitivity matrix corresponding thereto;

[0007] Performing modal sensitivity analysis and modal frequency sensitivity analysis based on the network modal information, and classifying the modal sensitivity analysis results and the modal frequency sensitivity analysis results according to capacitive parameters or inductive parameters, respectively, and determining the percentages within their respective categories to obtain classification results, wherein the modal sensitivity analysis includes the first-order derivative of modal admittance with respect to component parameters; the modal frequency sensitivity includes the derivatives of conductance and susceptance with respect to R, L, C, and frequency f in the RLC series branch model, and the first-order derivative of the resonant frequency with respect to component parameters;

[0008] According to the classification result, it is determined whether the percentage of the modal sensitivity analysis result or the modal frequency sensitivity analysis result corresponding to a certain component in the respective category exceeds the set threshold. If not, it is determined that the component is not the key component that causes resonance at the frequency; if exceeded, it is determined that the component is the key component that causes resonance at the frequency.

[0009] Preferably, determining the network modality information includes:

[0010] Determine the resonant frequency of the system using the following calculation formula:

[0011]

[0012] Where f represents the resonant frequency; Y represents the admittance matrix of the system; Λ represents the eigenvalue matrix of matrix Y; T represents the eigenvector matrix of matrix Y, recorded as the right eigenmatrix; L represents the inverse matrix of the eigenvector matrix T, recorded as the left eigenmatrix; if Y is of order n, the system admittance matrix at each frequency is diagonally decomposed, and the eigenvalues ​​in Λ are connected at the frequency points of the step size to obtain n curves. The frequency corresponding to the peak of the curve is the resonant frequency f, λ m represents the modal admittance, which is the smallest of all eigenvalues ​​of Λ at the resonant frequency f; m represents the mode number.

[0013] And, the sensitivity matrix corresponding to the resonant frequency is determined according to the following calculation formula:

[0014]

[0015] Where m represents the mode number; S m represents the sensitivity matrix under mode m; L m Represents the column vector (m columns) corresponding to the left characteristic matrix under mode m; T m represents the row vector (m rows) corresponding to the right characteristic matrix under mode m; n represents the matrix dimension.

[0016] Preferably, the modal sensitivity analysis includes:

[0017] The modal sensitivity of the component parameters in parallel at the system nodes is determined according to the following calculation formula:

[0018]

[0019] in, represents the modal sensitivity of the parallel conductive element at node i; Re(λ m ) represents the modal admittance λ m The real part of Im(λm ) represents the modal admittance λ m The imaginary part of S ii Denotes the sensitivity matrix S m The i-th row and i-th column element of Re(S ii ) indicates S ii The real part of Im(S ii ) indicates S ii The imaginary part of .

[0020] Preferably, it also includes:

[0021] The modal sensitivity of the component parameters connected in series between system nodes is determined according to the following calculation formula:

[0022]

[0023] in, represents the modal sensitivity of the resistance element connected in series between nodes i and j; represents the modal sensitivity of the reactive element connected in series between nodes i and j; S i-j Expressed as sensitivity matrix S m Element S ii +S jj -S ij -S ji The result of the operation; S jj Denotes the sensitivity matrix S m The j-th row and j-th column element of S ij Denotes the sensitivity matrix S m The i-th row and j-th column element of S ji Denotes the sensitivity matrix S m The j-th row and i-th column element of Re(S i-j ) indicates S i-j The real part of Im(S i-j ) indicates S i-j R represents the initial value of the resistance element connected in series between nodes i and j; X represents the initial value of the reactance element connected in series between nodes i and j.

[0024] Preferably, the modal frequency sensitivity includes:

[0025] The derivatives of conductance and susceptance with respect to R, L, C, and frequency f in the RLC series branch model are determined using the following formulas:

[0026]

[0027]

[0028]

[0029] Where, f represents the resonant frequency (ω=2πf); R, x L 、x C They represent the initial values ​​of resistance, inductance, and capacitance in the RLC branch formed by parallel components at the node, or the initial values ​​of resistance, inductance, and capacitance in the RLC branch formed by series components between nodes.

[0030] Preferably, it also includes:

[0031] The modal frequency sensitivity of the component parameters connected in parallel at the system node i at the resonant frequency f is determined according to the following calculation formula:

[0032]

[0033] Where, f is the resonant frequency (Hz); Δf is the step accuracy; α is the impedance admittance of the component; Re(S ii ) f+Δf Re(S) when the frequency is f+Δf ii ) value; Re(S ii ) f-Δf Re(S) when the frequency is f-Δf ii ) value; Im(S ii ) f+Δf Indicates Im(S) when the frequency is f+Δf ii ) value; Im(S ii ) f-Δf Indicates Im(S) when the frequency is f-Δf ii )value; When the frequency is f+2Δf|λ m |value; When the frequency is f-2Δf|λ m |value; When the frequency is f, |λ m |value; The resonant frequency f represents the frequency sensitivity of the resistive element in the parallel branch of node i; The resonant frequency f represents the frequency sensitivity of the reactive elements in the parallel branch of node i; The resonant frequency f represents the frequency sensitivity of the capacitive element in the parallel branch of node i.

[0034] Preferably, it also includes:

[0035] The modal frequency sensitivity of the component parameters connected in series between system nodes i and j at the resonant frequency f is determined according to the following calculation formula:

[0036]

[0037] Among them, Re(S i-j ) f+Δf Re(S) when the frequency is f+Δf i-j ) value; Re(S i-j ) f-Δf Re(S) when the frequency is f-Δf i-j ) value; Im(S i-j ) f+Δf Indicates Im(S) when the frequency is f+Δf i-j ) value; Im(S i-j ) f-Δf Indicates Im(S) when the frequency is f-Δf i-j )value; The resonant frequency f represents the frequency sensitivity of the resistance element in series between nodes i and j; The resonant frequency f represents the frequency sensitivity of the reactive element in series between nodes i and j; The resonant frequency f represents the frequency sensitivity of the capacitive element connected in series between nodes i and j.

[0038] Preferably, obtaining the classification result includes:

[0039] The proportion of modal sensitivity of each modal component in the corresponding attribute is determined according to the following calculation formula:

[0040]

[0041] in, Indicates the modal sensitivity ratio of the i-th inductive element when the resonant frequency corresponds to f in mode m; represents the modal sensitivity ratio of the i-th capacitive element under mode m; represents the modal sensitivity of the i-th inductive element under mode m; represents the modal sensitivity of the i-th capacitive element under mode m; It represents the sum of the absolute values ​​of the modal sensitivities of all inductive elements under mode m; It represents the sum of the absolute values ​​of the modal sensitivities of all capacitive components in mode m.

[0042] Preferably, it also includes:

[0043] The proportion of the modal frequency sensitivity of each modal component in the corresponding attribute is determined according to the following calculation formula:

[0044]

[0045] in, Indicates the modal frequency sensitivity ratio of the i-th inductive element when the resonant frequency corresponds to f in mode m; represents the modal frequency sensitivity ratio of the i-th capacitive element under mode m; represents the modal frequency sensitivity of the i-th inductive element under mode m; represents the modal frequency sensitivity of the i-th capacitive element under mode m; It represents the sum of the absolute values ​​of the modal frequency sensitivities of all inductive elements under mode m; It represents the sum of the absolute values ​​of the modal frequency sensitivities of all capacitive components in mode m.

[0046] Preferably, the determining whether the percentage of the modal sensitivity analysis result or the modal frequency sensitivity analysis result corresponding to a certain component in the respective category exceeds a set threshold comprises:

[0047] Use the following calculation formula to determine whether the capacitive and inductive components are the key components that cause resonance at the resonant frequency f:

[0048]

[0049] Here, T1 and T2 represent the threshold values ​​for determining the sensitivity of the element.

[0050] In summary, the implementation of the embodiments of the present invention has the following beneficial effects:

[0051] The present invention provides a method for identifying key components that cause wide-band resonance, and proposes a method for distinguishing key resonant components by comprehensively analyzing modal sensitivity and modal frequency sensitivity and calculating the sensitivity ratio according to component attributes. This eliminates the interference of differences in the sensitivity value ranges of components with different attributes on the distinction results of the main resonant components, and provides a basis for determining the key resonant components of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0053] Figure 1 1 is a schematic diagram of the main process of a method for identifying key components causing broadband resonance in an embodiment of the present invention.

[0054] Figure 2 The figure is a logic diagram of a method for identifying key components causing broadband resonance according to an embodiment of the present invention.

[0055] Figure 3Schematic diagram of an RLC series circuit in modal frequency sensitivity according to an embodiment of the present invention.

[0056] Figure 4 Schematic diagram of the modal sensitivity ratio of inductive components in an embodiment of the present invention.

[0057] Figure 5 Schematic diagram of the modal frequency sensitivity ratio of inductive components in an embodiment of the present invention.

[0058] Figure 6 Schematic diagram of the modal sensitivity ratio of capacitive components in an embodiment of the present invention.

[0059] Figure 7 Schematic diagram of the modal frequency sensitivity ratio of capacitive components in an embodiment of the present invention. DETAILED DESCRIPTION

[0060] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0061] like Figure 1 and Figure 2 FIG. 1 is a schematic diagram of an embodiment of a method for identifying key components causing broadband resonance provided by the present invention. In this embodiment, the method includes the following steps:

[0062] Step S1 : determining network modal information, wherein the network modal information includes at least a resonant frequency and a corresponding sensitivity matrix; that is, performing modal analysis on the power network to determine the resonant frequency and the corresponding sensitivity matrix.

[0063] In a specific embodiment, the resonant frequency of the system is determined according to the following calculation formula:

[0064]

[0065] Where f represents the resonant frequency in Hz; Y represents the admittance matrix of the system; Λ represents the eigenvalue matrix of matrix Y; T represents the eigenvector matrix of matrix Y, recorded as the right eigenmatrix; L represents the inverse matrix of the eigenvector matrix T, recorded as the left eigenmatrix; if Y is of order n, within the frequency range to be studied, a certain frequency step size is set, and the system admittance matrix at each frequency is diagonally decomposed, and the eigenvalues ​​in Λ are connected according to the frequency points of the step size to obtain n curves. The frequency corresponding to the peak of the curve is the resonant frequency f, λ m represents the modal admittance, which is the smallest of all eigenvalues ​​of Λ at the resonant frequency f; m represents the mode number.

[0066] And, the sensitivity matrix corresponding to the resonant frequency is determined according to the following calculation formula:

[0067]

[0068] Where m represents the mode number; S m represents the sensitivity matrix under mode m; L m Represents the column vector (m columns) corresponding to the left characteristic matrix under mode m; T m represents the row vector (m rows) corresponding to the right characteristic matrix under mode m; n represents the matrix dimension.

[0069] Step S2: performing modal sensitivity analysis and modal frequency sensitivity analysis according to the network modal information, and classifying the modal sensitivity analysis results and the modal frequency sensitivity analysis results according to capacitive parameters or inductive parameters, and determining the percentages within their respective categories to obtain classification results, wherein the modal sensitivity analysis includes the first-order derivative of modal admittance with respect to component parameters; Figure 3 In the RLC series circuit shown, the modal frequency sensitivity includes the derivatives of the conductance and susceptance with respect to R, L, C and frequency f in the RLC series branch model, and the first-order derivative of the resonant frequency with respect to the component parameters; that is, modal sensitivity analysis and modal frequency sensitivity analysis are performed based on the sensitivity matrix of the modal analysis, wherein the modal sensitivity analysis includes the first-order derivative of the modal admittance with respect to the component parameters, and the modal frequency sensitivity includes the first-order derivative of the resonant frequency with respect to the component parameters.

[0070] In a specific embodiment, the modal sensitivity analysis includes:

[0071] The modal sensitivity of the component parameters in parallel at the system nodes is determined according to the following calculation formula:

[0072]

[0073] in, represents the modal sensitivity of the parallel conductive element at node i; Re(λ m ) represents the modal admittance λ m The real part of Im(λ m ) represents the modal admittance λ m The imaginary part of S ii Denotes the sensitivity matrix S m The i-th row and i-th column element of Re(S ii ) indicates S ii The real part of Im(S ii ) indicates S ii The imaginary part of .

[0074] Specifically, the modal sensitivity of the component parameters connected in series between system nodes is determined according to the following calculation formula:

[0075]

[0076] in, represents the modal sensitivity of the resistance element connected in series between nodes i and j; represents the modal sensitivity of the reactive element connected in series between nodes i and j; S i-j Expressed as sensitivity matrix S m Element S ii +S jj -S ij -S ji The result of the operation; S jj Denotes the sensitivity matrix S m The j-th row and j-th column element of S ij Denotes the sensitivity matrix S m The i-th row and j-th column element of S ji Denotes the sensitivity matrix S m The j-th row and i-th column element of Re(S i-j ) indicates S i-j The real part of Im(S i-j ) indicates S i-j R represents the initial value of the resistance element connected in series between nodes i and j; X represents the initial value of the reactance element connected in series between nodes i and j.

[0077] In this embodiment, the derivative calculation formulas of conductance and susceptance with respect to R, L, C, and frequency f in the RLC series branch model are determined according to the following calculation formulas:

[0078]

[0079]

[0080]

[0081] Where f represents the resonant frequency; R, x L 、x C They respectively represent the initial values ​​of the resistance, inductive reactance, and capacitive reactance in the RLC branch composed of parallel elements at the node, or the initial values ​​of the resistance, inductive reactance, and capacitive reactance of the RLC branch composed of series elements between nodes (depending on whether the element in question is connected in parallel at node i or between node i and other nodes j).

[0082] Specifically, the modal frequency sensitivity of the component parameters connected in parallel at the system node i at the resonant frequency f is determined according to the following calculation formula:

[0083]

[0084] Where, f is the resonant frequency (Hz); Δf is the step accuracy; α is the impedance admittance of the component; Re(S ii ) f+Δf Re(S) when the frequency is f+Δf ii ) value; Re(S ii ) f-Δf Re(S) when the frequency is f-Δf ii ) value; Im(S ii ) f+Δf Indicates Im(S) when the frequency is f+Δf ii ) value; Im(S ii ) f-Δf Indicates Im(S) when the frequency is f-Δf ii )value; When the frequency is f+2Δf|λ m |value; When the frequency is f-2Δf|λ m |value; When the frequency is f, |λ m |value; The resonant frequency f represents the frequency sensitivity of the resistive element in the parallel branch of node i; The resonant frequency f represents the frequency sensitivity of the reactive elements in the parallel branch of node i; The resonant frequency f represents the frequency sensitivity of the capacitive element in the parallel branch of node i.

[0085] The modal frequency sensitivity of the component parameters connected in series between system nodes i and j at the resonant frequency f is determined according to the following calculation formula:

[0086]

[0087] Among them, Re(S i-j ) f+Δf Re(S) when the frequency is f+Δf i-j ) value; Re(S i-j ) f-Δf Re(S) when the frequency is f-Δf i-j ) value; Im(S i-j ) f+Δf Indicates Im(S) when the frequency is f+Δf i-j ) value; Im(S i-j ) f-Δf Indicates Im(S) when the frequency is f-Δf i-j )value; The resonant frequency f represents the frequency sensitivity of the resistance element in series between nodes i and j; The resonant frequency f represents the frequency sensitivity of the reactive element in series between nodes i and j; The resonant frequency f represents the frequency sensitivity of the capacitive element connected in series between nodes i and j.

[0088] According to the above process, the two analysis results are classified into capacitive and inductive types respectively. Finally, the respective proportions of modal sensitivity and modal frequency sensitivity are determined, that is, they are calculated as percentages within their respective categories: Since the natural resonant frequency is caused by the combination of inductive and capacitive elements, only the sensitivity proportions of inductive and capacitive elements are considered.

[0089] The proportion of modal sensitivity of each modal component in the corresponding attribute is determined according to the following calculation formula:

[0090]

[0091] in, Indicates the modal sensitivity ratio of the i-th inductive element when the resonant frequency corresponds to f in mode m; represents the modal sensitivity ratio of the i-th capacitive element under mode m; represents the modal sensitivity of the i-th inductive element under mode m; represents the modal sensitivity of the i-th capacitive element under mode m; It represents the sum of the absolute values ​​of the modal sensitivities of all inductive elements under mode m; It represents the sum of the absolute values ​​of the modal sensitivities of all capacitive components in mode m.

[0092] And, the proportion of the modal frequency sensitivity of each modal component in the corresponding attribute is determined according to the following calculation formula:

[0093]

[0094] in, Indicates the modal frequency sensitivity ratio of the i-th inductive element when the resonant frequency corresponds to f in mode m; represents the modal frequency sensitivity ratio of the i-th capacitive element under mode m; represents the modal frequency sensitivity of the i-th inductive element under mode m; represents the modal frequency sensitivity of the i-th capacitive element under mode m; It represents the sum of the absolute values ​​of the modal frequency sensitivities of all inductive elements under mode m; It represents the sum of the absolute values ​​of the modal frequency sensitivities of all capacitive components in mode m.

[0095] Step S3: Based on the classification results, determine whether the percentage of the modal sensitivity analysis results or modal frequency sensitivity analysis results corresponding to a component within their respective categories exceeds a set threshold. If not, the component is determined not to be a key component that causes resonance at that frequency; if exceeded, the component is determined to be a key component that causes resonance at that frequency. In other words, determine whether the capacitive and inductive components are key components that cause resonance at resonant frequency f. Based on network testing, the threshold for determining component sensitivity can be set to 10% for systems with a small number of nodes. When the system has a large number of nodes, the threshold can be adjusted downward based on the number of key components required.

[0096] In a specific embodiment, whether the capacitive element and the inductive element are key elements that induce resonance at the resonant frequency f is determined according to the following calculation formula:

[0097]

[0098] Here, T1 and T2 represent the threshold values ​​for determining the sensitivity of the element.

[0099] In a specific embodiment, Figure 4 is the modal sensitivity ratio of the inductive components in the system. It can be seen that X4 has the largest ratio and may play a major role in resonance. Figure 5 is the modal frequency sensitivity ratio of the inductive components in the system. It can be seen that X3, X4 and X5 may play a major role in resonance; Figure 6 The modal sensitivity ratio of the capacitive components in the system shows that B4, B5, and B6 may play a major role in the resonance at this frequency. Figure 7 The modal frequency sensitivity ratio of the capacitive components in the system shows that B1, B2, B3, and B7 may play a major role in the resonance at this frequency.

[0100] If the modal sensitivity ratio of a component parameter exceeds the threshold or the modal frequency sensitivity ratio exceeds the threshold, the component can be determined to be a key component that causes resonance; if the modal sensitivity ratio and modal frequency sensitivity ratio of a component parameter do not exceed the threshold, the component can be considered not to be a key component that causes resonance. According to the judgment basis, if one of the modal sensitivity ratio and modal frequency sensitivity ratio of a component exceeds the threshold, it can be considered to be a key component that causes resonance. The threshold can be set at 10%, and it can be lowered or raised as the number of system nodes increases or decreases and the number of key resonance components that need to be determined is increased or decreased. If the judgment is based on the 10% threshold, the main capacitive components that cause resonance are X3, X4 and X5, and the ratios of all capacitive components are not much different. According to the judgment basis, all capacitive components participate in the resonance at this frequency.

[0101] In summary, the implementation of the embodiments of the present invention has the following beneficial effects:

[0102] The present invention provides a method for identifying key components that cause wide-band resonance, and proposes a method for distinguishing key resonant components by comprehensively analyzing modal sensitivity and modal frequency sensitivity and calculating the sensitivity ratio according to component attributes. This eliminates the interference of differences in the sensitivity value ranges of components with different attributes on the distinction results of the main resonant components, and provides a basis for determining the key resonant components of the power system.

[0103] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for identifying key components that cause broadband resonance, characterized in that: include: Determining network modal information, wherein the network modal information includes at least a resonant frequency and a sensitivity matrix corresponding thereto; Performing modal sensitivity analysis and modal frequency sensitivity analysis based on the network modal information, and classifying the modal sensitivity analysis results and the modal frequency sensitivity analysis results according to capacitive parameters or inductive parameters, respectively, and determining the percentages within their respective categories to obtain classification results, wherein the modal sensitivity analysis includes the first-order derivative of modal admittance with respect to component parameters; the modal frequency sensitivity includes the derivatives of conductance and susceptance with respect to R, L, C, and frequency f in the RLC series branch model, and the first-order derivative of the resonant frequency with respect to component parameters; Determine, based on the classification result, whether the percentage of the modal sensitivity analysis result or the modal frequency sensitivity analysis result corresponding to a certain component in the respective category exceeds a set threshold; if not, determine that the component is not a key component that causes resonance at the frequency; if exceeded, determine that the component is a key component that causes resonance at the frequency; Wherein, the modal sensitivity analysis includes: The modal sensitivity of the component parameters in parallel at the system nodes is determined according to the following calculation formula: in, represents the modal sensitivity of the parallel conductive element at node i; Re(λ m ) represents the modal admittance λ m The real part of Im(λ m ) represents the modal admittance λ m The imaginary part of S ii Denotes the sensitivity matrix S m The i-th row and i-th column element of Re(S ii ) indicates S ii The real part of Im(S ii ) indicates S ii The imaginary part of And, the modal sensitivity of the component parameters connected in series between the system nodes is determined according to the following calculation formula: in, represents the modal sensitivity of the resistance element connected in series between nodes i and j; represents the modal sensitivity of the reactive element connected in series between nodes i and j; S i-j Expressed as sensitivity matrix S m Element S ii +S jj -S ij -S ji The result of the operation; S jj Denotes the sensitivity matrix S m The j-th row and j-th column element of S ij Denotes the sensitivity matrix S m The i-th row and j-th column element of S ji Denotes the sensitivity matrix S m The j-th row and i-th column element of Re(S i-j ) indicates S i-j The real part of Im(S i-j ) indicates S i-j R represents the initial value of the resistance element connected in series between node i and node j; X represents the initial value of the reactance element connected in series between node i and node j.

2. The method according to claim 1, wherein Determining the network modality information includes: Determine the resonant frequency of the system using the following calculation formula: Where f represents the resonant frequency; Y represents the admittance matrix of the system; Λ represents the eigenvalue matrix of matrix Y; T represents the eigenvector matrix of matrix Y, recorded as the right eigenmatrix; L represents the inverse matrix of the eigenvector matrix T, recorded as the left eigenmatrix; if Y is of order n, the system admittance matrix at each frequency is diagonally decomposed, and the eigenvalues ​​in Λ are connected at the frequency points of the step size to obtain n curves. The frequency corresponding to the peak of the curve is the resonant frequency f, λ m represents the modal admittance, which is the smallest of all eigenvalues ​​of Λ at the resonant frequency f; m represents the mode number; And, the sensitivity matrix corresponding to the resonant frequency is determined according to the following calculation formula: Where m represents the mode number; S m represents the sensitivity matrix under mode m; L m represents the column vector corresponding to the left characteristic matrix under mode m; T m represents the row vector corresponding to the right eigenvalue matrix under mode m; n represents the matrix dimension.

3. The method according to claim 2, wherein The modal frequency sensitivity includes: The derivatives of conductance and susceptance with respect to R, L, C, and frequency f in the RLC series branch model are determined using the following formulas: Where f represents the resonant frequency; R, x L They represent the initial values ​​of resistance, inductive reactance, and capacitive reactance in the RLC branch formed by the parallel components at the node; x C Indicates the initial values ​​of the resistance, inductive reactance, and capacitive reactance of the RLC branch formed by the series components between the nodes.

4. The method according to claim 3, wherein Also includes: The modal frequency sensitivity of the component parameters connected in parallel at the system node i at the resonant frequency f is determined according to the following calculation formula: Where f is the resonant frequency; Δf is the step accuracy; α is the impedance admittance of the component; Re(S ii ) f+Δf Re(S) when the frequency is f+Δf ii ) value; Re(S ii ) f-Δf Re(S) when the frequency is f-Δf ii ) value; Im(S ii ) f+Δf Indicates Im(S) when the frequency is f+Δf ii ) value; Im(S ii ) f-Δf Indicates Im(S) when the frequency is f-Δf ii )value; When the frequency is f+2Δf|λ m |value; When the frequency is f-2Δf|λ m |value; When the frequency is f, |λ m |value; The resonant frequency f represents the frequency sensitivity of the resistive element in the parallel branch of node i; The resonant frequency f represents the frequency sensitivity of the reactive elements in the parallel branch of node i; The resonant frequency f represents the frequency sensitivity of the capacitive element in the parallel branch of node i.

5. The method according to claim 4, wherein Also includes: The modal frequency sensitivity of the component parameters connected in series between system nodes i and j at the resonant frequency f is determined according to the following calculation formula: Among them, Re(S i-j ) f+Δf Re(S) when the frequency is f+Δf i-j ) value; Re(S i-j ) f-Δf Re(S) when the frequency is f-Δf i-j ) value; Im(S i-j ) f+Δf Indicates Im(S) when the frequency is f+Δf i-j ) value; Im(S i-j ) f-Δf Indicates Im(S) when the frequency is f-Δf i-j )value; The resonant frequency f represents the frequency sensitivity of the resistance element in series between nodes i and j; The resonant frequency f represents the frequency sensitivity of the reactive element in series between nodes i and j; The resonant frequency f represents the frequency sensitivity of the capacitive element connected in series between nodes i and j.

6. The method according to claim 1 or 5, wherein: The classification results obtained include: The proportion of modal sensitivity of each modal component in the corresponding attribute is determined according to the following calculation formula: in, Indicates the modal sensitivity ratio of the i-th inductive element when the resonant frequency corresponds to f in mode m; represents the modal sensitivity ratio of the i-th capacitive element under mode m; represents the modal sensitivity of the i-th inductive element under mode m; represents the modal sensitivity of the i-th capacitive element under mode m; It represents the sum of the absolute values ​​of the modal sensitivities of all inductive elements under mode m; It represents the sum of the absolute values ​​of the modal sensitivities of all capacitive components in mode m.

7. The method according to claim 6, wherein Also includes: The proportion of the modal frequency sensitivity of each modal component in the corresponding attribute is determined according to the following calculation formula: in, Indicates the modal frequency sensitivity ratio of the i-th inductive element when the resonant frequency corresponds to f in mode m; represents the modal frequency sensitivity ratio of the i-th capacitive element under mode m; represents the modal frequency sensitivity of the i-th inductive element under mode m; represents the modal frequency sensitivity of the i-th capacitive element under mode m; It represents the sum of the absolute values ​​of the modal frequency sensitivities of all inductive elements under mode m; It represents the sum of the absolute values ​​of the modal frequency sensitivities of all capacitive components in mode m.

8. The method according to claim 7, wherein The determining whether the percentage of the modal sensitivity analysis result or the modal frequency sensitivity analysis result corresponding to a component in the respective category exceeds a set threshold includes: Use the following calculation formula to determine whether the capacitive and inductive components are the key components that cause resonance at the resonant frequency f: Here, T1 and T2 represent the threshold values ​​for determining the sensitivity of the element.

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