Epoxy mica insulation state evaluation method for high-voltage generator stator

Abstract

The invention relates to the technical field of stator bar insulation aging state evaluation, and discloses a high-voltage generator stator epoxy mica insulation state evaluation method, which comprises the following steps: firstly, manufacturing a bar model through an F-level large generator stator bar, and adopting epoxy-mica composite insulation as main insulation for an insulation layer on the bar model; 180 DEG C is adopted as the thermal aging temperature, and performance detection is conducted on the bar model in four times of 0 h, 240 h, 530 h and 860 h; carrying out PDC testing on the coil bar models with different thermal aging degrees through a PDC testing platform; a direct-current power supply applies direct-current high voltage to the tested bar model, an insulating medium enters a polarization stage, and polarization current ipol and depolarization current idepo are measured respectively; constructing a modified fractional order dielectric model based on a KWW theory; sGMD is adopted to adaptively identify the number of polarization branches; and dielectric parameters related to the aging state are extracted based on a multi-modal immune algorithm of sorting, and the stator insulation state is evaluated. According to the invention, the stator insulation state can be accurately evaluated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stator bar insulation aging state evaluation, in particular to a high-voltage generator stator epoxy mica insulation state evaluation method. BACKGROUND

[0002] As one of the most critical equipment in the ship power system, the reliability of the ship generator directly affects the safety of the ship. The main insulation of the generator stator usually adopts epoxy-mica composite insulation, and insulation state evaluation is an important work to judge the condition of the generator. The traditional insulation resistance, power frequency dielectric loss and DC withstand voltage test are limited to single parameter analysis mode, which is difficult to realize quantitative diagnosis of insulation defects, especially cannot effectively reflect the differential influence of load fluctuation on insulation aging in operation, resulting in lack of objective basis for judging the aging "light" and "heavy". The dielectric response technology has been widely concerned in the field of on-site insulation diagnosis due to its advantages of non-destructive online measurement, convenient operation and carrying rich insulation information.

[0003] Therefore, in view of the above problems, a high-voltage generator stator epoxy mica insulation state evaluation method is needed. SUMMARY

[0004] The purpose of the present application is to provide a high-voltage generator stator epoxy mica insulation state evaluation method. The present application introduces KWW theory to construct a modified fractional order dielectric model under the framework of fractional calculus; adopts SGMD to adaptively identify the number of polarization branches, and uses a sorting-based multi-modal immune algorithm to extract dielectric parameters related to the aging state, so as to accurately evaluate the insulation state of the stator.

[0005] The present application is implemented as follows:

[0006] The present application provides a high-voltage generator stator epoxy mica insulation state evaluation method, which is specifically executed according to the following steps:

[0007] S1: A bar model is made through a F-class large generator stator bar, the insulation layer on the bar model adopts epoxy-mica composite insulation as the main insulation, the insulation layer has a thickness of 4mm, the bar model is 1.6m long, the semiconductor layer at both ends of the bar model is stripped, the aluminum conductor with a length of 4-6cm is exposed as a high-voltage measurement electrode, and an aluminum foil with a length of 50-70cm is pasted on the surface of the low-resistance varnish of the bar model, and the aluminum foil is tightly fastened with glass cloth;

[0008] S2: Accelerated thermal aging experiment is performed on the bar model, 180℃ is used as the thermal aging temperature, and performance detection is performed on the bar model at 0h, 240h, 530h and 860h respectively;

[0009] S3: Through the PDC test platform, the PDC test is performed on the linear rod model with different thermal aging degrees; the direct current power supply applies direct current high voltage to the measured linear rod model, the polarization voltage is set to 1kV, the PDC measurement is performed on the stator sample, the polarization / de-polarization time is 1500s, the insulating medium enters the polarization stage, and the polarization current ipol and the de-polarization current idepo are measured respectively;

[0010] S4: Constructing a modified fractional dielectric model based on the KWW theory; the following steps are specifically performed:

[0011] S4.1: The Caputo type fractional derivative is used, as follows:

[0012]

[0013] The Caputo fractional derivative in the above formula is mathematically transformed to obtain a fractional integral operator, as follows:

[0014]

[0015] S4.2: The continuous power-law polarization characteristics of the material in a wide frequency range are characterized by a capacity resistor; as follows:

[0016]

[0017] Wherein, R and C represent resistance and capacitance respectively; D1 tQ(t) and D0 tQ(t) are the 1st and 0th order fractional derivatives of Q(t) with respect to time t, and α i Fractional integral operator And the fractional dielectric performance equation can be obtained as follows:

[0018]

[0019]

[0020] The integral form of the above formula is obtained to obtain an explicit solution, and the result of the fractional integral to the step is as follows:

[0021]

[0022] And the charge expression of the ith branch is obtained by substituting the above formula into the previous formula:

[0023]

[0024] The derivative of t is obtained to obtain the single-branch polarization current, as follows:

[0025]

[0026] Based on the stretching exponent ki of KWW theory, the modified relaxation current is established as follows:

[0027]

[0028] In the above formula, the parameter k i The distribution width of the relaxation time in physics can accurately capture the deviation characteristics of the real relaxation process of the stator main insulation from the ideal model;

[0029] S4.4: The ideal polarization current obtained is combined with the KWW theory, and the total polarization current Ipol(t) of the epoxy mica insulation is as follows:

[0030]

[0031] In the formula, I G represents the conductive current; C i represents the fractional capacitance of the i-th polarization branch, and α i characterizes the fractional order (0-1) and determines the shape of the power-law core ; τ i is the relaxation time constant of the i-th polarization branch; k i is a distribution parameter describing the distribution width of the branch relaxation time and the decay speed of the current tail, and each polarization branch is composed of 4 model parameters (C i , τ i , α i , k i ). By changing these parameters, the polarization current of different branches is simulated, thereby characterizing the complex relaxation process in the stator insulation;

[0032] Based on the calculation of the eigenvalues of the Hamilton matrix by phase space reconstruction, the symplectic geometric modal component is constructed by the corresponding eigenvectors, and the original polarization current signal is set as x, where n is the length of the signal. The trajectory matrix X is obtained by phase space reconstruction on the original signal x, as follows:

[0033]

[0034] In the formula, m=n-(d-1)λ; λ is the delay time; d is the embedding dimension, and the corresponding trajectory matrix X is obtained by selecting the embedding dimension d and the time delay λ. The Hamilton matrix M is obtained according to the trajectory matrix X as follows: ;

[0035] In the formula, A=X T X, M is squared to obtain N=M 2 , and the symplectic orthogonal matrix Q is constructed by householder transformation, as follows:

[0036]

[0037] From the properties of Hamilton matrix, A eigenvalue σ i is:

[0038] ;

[0039] By arranging the eigenvalues σi in descending order σ1>σ2>…>σd, calculating the eigenvectors Qi corresponding to these eigenvalues, and combining the trajectory matrix X to obtain the construction matrix Z; as follows:

[0040]

[0041] By diagonal averaging, the reconstruction matrix Z i is converted into a set of time series with length n; the elements in Z i are defined as Z i,j ; according to the above formula, after diagonal averaging, Z i is converted into a set of time series Y i with length n=[y1,y2,…,y n ];

[0042]

[0043] In the formula, when m ; when m≥d, .

[0044] S5: adopt SGMD adaptive recognition polarization branch number;

[0045] The polarization current is reconstructed by using samples S1, S2, S3 and S4, and compared with the measured polarization current, such as Figure 5 , the polarization branch number of the measured polarization current is determined;

[0046] The polarization branch numbers corresponding to samples S1, S2, S3 and S4 are 2, 3, 5 and 6 respectively; after determining the polarization branch number, the parameters of MFD model are solved by RMIA algorithm, and the model parameters of different aging samples.

[0047] The fitting technology is used to expand it, and a dielectric characteristic parameter database covering different aging degrees is constructed; as follows:

[0048]

[0049]

[0050]

[0052] S6: extracting and evaluating the dielectric parameters related to the aging state based on the sorting-based multi-modal immune algorithm.

[0053] T1, T2, T3 and T4 correspond to the thermal aging time of each characteristic quantity respectively.

[0054]

[0055] The measured characteristic quantities are respectively substituted into the above formula to obtain four equivalent aging times respectively.

[0056]

[0057] Wherein, T is the calculated thermal aging time.

[0058] Further, the application provides a computer device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to realize the steps of the high-voltage generator stator epoxy mica insulation state evaluation method according to any one of the above.

[0059] Further, the application provides a computer storage medium, which can store a computer program in the medium, wherein the program is executed to sequentially execute the steps of the high-voltage generator stator epoxy mica insulation state evaluation method according to any one of the above.

[0060] Compared with the prior art, the application has the following beneficial effects:

[0061] 1. The application introduces KWW theory in the framework of fractional calculus in the modified fractional order dielectric model, and explains the non-Debye deviation behavior in the dielectric relaxation process.

[0062] 2. The application can adaptively identify the number of polarization branches of the MFD model by using the symplectic geometric modal decomposition method, and overcome the dependence on prior knowledge of the traditional method.

[0063] 3. The application establishes a dielectric characteristic parameter database covering different aging degrees by fitting technology, and deduces the quantitative relationship between the characteristic parameters and the equivalent thermal aging time, so as to accurately evaluate the stator insulation state. BRIEF DESCRIPTION OF DRAWINGS

[0064] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope, and other related drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0065] Figure 1 is a method flowchart of the present application;

[0066] Figure 2 is a PDC measurement platform diagram of the present application;

[0067] Figure 3 is a graph correction fractional dielectric model diagram of the present application;

[0068] Figure 4 is a dielectric property diagram of a capacitive resistor of the present application;

[0069] Figure 5 is a parameter solving schematic diagram of a ranking-based multi-modal immune algorithm (RMIA) of the present application;

[0070] Figure 6 is a graph of the determination of the number of polarization branches of different thermal aging samples (a) sample S1 energy entropy curve (b) sample S2 energy entropy curve (c) sample S3 energy entropy curve (d) sample S4 energy entropy curve of the present application;

[0071] Figure 7 is a comparison diagram of the calculated results of the polarization current and the traditional ED model and the measured data of the present application;

[0072] Figure 8 is a characteristic parameter fitting diagram of different thermal aging degrees (a) maximum fractional capacitance Cmax (b) maximum time constant τmax (c) conductance current IG (d) polarization branch number N of the present application;

[0073] Figure 9 is a different service year limited sub-wire rod and polarization current diagram of a specific embodiment of the present application. DETAILED DESCRIPTION

[0074] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only for selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0075] Referring to Figures 1-9 , the present application provides a high-voltage generator stator epoxy mica insulation state evaluation method, which is specifically executed according to the following steps:

[0076] S1: A line bar model is made through a F-grade large generator stator line bar, the insulation layer on the line bar model adopts a main insulation of epoxy-mica composite insulation, the insulation layer thickness is 4 mm, the line bar model is 1.6 m long, the semiconductor layer of 8 cm at both ends of the line bar model is stripped, the aluminum conductor with an exposed length of 4-6 cm is exposed as a high-voltage measurement electrode, and an aluminum foil with a length of 50-70 cm is pasted on the low-resistance varnish surface of the line bar model, and the aluminum foil is tightly fastened with glass cloth;

[0077] As Figure 2 , S2: An accelerated thermal aging experiment is performed on the line bar model, 180 DEG C is adopted as the thermal aging temperature, and performance detection is performed on the line bar model at four times of 0 h, 240 h, 530 h and 860 h;

[0078] S3: PDC testing is performed on the line bar model with different thermal aging degrees through a PDC testing platform; a direct-current power supply applies a direct-current high voltage to the measured line bar model, a polarization voltage of 1 kV is set, PDC measurement is performed on the stator sample, the polarization / de-polarization time is 1500 s, the insulation medium enters a polarization stage, and the polarization current ipol and the de-polarization current idepo are measured respectively;

[0079] As Figures 3-4 , S4: A modified fractional-order dielectric model is constructed based on the KWW theory; the following steps are specifically executed:

[0080] S4.1: A Caputo type fractional derivative is adopted, as follows:

[0081]

[0082] Mathematical transformation of Caputo fractional derivative in the above formula, get fractional integral operator, as follows:

[0083]

[0084] S4.2: through the container resistance vessel characterization material in the wide frequency range of continuous power law polarization characteristics; as follows:

[0085]

[0086] Where R and C represent resistance and capacitance, respectively; D1 tQ(t) and D0 tQ(t) are the 1st and 0th order fractional derivative of Q(t) with respect to time t, respectively, on both sides of the above formula, α i Fractional integral operator And the fractional dielectric performance equation can be obtained by the following formula:

[0087]

[0088]

[0089] The integral form of the above formula is obtained by the explicit solution, and the fractional integral of the step is as follows:

[0090]

[0091] And this result is substituted into the previous formula, and the charge expression of the i branch is:

[0092]

[0093] The derivative of t is obtained, and the single branch polarization current is as follows:

[0094]

[0095] Based on the stretching index ki of KWW theory, the modified relaxation current is established, as follows:

[0096]

[0097] In the above formula, the parameter k i Physically represents the distribution width of the relaxation time, which can accurately capture the deviation characteristics of the ideal model of the real relaxation process of the stator main insulation;

[0098] S4.4: the ideal polarization current obtained is combined with KWW theory, and the total polarization current Ipol(t) of epoxy mica insulation is as follows:

[0099]

[0100] In the formula, I G Indicates electrical conduction current; C i Let α represent the fractional capacitance of the i-th polarization branch. i The fractional order (0–1) determines the power law kernel. The shape; τ i The relaxation time constant of the i-th polarization branch; k i These are distributed parameters describing the width of the branch relaxation time distribution and the rate of current tail decay. Each polarization branch has four model parameters (C). i τ i α i k i The system consists of components, and by varying these parameters, the polarization currents of different branches are simulated, thereby characterizing the complex relaxation process in the stator insulation.

[0101] Based on phase space reconstruction, the eigenvalues ​​of the Hamiltonian matrix are calculated, and symplectic geometric mode components are constructed through the corresponding eigenvectors. The original polarization current signal is assumed to be... Where n is the signal length, the trajectory matrix X is obtained by reconstructing the phase space of the original signal x, as shown in the following equation:

[0102]

[0103] In the formula, m = n - (d - 1)λ; λ is the delay time; d is the embedding dimension. By selecting the embedding dimension d and the time delay λ, the corresponding trajectory matrix X is obtained. The Hamiltonian matrix M is then obtained from the trajectory matrix X. ;

[0104] In the formula, A=X T X, squaring M, gives N=M 2 The symplectic orthogonal matrix Q is constructed through the householder transformation, as shown in the following formula:

[0105]

[0106] From the properties of the Hamiltonian matrix, we know that the eigenvalues ​​σ of A are... i for:

[0107] ;

[0108] By arranging the eigenvalues ​​σi in descending order (σ1 > σ2 > ... > σd), the corresponding eigenvectors Qi are calculated, and the constructed matrix Z is obtained by combining these eigenvalues ​​with the trajectory matrix X; as shown in the following equation:

[0109]

[0110] The reconstructed matrix Z is obtained by diagonal averaging. itransformed into a set of time series with length n; define Z i in the element as Z i,j ; diagonal average after the formula, so that Z i transformed into a set of time series with length n Y i =[y1,y2,…,y n ];

[0111]

[0112] In the formula, when m ; when m≥d, .

[0113] S5: SGMD adaptive identification of polarization branch number;

[0114] Using samples S1, S2, S3 and S4 to reconstruct the polarization current, and compared with the measured polarization current, such as Figure 5 , the polarization branch number of the measured polarization current is determined;

[0115] The polarization branch numbers corresponding to samples S1, S2, S3 and S4 are 2, 3, 5 and 6 respectively; After determining the polarization branch number, the parameters of the MFD model are solved by the RMIA algorithm; The model parameters of different aging samples are shown in Table I.

[0116] Table I Model parameters of different aging samples

[0117]

[0118] Using fitting technology to expand it, build a dielectric characteristic parameter database covering different aging degrees; As follows:

[0119]

[0120]

[0121]

[0123] As Figures 5-8 , S6: Based on the ranking of multi-modal immune algorithm to extract and aging state related dielectric parameters, evaluate the stator insulation state.

[0124] T1, T2, T3 and T4 correspond to the thermal aging time of each characteristic quantity. The inverse function of each fitting equation is obtained as follows: Table II, characteristic parameters under different aging degrees.

[0125]

[0126] Table II Characteristic parameters of different aging degrees

[0127]

[0128] The measured characteristic quantities are substituted into the above formula respectively to obtain four equivalent aging times. In order to reduce the uncertainty of a single index, an equal-weight average is used to obtain a comprehensive equivalent aging time, as follows:

[0129]

[0130] wherein T is the calculated thermal aging time.

[0131] In this embodiment, the process of the present application is calculated by specific example data, as follows:

[0132] To verify the accuracy and effectiveness of the MFD model designed in the present application for evaluating the aging state of the stator of the ship generator, the polarization current of the stator bar of 5 years, 9 years and 23 years of service life was measured, corresponding to samples D1, D2 and D3, respectively, as shown in Figure 9 Different service life stator bars and polarization currents.

[0133] The MFD model is highly consistent with the measured polarization current curve. Based on the model, the measured data is analyzed, and the characteristic parameters related to the degree of insulation aging are extracted, as shown in Table III.

[0134] Table III Characteristic parameters of different service life stator bars

[0135]

[0136] According to the characteristic parameters extracted from Table III, the thermal aging equivalent time of the stator insulation is calculated. According to the Arrhenius 10℃ degradation rule, and referring to the international standard IEC 60034, the thermal aging time of the stator bar is equivalent to the equivalent service life under the 105℃ reference, as shown in Table IV.

[0137] Table IV Equivalent 180° thermal aging time of different service life stator bars and calculated service life

[0138]

[0139] As shown in Table V, among the three groups of samples, the relative error of the calculated running life and the actual running life of D1, D2 and D3 is within 3%. The results show that the MFD model and the dielectric characteristic parameter database proposed in this paper can accurately calculate the stator insulation state.

[0140] The above merely describes the preferred embodiments of the present application and is not used to limit the present application. Various modifications and changes can be made by those skilled in the art to the present application without departing from the spirit and principle of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for evaluating the insulation condition of an epoxy mica of a high-voltage generator stator, characterized by: The following steps are specifically performed: S1: A bar model is made by F-class large generator stator bar, and the insulation layer on the bar model adopts main insulation of epoxy-mica composite insulation with a thickness of 4 mm. The bar model is 1.6 m long, and the semiconductor layer of 8 cm at both ends of the bar model is stripped to expose the aluminum conductor with a length of 4-6 cm as a high-voltage measurement electrode. An aluminum foil with a length of 50-70 cm is pasted on the low-resistance varnish surface of the bar model, and the aluminum foil is tightly fastened with glass cloth; S2: The bar model is subjected to accelerated thermal aging test, and 180 DEG C is used as the thermal aging temperature. The performance of the bar model is detected at 0 h, 240 h, 530 h and 860 h respectively; S3: The PDC test platform is used to test the PDC of the bar model with different thermal aging degrees. A direct current power supply is used to apply direct current high voltage to the measured bar model, and the polarization voltage is set to 1 kV. The polarization / de-polarization time of the stator sample is 1500 s. The insulation medium enters the polarization stage, and the polarization current ipol and the de-polarization current idepo are measured respectively; S4: A modified fractional-order dielectric model is constructed based on the KWW theory; S5: The SGMD adaptive identification polarization branch number is used; S6: The dielectric parameters related to the aging state are extracted based on the sorting multi-modal immune algorithm, and the stator insulation state is evaluated.

2. The method for evaluating the insulation condition of the stator of a high-voltage generator according to claim 1, characterized in that: In step S4, the following steps are specifically performed: S4.1: The Caputo type fractional derivative is used, as follows: The Caputo fractional derivative in the above formula is mathematically transformed to obtain a fractional integral operator, as follows: S4.2: The continuous power-law polarization characteristics of the material in a wide frequency range are characterized by a capacitance resistor; as follows: where R and C represent resistance and capacitance, respectively; D1 tQ(t) and D0 tQ(t) are the first and zero order fractional derivative of Q(t) with respect to time t, respectively, and α i order fractional integration operator and the fractional element dielectric property equation is given by The integral form of the above formula is obtained to obtain an explicit solution. Through step excitation U(t)= U0H(t), the result of the fractional integral on the step is as follows: And this result is substituted into the previous formula to obtain the charge expression of the i-th branch: Derivation of t can obtain the single-branch polarization current, as follows: 。 3. The method for evaluating the insulation condition of the stator of a high-voltage generator according to claim 2, characterized in that: Based on the stretching index ki of the KWW theory, the modified relaxation current is established, as follows: In the above formula, the parameter k i The distribution width of the relaxation time physically represents the deviation of the real relaxation process of the stator main insulation from the ideal model, and can accurately capture the deviation characteristics. S4.4: The obtained ideal polarization current is combined with the KWW theory, and the total polarization current Ipol(t) of the epoxy-mica insulation is as follows: In the formula, I G Indicates electrical conduction current; C i Let α represent the fractional capacitance of the i-th polarization branch. i The fractional order (0–1) determines the power law kernel. The shape; τ i The relaxation time constant of the i-th polarization branch; k i These are distributed parameters describing the width of the branch relaxation time distribution and the rate of current tail decay. Each polarization branch has four model parameters (C). i τ i α i k i The system consists of components, and by varying these parameters, the polarization currents of different branches are simulated, thereby characterizing the complex relaxation process in the stator insulation.

4. The method for evaluating the insulation condition of the stator of a high-voltage generator according to claim 3, characterized in that: Based on the calculation of the eigenvalues of Hamilton matrix by phase space reconstruction, the symplectic geometric modal component is constructed by the corresponding eigenvectors, and the original polarization current signal Wherein n is the length of the signal, the trajectory matrix X is obtained by phase space reconstruction of the original signal x, as follows: In the formula, m = n - (d - 1) λ; λ is a delay time; d is an embedding dimension; by selecting the embedding dimension d and the time delay λ, a corresponding trajectory matrix X is obtained; a Hamilton matrix M is obtained according to the trajectory matrix X ; In the formula, A = X T X, square M to get N = M 2 , construct a symplectic orthogonal matrix Q by householder transformation, as follows: 。 5. The method for evaluating the insulation condition of the stator of a high-voltage generator according to claim 4, characterized in that: From the properties of the Hamiltonian matrix, the eigenvalues σ i of A are given by ； The eigenvalues σi are arranged in descending order σ1>σ2>…>σd, the eigenvectors Qi corresponding to these eigenvalues are calculated, and the construction matrix Z is obtained by combining the trajectory matrix X; as follows: 。 6. The method for evaluating the insulation condition of the stator of a high-voltage generator according to claim 5, characterized in that: The reconstruction matrix Z is diagonalized by means of a diagonalization i transformation into a set of time series of length n; define Z i the elements in Z i,j ; after diagonalization according to the above formula, thus Z i is transformed into a set of time series of length n Y i = [y1, y2,..., y n ] wherein when m < d, ; when m > d, .

7. The method for evaluating the insulation condition of the epoxy mica of the stator of a high-voltage generator according to claim 1, characterized in that: In step S5, The polarization current is reconstructed by using samples S1, S2, S3 and S4, and compared with the measured polarization current, as shown in FIG. 5, and the polarization branch number of the measured polarization current is determined; The polarization branch numbers corresponding to samples S1, S2, S3 and S4 are 2, 3, 5 and 6 respectively; after the polarization branch number is determined, the parameters of the MFD model are solved by the RMIA algorithm, and the model parameters of different aging samples; The fitting technology is used for expansion to construct a dielectric characteristic parameter database covering different aging degrees; As follows: 。 8. The method of claim 1, wherein: In step S6, T1, T2, T3 and T4 respectively correspond to the thermal aging time of each characteristic quantity; the inverse function of each fitting equation can be obtained as follows: The measured characteristic quantities are respectively substituted into the above equations to obtain four equivalent aging times, respectively; in order to reduce the uncertainty of a single index, an equal-weight average is used to obtain a comprehensive equivalent aging time, as follows: Wherein, T is the calculated thermal aging time.

9. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the steps of the method for evaluating the insulation state of the epoxy mica of the stator of the high-voltage generator according to any one of claims 1-8 when executing the computer program.

10. A computer storable medium having stored therein a computer program, characterized in that: The program, when executed, sequentially executes the method for evaluating the insulation state of the epoxy mica of the stator of the high-voltage generator according to any one of claims 1-8.

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