A method and device for detecting aging state of oil-paper insulation equipment

Abstract

The present application provides an aging state detection method and device for oil-paper insulation equipment, the method is through obtaining the frequency domain dielectric spectrum FDS test curve of the frequency domain dielectric test equipment. According to the complex dielectric constant relaxation function, the FDS test curve is curve fitted to obtain the test parameters of the complex dielectric constant relaxation function after fitting. Among them, the test parameters are obtained by fitting the complex dielectric constant relaxation function to the FDS test curve. Based on a plurality of preset aging time curves, the corresponding pending aging times of the test parameters are determined. According to the grey correlation analysis method, the correlation coefficient set of each test parameter and the sample parameter corresponding to each aging sample is determined. Through the preset correlation formula, the corresponding correlation degree of each correlation coefficient set is determined, so that the correlation degree that meets the preset conditions and the corresponding correlation coefficient set are used as the correlation weight set. According to the correlation weight set and each pending aging time, the corresponding aging time of the oil-paper insulation equipment to be tested is determined.

Description

Technical Field

[0001] The present application relates to the technical field of electrical equipment safety status assessment, and in particular to an aging status detection method and device for oil-paper insulation equipment. Background Art

[0002] The safety status of electrical equipment is the first line of defense to ensure the safety of the power grid. Oil-immersed power transformers are the core and hub of power transmission and distribution, and are one of the most important and expensive equipment in the power grid. At present, the insulation of large transformers mainly adopts oil-immersed paper composite insulation structure. During the operation of the transformer, the oil-paper insulation structure inside it always bears a high electric field strength. Under the influence of electric field, temperature and other conditions, the oil-paper insulation structure may slightly deteriorate, affecting the normal operation of the transformer.

[0003] In the existing methods for evaluating the insulation status of oil-paper insulation equipment, the evaluation of the degree of polymerization of the insulation paper will cause damage to the insulation structure, and the method of measuring the chemical quantity in the oil cannot properly reflect the insulation status of the insulation structure because it requires oil filtering in the middle. The existing technology usually only studies the moisture content of oil-paper insulation, but there are many factors affecting the aging of oil-paper insulation, and the monitoring results of the aging status have errors.

[0004] Based on this, being able to accurately evaluate the state of oil-paper insulation by considering the aging characteristics of various dielectric response processes without damaging the insulation structure has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present application provide an aging status detection method and device for oil-paper insulation equipment, which are used to accurately and safely detect the aging status of oil-paper insulation.

[0006] On the one hand, the present application provides a method for detecting an aging state of oil-paper insulation equipment, the method comprising:

[0007] Obtain the frequency domain dielectric spectrum FDS test curve of the frequency domain dielectric test equipment. According to the complex dielectric constant relaxation function, curve fitting is performed on the FDS test curve to obtain the test parameters of the complex dielectric constant relaxation function after fitting. Based on the preset multiple aging time curves, the corresponding pending aging times of the test parameters are determined. According to the grey correlation analysis method, the correlation coefficient set of each test parameter and the sample parameter corresponding to each aging sample is determined. The correlation degree corresponding to each correlation coefficient set is determined by the preset correlation formula, so that the correlation degree that meets the preset conditions and the corresponding correlation coefficient set are used as the correlation weight set. According to the correlation weight set and the pending aging time, the corresponding aging time of the oil-paper insulation equipment to be tested is determined.

[0008] In one implementation of the present application, the sum of each correlation coefficient in each correlation coefficient set is determined respectively. The average value of the sum of each correlation coefficient is used as the correlation degree between each test parameter and each aging sample. The correlation coefficient set corresponding to the maximum value in each correlation degree is used as the correlation weight set.

[0009] In one implementation of the present application, a number of aged samples are obtained from a preset sample library. The aging degree of each aged sample is different. The corresponding FDS curve of each aged sample is determined. According to the complex dielectric constant relaxation function, the FDS curve of each aged sample is curve fitted. After the curve fitting of each FDS curve, the parameter values ​​in the complex dielectric constant relaxation function are determined. The aging time of each aged sample is used as the horizontal coordinate, and the parameters of the corresponding type of each test parameter are used as the vertical coordinate to generate each aging time curve of the sample parameters corresponding to each aged sample. The types of test parameters include: low-frequency band conductivity amplitude, low-frequency band conductivity shape parameter, low-frequency band polarization amplitude, and low-frequency band polarization time constant.

[0010] In one implementation of the present application, the numerical values ​​of the sample parameters corresponding to each aging sample are fitted by the least square method, and the curves obtained by fitting the numerical values ​​of the sample parameters corresponding to each aging sample are used as the aging time curves.

[0011] In one implementation of the present application, the FDS test curve is fitted by least square fitting lsqcurvefit function. After the FDS test curve is fitted, the values ​​of each parameter in the complex dielectric constant relaxation function are determined to determine each test parameter in each parameter.

[0012] In one implementation of the present application, the formula of the complex dielectric constant relaxation function is as follows:

[0013]

[0014] Among them, χ * (ω) is the complex dielectric constant function of angular frequency ω. sam is the polarization amplitude. m is the number of dipole polarizations. j is the imaginary unit. τ am is the polarization time constant. am is the asymmetry polarization shape parameter. bm is the flatness polarization shape parameter. l is the conductance amplitude when the DC conductance or jump conductance number is l. l is the conductivity shape parameter.

[0015] In one implementation of the present application, the corresponding pending aging time of each associated weight is determined according to the corresponding relationship between each test parameter and each associated weight in the associated weight set. The product value of each associated weight and the corresponding pending aging time is calculated. The sum of the product values ​​is used as the corresponding aging time of the oil-paper insulation device to be tested.

[0016] In one implementation of the present application, after determining the corresponding aging time of the oil-paper insulation device to be tested, the corresponding test parameters and aging time of the oil-paper insulation device to be tested are used as aging samples to update the preset sample library. Multiple new aging time curves are generated through the updated preset sample library.

[0017] On the other hand, the present application provides an aging state detection device for oil-paper insulation equipment, the device comprising:

[0018] At least one processor; and a memory in communication with the at least one processor. The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to:

[0019] Obtain the frequency domain dielectric spectrum FDS test curve of the frequency domain dielectric test equipment. Wherein, the FDS test curve corresponds to the oil-paper insulation equipment to be tested. According to the complex dielectric constant relaxation function, the FDS test curve is curve fitted to obtain the test parameters of the complex dielectric constant relaxation function after fitting. Wherein, the test parameters are obtained by fitting the complex dielectric constant relaxation function to the FDS test curve. Based on the preset multiple aging time curves, determine the corresponding pending aging times of each test parameter. According to the gray correlation analysis method, determine the correlation coefficient set of each test parameter and the sample parameter corresponding to each aging sample. Determine the corresponding correlation degree of each correlation coefficient set through the preset correlation formula, so as to use the correlation degree that meets the preset conditions and the corresponding correlation coefficient set as the correlation weight set. According to the correlation weight set and the pending aging time, determine the corresponding aging time of the oil-paper insulation equipment to be tested. The aging time is used to characterize the aging degree of the oil-paper insulation equipment to be tested.

[0020] In one implementation of the present application, the processor can specifically:

[0021] The sum of each correlation coefficient in each correlation coefficient set is determined respectively. The average value of the sum of each correlation coefficient is used as the correlation degree between each test parameter and each aging sample. The correlation coefficient set corresponding to the maximum value in each correlation degree is used as the correlation weight set.

[0022] Through the above scheme, the present application can determine the FDS test curve of the oil-paper insulation equipment to be tested, fit the FDS test curve through the complex dielectric constant relaxation function, obtain the corresponding test parameters of the oil-paper insulation equipment to be tested, and then obtain the corresponding pending aging time according to the test parameters; by calculating the correlation between each test parameter and the corresponding parameter of the aging sample, the correlation weight of the pending aging time is obtained, and the aging time of the oil-paper insulation equipment to be tested is determined according to the pending aging time and the correlation weight. By determining the aging state through multiple test parameters, the aging state of the equipment can be accurately detected under multiple influencing factors and multiple aging state parameters, thereby ensuring the accuracy of the aging state detection results. In addition, the detection method of the present application is simple and easy to implement, and the aging state of the equipment can be detected conveniently and efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 A schematic diagram of a flow chart of a method for detecting an aging state of oil-paper insulation equipment in an embodiment of the present application;

[0025] Figure 2 This is a schematic diagram of an aging state detection method for oil-paper insulation equipment in an embodiment of the present application;

[0026] Figure 3 This is a schematic diagram of an aging state detection method for oil-paper insulation equipment in an embodiment of the present application;

[0027] Figure 4 This is a schematic diagram of an aging state detection method for oil-paper insulation equipment in an embodiment of the present application;

[0028] Figure 5 This is a schematic diagram of an aging state detection method for oil-paper insulation equipment in an embodiment of the present application;

[0029] Figure 6 This is a schematic diagram of an aging state detection method for oil-paper insulation equipment in an embodiment of the present application;

[0030] Figure 7 This is a schematic diagram of an aging state detection method for oil-paper insulation equipment in an embodiment of the present application;

[0031] Figure 8 This is a schematic diagram of an aging state detection method for oil-paper insulation equipment in an embodiment of the present application;

[0032] Fig. 9This is a structural schematic diagram of an aging status detection device for oil-paper insulation equipment in an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0034] The aging degree of oil-paper insulation affects the normal service life of the transformer. If the oil-paper insulation structure deteriorates, it is likely to cause transformer failure or even serious accidents such as transformer explosion. At present, the oil-paper insulation structure inside electrical equipment cannot be directly replaced. The aging state of the oil-paper insulation structure basically determines the operating life of the entire electrical equipment. Therefore, the aging state detection and evaluation of the oil-paper insulation structure is of great significance to the safe operation of electrical equipment and the stable operation of the power system.

[0035] There are many factors that affect the aging state of oil-paper insulation structure. Aging will affect multiple dielectric response processes. If the aging state is evaluated based on only a single dielectric response process, it is likely to lead to errors in the evaluation results.

[0036] Based on this, the embodiments of the present application provide an aging status detection method and device for oil-paper insulation equipment, which are used to accurately and safely detect the aging status of oil-paper insulation and accurately evaluate the aging status.

[0037] The following describes in detail various embodiments of the present application in conjunction with the accompanying drawings.

[0038] The present application embodiment provides a method for detecting the aging state of oil-paper insulation equipment. Figure 1 As shown, the method may include steps S101-S105:

[0039] S101: The server obtains a frequency domain dielectric spectrum FDS test curve of a frequency domain dielectric testing device.

[0040] Among them, the FDS test curve corresponds to the oil-paper insulation equipment to be tested.

[0041] In an embodiment of the present application, the high voltage side of the oil-paper insulation device to be tested is connected to the output end of the frequency domain dielectric testing device, and the low voltage side of the oil-paper insulation device to be tested is connected to the input end of the frequency domain dielectric testing device.

[0042] Before the frequency domain dielectric test equipment is connected to the oil-paper insulation equipment to be tested, the high voltage side and the low voltage side of the oil-paper insulation equipment to be tested are short-circuited for a period of time, such as ten minutes, to eliminate the residual charge in the equipment.

[0043] Then, the frequency domain dielectric test equipment is connected to the oil-paper insulation equipment to be tested. The frequency domain dielectric spectrum (FDS) test curve can be obtained through the frequency domain dielectric test equipment. Figure 2 As shown, the horizontal axis is the angular frequency, and the vertical axis is the dielectric spectrum loss curve tanδ obtained by the Havriliak-Negami dielectric relaxation model.

[0044] Among them, the specific formula of tanδ is as follows:

[0045]

[0046] Among them, ε′ is the real part of the relative dielectric constant, ε″ is the imaginary part of the relative dielectric constant, and the relative dielectric constant is: ε(ω)=ε′(ω)-jε″(ω), j is the imaginary unit. The specific formula of the relative dielectric constant is as follows:

[0047]

[0048] Among them, ε ∞ is the high-frequency dielectric constant, j is the imaginary unit, τ is the relaxation time constant, α is the asymmetry polarization shape parameter, β is the flatness polarization shape parameter, the values ​​of α and β are between 0 and 1, Δε is the relaxation intensity, and its expression is: Δε=ε s -ε ∞ , ε s is the static dielectric constant.

[0049] In actual measurement, χ * (ω)=ε(ω)-ε hf , where ε hf is the dielectric constant of the device at optical frequency.

[0050] It should be noted that the server, as an executor of the aging status detection method for oil-paper insulation equipment, is only for example, and the executor is not limited to the server.

[0051] S102: The server performs curve fitting on the FDS test curve according to the complex dielectric constant relaxation function to obtain various test parameters of the fitted complex dielectric constant relaxation function.

[0052] The test parameters are obtained by fitting the complex dielectric constant relaxation function to the FDS test curve.

[0053] In an embodiment of the present application, the server can obtain the parameter values ​​in the complex dielectric constant relaxation function by means of a fitting curve. Specifically, after obtaining the FDS test curve, the server can adjust the parameter values ​​in the complex dielectric constant relaxation function to fit a fitting curve that is consistent with the FDS test curve. When the server obtains the fitting curve, the server can determine the required test parameters from the parameter values ​​in the complex dielectric constant relaxation function corresponding to the fitting curve.

[0054] In one embodiment of the present application, the server may obtain the test parameters in the following manner:

[0055] First, the server fits the FDS test curve through the least squares fitting lsqcurvefit function in MATLAB.

[0056] Then, the server determines the values ​​of each parameter in the complex dielectric constant relaxation function after fitting the FDS test curve to determine each test parameter in each parameter.

[0057] The lsqcurvefit function in MATLAB can save fitting time and speed up the efficiency of aging status detection.

[0058] In this application, the specific formula of the complex dielectric constant relaxation function is as follows:

[0059]

[0060] Among them, χ * (ω) is the complex dielectric constant function of angular frequency ω; X saj is the polarization amplitude in the high frequency band; m is the number of dipole polarizations; j is the imaginary unit; τ am is the polarization time constant; n am is the asymmetry polarization shape parameter; n bm is the flatness polarization shape parameter; A l is the conductance amplitude when the DC conductance or jump conductance number is l; n l is the conductivity shape parameter.

[0061] In this application, before the server determines each pending aging time corresponding to each test parameter, it is necessary to establish a corresponding relationship between the parameters corresponding to the test parameter and the aging time, that is, an aging time curve, so as to obtain the pending aging time through the test parameter. This application obtains the aging time curve by executing the following method, and the specific steps are as follows:

[0062] First, the server obtains several aging samples from a preset sample library.

[0063] Among them, the aging degree of each aging sample is different.

[0064] For example, the server may obtain from the preset sample library several aging samples with aging times of 0 hours, 50 hours, 100 hours, 200 hours, etc. The preset sample library may contain several samples with different aging degrees.

[0065] Next, the server determines the corresponding FDS curve for each aged sample.

[0066] Next, the server performs curve fitting on the FDS curve of each aged sample according to the complex dielectric constant relaxation function. This step is the same as the above S102 and will not be described again here.

[0067] Then, the server determines the parameter values ​​in the complex dielectric constant relaxation function after curve fitting of each FDS curve. This step is the same as the above S102 and will not be described again here.

[0068] Finally, the aging time of each aging sample is used as the horizontal coordinate, and the parameters of the corresponding type of each test parameter are used as the vertical coordinate to generate each aging time curve of the sample parameters corresponding to each aging sample.

[0069] Among them, the types of test parameters include: low-frequency band conductance amplitude, low-frequency band conductance shape parameter, low-frequency band polarization amplitude, and low-frequency band polarization time constant.

[0070] The type of sample parameters corresponds to the type of test parameters, and the sample parameter types also include: low-frequency conductance amplitude, low-frequency conductance shape parameter, low-frequency polarization amplitude, and low-frequency polarization time constant.

[0071] In the embodiment of the present application, the low-frequency band conductance amplitude A1, the low-frequency band conductance shape parameter n1, the low-frequency band polarization amplitude X sa2 , low frequency polarization time constant τ a2 As the ordinate of each aging time curve, Figure 3 The aging time curve of the low-frequency conductance amplitude A1 and the aging time, Figure 4 is the aging time curve of the low-frequency conductivity shape parameter n1 and the aging time, Figure 5 is the low frequency polarization amplitude X sa2 The aging time curve corresponding to the aging time, Figure 6 is the low frequency polarization time constant τ a2 Aging time curve corresponding to the aging time.

[0072] in, Figure 3 , Figure 4 , Figure 5 , Figure 6 The solid lines in the figure are the relationship between the parameter values ​​of the aging samples with different aging degrees and the test parameters and the aging time. Figure 3In the figure, the aging time is 200 hours, and the corresponding low-frequency conductance amplitude A1 is 0.022.

[0073] In one embodiment of the present application, the server may also fit the values ​​of the sample parameters corresponding to each aging sample by using the least square method.

[0074] The server uses the curve obtained by numerically fitting the sample parameters corresponding to each aging sample as each aging time curve.

[0075] Figure 3 , Figure 4 , Figure 5 , Figure 6 The dotted line in the figure is the value of the parameter corresponding to the aging sample. Compared with the solid line in the figure, the fitted straight line can more accurately characterize the relationship between the aging time and each test parameter, which can further ensure the accuracy of the aging status detection results.

[0076] In addition, the aging sample in the present application may be a sequence stored in a sample library, wherein the sequence includes: low-frequency band conductance amplitude A1, low-frequency band conductance shape parameter n1, low-frequency band polarization amplitude X sa2 , low frequency polarization time constant τ a2 The corresponding relationships with the aging time are shown in the following table:

[0077] Aging time <![CDATA[A1]]> <![CDATA[n1]]> <![CDATA[X sa2 ]]> <![CDATA[τ a2 ]]> 0h 0.00768 0.70049 4.18029 12066.21 50h 0.00762 0.68523 3.89821 11999.57 100h 0.01261 0.66229 5.1002 12057.62 200h 0.02173 0.61672 8.45773 11900.04 300h 0.04489 0.553 10.29216 11746.32 400h 0.04194 0.51209 10.82449 11498.64 500h 0.0475 0.49903 12.03135 11429.79 600h 0.06411 0.47662 13.78901 11238.59 700h 0.0752 0.45564 14.69714 11301.83 800h 0.08845 0.42421 16.17156 11295.78

[0078] The above table lists ten sequences. It is known to those skilled in the art that by using a larger number of aging samples to generate an aging time curve, the aging time curve can be more accurate and closer to the relationship between the aging state of the oil-paper insulation equipment and the test parameters during actual use.

[0079] S103: The server determines each pending aging time corresponding to each test parameter based on a plurality of preset aging time curves.

[0080] In the embodiment of the present application, the server sequentially substitutes the obtained test parameters into the aging time curves to obtain the aging times to be determined. For example, the test parameter low-frequency band conductance amplitude A1=0.011 is substituted into Figure 3 In the corresponding functional relationship of the aging time curve in, the horizontal coordinate value of the aging time curve can be obtained, such as 165 hours (such as Figure 7 , the actual extraction result of the star symbol); for example, substituting the low-frequency band conductivity shape parameter n1 = 0.66 into Figure 4 Aging time curve in 170 hours (such as Figure 8 , the star symbol is the actual extraction result). Substituting the four test parameters into each aging time curve in turn, four undetermined aging times can be obtained.

[0081] S104: The server determines a set of correlation coefficients between each test parameter and a sample parameter corresponding to each aging sample according to a grey correlation analysis method.

[0082] In the embodiment of the present application, the grey correlation analysis formula is as follows:

[0083]

[0084] Among them, η i (k) is the comparison sequence x i That is, the correlation coefficient of the i-th aging sample to the k-th test parameter of the reference sequence x0, i represents the number of aging samples, Min i Min k |x i (k)-x0(k)| is the minimum difference between the two levels, Max i Max k |x i (k)-x0(k)| is the maximum difference between the two levels, and λ is the resolution coefficient.

[0085] The server can obtain i*k correlation coefficients through the above grey correlation analysis method. According to different aging samples, i sets of correlation coefficients containing k elements can be obtained. For example, the above ten sets of sequences are aging samples with four test parameters. The server can obtain ten sets of correlation coefficients containing four test parameters.

[0086] S105: The server determines the corresponding correlation of each correlation coefficient set by using a preset correlation formula, and uses the correlation coefficient set corresponding to the correlation that meets the preset conditions as the correlation weight set.

[0087] In the embodiment of the present application, the server can calculate the correlation degree corresponding to the correlation coefficient through the correlation degree formula. The correlation degree formula is as follows:

[0088]

[0089] Among them, γ i is the correlation between the i-th aging sample and each test parameter; n is the number of test parameters; k is the k-th test parameter; η i (k) is the correlation coefficient between the i-th aging sample and the k-th test parameter.

[0090] Through the above correlation formula, we can get i correlations between the test parameters of the oil-paper insulation equipment to be tested and the corresponding parameters in the aging sample. The server can convert the i correlations γ i Among them, the largest value of γ i As the correlation degree that satisfies a preset condition, or the preset condition is that the correlation degree is greater than a preset threshold.

[0091] In the embodiment of the present application, after the server determines the association degree that meets the preset conditions, it determines its corresponding association coefficient set, and the server uses the association coefficient set as the association weight set.

[0092] S106: The server determines the corresponding aging time of the oil-paper insulation device to be tested according to the associated weight set and each pending aging time.

[0093] Among them, the aging time is used to characterize the aging degree of the oil-paper insulation equipment to be tested.

[0094] In the embodiment of the present application, the server can obtain the corresponding aging time of the oil-paper insulation device to be tested by associating the weight set and each pending aging time.

[0095] The server determines the pending aging time corresponding to each associated weight according to the corresponding relationship between each test parameter and each associated weight in the associated weight set. Then, the product value of each associated weight and the corresponding pending aging time is calculated. The server uses the sum of the product values ​​as the corresponding aging time of the oil-paper insulation device to be tested.

[0096] For example, the associated weight set is: (η1, η2, η3, η4), and the corresponding pending aging times of the test parameters of the oil-paper insulation equipment to be tested are: T1, T2, T3, T4, and the server can obtain the aging time T0 of the oil-paper insulation equipment to be tested as:

[0097] T0=η1·T1+η2·T2+η3T3+η4T4

[0098] In one embodiment of the present application, after determining the corresponding aging time of the oil-paper insulation device to be tested, the server may use the corresponding test parameters and aging time of the oil-paper insulation device to be tested as aging samples to update the preset sample library.

[0099] The server generates multiple new aging time curves through the updated preset sample library.

[0100] This application can ensure the update of the aging state detection method by updating the aging time curve, so that this application can be more suitable for the actual measurement environment and avoid detection errors in actual measurement.

[0101] The present application determines the FDS test curve of the oil-paper insulation equipment to be tested through the above scheme, fits the FDS test curve through the complex dielectric constant relaxation function, obtains the corresponding test parameters of the oil-paper insulation equipment to be tested, and then obtains the corresponding pending aging time according to the test parameters; by calculating the correlation between each test parameter and the corresponding parameter of the aging sample, the correlation weight of the pending aging time is obtained, and the aging time of the oil-paper insulation equipment to be tested is determined according to the pending aging time and the correlation weight.

[0102] The present application can accurately obtain the aging state of the oil-paper insulation equipment through multiple test parameters that affect the aging state of the oil-paper insulation equipment. Moreover, the present application will not damage the oil-paper insulation equipment, and the aging state detection method is easy to operate.

[0103] Fig. 9 An aging state detection device for oil-paper insulation equipment provided in an embodiment of the present application includes:

[0104] At least one processor; and a memory in communication with the at least one processor. The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to:

[0105] Obtain the frequency domain dielectric spectrum FDS test curve of the frequency domain dielectric test equipment. Wherein, the FDS test curve corresponds to the oil-paper insulation equipment to be tested. According to the complex dielectric constant relaxation function, the FDS test curve is curve fitted to obtain the test parameters of the complex dielectric constant relaxation function after fitting. Wherein, the test parameters are obtained by fitting the complex dielectric constant relaxation function to the FDS test curve. Based on the preset multiple aging time curves, determine the corresponding pending aging times of each test parameter. According to the gray correlation analysis method, determine the correlation coefficient set of each test parameter and the parameter corresponding to each aging sample. Through the preset correlation formula, determine the corresponding correlation degree of each correlation coefficient set, so as to use the correlation degree that meets the preset conditions and the corresponding correlation coefficient set as the correlation weight set. According to the correlation weight set and the pending aging time, determine the corresponding aging time of the oil-paper insulation equipment to be tested. The aging time is used to characterize the aging degree of the oil-paper insulation equipment to be tested.

[0106] In the embodiment of the present application, the processor can specifically:

[0107] The sum of each correlation coefficient in each correlation coefficient set is determined respectively. The average value of the sum of each correlation coefficient is used as the correlation degree between each test parameter and each aging sample. The correlation coefficient set corresponding to the maximum value in each correlation degree is used as the correlation weight set.

[0108] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0109] The device and method provided in the embodiments of the present application correspond one to one, and therefore, the device also has similar beneficial technical effects as its corresponding method. Since the beneficial technical effects of the method have been described in detail above, the beneficial technical effects of the device will not be repeated here.

[0110] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0111] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A method for detecting the aging state of oil-paper insulation equipment, characterized in that: The high voltage side of the oil-paper insulation device to be tested is connected to the output end of the frequency domain dielectric test device, and the low voltage side of the oil-paper insulation device to be tested is connected to the input end of the frequency domain dielectric test device; the method comprises: Obtain a frequency domain dielectric spectrum FDS test curve of the frequency domain dielectric testing equipment; According to the complex dielectric constant relaxation function, the FDS test curve is curve fitted to obtain the test parameters of the complex dielectric constant relaxation function after fitting; Based on a plurality of preset aging time curves, determining respective pending aging times corresponding to the respective test parameters; Determine the correlation coefficient set between each of the test parameters and the sample parameters corresponding to each aging sample according to the grey correlation analysis method; Determine the correlation degree corresponding to each of the correlation coefficient sets by using a preset correlation degree formula, so as to use the correlation degree that meets the preset conditions and the corresponding correlation coefficient set as the correlation weight set; Determining the corresponding aging time of the oil-paper insulation device to be tested according to the association weight set and each of the pending aging times; Wherein, before determining each pending aging time corresponding to each of the test parameters based on a plurality of preset aging time curves, the method further includes: Acquire a plurality of aging samples in a preset sample library; wherein the aging degrees of the aging samples are different; Determine the FDS curve corresponding to each of the aged samples; Performing curve fitting on the FDS curve of each of the aged samples according to the complex dielectric constant relaxation function; Determining the values ​​of each parameter in the complex dielectric constant relaxation function after curve fitting of each of the FDS curves; Taking the aging time of each aging sample as the abscissa and the parameters of the corresponding type of each test parameter as the ordinate, generating the aging time curves of the sample parameters corresponding to each aging sample; wherein the types of the test parameters include: low-frequency conductance amplitude, low-frequency conductance shape parameter, low-frequency polarization amplitude, and low-frequency polarization time constant; Wherein, determining the corresponding aging time of the oil-paper insulation device to be tested according to the association weight set and each of the pending aging times specifically includes: Determining the pending aging time corresponding to each of the association weights according to the corresponding relationship between each of the test parameters and each of the association weights in the association weight set; Calculating the product value of each of the association weights and the corresponding pending aging time; The sum of the product values ​​is used as the corresponding aging time of the oil-paper insulation device to be tested; The correlation formula is as follows: Among them, γ i is the correlation between the i-th aging sample and each test parameter; n is the number of test parameters; k is the k-th test parameter; η i (k) is the correlation coefficient between the i-th aged sample and the k-th test parameter; Through the above correlation formula, we can get the i correlations between the test parameters of the oil-paper insulation equipment to be tested and the corresponding parameters in the aging sample, and convert the i correlations γ i Among them, the largest value of γ i As the degree of association that meets the preset conditions; After determining the association degree that meets the preset conditions, determine its corresponding association coefficient set, and use the association coefficient set as the association weight set; Among them, the associated weight set is: (η1, η2, η3, η4), the corresponding undetermined aging times of the test parameters of the oil-paper insulation equipment to be tested are: T1, T2, T3, T4, and the aging time T0 of the oil-paper insulation equipment to be tested is: T0=eta1·T1+eta2·T2+eta3T3+eta4T4; The correlation degree corresponding to each of the correlation coefficient sets is determined by a preset correlation formula, so that the correlation degree that satisfies the preset conditions and the corresponding correlation coefficient set are used as the correlation weight set, specifically including: Determine the sum of each correlation coefficient in each correlation coefficient set respectively; Taking the average value of the sum of the correlation coefficients as the correlation degree between each test parameter and each aging sample; The association coefficient set corresponding to the maximum value of each of the association degrees is used as the association weight set; The step of generating the aging time curves of the corresponding parameters of the aging samples specifically includes: Fitting the values ​​of the sample parameters corresponding to each of the aging samples by the least square method; Using a curve obtained by numerically fitting the sample parameters corresponding to each of the aging samples as each of the aging time curves; Among them, according to the complex dielectric constant relaxation function, the FDS test curve is curve fitted to obtain the test parameters of the complex dielectric constant relaxation function after fitting, specifically including: Fitting the FDS test curve by least squares fitting lsqcurvefit function; Determine the parameter values ​​of the complex dielectric constant relaxation function after fitting the FDS test curve to determine the test parameters of the parameters; Wherein, the formula of the complex dielectric constant relaxation function is as follows: Among them, χ * is the complex dielectric constant function of angular frequency ω; X sam is the polarization amplitude; m is the number of dipole polarizations; j is the imaginary unit; τ am is the polarization time constant; n am is the asymmetry polarization shape parameter; n bm is the flatness polarization shape parameter; A l is the conductance amplitude when the DC conductance or jump conductance number is l; n l is the conductivity shape parameter; Wherein, the method further comprises: After determining the corresponding aging time of the oil-paper insulation device to be tested, taking the corresponding test parameters and the aging time of the oil-paper insulation device to be tested as aging samples to update the preset sample library; A plurality of new aging time curves are generated through the updated preset sample library.

2. An aging state detection device for oil-paper insulation equipment, characterized in that: The device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the aging status detection method for oil-paper insulation equipment as described in claim 1 above.

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