Method for distinguishing silicone rubber for composite insulator

Abstract

The invention discloses a distinguishing method of silicone rubber for a composite insulator. At least two silicone rubber for the composite insulator are provided. The distinguishing method for the silicone rubber for the composite insulator comprises the following steps: carrying out thermogravimetric-infrared combined test on the silicone rubber for each composite insulator to obtain spectrum information of the silicone rubber for each composite insulator; and distinguishing the difference of the silicone rubber for each composite insulator according to the atlas information of the silicone rubber for each composite insulator. By adopting the method for distinguishing the silicone rubber for the composite insulator, whether a production formula of the silicone rubber for the composite insulator is changed or not and whether the silicone rubber for the composite insulator is a renovated product or not can be distinguished, and the method has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the field of high voltage, and in particular to a method for distinguishing silicone rubber used in composite insulators. Background Art

[0002] Due to its hydrophobic migration properties, silicone rubber has become a key raw material for preventing flashover in high-voltage transmission lines. Composite insulators using silicone rubber as the key external insulation material now account for one-third of all insulators in power grids. With the increasing use of silicone rubber in the power industry, the need for regulatory oversight of material reliability is increasing. If a large number of low-quality insulators were to enter the power grid, it would pose a significant risk to the safe and stable operation of the grid. However, current testing methods for silicone rubber used in composite insulators cannot distinguish whether the production formula of the silicone rubber used in composite insulators has changed or whether the silicone rubber used in composite insulators is refurbished. Summary of the Invention

[0003] The invention provides a method for distinguishing silicone rubber for composite insulators, which can distinguish whether the production formula of the silicone rubber for composite insulators has changed and whether the silicone rubber for composite insulators is a refurbished product.

[0004] An embodiment of the present invention provides a method for distinguishing silicone rubber for composite insulators, including at least two silicone rubbers for composite insulators. The method comprises the following steps: performing a thermogravimetric-infrared combined test on each silicone rubber for composite insulators to obtain spectral information of each silicone rubber for composite insulators; and distinguishing differences between the silicone rubbers for composite insulators based on the spectral information of each silicone rubber for composite insulators.

[0005] In some embodiments, obtaining the spectrum information of the silicone rubber for each composite insulator includes obtaining a mass-time curve graph and an infrared spectrum intensity-time curve graph of the silicone rubber for each composite insulator.

[0006] In some embodiments, obtaining the spectral information of each silicone rubber for composite insulators further includes: determining the characteristic temperature of each silicone rubber for composite insulators based on the mass-time curve and the infrared spectrum intensity-time curve of each silicone rubber for composite insulators, and obtaining the absorbance-wavenumber infrared spectrum curve of each silicone rubber for composite insulators at its characteristic temperature.

[0007] In some embodiments, the characteristic temperature of each silicone rubber for composite insulators is determined based on the mass-time curve graph and the infrared spectrum intensity-time curve graph of each silicone rubber for composite insulators, including: obtaining the temperature corresponding to the decomposition starting position in the mass-time curve graph of each silicone rubber for composite insulators and the temperature corresponding to the peak position in the infrared spectrum intensity-time curve graph as the characteristic temperature of each silicone rubber for composite insulators.

[0008] In some embodiments, distinguishing differences between silicone rubbers for composite insulators based on spectral information of each silicone rubber for composite insulator includes: constructing a spectral data vector for each silicone rubber for composite insulator at its characteristic temperature based on an absorbance-wavenumber infrared spectrum curve of each silicone rubber for composite insulator at its characteristic temperature; constructing a feature matrix for each silicone rubber for composite insulator based on the spectral data vector for each silicone rubber for composite insulator at its characteristic temperature; obtaining similarities between the feature matrices of each silicone rubber for composite insulator based on the feature matrices of each silicone rubber for composite insulator; and distinguishing differences between silicone rubbers for composite insulators based on the similarities between the feature matrices of each silicone rubber for composite insulator.

[0009] In some embodiments, a characteristic matrix of each silicone rubber for composite insulators is constructed based on the spectral data vector of each silicone rubber for composite insulators at its characteristic temperature, including: constructing the characteristic matrix of each silicone rubber for composite insulators based on the spectral data vector of each silicone rubber for composite insulators at its characteristic temperature after removing noise.

[0010] In some embodiments, the noise includes a spectrum data vector corresponding to a negative value of a characteristic peak of carbon dioxide.

[0011] In some embodiments, obtaining the similarity of the characteristic matrices of the silicone rubbers for composite insulators according to the characteristic matrices of the silicone rubbers for composite insulators includes: calculating the similarity of the characteristic matrices of two silicone rubbers for composite insulators using the following formula; Where ρ is the similarity, and X and X' are the characteristic matrices of two silicone rubber composite insulators.

[0012] In some embodiments, differences between the silicone rubbers for composite insulators are identified based on similarities in their feature matrices, including: when the similarity in the feature matrices of two silicone rubbers for composite insulators is greater than 0.99, determining that there is no significant difference between the two silicone rubbers for composite insulators; and when the similarity in the feature matrices of two silicone rubbers for composite insulators is less than 0.95, determining that there is a significant difference between the two silicone rubbers for composite insulators.

[0013] In some embodiments, before performing the thermogravimetric-infrared combined test on each silicone rubber for composite insulators, the test baseline of the thermogravimetric-infrared combined test is calibrated and a blank test of the thermogravimetric-infrared combined test is performed.

[0014] According to an embodiment of the present invention, a method for distinguishing silicone rubber for composite insulators is provided, which has at least two silicone rubbers for composite insulators. The method for distinguishing silicone rubber for composite insulators includes the following steps: performing a thermogravimetric-infrared test on each silicone rubber for composite insulator to obtain spectral information of each silicone rubber for composite insulator. Based on the spectral information of each silicone rubber for composite insulator, the differences between the silicone rubbers for composite insulators are distinguished. By adopting the method for distinguishing silicone rubber for composite insulators of the present invention, it is possible to distinguish whether the production formula of the silicone rubber for composite insulators has changed and whether the silicone rubber for composite insulators is a refurbished product, and the method has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 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 those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 The mass-time curve and infrared spectrum intensity-time curve of the high-temperature vulcanized silicone rubber in the embodiment of the present invention are shown;

[0017] Figure 2 This is an absorbance-wavenumber infrared spectrum curve of the high-temperature vulcanized silicone rubber at 260° C. in an embodiment of the present invention;

[0018] Figure 3 This is an absorbance-wavenumber infrared spectrum curve of the high-temperature vulcanized silicone rubber at 390° C. in an embodiment of the present invention;

[0019] Figure 4 This is an absorbance-wavenumber infrared spectrum curve of the high-temperature vulcanized silicone rubber at 550°C in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] In view of the current difficulties in detecting the material properties of silicone rubber for composite insulators, an embodiment of the present invention provides a method for distinguishing silicone rubber for composite insulators, involving at least two silicone rubbers for composite insulators and comprising two steps, namely the following steps (1) and (2):

[0022] Step (1): Perform a thermogravimetric-infrared combined test on the silicone rubber for each composite insulator to obtain the atlas information of the silicone rubber for each composite insulator.

[0023] In the above step (1), it should be noted that the main types of silicone rubber used for composite insulators include room temperature vulcanized silicone rubber and high temperature vulcanized silicone rubber. Although the two types of products differ in process and fillers, the main components of the raw rubber are not much different, so the testing method can use the same method.

[0024] Before performing the thermogravimetric-infrared combined test on the silicone rubber for each composite insulator, the test baseline of the thermogravimetric-infrared combined test is calibrated and a blank test of the thermogravimetric-infrared combined test is carried out.

[0025] Thermogravimetric-infrared combined testing was performed on the silicone rubber for each composite insulator, including two processes, namely the following processes (a1) and (a2):

[0026] Process (a1): Cut a specimen of the size suitable for the crucible from each silicone rubber sample for composite insulators.

[0027] Procedure (a2): The test is carried out with nitrogen as the atmosphere and the set temperature rise rate.

[0028] In the above process (a2), the set temperature rise rate can be 20°C / min, or 30°C / min, 40°C / min, etc., and is not limited to this.

[0029] Obtaining the atlas information of silicone rubber for each composite insulator includes two processes, namely the following processes (b1) and (b2):

[0030] Process (b1): Obtain a mass-time curve diagram and an infrared spectrum intensity-time curve diagram of the silicone rubber for each composite insulator.

[0031] Process (b2): Based on the mass-time curve and infrared spectrum intensity-time curve of each silicone rubber for composite insulators, the characteristic temperature of each silicone rubber for composite insulators is determined, and the absorbance-wavenumber infrared spectrum curve of each silicone rubber for composite insulators at its characteristic temperature is obtained.

[0032] In the above process (b2), determining the characteristic temperature of each composite insulator silicone rubber based on the mass-time curve and infrared spectrum intensity-time curve of each composite insulator silicone rubber includes obtaining the temperature corresponding to the decomposition starting position in the mass-time curve of each composite insulator silicone rubber and the temperature corresponding to the peak position in the infrared spectrum intensity-time curve as the characteristic temperature of each composite insulator silicone rubber. If a composite insulator silicone rubber has multiple characteristic temperatures, the composite insulator silicone rubber has multiple absorbance-wavenumber infrared spectrum curves corresponding to the characteristic temperatures.

[0033] Step (2): Based on the atlas information of the silicone rubber for each composite insulator, the differences between the silicone rubber for each composite insulator are identified.

[0034] The above step (2) includes four processes, namely the following processes (c1), (c2), (c3), and (c4):

[0035] Process (c1): Based on the absorbance-wavenumber infrared spectrum curve of each silicone rubber for composite insulators at its characteristic temperature, a spectrum data vector of each silicone rubber for composite insulators at its characteristic temperature is constructed.

[0036] In the above process (c1), when there are multiple absorbance-wavenumber infrared spectrum curves of a silicone rubber for composite insulators at its characteristic temperature, there are multiple spectrum data vectors of the silicone rubber for composite insulators at its characteristic temperature, which correspond to each other and can be respectively recorded as x1, x2...x n .

[0037] Process (c2): constructing a characteristic matrix of each silicone rubber for composite insulators based on the spectrum data vector of each silicone rubber for composite insulators at its characteristic temperature.

[0038] In the above process (c2), the characteristic matrix of each composite insulator silicone rubber is constructed based on the noise-removed spectrum data vector of each composite insulator silicone rubber at its characteristic temperature. The noise includes the spectrum data vector corresponding to the negative value of the carbon dioxide characteristic peak. The spectrum data of a composite insulator silicone rubber at its characteristic temperature is x1, x2...x n When the characteristic matrix of the silicone rubber for composite insulator is X={x1, x2...x n}.

[0039] It should be noted that, the characteristic matrix of each silicone rubber for composite insulators can be used to draw a thermogravimetric-infrared combined test characteristic spectrum of each silicone rubber for composite insulators.

[0040] Process (c3): according to the feature matrix of each silicone rubber for composite insulators, obtaining the similarity of the feature matrix of each silicone rubber for composite insulators.

[0041] In the above process (c3), the similarity of the characteristic matrices of the two silicone rubber composite insulators is calculated using the following formula:

[0042]

[0043] Where ρ is the similarity, and X and X' are the characteristic matrices of two silicone rubber composite insulators.

[0044] The above process obtains a similarity calculation formula by calculating the Frobenius dot product and norm of X and X'. X and X' can be the feature matrix of a type of composite insulator silicone rubber obtained initially and the feature matrix of the same type of composite insulator silicone rubber obtained again, respectively.

[0045] Process (c4): Based on the similarity of the characteristic matrices of the silicone rubber for composite insulators, the differences between the silicone rubber for composite insulators are identified.

[0046] In the above process (c4), when the similarity of the feature matrices of the two silicone rubber composite insulators is greater than 0.99, it is determined that there is no significant difference between the two silicone rubber composite insulators. When the similarity of the feature matrices of the two silicone rubber composite insulators is less than 0.95, it is determined that there is a significant difference between the two silicone rubber composite insulators.

[0047] The present invention is described in detail below using high-temperature vulcanized silicone rubber, which is common among silicone rubbers for composite insulators, as an example:

[0048] Obtain a model of high-temperature vulcanized silicone rubber, calibrate the test baseline of the thermogravimetric-infrared test and conduct a blank test of the thermogravimetric-infrared test. Cut a specimen that fits the crucible size from the high-temperature vulcanized silicone rubber sample, perform a thermogravimetric-infrared test on the high-temperature vulcanized silicone rubber in a nitrogen atmosphere at a temperature rise rate of 20°C / min, and obtain the mass-time curve and infrared spectrum intensity-time curve of the high-temperature vulcanized silicone rubber, as shown in the figure. Figure 1 As shown, from Figure 1 It can be seen that the mass-time curve has three steps and the infrared spectrum intensity-time curve has two peaks.

[0049] Obtain the temperature 260°C corresponding to the decomposition starting position in the mass-time curve of high-temperature vulcanized silicone rubber and the temperatures 390°C and 550°C corresponding to the two peak positions in the infrared spectrum intensity-time curve. Obtain the absorbance-wavenumber infrared spectrum curves of high-temperature vulcanized silicone rubber at 260°C, 390°C and 550°C, such as Figure 2-4 As shown by Figure 2 It can be seen that at 2600cm -1 -2800cm -1 The characteristic peak of carbon dioxide in this wavenumber range is negative, indicating that this part is greatly affected by factors such as the sealing of the equipment and is greatly disturbed by the external environment, and is noise that affects the test accuracy.

[0050] According to the absorbance-wavenumber infrared spectrum curves of high temperature vulcanized silicone rubber at 260℃, 390℃ and 550℃, the spectrum data vectors of high temperature vulcanized silicone rubber at 260℃, 390℃ and 550℃ were constructed. -1-2800cm -1 The spectrum data vector x1 of this wave number range, high temperature vulcanized silicone rubber at 390℃ removes 2600cm -1 -2800cm -1 The spectrum data vector x2 in this wavenumber range and the high temperature vulcanized silicone rubber at 550℃ removed 2600cm -1 -2800cm -1 The spectrum data vector x3 of this wavenumber range is used to construct the characteristic matrix X = {x1, x2, x3} of high-temperature vulcanized silicone rubber. The characteristic matrix X can be used to characterize the thermogravimetric-infrared test characteristic spectrum of high-temperature vulcanized silicone rubber.

[0051] After obtaining the same type of high temperature vulcanized silicone rubber again, the characteristic matrix X' of the same type of high temperature vulcanized silicone rubber is obtained according to the above method.

[0052] Using the formula Calculate the similarity ρ of the characteristic matrices of the two high-temperature vulcanized silicone rubbers. If the similarity ρ is greater than 0.99, the two high-temperature vulcanized silicone rubbers are considered to have no significant differences. If the similarity ρ is less than 0.95, the two high-temperature vulcanized silicone rubbers are considered to have significant differences. The manufacturer of the re-acquired high-temperature vulcanized silicone rubber must provide an explanation or conduct additional testing to verify the reliability of the re-acquired high-temperature vulcanized silicone rubber.

[0053] The method for distinguishing silicone rubber for composite insulators of the present invention can help front-line power workers to simply and accurately distinguish whether the production formula of silicone rubber for composite insulators has changed and whether the silicone rubber for composite insulators is a refurbished product. It also solves the problem of long-term reliability testing of silicone rubber for composite insulators and has broad application prospects.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for distinguishing silicone rubber for composite insulators, comprising at least two silicone rubbers for composite insulators; characterized in that: The method for distinguishing silicone rubber for composite insulators comprises the following steps: Performing a thermogravimetric-infrared combined test on each silicone rubber for composite insulators to obtain atlas information of the silicone rubber for each composite insulator; According to the atlas information of the silicone rubber for each composite insulator, the differences between the silicone rubber for each composite insulator are identified.

2. The method for distinguishing silicone rubber for composite insulators according to claim 1, wherein: Obtaining the atlas information of the silicone rubber for each composite insulator, including: Obtain a mass-time curve diagram and an infrared spectrum intensity-time curve diagram of the silicone rubber for each composite insulator.

3. The method for distinguishing silicone rubber for composite insulators according to claim 2, wherein: Obtaining the atlas information of the silicone rubber for each composite insulator further includes: According to the mass-time curve and infrared spectrum intensity-time curve of each silicone rubber for composite insulators, the characteristic temperature of each silicone rubber for composite insulators is determined, and the absorbance-wavenumber infrared spectrum curve of each silicone rubber for composite insulators at its characteristic temperature is obtained.

4. The method for distinguishing silicone rubber for composite insulators according to claim 3, wherein: Determining the characteristic temperature of each silicone rubber for composite insulators according to a mass-time curve graph and an infrared spectrum intensity-time curve graph of each silicone rubber for composite insulators includes: The temperature corresponding to the decomposition starting position in the mass-time curve of the silicone rubber for each composite insulator and the temperature corresponding to the peak position in the infrared spectrum intensity-time curve are obtained as the characteristic temperature of the silicone rubber for each composite insulator.

5. The method for distinguishing silicone rubber for composite insulators according to claim 3, wherein: According to the atlas information of the silicone rubber for each composite insulator, the differences between the silicone rubber for each composite insulator are distinguished, including: constructing a spectrum data vector of each silicone rubber for composite insulators at its characteristic temperature according to an absorbance-wavenumber infrared spectrum curve graph of each silicone rubber for composite insulators at its characteristic temperature; constructing a characteristic matrix of each silicone rubber for composite insulators according to the spectrum data vectors of each silicone rubber for composite insulators at its characteristic temperature; Obtaining similarities of the characteristic matrices of the silicone rubbers for composite insulators according to the characteristic matrices of the silicone rubbers for composite insulators; According to the similarity of the characteristic matrices of the silicone rubbers for composite insulators, the differences between the silicone rubbers for composite insulators are identified.

6. The method for distinguishing silicone rubber for composite insulators according to claim 5, wherein: According to the spectrum data vectors of the silicone rubber for composite insulators at their characteristic temperatures, a characteristic matrix of the silicone rubber for composite insulators is constructed, including: A characteristic matrix of the silicone rubber for composite insulators is constructed based on the spectral data vector of the noise-removed silicone rubber for composite insulators at the characteristic temperature.

7. The method for distinguishing silicone rubber for composite insulators according to claim 6, wherein: The noise includes a spectrum data vector corresponding to a negative value of a characteristic peak of carbon dioxide.

8. The method for distinguishing silicone rubber for composite insulators according to claim 5, wherein: Obtaining similarities of the characteristic matrices of the silicone rubbers for composite insulators according to the characteristic matrices of the silicone rubbers for composite insulators includes: The similarity of the characteristic matrices of two silicone rubber composite insulators is calculated using the following formula; Wherein, ρ is the similarity; X and X' are the characteristic matrices of the two silicone rubbers for composite insulators.

9. The method for distinguishing silicone rubber for composite insulators according to claim 8, wherein: According to the similarity of the characteristic matrices of the silicone rubbers for composite insulators, the differences between the silicone rubbers for composite insulators are distinguished, including: When the similarity of the characteristic matrices of the two silicone rubbers for composite insulators is greater than 0.99, it is determined that there is no obvious difference between the two silicone rubbers for composite insulators; when the similarity of the characteristic matrices of the two silicone rubbers for composite insulators is less than 0.95, it is determined that there is an obvious difference between the two silicone rubbers for composite insulators.

10. The method for distinguishing silicone rubber for composite insulators according to claim 1, wherein: Before performing the thermogravimetric-infrared combined test on the silicone rubber for each composite insulator, the test baseline of the thermogravimetric-infrared combined test is calibrated and a blank test of the thermogravimetric-infrared combined test is carried out.

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