Insulating dielectric breakdown size effect prediction method and application thereof

Abstract

The invention discloses an insulating dielectric breakdown size effect prediction method and application thereof, and belongs to the technical field of insulation, and the method comprises the steps: obtaining the respective mixed distribution model of a plurality of large-size dielectrics of different sizes, calculating the overall breakdown strength of each large-size dielectric based on the mixed distribution model, and calculating the overall breakdown strength of each large-size dielectric; calculating to obtain a size effect curve of the dielectric breakdown strength changing along with the size; the acquisition mode of the mixed distribution model comprises the following steps: selecting a plurality of small-size dielectrics with the same size, respectively determining the breakdown strength, and obtaining the number of breakdown peaks and the breakdown strength range corresponding to each breakdown peak through frequency analysis; determining a breakdown strength probability distribution form corresponding to each breakdown peak according to the breakdown strength range, and fitting to obtain a mixed distribution model Fsmall (E) of the small-size dielectric; and an equation [1-Fsmall (E)] k = 1-Flarge (E) is constructed and solved, and a mixed distribution model Flarge (E) of the large-size dielectric is obtained. The calculation precision of the breakdown strength of the large-size dielectric can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of insulation technology, and more specifically, relates to a size effect prediction method for insulation dielectric breakdown and an application thereof. Background Art

[0002] The electrical strength of dielectric materials is an important indicator for measuring the reliability and life of dielectric insulation. For dielectrics, accurately estimating their breakdown strength and making corresponding insulation designs are the key to avoiding the danger of dielectric breakdown.

[0003] When estimating dielectric breakdown strength, the size effect of dielectric breakdown strength is an inevitable problem in engineering. The size effect is the phenomenon that the breakdown strength decreases with the increase of dielectric volume and area. In the breakdown strength test method recommended by relevant standards, the test object is generally a small-sized dielectric, that is, an area of ​​20cm 2 The following dielectrics, however, the size of dielectrics used in actual engineering may be 100 to 1000 times or even tens of thousands times the size of the test object. In this case, the increase in dielectric size will lead to a significant decrease in electrical strength, and the actual strength of the dielectric is also less than the breakdown strength of the test object. If the test results are used directly as a reference, there is a risk of insulation breakdown in engineering applications. Therefore, it is extremely important to fully consider the impact of the size effect in order to accurately predict the breakdown strength of large-size dielectrics.

[0004] The traditional size effect calculation method is based on the mathematical extrapolation method of a single distribution, which can infer the size effect of dielectric breakdown strength within a certain area. However, due to the complexity of the dielectric breakdown mechanism and the inconsistency of the breakdown causes, a single distribution cannot accurately describe the dielectric breakdown characteristics and the interaction between multiple breakdown causes, which leads to obvious errors or even failure of the traditional size effect calculation method in predicting the breakdown strength of large-sized dielectrics. Summary of the invention

[0005] In view of the defects and improvement needs of the prior art, the present invention provides a size effect prediction method for the breakdown of insulating dielectrics and its application, the purpose of which is to improve the calculation accuracy of the breakdown strength of large-size dielectrics.

[0006] To achieve the above object, according to one aspect of the present invention, a method for predicting the size effect of dielectric breakdown is provided, comprising:

[0007] Step S1: Select multiple large-sized dielectrics of different sizes, and obtain mixed distribution models of the large-sized dielectrics respectively; the mixed distribution model is used to describe the probability distribution of the breakdown strength of the dielectric, and the acquisition method includes:

[0008] Step S11: selecting a plurality of small-sized dielectrics of the same size, and performing breakdown tests respectively to determine the breakdown strength of each small-sized dielectric, and performing frequency analysis after obtaining a breakdown strength set to obtain the number of breakdown peaks and the breakdown strength range corresponding to each breakdown peak;

[0009] Step S12: Determine the distribution form used to describe the probability distribution of breakdown strength within each breakdown strength range, and fit to obtain a mixed distribution model F used to describe the probability distribution of the overall breakdown strength of the small-sized dielectric small (E);

[0010] Step S13: Construct the equation [1-F small (E)] k =1-F large (E) and solve to obtain the current large-size dielectric mixed distribution model F large (E); k is the ratio of the current large-size dielectric to the small-size dielectric;

[0011] Step S2: determining the overall breakdown strength of dielectrics of various sizes according to the mixed distribution model of dielectrics of various sizes, and calculating the size effect curve of the breakdown strength of the dielectric varying with size;

[0012] The area of ​​the large-sized dielectric is greater than a preset threshold, and the area of ​​the small-sized dielectric is not greater than the preset threshold.

[0013] Further, in step S2, the overall breakdown strength of the large-sized dielectric is the breakdown strength corresponding to 63.2% of the equivalent distribution cumulative probability of the mixed distribution model of the large-sized dielectric, or the overall breakdown strength of the large-sized dielectric is the mean of the mixed distribution model of the large-sized dielectric.

[0014] Further, in step S11, the number of the small-size dielectrics is not less than 30.

[0015] Further, in step S12, for any breakdown peak, a distribution form for describing the probability distribution of breakdown strength within its breakdown strength range is determined, including:

[0016] Searching for an entry containing the breakdown strength range from a pre-established query table, if the search is successful, determining the distribution form in the entry as the distribution form of the breakdown strength probability distribution within the breakdown strength range; if the search is unsuccessful, determining the distribution form of the breakdown strength probability distribution within the breakdown strength range as Weibull distribution;

[0017] Each entry in the query table records a known breakdown strength range and a corresponding distribution form of the breakdown strength probability distribution.

[0018] Further,

[0019]

[0020] Among them, F i (E) is the probability distribution of breakdown strength corresponding to the i-th breakdown peak, [E i ,E i+1 ) is the breakdown strength range corresponding to the i-th breakdown peak, 1≤i≤n, and n is the total number of breakdown peaks.

[0021] According to another aspect of the present invention, a method for estimating dielectric breakdown strength based on a multi-factor mixed distribution model is provided, comprising:

[0022] Substituting the size of the dielectric to be tested into the size effect curve of the breakdown strength of the dielectric changing with the size, the breakdown strength of the dielectric to be tested is obtained;

[0023] The size effect curve is estimated by the size effect prediction method for insulating dielectric breakdown provided by the present invention.

[0024] According to another aspect of the present invention, there is provided a size effect prediction system for dielectric breakdown of insulation, comprising: a mixed distribution model calculation module, a breakdown strength calculation module and a size effect curve calculation module;

[0025] Mixed distribution model calculation module, used to obtain the mixed distribution model of large-size dielectrics; the mixed distribution model is used to describe the probability distribution of the breakdown strength of the dielectric;

[0026] A breakdown strength calculation module is used to determine the overall breakdown strength of dielectrics of various sizes based on a mixed distribution model of dielectrics of various sizes;

[0027] The size effect curve calculation module is used to select large-sized dielectrics of different sizes, obtain the mixed distribution models of the large-sized dielectrics respectively using the mixed distribution model calculation module, determine the overall breakdown strength of the large-sized dielectrics using the breakdown strength calculation module, and calculate the size effect curve of the breakdown strength of the dielectric varying with size;

[0028] The mixed distribution model calculation module includes:

[0029] A breakdown test unit is used to select a plurality of small-sized dielectrics of the same size, and respectively conduct breakdown tests to determine the breakdown field strength of each small-sized dielectric, thereby obtaining a breakdown strength set;

[0030] A frequency analysis unit is used to perform frequency analysis on the breakdown strength set to obtain the number of breakdown peaks and the breakdown strength range corresponding to each breakdown peak;

[0031] The small size distribution calculation unit is used to determine the distribution form used to describe the probability distribution of breakdown strength within each breakdown strength range, and to fit the mixed distribution model F used to describe the probability distribution of the overall breakdown strength of small size dielectrics. small (E);

[0032] and a large size distribution calculation unit to construct the equation [1-F small (E)] k =1-F large (E) and solve to obtain the current large-size dielectric mixed distribution model F large (E); k is the ratio of the current large-size dielectric to the small-size dielectric;

[0033] The area of ​​the large-sized dielectric is greater than a preset threshold, and the area of ​​the small-sized dielectric is not greater than the preset threshold.

[0034] According to another aspect of the present invention, a computer program product is provided, comprising a computer program; when the computer program is executed by a processor, the above-mentioned dielectric breakdown strength estimation method based on the multi-factor mixed distribution model provided by the present invention is implemented.

[0035] According to another aspect of the present invention, a computer-readable storage medium is provided, comprising a stored computer program; when the computer program is executed by a processor, the above-mentioned dielectric breakdown strength estimation method based on the multi-factor mixed distribution model provided by the present invention is implemented.

[0036] According to yet another aspect of the present invention, there is provided an electronic device comprising a computer-readable storage medium and a processor;

[0037] The computer readable storage medium is used to store the computer program;

[0038] The processor is used to read the computer program stored in the computer-readable storage medium to implement the above-mentioned dielectric breakdown strength estimation method based on the multi-factor mixed distribution model provided by the present invention.

[0039] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0040] (1) The present invention realizes attribution analysis by performing frequency analysis on the test data of the breakdown strength of small-sized dielectrics, thereby discovering a variety of breakdown mechanisms and corresponding distribution forms, so that when constructing the probability distribution of the breakdown strength of large-sized dielectrics, it is possible to take into account the changing laws of various breakdown mechanisms or causes, and finally accurately estimate the relationship between the breakdown strength of large-sized dielectrics and the size, providing strong support for the accurate breakdown strength of large-sized dielectrics.

[0041] (2) After estimating the mixed distribution model corresponding to each large-sized dielectric, the present invention uses the breakdown strength corresponding to the equivalent distribution cumulative probability of 63.2% of the mixed distribution model as the overall breakdown strength of the large-sized dielectric, or uses the mean of the mixed distribution model as the overall breakdown strength of the large-sized dielectric, thereby accurately characterizing the overall breakdown strength of the large-sized dielectric.

[0042] (3) Based on a query table that records known breakdown strength ranges and corresponding breakdown strength probability distribution forms, the present invention searches for the corresponding distribution form in the query table based on the breakdown strength range corresponding to each breakdown peak, and when it cannot be determined by looking up the table, determines that the corresponding distribution form is a general Weibull distribution, thereby being able to accurately and quickly determine the distribution form of the breakdown strength probability distribution under the breakdown mechanism corresponding to each breakdown peak. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A flow chart of a method for predicting the size effect of dielectric breakdown of an insulating material provided by an embodiment of the present invention;

[0044] Figure 2 A schematic diagram of a hybrid distribution provided by an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the size effect calculation results provided for this hairstyle embodiment. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the accompanying drawings are used to distinguish similar objects but not necessarily to describe a specific order or sequence.

[0048] In order to solve the problem that the existing dielectric size effect estimation method has obvious errors or even fails when predicting the breakdown strength of large-sized dielectrics, the present invention provides a size effect prediction method for insulating dielectric breakdown and its application. The overall concept is to analyze various breakdown causes of dielectrics based on statistical methods, and establish a corresponding hybrid model to accurately describe the dielectric breakdown characteristics and the action rules of various breakdown causes, thereby improving the accuracy of size effect estimation, and further improving the estimation accuracy of large-sized dielectric breakdown strength.

[0049] The following are examples.

[0050] Embodiment 1:

[0051] A size effect prediction method for dielectric breakdown of an insulating material, comprising:

[0052] Step S1: selecting a plurality of large-sized dielectrics of different sizes, and obtaining mixed distribution models of the large-sized dielectrics respectively; the mixed distribution model is used to describe the probability distribution of the breakdown strength of the dielectric;

[0053] Step S2: determining the overall breakdown strength of dielectrics of various sizes according to the mixed distribution model of dielectrics of various sizes, and calculating the size effect curve of the breakdown strength of the dielectric varying with size.

[0054] The specific implementation of each step is explained in detail below.

[0055] In step S1 of this embodiment, when constructing a mixed distribution model for describing the probability distribution of the breakdown strength of a large-sized dielectric, the influence of multiple breakdown causes on the size effect is fully considered. Figure 1 As shown, the method for obtaining the mixed distribution model specifically includes steps S11 to S13, and each step is specifically as follows:

[0056] Step S11: selecting a plurality of small-sized dielectrics of the same size, and performing breakdown tests respectively to determine the breakdown strength of each small-sized dielectric, and performing frequency analysis after obtaining a breakdown strength set to obtain the number of breakdown peaks and the breakdown strength range corresponding to each breakdown peak;

[0057] In this embodiment, the area of ​​the large-size dielectric is greater than the preset threshold, and the area of ​​the small-size dielectric is not greater than the preset threshold. Referring to the corresponding standards in the industry, the preset threshold is specifically set to 20 cm 2 When conducting breakdown tests on small-sized dielectrics, the test can be carried out in accordance with national standards or IEC standards. The resulting breakdown strength set is represented by {E bn It is easy to understand that the environmental conditions of small-size dielectric experiments should be close to the working conditions or application conditions to reduce the interference of environmental conditions on the size effect calculation.

[0058] In step S11 of this embodiment, the breakdown strength set {E bn}In the breakdown peaks obtained by frequency analysis and the breakdown strength ranges corresponding to each breakdown peak, each breakdown peak corresponds to a breakdown mechanism. Although the breakdown mechanism cannot be determined, the breakdown strength range corresponding to the breakdown peak reflects the range of the breakdown strength probability distribution under the action of the corresponding breakdown mechanism. Therefore, after obtaining the distribution form within the breakdown strength range, the distribution form of the breakdown strength probability distribution under the action of the corresponding breakdown mechanism can be obtained.

[0059] In order to reduce the interference of randomness on the size effect calculation and fully explore various breakdown mechanisms, in step S11 of this embodiment, the number of small-size dielectrics selected is not less than 30.

[0060] During the frequency analysis process, the number of breakdown peaks analyzed is not less than 2.

[0061] Step S12: Determine the distribution form used to describe the probability distribution of breakdown strength within each breakdown strength range, and fit to obtain a mixed distribution model F used to describe the probability distribution of the overall breakdown strength of the small-sized dielectric small (E).

[0062] The distribution forms that can be used to describe the probability distribution of dielectric breakdown strength include but are not limited to Weibull distribution, normal distribution, Gumbel distribution, etc. Based on existing research results or research methods, the distribution forms of the probability distribution of breakdown strength within different breakdown strength ranges can be obtained.

[0063] In order to obtain the distribution form of the breakdown strength probability distribution under the breakdown mechanism corresponding to each breakdown peak, this embodiment will establish a query table in advance based on prior knowledge or through existing research methods. Each item in the query table records the known breakdown strength range and the corresponding distribution form of the breakdown strength probability distribution.

[0064] In practical applications, some unknown breakdown mechanisms may occur, and the corresponding distribution form may not be recorded in the established query table. In this case, the general Weibull distribution can be used to describe the corresponding breakdown strength probability distribution. Based on this, in step S12 of this embodiment, for any breakdown peak, the distribution form used to describe the breakdown strength probability distribution within its breakdown strength range is determined, including:

[0065] A table entry containing the breakdown strength range is searched from a pre-established query table. If the search is successful, the distribution form in the table entry is determined as the distribution form of the breakdown strength probability distribution within the breakdown strength range; if the search is unsuccessful, the distribution form of the breakdown strength probability distribution within the breakdown strength range is determined as Weibull distribution.

[0066] The distribution corresponding to each breakdown peak can be regarded as a sub-distribution. The number of sub-distributions of the dielectric mixed distribution is determined according to the dielectric breakdown mechanism and the number of breakdown peaks n in the data, and is not less than 2. The distribution forms of multiple sub-distributions may be the same or different.

[0067] After sorting the breakdown peaks in order from large to small, the breakdown strength range corresponding to each breakdown peak can be expressed as [E i ,E i+1) is the breakdown strength range corresponding to the i-th breakdown peak, 1≤i≤n, and the corresponding breakdown strength probability distribution can be expressed as F i (E).

[0068] The joint action of multiple breakdown mechanisms is specifically as follows: within the range of [E1, E2), only the first breakdown mechanism exists; within the range of [E2, E3), the first and second breakdown mechanisms exist at the same time; within the range of [E3, E4), the first, second and third breakdown mechanisms exist at the same time; and so on.

[0069] Therefore, after determining the mathematical form of the mixed distribution sub-distribution, the mass mixed distribution model F of small-size dielectric small (E) is:

[0070]

[0071] The electrical weakness in the dielectric complies with the relationship of increasing linearly with the size. The volume of the small-sized dielectric sample is recorded as V1, and the volume of the current large-sized dielectric to be calculated is recorded as V2, and V2 / V1=k. According to breakdown statistics, the probability that a large-sized dielectric does not break down is equivalent to the probability that k small-sized dielectrics do not break down. Therefore, in order to obtain a mixed distribution model of large-sized dielectrics, step S13 of this embodiment is: construct the equation [1-F small (E)] k =1-F large (E) and solve to obtain the current large-size dielectric mixed distribution model F large (E).

[0072] It is easy to understand that for the above equation [1-F small (E)] k =1-F large (E), whose constraints include the minimum breakdown strength and the maximum breakdown strength constraints, and the parameters required to be solved include F small (E) The distribution parameters of each sub-division; Optionally, in this embodiment, when solving [1-F small (E)] k =1-F large (E), after determining the constraints and the number of unknown parameters, select the corresponding number of special electric field strength points to numerically solve the equation. The selected special electric field strength points are located within the breakdown strength range corresponding to the sub-distribution to reduce the difficulty of calculation.

[0073] Based on the above steps S11 to S13, this embodiment can obtain the mixed distribution model corresponding to each large size of dielectric.

[0074] In step S2 of this embodiment, the overall breakdown strength of the large-sized dielectric determined based on the mixed distribution model of the large-sized dielectric is the breakdown strength corresponding to the equivalent distribution cumulative probability of the mixed distribution model of the large-sized dielectric being 63.2%, or the mean of the mixed distribution model of the large-sized dielectric. The breakdown strength thus obtained can more accurately characterize the breakdown strength parameters of the dielectric as a whole.

[0075] Since the sizes of dielectrics of various sizes are known, after obtaining the overall breakdown strength of dielectrics of various sizes, the size effect curve of the breakdown strength of the dielectric varying with size can be calculated.

[0076] The size effect curve finally calculated in this embodiment specifically describes the relationship between the breakdown strength of the dielectric and the change in volume. The relevant estimation method can also calculate the change in breakdown strength caused by the change in dielectric area, but the dielectric thickness should be kept consistent.

[0077] In general, the size effect estimation method proposed in this embodiment realizes attribution analysis by performing frequency analysis on the test data of the breakdown strength of small-sized dielectrics, thereby discovering a variety of breakdown mechanisms and corresponding distribution forms, so that when constructing the breakdown strength probability distribution of large-sized dielectrics, it is possible to take into account the changing laws of various breakdown mechanisms or causal effects, and ultimately accurately estimate the relationship between the breakdown strength of large-sized dielectrics and their size.

[0078] Embodiment 2:

[0079] A dielectric breakdown strength estimation method based on a multi-factor mixed distribution model, comprising:

[0080] Substituting the size of the dielectric to be tested into the size effect curve of the breakdown strength of the dielectric changing with the size, the breakdown strength of the dielectric to be tested is obtained;

[0081] The size effect curve is estimated by the size effect prediction method for insulating dielectric breakdown in the above-mentioned embodiment 1.

[0082] Embodiment 3:

[0083] A size effect prediction system for dielectric breakdown of insulation, comprising: a mixed distribution model calculation module, a breakdown strength calculation module and a size effect curve calculation module;

[0084] Mixed distribution model calculation module, used to obtain the mixed distribution model of large-size dielectrics; the mixed distribution model is used to describe the probability distribution of the breakdown strength of the dielectric;

[0085] A breakdown strength calculation module is used to determine the overall breakdown strength of dielectrics of various sizes based on a mixed distribution model of dielectrics of various sizes;

[0086] The size effect curve calculation module is used to select large-sized dielectrics of different sizes, obtain the mixed distribution models of the large-sized dielectrics respectively using the mixed distribution model calculation module, determine the overall breakdown strength of the large-sized dielectrics using the breakdown strength calculation module, and calculate the size effect curve of the breakdown strength of the dielectric varying with size;

[0087] The mixed distribution model calculation module includes:

[0088] A breakdown test unit is used to select a plurality of small-sized dielectrics of the same size, and respectively conduct breakdown tests to determine the breakdown field strength of each small-sized dielectric, thereby obtaining a breakdown strength set;

[0089] A frequency analysis unit is used to perform frequency analysis on the breakdown strength set to obtain the number of breakdown peaks and the breakdown strength range corresponding to each breakdown peak;

[0090] The small size distribution calculation unit is used to determine the distribution form used to describe the probability distribution of breakdown strength within each breakdown strength range, and to fit the mixed distribution model F used to describe the probability distribution of the overall breakdown strength of small size dielectrics. small (E);

[0091] and a large size distribution calculation unit to construct the equation [1-F small (E)] k =1-F large (E) and solve to obtain the current large-size dielectric mixed distribution model F large (E); k is the ratio of the current large-size dielectric to the small-size dielectric;

[0092] The area of ​​the large-sized dielectric is greater than a preset threshold, and the area of ​​the small-sized dielectric is not greater than the preset threshold.

[0093] In this embodiment, the specific implementation of each module can refer to the description in the above embodiment 1 and will not be repeated here.

[0094] Embodiment 4:

[0095] A computer program product includes a computer program; when the computer program is executed by a processor, the method for estimating dielectric breakdown strength based on a multi-factor mixed distribution model provided in the above-mentioned embodiment 1 is implemented.

[0096] Embodiment 5:

[0097] A computer-readable storage medium includes a stored computer program; when the computer program is executed by a processor, the dielectric breakdown strength estimation method based on the multi-factor mixed distribution model provided in the above-mentioned embodiment 1 is implemented.

[0098] Embodiment 6:

[0099] An electronic device comprising a computer-readable storage medium and a processor;

[0100] The computer readable storage medium is used to store the computer program;

[0101] The processor is used to read the computer program stored in the computer-readable storage medium to implement the dielectric breakdown strength estimation method based on the multi-factor mixed distribution model in the above-mentioned embodiment 1.

[0102] The beneficial effects that can be achieved by the present invention are further analyzed and explained below in conjunction with specific estimation examples.

[0103] The thickness used is d and the area is 20cm 2 Polypropylene film was used as the sample. According to the electrode method recommended by the national standard GB T 13542.2-2021 Electrical insulation film, the breakdown strength of these samples was measured, and the number of measured samples was 80. The breakdown strength data of the measured samples were subjected to frequency analysis, and three breakdown peaks and the breakdown strength ranges corresponding to each breakdown peak were obtained. The three-parameter Weibull mixed distribution containing three sub-distributions was used to fit the experimental data, and the corresponding mixed distribution parameters were obtained, such as Figure 2 As shown. Using the size effect calculation method, we get 1000cm 2 The mixed distribution parameters change within the range. The equivalent single distribution is deduced through the mixed distribution parameters, and the breakdown field strength E corresponding to the cumulative probability of the equivalent single distribution is 63.2% is selected. α As a parameter to characterize the overall breakdown strength, the final calculated curve is as follows Figure 3 shown.

[0104] To verify the accuracy of the size effect calculation method, the area of ​​48cm was added under the same conditions. 2 The E a The experimental value is 622.6V / μm, which is 0.5% different from the actual calculated value of 626.1V / μm. This indicates that the size effect curve estimated by the present invention can accurately estimate the breakdown strength of large-size dielectrics. It should also be noted that when the size effect is estimated using the traditional single distribution estimation method, the final estimated dielectric breakdown strength has a deviation of 5% to 10% compared to the actual calculated result. By comparison, the present invention can effectively improve the accuracy of dielectric breakdown strength estimation.

[0105] It will be easily understood by those skilled in the art that 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 protection scope of the present invention.

Claims

1. A method for predicting the size effect of dielectric breakdown, characterized in that: include: Step S1: selecting a plurality of large-sized dielectrics of different sizes, and obtaining mixed distribution models of the large-sized dielectrics respectively; The mixed distribution model is used to describe the probability distribution of the breakdown strength of the dielectric, and the acquisition method includes: Step S11: selecting a plurality of small-sized dielectrics of the same size, and performing breakdown tests respectively to determine the breakdown strength of each small-sized dielectric, and performing frequency analysis after obtaining a breakdown strength set to obtain the number of breakdown peaks and the breakdown strength range corresponding to each breakdown peak; Step S12: Determine the distribution form used to describe the probability distribution of breakdown strength within each breakdown strength range, and fit to obtain a mixed distribution model F used to describe the probability distribution of the overall breakdown strength of the small-sized dielectric small (E); Step S13: Construct the equation [1-F small (E)] k =1-F large (E) and solve to obtain the current large-size dielectric mixed distribution model F large (E); k is the ratio of the current large-size dielectric to the small-size dielectric; Step S2: determining the overall breakdown strength of dielectrics of various sizes according to the mixed distribution model of dielectrics of various sizes, and calculating the size effect curve of the breakdown strength of the dielectric varying with size; The area of ​​the large-sized dielectric is greater than a preset threshold, and the area of ​​the small-sized dielectric is not greater than the preset threshold.

2. The size effect prediction method for dielectric breakdown of an insulating material according to claim 1, characterized in that: In step S2, the overall breakdown strength of the large-sized dielectric is the breakdown strength corresponding to 63.2% of the equivalent distribution cumulative probability of the mixed distribution model of the large-sized dielectric, or the overall breakdown strength of the large-sized dielectric is the mean of the mixed distribution model of the large-sized dielectric.

3. The size effect prediction method for insulating dielectric breakdown according to claim 1 or 2, characterized in that: In the step S11, the number of the small-size dielectrics is not less than 30.

4. The size effect prediction method for dielectric breakdown of an insulating material according to claim 3, characterized in that: In the step S12, for any breakdown peak, a distribution form for describing the probability distribution of breakdown strength within its breakdown strength range is determined, including: Searching for an entry containing the breakdown strength range from a pre-established query table, if the search is successful, determining the distribution form in the entry as the distribution form of the breakdown strength probability distribution within the breakdown strength range; if the search is unsuccessful, determining the distribution form of the breakdown strength probability distribution within the breakdown strength range as Weibull distribution; Each entry in the query table records a known breakdown strength range and a corresponding distribution form of the breakdown strength probability distribution.

5. The size effect prediction method for dielectric breakdown of an insulating material according to claim 1 or 2, characterized in that: Among them, F i (E) is the probability distribution of breakdown strength corresponding to the i-th breakdown peak, [E i ,E i+1 ) is the breakdown strength range corresponding to the i-th breakdown peak, 1≤i≤n, and n is the total number of breakdown peaks.

6. A dielectric breakdown strength estimation method based on a multi-factor mixed distribution model, characterized in that: include: Substituting the size of the dielectric to be measured into the size effect curve of the breakdown strength of the dielectric varying with the size, to obtain the breakdown strength of the dielectric to be measured; Wherein, the size effect curve is estimated by the size effect prediction method for insulating dielectric breakdown according to any one of claims 1 to 5.

7. A size effect prediction system for dielectric breakdown of insulation, characterized in that: include: Mixed distribution model calculation module, breakdown strength calculation module and size effect curve calculation module; The mixed distribution model calculation module is used to obtain a mixed distribution model of a large-size dielectric; the mixed distribution model is used to describe the probability distribution of the breakdown strength of the dielectric; The breakdown strength calculation module is used to determine the overall breakdown strength of dielectrics of various sizes according to the mixed distribution model of dielectrics of various sizes; The size effect curve calculation module is used to select large-sized dielectrics of different sizes, use the mixed distribution model calculation module to obtain the mixed distribution models of the large-sized dielectrics respectively, use the breakdown strength calculation module to determine the overall breakdown strength of the large-sized dielectrics, and calculate the size effect curve of the breakdown strength of the dielectric varying with size; The mixed distribution model calculation module includes: A breakdown test unit is used to select a plurality of small-sized dielectrics of the same size, and respectively conduct breakdown tests to determine the breakdown field strength of each small-sized dielectric, thereby obtaining a breakdown strength set; A frequency analysis unit is used to perform frequency analysis on the breakdown strength set to obtain the number of breakdown peaks and the breakdown strength range corresponding to each breakdown peak; The small size distribution calculation unit is used to determine the distribution form used to describe the probability distribution of breakdown strength within each breakdown strength range, and to fit the mixed distribution model F used to describe the probability distribution of the overall breakdown strength of small size dielectrics. small (E); and a large size distribution calculation unit to construct the equation [1-F small (E)] k =1-F large (E) and solve to obtain the current large-size dielectric mixed distribution model F large (E); k is the ratio of the current large-size dielectric to the small-size dielectric; The area of ​​the large-sized dielectric is greater than a preset threshold, and the area of ​​the small-sized dielectric is not greater than the preset threshold.

8. A computer program product, characterized in that It includes a computer program; when the computer program is executed by a processor, it implements the dielectric breakdown strength estimation method based on a multi-factor mixed distribution model as described in claim 6.

9. A computer-readable storage medium, characterized in that: It comprises a stored computer program; when the computer program is executed by a processor, it implements the dielectric breakdown strength estimation method based on a multi-factor mixed distribution model as described in claim 6.

10. An electronic device, characterized in that: comprising a computer readable storage medium and a processor; The computer readable storage medium is used to store a computer program; The processor is used to read the computer program stored in the computer-readable storage medium to implement the dielectric breakdown strength estimation method based on the multi-factor mixed distribution model described in claim 6.

Images