Gap breakdown risk assessment method, system, device and medium

Abstract

The invention discloses a gap breakdown risk assessment method, system and device and a medium, and belongs to the field of electric power systems.The method comprises the steps that obtained particle size parameters and particle size proportions of all particles are input into a forest fire gap breakdown risk assessment model, and a risk assessment result is output, the forest fire gap breakdown risk assessment model is obtained by training according to a target gap breakdown voltage calculation formula and historical operation and maintenance data, the target gap breakdown voltage calculation formula is determined according to particle sample data, breakdown voltage data and correction coefficients of different gap areas, and the particle sample data comprises multiple groups of particle samples; the particle size parameters and the particle size proportions of the samples are different, the breakdown voltage data comprises a plurality of breakdown voltages, each voltage is determined according to each group of particle samples, and the correction coefficient of each gap region is determined according to the first gap breakdown voltage gradient and the second gap breakdown voltage gradient. Accurate assessment of the breakdown risk of the overhead transmission line can be realized.

Description

Technical Field

[0001] The present invention relates to the field of power systems, and in particular to a gap breakdown risk assessment method, system, equipment and medium. Background Art

[0002] High-voltage transmission lines efficiently transmit energy in the form of electricity. However, these lines often traverse mountainous areas with dense vegetation. In the event of a forest fire, the burning vegetation rapidly raises the ambient temperature and produces large amounts of smoke particles. These smoke particles can affect the insulation performance of transmission lines and alter the gap breakdown characteristics of overhead transmission lines. Consequently, smoke particles increase the risk of insulation failure in transmission lines. Once a line gap breakdown occurs, it can cause faults such as tripping, reducing the stability and safety of the power system.

[0003] However, the existing gap breakdown risk assessment model does not take into account the impact of smoke particles with different particle size distributions on the gap breakdown characteristics of different partitions of overhead transmission lines. Therefore, under wildfire conditions, the accuracy of the gap breakdown risk assessment of overhead transmission lines is low. Summary of the Invention

[0004] The present invention provides a gap breakdown risk assessment method, system, device and medium, which can solve the problem of low accuracy in breakdown risk assessment and realize accurate assessment of breakdown risk of overhead transmission lines in power systems.

[0005] The present invention provides a gap breakdown risk assessment method, comprising:

[0006] Obtaining a gap area of ​​an overhead transmission line to be evaluated, a plurality of particle size parameters under wildfire conditions, and a particle size ratio corresponding to each of the particle size parameters;

[0007] Each of the particle size parameters and each of the particle size ratios is input into a wildfire gap breakdown risk assessment model, and a risk assessment result is output, wherein the wildfire gap breakdown risk assessment model is trained based on a target gap breakdown voltage calculation formula and historical operation and maintenance data, the target gap breakdown voltage calculation formula is determined based on particle sample data, breakdown voltage data, and correction coefficients for different gap areas, the particle sample data includes multiple groups of particle samples, and the particle size parameters and particle size ratios in each group of the particle samples are different, the breakdown voltage data includes multiple breakdown voltages, each of the breakdown voltages is determined based on each group of the particle samples, and the correction coefficient of each gap area is determined based on a first gap breakdown voltage gradient and a second gap breakdown voltage gradient, the first gap breakdown voltage gradient is the gap breakdown voltage gradient in the initial state, and the second gap breakdown voltage gradient is the gap breakdown voltage gradient in the particle state.

[0008] An embodiment of the present invention determines a target gap breakdown voltage calculation formula based on particle sample data including multiple groups of particle samples, breakdown voltage data including multiple breakdown voltages, and correction coefficients for different gap areas. By considering the impact of smoke particles with different particle size distributions on the gap breakdown characteristics of different partitions of the overhead transmission line, the gap breakdown voltage of the overhead transmission line is corrected using the correction coefficient, thereby obtaining a more accurate gap breakdown voltage. Furthermore, a wildfire gap breakdown risk assessment model obtained by training based on historical operation and maintenance data and the target gap breakdown voltage calculation formula is used to evaluate multiple particle size parameters and particle size ratios obtained under wildfire conditions, thereby obtaining a more accurate gap breakdown risk assessment result.

[0009] Furthermore, the target gap breakdown voltage calculation formula is determined based on the particle sample data, the breakdown voltage data, and the correction coefficients of different gap regions. The correction coefficient of each gap region is determined based on the first gap breakdown voltage gradient and the second gap breakdown voltage gradient, specifically:

[0010] For each group of particle samples, determining an initial correction coefficient of each gap region corresponding to each group of particle samples according to a first gap breakdown voltage gradient of each gap region and a second gap breakdown voltage gradient of each gap region;

[0011] Based on the particle sample data and the initial correction coefficients of the gap regions corresponding to each group of the particle samples, a multivariate nonlinear regression fitting is performed to obtain a target correction coefficient corresponding to each gap region;

[0012] The target gap breakdown voltage calculation formula is determined according to the target correction coefficient corresponding to each gap region and the first gap breakdown voltage gradient corresponding to each gap region.

[0013] In this way, the initial correction coefficient is determined by the first gap breakdown voltage gradient and the second gap breakdown voltage gradient of each gap area, and through multivariate nonlinear regression fitting, the complex relationship between the particle sample data and the initial correction coefficient is comprehensively considered to obtain a more accurate target correction coefficient. The target correction coefficient is used to determine the target gap breakdown voltage calculation formula, which can enable the formula to better reflect the gap breakdown characteristics in different gap areas and different particle size distributions, thereby improving the accuracy of risk assessment.

[0014] Furthermore, the gap region includes a flame continuous region, a flame discontinuous region, and a smoke region, and the initial correction coefficient includes a first correction coefficient corresponding to the flame discontinuous region and a second correction coefficient corresponding to the smoke region; the initial correction coefficient of each gap region corresponding to each group of the particle samples is determined based on the first gap breakdown voltage gradient and the second gap breakdown voltage gradient of each gap region, specifically:

[0015] For the flame continuous zone, setting a first gap breakdown voltage gradient of the flame continuous zone in an initial state to be equal to a second gap breakdown voltage gradient in a particle state;

[0016] For each group of particle samples, respectively obtaining the lengths of the flame continuous area, the flame discontinuous area, and the smoke area;

[0017] Based on the initial gap breakdown voltage calculation formula, and based on each breakdown voltage corresponding to each group of particle samples and the region length of each gap region, respectively determining the second gap breakdown voltage gradient of the flame discontinuous region and the smoke region;

[0018] A first correction coefficient corresponding to the flame discontinuous zone is obtained based on the first gap breakdown voltage gradient corresponding to the flame discontinuous zone and the second gap breakdown voltage gradient corresponding to the flame discontinuous zone; and a second correction coefficient corresponding to the smoke zone is obtained based on the first gap breakdown voltage gradient corresponding to the smoke zone and the second gap breakdown voltage gradient corresponding to the smoke zone.

[0019] Because the flame body has a higher electrical conductivity and temperature, smoke particles have a smaller impact on the insulation degradation of the continuous and discontinuous flame zones, while their impact is greater in the smoke zone. Therefore, it can be assumed that particles primarily affect the gap breakdown characteristics of the smoke and discontinuous flame zones. Their effect on the flame zone, where resistance can reach megaohms, is minimal and can be ignored. Based on this, by setting the first gap breakdown voltage gradient of the continuous flame zone in its initial state equal to the second gap breakdown voltage gradient of the particle state, the computational complexity can be reduced. By obtaining the length of each gap region and combining it with the initial gap breakdown voltage calculation formula and breakdown voltage data, the second gap breakdown voltage gradient of the discontinuous flame zone and the smoke zone can be determined separately. Based on the first and second gap breakdown voltage gradients of each gap region, initial correction coefficients are derived for the discontinuous flame zone and the smoke zone, respectively. This process fully accounts for the differences in the characteristics of different gap regions, enabling the correction coefficients to more accurately reflect the impact of each gap region on gap breakdown.

[0020] Furthermore, the wildfire gap breakdown risk assessment model is trained based on the target gap breakdown voltage calculation formula and historical operation and maintenance data, specifically:

[0021] The historical operation and maintenance data is input into the wildfire gap breakdown risk assessment model, so that the wildfire gap breakdown risk assessment model calculates the historical particle size data in the historical operation and maintenance data according to the target gap breakdown voltage calculation formula to obtain the gap breakdown voltage, and obtains a voltage comparison result by comparing the voltage peak in the historical operation and maintenance data with the gap breakdown voltage. The wildfire gap breakdown risk assessment model is trained according to the voltage comparison result and the preset risk classification standard.

[0022] In this way, by training the model with historical operation and maintenance data, the model can better adapt to the actual situation and improve the accuracy of risk assessment.

[0023] Furthermore, the preset risk classification standards are specifically:

[0024] When the voltage comparison result is greater than a first threshold, the risk assessment result is low risk;

[0025] When the voltage comparison result is less than or equal to the first threshold and greater than the second threshold, the risk assessment result is medium risk;

[0026] When the voltage comparison result is less than or equal to the second threshold and greater than a third threshold, the risk assessment result is high risk;

[0027] When the voltage comparison result is less than or equal to a third threshold, the risk assessment result is an extremely high risk; wherein the first threshold, the second threshold, and the third threshold are determined according to the voltage peak value and decrease in sequence.

[0028] In this way, by setting clear preset risk classification standards and comparing the voltage comparison results with different thresholds, the risk assessment results can be quantified into four levels: low risk, medium risk, high risk and extremely high risk, making the risk assessment results more intuitive and more operational.

[0029] Furthermore, the target gap breakdown voltage calculation formula is specifically:

[0030] U=E f1 *H1+E fs1 *K′1*H fs +E s1 *K′2*H s ;

[0031] Where U is the gap breakdown voltage, in kV; E f1 、E fs1 and E s1 are the first gap breakdown voltage gradients of the flame continuous zone, flame discontinuous zone and smoke zone, respectively, in kV; H1, H fs and H swhere are the lengths of the flame continuous zone, flame discontinuous zone and smoke zone, respectively, in meters; K′1 and K′2 are the target correction coefficients of the flame discontinuous zone and smoke zone for the gap breakdown voltage, respectively.

[0032] This gives the specific form of the target gap breakdown voltage calculation formula, clarifies the relationship between various parameters, and provides a clear calculation method for accurately calculating the gap breakdown voltage.

[0033] Furthermore, the calculation formulas of the first correction coefficient and the second correction coefficient are specifically:

[0034]

[0035] Wherein, K1 is the first correction coefficient corresponding to the flame discontinuous area, and K2 is the second correction coefficient corresponding to the smoke area;

[0036] And, the formula for multivariate nonlinear regression fitting is specifically,

[0037]

[0038] Among them, D1, D2, and D3 are the corresponding particle sizes when the cumulative distribution proportion in each group of the particle samples reaches the first threshold, the second threshold, and the third threshold, and the first threshold, the second threshold, and the third threshold increase successively; a1, a2, and a3 are the proportions of the corresponding particle sizes; b1, b2, b3, c1, c2, and c3 are fitting coefficients.

[0039] In this way, by further clarifying the calculation formulas of the first correction coefficient and the second correction coefficient, as well as the specific formula of the multivariate nonlinear regression fitting, the calculation process of the correction coefficient is made clearer and more specific, and the accuracy of the target gap breakdown voltage calculation formula is improved.

[0040] Another embodiment of the present invention further provides a gap breakdown risk assessment system, comprising: an acquisition module and an assessment module;

[0041] The acquisition module is configured to acquire a gap area of ​​the overhead transmission line to be evaluated, a plurality of particle size parameters under wildfire conditions, and a particle size ratio corresponding to each of the particle size parameters;

[0042] The evaluation module is used to input each of the particle size parameters and each of the particle size ratios into a wildfire gap breakdown risk assessment model and output a risk assessment result, wherein the wildfire gap breakdown risk assessment model is trained based on a target gap breakdown voltage calculation formula and historical operation and maintenance data, the target gap breakdown voltage calculation formula is determined based on particle sample data, breakdown voltage data, and correction coefficients of different gap areas, the particle sample data includes multiple groups of particle samples, and the particle size parameters and particle size ratios in each group of the particle samples are different, the breakdown voltage data includes multiple breakdown voltages, each of the breakdown voltages is determined based on each group of the particle samples, and the correction coefficient of each gap area is determined based on a first gap breakdown voltage gradient and a second gap breakdown voltage gradient, the first gap breakdown voltage gradient is the gap breakdown voltage gradient in the initial state, and the second gap breakdown voltage gradient is the gap breakdown voltage gradient in the particle state.

[0043] An embodiment of the present invention determines a target gap breakdown voltage calculation formula based on particle sample data including multiple groups of particle samples, breakdown voltage data including multiple breakdown voltages, and correction coefficients for different gap areas. By considering the impact of smoke particles with different particle size distributions on the gap breakdown characteristics of different partitions of the overhead transmission line, the gap breakdown voltage of the overhead transmission line is corrected using the correction coefficient, thereby obtaining a more accurate gap breakdown voltage. Furthermore, a wildfire gap breakdown risk assessment model obtained by training based on historical operation and maintenance data and the target gap breakdown voltage calculation formula is used to evaluate multiple particle size parameters and particle size ratios obtained under wildfire conditions, thereby obtaining a more accurate gap breakdown risk assessment result.

[0044] Another embodiment of the present invention further provides a terminal device, comprising: a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the steps of the gap breakdown risk assessment method of the present invention are implemented.

[0045] Another embodiment of the present invention further provides a computer-readable storage medium item, comprising: a stored computer program, which controls the device where the computer-readable storage medium is located to execute the steps of the gap breakdown risk assessment method of the present invention when the computer program is executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0047] Figure 1It is a flow chart of an embodiment of a gap breakdown risk assessment method;

[0048] Figure 2 Schematic diagram of a smoke particle size gap breakdown characteristic simulation test platform provided by an embodiment of the present invention;

[0049] Figure 3 It is a structural diagram of an embodiment of a gap breakdown risk assessment system. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0053] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0056] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0057] See also Figure 1 To solve the problem of low accuracy in gap breakdown risk assessment in the prior art, an embodiment of the present invention provides a gap breakdown risk assessment method, including steps S101 and S102, as follows:

[0058] Step S101: Obtain a gap area of ​​an overhead transmission line to be evaluated, a plurality of particle size parameters under wildfire conditions, and a particle size ratio corresponding to each of the particle size parameters.

[0059] In this embodiment, in an actual environment, if there is a wildfire at the location of the overhead transmission line to be evaluated, particle data sampling can be performed on the gap area of ​​the overhead transmission line to be evaluated using drone remote sensing technology to obtain the particle size parameters of the gap area and the particle size ratios corresponding to each of the particle size parameters.

[0060] Step S102: input each of the particle size parameters and each of the particle size ratios into a wildfire gap breakdown risk assessment model, and output a risk assessment result, wherein the wildfire gap breakdown risk assessment model is trained based on a target gap breakdown voltage calculation formula and historical operation and maintenance data, the target gap breakdown voltage calculation formula is determined based on particle sample data, breakdown voltage data, and correction coefficients for different gap areas, the particle sample data includes multiple groups of particle samples, and the particle size parameters and particle size ratios in each group of the particle samples are different, the breakdown voltage data includes multiple breakdown voltages, each of the breakdown voltages is determined based on each group of the particle samples, and the correction coefficient of each gap area is determined based on a first gap breakdown voltage gradient and a second gap breakdown voltage gradient, the first gap breakdown voltage gradient is the gap breakdown voltage gradient in the initial state, and the second gap breakdown voltage gradient is the gap breakdown voltage gradient in the particle state.

[0061] In this embodiment, the temperature of different gap areas can be identified by infrared devices or thermocouples, and the temperature characteristics can be identified to divide the gap areas into flame areas and smoke areas. Furthermore, the flame areas can be divided into flame continuous areas and flame discontinuous areas at a ratio of 3 to 1. The area lengths of different gap areas are determined based on the division results, and each of the particle size parameters, each of the particle size ratios, and each area length is input into the wildfire gap breakdown risk assessment model to output the risk assessment results. The wildfire gap breakdown risk assessment model is obtained by determining an initial risk assessment model based on a target gap breakdown voltage calculation formula, and training the initial risk assessment model based on historical operation and maintenance data. The target gap breakdown voltage calculation formula can be determined based on test data collected in a wildfire simulation test. For example, in a wildfire simulation test, the smoke particle characteristics after burning different typical vegetation are obtained through a typical vegetation burning characteristics test, wherein the smoke particle characteristics include the main components and proportions of smoke particles; the particle size distribution interval is determined based on the smoke particle characteristics, and the particle size distribution interval is divided into the particle size distribution interval. The particle size parameters of the smoke particles are used as experimental variables to prepare particle samples corresponding to different particle size parameters, namely the particle sample data; the particle samples are blown into the gap under simulated wildfire conditions using a simulation test platform to obtain the gap breakdown voltage under different conditions, namely the breakdown voltage data; the particle sample data and the corresponding breakdown voltage data are analyzed to obtain a correction relationship between the smoke particle size and the gap breakdown voltage, as well as a calculation formula for each correction coefficient in the correction relationship; the obtained correction relationship and the calculation formula for each correction coefficient are integrated into the initial risk assessment model of the overhead transmission line to obtain a wildfire gap breakdown risk assessment model. In the correction relationship, the correction coefficient of each gap area is determined according to the first gap breakdown voltage gradient and the second gap breakdown voltage gradient, the first gap breakdown voltage gradient being the gap breakdown voltage gradient in the initial state, and the second gap breakdown voltage gradient being the gap breakdown voltage gradient in the particle state.

[0062] Furthermore, the preparation method of the particle sample is specifically as follows: according to the test, the particle size distribution range of the smoke particles generated after the combustion of several typical vegetations is obtained, including D10, D50, and D90, and different typical vegetations are used to build vegetation piles of the same size, and the size of the wood pile is set to 1m*1m*0.15m. After the wood pile is ignited and fully burned and obvious smoke is generated, a smoke sample is collected using a test tube. When the smoke particles are in a suspended state, a particle size analyzer is used to analyze the particle size characteristics of the smoke particles in the test tube to obtain the particle size distribution data of the smoke particles in the suspended state; when the smoke particles are in a deposited state, a component analyzer is used to analyze the main components and proportions of the smoke particles in the test tube; based on the main components and proportions of the smoke particles, the raw materials for configuring the smoke particle sample are determined. Based on the artificial smear test, carbon particles, kaolin, and sodium chloride can be used to simulate the burning of carbon black, dust, and inorganic salts. After selecting the raw materials for preparing the smoke particle samples, combined with the particle size characteristics of the smoke particles, mainly based on the D10, D50, and D90 of the smoke particles as the particle size, the particle samples of the required particle size are configured.

[0063] As an example of an embodiment of the present invention, the target gap breakdown voltage calculation formula is determined based on particle sample data, breakdown voltage data and correction coefficients of different gap areas, and the correction coefficient of each gap area is determined based on the first gap breakdown voltage gradient and the second gap breakdown voltage gradient. Specifically, for each group of particle samples, the initial correction coefficients of each gap area corresponding to each group of particle samples are determined based on the first gap breakdown voltage gradient of each gap area and the second gap breakdown voltage gradient of each gap area; based on the particle sample data and the initial correction coefficients of each gap area corresponding to each group of particle samples, multivariate nonlinear regression fitting is performed to obtain the target correction coefficients corresponding to each gap area; based on the target correction coefficients corresponding to each gap area and the first gap breakdown voltage gradient corresponding to each gap area, the target gap breakdown voltage calculation formula is determined.

[0064] In this embodiment, by fitting each group of particle samples, the gap breakdown voltage gradients of the different gap regions corresponding to each group of particle samples can be obtained. Then, by fitting the gap breakdown voltage gradients of each gap region before and after the particle sample is input, the correction relationship between the smoke particle size and the breakdown voltage gradient of each gap region can be obtained, as well as a method for calculating the corresponding correction coefficient. Specifically, for each group of particle samples, the initial correction coefficients of each gap region corresponding to each group of particle samples are determined based on the first gap breakdown voltage gradient of each gap region before the particle sample is input, i.e., in the initial state; and the second gap breakdown voltage gradient of each gap region after the particle sample is input, i.e., in the particle state. Based on the initial correction coefficients of each gap region corresponding to each group of particle samples and the particle size parameters of each group of particle samples, a multivariate nonlinear regression fit is performed to obtain the target correction coefficients corresponding to each gap region. Based on the target correction coefficients corresponding to each gap region and the first gap breakdown voltage gradient corresponding to each gap region, a calculation formula for the target gap breakdown voltage is determined.

[0065] As an example of an embodiment of the present invention, the gap area includes a flame continuous area, a flame discontinuous area and a smoke area, and the initial correction coefficient includes a first correction coefficient corresponding to the flame discontinuous area and a second correction coefficient corresponding to the smoke area; the initial correction coefficient of each gap area corresponding to each group of the particle samples is determined according to the first gap breakdown voltage gradient of each gap area and the second gap breakdown voltage gradient of each gap area, specifically: for the flame continuous area, the first gap breakdown voltage gradient of the flame continuous area in the initial state is set to be equal to the second gap breakdown voltage gradient in the particle state; for each group of the particle samples, respectively obtain The area lengths of the flame continuous area, the flame discontinuous area and the smoke area; based on the initial gap breakdown voltage calculation formula, and based on each breakdown voltage corresponding to each group of the particle samples and the area length of each gap area, the second gap breakdown voltage gradient of the flame discontinuous area and the smoke area are determined respectively; according to the first gap breakdown voltage gradient corresponding to the flame discontinuous area and the second gap breakdown voltage gradient corresponding to the flame discontinuous area, the first correction coefficient corresponding to the flame discontinuous area is obtained; and according to the first gap breakdown voltage gradient corresponding to the smoke area and the second gap breakdown voltage gradient corresponding to the smoke area, the second correction coefficient corresponding to the smoke area is obtained.

[0066] In this embodiment, in a wildfire simulation test, the gaps in overhead transmission lines under wildfire conditions can be divided into a continuous flame zone, a discontinuous flame zone, and a smoke zone. Due to the high electrical conductivity and temperature of the flame body, smoke particles have a smaller impact on the insulation level degradation in the continuous and discontinuous flame zones. In the smoke zone, smoke particles have a greater impact, that is, the particles primarily affect the gap breakdown characteristics in the smoke and discontinuous flame zones, and have a smaller effect on the flame zone, where the resistance can reach megohms. Therefore, in this embodiment of the present invention, the first gap breakdown voltage gradient in the continuous flame zone in the initial state is set equal to the second gap breakdown voltage gradient in the particle state, that is, the correction coefficient for the continuous flame zone is 1.

[0067] Taking the gap breakdown voltage as the dependent variable and the length of each gap region as the independent variable, the calculation formula of the initial gap breakdown voltage is expressed as follows:

[0068]

[0069] Where: U is the breakdown voltage, in kV; E f 、E fs and E s are the gap breakdown voltage gradients of the flame continuous zone, flame discontinuous zone and smoke zone, in kV; H f 、 and H s are the lengths of the flame continuous zone, flame discontinuous zone and smoke zone, respectively, in meters;

[0070] For each particle sample group, as described above, the gap regions are divided according to their temperature characteristics, and the lengths of each gap region are determined. The corresponding breakdown voltage and the lengths of each gap region are then substituted into the initial gap breakdown voltage calculation formula to obtain the second gap breakdown voltage gradients for the flame discontinuity region and the smoke region, respectively, for each particle sample group. By fitting the gap breakdown voltage gradients for the flame discontinuity region and the smoke region before and after the particle sample input, a first correction coefficient for the gap breakdown voltage gradient in the flame discontinuity region and a second correction coefficient for the gap breakdown voltage gradient in the smoke region, based on the smoke particle size, are obtained.

[0071] As an example of an embodiment of the present invention, the target gap breakdown voltage calculation formula is specifically:

[0072] U=E f1 *H1+E fs1 *K′1*H fs +E s1 *K′2*H s ;

[0073] Where U is the gap breakdown voltage, in kV; Ef1 、E fs1 and E s1 are the first gap breakdown voltage gradients of the flame continuous zone, flame discontinuous zone and smoke zone, respectively, in kV; H1, H fs and H s where are the lengths of the flame continuous zone, flame discontinuous zone and smoke zone, respectively, in meters; K′1 and K′2 are the target correction coefficients of the flame discontinuous zone and smoke zone for the gap breakdown voltage, respectively.

[0074] In this embodiment, the target correction coefficient includes a first target correction coefficient corresponding to the flame continuous zone and a second target correction coefficient corresponding to the smoke zone. A multivariate nonlinear regression fitting is performed on the first correction coefficient and the second correction coefficient of each group of particle samples to obtain the first target correction coefficient and the second target correction coefficient. The initial gap breakdown voltage calculation formula is corrected according to the first target correction coefficient and the second target correction coefficient to obtain the target gap breakdown voltage calculation formula, which is expressed as follows:

[0075] U=E f1 *H1+E fs1 *K′1*H fs +E s1 *K′2*H s ;

[0076] Where U is the gap breakdown voltage, in kV; E f1 、E fs1 and E s1 are the first gap breakdown voltage gradients of the flame continuous zone, flame discontinuous zone and smoke zone, respectively, in kV; H1, H fs and H s are the lengths of the flame continuous area, flame discontinuous area, and smoke area, respectively, in meters; K′1 is the first target correction coefficient corresponding to the flame discontinuous area, and K′2 is the second target correction coefficient corresponding to the smoke area.

[0077] As an example of an embodiment of the present invention, the calculation formulas for the first correction coefficient and the second correction coefficient are specifically:

[0078]

[0079] Wherein, K1 is the first correction coefficient corresponding to the flame discontinuous area, and K2 is the second correction coefficient corresponding to the smoke area;

[0080] And, the formula for multivariate nonlinear regression fitting is specifically,

[0081]

[0082] Among them, D1, D2, and D3 are the corresponding particle sizes when the cumulative distribution proportion in each group of the particle samples reaches the first threshold, the second threshold, and the third threshold, and the first threshold, the second threshold, and the third threshold increase successively; a1, a2, and a3 are the proportions of the corresponding particle sizes; b1, b2, b3, c1, c2, and c3 are fitting coefficients.

[0083] In this embodiment, for each set of particle samples, a first correction coefficient for the smoke particle size in the flame discontinuous zone and a second correction coefficient for the smoke zone are obtained based on the gap breakdown voltage gradients in the flame discontinuous zone and the smoke zone before and after the particle sample is input. The calculation formulas for the first correction coefficient and the second correction coefficient are as follows:

[0084]

[0085] Wherein, K1 is the first correction coefficient corresponding to the flame discontinuous area, and K2 is the second correction coefficient corresponding to the smoke area;

[0086] Perform a multivariate nonlinear regression fit on the first correction coefficient, the second correction coefficient, the particle size, and the particle proportion corresponding to each group of particle samples to determine the fitting coefficient. A calculation method for determining the first target correction coefficient K′1 and the second target correction coefficient K′2 is determined based on the fitting coefficient. The formula for the multivariate nonlinear regression fit is expressed as follows:

[0087]

[0088] Among them, D1, D2, and D3 are the corresponding particle sizes when the cumulative distribution proportion in each group of the particle samples reaches the first threshold, the second threshold, and the third threshold, and the first threshold, the second threshold, and the third threshold increase successively; a1, a2, and a3 are the proportions of the corresponding particle sizes; b1, b2, b3, c1, c2, and c3 are fitting coefficients.

[0089] As an example of an embodiment of the present invention, the wildfire gap breakdown risk assessment model is obtained by training based on the target gap breakdown voltage calculation formula and historical operation and maintenance data, specifically:

[0090] The historical operation and maintenance data is input into the wildfire gap breakdown risk assessment model, so that the wildfire gap breakdown risk assessment model calculates the historical particle size data in the historical operation and maintenance data according to the target gap breakdown voltage calculation formula to obtain the gap breakdown voltage, and obtains a voltage comparison result by comparing the voltage peak in the historical operation and maintenance data with the gap breakdown voltage. The wildfire gap breakdown risk assessment model is trained according to the voltage comparison result and the preset risk classification standard.

[0091] In this embodiment, an initial risk assessment model for overhead transmission lines is constructed based on the target gap breakdown voltage calculation formula, and the historical operation and maintenance data of the overhead transmission lines are used to train the initial risk assessment model to improve the accuracy of the risk assessment model. In the initial risk assessment model, the target gap breakdown voltage calculation formula is used to calculate the gap breakdown voltage U at this time. G , and then obtain the phase-to-ground voltage peak value U at this time based on historical operation and maintenance data a , by comparing the phase-to-ground voltage peak value U a and gap breakdown voltage U G , obtain a voltage comparison result, and then grade the short-circuit breakdown risk of the overhead transmission line according to the voltage comparison result and the preset risk classification standard. Based on the above steps, the initial risk assessment model is iteratively trained until the iteration stop condition is met to obtain a wildfire gap breakdown risk assessment model, wherein the training method can be a common model training method adopted by those skilled in the art, and the present invention is not limited to this.

[0092] As an example of an embodiment of the present invention, the preset risk classification standard is specifically:

[0093] When the voltage comparison result is greater than a first threshold, the risk assessment result is low risk;

[0094] When the voltage comparison result is less than or equal to the first threshold and greater than the second threshold, the risk assessment result is medium risk;

[0095] When the voltage comparison result is less than or equal to the second threshold and greater than a third threshold, the risk assessment result is high risk;

[0096] When the voltage comparison result is less than or equal to a third threshold, the risk assessment result is an extremely high risk; wherein the first threshold, the second threshold, and the third threshold are determined according to the voltage peak value and decrease in sequence.

[0097] In this embodiment, the first threshold is set to 1.5U a , the second threshold is 1.2U a , the third threshold is 1.1U a Based on this, the risk results are divided as follows:

[0098] Low risk (large safety margin): When U G >1.5U a When , it means that the gap's withstand voltage is much higher than the line voltage, the possibility of breakdown is extremely low, and the line operation is relatively safe;

[0099] Medium risk (needs attention): When 1.5U a ≥U G >1.2Ua When the pressure resistance of the gap is relatively good, there is still a certain possibility of breakdown, especially in extreme weather or when the fire is intensified, and close monitoring is required;

[0100] High risk (precautions required): When 1.2U a ≥U G >1.1U a When the voltage is too low, it indicates that the possibility of gap breakdown has increased significantly and the line is close to the tolerance limit. Inspections and protective measures should be strengthened to reduce the risk of short-circuit tripping.

[0101] Very high risk (breakdown is very likely to occur): When U G ≤1.1U a When the gap is too short to withstand the line voltage, it is very easy to cause a short circuit breakdown under the influence of wildfire, which may cause the line to trip and even cause a large-scale power outage in the power grid. Emergency intervention measures should be taken immediately.

[0102] like Figure 2 The figure shows a test platform designed by the present invention to simulate the particle size gap breakdown characteristics of smoke particles. In this test platform, a typical 1m*1m*0.15m vegetation pile is placed below the conductor. Then, a particle infusion device is constructed using an insulated flame-retardant bracket, a fan, and an air duct. A funnel is secured to the air duct outlet using the insulated flame-retardant bracket, feeding particles at a constant rate. The funnel and air duct are securely bonded together with insulating tape. A baffle is located below the funnel, connected to a remote-controlled vehicle with a flame-retardant rope. This baffle is opened to allow particle infusion after the test begins. At the start of the test, the desired particle sample is poured into the funnel. A camera, infrared thermometer, and concentration detection device are activated. Alcohol is sprayed on the vegetation pile to ignite it. The camera angle is adjusted and video recording is prepared. The vegetation pile is ignited. Once combustion stabilizes, the fan is turned on. Once the wind speed stabilizes, the funnel baffle is opened to blow particles into the gap. Use the direct boost method to pressurize the gap, observe whether it breaks down during the process, record the breakdown voltage when the gap breaks down, observe the flame shape and smoke shape after the first breakdown, wait for the flame to stabilize, re-pressurize until the gap breaks down, record the breakdown voltage, and record 3 sets of data in total. After the vegetation pile is burned, stop the test, enter the site, first ground it, extinguish the fire, and clean up residual charcoal and other debris. Select the same particle size parameters as the previous steps, repeat the test twice, and obtain the test record results of 9 data points. Repeat the above process, change the particle size parameters for testing, obtain the required wildfire gap breakdown voltage corresponding to the different particle samples, and obtain the breakdown voltage data.

[0103] like Figure 3As shown, based on the above method embodiment, a corresponding system embodiment is provided; an embodiment of the present invention provides a gap breakdown risk assessment system 300, including: an acquisition module 301, an assessment module 302;

[0104] The acquisition module is configured to acquire a gap area of ​​the overhead transmission line to be evaluated, a plurality of particle size parameters under wildfire conditions, and a particle size ratio corresponding to each of the particle size parameters;

[0105] The evaluation module is used to input each of the particle size parameters and each of the particle size ratios into a wildfire gap breakdown risk assessment model and output a risk assessment result, wherein the wildfire gap breakdown risk assessment model is trained based on a target gap breakdown voltage calculation formula and historical operation and maintenance data, the target gap breakdown voltage calculation formula is determined based on particle sample data, breakdown voltage data, and correction coefficients of different gap areas, the particle sample data includes multiple groups of particle samples, and the particle size parameters and particle size ratios in each group of the particle samples are different, the breakdown voltage data includes multiple breakdown voltages, each of the breakdown voltages is determined based on each group of the particle samples, and the correction coefficient of each gap area is determined based on a first gap breakdown voltage gradient and a second gap breakdown voltage gradient, the first gap breakdown voltage gradient is the gap breakdown voltage gradient in the initial state, and the second gap breakdown voltage gradient is the gap breakdown voltage gradient in the particle state.

[0106] It can be understood that the above-mentioned system embodiment corresponds to the method embodiment of the present invention, which can implement the gap breakdown risk assessment method provided by any of the above-mentioned method embodiments of the present invention.

[0107] It should be noted that the system embodiments described above are merely illustrative, and some or all of the modules may be selected to achieve the objectives of the present embodiments as needed. Furthermore, in the drawings of the system embodiments provided herein, the connection relationships between modules indicate that they have communication connections, which may be implemented as one or more communication buses or signal lines. Persons of ordinary skill in the art can understand and implement the present invention without inventive effort.

[0108] Based on the above-mentioned embodiment of the gap breakdown risk assessment method, another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the gap breakdown risk assessment method of any embodiment of the present invention is implemented.

[0109] For example, in this embodiment, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to implement the present invention. The one or more module elements may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device.

[0110] The terminal device may be a computing device such as a desktop computer, a notebook computer, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0111] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, connecting various parts of the entire terminal device using various interfaces and lines.

[0112] Based on the above method embodiments, another embodiment of the present invention provides a computer-readable storage medium, including a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the gap breakdown risk assessment method described in any one of the above method embodiments of the present invention.

[0113] Wherein, the module / unit integrated in the device / terminal equipment, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0114] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A gap breakdown risk assessment method, characterized in that: include: Obtaining a gap area of ​​an overhead transmission line to be evaluated, a plurality of particle size parameters under wildfire conditions, and a particle size ratio corresponding to each of the particle size parameters; Each of the particle size parameters and each of the particle size ratios is input into a wildfire gap breakdown risk assessment model, and a risk assessment result is output, wherein the wildfire gap breakdown risk assessment model is trained based on a target gap breakdown voltage calculation formula and historical operation and maintenance data, the target gap breakdown voltage calculation formula is determined based on particle sample data, breakdown voltage data, and correction coefficients for different gap areas, the particle sample data includes multiple groups of particle samples, and the particle size parameters and particle size ratios in each group of the particle samples are different, the breakdown voltage data includes multiple breakdown voltages, each of the breakdown voltages is determined based on each group of the particle samples, and the correction coefficient of each gap area is determined based on a first gap breakdown voltage gradient and a second gap breakdown voltage gradient, the first gap breakdown voltage gradient is the gap breakdown voltage gradient in the initial state, and the second gap breakdown voltage gradient is the gap breakdown voltage gradient in the particle state.

2. The gap breakdown risk assessment method according to claim 1, wherein: The target gap breakdown voltage calculation formula is determined based on particle sample data, breakdown voltage data, and correction coefficients for different gap regions. The correction coefficient for each gap region is determined based on the first gap breakdown voltage gradient and the second gap breakdown voltage gradient, specifically: For each group of particle samples, determining an initial correction coefficient of each gap region corresponding to each group of particle samples according to a first gap breakdown voltage gradient of each gap region and a second gap breakdown voltage gradient of each gap region; Based on the particle sample data and the initial correction coefficients of the gap regions corresponding to each group of the particle samples, a multivariate nonlinear regression fitting is performed to obtain a target correction coefficient corresponding to each gap region; The target gap breakdown voltage calculation formula is determined according to the target correction coefficient corresponding to each gap region and the first gap breakdown voltage gradient corresponding to each gap region.

3. The gap breakdown risk assessment method according to claim 2, wherein: The gap area includes a flame continuous area, a flame discontinuous area, and a smoke area, and the initial correction coefficient includes a first correction coefficient corresponding to the flame discontinuous area and a second correction coefficient corresponding to the smoke area; The initial correction coefficient of each gap region corresponding to each group of the particle samples is determined according to the first gap breakdown voltage gradient of each gap region and the second gap breakdown voltage gradient of each gap region, specifically: For the flame continuous zone, setting a first gap breakdown voltage gradient of the flame continuous zone in an initial state to be equal to a second gap breakdown voltage gradient in a particle state; For each group of particle samples, respectively obtaining the lengths of the flame continuous area, the flame discontinuous area, and the smoke area; Based on the initial gap breakdown voltage calculation formula, and based on each breakdown voltage corresponding to each group of particle samples and the region length of each gap region, respectively determining the second gap breakdown voltage gradient of the flame discontinuous region and the smoke region; A first correction coefficient corresponding to the flame discontinuous zone is obtained based on the first gap breakdown voltage gradient corresponding to the flame discontinuous zone and the second gap breakdown voltage gradient corresponding to the flame discontinuous zone; and a second correction coefficient corresponding to the smoke zone is obtained based on the first gap breakdown voltage gradient corresponding to the smoke zone and the second gap breakdown voltage gradient corresponding to the smoke zone.

4. The gap breakdown risk assessment method according to claim 1, wherein: The wildfire gap breakdown risk assessment model is trained based on the target gap breakdown voltage calculation formula and historical operation and maintenance data, specifically: The historical operation and maintenance data is input into the wildfire gap breakdown risk assessment model, so that the wildfire gap breakdown risk assessment model calculates the historical particle size data in the historical operation and maintenance data according to the target gap breakdown voltage calculation formula to obtain the gap breakdown voltage, and obtains a voltage comparison result by comparing the voltage peak in the historical operation and maintenance data with the gap breakdown voltage. The wildfire gap breakdown risk assessment model is trained according to the voltage comparison result and the preset risk classification standard.

5. The gap breakdown risk assessment method according to claim 4, wherein: The preset risk classification standards are specifically: When the voltage comparison result is greater than a first threshold, the risk assessment result is low risk; When the voltage comparison result is less than or equal to the first threshold and greater than the second threshold, the risk assessment result is medium risk; When the voltage comparison result is less than or equal to the second threshold and greater than a third threshold, the risk assessment result is high risk; When the voltage comparison result is less than or equal to a third threshold, the risk assessment result is an extremely high risk; wherein the first threshold, the second threshold, and the third threshold are determined according to the voltage peak value and decrease in sequence.

6. The gap breakdown risk assessment method according to claim 3, wherein: The target gap breakdown voltage calculation formula is specifically: U=E f1 *H1+E fs1 *K′1*H fs +E s1 *K′2*H s ; Where U is the gap breakdown voltage, in kV; E f1 、E fs1 and E s1 are the first gap breakdown voltage gradients of the flame continuous zone, flame discontinuous zone and smoke zone, respectively, in kV; H1, H fs and H s where are the lengths of the flame continuous zone, flame discontinuous zone and smoke zone, respectively, in meters; K′1 and K′2 are the target correction coefficients of the flame discontinuous zone and smoke zone for the gap breakdown voltage, respectively.

7. The gap breakdown risk assessment method according to claim 6, wherein: The calculation formulas for the first correction coefficient and the second correction coefficient are specifically: Wherein, K1 is the first correction coefficient corresponding to the flame discontinuous area, and K2 is the second correction coefficient corresponding to the smoke area; And, the formula for multivariate nonlinear regression fitting is specifically, Among them, D1, D2, and D3 are the corresponding particle sizes when the cumulative distribution proportion in each group of the particle samples reaches the first threshold, the second threshold, and the third threshold, and the first threshold, the second threshold, and the third threshold increase successively; a1, a2, and a3 are the proportions of the corresponding particle sizes; b1, b2, b3, c1, c2, and c3 are fitting coefficients.

8. A gap breakdown risk assessment system, characterized in that: include: Access modules and assessment modules; The acquisition module is configured to acquire a gap area of ​​the overhead transmission line to be evaluated, a plurality of particle size parameters under wildfire conditions, and a particle size ratio corresponding to each of the particle size parameters; The evaluation module is used to input each of the particle size parameters and each of the particle size ratios into a wildfire gap breakdown risk assessment model and output a risk assessment result, wherein the wildfire gap breakdown risk assessment model is trained based on a target gap breakdown voltage calculation formula and historical operation and maintenance data, the target gap breakdown voltage calculation formula is determined based on particle sample data, breakdown voltage data, and correction coefficients of different gap areas, the particle sample data includes multiple groups of particle samples, and the particle size parameters and particle size ratios in each group of the particle samples are different, the breakdown voltage data includes multiple breakdown voltages, each of the breakdown voltages is determined based on each group of the particle samples, and the correction coefficient of each gap area is determined based on a first gap breakdown voltage gradient and a second gap breakdown voltage gradient, the first gap breakdown voltage gradient is the gap breakdown voltage gradient in the initial state, and the second gap breakdown voltage gradient is the gap breakdown voltage gradient in the particle state.

9. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, the method for assessing gap breakdown risk according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that include: A stored computer program, wherein when the computer program is run, the device where the computer-readable storage medium is located is controlled to execute the gap breakdown risk assessment method according to any one of claims 1 to 7.

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