Method, System, Device and Storage Medium for Evaluating Insulation Level of Circuit Breaker under Lightning Strike

Abstract

The present invention relates to the technical field of lightning protection for substation equipment in power systems, and discloses a method, system, device and storage medium for evaluating the insulation level of a circuit breaker under lightning strikes. According to the in-station equipment data, the present invention determines the lightning withstand levels of the incoming line towers under lightning back-strikes and lightning shielding failures, takes the incoming line tower with the lowest lightning withstand level under lightning back-strikes as the first target tower, and takes the incoming line towers with lightning withstand levels lower than the corresponding maximum shielding failure lightning current under lightning shielding failures as the second target towers. Furthermore, a lightning simulation calculation model is established. In the model, a back-strike simulation is carried out on the first target tower using the back-strike lightning current, and a shielding failure simulation is carried out on the second target tower using the shielding failure lightning current. The maximum overvoltage level of the circuit breaker is determined from the obtained simulation results. Finally, the insulation level of the circuit breaker under lightning strikes is determined according to the maximum overvoltage level and the insulation safety margin of the circuit breaker. The present invention can quickly and effectively determine the insulation level of the circuit breaker under lightning strikes.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning protection for substation equipment in power systems, and particularly to a method, system, device, and storage medium for evaluating the insulation level of a circuit breaker under lightning strikes. Background Art

[0002] After a lightning strike on the line, when the circuit breaker cuts off the short-circuit current, if another lightning flashover occurs, it will cause the arc to reignite, thus triggering a power accident and seriously threatening the safe and stable operation of the power grid. How to quickly and effectively determine the insulation level of the circuit breaker under lightning strikes is of great significance for calculating the lightning failure rate of the circuit breaker and taking targeted protection measures to ensure its safe and stable operation. Summary of the Invention

[0003] The present invention provides a method, system, device, and storage medium for evaluating the insulation level of a circuit breaker under lightning strikes, and solves the technical problem of how to quickly and effectively determine the insulation level of the circuit breaker under lightning strikes.

[0004] A first aspect of the present invention provides a method for evaluating the insulation level of a circuit breaker under lightning strikes, including:

[0005] Obtaining in-station equipment data, where the in-station equipment data includes lines, incoming line section towers, insulator strings, topography, substation electrical floor plans, and relevant parameters of the equipment;

[0006] Determining the lightning withstand levels of the incoming line section towers under lightning back-strikes and lightning shielding failures according to the in-station equipment data, taking the incoming line section tower with the lowest lightning withstand level under lightning back-strikes as the first target tower, and taking the incoming line section towers with lightning withstand levels lower than the corresponding maximum shielding lightning current under lightning shielding failures as the second target towers;

[0007] Establishing a lightning simulation calculation model in the electromagnetic transient program according to the in-station equipment data, performing a back-strike simulation on the first target tower with a back-strike lightning current in the lightning simulation calculation model, and performing a shielding failure simulation on the second target tower with a shielding lightning current to obtain the overvoltage levels of the circuit breaker under different back-strike and shielding failure conditions;

[0008] Determining the maximum overvoltage level of the circuit breaker according to the overvoltage levels of the circuit breaker under different back-strike and shielding failure conditions, and determining the insulation level of the circuit breaker under lightning strikes according to the maximum overvoltage level and the insulation safety margin of the circuit breaker.

[0009] According to an implementable manner of the first aspect of the present invention, the determining the lightning withstand levels of the incoming line section towers under lightning back-strikes and lightning shielding failures according to the in-station equipment data includes:

[0010] Perform simulation calculations on typical towers of different voltage levels, and establish a first quantitative function expression between the lightning withstand level of the tower under lightning back-stroke and the tower height, tower grounding resistance, and tower insulation distance according to the obtained simulation calculation results;

[0011] Select the incoming line towers within the preset distance range of the substation according to the in-station equipment data, obtain the height, grounding resistance, and insulation distance of the selected incoming line towers, and input the first quantitative function expression to obtain the lightning withstand level of the selected incoming line towers under lightning back-stroke.

[0012] According to an implementable manner of the first aspect of the present invention, the determining the lightning withstand levels of the incoming line towers under lightning back-stroke and lightning shielding failure according to the in-station equipment data further includes:

[0013] Perform simulation calculations on typical towers of different voltage levels, and establish a second quantitative function expression between the lightning withstand level of the tower under lightning shielding failure and the tower insulation distance according to the obtained simulation calculation results;

[0014] Obtain the insulation distance of the selected incoming line towers, and input the second quantitative function expression to obtain the lightning withstand level of the selected incoming line towers under lightning shielding failure.

[0015] According to an implementable manner of the first aspect of the present invention, the determining the breaker insulation level under lightning strike according to the maximum overvoltage level and the insulation safety margin of the breaker includes:

[0016] Calculate the breaker insulation level under lightning strike according to the following formula:

[0017]

[0018] In the formula, U CB is the breaker insulation level under lightning strike, U max is the maximum overvoltage level, is the insulation safety margin of the breaker.

[0019] A breaker insulation level evaluation system provided by the second aspect of the present invention includes:

[0020] A data acquisition module for acquiring in-station equipment data, where the in-station equipment data includes relevant parameters of lines, incoming line towers, insulator strings, terrain and landforms, substation electrical floor plans, and equipment;

[0021] The target tower determination module is used to determine the lightning withstand levels of the incoming line towers under lightning back-striking and lightning shielding failure according to the in-station equipment data, take the incoming line tower with the lowest lightning withstand level under lightning back-striking as the first target tower, and take the incoming line tower with a lightning withstand level lower than the corresponding maximum shielding failure lightning current under lightning shielding failure as the second target tower;

[0022] The simulation calculation module is used to establish a lightning simulation calculation model in the electromagnetic transient program according to the in-station equipment data, perform back-striking simulation on the first target tower with a back-striking lightning current in the lightning simulation calculation model, and perform shielding failure simulation on the second target tower with a shielding failure lightning current to obtain the overvoltage levels of the circuit breaker under different back-striking and shielding failure conditions;

[0023] The insulation level determination module is used to determine the maximum overvoltage level of the circuit breaker according to the overvoltage levels of the circuit breaker under different back-striking and shielding failure conditions, and determine the insulation level of the circuit breaker under lightning strikes according to the maximum overvoltage level and the insulation safety margin of the circuit breaker.

[0024] According to an implementable manner of the second aspect of the present invention, the target tower determination module includes:

[0025] The first expression construction unit is used to perform simulation calculations on typical towers of different voltage levels, and establish a first quantitative function expression between the lightning withstand level of the tower under lightning back-striking, the tower height, the tower grounding resistance, and the tower insulation distance according to the obtained simulation calculation results;

[0026] The first tower lightning withstand level determination unit is used to select the incoming line towers within the preset distance range of the substation according to the in-station equipment data, obtain the height, grounding resistance, and insulation distance of the selected incoming line towers, and input them into the first quantitative function expression to obtain the lightning withstand levels of the selected incoming line towers under lightning back-striking.

[0027] According to an implementable manner of the second aspect of the present invention, the target tower determination module further includes:

[0028] The second expression construction unit is used to perform simulation calculations on typical towers of different voltage levels, and establish a second quantitative function expression between the lightning withstand level of the tower under lightning shielding failure and the tower insulation distance according to the obtained simulation calculation results;

[0029] The second tower lightning withstand level determination unit is used to obtain the insulation distance of the selected incoming line towers, and input them into the second quantitative function expression to obtain the lightning withstand levels of the selected incoming line towers under lightning shielding failure.

[0030] According to an implementable manner of the second aspect of the present invention, the insulation level determination module includes:

[0031] A calculation unit for calculating the insulation level of the circuit breaker under lightning strikes according to the following formula:

[0032]

[0033] In the formula, U CB is the insulation level of the circuit breaker under lightning strikes, and U max is the maximum overvoltage level, is the insulation safety margin of the circuit breaker.

[0034] The third aspect of the present invention provides an equipment for evaluating the insulation level of a circuit breaker under lightning strikes, including:

[0035] A memory for storing instructions; wherein, the instructions are used to implement the method for evaluating the insulation level of the circuit breaker under lightning strikes described in any one of the above realizable manners;

[0036] A processor for executing the instructions in the memory.

[0037] The fourth aspect of the present invention is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the method for evaluating the insulation level of the circuit breaker under lightning strikes described in any one of the above realizable manners.

[0038] From the above technical solutions, it can be seen that the present invention has the following advantages:

[0039] The present invention determines the lightning withstand levels of the incoming line towers under lightning back-strikes and lightning shielding failures based on the in-station equipment data, takes the incoming line tower with the lowest lightning withstand level under lightning back-strikes as the first target tower, and takes the incoming line tower with a lightning withstand level lower than the corresponding maximum shielding failure lightning current under lightning shielding failures as the second target tower. Then, a lightning simulation calculation model is established in the electromagnetic transient program, and in the model, a back-strike simulation is carried out on the first target tower using the back-strike lightning current, and a shielding failure simulation is carried out on the second target tower using the shielding failure lightning current to obtain the overvoltage levels of the circuit breaker under different back-strike and shielding failure conditions, and the maximum overvoltage level of the circuit breaker is determined from them. Finally, the insulation level of the circuit breaker under lightning strikes is determined based on the maximum overvoltage level and the insulation safety margin of the circuit breaker; by using the above method to determine the insulation withstand level of the circuit breaker, compared with the traditional method of obtaining the overvoltage level of the circuit breaker by carrying out shielding failure and back-strike simulation calculations on each incoming line tower, the efficiency is greatly improved, and the accuracy of the evaluation is hardly affected at all, solving the technical problem of how to quickly and effectively determine the insulation level of the circuit breaker under lightning strikes. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0041] Figure 1 The flowchart of a method for evaluating the insulation level of a circuit breaker under lightning strikes provided by an optional embodiment of the present invention;

[0042] Figure 2 The structural connection block diagram of a system for evaluating the insulation level of a circuit breaker under lightning strikes provided by an optional embodiment of the present invention.

[0043] Reference numerals:

[0044] 1 - Data acquisition module; 2 - Target tower determination module; 3 - Simulation calculation module; 4 - Insulation level determination module. Detailed implementation manners

[0045] The embodiments of the present invention provide a method, a system, a device, and a storage medium for evaluating the insulation level of a circuit breaker under lightning strikes, which are used to solve the technical problem of how to quickly and effectively determine the insulation level of a circuit breaker under lightning strikes.

[0046] To make the objectives, features, and advantages of the present invention more obvious and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0047] The present invention provides a method for evaluating the insulation level of a circuit breaker under lightning strikes.

[0048] Please refer to Figure 1 , Figure 1 which shows the flowchart of a method for evaluating the insulation level of a circuit breaker under lightning strikes provided by an embodiment of the present invention.

[0049] A method for evaluating the insulation level of a circuit breaker under lightning strikes provided by an embodiment of the present invention includes steps S1 - S4.

[0050] Step S1, obtain the in-station equipment data, where the in-station equipment data includes lines, incoming line section towers, insulator strings, topography, substation electrical floor plans, and relevant parameters of the equipment.

[0051] When collecting the data of in-station equipment, it is preferable to collect the data of all lines, towers, insulator strings, topography and geomorphology within 2 km of the incoming line section of the substation, as well as the relevant parameters of the substation electrical floor plan and equipment.

[0052] Step S2: Determine the lightning withstand levels of the towers in the incoming line section under lightning back-stroke and lightning shielding failure according to the in-station equipment data. Take the tower with the lowest lightning withstand level under lightning back-stroke in the incoming line section as the first target tower, and take the tower in the incoming line section with a lightning shielding failure withstand level lower than the corresponding maximum shielding failure lightning current as the second target tower.

[0053] In an implementable manner, the determining the lightning withstand levels of the towers in the incoming line section under lightning back-stroke and lightning shielding failure according to the in-station equipment data includes:

[0054] Perform simulation calculations on typical towers of different voltage levels, and establish a first quantitative function expression between the lightning withstand level of the tower under lightning back-stroke and the tower height, tower grounding resistance, and tower insulation distance according to the obtained simulation calculation results;

[0055] Select the towers in the incoming line section within the preset distance range of the substation according to the in-station equipment data, obtain the height, grounding resistance, and insulation distance of the selected towers in the incoming line section, and input them into the first quantitative function expression to obtain the lightning withstand level of the selected towers in the incoming line section under lightning back-stroke.

[0056] Among them, when performing simulation calculations on typical towers of different voltage levels, typically, typical towers of different voltage levels in the range of 110 kV - 500 kV can be selected for simulation calculations.

[0057] For lightning back-stroke, the main factors affecting the lightning withstand level of the tower against back-stroke are the tower height, tower grounding resistance, and tower insulation distance. In this embodiment, based on these three factors, simulation calculations are performed on typical towers of different voltage levels. Based on a large number of simulation analysis results, a certain mathematical method is used for data fitting to obtain the quantitative function relationship expression between the lightning withstand level of the tower against back-stroke and the tower height, tower grounding resistance, and tower insulation distance, that is, this first quantitative function expression. Among them, existing mathematical methods can be used for data fitting to obtain the quantitative function relationship expression, and this embodiment does not limit this. This first quantitative function expression can be expressed as:

[0058] I f = f(h, R, d)

[0059] In the formula, I f represents the lightning withstand level of the tower under lightning back-stroke, h is the tower height, R is the tower grounding resistance, d is the tower insulation distance, and f represents the function.

[0060] The incoming line towers g within 2 km of the substation can be selected 1 , g 2 , …, g n (1 < n ≤ 10) to determine the first target tower. Based on the above method, input g 1 , g 2 , …, g n (1 < n ≤ 10) the tower height, tower grounding resistance, and tower insulation distance parameters into the first quantitative function expression to obtain the back-striking lightning withstand level I f1 , I f2 , …, I fn of the incoming line towers within 2 km of the substation. Compare the magnitudes of I f1 , I f2 , …, I fn , and select the tower with the minimum back-striking lightning withstand level as the first target tower.

[0061] In an implementable manner, the method for determining the lightning withstand levels of the incoming line towers under lightning back-strike and lightning shielding failure according to the in-station equipment data further includes:

[0062] Perform simulation calculations on typical towers of different voltage levels, and establish a second quantitative function expression between the lightning shielding failure withstand level of the tower and the tower insulation distance based on the obtained simulation calculation results;

[0063] Obtain the insulation distance of the selected incoming line towers, and input the second quantitative function expression to obtain the lightning shielding failure withstand level of the selected incoming line towers.

[0064] Among them, the incoming line towers g within 2 km of the substation can be selected 1 , g 2 , …, g n (1 < n ≤ 10) to determine the second target tower. For lightning shielding failure, since the lightning current is selected as the maximum shielding failure lightning current I rmax of the tower during simulation, it is first necessary to calculate the maximum shielding failure lightning current I 1 , g 2 , …, g n (1 < n ≤ 10) of the incoming line towers according to the electrogeometric model. rmax1 , I rmax2 , …, I rmaxn . Similarly, it is necessary to determine the shielding failure withstand levels I 1 , g 2 , …, g n (1 < n ≤ 10) of the incoming line towers. r1 , I r2 , …, I rn (1 < n ≤ 10).

[0065] Since the lightning withstand level under lightning shielding failure is basically determined by the tower insulation distance, the quantitative function expression between the lightning withstand level of the tower under lightning shielding failure and the tower insulation distance can also be obtained by using a certain data fitting method based on the simulation calculation results of typical towers with different voltage levels from 110 kV to 500 kV, that is, the second quantitative function expression.

[0066] Among them, the second quantitative function expression can be expressed as:

[0067] I r = f(d)

[0068] In the formula, I r represents the lightning withstand level of the tower under lightning shielding failure, d is the tower insulation distance, and f represents a function.

[0069] Furthermore, by comparing the magnitudes between II r1 and I rmax1 , I r2 and I rmax2 , …, I rn and I rmaxn , for a certain incoming line section tower k (1 < k ≤ 10), if there is I rk > I rmaxk , it indicates that the probability of flashover of the incoming line section tower during lightning current shielding failure is very small and can be ignored in the simulation calculation. In this way, only the shielding failure conditions of the towers with I rk < I rmaxk need to be considered during the simulation calculation.

[0070] Step S3: Establish a lightning simulation calculation model in the electromagnetic transient program according to the in-station equipment data. In the lightning simulation calculation model, use the back-stroke lightning current to simulate the back-stroke of the first target tower, and use the shielding failure lightning current to simulate the shielding failure of the second target tower to obtain the overvoltage levels of the circuit breaker under different back-stroke and shielding failure conditions.

[0071] Among them, after establishing the lightning simulation calculation model in the electromagnetic transient program, the standard recommended lightning current model can be used to strike and back-stroke the target tower. Here, only the target tower with the lowest back-stroke lightning withstand level (i.e., the first target tower) is considered during the back-stroke simulation calculation, and only the towers with a shielding failure lightning withstand level less than the maximum shielding failure lightning current (i.e., the second target tower) are considered during the shielding failure simulation calculation.

[0072] As a specific implementation, when establishing a lightning simulation calculation model, a lightning current model can be established using the Heidler wave in the electromagnetic transient program; a line tower model can be established using a multi-wave impedance model in the electromagnetic transient program; an insulator string flashover model can be established using the leader development method in the electromagnetic transient program; a tower grounding resistance model can be established using a concentrated resistance model in the electromagnetic transient program; the operation mode of one line and one transformer can be adopted in the electromagnetic transient program to simulate each device in the substation, the entrance capacitance can be used to equivalently simulate each device in the substation, and the wave impedance can be used to equivalently simulate the connection lines between devices in the substation to establish a substation device model; combining the lightning current model, the line tower model, the insulator string flashover model, the tower grounding resistance model, and the substation device model to establish a lightning simulation calculation model.

[0073] It should be noted that in the embodiments of the present invention, the lightning current model, the line tower model, the insulator string flashover model, the tower grounding resistance model, and the substation device model can also be constructed according to other existing model establishment methods, and then combined to obtain a lightning simulation calculation model.

[0074] Step S4, determine the maximum overvoltage level of the circuit breaker according to the overvoltage levels of the circuit breaker under different back-stroke and shielding failure conditions, and determine the insulation level of the circuit breaker under lightning strikes according to the maximum overvoltage level and the insulation safety margin of the circuit breaker.

[0075] In an implementable manner, the determining the insulation level of the circuit breaker under lightning strikes according to the maximum overvoltage level and the insulation safety margin of the circuit breaker includes:

[0076] Calculate the insulation level of the circuit breaker under lightning strikes according to the following formula:

[0077]

[0078] In the formula, U CB is the insulation level of the circuit breaker under lightning strikes, U max is the maximum overvoltage level, is the insulation safety margin of the circuit breaker.

[0079] As a preferred implementation, take an insulation safety margin of 15% according to the suggestions given in the national standard GB / T 311.2-2013 "Insulation Coordination Part 2: Application Guide". Furthermore, the calculation formula for the insulation level of the circuit breaker under lightning strikes is: U CB = 1.15U max .

[0080] Using the above method to determine the insulation withstand level of the circuit breaker, compared with the traditional method of simulating shielding failure and back flashover for each tower in the incoming line section, the efficiency is greatly improved. The improvement in efficiency is mainly reflected in two aspects. One is the determination of the lightning withstand level of the tower. In the past, the lightning withstand level of the tower had to be determined through multiple simulation tests, while the method proposed in the above embodiments of the present invention can be directly calculated based on mathematical formulas, significantly improving the calculation efficiency. The other is that during simulation, only the target towers in the incoming line section need to be calculated, and other towers do not need to be considered, avoiding a large number of ineffective simulation calculations. Moreover, the accuracy of the circuit breaker insulation level assessment is hardly affected compared with the traditional method.

[0081] The present invention also provides a system for evaluating the insulation level of a circuit breaker under lightning strikes.

[0082] Please refer to Figure 2 , Figure 2 which shows the structural connection block diagram of a system for evaluating the insulation level of a circuit breaker under lightning strikes provided by an embodiment of the present invention.

[0083] An embodiment of the present invention provides a system for evaluating the insulation level of a circuit breaker under lightning strikes, including:

[0084] A data acquisition module 1, configured to acquire in-station equipment data, where the in-station equipment data includes lines, towers in the incoming line section, insulator strings, topography, electrical floor plan of the substation, and relevant parameters of the equipment;

[0085] A target tower determination module 2, configured to determine the lightning withstand levels of the towers in the incoming line section under lightning back flashover and shielding failure according to the in-station equipment data, take the tower in the incoming line section with the lowest lightning withstand level under lightning back flashover as the first target tower, and take the tower in the incoming line section with a lightning withstand level lower than the corresponding maximum shielding failure lightning current under shielding failure as the second target tower;

[0086] A simulation calculation module 3, configured to establish a lightning simulation calculation model in the electromagnetic transient program according to the in-station equipment data, perform back flashover simulation on the first target tower using the back flashover lightning current in the lightning simulation calculation model, and perform shielding failure simulation on the second target tower using the shielding failure lightning current, to obtain the overvoltage levels of the circuit breaker under different back flashover and shielding failure conditions;

[0087] An insulation level determination module 4, configured to determine the maximum overvoltage level of the circuit breaker according to the overvoltage levels of the circuit breaker under different back flashover and shielding failure conditions, and determine the insulation level of the circuit breaker under lightning strikes according to the maximum overvoltage level and the insulation safety margin of the circuit breaker.

[0088] In an implementable manner, the target tower determination module 2 includes:

[0089] A first expression construction unit for simulating and calculating typical power towers with different voltage levels, and establishing a first quantitative function expression between the lightning withstand level of the power tower under lightning back-strike, the height of the power tower, the grounding resistance of the power tower, and the insulation distance of the power tower according to the obtained simulation calculation results;

[0090] A first power tower lightning withstand level determination unit for selecting the incoming line power towers within the preset distance range of the substation according to the in-station equipment data, obtaining the height, grounding resistance, and insulation distance of the selected incoming line power towers, and inputting the first quantitative function expression to obtain the lightning withstand level of the selected incoming line power towers under lightning back-strike.

[0091] In an implementable manner, the target power tower determination module 2 further includes:

[0092] A second expression construction unit for simulating and calculating typical power towers with different voltage levels, and establishing a second quantitative function expression between the lightning withstand level of the power tower under lightning shielding failure and the insulation distance of the power tower according to the obtained simulation calculation results;

[0093] A second power tower lightning withstand level determination unit for obtaining the insulation distance of the selected incoming line power towers, and inputting the second quantitative function expression to obtain the lightning withstand level of the selected incoming line power towers under lightning shielding failure.

[0094] In an implementable manner, the insulation level determination module 4 includes:

[0095] A calculation unit for calculating the insulation level of the circuit breaker under lightning strike according to the following formula:

[0096]

[0097] wherein, U CB is the insulation level of the circuit breaker under lightning strike, U max is the maximum overvoltage level, is the insulation safety margin of the circuit breaker.

[0098] The present invention also provides an evaluation device for the insulation level of a circuit breaker under lightning strike, including:

[0099] A memory for storing instructions; wherein, the instructions are used to implement the method for evaluating the insulation level of a circuit breaker under lightning strike as described in any one of the above embodiments;

[0100] A processor for executing the instructions in the memory.

[0101] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the method for evaluating the insulation level of a circuit breaker under lightning strikes described in any one of the above embodiments.

[0102] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described system, device, and module can refer to the corresponding processes in the foregoing method embodiments, and the specific beneficial effects of the above-described system, device, and module can refer to the corresponding beneficial effects in the foregoing method embodiments, which will not be elaborated herein.

[0103] In several embodiments provided by the present application, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0104] The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical modules, that is, they can be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0105] In addition, in each embodiment of the present invention, the functional modules can be integrated in a processing module, or each module can exist physically alone, or two or more modules can be integrated in one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules.

[0106] If the above integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. And the foregoing storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs and other various media that can store program codes.

[0107] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the insulation level of a circuit breaker under lightning strikes, characterized in that, it includes: Obtain in-station equipment data, where the in-station equipment data includes lines, incoming line section towers, insulator strings, topography, substation electrical floor plans, and relevant parameters of the equipment; Determine the lightning withstand levels of the incoming line section towers under lightning back-strikes and lightning shielding failures according to the in-station equipment data. Take the incoming line section tower with the lowest lightning withstand level under lightning back-strikes as the first target tower, and take the incoming line section tower with a lightning withstand level lower than the corresponding maximum shielding failure lightning current under lightning shielding failures as the second target tower; Establish a lightning simulation calculation model in the electromagnetic transient program according to the in-station equipment data. In the lightning simulation calculation model, use the back-strike lightning current to simulate the back-strike of the first target tower, and use the shielding failure lightning current to simulate the shielding failure of the second target tower to obtain the overvoltage levels of the circuit breaker under different back-strike and shielding failure conditions; Determine the maximum overvoltage level of the circuit breaker according to the overvoltage levels of the circuit breaker under different back-strike and shielding failure conditions, and determine the insulation level of the circuit breaker under lightning strikes according to the maximum overvoltage level and the insulation safety margin of the circuit breaker.

2. The method for evaluating the insulation level of a circuit breaker under lightning strikes according to claim 1, characterized in that, The determination of the lightning withstand levels of the incoming line section towers under lightning back-strikes and lightning shielding failures according to the in-station equipment data includes: Perform simulation calculations on typical towers of different voltage levels, and establish a first quantitative function expression between the lightning withstand level of the tower under lightning back-strikes and the tower height, tower grounding resistance, and tower insulation distance according to the obtained simulation calculation results; Select the incoming line section towers within the preset distance range of the substation according to the in-station equipment data, obtain the heights, grounding resistances, and insulation distances of the selected incoming line section towers, and input them into the first quantitative function expression to obtain the lightning withstand levels of the selected incoming line section towers under lightning back-strikes.

3. The method for evaluating the insulation level of a circuit breaker under lightning strikes according to claim 2, characterized in that, The determination of the lightning withstand levels of the incoming line section towers under lightning back-strikes and lightning shielding failures according to the in-station equipment data further includes: Perform simulation calculations on typical towers of different voltage levels, and establish a second quantitative function expression between the lightning withstand level of the tower under lightning shielding failures and the tower insulation distance according to the obtained simulation calculation results; Obtain the insulation distances of the selected incoming line section towers, and input them into the second quantitative function expression to obtain the lightning withstand levels of the selected incoming line section towers under lightning shielding failures.

4. The method for evaluating the insulation level of a circuit breaker under lightning strikes according to claim 1, characterized in that, The determination of the insulation level of the circuit breaker under lightning strikes according to the maximum overvoltage level and the insulation safety margin of the circuit breaker includes: Calculate the insulation level of the circuit breaker under lightning strikes according to the following formula: Wherein, U CB is the insulation level of the circuit breaker under lightning strike, and U max is the maximum overvoltage level, is the insulation safety margin of the circuit breaker.

5. A system for evaluating the insulation level of a circuit breaker under lightning strikes, characterized in that, it includes: A data acquisition module for obtaining in-station equipment data, where the in-station equipment data includes lines, incoming line section towers, insulator strings, topography, substation electrical floor plans, and relevant parameters of the equipment; The target tower determination module is used to determine the lightning withstand levels of the incoming line towers under lightning back-striking and lightning shielding failure according to the in-station equipment data, take the incoming line tower with the lowest lightning withstand level under lightning back-striking as the first target tower, and take the incoming line tower with a lightning shielding failure withstand level lower than the corresponding maximum shielding failure lightning current as the second target tower; The simulation calculation module is used to establish a lightning simulation calculation model in the electromagnetic transient program according to the in-station equipment data, perform a back-striking simulation on the first target tower using a back-striking lightning current in the lightning simulation calculation model, and perform a shielding failure simulation on the second target tower using a shielding failure lightning current to obtain the overvoltage levels of the circuit breaker under different back-striking and shielding failure conditions; The insulation level determination module is used to determine the maximum overvoltage level of the circuit breaker according to the overvoltage levels of the circuit breaker under different back-striking and shielding failure conditions, and determine the insulation level of the circuit breaker under lightning strikes according to the maximum overvoltage level and the insulation safety margin of the circuit breaker.

6. The circuit breaker insulation level evaluation system under lightning strikes according to claim 5, wherein, the target tower determination module includes: The first expression construction unit is used to perform simulation calculations on typical towers of different voltage levels, and establish a first quantitative function expression between the lightning withstand level of the tower under lightning back-striking and the tower height, tower grounding resistance, and tower insulation distance according to the obtained simulation calculation results; The first tower lightning withstand level determination unit is used to select the incoming line towers within the preset distance range of the substation according to the in-station equipment data, obtain the heights, grounding resistances, and insulation distances of the selected incoming line towers, and input them into the first quantitative function expression to obtain the lightning withstand levels of the selected incoming line towers under lightning back-striking.

7. The circuit breaker insulation level evaluation system under lightning strikes according to claim 6, wherein, the target tower determination module further includes: The second expression construction unit is used to perform simulation calculations on typical towers of different voltage levels, and establish a second quantitative function expression between the lightning withstand level of the tower under lightning shielding failure and the tower insulation distance according to the obtained simulation calculation results; The second tower lightning withstand level determination unit is used to obtain the insulation distances of the selected incoming line towers, and input them into the second quantitative function expression to obtain the lightning withstand levels of the selected incoming line towers under lightning shielding failure.

8. The circuit breaker insulation level evaluation system under lightning strikes according to claim 5, wherein, the insulation level determination module includes: The calculation unit is used to calculate the insulation level of the circuit breaker under lightning strikes according to the following formula: Wherein, U CB is the insulation level of the circuit breaker under lightning strike, and U max is the maximum overvoltage level, is the insulation safety margin of the circuit breaker.

9. A circuit breaker insulation level evaluation device under lightning strikes, wherein, it includes: A memory for storing instructions; wherein, the instructions are used to implement the circuit breaker insulation level evaluation method according to any one of claims 1-4; A processor for executing the instructions in the memory.

10. A computer-readable storage medium, wherein, A computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, it implements the method for evaluating the insulation level of a circuit breaker under lightning strikes as described in any one of claims 1-4.

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