A method and system for analyzing energy withstand characteristics of a resistance disc under a multi-impulse waveform

Abstract

The application discloses a kind of multi-impact waveform under resistance sheet energy tolerance characteristics analysis method and system, method includes measuring the physical size parameter of all resistance sheets of same manufacturer same model;The initial electrical performance parameter of all resistance sheets is measured, and the first resistance sheet of preselected piece number in all resistance sheets is selected;Different types of impulse current waveform are selected to carry out energy injection test on the first resistance sheet, according to the mechanical state and initial electrical performance parameter corresponding to the first resistance sheet of each impulse current waveform, failure judgment test is carried out on the first resistance sheet, and the second resistance sheet of failure is screened out from the first resistance sheet;According to the voltage waveform of both ends corresponding to the second resistance sheet of each impulse current waveform and each impulse current waveform, the energy tolerance characteristic value of each impulse current waveform is calculated, and the energy tolerance characteristics of resistance sheet under each impulse current waveform are compared and analyzed.The embodiment improves the precision of resistance sheet energy tolerance capacity evaluation, and improves the accuracy of lightning arrester selection.

Description

Technical Field

[0001] This invention relates to the field of resistive sheet withstand capability, and in particular to a method and system for analyzing the energy withstand characteristics of resistive sheets under multiple impact waveforms. Background Technology

[0002] The resistor element is a crucial component of surge arresters and a determining factor in their nonlinear UI performance. In actual operation, surge arresters may withstand various overvoltages in the system, and the waveform steepness of these overvoltages varies. For example, the wavefront steepness of a lightning impulse waveform is a few microseconds, while that of a switching overvoltage can reach hundreds of microseconds.

[0003] The energy withstand characteristics of resistor elements affect the accuracy of research results in surge arrester fault analysis, surge arrester selection, and resistor element degradation processes. Different surge arrester withstand waveforms allow for comparison of withstand values ​​to determine whether the surge arrester's withstand energy exceeds its withstand limit under overvoltage. Under different waveform overvoltages, the energy withstand value of the resistor element will vary. However, current technology lacks research on the relationship between the resistor element's energy withstand value and the waveform; often, a representative waveform, such as a square wave, is applied to the resistor element, and the obtained energy value is considered the resistor element's withstand energy. In reality, under different waveforms, especially with steep wavefronts, the energy withstand of resistor elements varies significantly. Therefore, testing and analyzing the energy withstand characteristics of resistor elements is particularly important for the high-quality development of resistor elements. Summary of the Invention

[0004] This invention provides a method and system for analyzing the energy withstand characteristics of resistors under multiple impact waveforms, enabling quantitative analysis of the energy withstand characteristics of resistors under various impact waveforms, improving the accuracy of evaluating the energy withstand capability of resistors, and improving the accuracy of surge arrester selection.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a method for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms, comprising:

[0006] The initial electrical performance parameters of all resistors of the same model from the same manufacturer were measured through the first parameter test. A preset number of resistors were selected from all the resistors to obtain the first resistor.

[0007] Energy injection tests were conducted on the first resistor by selecting different types of impact current waveforms to obtain the voltage waveform and mechanical state of the first resistor corresponding to each impact current waveform.

[0008] Based on the mechanical state and initial electrical performance parameters of the first resistor corresponding to each impact current waveform, a failure judgment test is performed on the first resistor, and the failed resistor is selected from the first resistor to obtain the second resistor for each impact current waveform.

[0009] Based on the voltage waveforms at both ends of the second resistor corresponding to each inrush current waveform and each inrush current waveform, calculate the withstand energy characteristic value of each inrush current waveform; where the withstand energy characteristic value includes the average withstand energy per unit volume and the withstand current value per unit cross-sectional area.

[0010] Based on the energy withstand characteristics of each impact current waveform, the energy withstand characteristics of the resistor under each impact current waveform are compared and analyzed.

[0011] In implementing this embodiment of the invention, the initial electrical performance parameters of all resistors of the same manufacturer and model are measured through a first parameter test. A predetermined number of resistors are selected from all resistors to obtain the first resistor. Energy injection tests are performed on the first resistor using different types of inrush current waveforms to obtain the voltage waveforms and mechanical states corresponding to each inrush current waveform. Based on the mechanical states and initial electrical performance parameters of the first resistors corresponding to each inrush current waveform, a failure judgment test is performed on the first resistors to screen out the failed resistors, thus obtaining the second resistors for each inrush current waveform. Based on the voltage waveforms corresponding to the second resistors and each inrush current waveform, the energy withstand characteristic value of each inrush current waveform is calculated. The energy withstand characteristic value includes the average energy withstand per unit volume and the current withstand per unit cross-sectional area. Based on the energy withstand characteristic values ​​of each inrush current waveform, the energy withstand characteristics of the resistors under each inrush current waveform are compared and analyzed. Through a series of experiments, the withstand energy characteristic values ​​of the impulse current waveform are calculated, enabling quantitative analysis of the energy withstand characteristics of resistors under various types of impulse waveforms. This improves the accuracy of evaluating the energy withstand capability of resistors and yields the energy withstand characteristics of resistors under different impulse current waveforms. This information is then used for surge arrester selection. For surge arresters operating under specific conditions, such as those on the outgoing line side and busbar side of a substation, the outgoing line side arresters are primarily affected by lightning overvoltages transmitted from the line, while the busbar arresters are mainly affected by switching overvoltages. Since the overvoltage conditions they withstand differ, a horizontal comparison can be made based on the energy withstand characteristics of different resistors under different impulse current waveforms. For outgoing line side arresters, resistors with better lightning impulse energy withstand capability are selected; for busbar side arresters, resistors with better switching overvoltage energy withstand capability are selected. Tests can be conducted on resistors from different manufacturers to select those with superior performance, thus improving the accuracy of surge arrester selection.

[0012] As preferred options, different types of impulse current waveforms include: 4 / 10μs high-current impulse waveform, 8 / 20μs lightning impulse current waveform, approximately sinusoidal half-wave impulse current waveform, 2ms square wave waveform, and 4ms square wave waveform.

[0013] As a preferred option, the initial electrical performance parameters of all resistors of the same model and from the same manufacturer are measured through the first parameter test, including:

[0014] Apply a DC voltage to each resistor of the same model from the same manufacturer. When the current density is 0.12mA / cm2, count the voltage across the resistor at this time to obtain the first representative voltage of each resistor.

[0015] An 8 / 20μs lightning impulse is applied to each resistor of the same model from the same manufacturer. The impulse current amplitude is the nominal discharge current. The voltage across the resistor is recorded at this time to obtain the first residual voltage of each resistor.

[0016] As a preferred approach, energy injection tests are conducted on the first resistive element using different types of inrush current waveforms to obtain the voltage waveforms and mechanical states of the first resistive element corresponding to each inrush current waveform. Specifically:

[0017] Based on the preset probability of resistor failure, select the current amplitude corresponding to each impact current waveform;

[0018] Based on each impact current waveform and the corresponding current amplitude, an impact test is performed on the first resistor to obtain the voltage waveform and mechanical state at both ends of the first resistor corresponding to each impact current waveform.

[0019] As a preferred embodiment, based on the mechanical state and initial electrical performance parameters corresponding to the first resistor element for each impact current waveform, a failure judgment test is performed on the first resistor element. Failed resistor elements are then selected from the first resistor elements to obtain the second resistor elements for each impact current waveform. Specifically:

[0020] Based on the mechanical state of the first resistor corresponding to each impact current waveform, resistors with mechanical damage are screened out to obtain the first failed resistor for each impact current waveform; among them, mechanical damage includes fragmentation, flashover and perforation.

[0021] The resistors without mechanical damage in the first resistors are selected to obtain the first normal resistors for each impact current waveform;

[0022] The first normal resistance element of each inrush current waveform is placed at room temperature, and then the second normal resistance element is obtained through the second parameter test. The current electrical performance parameters of the second normal resistance element of each inrush current waveform are measured. The current electrical performance parameters include the second representative voltage and the second residual voltage.

[0023] Based on preset conditions, the current electrical performance parameters and initial electrical performance parameters of the second normal resistor for each impact current waveform, the second failed resistor for each impact current waveform is selected.

[0024] Select 25A / cm 2The current amplitude is used to apply a 2ms square wave to the second normal resistor of each impact current waveform to obtain the third normal resistor of each impact current waveform.

[0025] The resistors with mechanical damage in the third normal resistors of each impact current waveform are screened out to obtain the third failed resistors of each impact current waveform.

[0026] Based on the first, second, and third failed resistors of each impact current waveform, the second resistor of each impact current waveform is obtained.

[0027] As a preferred option, based on preset conditions and the current and initial electrical performance parameters of the second normal resistor for each inrush current waveform, the second failed resistor for each inrush current waveform is selected, specifically as follows:

[0028] If the current electrical performance parameters and initial electrical performance parameters of the current resistor in the second normal resistor of each impact current waveform meet any preset condition, then the current resistor is judged to be in a failed state.

[0029] Based on all resistors that are in a failed state according to the second normal resistor of each impact current waveform, the second failed resistor of each impact current waveform is obtained.

[0030] The preset conditions include:

[0031] The second representative voltage of the current resistor is less than the first representative voltage by a first preset multiple;

[0032] The second representative voltage of the current resistor is greater than the first representative voltage by a second preset multiple;

[0033] The second residual voltage of the current resistor is less than the first residual voltage by a third preset multiple;

[0034] The second residual voltage of the current resistor is greater than the first residual voltage by a fourth preset multiple.

[0035] As a preferred embodiment, before measuring the initial electrical performance parameters of all resistors of the same model and from the same manufacturer through the first parameter test, the following steps are also included:

[0036] Measure the physical dimensions of all resistors of the same model from the same manufacturer; the physical dimensions include the cross-sectional area and volume of the resistor.

[0037] As a preferred embodiment, based on the voltage waveforms across the second resistor corresponding to each inrush current waveform and the inrush current waveform itself, the withstand energy characteristic value of each inrush current waveform is calculated, specifically as follows:

[0038] Based on the voltage waveforms across the second resistor corresponding to each inrush current waveform and the inrush current waveform, the withstand energy value of each second resistor for each inrush current waveform is calculated using the following formula:

[0039]

[0040] Where E is the withstand energy value of each second resistor, is the voltage across the resistor, i is the inrush current flowing through the resistor, and T is the duration of the inrush current.

[0041] Based on the withstand energy value of each second resistor in each impact current waveform, calculate the average withstand energy of each impact current waveform.

[0042] Calculate the average cross-sectional area of ​​each impact current waveform based on the cross-sectional area of ​​the second resistor in each impact current waveform.

[0043] Divide the current amplitude corresponding to each impact current waveform by the average cross-sectional area of ​​each impact current waveform to obtain the unit cross-sectional area withstand current value of each impact current waveform.

[0044] Calculate the average volume of each impact current waveform based on the volume of the second resistor in each impact current waveform.

[0045] The average withstand energy per unit volume of each impact current waveform is obtained by dividing the average withstand energy of each impact current waveform by the average volume of each impact current waveform.

[0046] By implementing the embodiments of the present invention, the average energy withstandd per unit volume and the current withstandd per unit cross-sectional area of ​​the resistor under different impulse current waveforms are quantitatively calculated. This can be used not only to understand the performance development of the resistor but also to analyze the degradation process of the resistor under different waveforms. Furthermore, it can be used in surge arrester fault analysis to determine whether the withstand energy exceeds the limit.

[0047] To address the same technical problem, this invention also provides an analysis system for the energy tolerance characteristics of a resistor under multiple impact waveforms, comprising: an electrical parameter acquisition module, an energy injection test module, a failure judgment module, a tolerance energy calculation module, and a comparative analysis module.

[0048] The electrical parameter acquisition module is used to measure the initial electrical performance parameters of all resistors of the same model from the same manufacturer through the first parameter test, and select a preset number of resistors from all resistors to obtain the first resistor.

[0049] The energy injection test module is used to select different types of impact current waveforms to perform energy injection tests on the first resistor, and obtain the voltage waveform and mechanical state of the first resistor corresponding to each impact current waveform.

[0050] The failure judgment module is used to perform failure judgment tests on the first resistor according to the mechanical state and initial electrical performance parameters corresponding to the first resistor of each impact current waveform, and to screen out the failed resistor from the first resistor to obtain the second resistor for each impact current waveform.

[0051] The withstand energy calculation module is used to calculate the withstand energy characteristic value of each impact current waveform based on the voltage waveform at both ends of the second resistor corresponding to each impact current waveform and each impact current waveform; wherein, the withstand energy characteristic value includes the average withstand energy per unit volume and the withstand current value per unit cross-sectional area;

[0052] The comparative analysis module is used to compare and analyze the energy tolerance characteristics of the resistor under various impact current waveforms based on the energy tolerance characteristic values ​​of each impact current waveform.

[0053] As a preferred option, it includes: a physical parameter acquisition module;

[0054] The physical parameter acquisition module is used to measure the physical dimensions of all resistors of the same model from the same manufacturer; the physical dimensions include the cross-sectional area and volume of the resistor. Attached Figure Description

[0055] Figure 1 : A flowchart illustrating an embodiment of the method for analyzing the energy tolerance characteristics of a resistor under multiple impact waveforms provided by the present invention;

[0056] Figure 2 : A flowchart of resistor failure judgment according to an embodiment of the method for analyzing the energy tolerance characteristics of resistors under multi-impact waveforms provided by the present invention;

[0057] Figure 3 : A comparison diagram of energy tolerance characteristics under different waveforms in an embodiment of the method for analyzing the energy tolerance characteristics of a resistor under multiple impact waveforms provided by the present invention;

[0058] Figure 4 This is a schematic diagram of an embodiment of an analysis system for the energy tolerance characteristics of a resistor under multiple impact waveforms provided by the present invention. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] Example 1

[0061] Please refer to Figure 1 This is a flowchart illustrating a method for analyzing the energy withstand characteristics of a resistor under multiple impulse waveforms, as provided in an embodiment of the present invention. This method is applicable to analyzing the energy withstand characteristics of a surge arrester resistor under different steep currents. By quantitatively analyzing the energy withstand characteristics of the resistor under various impulse waveforms, this embodiment improves the accuracy of surge arrester selection. The analysis method includes steps 101 to 106, each step as follows:

[0062] Step 101: Measure the physical dimensions of all resistors of the same manufacturer and model; the physical dimensions include the cross-sectional area and volume of the resistor.

[0063] In this embodiment, a batch of resistors of a certain model from a certain manufacturer is selected, and the physical dimensional parameters of this batch of resistors are measured. The cross-sectional area of ​​the resistor is denoted as S, and the volume is denoted as V.

[0064] Step 102: Through the first parameter test, measure the initial electrical performance parameters of all resistors of the same model from the same manufacturer, select the preset number of resistors from all resistors, and obtain the first resistor.

[0065] Optionally, the initial electrical performance parameters of all resistors of the same model and manufacturer are measured through the first parameter test, including: applying a DC voltage to each resistor of the same model and manufacturer, and when the current density is 0.12mA / cm2, the voltage across the resistor is recorded to obtain the first representative voltage of each resistor; applying an 8 / 20μs lightning impulse to each resistor of the same model and manufacturer, with the impulse current amplitude being the nominal discharge current, and recording the voltage across the resistor to obtain the first residual voltage of each resistor.

[0066] In this embodiment, the initial electrical performance parameters of the resistor are measured. These parameters are determined by selecting two characteristic parameter points on the UI characteristic curve of the resistor. During the first parameter test, the first characteristic parameter point is the representative voltage, i.e., a DC voltage is applied to the resistor. When the current density is 0.12 mA / cm², this voltage is the representative voltage, denoted by Uc, and its initial value (first representative voltage) is Uc0. The second characteristic parameter point is the residual voltage under the nominal discharge current. An 8 / 20 lightning impulse is applied to the resistor, with the impulse current amplitude being the nominal discharge current. The voltage across the resistor at this point is the residual voltage, denoted by Ur, and its initial value (first residual voltage) is Ur0. The values ​​of these two characteristic parameter points for all resistors are measured and recorded to obtain the first representative voltage Uc0 and the first residual voltage Ur0 for each resistor. Subsequently, a number of resistors, with a preset number of 20 or more, are selected as samples for the next impulse test (energy injection test).

[0067] Step 103: Select different types of impact current waveforms to conduct energy injection tests on the first resistor, and obtain the voltage waveform and mechanical state of the first resistor corresponding to each impact current waveform.

[0068] Optional types of impulse current waveforms include: 4 / 10μs high-current impulse waveform, 8 / 20μs lightning impulse current waveform, approximately sinusoidal half-wave impulse current waveform, 2ms square wave waveform, and 4ms square wave waveform.

[0069] In this embodiment, the waveform of the impact current applied to the resistor is determined. To verify the energy tolerance of the resistor under different current waveform steepness, the following five impact current waveforms with different wavefront steepness or duration are selected.

[0070] (1) 4 / 10μs high current impact;

[0071] (2) 8 / 20μs lightning impulse current;

[0072] (3) 200~230μs (approximately sinusoidal half-wave impact current with an instantaneous value exceeding 5% of the peak value and a duration of 200μs~230μs);

[0073] (4) 2ms square wave;

[0074] (5) 4ms square wave.

[0075] Optionally, step 103 specifically involves: selecting the current amplitude corresponding to each impact current waveform based on the preset probability of resistor failure; conducting one impact test on the first resistor based on each impact current waveform and the current amplitude corresponding to each impact current waveform to obtain the voltage waveform and mechanical state of the first resistor corresponding to each impact current waveform.

[0076] In this embodiment, five different impact current waveforms are subjected to the same impact test and failure judgment test to calculate the withstand energy value under different impact current waveforms. One impact test (energy injection test) is performed on the resistor element using any waveform, and the impact current waveform and the voltage waveform across the resistor element are recorded. The voltage waveform and mechanical state of the first resistor element corresponding to each impact current waveform are statistically analyzed. When selecting the current amplitude corresponding to different impact current waveforms, the probability of resistor element failure at that current amplitude is a preset probability (20%–80%), which is used to select the amplitude of each current impact waveform. Furthermore, the current amplitude will vary depending on the specifications and manufacturer of the resistor element; the current amplitude corresponding to different impact current waveforms can be selected through a large amount of experimental data.

[0077] Step 104: Based on the mechanical state and initial electrical performance parameters of the first resistor corresponding to each impact current waveform, conduct a failure judgment test on the first resistor, screen out the failed resistor from the first resistor, and obtain the second resistor for each impact current waveform.

[0078] Optionally, step 104 specifically involves: Based on the mechanical state of the first resistor corresponding to each impact current waveform, identifying resistors with mechanical damage to obtain the first failed resistors for each impact current waveform; where mechanical damage includes fragmentation, flashover, and perforation; identifying resistors without mechanical damage to obtain the first normal resistors for each impact current waveform; placing the first normal resistors of each impact current waveform at room temperature, and then obtaining the second normal resistors through a second parameter test; measuring the current electrical performance parameters of the second normal resistors for each impact current waveform; where the current electrical performance parameters include the second representative voltage and the second residual voltage; based on preset conditions, the current electrical performance parameters of the second normal resistors for each impact current waveform, and the initial electrical performance parameters, identifying the second failed resistors for each impact current waveform; selecting 25 A / cm... 2 The current amplitude is used to apply a 2ms square wave to the second normal resistor of each impact current waveform to obtain the third normal resistor of each impact current waveform; the resistor with mechanical damage is screened out from the third normal resistor of each impact current waveform to obtain the third failed resistor of each impact current waveform; based on the first failed resistor, the second failed resistor, and the third failed resistor of each impact current waveform, the second resistor of each impact current waveform is obtained.

[0079] In this embodiment, the failure judgment process of the resistor after the impact test is as follows: Figure 2As shown, first observe the condition of the resistor element. If visible mechanical damage (such as cracking, flashover, and perforation) is observed, the resistor element is considered to be faulty, and the first faulty resistor element is obtained. If the resistor element does not show mechanical damage (first normal resistor element), these first normal resistor elements are placed at room temperature, and the second normal resistor elements are obtained through the second parameter test. The representative voltage and residual voltage of the current resistor element (second normal resistor element) are measured sequentially. When performing the second parameter test, the first characteristic parameter point is the representative voltage, which is the voltage when a DC voltage is applied to the resistor element and the current density is 0.12mA / cm2. The second characteristic parameter point is the residual voltage under the nominal discharge current. An 8 / 20 lightning impulse is applied to the resistor element, and the impulse current amplitude is the nominal discharge current. The voltage across the resistor element at this time is the residual voltage. Measure and record the values ​​of the above two characteristic parameter points for all second normal resistor elements to obtain the second representative voltage Uc1 and the second residual voltage Ur1 of the second normal resistor element. If any one of the preset conditions is met, the resistor is considered to have failed, thus identifying the second failed resistor for each impact current waveform. To avoid misjudgment due to minor internal structural damage that is not visible externally, a 2ms square wave is applied to the second normal resistor after the above test, with the current amplitude selected at 25A / cm². The resistor is then observed after the test. If visible cracks, flashovers, or perforations are found, the resistor is considered to have failed, and the third failed resistor for each impact current waveform is obtained. If no mechanical damage is found, the resistor is considered to have passed all tests. The first, second, and third failed resistors for each impact current waveform are statistically analyzed to obtain the second failed resistor for each impact current waveform. The second failed resistor is selected from the first failed resistors.

[0080] Optionally, based on preset conditions and the current and initial electrical performance parameters of the second normal resistors for each inrush current waveform, the second failed resistors for each inrush current waveform are selected. Specifically, if the current and initial electrical performance parameters of the current resistor in the second normal resistors of each inrush current waveform meet any preset condition, then the current resistor is determined to be in a failed state. Based on all resistors in the second normal resistors of each inrush current waveform that are in a failed state, the second failed resistors for each inrush current waveform are obtained. The preset conditions include: the second representative voltage of the current resistor is less than the first representative voltage by a first preset multiple; the second representative voltage of the current resistor is greater than the first representative voltage by a second preset multiple; the second residual voltage of the current resistor is less than the first residual voltage by a third preset multiple; and the second residual voltage of the current resistor is greater than the first residual voltage by a fourth preset multiple.

[0081] In this embodiment, based on the second representative voltage Uc1 and the second residual voltage Ur1 of the second normal resistor, and their corresponding initial electrical performance parameters, the first representative voltage Uc0 and the first residual voltage Ur0, the resistor is considered to have failed if any one of the following preset conditions is met, wherein the first preset multiple is 0.95, the second preset multiple is 1.05, the third preset multiple is 0.95, and the fourth preset multiple is 1.05. The preset conditions are:

[0082] (1) The representative voltage of the resistor is Uc1 < 0.95Uc0 or Uc1 > 1.05Uc0;

[0083] (2) The residual voltage of the resistor is Ur1 < 0.95Ur0 or Uc1 > 1.05Ur0.

[0084] Step 105: Calculate the withstand energy characteristic value of each impact current waveform based on the voltage waveform at both ends of the second resistor corresponding to each impact current waveform and each impact current waveform; wherein, the withstand energy characteristic value includes the average withstand energy per unit volume and the withstand current value per unit cross-sectional area.

[0085] Optionally, step 105 specifically involves: calculating the withstand energy value of each second resistor for each impact current waveform based on the voltage waveform across the second resistor corresponding to each impact current waveform and the impact current waveform itself, using the following formula:

[0086]

[0087] Where E is the withstand energy value of each second resistor, is the voltage across the resistor, i is the inrush current flowing through the resistor, and T is the duration of the inrush current.

[0088] Based on the withstand energy value of each second resistor in each impact current waveform, calculate the average withstand energy of each impact current waveform; based on the cross-sectional area of ​​the second resistor in each impact current waveform, calculate the average cross-sectional area of ​​each impact current waveform; divide the current amplitude corresponding to each impact current waveform by the average cross-sectional area of ​​each impact current waveform to obtain the withstand current value per unit cross-sectional area of ​​each impact current waveform; based on the volume of the second resistor in each impact current waveform, calculate the average volume of each impact current waveform; divide the average withstand energy of each impact current waveform by the average volume of each impact current waveform to obtain the average withstand energy per unit volume of each impact current waveform.

[0089] In this embodiment, for all the resistors (second resistors) that failed during the test, based on the impact current waveform and the voltage waveform across the resistor recorded in step 103, the withstand energy value E of the resistor in the energy injection test is calculated according to the following formula:

[0090]

[0091] Where E is the withstand energy value of each second resistor element, is the voltage across the resistor element of the surge arrester, i is the impulse current flowing through the resistor element of the surge arrester, and T is the duration of the impulse current.

[0092] The energy values ​​of all failed resistors are averaged to obtain the average withstand energy E0. Then, based on the statistically analyzed cross-sectional area and volume of the resistors, the average withstand energy is divided by the average volume of each impact current waveform to calculate the average withstand energy per unit volume of the resistor E0 / V. The withstand current per unit cross-sectional area is obtained by dividing the impact current amplitude by the average cross-sectional area of ​​each impact current waveform, and the withstand current per unit cross-sectional area of ​​the resistor I / S is obtained.

[0093] Step 106: Based on the energy withstand characteristic values ​​of each impact current waveform, compare and analyze the energy withstand characteristics of the resistor under each impact current waveform.

[0094] In this embodiment, through steps 103 to 105, the average energy withstand per unit volume and the current withstand per unit cross-sectional area of ​​the resistor under all current impact waveforms are calculated. The energy withstand characteristics of the resistor under different waveforms are compared and analyzed. The energy withstand characteristics under different waveforms are compared, such as... Figure 3 As shown, S represents a 4 / 10μs high-current impulse; U represents an 8 / 20μs lightning impulse current; V represents a 200–230μs (approximately sinusoidal half-wave impulse current with an instantaneous value exceeding 5% of the peak value and a duration of 200–230μs); W represents a 2ms square wave; X represents a 4ms square wave; and Y represents the applied power frequency voltage for a duration of 10s. Figure 3 As shown, the vertical axis represents the average energy withstand per unit volume, and the horizontal axis represents the current withstand per unit cross-sectional area. This allows us to obtain the average energy withstand per unit volume for different manufacturers' specifications and models of resistors under different waveforms. The graph also reveals the specific values ​​of the resistor's withstand limits, such as the maximum current withstand per unit cross-sectional area and the maximum energy withstand per unit volume. By obtaining the withstand energy characteristic values ​​under various waveforms, we can identify the patterns in energy withstand. For the same type of resistor under different waveforms, the energy withstand value first increases and then decreases as the surge front steepness increases. These withstand energy characteristic values ​​can be applied to surge arrester fault and defect analysis. For example, if a surge arrester fault is known under a certain overvoltage waveform, we can calculate the energy absorbed and the surge current amplitude that the arrester withstands. By comparing these values ​​with the values ​​in the graph, we can determine whether the overvoltage exceeds the arrester's withstand capability or not, indicating a quality problem with the arrester. It can also be used for early warning of surge arrester status, recording the overvoltage waveforms experienced by the surge arrester during operation. If the surge arrester withstands an overvoltage amplitude or energy exceeding the value on the graph, even if the surge arrester is currently operating normally, it is considered that the surge arrester has suffered irreversible damage and should be taken out of operation immediately.

[0095] By implementing the embodiments of this invention, through a series of experiments, the withstand energy characteristic value of the impulse current waveform is calculated, realizing the quantitative analysis of the energy withstand characteristics of the resistor under various types of impulse waveforms, improving the accuracy of the evaluation of the resistor's energy withstand capability, and obtaining the energy withstand characteristics of the resistor under different impulse current waveforms. This is used for surge arrester selection. For surge arresters operating under certain conditions, such as surge arresters on the outgoing line side and busbar side of a substation, the outgoing line side surge arrester is mainly affected by lightning overvoltage transmitted from the line, while the busbar surge arrester is mainly affected by switching overvoltage. The overvoltage conditions they withstand are different. Therefore, a horizontal comparison can be made based on the energy withstand characteristics of different resistors under different impulse current waveforms. For the outgoing line side surge arrester, a resistor with better lightning impulse energy withstand capability can be selected, and for the busbar side surge arrester, a resistor with better switching overvoltage energy withstand capability can be selected. Resistors from different manufacturers can be tested to select the manufacturer with better performance, thereby improving the accuracy of surge arrester selection.

[0096] Example 2

[0097] Accordingly, see Figure 4 , Figure 4 This is a schematic diagram of a second embodiment of the analysis system for the energy tolerance characteristics of a resistive element under multiple impact waveforms provided by the present invention. Figure 4 As shown, the analysis system for the energy tolerance characteristics of a resistor under multiple impact waveforms includes a physical parameter acquisition module 401, an electrical parameter acquisition module 402, an energy injection test module 403, a failure judgment module 404, a tolerance energy calculation module 405, and a comparative analysis module 406.

[0098] The physical parameter acquisition module 401 is used to measure the physical dimensional parameters of all resistors of the same model from the same manufacturer; the physical dimensional parameters include the cross-sectional area and volume of the resistor.

[0099] The electrical parameter acquisition module 402 is used to measure the initial electrical performance parameters of all resistors of the same model and from the same manufacturer through the first parameter test, and select a preset number of resistors from all resistors to obtain the first resistor.

[0100] The energy injection test module 403 is used to select different types of impact current waveforms to perform energy injection tests on the first resistor, and obtain the voltage waveform and mechanical state of the first resistor corresponding to each impact current waveform.

[0101] The failure judgment module 404 is used to perform a failure judgment test on the first resistor according to the mechanical state and initial electrical performance parameters corresponding to the first resistor of each impact current waveform, and to screen out the failed resistor from the first resistor to obtain the second resistor of each impact current waveform.

[0102] The withstand energy calculation module 405 is used to calculate the withstand energy characteristic value of each impact current waveform based on the voltage waveform at both ends of the second resistor corresponding to each impact current waveform and each impact current waveform; wherein, the withstand energy characteristic value includes the average withstand energy per unit volume and the withstand current value per unit cross-sectional area.

[0103] The comparative analysis module 406 is used to compare and analyze the energy tolerance characteristics of the resistor under each impact current waveform based on the energy tolerance characteristic value of each impact current waveform.

[0104] By implementing the embodiments of this invention, the energy withstand characteristics of the resistor element under different impulse current waveforms are obtained, which can be used to understand the performance development of the resistor element. It can be used to analyze the degradation process of the resistor element under different waveforms. It can be used in surge arrester fault analysis to determine whether the withstand energy exceeds the limit. It can be used for surge arrester selection. For surge arresters operating under certain conditions, such as surge arresters on the outgoing line side and busbar side of a substation, the outgoing line side surge arrester is mainly affected by lightning overvoltage transmitted from the line, while the busbar surge arrester is mainly affected by switching overvoltage. Because the overvoltage conditions they withstand are different, this patented invention can be used to select resistor elements with better lightning impulse energy withstand capability for the outgoing line side surge arrester and resistor elements with better switching overvoltage energy withstand capability for the busbar side surge arrester. It can also be used to test resistors from different manufacturers and select the one with superior performance.

[0105] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms, characterized in that, include: The initial electrical performance parameters of all resistors of the same model and from the same manufacturer are measured through the first parameter test. A preset number of resistors are selected from all the resistors to obtain the first resistor. Energy injection tests were conducted on the first resistor by selecting different types of impact current waveforms to obtain the voltage waveforms and mechanical states of the first resistor corresponding to each impact current waveform. Based on the mechanical state and initial electrical performance parameters corresponding to the first resistor corresponding to each of the aforementioned impact current waveforms, a failure judgment test is performed on the first resistor, and the failed resistor is selected from the first resistor to obtain the second resistor for each of the aforementioned impact current waveforms. Based on the voltage waveforms at both ends of the second resistor corresponding to each of the said impact current waveforms and each of the said impact current waveforms, the withstand energy characteristic value of each of the said impact current waveforms is calculated; wherein, the withstand energy characteristic value includes the average withstand energy per unit volume and the withstand current value per unit cross-sectional area; Based on the energy tolerance characteristic values ​​of each of the aforementioned impact current waveforms, the energy tolerance characteristics of the resistor under each of the aforementioned impact current waveforms are compared and analyzed.

2. The method for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms as described in claim 1, characterized in that, The different types of impulse current waveforms include: 4 / 10μs large current impulse waveform, 8 / 20μs lightning impulse current waveform, approximately sinusoidal half-wave impulse current waveform, 2ms square wave waveform, and 4ms square wave waveform.

3. The method for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms as described in claim 1, characterized in that, The first parameter test measures the initial electrical performance parameters of all resistors of the same model and from the same manufacturer, including: Apply a DC voltage to each of the resistors of the same model from the same manufacturer. When the current density is 0.12mA / cm2, count the voltage across the resistor at this time to obtain the first representative voltage of each resistor. An 8 / 20μs lightning impulse is applied to each of the resistors of the same manufacturer and model. The impulse current amplitude is the nominal discharge current. The voltage across the resistor is recorded at this time to obtain the first residual voltage of each resistor.

4. The method for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms as described in claim 1, characterized in that, The process involves selecting different types of impact current waveforms to perform energy injection tests on the first resistor, obtaining the voltage waveform and mechanical state of the first resistor corresponding to each impact current waveform, specifically as follows: Based on the preset probability of resistor failure, the current amplitude corresponding to each of the aforementioned impact current waveforms is selected; Based on each of the said impact current waveforms and the current amplitude corresponding to each of the said impact current waveforms, the first resistor is subjected to one impact test to obtain the voltage waveform and mechanical state of the first resistor corresponding to each of the said impact current waveforms.

5. The method for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms as described in claim 3, characterized in that, The step of performing a failure judgment test on the first resistor based on the mechanical state and initial electrical performance parameters corresponding to each of the aforementioned impact current waveforms, and selecting the failed resistors from the first resistors to obtain the second resistors for each of the aforementioned impact current waveforms, specifically involves: Based on the mechanical state corresponding to the first resistor in each of the said impact current waveforms, resistors with mechanical damage are screened out to obtain the first failed resistors for each of the said impact current waveforms; wherein, the mechanical damage includes fragmentation, flashover and perforation; The resistors without mechanical damage in the first resistors are selected to obtain the first normal resistors for each of the said impact current waveforms; The first normal resistance element of each of the aforementioned impulse current waveforms is placed at room temperature, and then a second normal resistance element is obtained through a second parameter test. The current electrical performance parameters of the second normal resistance element of each of the aforementioned impulse current waveforms are measured; wherein, the current electrical performance parameters include a second representative voltage and a second residual voltage. Based on preset conditions, the current electrical performance parameters and the initial electrical performance parameters of the second normal resistor for each of the aforementioned impact current waveforms, the second failed resistor for each of the aforementioned impact current waveforms is selected. Select 25A / cm 2 The current amplitude is used to apply a 2ms square wave to the second normal resistor of each of the said impact current waveforms to obtain the third normal resistor of each of the said impact current waveforms. By screening out the resistors with mechanical damage among the third normal resistors of each of the aforementioned impact current waveforms, the third failed resistors of each of the aforementioned impact current waveforms are obtained. The second resistor for each of the aforementioned impact current waveforms is obtained based on the first, second, and third failed resistors.

6. The method for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms as described in claim 5, characterized in that, The step of selecting the second failed resistor for each of the following impact current waveforms based on preset conditions, the current electrical performance parameters of the second normal resistor for each of the aforementioned impact current waveforms, and the initial electrical performance parameters, specifically involves: If the current electrical performance parameter and the initial electrical performance parameter of the current resistor in the second normal resistor of each of the said impact current waveforms satisfy any of the preset conditions, then the current resistor is determined to be in a failed state; Based on all the resistors that are in the failed state according to the second normal resistor of each of the said impact current waveforms, the second failed resistor of each of the said impact current waveforms is obtained. The preset conditions include: The second representative voltage of the current resistor is less than the first representative voltage by a first preset multiple; The second representative voltage of the current resistor is greater than the first representative voltage by a second preset multiple; The second residual voltage of the current resistor is less than the first residual voltage by a third preset multiple; The second residual voltage of the current resistor is greater than the first residual voltage by a fourth preset multiple.

7. The method for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms as described in claim 4, characterized in that, Before measuring the initial electrical performance parameters of all resistors of the same model and from the same manufacturer through the first parameter test, the following steps are also included: Measure the physical dimensions of all resistors of the same manufacturer and model; wherein, the physical dimensions include the cross-sectional area and volume of the resistor.

8. The method for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms as described in claim 7, characterized in that, The step of calculating the withstand energy characteristic value of each impact current waveform based on the voltage waveform across the second resistor corresponding to each impact current waveform and each impact current waveform is as follows: Based on the voltage waveforms across the second resistor corresponding to each of the aforementioned inrush current waveforms and the respective inrush current waveforms, the withstand energy value of each second resistor for each of the aforementioned inrush current waveforms is calculated using the following formula: Where E is the energy withstand value of each second resistor, is the voltage across the resistor, i is the inrush current flowing through the resistor, and T is the duration of the inrush current. The average withstand energy of each of the second resistors in each of the aforementioned impact current waveforms is calculated based on the withstand energy value of each of the second resistors in each of the aforementioned impact current waveforms. The average cross-sectional area of ​​each of the said impact current waveforms is calculated based on the cross-sectional area of ​​the second resistor in each of the said impact current waveforms. Divide the current amplitude corresponding to each of the aforementioned impact current waveforms by the average cross-sectional area of ​​each of the aforementioned impact current waveforms to obtain the unit cross-sectional area withstand current value of each of the aforementioned impact current waveforms. The average volume of each of the said impact current waveforms is calculated based on the volume of the second resistor in each of the said impact current waveforms. The average withstand energy of each of the aforementioned impact current waveforms is divided by the average volume of each of the aforementioned impact current waveforms to obtain the average withstand energy per unit volume of each of the aforementioned impact current waveforms.

9. A system for analyzing the energy tolerance characteristics of a resistive element under multiple impact waveforms, characterized in that, include: The module includes an electrical parameter acquisition module, an energy injection test module, a failure judgment module, a withstand energy calculation module, and a comparative analysis module. The electrical parameter acquisition module is used to measure the initial electrical performance parameters of all resistors of the same model and from the same manufacturer through a first parameter test, and select a preset number of resistors from all resistors to obtain the first resistor. The energy injection test module is used to select different types of impact current waveforms to perform energy injection tests on the first resistor, and obtain the voltage waveform and mechanical state of the first resistor corresponding to each impact current waveform. The failure judgment module is used to perform a failure judgment test on the first resistor according to the mechanical state and the initial electrical performance parameters corresponding to the first resistor of each impact current waveform, and to screen out the failed resistor from the first resistor to obtain the second resistor for each impact current waveform. The withstand energy calculation module is used to calculate the withstand energy characteristic value of each of the impact current waveforms based on the voltage waveforms at both ends of the second resistor corresponding to each of the impact current waveforms and each of the impact current waveforms; wherein, the withstand energy characteristic value includes the average withstand energy per unit volume and the withstand current value per unit cross-sectional area; The comparative analysis module is used to compare and analyze the energy tolerance characteristics of the resistor under each of the said impact current waveforms based on the energy tolerance characteristic values ​​of each of the said impact current waveforms.

10. The analysis system for the energy tolerance characteristics of a resistive element under multiple impact waveforms as described in claim 9, characterized in that, include: Physical parameter acquisition module; The physical parameter acquisition module is used to measure the physical dimensional parameters of all resistors of the same manufacturer and model; wherein the physical dimensional parameters include the cross-sectional area and volume of the resistor.

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