A method for analyzing the extent of damage to internal strands of a fitting and related devices

Abstract

The application discloses a kind of hardware internal strand damage degree analysis method and related device, 1) by comparing the numerical relationship between the strand mechanical properties and actual stress under different temperatures, determine the strand characteristic temperature corresponding to different damage degree, according to the characteristic temperature of strand body, corresponding hardware surface temperature is calculated by combining finite element simulation method, so as to determine the temperature sensing threshold of detection device;2) the relationship between the minimum breaking force of strand under different temperatures and the maximum allowable axial tension of line is used as the basis for judgment, and the characteristic temperature of different strand breaking degree of line is found out;3) determine that the heat of short-time thermal defect comes from the contact resistance joule heat of the contact position of hardware and line, arc heat of breakdown discharge, and the breaking sequence is from the strand closest to hardware, from outside to inside.Solve the problem that prior art cannot judge the damage degree of internal strand of hardware and the accuracy is poor when judging the local defect of internal strand of hardware at fixed point.

Description

Technical Field

[0001] This application relates to the field of power cable condition analysis technology, and in particular to a method and related apparatus for analyzing the degree of damage to internal strands of fittings. Background Technology

[0002] Overhead transmission lines are suspended from towers via splicing and connecting fittings. Due to contamination of the internal contact surfaces of these fittings and electrochemical corrosion of copper and aluminum, contact resistance is high. Abnormal current flow or poor contact conditions can easily cause localized overheating at the connection points, leading to thermal defects in the transmission line. These thermal defects can easily cause damage to conductors and ground wires, resulting in broken strands. For detecting thermal defects in transmission lines, power grid maintenance departments primarily use drone infrared line inspections and manual inspections. However, current drone infrared thermography and manual inspection methods rely on periodic inspections and cannot provide real-time, long-term online monitoring of thermal defects in transmission lines.

[0003] To achieve comprehensive detection of thermal defects in power lines and identify potential safety risks in overhead transmission lines, it is necessary to develop a detection device for short-term thermal defects inside fittings. This device should be able to sense short-term high temperatures within the fittings and assess the degree of damage to the conductors under these conditions. Currently, there are thermal defect temperature-sensing detection products used in fittings such as transmission bolts and suspension clamps. However, the sensing action values ​​of these products are determined according to traditional regulations for thermal defects in transmission lines. They can only respond to the thermal defect temperatures defined in these regulations and cannot detect the degree of damage to the conductors caused by thermal defects. Furthermore, existing conductor damage detection methods are mainly vibration detection methods, relying on the mechanical properties of the line itself to achieve the detection function. These methods are mainly used to detect mechanical damage to the line itself over one or more spans, and cannot accurately capture the specific location of damage to the conductors, nor can they be applied to damage detection inside fittings with complex mechanical conditions. Summary of the Invention

[0004] This application provides a method and related apparatus for analyzing the degree of damage to the internal strands of fittings, which solves the technical problems of existing technologies being unable to determine the degree of damage to the internal strands of fittings, unable to pinpoint the local defects of the internal strands of fittings, and having poor accuracy.

[0005] In view of this, the first aspect of this application provides a method for analyzing the degree of damage to internal wire strands in hardware, the method comprising:

[0006] S1. Calculate the minimum breaking force F of the entire circuit containing n strands and a single strand under normal temperature and conditions. A and F a Based on minimum breaking force F A and F aCalculate the total number of broken strands m in the entire line, and calculate the maximum allowable average force F on a single strand. b(m) ;

[0007] S2, Calculate the tensile strength R of the wire strand at temperature T. T Therefore, the minimum breaking force F of a single strand at temperature T can be calculated. a,T ;

[0008] S3, regarding the maximum permissible average force F b(m) and minimum breaking force F a,T Comparative analysis shows that when the minimum breaking force F a,T Greater than the maximum allowable average force F b(m) Then, after adjusting the temperature T, return to step S2. When the minimum breaking force F... a,T Not greater than the maximum permissible average force F b(m) If the wire strand is determined to be in a broken state, then temperature T is taken as the characteristic temperature T. c(m) ;

[0009] S4. Mark the location of the broken strands according to the number of broken strands m; establish a local geometric model of the line-fitting system, set a short-time excitation I(t) as input to the finite element simulation model, and obtain the average temperature T of the line cross section where the marked broken strand m is located. avr(m) ;

[0010] S5, Compare the average temperature T of the cross-section of the strands avr(m) and characteristic temperature T c(m) When the average temperature of the cross section of the wire strand T avr(m) Less than the characteristic temperature T c(m) Then, after readjusting the short-time excitation I(t), return to step S4 for simulation calculation. When the average temperature T of the wire strand cross section... avr(m) Not less than the characteristic temperature T c(m) Then we obtain the characteristic excitation I. m (t), and calculate the temperature sensing threshold T of the detection device. m ;

[0011] S6, Output the number of broken shares m, Feature stimulus I m (t) and the temperature threshold T of the detection device m .

[0012] Optionally, the calculation includes the minimum breaking force F of the entire circuit with n strands and a single strand under normal temperature and conditions. A and F a Based on minimum breaking force F A and F a Calculate the total number of broken strands m in the entire line, and calculate the maximum allowable average force F on a single strand. b(m) Specifically, it includes:

[0013] Calculate the minimum breaking force F of a circuit consisting of n strands and a single strand under normal temperature and conditions. A and F a Based on the minimum breaking force F of the entire line A Calculate the maximum allowable axial tensile force F of the entire line. B Based on the maximum permissible axial tensile force F of the entire line B Calculate the maximum allowable number of broken strands N in the circuit;

[0014] The total number of strand breaks, m, is determined based on the maximum permissible number of strand breaks, N; and based on the number of strand breaks, m, and the maximum permissible axial tensile force, F... B Calculate the maximum permissible average force F on a single strand. b(m) .

[0015] Optionally, the tensile strength R of the strand corresponding to the calculated temperature T T Therefore, the minimum breaking force F of a single strand at temperature T can be calculated. a,T Specifically, it includes:

[0016] Calculate the tensile strength R of the strand at temperature T based on the reduction factor. T According to the tensile strength R of the strand T Calculate the minimum breaking force F of a single strand at temperature T by considering the cross-sectional area and number of strands. a,T .

[0017] Optionally, marking the location of the broken share according to the number of broken shares m specifically includes:

[0018] Assumptions: The temperature characteristics of short-term thermal defects in the circuit start with the strand closest to the fitting, with the temperature of the strand closer to the fitting contact surface being higher, the temperature of the strand closer to the middle being lower, and the temperature of the very center strand being the lowest; and under the condition of short-term thermal defects, the order of strand breakage in the circuit starts from the outermost strand closest to the fitting, with the breakage occurring later as the strands move closer to the center, and the very center strand breaking last.

[0019] Then: Based on the above assumptions, and by marking the location of the broken shares according to the number of broken shares m, we obtain the broken share m.

[0020] A second aspect of this application provides a system for analyzing the degree of damage to internal wire strands in hardware, the system comprising:

[0021] The first calculation unit is used to calculate the minimum breaking force F of the entire circuit containing n strands and a single strand under normal temperature and conditions. A and F a Based on minimum breaking force F A and F a Calculate the total number of broken strands m in the entire line, and calculate the maximum allowable average force F on a single strand.b(m) ;

[0022] The second calculation unit is used to calculate the tensile strength R of the strand at temperature T. T Therefore, the minimum breaking force F of a single strand at temperature T can be calculated. a,T ;

[0023] The first analysis unit is used to analyze the maximum permissible average force F. b(m) and minimum breaking force F a,T Comparative analysis shows that when the minimum breaking force F a,T Greater than the maximum allowable average force F b(m) Then, after adjusting the temperature T, the second calculation unit is triggered, and the minimum breaking force F... a,T Not greater than the maximum permissible average force F b(m) If the wire strand is determined to be in a broken state, then temperature T is taken as the characteristic temperature T. c(m) ;

[0024] The third calculation unit is used to mark the location of the broken strands according to the number of broken strands m; and to establish a local geometric model of the line-fitting system, set a short-time excitation I(t) as input to the finite element simulation model to calculate the average temperature T of the cross section of the marked broken strand m. avr(m) ;

[0025] The second analysis unit is used to compare the average temperature T of the strand cross-section. avr(m) and characteristic temperature T c(m) When the average temperature of the cross section of the wire strand T avr(m) Less than the characteristic temperature T c(m) Then, after readjusting the short-time excitation I(t), the third calculation unit is triggered to perform simulation calculations. When the average temperature T of the strand cross section... avr(m) Not less than the characteristic temperature T c(m) Then we obtain the characteristic excitation I. m (t), and calculate the temperature sensing threshold T of the detection device. m ;

[0026] Output unit, used to output the number of broken shares m and the characteristic excitation I. m (t) and the temperature threshold T of the detection device m .

[0027] Optionally, the first computing unit is specifically used for:

[0028] Calculate the minimum breaking force F of a circuit consisting of n strands and a single strand under normal temperature and conditions. A and F a Based on the minimum breaking force F of the entire line A Calculate the maximum allowable axial tensile force F of the entire line. B Based on the maximum permissible axial tensile force F of the entire lineB Calculate the maximum allowable number of broken strands N in the circuit;

[0029] The total number of strand breaks, m, is determined based on the maximum permissible number of strand breaks, N; and based on the number of strand breaks, m, and the maximum permissible axial tensile force, F... B Calculate the maximum permissible average force F on a single strand. b(m) .

[0030] Optionally, the second computing unit is specifically used for:

[0031] Calculate the tensile strength R of the strand at temperature T based on the reduction factor. T According to the tensile strength R of the strand T Calculate the minimum breaking force F of a single strand at temperature T by considering the cross-sectional area and number of strands. a,T .

[0032] Optionally, marking the location of the broken share according to the number of broken shares m specifically includes:

[0033] Assumptions: The temperature characteristics of short-term thermal defects in the circuit start with the strand closest to the fitting, with the temperature of the strand closer to the fitting contact surface being higher, the temperature of the strand closer to the middle being lower, and the temperature of the very center strand being the lowest; and under the condition of short-term thermal defects, the order of strand breakage in the circuit starts from the outermost strand closest to the fitting, with the breakage occurring later as the strands move closer to the center, and the very center strand breaking last.

[0034] Then: Based on the above assumptions, and by marking the location of the broken shares according to the number of broken shares m, we obtain the broken share m.

[0035] A third aspect of this application provides a device for analyzing the degree of damage to internal wire strands in hardware, the device comprising a processor and a memory:

[0036] The memory is used to store program code and transmit the program code to the processor;

[0037] The processor is used to execute the steps of the method for analyzing the degree of damage to internal wire strands of hardware as described in the first aspect above, according to the instructions in the program code.

[0038] The fourth aspect of this application provides a computer-readable storage medium for storing program code for executing the method for analyzing the degree of damage to internal wire strands in hardware as described in the first aspect above.

[0039] As can be seen from the above technical solutions, this application has the following advantages:

[0040] 1. By studying the intrinsic relationship between the internal temperature of the wire strands in fittings and the degree of damage, the temperature characteristics exhibited by different damage types of different wire types can be obtained, enabling the judgment of the damage state of the wire strands inside the fittings, and simultaneously issuing warning signals in subsequent products. Through mutual verification of theoretical calculations and simulation results, the degree of damage occurring inside the wire strands at a certain characteristic temperature for different wire types can be accurately determined.

[0041] 2. The method protected by this invention targets internal wire strand defects in fittings caused by heat generation on the circuit. By analyzing the wire strand heating temperature, mechanical properties, and stress conditions on the circuit, the corresponding relationship between the degree of wire strand damage and surface temperature at a specific location inside the fitting can be obtained. This allows for the design of corresponding temperature sensing devices that can detect short-term, precise thermal defects at specific points by acting on this characteristic temperature.

[0042] 3. The simulation technology used in this method only requires applying excitation to a local location of the hardware and performing simulation simultaneously. Compared with the existing full-process simulation analysis method for thermal defects, the simulation method has lower computing power requirements and higher simulation efficiency and accuracy. From an economic perspective, only an ordinary computer is needed to complete the simulation steps, without the need for expensive workstations for calculation. Attached Figure Description

[0043] Figure 1 This is a flowchart illustrating an embodiment of a method for analyzing the degree of damage to internal wire strands in hardware provided in this application.

[0044] Figure 2 This is a schematic diagram of the structure of an embodiment of a hardware internal strand damage analysis system provided in this application.

[0045] Figure 3 This is a schematic diagram of a single-strand wire fracture analysis process provided in an embodiment of this application;

[0046] Figure 4 This is a schematic diagram of a fracture analysis process for m strands provided in an embodiment of this application;

[0047] Figure 5 This is a schematic diagram of a finite element simulation setup provided in the embodiments of this application;

[0048] Figure 6 This is a schematic diagram illustrating the numbering sequence of broken strands in a circuit according to an embodiment of this application. Detailed Implementation

[0049] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0050] It should be noted that:

[0051] This embodiment makes the following assumptions:

[0052] 1. Assume that each strand of wire is subjected to uniform force;

[0053] 2. Assume that the temperature characteristic of short-term thermal defects in the circuit starts from the strand closest to the fitting, with the temperature of the strand closer to the fitting contact surface being higher, the temperature of the strand closer to the middle being lower, and the temperature of the strand in the very center being the lowest.

[0054] 3. According to hypothesis 2, in the case of short-term thermal defects, the strand breakage sequence starts from the outermost strand closest to the fitting, and the closer to the center, the later the strand breaks, with the innermost strand breaking last.

[0055] 4. In the case of multiple strands breaking due to short-term thermal defects, it is assumed that only one strand can break at a certain moment, and multiple strands cannot break at the same time. There is a time difference between the breakage of strands at different locations.

[0056] Please see Figure 1 The present application provides a method for analyzing the degree of damage to internal wire strands in hardware, comprising:

[0057] Step 101: Calculate the minimum breaking force F of the entire circuit containing n strands and a single strand under normal temperature and conditions. A and F a Based on minimum breaking force F A and F a Calculate the total number of broken strands m in the entire line, and calculate the maximum allowable average force F on a single strand. b(m) ;

[0058] Specifically, this includes:

[0059] Step 1011: Based on relevant regulations and material parameters, calculate the minimum breaking force F of the entire circuit containing n strands and the minimum breaking force F of each individual strand under normal temperature and conditions. A F a .

[0060] F A =R 20℃ ×S 截面 (1)

[0061]

[0062] Step 1012: Calculate the maximum allowable axial tensile force FB of the entire line. Usually, FB is taken as 0.25 times FA.

[0063] F B =0.25F A

[0064] Step 1013: Calculate the maximum allowable number of strands N to break, i.e., the minimum breaking force (nN) F of the remaining strands nN. a It just meets the maximum allowable axial tensile force F of the entire line. B .

[0065]

[0066] Step 1014: Determine the number of broken strands m in this calculation. If m is greater than N, the line has been broken at room temperature, and the calculation ends. If m is less than N, continue the calculation.

[0067] Step 1015: Calculate the maximum allowable average force F on a single strand. b(m) .

[0068]

[0069] Step 102: Calculate the tensile strength R of the wire strand corresponding to temperature T. T Therefore, the minimum breaking force F of a single strand at temperature T can be calculated. a,T ;

[0070] Specifically, this includes:

[0071] Calculate the tensile strength R of the wire strand at temperature T. T Therefore, the minimum breaking force F of a single strand at this time can be calculated. a,T As the line temperature increases, the tensile strength R of the line decreases. T Gradually decreasing, using a reduction factor k RT Perform the calculation:

[0072] R T =k RT ×R 20℃

[0073]

[0074] Step 103: For the maximum permissible average force F... b(m) and minimum breaking force F a,T Comparative analysis shows that when the minimum breaking force F a,T Greater than the maximum allowable average force F b(m)Then, after adjusting the temperature T, return to step S2. When the minimum breaking force Fa,T is not greater than the maximum allowable average force F... b(m) If the wire strand is determined to be in a broken state, then temperature T is taken as the characteristic temperature T. c(m) ;

[0075] Specifically, including:

[0076] Compare the minimum break of a single stock line (F) a,T Average force F of a single line stock b(m) The size relationship, if F a,T Greater than F b(m) Then return to step 102, increase the temperature T and continue the calculation and comparison; if F a,T Less than or equal to F b(m) If the strands are considered to be likely to break, then the characteristic temperature T is obtained. c(m) .

[0077] Step 104: Mark the location of the broken strands according to the number of broken strands m; establish a local geometric model of the line-fitting system, set a short-time excitation I(t) and input it into the finite element simulation model to calculate the average temperature T of the line section where the marked broken strand m is located. avr(m) ;

[0078] Specifically, including:

[0079] Step 1041: Based on assumptions 2 and 3, label the location of the broken strand m;

[0080] Step 1042: Establish the local geometric I(t) model of the circuit-fitting system;

[0081] Step 1043: Set the short-time excitation I(t) and input it into the finite element simulation model (using I as the input). m-1 (t is the initial value), calculate the electromagnetic heat of the model, and obtain the average temperature T of the cross section of the marked broken strand m. avr(m) ;

[0082] Step 105: Compare the average temperature T of the cross-section of the strands. avr(m) and characteristic temperature T c(m) When the average temperature of the cross section of the wire strand T avr(m) Less than the characteristic temperature T c(m) Then, after readjusting the short-time excitation I(t), return to step S4 for simulation calculation. When the average temperature T of the wire strand cross section... avr(m) Not less than the characteristic temperature T c(m) Then we obtain the characteristic excitation I. m (t), and calculate the temperature sensing threshold T of the detection device. m ;

[0083] Specifically, including:

[0084] Step 1051: Set the short-time excitation I(t) and input it into the finite element simulation model (using I as the input). m-1 (t is the initial value), calculate the electromagnetic heat of the model, and obtain the average temperature T of the cross section of the marked broken strand m. avr(m) ;

[0085] Step 1052: Compare the average temperature T of the cross section of the marked broken strand m. avr(m) and characteristic temperature T c(m) If the average temperature T of the cross section of the wire strand avr(m) Less than the characteristic temperature T c(m) Then return to step 1052 and reset the short-time excitation I(t) for calculation; if the average temperature T of the strand cross section avr(m) Greater than or equal to the characteristic temperature T c(m) Then retain the model and obtain the feature activation I. m (t), and calculate the surface temperature Tm of the hardware at this time, which is the temperature sensing threshold T of the detection device. m ;

[0086] Step 106: Output the number of broken shares m and the feature excitation I. m (t) and the temperature threshold T of the detection device m .

[0087] Finally, output the number of broken shares m and the characteristic incentive I. m (t) and the corresponding temperature threshold T of the detection device m Calculation complete.

[0088] It should be noted that, for the above steps, a classification discussion method can be used in actual operation to classify and discuss the cases with damage levels of N, 1, and m, thereby simplifying the calculation steps. Figure 3 and Figure 4 Flowcharts are provided for determining the characteristic temperature of 1 and m strands of broken wire and the temperature sensing threshold of fittings, respectively.

[0089] The following calculation example uses GJ-50 galvanized steel strand, explaining the process in three cases: N, 1, and m. Please refer to [link / reference]. Figure 5 and Figure 6 :

[0090] 1. If the number of broken strands exceeds N, the remaining unbroken strands are insufficient to withstand the maximum axial tensile force allowed on the line at room temperature, and the line may break at room temperature:

[0091] The first step is to find and calculate the structural parameters, tensile strength, and maximum allowable axial tensile force of the corresponding overall line type and its individual strands.

[0092] According to the "Design Manual for High-Voltage Transmission Lines in Power Engineering (Second Edition)" and "Steel Strand for Prestressed Concrete" (GB / T5224-2014), the structure of galvanized steel strand GJ-50 is 7 / 3 (7 strands wound, 3 mm diameter per strand), with a cross-sectional area of ​​approximately 49.50 mm², and a nominal tensile strength of 1270 MPa (20℃). Multiplying the cross-sectional area by the tensile strength yields the minimum breaking force of the entire line at room temperature, which is 63500 N; for a single strand, the minimum breaking force at room temperature is 9071 N.

[0093] The second step is to calculate the maximum axial tensile force that the line can withstand under actual operating conditions.

[0094] In actual engineering, according to the design specifications for overhead lines, the maximum permissible axial tensile force that stranded wire can withstand is the minimum breaking force multiplied by a safety factor of 0.25, which is 15875N.

[0095] The third step is to calculate the maximum number of broken strands N in the circuit under normal temperature and conditions.

[0096] Since the maximum permissible axial tensile force on the line is 15875N, which does not exceed the minimum breaking force of two strands, the line can be prevented from breaking as long as two strands remain undamaged, i.e., N=5.

[0097] 2. Only one strand of the entire line is broken, and the line will not break or disconnect under normal operating conditions:

[0098] The first step is to calculate the maximum permissible axial tensile force on a single strand.

[0099] Calculations based on the broken N strands show that the maximum permissible axial tensile force on the entire line is 15875N. Since the structure of galvanized steel strand GJ-50 is 7 / 3, based on the actual operation of the line and the average stress on the strands, the maximum permissible axial tensile force on a single strand is 2267.9N.

[0100] The second step is to find the characteristic temperature T corresponding to the break in a single stock line. c(1) .

[0101] Based on the existing temperature-tensile strength correlation, calculate the tensile strength and upper limit of tensile force (i.e., minimum breaking force) of a single strand at different temperatures. Compare these values ​​to find the temperature T (°C) corresponding to a minimum breaking force of 2267.9 N or less for a single strand, and denote this temperature T (°C) as the characteristic temperature T. c(1) .

[0102] The following is the temperature-tensile strength correlation used in this example:

[0103] R T =kRT ×R 20℃

[0104] k RT = -4.103 × 10 -14 ×θ 5 +8.160×10 -11 ×θ 4 -4.936×10 -8 ×θ 3 +7.364×10 -6 ×θ 2 -5.018×10 -4 ×θ+1.005

[0105] When the temperature of a single strand rises above 510℃, considering the reduction factor of tensile strength with temperature, the tensile strength of the strand will decrease to 0.23 times its original value, which is only 29.21 MPa. At this point, the maximum tensile force that a single strand can withstand has decreased to 2086.4 N. This value exceeds the maximum permissible axial tensile force that the stranded wire can withstand. This means that in some areas of actual power transmission networks, or under extreme weather conditions, a high temperature of 510℃ is very likely to cause a single strand to break due to tensile force. Therefore, the condition that "the average temperature of a certain cross-sectional area of ​​a single strand exceeds 510℃ and lasts for 1 second or more" can be used as a criterion for judging whether a strand of GJ-50 galvanized steel strand may break.

[0106] The third step is to establish a simulation model, calculate the average temperature of the wire cross-section, and obtain the corresponding temperature sensing threshold of the device.

[0107] A local geometric model of the circuit and fittings is established. In the finite element simulation model with short-time excitation input, the electromagnetic and thermal properties of the model are calculated through the coupling relationship between the current and temperature fields. Since temperature is transferred from the outside in, the first strand to break should be the outermost strand closest to the fitting excitation input position. The average temperature of the strand cross-section is observed; if it reaches the characteristic temperature T... c(1) If the wire strand is considered broken, the excitation input to the model at this time is recorded as the feature excitation I1(t), and the corresponding surface temperature of the fitting is recorded as the temperature sensing threshold T1 of the detection device.

[0108] 3. The entire line has a total of m broken strands, where m is between 1 and N. The line will not break or disconnect under normal operating conditions.

[0109] First, the maximum permissible axial tensile force on the entire strand is 15875N. When calculating the breakage of strand m, we assume that strand m-1 has already broken. Since the insulation of the strand is suspended, the external physical conditions will not change. Therefore, the maximum permissible axial tensile force on the remaining strand as a whole remains unchanged. Thus, the maximum permissible axial tensile force on the remaining single strand is calculated as follows:

[0110]

[0111] The second step is to calculate the tensile strength RT of the strand at temperature T based on the given temperature-tensile strength correlation, and then calculate the minimum breaking force F of a single strand at this temperature. a,T Compare F a,T , and F b(m) If F a,T less than or equal to F b(m) It is assumed that the strand breaks, and the temperature T at this point is denoted as the characteristic temperature T. c(m) Based on assumptions 2 and 3, the broken strand of the m-th strand is labeled.

[0112] The third step is to establish a simulation model of the circuit and fittings, set a short-time excitation input into the finite element simulation model, calculate the electromagnetic heat of the model, and observe the average temperature of the wire strand cross-section. If the characteristic temperature T is reached... c(1) If the line is considered broken, then the excitation input to the model at this point is recorded as the feature excitation I. m (t), and record the corresponding surface temperature of the hardware as the temperature sensing threshold Tm of the detection device.

[0113] This application provides a method for analyzing the degree of damage to internal wire strands in fittings: 1) By comparing the numerical relationship between the mechanical properties of the wire strands at different temperatures and the actual stress, the characteristic temperature of the wire strands corresponding to different degrees of damage is determined. Based on the characteristic temperature of the wire strand body, the corresponding surface temperature of the fitting is calculated using the finite element simulation method, thereby clarifying the temperature sensing threshold of the detection device; 2) The relationship between the minimum breaking force of the wire strands at different temperatures and the maximum allowable axial tensile force of the line is used as the basis for judgment, thereby finding the characteristic temperature of different degrees of wire breakage; 3) It is assumed that the heat of short-term thermal defects comes from the Joule heating of the contact resistance at the contact position between the fitting and the line, and the arc heating of the breakdown discharge. The order of broken strands is arranged from the wire strand closest to the fitting, from the outside to the inside; 4) Different degrees of damage are classified and discussed, comprehensively covering multiple degrees of damage with the number of broken strands of 1, m, and N. All cases of the line from intact to broken can be calculated.

[0114] The above is a method for analyzing the degree of damage to internal wire strands in hardware provided in the embodiments of this application. The following is a system for analyzing the degree of damage to internal wire strands in hardware provided in the embodiments of this application.

[0115] Please see Figure 2 The present application provides a hardware internal strand damage analysis system, comprising:

[0116] The first calculation unit 201 is used to calculate the minimum breaking force F of the entire circuit containing n strands and a single strand under normal temperature and conditions. A and F a Based on minimum breaking force F A and F a Calculate the total number of broken strands m in the entire line, and calculate the maximum allowable average force F on a single strand. b(m) ;

[0117] The second calculation unit 202 is used to calculate the tensile strength R of the strand at temperature T. T Therefore, the minimum breaking force F of a single strand at temperature T can be calculated. a,T ;

[0118] The first analysis unit 203 is used to analyze the maximum permissible average force F. b(m) and minimum breaking force F a,T Comparative analysis shows that when the minimum breaking force F a,T Greater than the maximum allowable average force F b(m) Then, after adjusting the temperature T, the second calculation unit is triggered, and the minimum breaking force F... a,T Not greater than the maximum permissible average force F b(m) If the wire strand is determined to be in a broken state, then temperature T is taken as the characteristic temperature T. c(m) ;

[0119] The third calculation unit 204 is used to mark the location of the broken strand according to the number of broken strands m; and to establish a local geometric model of the line-fitting system, set a short-time excitation I(t) as input to the finite element simulation model to calculate the average temperature T of the line cross section where the marked broken strand m is located. avr(m) ;

[0120] The second analysis unit 205 is used to compare the average temperature T of the strand cross section. avr(m) and characteristic temperature T c(m) When the average temperature of the cross section of the wire strand T avr(m) Less than the characteristic temperature T c(m) Then, after readjusting the short-time excitation I(t), the third calculation unit is triggered to perform simulation calculations. When the average temperature T of the strand cross section... avr(m) Not less than the characteristic temperature T c(m) Then we obtain the characteristic excitation I. m (t), and calculate the temperature sensing threshold T of the detection device. m ;

[0121] Output unit 206 is used to output the number of broken shares m and the characteristic excitation I. m(t) and the temperature threshold T of the detection device m .

[0122] Furthermore, this application embodiment also provides a device for analyzing the degree of damage to internal wire strands in hardware, the device including a processor and a memory:

[0123] The memory is used to store program code and transmit the program code to the processor;

[0124] The processor is used to execute the steps of the method for analyzing the degree of damage to internal wire strands of hardware as described in the above method embodiments, according to the instructions in the program code.

[0125] Furthermore, this application embodiment also provides a computer-readable storage medium for storing program code, which is used to execute the method for analyzing the degree of damage to internal wire strands of hardware described in the above method embodiment.

[0126] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0127] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0128] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0129] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0130] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0131] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0132] If the integrated unit is implemented as a software functional unit 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 this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0133] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for analyzing the degree of damage to internal wire strands in hardware, characterized in that, include: S1. Calculate the minimum breaking force F of the entire circuit containing n strands and a single strand under normal temperature and conditions. A and F a Based on minimum breaking force F A and F a Calculate the total number of broken strands m in the entire line, and calculate the maximum allowable average force F on a single strand. b(m) ; S2, Calculate the tensile strength R of the wire strand at temperature T. T Therefore, the minimum breaking force F of a single strand at temperature T can be calculated. a,T ; S3, regarding the maximum permissible average force F b(m) and minimum breaking force F a,T Comparative analysis shows that when the minimum breaking force F a,T Greater than the maximum allowable average force F b(m) Then, after adjusting the temperature T, return to step S2. When the minimum breaking force F... a,T Not greater than the maximum permissible average force F b(m) If the wire strand is determined to be in a broken state, then temperature T is taken as the characteristic temperature T. c(m) ; S4. Mark the location of the broken strands according to the number of broken strands m; establish a local geometric model of the line-fittings, set a short-time excitation I(t) input to the finite element simulation model for calculation, and obtain the marked broken strands m. i Average temperature T of the cross section of the line avr(m) ; S5, Compare the average temperature T of the cross-section of the strands avr(m) and characteristic temperature T c(m) When the average temperature of the cross section of the wire strand T avr(m) Less than the characteristic temperature T c(m) Then, after readjusting the short-time excitation I(t), return to step S4 for simulation calculation. When the average temperature T of the wire strand cross section... avr(m) Not less than the characteristic temperature T c(m) Then we obtain the characteristic excitation I. m (t), and calculate the temperature sensing threshold T of the detection device. m ; S6, Output the number of broken shares m, Feature stimulus I m (t) and the temperature threshold T of the detection device m .

2. The method for analyzing the degree of damage to internal wire strands in hardware according to claim 1, characterized in that, The calculation includes the minimum breaking force F of the entire circuit with n strands and the minimum breaking force F of each individual strand under normal temperature and conditions. A and F a Based on minimum breaking force F A and F a Calculate the total number of broken strands m in the entire line, and calculate the maximum allowable average force F on a single strand. b(m) Specifically, it includes: Calculate the minimum breaking force F of a circuit consisting of n strands and a single strand under normal temperature and conditions. A and F a Based on the minimum breaking force F of the entire line A Calculate the maximum allowable axial tensile force F of the entire line. B Based on the maximum permissible axial tensile force F of the entire line B Calculate the maximum allowable number of broken strands N in the circuit; The total number of strand breaks, m, is determined based on the maximum permissible number of strand breaks, N; and based on the number of strand breaks, m, and the maximum permissible axial tensile force, F... B Calculate the maximum permissible average force F on a single strand. b(m) .

3. The method for analyzing the degree of damage to internal wire strands in hardware according to claim 1, characterized in that, The tensile strength R of the strand corresponding to the calculated temperature T T Therefore, the minimum breaking force F of a single strand at temperature T can be calculated. a,T Specifically, it includes: Calculate the tensile strength R of the strand at temperature T based on the reduction factor. T According to the tensile strength R of the strand T Calculate the minimum breaking force F of a single strand at temperature T by considering the cross-sectional area and number of strands. a,T .

4. The method for analyzing the degree of damage to internal wire strands in hardware according to claim 1, characterized in that, The step of marking the location of the broken stock according to the number of broken stocks m specifically includes: Assumptions: The temperature characteristics of short-term thermal defects in the circuit start with the strand closest to the fitting, with the temperature of the strand closer to the fitting contact surface being higher, the temperature of the strand closer to the middle being lower, and the temperature of the very center strand being the lowest; and under the condition of short-term thermal defects, the order of strand breakage in the circuit starts from the outermost strand closest to the fitting, with the breakage occurring later as the strands move closer to the center, and the very center strand breaking last. Then: Based on the above assumptions, and marking the location of the broken shares according to the number of broken shares m, we obtain the broken share m. i .

5. A system for analyzing the degree of damage to internal wire strands in hardware, characterized in that, include: The first calculation unit is used to calculate the minimum breaking force F of the entire circuit containing n strands and a single strand under normal temperature and conditions. A and F a Based on minimum breaking force F A and F a Calculate the total number of broken strands m in the entire line, and calculate the maximum allowable average force F on a single strand. b(m) ; The second calculation unit is used to calculate the tensile strength R of the strand at temperature T. T Therefore, the minimum breaking force F of a single strand at temperature T can be calculated. a,T ; The first analysis unit is used to analyze the maximum permissible average force F. b(m) and minimum breaking force F a,T Comparative analysis shows that when the minimum breaking force F a,T Greater than the maximum allowable average force F b(m) Then, after adjusting the temperature T, the second calculation unit is triggered, and the minimum breaking force F... a,T Not greater than the maximum permissible average force F b(m) If the wire strand is determined to be in a broken state, then temperature T is taken as the characteristic temperature T. c(m) ; The third calculation unit is used to mark the location of the broken strands according to the number m of broken strands; and to establish a local geometric model of the line-fittings, set a short-time excitation I(t) as input to the finite element simulation model to calculate the marked broken strands m. i Average temperature T of the cross section of the line avr(m) ; The second analysis unit is used to compare the average temperature T of the strand cross-section. avr(m) and characteristic temperature T c(m) When the average temperature of the cross section of the wire strand T avr(m) Less than the characteristic temperature T c(m) Then, after readjusting the short-time excitation I(t), the third calculation unit is triggered to perform simulation calculations. When the average temperature T of the strand cross section... avr(m) Not less than the characteristic temperature T c(m) Then we obtain the characteristic excitation I. m (t), and calculate the temperature sensing threshold T of the detection device. m ; Output unit, used to output the number of broken shares m and the characteristic excitation I. m (t) and the temperature threshold T of the detection device m .

6. The hardware internal strand damage analysis system according to claim 5, characterized in that, The first computing unit is specifically used for: Calculate the minimum breaking force F of a circuit consisting of n strands and a single strand under normal temperature and conditions. A and F a Based on the minimum breaking force F of the entire line A Calculate the maximum allowable axial tensile force F of the entire line. B Based on the maximum permissible axial tensile force F of the entire line B Calculate the maximum allowable number of broken strands N in the circuit; The total number of broken strands m of the line is determined based on the maximum allowable number of broken strands N; And based on the number of broken strands m and the maximum permissible axial tensile force F B Calculate the maximum permissible average force F on a single strand. b(m) .

7. The hardware internal strand damage analysis system according to claim 5, characterized in that, The second computing unit is specifically used for: Calculate the tensile strength R of the strand at temperature T based on the reduction factor. T According to the tensile strength R of the strand T Calculate the minimum breaking force F of a single strand at temperature T by considering the cross-sectional area and number of strands. a,T .

8. The hardware internal strand damage analysis system according to claim 5, characterized in that, The step of marking the location of the broken stock according to the number of broken stocks m specifically includes: Assumptions: The temperature characteristics of short-term thermal defects in the circuit start with the strand closest to the fitting, with the temperature of the strand closer to the fitting contact surface being higher, the temperature of the strand closer to the middle being lower, and the temperature of the very center strand being the lowest; and under the condition of short-term thermal defects, the order of strand breakage in the circuit starts from the outermost strand closest to the fitting, with the breakage occurring later as the strands move closer to the center, and the very center strand breaking last. Then: Based on the above assumptions, and marking the location of the broken shares according to the number of broken shares m, we obtain the broken share m. i .

9. A device for analyzing the degree of damage to internal wire strands in hardware, characterized in that, The device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the method for analyzing the degree of damage to internal wire strands of hardware according to any one of claims 1-4, based on the instructions in the program code.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program code for executing the method for analyzing the degree of damage to internal wire strands of hardware as described in any one of claims 1-4.

Images