Cable core through-flow efficiency detection method and device

Abstract

The invention discloses a cable core through-flow efficiency detection method and device, and belongs to the technical field of distribution network cables, and the method comprises the steps: obtaining a to-be-detected cable sample; respectively measuring the sample total volume of the to-be-measured cable sample and the cable core volume of the to-be-measured cable core by using an equivalent volume replacement method; measuring the cable length and the adhesive tape volume of the cable core to be measured; calculating the cross-sectional area of the through-flow cable based on the sample total volume, the adhesive tape volume and the cable length; calculating a compression coefficient based on the cross-sectional area of the through-flow cable and the structural parameters of the cable core to be measured; calculating a conductive cross section ratio based on the sample total volume, the wire core volume and the adhesive tape volume; calculating a direct-current resistance coefficient based on the nominal sectional area of the cable core to be measured and the sectional area of the through-flow cable; and detecting the cable core through-flow efficiency of the to-be-detected cable sample according to the compression coefficient, the conductive cross section ratio and the direct-current resistance coefficient. Therefore, by implementing the method, the problem that the conductivity of the cable is difficult to accurately represent in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution network cables, and in particular to a method and device for detecting the flow efficiency of a cable core. Background Art

[0002] In power transmission, industrial manufacturing, and modern communications, cables serve as the core carriers of energy and information transfer. Their electrical conductivity is directly related to system safety, energy efficiency, and economic efficiency, profoundly impacting many core application scenarios, such as current carrying capacity control and temperature rise control in power transmission. The electrical conductivity of cables is often characterized by their compression coefficient.

[0003] The existing method for calculating the compression coefficient is "actual cross-sectional area of the conductor after compression / total cross-sectional area of the single conductor wires before compression." However, in actual applications, the cable production process involves twisting and compression to keep the core wires in close contact and prevent them from falling apart, thereby reducing the air gap between the core wires. During this process, the core wires of the cable will undergo severe deformation and a certain degree of elongation, resulting in a reduction in their cross-sectional area. Furthermore, it is impossible to measure the degree of reduction in the cross-sectional area of each single wire through conventional means. Therefore, the conventional compression coefficient calculation formula cannot obtain the actual flow area of the formed cable, making it difficult to accurately calculate the compression coefficient of the cable, and thus difficult to characterize the conductive performance of the cable. Summary of the Invention

[0004] The present invention provides a method and device for detecting the current flow efficiency of a cable core, which can solve the problem in the prior art that it is difficult to accurately characterize the conductive performance of the cable.

[0005] In order to solve the above technical problems, the present invention provides a method for detecting the flow efficiency of a cable core, comprising:

[0006] Obtain a cable sample to be tested; wherein the cable sample to be tested includes a cable segment to be tested and a tape wrapping the cable segment; the cable segment includes a cable core to be tested and an outer insulation layer wrapping the cable core to be tested;

[0007] Using an equivalent volume replacement method, the total sample volume of the cable sample to be tested and the core volume of the cable core to be tested are measured respectively;

[0008] Measuring the length of the cable core to be tested to obtain the cable length;

[0009] measuring the volume of the tape to form a tape volume;

[0010] Calculating the cross-sectional area of the cable through which the flow passes based on the total volume of the sample, the volume of the tape, and the length of the cable;

[0011] Calculating a compression coefficient based on the cross-sectional area of the current-carrying cable and the structural parameters of the cable core to be tested;

[0012] Calculating a conductive cross-sectional area ratio based on the total volume of the sample, the volume of the wire core, and the volume of the tape;

[0013] Calculating the DC resistance coefficient based on the nominal cross-sectional area of the cable core to be tested and the cross-sectional area of the current-carrying cable;

[0014] The cable core current flow efficiency of the cable sample to be tested is detected according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient.

[0015] As a preferred solution, the calculation of the cross-sectional area of the cable through which the flow passes based on the total volume of the sample, the volume of the tape and the length of the cable comprises:

[0016] The volume of the cable segment is obtained by subtracting the volume of the tape from the total sample volume of the cable sample to be tested:

[0017] Based on the cable segment volume and the cable length, the following formula is used to calculate the cable cross-sectional area of the cable core to be tested:

[0018]

[0019] Where S1 is the cross-sectional area of the cable; V4 is the volume of the cable segment; L e is the cable length.

[0020] As a preferred solution, the calculation of the compression coefficient based on the cross-sectional area of the current-carrying cable and the structural parameters of the cable core to be tested includes:

[0021] Obtaining structural parameters of the cable core to be tested; wherein the structural parameters include the number of single core wires and the cross-sectional area of the single core wires;

[0022] Calculating a compression coefficient based on the cross-sectional area of the current-carrying cable, the number of single-wire cores, and the cross-sectional area of the single-wire cores;

[0023]

[0024] Where K s is the compression coefficient; S1 is the cross-sectional area of the current-carrying cable; n is the number of single core wires; S l It is the cross-sectional area of a single wire core.

[0025] As a preferred solution, the calculation of the conductive cross-section ratio based on the total volume of the sample, the volume of the wire core, and the volume of the tape includes:

[0026]

[0027] Where K cis the conductive cross-section ratio; V2 is the core volume; V1 is the total volume of the sample; V3 is the tape volume.

[0028] As a preferred solution, the calculation of the DC resistance coefficient based on the nominal cross-sectional area of the cable core to be tested and the cross-sectional area of the current-carrying cable includes:

[0029]

[0030] Where, ε r is the DC resistance coefficient; S0 is the nominal cross-sectional area; S1 is the cross-sectional area of the current-carrying cable.

[0031] As a preferred solution, the detecting the cable core current efficiency of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient includes:

[0032] Based on the compression coefficient and the conductive cross-section ratio, determining whether the cable sample to be tested meets a preset first conductive performance condition;

[0033] Determining whether the cable sample to be tested meets a preset second conductivity performance condition based on the DC resistance coefficient;

[0034] When the cable sample to be tested meets both the preset first conductivity performance condition and the preset second conductivity performance condition, it is determined that the cable core flow efficiency of the cable sample to be tested meets the standard; otherwise, it is determined that the cable core flow efficiency of the cable sample to be tested does not meet the standard.

[0035] As a preferred solution, judging whether the cable sample to be tested meets a preset first conductive performance condition based on the compression coefficient and the conductive cross-section ratio includes:

[0036] Obtaining the compression coefficient threshold and the conductive cross-section ratio threshold;

[0037] When the compression coefficient is greater than the compression coefficient threshold or the conductive cross-section ratio is greater than the conductive cross-section ratio threshold, it is determined that the cable sample to be tested meets the preset first conductive performance condition.

[0038] As a preferred solution, judging whether the cable sample to be tested meets a preset second conductivity performance condition based on the DC resistance coefficient includes:

[0039] Get the DC resistance coefficient threshold;

[0040] When the DC resistance coefficient is less than the DC resistance coefficient threshold, it is determined that the cable sample to be tested meets the preset second conductive performance condition.

[0041] As a preferred solution, after detecting the cable core current efficiency of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient, the method further includes:

[0042] Based on the cable length and the core volume, the conductor cross-sectional area of the cable core to be tested is calculated using the following formula:

[0043]

[0044] Where S2 is the conductor cross-sectional area; V2 is the core volume; L e is the cable length;

[0045] Obtain the mass and density of the cable core to be tested, and calculate the verification volume of the cable core to be tested using the following formula;

[0046]

[0047] Where V5 is the verification volume of the cable core to be tested; m is the mass of the cable core to be tested; ρ is the density of the cable core to be tested;

[0048] Based on the verification volume and the cable length, the verification area of the cable core to be tested is calculated using the following formula;

[0049]

[0050] Where S3 is the verification area of the cable core to be tested; V5 is the verification volume of the cable core to be tested; L e is the cable length;

[0051] Based on the conductor cross-sectional area and the verification area, the error coefficient is calculated using the following formula;

[0052]

[0053] Where θ is the error coefficient; S2 is the conductor cross-sectional area; S3 is the verification area of the cable core to be tested;

[0054] Based on the error coefficient, the current flow efficiency of the cable core is verified.

[0055] Accordingly, the present invention provides a cable core flow efficiency detection device, comprising: a sample acquisition module, a first volume measurement module, a length measurement module, a second volume measurement module, a cross-sectional area calculation module, a compression coefficient calculation module, a conductive cross-sectional area ratio calculation module, a DC resistance coefficient calculation module, and a flow efficiency detection module;

[0056] The sample acquisition module is used to obtain a cable sample to be tested; wherein the cable sample to be tested includes a cable segment to be tested and a tape wrapping the cable segment; the cable segment includes a cable core to be tested and an outer insulation layer wrapping the cable core to be tested;

[0057] The first volume measurement module is used to measure the total sample volume of the cable sample to be tested and the core volume of the cable core to be tested respectively by using an equivalent volume replacement method;

[0058] The length measurement module is used to measure the length of the cable core to be tested to form the cable length;

[0059] The second volume measurement module is used to measure the volume of the tape to form the tape volume;

[0060] The cross-sectional area calculation module is used to calculate the cross-sectional area of the cable through which the flow passes based on the total volume of the sample, the volume of the tape and the length of the cable;

[0061] The compression coefficient calculation module is used to calculate the compression coefficient based on the cross-sectional area of the current-carrying cable and the structural parameters of the cable core to be tested;

[0062] The conductive cross-sectional ratio calculation module is used to calculate the conductive cross-sectional ratio based on the total volume of the sample, the volume of the wire core and the volume of the tape;

[0063] The DC resistance coefficient calculation module is used to calculate the DC resistance coefficient based on the nominal cross-sectional area of the cable core to be tested and the cross-sectional area of the current-carrying cable;

[0064] The flow efficiency detection module detects the cable core flow efficiency of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient.

[0065] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0066] The present invention provides a method for detecting the flow efficiency of a cable core, comprising the steps of obtaining a cable sample to be tested; measuring the total sample volume and the core volume of the cable core to be tested of the cable sample by an equivalent volume replacement method; measuring the cable length and the tape volume of the cable core to be tested; calculating the flow cable cross-sectional area based on the total sample volume, the tape volume and the cable length; calculating the compression coefficient based on the flow cable cross-sectional area and the structural parameters of the cable core to be tested; calculating the conductive cross-sectional area ratio based on the total sample volume, the core volume and the tape volume; calculating the DC resistivity based on the nominal cross-sectional area of the cable core to be tested and the flow cable cross-sectional area; and detecting the flow efficiency of the cable core of the cable sample to be tested based on the compression coefficient, the conductive cross-sectional area ratio and the DC resistivity. The present invention solves the problem that the current compression coefficient cannot be directly calculated. By defining the flow cable cross-sectional area, the conductive cross-sectional area ratio and the DC resistivity, and improving the calculation method of the compression coefficient, the flow efficiency of the cable core can be detected by analyzing the flow cable cross-sectional area, the compression coefficient, the conductive cross-sectional area ratio and the DC resistivity, thereby accurately characterizing the conductive performance of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0068] Figure 1 A schematic flow chart of an embodiment of a method for detecting the flow efficiency of a cable core provided by the present invention;

[0069] Figure 2 A schematic cross-sectional view of a cable sample provided by the present invention;

[0070] Figure 3 This is a structural schematic diagram of an embodiment of a cable core flow efficiency detection device provided by the present invention. DETAILED DESCRIPTION

[0071] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0072] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0073] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0074] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0075] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0076] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0077] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0078] Example 1

[0079] See also Figure 1To solve the problem in the prior art that it is difficult to accurately characterize the conductive performance of a cable, an embodiment of the present invention provides a method for detecting the current flow efficiency of a cable core. The method includes steps 101 to 109, each of which is specifically as follows:

[0080] Step 101: Obtain a cable sample to be tested; wherein the cable sample to be tested includes a cable segment to be tested and a tape wrapping the cable segment; the cable segment includes a cable core to be tested and an outer insulation layer wrapping the cable core to be tested.

[0081] In an embodiment of the present invention, the cable itself can be regarded as a cylinder with a uniform cross-section, which is composed of a cable core and an outer insulation layer. The cable core is composed of a plurality of single core wires. Use a suitable cutting tool to cut in a direction perpendicular to the axis of the cable core to cut off a cable segment of a certain length. When cutting, it is necessary to ensure that the cut surface is flat and strictly keep it perpendicular to the axis of the cable core to ensure the accuracy of the measurement data and the reliability of subsequent processing. After cutting the cable segment, use waterproof tape to tightly wrap the cut surfaces at both ends of the cable segment to keep it stable as a whole, thereby forming a cable sample. When wrapping the tape, it should be ensured that it fits evenly so as not to affect the subsequent measurement accuracy.

[0082] See also Figure 2 Figure 1 is a schematic cross-sectional view of a cable sample provided by the present invention. The cable core consists of five single core wires, and adhesive tape is wrapped around the sides and cross-section of the cable sample. To reduce measurement errors, the amount of adhesive tape used should be minimized.

[0083] Step 102: using an equivalent volume replacement method, respectively measuring the total sample volume of the cable sample to be tested and the core volume of the cable core to be tested.

[0084] In this embodiment of the present invention, a cable sample to be tested is slowly placed into a container of clean water. Ensure that the cable sample is completely submerged in the water, leaving no air bubbles, and observe changes in the water surface. The volume of water overflowed by the submerged cable is measured using a graduated cylinder or the overflow method, and this volume is recorded as the total sample volume of the cable sample to be tested.

[0085] In an embodiment of the present invention, after the total sample volume of the cable sample to be tested is measured, the cable sample to be tested is taken out of the water, and a clean fiber-free towel or absorbent paper is used to carefully wipe off the residual moisture on the surface of the cable sample to be tested. The cable core to be tested is then placed in a drying oven or dried thoroughly using hot air equipment to ensure that it does not contain any moisture inside and outside in order to proceed to the next step of the experiment. After drying, the wrapped tape is removed, and the cable sample to be tested is stripped using a knife or wire strippers to remove the outer insulation layer and filler of the cable sample to be tested, leaving only the core portion of the cable to be tested. In the process of stripping the outer insulation layer, attention should be paid to the operating specifications, and the copper wire should be kept intact as a whole to avoid damaging the core structure.

[0086] In an embodiment of the present invention, the separately taken out cable core to be tested is slowly placed back into the water container, and the volume of water overflow caused by the immersion of the copper wire is similarly observed and measured, and the volume data is recorded as the core volume of the cable core to be tested.

[0087] The cut surface of the cable sample to be tested of the present invention is wrapped with a waterproof tape, which can effectively prevent water from entering the gaps in the cable, thereby reducing measurement errors.

[0088] Step 103: Measure the length of the cable core to be tested to obtain the cable length.

[0089] In this embodiment of the present invention, after measuring the total sample volume of the cable sample and the core volume of the cable core under test using the equivalent volume replacement method, the length of the cable core under test is measured using a precise measuring tool. Because the cable sample under test is cut perpendicular to the cable core axis, the measured length of the cable core under test is equivalent to the length of the cable sample under test, and this length is therefore recorded as the cable length.

[0090] Step 104: Measure the volume of the tape to form a tape volume.

[0091] In an embodiment of the present invention, after the tape is removed from the cable sample to be tested, the physical dimensions of the tape are measured in detail using a precision measuring tool to calculate the volume of the tape. For example, when the tape is a regular rectangular parallelepiped, a precision measuring tool (such as a vernier caliper or micrometer) can be used to measure the thickness of the tape. The selected thickness measurement points need to ensure that the thickness is uniform and representative to obtain accurate data, thereby recording the measured tape thickness. Next, a tape measure or ruler is used to measure the total length of the tape, and the tape is measured from the starting end to the ending end along the direction of tape expansion. During the measurement process, the tape is straightened to reduce errors, and the measured tape length is recorded. Finally, the tape width is measured in a direction perpendicular to the tape length, and multiple positions are selected for measurement and the width average is calculated to confirm its width consistency, and the width average is recorded as the tape width. The tape thickness, tape length, and tape width obtained by the above measurements are multiplied to calculate the tape volume.

[0092] Step 105: Calculate the cross-sectional area of the cable through which the flow passes based on the total volume of the sample, the volume of the tape, and the length of the cable.

[0093] As a preferred solution of this embodiment, the cross-sectional area of the cable through which the flow passes is calculated based on the total volume of the sample, the volume of the tape, and the length of the cable, including:

[0094] The volume of the cable segment is obtained by subtracting the volume of the tape from the total sample volume of the cable sample to be tested:

[0095] Based on the cable segment volume and the cable length, the following formula is used to calculate the cable cross-sectional area of the cable core to be tested:

[0096]

[0097] Where S1 is the cross-sectional area of the cable; V4 is the volume of the cable segment; L e is the cable length.

[0098] In the embodiment of the present invention, the cross-sectional area of the cable through which current flows is the cross-sectional area of the cable. Since the cable sample to be tested includes the tape and the cable segment, the volume of the cable segment can be calculated by subtracting the volume of the tape from the total sample volume of the cable sample to be tested. Since the cable length can be obtained through the above measurement, the actual cross-sectional area of the cable sample through which current flows can be calculated by dividing the volume of the cable segment by the cable length.

[0099] Step 106: Calculate the compression coefficient based on the cross-sectional area of the current-carrying cable and the structural parameters of the cable core to be tested.

[0100] As a preferred solution of this embodiment, the compression coefficient is calculated based on the cross-sectional area of the current-carrying cable and the structural parameters of the cable core to be tested, including:

[0101] Obtaining structural parameters of the cable core to be tested; wherein the structural parameters include the number of single core wires and the cross-sectional area of the single core wires;

[0102] Calculating a compression coefficient based on the cross-sectional area of the current-carrying cable, the number of single-wire cores, and the cross-sectional area of the single-wire cores;

[0103]

[0104] Where K s is the compression coefficient; S1 is the cross-sectional area of the current-carrying cable; n is the number of single core wires; S l It is the cross-sectional area of a single wire core.

[0105] In an embodiment of the present invention, the compression coefficient is defined as "actual cross-sectional area of the conductor after compression / total cross-sectional area of the conductor single wire before compression". Since the cable core is composed of multiple core single wires, when calculating the total cross-sectional area of the conductor single wires, the structural parameters such as the number of core single wires and the cross-sectional area of the core single wire of the cable core to be tested can be obtained first. The structural parameters of the cable core to be tested can be obtained based on the factory documents provided by the manufacturer. The total cross-sectional area of the conductor single wire can be calculated by multiplying the number of core single wires of the cable core to be tested by the cross-sectional area of the core single wire. Then, the cross-sectional area of the current-carrying cable obtained by the above calculation is divided by the total cross-sectional area of the conductor single wire to calculate the compression coefficient.

[0106] In practical applications, cable core structural data varies from manufacturer to manufacturer, and factory documentation for cable cores is often missing, making it difficult to obtain the structural parameters of the cable core under test. Therefore, when evaluating the conductivity of the cable under test, in addition to calculating the compression coefficient, the conductive cross-sectional area ratio and DC resistivity can also be used to characterize the conductivity of the cable under test.

[0107] Step 107: Calculate the conductive cross-section ratio based on the total volume of the sample, the volume of the wire core, and the volume of the tape.

[0108] As a preferred solution of this embodiment, the conductive cross-section ratio is calculated based on the total volume of the sample, the volume of the wire core, and the volume of the tape, including:

[0109]

[0110] Where K c is the conductive cross-section ratio; V2 is the core volume; V1 is the total volume of the sample; V3 is the tape volume.

[0111] In an embodiment of the present invention, a parameter called the cable's conductive cross-sectional area ratio can be defined to measure the cross-sectional area utilization of the cable after forming. The conductive cross-sectional area ratio is defined as the ratio of the cable core volume to the cable segment volume. The conductive cross-sectional area ratio is calculated to measure the conductive cross-sectional area utilization of the cable core under test. The cable segment volume is calculated by subtracting the tape volume from the total sample volume. A closer conductive cross-sectional area ratio to 1 indicates a higher utilization of the conductive material and better conductivity.

[0112] Step 108: Calculate the DC resistance coefficient based on the nominal cross-sectional area of the cable core to be tested and the cross-sectional area of the current-carrying cable.

[0113] As a preferred solution of this embodiment, the DC resistance coefficient is calculated based on the nominal cross-sectional area of the cable core to be tested and the cross-sectional area of the current-carrying cable, including:

[0114]

[0115] Where, ε r is the DC resistance coefficient; S0 is the nominal cross-sectional area; S1 is the cross-sectional area of the current-carrying cable.

[0116] In the embodiment of the present invention, since the DC resistance of the conductor is inversely proportional to the cross-sectional area, the conductivity of the cable core can also be detected by defining the DC resistance coefficient. Since the current carrying capacity of the cable is measured by the nominal cross-sectional area, the DC resistance coefficient can be defined as the ratio of the actual DC resistance of the cable to the nominal DC resistance. Among them, the nominal cross-sectional area of the cable core can be obtained through the factory documents when the cable core leaves the factory. The nominal cross-sectional area of the cable core can be 800mm 2 , 1200mm 2 , 1600mm 2 , 2000mm 2 or 2500mm 2 wait.

[0117] Step 109: detecting the current flow efficiency of the cable core of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio, and the DC resistance coefficient.

[0118] In an embodiment of the present invention, based on the various data obtained from the measurements of the cable sample to be tested, four data quantities can be calculated: the cross-sectional area of the cable carrying the flow, the compression coefficient, the conductive cross-sectional area ratio, and the DC resistance coefficient. These four data quantities can be used to measure the actual current-carrying capacity of the cable relative to the nominal conditions, as well as the efficiency of the cable core space utilization. Since the cross-sectional area of the cable carrying the flow is used in the calculation of the compression coefficient and the DC resistance coefficient, the cross-sectional area of the cable carrying the flow can be indirectly characterized by detecting the compression coefficient and the DC resistance coefficient. Therefore, by analyzing the compression coefficient, the conductive cross-sectional area ratio, and the DC resistance coefficient, the current-carrying efficiency of the cable core of the cable sample to be tested can be detected.

[0119] As a preferred solution of this embodiment, detecting the cable core current efficiency of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient includes:

[0120] Based on the compression coefficient and the conductive cross-section ratio, determining whether the cable sample to be tested meets a preset first conductive performance condition;

[0121] Determining whether the cable sample to be tested meets a preset second conductivity performance condition based on the DC resistance coefficient;

[0122] When the cable sample to be tested meets both the preset first conductivity performance condition and the preset second conductivity performance condition, it is determined that the cable core flow efficiency of the cable sample to be tested meets the standard; otherwise, it is determined that the cable core flow efficiency of the cable sample to be tested does not meet the standard.

[0123] In an embodiment of the present invention, two conductivity performance conditions are set for the three data quantities of compression coefficient, conductive cross-section ratio, and DC resistivity to determine whether the cable core current flow efficiency meets the standard. The first conductivity performance condition is set based on the compression coefficient and conductive cross-section ratio, and the second conductivity performance condition is set based on the DC resistivity. Only when the cable sample under test meets both the first and second conductivity performance conditions is the cable core current flow efficiency determined to be substandard.

[0124] As a preferred solution of this embodiment, judging whether the cable sample to be tested meets a preset first conductive performance condition based on the compression coefficient and the conductive cross-section ratio includes:

[0125] Obtaining the compression coefficient threshold and the conductive cross-section ratio threshold;

[0126] When the compression coefficient is greater than the compression coefficient threshold or the conductive cross-section ratio is greater than the conductive cross-section ratio threshold, it is determined that the cable sample to be tested meets the preset first conductive performance condition.

[0127] In an embodiment of the present invention, a first conductivity condition can be formed by setting a compression coefficient threshold and a conductive cross-sectional area ratio threshold based on actual data. When the compression coefficient or the conductive cross-sectional area ratio is greater than the corresponding threshold, the cable sample under test is determined to meet the preset first conductivity condition.

[0128] As a preferred solution of this embodiment, judging whether the cable sample to be tested meets a preset second conductivity performance condition based on the DC resistance coefficient includes:

[0129] Get the DC resistance coefficient threshold;

[0130] When the DC resistance coefficient is less than the DC resistance coefficient threshold, it is determined that the cable sample to be tested meets the preset second conductive performance condition.

[0131] In an embodiment of the present invention, a second conductivity condition can be established by setting a DC resistivity threshold based on actual data. Since the DC resistance of a conductor is inversely proportional to its cross-sectional area, when the DC resistivity is less than the DC resistivity threshold, the cable sample under test is determined to meet the preset second conductivity condition.

[0132] As a preferred solution of this embodiment, after detecting the cable core current efficiency of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient, the method further includes:

[0133] Based on the cable length and the core volume, the conductor cross-sectional area of the cable core to be tested is calculated using the following formula:

[0134]

[0135] Where S2 is the conductor cross-sectional area; V2 is the core volume; L e is the cable length;

[0136] Obtain the mass and density of the cable core to be tested, and calculate the verification volume of the cable core to be tested using the following formula;

[0137]

[0138] Where V5 is the verification volume of the cable core to be tested; m is the mass of the cable core to be tested; ρ is the density of the cable core to be tested;

[0139] Based on the verification volume and the cable length, the verification area of the cable core to be tested is calculated using the following formula;

[0140]

[0141] Where S3 is the verification area of the cable core to be tested; V5 is the verification volume of the cable core to be tested; Le is the cable length;

[0142] Based on the conductor cross-sectional area and the verification area, the error coefficient is calculated using the following formula;

[0143]

[0144] Where θ is the error coefficient; S2 is the conductor cross-sectional area; S3 is the verification area of the cable core to be tested;

[0145] Based on the error coefficient, the current flow efficiency of the cable core is verified.

[0146] In an embodiment of the present invention, after obtaining the test results of the cable core flow efficiency of the cable sample to be tested by analyzing the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient, the test results of the cable core flow efficiency can also be verified by using the weighing method as an auxiliary measurement means. Specifically, first, based on the measured cable length and core volume, the conductor cross-sectional area of the cable core to be tested is calculated. Then, the mass of the cable core to be tested is weighed by using a precision electronic balance (with an accuracy of not less than 0.01g), and the temperature and humidity of the measurement environment are recorded at the same time to ensure that the environment is stable and reduce weighing errors. The density of the cable core to be tested is then determined according to the metal type of the cable core to be tested. For example, the density of copper is ρ Cu =8.96g / cm 3 The verification volume of the cable core to be tested is calculated based on the mass and density of the cable core to be tested. Then, based on the verification volume and the cable length obtained from the above measurement, the verification area of the cable core to be tested is calculated. Finally, the difference in data obtained by the equivalent volume replacement method and the weighing method is expressed in the form of relative error. An error coefficient threshold is set in advance. If the calculated error coefficient is less than the error coefficient threshold, it is determined that the test result of the cable core flow efficiency obtained above has been verified.

[0147] The implementation of the above embodiment has the following effects:

[0148] The present invention provides a method for detecting the flow efficiency of a cable core, comprising the steps of obtaining a cable sample to be tested; measuring the total sample volume and the core volume of the cable core to be tested of the cable sample by an equivalent volume replacement method; measuring the cable length and the tape volume of the cable core to be tested; calculating the flow cable cross-sectional area based on the total sample volume, the tape volume and the cable length; calculating the compression coefficient based on the flow cable cross-sectional area and the structural parameters of the cable core to be tested; calculating the conductive cross-sectional area ratio based on the total sample volume, the core volume and the tape volume; calculating the DC resistivity based on the nominal cross-sectional area of the cable core to be tested and the flow cable cross-sectional area; and detecting the flow efficiency of the cable core of the cable sample to be tested based on the compression coefficient, the conductive cross-sectional area ratio and the DC resistivity. The present invention solves the problem that the current compression coefficient cannot be directly calculated. By defining the flow cable cross-sectional area, the conductive cross-sectional area ratio and the DC resistivity, and improving the calculation method of the compression coefficient, the flow efficiency of the cable core can be detected by analyzing the flow cable cross-sectional area, the compression coefficient, the conductive cross-sectional area ratio and the DC resistivity, thereby accurately characterizing the conductive performance of the cable.

[0149] like Figure 3 As shown, based on the above method embodiment, a corresponding device embodiment is provided;

[0150] An embodiment of the present invention provides a cable core flow efficiency detection device, comprising: a sample acquisition module, a first volume measurement module, a length measurement module, a second volume measurement module, a cross-sectional area calculation module, a compression coefficient calculation module, a conductive cross-sectional area ratio calculation module, a DC resistance coefficient calculation module, and a flow efficiency detection module;

[0151] The sample acquisition module is used to obtain a cable sample to be tested; wherein the cable sample to be tested includes a cable segment to be tested and a tape wrapping the cable segment; the cable segment includes a cable core to be tested and an outer insulation layer wrapping the cable core to be tested;

[0152] The first volume measurement module is used to measure the total sample volume of the cable sample to be tested and the core volume of the cable core to be tested respectively by using an equivalent volume replacement method;

[0153] The length measurement module is used to measure the length of the cable core to be tested to form the cable length;

[0154] The second volume measurement module is used to measure the volume of the tape to form the tape volume;

[0155] The cross-sectional area calculation module is used to calculate the cross-sectional area of the cable through which the flow passes based on the total volume of the sample, the volume of the tape and the length of the cable;

[0156] The compression coefficient calculation module is used to calculate the compression coefficient based on the cross-sectional area of the current-carrying cable and the structural parameters of the cable core to be tested;

[0157] The conductive cross-sectional ratio calculation module is used to calculate the conductive cross-sectional ratio based on the total volume of the sample, the volume of the wire core and the volume of the tape;

[0158] The DC resistance coefficient calculation module is used to calculate the DC resistance coefficient based on the nominal cross-sectional area of the cable core to be tested and the cross-sectional area of the current-carrying cable;

[0159] The flow efficiency detection module detects the cable core flow efficiency of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient.

[0160] It can be understood that the above-mentioned device embodiment corresponds to the method embodiment of the present invention, which can implement the cable core flow efficiency detection method provided by any of the above-mentioned method embodiments of the present invention.

[0161] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. Furthermore, in the drawings of the device embodiments provided by the present invention, the connection relationship between modules indicates that they have a communication connection, which may be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement the present invention without inventive effort.

[0162] The specific embodiments described above further illustrate the objectives, technical solutions, 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 detecting the flow efficiency of a cable core, characterized in that: include: Obtain a cable sample to be tested; wherein the cable sample to be tested includes a cable segment to be tested and a tape wrapping the cable segment; the cable segment includes a cable core to be tested and an outer insulation layer wrapping the cable core to be tested; Using an equivalent volume replacement method, the total sample volume of the cable sample to be tested and the core volume of the cable core to be tested are measured respectively; Measuring the length of the cable core to be tested to obtain the cable length; measuring the volume of the tape to form a tape volume; Calculating the cross-sectional area of the cable through which the flow passes based on the total volume of the sample, the volume of the tape, and the length of the cable; Calculating a compression coefficient based on the cross-sectional area of the current-carrying cable and the structural parameters of the cable core to be tested; Calculating a conductive cross-sectional area ratio based on the total volume of the sample, the volume of the wire core, and the volume of the tape; Calculating the DC resistance coefficient based on the nominal cross-sectional area of the cable core to be tested and the cross-sectional area of the current-carrying cable; The cable core current flow efficiency of the cable sample to be tested is detected according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient.

2. The cable core flow efficiency detection method according to claim 1, characterized in that: The calculating the cross-sectional area of the cable through which the flow passes based on the total volume of the sample, the volume of the tape and the length of the cable comprises: The volume of the cable segment is obtained by subtracting the volume of the tape from the total sample volume of the cable sample to be tested: Based on the cable segment volume and the cable length, the following formula is used to calculate the cable cross-sectional area of the cable core to be tested: Where S1 is the cross-sectional area of the cable; V4 is the volume of the cable segment; L e is the cable length.

3. The cable core flow efficiency detection method according to claim 2, characterized in that: The calculating of the compression coefficient based on the cross-sectional area of the current-carrying cable and the structural parameters of the cable core to be tested includes: Obtaining structural parameters of the cable core to be tested; wherein the structural parameters include the number of single core wires and the cross-sectional area of the single core wires; Calculating a compression coefficient based on the cross-sectional area of the current-carrying cable, the number of single-wire cores, and the cross-sectional area of the single-wire cores; Where K s is the compression coefficient; S1 is the cross-sectional area of the current-carrying cable; n is the number of single core wires; S l It is the cross-sectional area of a single wire core.

4. The cable core flow efficiency detection method according to claim 3, characterized in that: The calculating the conductive cross-section ratio based on the total volume of the sample, the volume of the wire core, and the volume of the tape includes: Where K c is the conductive cross-section ratio; V2 is the core volume; V1 is the total volume of the sample; V3 is the tape volume.

5. The method for detecting the flow efficiency of a cable core according to claim 4, wherein: The calculating of the DC resistance coefficient based on the nominal cross-sectional area of the cable core to be tested and the cross-sectional area of the current-carrying cable comprises: Where, ε r is the DC resistance coefficient; S0 is the nominal cross-sectional area; S1 is the cross-sectional area of the current-carrying cable.

6. The method for detecting the flow efficiency of a cable core according to claim 5, characterized in that: The detecting the cable core current flow efficiency of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient comprises: Based on the compression coefficient and the conductive cross-section ratio, determining whether the cable sample to be tested meets a preset first conductive performance condition; Determining whether the cable sample to be tested meets a preset second conductivity performance condition based on the DC resistance coefficient; When the cable sample to be tested meets both the preset first conductivity performance condition and the preset second conductivity performance condition, it is determined that the cable core flow efficiency of the cable sample to be tested meets the standard; otherwise, it is determined that the cable core flow efficiency of the cable sample to be tested does not meet the standard.

7. The method for detecting the flow efficiency of a cable core according to claim 6, wherein: The determining, based on the compression coefficient and the conductive cross-section ratio, whether the cable sample to be tested meets a preset first conductive performance condition includes: Obtaining the compression coefficient threshold and the conductive cross-section ratio threshold; When the compression coefficient is greater than the compression coefficient threshold or the conductive cross-section ratio is greater than the conductive cross-section ratio threshold, it is determined that the cable sample to be tested meets the preset first conductive performance condition.

8. The method for detecting the flow efficiency of a cable core according to claim 6, wherein: The determining whether the cable sample to be tested meets a preset second conductivity performance condition based on the DC resistance coefficient includes: Get the DC resistance coefficient threshold; When the DC resistance coefficient is less than the DC resistance coefficient threshold, it is determined that the cable sample to be tested meets the preset second conductive performance condition.

9. The method for detecting the flow efficiency of a cable core according to claim 1, wherein: After detecting the cable core current flow efficiency of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient, the method further includes: Based on the cable length and the core volume, the conductor cross-sectional area of the cable core to be tested is calculated using the following formula: Where S2 is the conductor cross-sectional area; V2 is the core volume; L e is the cable length; Obtain the mass and density of the cable core to be tested, and calculate the verification volume of the cable core to be tested using the following formula; Where V5 is the verification volume of the cable core to be tested; m is the mass of the cable core to be tested; ρ is the density of the cable core to be tested; Based on the verification volume and the cable length, the verification area of the cable core to be tested is calculated using the following formula; Where S3 is the verification area of the cable core to be tested; V5 is the verification volume of the cable core to be tested; L e is the cable length; Based on the conductor cross-sectional area and the verification area, the error coefficient is calculated using the following formula; Where θ is the error coefficient; S2 is the conductor cross-sectional area; S3 is the verification area of the cable core to be tested; Based on the error coefficient, the current flow efficiency of the cable core is verified.

10. A cable core flow efficiency detection device, characterized in that: include: Sample acquisition module, first volume measurement module, length measurement module, second volume measurement module, cross-sectional area calculation module, compression coefficient calculation module, conductive cross-sectional ratio calculation module, DC resistivity calculation module and flow efficiency detection module; The sample acquisition module is used to obtain a cable sample to be tested; wherein the cable sample to be tested includes a cable segment to be tested and a tape wrapping the cable segment; the cable segment includes a cable core to be tested and an outer insulation layer wrapping the cable core to be tested; The first volume measurement module is used to measure the total sample volume of the cable sample to be tested and the core volume of the cable core to be tested respectively by using an equivalent volume replacement method; The length measurement module is used to measure the length of the cable core to be tested to form the cable length; The second volume measurement module is used to measure the volume of the tape to form the tape volume; The cross-sectional area calculation module is used to calculate the cross-sectional area of the cable through which the flow passes based on the total volume of the sample, the volume of the tape and the length of the cable; The compression coefficient calculation module is used to calculate the compression coefficient based on the cross-sectional area of the current-carrying cable and the structural parameters of the cable core to be tested; The conductive cross-sectional ratio calculation module is used to calculate the conductive cross-sectional ratio based on the total volume of the sample, the volume of the wire core and the volume of the tape; The DC resistance coefficient calculation module is used to calculate the DC resistance coefficient based on the nominal cross-sectional area of the cable core to be tested and the cross-sectional area of the current-carrying cable; The flow efficiency detection module detects the cable core flow efficiency of the cable sample to be tested according to the compression coefficient, the conductive cross-section ratio and the DC resistance coefficient.

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