A transmission line tension clamp state detection device and method

Abstract

The present invention provides a transmission line tension clamp state detection device and method, the device comprises a first clamp, a second clamp, a third clamp, and a fourth clamp; wherein the first clamp and the fourth clamp are clamp-shaped test clamps for clamping conductors, and the second clamp and the third clamp are flat-plate test clamps for clamping tension clamps; the conductor and the tension clamp between the first clamp and the second clamp constitute a first measurement section, the tension clamp between the second clamp and the third clamp constitute a second measurement section, and the conductor and the tension clamp between the third clamp and the fourth clamp constitute a third measurement section. The present invention can detect abnormal conductivity at the overlap due to factors such as poor installation process and surface oxidation during the power outage overlap process or at a subsequent stage when the power outage is still in progress, thereby effectively reducing unplanned line outages.

Description

Technical Field

[0001] The invention belongs to the field of power transmission line monitoring, and in particular relates to a transmission line tension clamp state detection device and method. Background Art

[0002] Transmission lines are an important part of the power system. Whether the tension clamp connection is reliable and whether the conductivity is good is of great significance to the effective transmission of electric energy. In actual operation of the line, the line is often heated due to poor conductivity, and this problem often occurs at the overlap. There are generally the following reasons for poor conductivity at the overlap: First, reasonable conductor materials and cross-sectional areas are not selected when the lines are overlapped; second, the flatness of the line overlap is not ideal; third, the surface treatment of the line overlap is improper or the connecting bolts are loose. If the connection conductivity is poor, heat will occur during the operation of the line. As the operating time increases, the conductivity of the line overlap may further deteriorate, and may even break due to overheating or electrodynamic force, posing a threat to the safe operation of the power grid.

[0003] At present, conventional detection methods include using infrared temperature measurement and other technical means to detect this heating phenomenon, and then apply for power outages for maintenance or live work to eliminate defects. Although this method can eliminate defects, it will still lead to unplanned power outages or deactivation of reclosing devices, which brings burdens and uncertain risks to the safe operation of the power grid. In addition, there are also X-ray flaw detection methods and ultrasonic detection for transmission line status monitoring. The disadvantage of X-ray flaw detection is that some abnormalities do not manifest as heating, which poses less threat to line operation. At the same time, some wire clamps heat up without internal abnormalities, which cannot be identified by X-rays, and the detection time is too long. Ultrasonic detection has similar shortcomings to X-ray flaw detection, and the detection time is longer.

[0004] The existing technology is unable to detect abnormal conductivity at the splicing point during the power outage splicing process or at a subsequent stage while still in the power outage stage, is unable to reduce unplanned outages, and has low work efficiency. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a transmission line tension clamp state detection device and method. The device comprises a first clamp, a second clamp, a third clamp, and a fourth clamp; wherein the first clamp and the fourth clamp are clamp-shaped test clamps for clamping conductors, and the second clamp and the third clamp are flat-plate test clamps for clamping tension clamps; the conductor and the tension clamp between the first clamp and the second clamp constitute a first measurement section, the tension clamp between the second clamp and the third clamp constitute a second measurement section, and the conductor and the tension clamp between the third clamp and the fourth clamp constitute a third measurement section; the resistance of the three measurement sections is measured respectively by a resistance measuring device to obtain a first resistance R1, a second resistance R2, and a third resistance R3; the conductivity and consistency of the tension clamp are detected according to R1, R2, and R3.

[0006] The present invention adopts the following technical solution.

[0007] A transmission line tension clamp state detection device comprises a resistance measuring device, and further comprises: a first clamp, a second clamp, a third clamp, and a fourth clamp; wherein the first clamp and the fourth clamp are clamp-shaped test clamps for clamping a conductor, and the second clamp and the third clamp are flat-plate test clamps for clamping a tension clamp; the conductor and the tension clamp located between the first clamp and the second clamp constitute a first measuring section, the tension clamp located between the second clamp and the third clamp constitutes a second measuring section, and the conductor and the tension clamp located between the third clamp and the fourth clamp constitute a third measuring section;

[0008] The resistances of the three measuring sections are measured respectively by using a resistance measuring device to obtain a first resistance R1, a second resistance R2 and a third resistance R3; the conductivity and consistency of the tension clamp are detected according to R1, R2 and R3.

[0009] A method for detecting the state of a transmission line tension clamp includes a conductivity criterion and a consistency criterion. The conductivity criterion is used to determine the conduction state of the transmission line tension clamp, and to determine whether the contact between the overlap and the crimp is sufficient, that is, whether the resistance of the tension clamp is less than the resistance of the conductor of the same length, or whether the resistance of the tension clamp crimp per unit length is less than the resistance of the conductor per unit length, or whether the resistance of the tension clamp overlap per unit length is less than 2.2 times the resistance of the conductor per unit length and the resistance of the tension clamp overlap is less than a fixed value; the consistency criterion is used to determine whether there is excessive local resistance at two crimps and one overlap of the transmission line tension clamp, that is, whether the resistance of the second measurement section of each phase ABC is less than 2.2 times the resistance of the conductor per unit length and the resistance of the tension clamp overlap is less than a fixed value, or whether the three-phase unbalance index is less than 1 / 3.

[0010] Preferably, the conductivity criterion includes criterion 1, criterion 2, and criterion 3, which are respectively:

[0011]

[0012] Where Ri is the resistance of the crimping joint measured by each section of the state discrimination device, is the unit length impedance of each segment, It is the unit impedance of a conductor of the same length as the tension clamp.

[0013] Preferably, the consistency criteria include criterion 4 and criterion 5 respectively:

[0014]

[0015] In the formula, is the resistance per unit length of the second measuring section of phase A, is the resistance per unit length of the second measuring section of phase B, is the resistance per unit length of the second measuring section of phase C, U AB is the AB phase imbalance index, U BC is the BC phase imbalance index, U CA is the CA phase imbalance index, U ABC is the three-phase unbalance index, It is the unit impedance of a conductor of the same length as the tension clamp.

[0016] Preferably, during the infrastructure acceptance, after the tension clamp is crimped and overlapped, check criteria 1, 2 and 3. When criteria 1, 2 and 3 are met at the same time, the tension clamp is judged to be in a conductive state and accepted; if criterion 1 is qualified and criterion 2 is unqualified, check whether there are defects at the crimping; if criterion 1 and criterion 2 are qualified and criterion 3 is unqualified, check whether there are defects at the overlap, and at this time, loosen the bolts at the overlap for surface treatment and then retighten the bolts.

[0017] Preferably, when a power outage is performed to eliminate the fault, infrared temperature measurement is first performed to confirm the heating location; after the power outage, criterion 1, criterion 2 and criterion 3 are checked; when criterion 1, criterion 2 and criterion 3 are met at the same time, the wire clamp is checked for non-resistance heating; if criterion 1 is qualified and criterion 2 is unqualified, check whether there are defects in the crimping; if criterion 1 and criterion 2 are qualified and criterion 3 is unqualified, check whether there are defects in the overlap, and at this time, loosen the bolts at the overlap for surface treatment and then retighten the bolts.

[0018] Preferably, when eliminating faults under power, first perform infrared temperature measurement to further confirm the heating location; check criteria 1, 2 and 3; when criteria 1, 2 and 3 are met at the same time, focus on checking whether the wire clamp has non-resistance heating; if criterion 1 is qualified and criterion 2 is unqualified, check whether there are defects in the crimping; if criteria 1 and criterion 2 are qualified and criterion 3 is unqualified, check whether there are defects in the overlap.

[0019] Preferably, during the infrastructure acceptance, after the tension clamp is crimped and overlapped, the phase separation form criterion 4 and criterion 5 are checked. When both criterion 4 and criterion 5 are met at the same time, the tension clamp is judged to be in a qualified consistency state and the acceptance is qualified; if criterion 4 is qualified and criterion 5 is unqualified, it is necessary to further check whether there are defects at the overlap.

[0020] Preferably, when power outage is performed to eliminate the inconsistent temperature rise, infrared temperature measurement is first performed to further confirm the heating location; after the power outage, the phase separation form criterion 4 and criterion 5 are checked. When both criterion 4 and criterion 5 are met at the same time, it is judged that the consistency state of the tension clamp is qualified, and the focus is on checking whether the clamp has non-resistance heating; if criterion 4 is qualified and criterion 5 is unqualified, it is necessary to further check whether there are defects in the overlap.

[0021] Preferably, for live fault elimination with inconsistent temperature rise, infrared temperature measurement is first performed to further confirm the heating location; when both criteria 4 and 5 are met at the same time, it is judged that the consistency state of the tension clamp is qualified, and the focus is on checking whether the clamp has non-resistance heating; if criteria 4 is qualified and criteria 5 is unqualified, it is necessary to further check whether there are defects in the overlap.

[0022] The beneficial effect of the present invention is that, compared with the prior art,

[0023] The present invention can detect abnormal conductivity at the splicing point caused by poor installation technology, surface oxidation and other factors during the power outage splicing process or at a subsequent stage while still in the power outage stage, effectively reducing unplanned shutdowns of the line. At the same time, the post-control method of infrared temperature measurement + power outage maintenance is converted into in-process control for directly discovering abnormalities and handling them in a timely manner during the power outage work, which can greatly improve work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a micro-ohm resistance measuring device of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only embodiments of a part of the present invention, rather than all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0026] like Figure 1As shown, a transmission line tension clamp state detection device is provided with four test clamps. Positions S1 and S4 are equipped with arc-shaped clamp-like test clamps for clamping the conductor part of the transmission line; positions S2 and S3 are equipped with slightly arc-shaped flat plate-shaped test clamps for clamping the flat part of the tension clamp.

[0027] The resistance R1 of the crimping point is measured at (S1, S2), the resistance R2 of the overlapping point is measured at (S2, S3), and the resistance R3 of the crimping point is measured at (S3, S4). The length of three segments, is the unit length impedance of the three segments.

[0028] A method for detecting the conductivity and consistency status of a transmission line tension clamp includes a conductivity criterion and a consistency criterion.

[0029] Conductivity: refers to the smoothness of current flow. Roughly speaking, the smaller the resistance, the better the conductivity. In practical applications, when the resistance is small to a certain extent, such as a value below 5 micro-ohms, the conductivity is considered to be very good.

[0030] Consistency: A measure of the differences between several parts. The closer the resistance of each part (resistance per unit length) is, the better the consistency is considered.

[0031] The continuity criterion is:

[0032] Assume that the resistance value of the wire with the same length as the tension clamp is R l , its length l = l1 + l2 + l3, and the unit impedance is Then there is judgment 1: That is:

[0033] Considering that the width of the wire clamp is wider than that of ordinary conductors, generally qualified tension clamps meet the following requirements: Under the premise that the total resistance of the wire clamp is less than the resistance of the conductor, there may be excessive resistance in some parts. Therefore, criteria 2 and 3 are added:

[0034]

[0035] When criteria 1, 2 and 3 are met at the same time, the conductive state of the tension clamp is judged to be qualified.

[0036] The consistency criterion is:

[0037] The problem of excessive temperature difference caused by three-phase resistance difference often occurs at the overlap of tension clamps at corresponding positions of different phases of transmission lines. Therefore, a resistance consistency criterion for assessing the resistance-type heating occurring at the overlap is proposed.

[0038] Improved criterion 4 for the continuity criterion that the three-phase tension clamp needs to meet:

[0039]

[0040] In the formula, is the resistance per unit length of the second measuring section of phase A, is the resistance per unit length of the second measuring section of phase B, is the resistance per unit length of the second measurement section of phase C.

[0041] Define consistency index: U ABC =max(U AB , U BC , U CA )

[0042] Criterion 5 is:

[0043] in

[0044] In the formula, R A is the resistance of the measured conductor of phase A (the sum of three sections); R B is the resistance of the measured conductor of phase B (the sum of three sections); R C is the resistance of the C-phase conductor under test (the sum of three sections).

[0045] In particular, R. A =R B =R C When there is U ABC =0.

[0046] Criterion 5 can characterize the asymmetry of the resistance at the overlap of the tension clamp. The higher the asymmetry, the higher the corresponding U ABC The higher the value, the lower it is.

[0047] Example 1: The conductivity criterion is applied to infrastructure acceptance.

[0048] After the tension clamp is crimped and overlapped, use a micro-ohm resistance measuring device to check criteria 1, 2 and 3. When criteria 1, 2 and 3 are met at the same time, the tension clamp is judged to be in a qualified state of conduction and accepted. If criterion 1 is qualified and criterion 2 is unqualified, check whether there are defects at the crimping. If criterion 1 and criterion 2 are qualified and criterion 3 is unqualified, check whether there are defects at the overlap (untighten the bolts at the overlap for surface treatment and then tighten the bolts).

[0049] Embodiment 2: The continuity criterion is applied to operation fault elimination.

[0050] 1) Power outage and fault elimination:

[0051] Before power outage to eliminate faults, first perform infrared temperature measurement to confirm the heating location. After power outage, use a micro-ohm resistance measuring device to check criteria 1, 2, and 3. When criteria 1, 2, and 3 are met at the same time, focus on checking whether the wire clamp has the possibility of non-resistance heating (such as eddy currents caused by manufacturing defects, etc.). If criteria 1 is qualified and criteria 2 is unqualified, check whether there are defects in the crimping. If criteria 1 and criteria 2 are qualified and criteria 3 is unqualified, check whether there are defects in the overlap (untighten the bolts at the overlap for surface treatment and then tighten the bolts).

[0052] 2) Live fault elimination:

[0053] Before eliminating the fault, first perform infrared temperature measurement to further confirm the heating location. After the live personnel enter the live area, use a micro-ohm resistance measuring device (with live measurement function) to check criteria 1, 2 and 3. When criteria 1, 2 and 3 are met at the same time, focus on checking whether the wire clamp has the possibility of non-resistance heating (such as eddy current caused by manufacturing defects, etc.). If criterion 1 is qualified and criterion 2 is unqualified, check whether there are defects in the crimping. If criterion 1 and criterion 2 are qualified and criterion 3 is unqualified, check whether there are defects in the overlap (tighten the bolts again).

[0054] Embodiment 3: Application of consistency criteria to infrastructure acceptance.

[0055] After the tension clamp is crimped and overlapped, use a micro-ohm resistance measuring device to check criteria 4 (phase splitting form) and 5. When criteria 4 and 5 are met at the same time, the tension clamp is judged to be in a qualified consistency state and accepted. If criteria 4 is qualified and criteria 5 is unqualified, it is necessary to further check whether there are defects at the overlap (generally, check from the overlap of the clamp with a larger resistance).

[0056] Embodiment 4: The consistency criterion is applied to operation troubleshooting.

[0057] 1) Power outage and fault elimination due to inconsistent temperature rise:

[0058] Before power outage to eliminate faults, infrared temperature measurement is first performed to further confirm the heating location. After power outage, use a micro-ohm resistance measuring device to check criteria 4 (phase splitting) and 5. When criteria 4 and 5 are met at the same time, it is judged that the tension clamp consistency state is qualified, and the focus is on checking whether the clamp has non-resistance heating (such as eddy current caused by manufacturing defects, etc.). If criterion 4 is qualified and criterion 5 is unqualified, it is necessary to further check whether there are defects in the overlap (generally, the inspection is carried out from the overlap of the clamp with a larger resistance).

[0059] 2) Live fault elimination with inconsistent temperature rise:

[0060] Before troubleshooting, first perform infrared temperature measurement to further confirm the heating location. Use a micro-ohm resistance measuring device (with live measurement function) to check criteria 4 (phase splitting form) and 5. When criteria 4 and 5 are met at the same time, it is judged that the tension clamp consistency state is qualified, and the focus is on checking whether the clamp has non-resistance heating (such as eddy currents caused by manufacturing defects, etc.). If criteria 4 is qualified and criteria 5 is unqualified, it is necessary to further check whether there are defects in the overlap (generally, check from the overlap of the clamp with a larger resistance).

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for detecting the state of a transmission line tension clamp, using a transmission line tension clamp state detection device for detection, including a resistance measuring device, characterized in that: It also includes: a first wire clamp, a second wire clamp, a third wire clamp, and a fourth wire clamp; wherein the first wire clamp and the fourth wire clamp are clamp-shaped test clamps for clamping the conductor, and the second wire clamp and the third wire clamp are flat-plate test clamps for clamping the tension wire clamp; the conductor and the tension wire clamp located between the first wire clamp and the second wire clamp constitute a first measuring section, the tension wire clamp located between the second wire clamp and the third wire clamp constitutes a second measuring section, and the conductor and the tension wire clamp located between the third wire clamp and the fourth wire clamp constitute a third measuring section; The resistance of the three measuring sections is measured by a resistance measuring device to obtain a first resistance R1, a second resistance R2 and a third resistance R3; the conductivity and consistency of the tension clamp are detected according to R1, R2 and R3; The detection method includes a conductivity criterion and a consistency criterion. The conductivity criterion is used to determine the conduction state of the transmission line tension clamp and whether the contact between the overlap and the crimp is sufficient, that is, whether the resistance of the tension clamp is less than the resistance of the conductor of the same length, or whether the resistance of the tension clamp crimp per unit length is less than the resistance of the conductor per unit length, or whether the resistance of the tension clamp overlap per unit length is less than 2.2 times the resistance of the conductor per unit length and the resistance of the tension clamp overlap is less than a fixed value; the consistency criterion is used to determine whether there is excessive local resistance at two crimps and one overlap of the transmission line tension clamp, that is, whether the resistance of the second measuring section of each phase ABC is less than 2.2 times the resistance of the conductor per unit length and the resistance of the tension clamp overlap is less than a fixed value, or whether the three-phase unbalance index is less than 1 / 3; The conductivity criterion includes criterion 1, criterion 2, and criterion 3, which are respectively: In the formula, R i The resistance of the crimping joint measured by each section of the state judgment device, is the impedance per unit length of each segment, is the unit impedance of the conductor with the same length as the tension clamp, is the resistance value of the conductor with the same length as the tension clamp; The consistency criteria include criteria 4 and 5, which are: In the formula, is the resistance per unit length of the second measuring section of phase A, is the resistance per unit length of the second measuring section of phase B, is the resistance per unit length of the second measuring section of phase C, is the AB phase imbalance index, is the BC phase imbalance index, is the CA phase imbalance index, is the three-phase unbalance index, It is the unit impedance of a conductor of the same length as the tension clamp.

2. A method for detecting the state of a transmission line tension clamp according to claim 1, characterized in that: During the infrastructure acceptance, after the tension clamp is crimped and overlapped, check criteria 1, 2 and 3. When criteria 1, 2 and 3 are met at the same time, the tension clamp is judged to be in a qualified state of conduction and the acceptance is qualified; if criterion 1 is qualified and criterion 2 is unqualified, check whether there are defects at the crimping; if criteria 1 and 2 are qualified and criterion 3 is unqualified, check whether there are defects at the overlap, and at this time, loosen the bolts at the overlap for surface treatment and then retighten the bolts.

3. A method for detecting the state of a transmission line tension clamp according to claim 1, characterized in that: When power is cut off to eliminate faults, first perform infrared temperature measurement to confirm the heating point; after power outage, check criteria 1, 2 and 3; when criteria 1, 2 and 3 are met at the same time, check whether the wire clamp has non-resistance heating; if criteria 1 is qualified and 2 is unqualified, check whether there are defects in the crimping; if criteria 1 and 2 are qualified and 3 is unqualified, check whether there are defects in the overlap, at this time loosen the bolts at the overlap, perform surface treatment and then retighten the bolts.

4. A method for detecting the state of a transmission line tension clamp according to claim 1, characterized in that: When troubleshooting live, first perform infrared temperature measurement to further confirm the heating location; check criteria 1, 2 and 3; when criteria 1, 2 and 3 are met at the same time, focus on checking whether the wire clamp has non-resistance heating; if criterion 1 is qualified and criterion 2 is unqualified, check whether there are defects in the crimping; if criteria 1 and criterion 2 are qualified and criterion 3 is unqualified, check whether there are defects in the overlap.

5. A method for detecting the state of a transmission line tension clamp according to claim 1, characterized in that: During the infrastructure acceptance, after the tension clamp is crimped and overlapped, check the phase form criteria 4 and 5. When both criteria 4 and 5 are met at the same time, the tension clamp is judged to be in a qualified consistency state and the acceptance is qualified; if criterion 4 is qualified and criterion 5 is unqualified, it is necessary to further check whether there are defects in the overlap.

6. A method for detecting the state of a transmission line tension clamp according to claim 1, characterized in that: For power outages to eliminate faults caused by inconsistent temperature rise, first perform infrared temperature measurement to further confirm the heating location; after the power outage, check the phase separation form criteria 4 and 5. When both criteria 4 and 5 are met at the same time, it is judged that the consistency status of the tension clamp is qualified, and the focus is on checking whether the clamp has non-resistance heating; if criterion 4 is qualified and criterion 5 is unqualified, it is necessary to further check whether there are defects in the overlap.

7. A method for detecting the state of a transmission line tension clamp according to claim 1, characterized in that: For live fault elimination with inconsistent temperature rise, infrared temperature measurement shall be carried out first to further confirm the heating location; when both criteria 4 and 5 are met at the same time, it is judged that the consistency status of the tension clamp is qualified, and the focus is on checking whether the clamp has non-resistance heating; if criteria 4 is qualified and criteria 5 is unqualified, it is necessary to further check whether there are defects in the overlap.

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