CN103644884B - Based on thermometric power cable connector job specfication detection method - Google Patents

Abstract

The invention relates to the field of standard detection of power cable joint construction, and in particular to a method for standard detection of power cable joint construction based on temperature measurement. By arranging the temperature measurement lattice of the cable joint, the sensors with a certain accuracy can measure each Point temperature, to obtain the temperature distribution on the surface of the cable joint, and then calculate the correlation coefficients that characterize the uniformity of the temperature distribution of each section, such as the relative deviation of the temperature measurement point temperature at the boundary of each section, and the k-order error norm. These coefficients are obtained based on simulation calculations or experience In relation to the quality of the cable joint construction process, the present invention can not only judge the defects of the cable joint from the standardization of the construction process by detecting the temperature distribution of the cable joint, but also provide a reference for its service life prediction, and the detection process is simple , the amount of calculation is small, and the practicability is strong.

Description

Based on thermometric power cable connector job specfication detection method

Technical field

The present invention relates to a kind of power cable connector job specfication detection field, particularly a kind of based on thermometric electric powerCable connector job specfication detection method.

Background technology

Twisted polyethylene cable is widely used in transmission line of electricity with its excellent performance, but cable making length generally existsBelow 1000m, need cable connector stube cable. Cable connector is the important accessory of power cable, is also whole cableThe weak link on road. In recent years research shows, along with the progressively raising of cable body quality, and the thing that various cable connectors causeTherefore the ratio in power cable accident constantly rises, more than 50% accident occurs on cable connector. Due to cable connector systemMake flow process complexity, technological requirement is high. The manufacture craft that causes cable connector lack of standardization of construction is difficult to reach requirement, is cableOverheated burning, breakdown accident that joint causes have been buried hidden danger, often cause huge economic loss, and its processing quality becomesAffect the key factor of cable run safe operation. Need to detect in time in early days its defective workmanship, get rid of hidden danger.

Construct lack of standardization as: not to cable fully align, cable core cutting is insufficient, major insulation cutting is insufficientLarger Deng bent gap after all can causing being inserted in tube connector, tend to curved incline and enter being inserted in after prefabricated insulating part its cable coreAnd it is eccentric. Cable core is as cable thermal source, because joint cable core bias causes cable thermal source generation radial deflection, and can be to temperature fieldRadial distribution exerts an influence, and particularly the uniformity coefficient of cable surface Temperature Distribution can be affected.

Is at present all single temperature detection to the fault detect of cable connector, while detection, being only concerned about whether its temperature exceedes facesBoundary's threshold value, and do not detect its actual temp distribution situation. This monitoring mode can only go out after cable connector moves a period of timeWhen existing failure symptom, play certain alarm function, and can not at the beginning of cable connector operation, from its processing quality, lack cableFall into and detect judge. By the detection that temperature of cable junction is distributed can be from the source of cable fault, i.e. construction technologyDefect situation to cable connector in normalization is passed judgment on, and provides reference for life forecast from now on.

Summary of the invention

According to above the deficiencies in the prior art, the technical problem to be solved in the present invention is: provide one can overcome above-mentioned defect,Detect simply, amount of calculation is little, can determine cable connector construction technology standardized degree based on thermometric power cable connectorJob specfication detection method.

The technical solution adopted for the present invention to solve the technical problems is:

Described based on thermometric power cable connector job specfication detection method, it is characterized in that comprising the following steps:

Step 1: get m cross section on cable connector, get n point for measuring temperature in each cross-sectional boundaries. And measure eachThe temperature of point for measuring temperature, each point temperature T_(i,j)Represent, wherein i represents got cross section numbering 1≤i≤m, and j represents single sectionThe borderline point for measuring temperature numbering of face 1≤j≤n, wherein claims that on different cross section, numbering identical point for measuring temperature is similar point for measuring temperature;

Step 2: calculate the coefficient correlation that can characterize each cross sectional boundary uniformity of temperature profile degree:

1) calculate the mean temperature of each single cross section point for measuring temperature:

$T_{(i,\mathrm{avg})}=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{T}_{(i,j)}$

2) calculate the relative deviation of the each point for measuring temperature in single cross section:

e_(i,j)=(T_(i,j)/T_(i,avg)-1)*100%

Step 3, distributes according to the relative deviation of the similar point for measuring temperature in each cross section, i.e. e in the time that i changes from 1～m_(i,j)Situation of change,Use corresponding analytical method, obtain the eccentric situation of cable core, and set up evaluation criterion.

Described passes through to arrange cable connector thermometric dot matrix based on thermometric power cable connector job specfication detection method,Reach necessarily required sensor by precision and measure each point temperature, obtain the Temperature Distribution situation on cable connector surface, Jin ErjiCalculate and characterize each section temperature and be evenly distributed the coefficient correlation of degree as the relative deviation of each cross sectional boundary point for measuring temperature temperature, k rank errorNorm, obtains the relation of these coefficients and cable connector construction technology quality according to simulation calculation or experience, and executes for cable connectorThe grading of work Process Planning plasticity, the service life and the operation conditions that finally can be cable connector estimate to provide reference, whole process detectsSimply, amount of calculation is little.

Preferred further, the point for measuring temperature on the same cross section described in step 1 is uniformly distributed as far as possible, the similar survey of different cross sectionWarm spot is arranged on the same azimuth of the cylindrical-coordinate system taking cable axle center as axle.

Preferred further, each point temperature T in step 1_(i,j)Certainty of measurement at least to reach T_(i,j)Peaked 0.01%.

Preferred further, the analytical method in step 3 comprises k rank error norm analytic approach, and the method concrete steps are:

A asks for e_(i,j)K rank error norm average:

$M_{k,\mathrm{avg}}=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}\frac{1}{m}\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{|e_{(i,j)}-e_{(\mathrm{avg},j)}|}^k$

B sets up processing quality evaluation criterion, and e is set_(i,j)K rank error norm threshold value M_k,g(g=1,2 ... G), wherein G is workSkill credit rating number, g value is larger, shows that processing quality is poorer;

If C judges M_k,avg<M_k,gThis cable connector construction technology credit rating is g.

The beneficial effect that the present invention has is:

Described based on thermometric power cable connector job specfication detection method not only detected temperatures whether exceed criticalThreshold value, and detect the distribution situation of its actual temp. Described monitoring method both can be moved a period of time at cable connectorAfter play certain alarm function while breaking down sign, and can also be right from its processing quality at the beginning of cable connector operationElectric cable stoppage detects judge. The present invention can be from the source of cable fault by the detection that temperature of cable junction is distributed,Be in the normalization of construction technology, the defect situation of cable connector to be passed judgment on, and can provide ginseng for its life forecastExamine, testing process is simple, and amount of calculation is little, practical.

Brief description of the drawings

Fig. 1 is that cable connector testing temperature point of the present invention arranges schematic diagram;

Fig. 2 is the not temperature field distributed simulation figure of eccentric cross section of cable connector of the present invention;

Fig. 3 is the temperature field distributed simulation figure of cable connector eccentric cross section of the present invention;

Fig. 4 is the surface temperature Changing Pattern in the different eccentric degrees of cable connector of the present invention cross section;

Fig. 5 is that cable connector of the present invention cross section is the highest with the different surface of eccentric degree, minimum temperature change curve;

Wherein, 1, point for measuring temperature; 2, cross section.

Detailed description of the invention

Below in conjunction with accompanying drawing, embodiments of the invention are described further:

As shown in Figure 1, of the present invention based on thermometric power cable connector job specfication detection method, comprise followingStep:

Step 1: get m cross section 2 on cable connector, get n point for measuring temperature 1 in each cross-sectional boundaries. And measure eachThe temperature of individual point for measuring temperature 1, each point temperature T_(i,j)Represent, wherein i represents got cross section numbering 1≤i≤m, and j represents listPoint for measuring temperature numbering 1≤j≤n in individual cross sectional boundary, wherein claims to number identical point for measuring temperature 1 for similar point for measuring temperature on different cross section;

Step 2: calculate the coefficient correlation that can characterize each cross sectional boundary uniformity of temperature profile degree:

1) calculate the mean temperature of each single cross section point for measuring temperature 1:

$T_{(i,\mathrm{avg})}=\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{T}_{(i,j)}$

2) calculate the relative deviation of the each point for measuring temperature 1 in single cross section:

e_(i,j)=(T_(i,j)/T_(i,avg)-1)*100%

Step 3, distributes according to the relative deviation of the similar point for measuring temperature in each cross section, i.e. e in the time that i changes from 1～m_(i,_j)Situation of change,Use corresponding analytical method, obtain the eccentric situation of cable core, and set up evaluation criterion.

Wherein, the point for measuring temperature 1 on the same cross section described in above-mentioned steps one is uniformly distributed as far as possible, the similar survey of different cross sectionWarm spot is arranged on the same azimuth of the cylindrical-coordinate system taking cable axle center as axle, each point temperature T_(i,j)Certainty of measurement at least wantReach T_(i,j)Peaked 0.01%.

Analytical method in described step 3 comprises k rank error norm analytic approach, and the method concrete steps are:

A asks for e_(i,j)K rank error norm average:

$M_{k,\mathrm{avg}}=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}\frac{1}{m}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{|e_{(i,j)}-e_{(\mathrm{avg},j)}|}^k$

B sets up processing quality evaluation criterion, and e is set_(i,j)K rank error norm threshold value M_k,g(g=1,2 ... G), wherein G is workSkill credit rating number, g value is larger, shows that processing quality is poorer;

If C judges M_k,avg<M_k,gThis cable connector construction technology credit rating is g.

Embodiment:

As shown in Figure 1, set up cylindrical-coordinate system as axle by right-hand screw rule taking cable axis, establish the orientation of cable minimum pointφ=0, angle. On cable connector, from left to right get 5 cross sections 2, in each cross-sectional boundaries, exist respectively、π/3、2π/3、Six points for measuring temperature are got at π, 4 π/3,5 π/3 places.

Measure the temperature T of each point for measuring temperature_(i,j), conventional temperature-sensing element mainly contains infrared thermometer, thermocouple, heat at presentResistance, semiconductor PN, Thermothy ristor and integrated circuit type temperature sensor etc. are several, and wherein concrete thermometric form is notFixed, only require each point temperature T_(i,j)Certainty of measurement at least to reach T_(i,j)Peaked 0.01%.

Calculate the mean temperature of each single cross section point for measuring temperature:

$T_{(i,\mathrm{avg})}=\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{T}_{(i,j)}$

Calculate the relative deviation of the each point for measuring temperature in single cross section:

e_(i,j)=(T_(i,j)/T_(i,avg)-1)*100%

Ask for e_(i,j)1 rank error norm average:

$M_{k,\mathrm{avg}}=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}\frac{1}{m}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}|e_{(i,j)}-e_{(\mathrm{avg},j)}|$

Set up processing quality evaluation criterion, e is set_(i,j)1 rank error norm threshold value M_1,g(g=1,2 ... G). If wireline environment weekEnclose medium coefficient of heat transfer even, the simulation scenarios that the temperature field of the not eccentric and eccentric cross section of its joint distributes is respectively as Fig. 2,3Show. As shown in Figure 4, the each cross section of joint is along with bias for the circumferential surface temperature changing regularity in the different cross section of joint eccentric degreeIts surperficial maximum temperature that degree is different and minimum temperature change curve are as shown in Figure 5. According to simulation analysis by processing qualityBe divided into the respectively corresponding following several threshold value M of 5 grades_1,1=0.015%、M_1,2=0.03%、M_1,3=0.045%、M_1,4=0.055%、M_1,5=0.07%. Wherein 5 grades represent respectively opposing tabs end, joint center (joint end is not eccentric), cableCore eccentric distance is less than 2,4,6,8,10mm.

If judgement M_1,avg<M_1,gThis cable connector construction technology credit rating is g.

The present invention, by arranging cable connector thermometric dot matrix, reaches necessarily required sensor by precision and measures each point temperature,Obtain the Temperature Distribution situation on cable connector surface, and then the be evenly distributed coefficient correlation of degree of each section temperature of computational representationAs the relative deviation of each cross sectional boundary point for measuring temperature temperature, k rank error norm, according to simulation calculation or experience obtain these coefficients withThe relation of cable connector construction technology quality, and be the normative grading of cable connector construction technology, finally can be cable connectorService life and operation conditions estimate to provide reference, and whole process detects simple, and amount of calculation is little.

Claims (4)

1. based on a thermometric power cable connector job specfication detection method, it is characterized in that comprising the following steps:

Step 1: get m cross section on cable connector, get n point for measuring temperature in each cross-sectional boundaries, and measure eachThe temperature of point for measuring temperature, each point temperature T_(i,j)Represent, wherein i represents got cross section numbering 1≤i≤m, and j represents singlePoint for measuring temperature numbering 1≤j≤n in cross sectional boundary, wherein claims that on different cross section, numbering identical point for measuring temperature is similar point for measuring temperature;

Step 2: calculate the coefficient correlation that can characterize each cross sectional boundary uniformity of temperature profile degree:

1) calculate the mean temperature of each single cross section point for measuring temperature:

$T_{(i,avg)}=\underset{j=1}{\overset{n}{\&Sigma;}}{T}_{(i,j)}$

2) calculate the relative deviation of the each point for measuring temperature in single cross section:

e_(i,j)＝(T_(i,j)/T_(i,avg)-1)*100％

Step 3, distributes according to the relative deviation of the similar point for measuring temperature in each cross section, i.e. e in the time that i changes from 1～m_(i,j)Situation of change,Use corresponding analytical method, obtain the eccentric situation of cable core, and set up evaluation criterion.

2. according to claim 1 based on thermometric power cable connector job specfication detection method, its feature existsIn: the point for measuring temperature on the each cross section described in described step 1 is uniformly distributed, and the similar point for measuring temperature of different cross section is arranged onOn the same azimuth of the cylindrical-coordinate system taking cable axle center as axle.

3. according to claim 1 based on thermometric power cable connector job specfication detection method, its featureBe: each point temperature T in described step 1_(i,j)Certainty of measurement at least to reach T_(i,j)Peaked 0.01%.

4. according to claim 1 based on thermometric power cable connector job specfication detection method, its featureBe: the analytical method in described step 3 comprises k rank error norm analytic approach, and the method concrete steps are:

A asks for e_(i,j)K rank error norm average:

$M_{k,avg}=\frac{1}{n}\underset{j=1}{\overset{n}{\&Sigma;}}\frac{1}{m}\underset{i=1}{\overset{m}{\&Sigma;}}|e_{(i,j)}-e_{(avg,j)}{|}^k$

B sets up processing quality evaluation criterion, and e is set_(i,j)K rank error norm threshold value M_k,g(g=1,2 ... G), wherein G is workSkill credit rating number, g value is larger, shows that processing quality is poorer;

If C judges M_k,avg＜M_k,gThis cable connector construction technology credit rating is g.