CN108254659A - The shelf depreciation of cable and the combined detection system of leakage current and method under high direct voltage - Google Patents
The shelf depreciation of cable and the combined detection system of leakage current and method under high direct voltage Download PDFInfo
- Publication number
- CN108254659A CN108254659A CN201711418638.7A CN201711418638A CN108254659A CN 108254659 A CN108254659 A CN 108254659A CN 201711418638 A CN201711418638 A CN 201711418638A CN 108254659 A CN108254659 A CN 108254659A
- Authority
- CN
- China
- Prior art keywords
- cable
- leakage current
- evidence
- voltage
- partial discharge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
Abstract
The invention discloses the shelf depreciation of cable under a kind of high direct voltage and the combined detection system of leakage current, including：High voltage output device is used to export high voltage direct current, and the high-voltage output end of the High voltage output device and one end of cable connect；High precision electro flow table is serially connected on the ground wire of the cable, and the high precision electro flow table is used to detect leakage current；High Frequency Current Sensor, pincers are on the ground wire of the cable；Oscillograph is connect with the High Frequency Current Sensor, partial discharge pulse's signal of acquisition and storage High Frequency Current Sensor transmission；Detection branch is connected to including the detection capacitance being connected in series with and detection impedance, the detection branch between the ground terminal of the high-voltage output end of the High voltage output device and the ground wire of cable；Partial discharge detector, input terminal are connect with the detection impedance；Display terminal is connect with the output terminal of the Partial discharge detector.The invention also discloses associated detecting methods.
Description
Technical field
The present invention relates to a kind of detecting system and method more particularly to a kind of detection systems for direct current vertical compression power equipment
System and method.
Background technology
In recent years, the domestic and international DC power transmission line quantity that puts into operation is continuously increased, and voltage class is continuously improved, realized ±
" triple jump " of 160kV, ± 200kV, ± 320kV super-pressure flexible direct current cables.Crosslinked polyethylene (XLPE) is with its insulating properties
The advantage of the good and higher Long-term service temperature of energy becomes the first choice of direct current cables insulating materials.Although direct current cables technology is empty
Preceding development, but the insulation live detection of high voltage direct current (High Voltage Direct Current, HVDC) cable and attachment,
The O＆Ms such as fault diagnosis and signal post-processing technical research relatively lag behind.
Shelf depreciation (PD) is to lead to one of high voltage power cable insulation degradation and the principal mode of aging.The part of cable
It is closely related that discharge examination amount is insulated from situation, thus, partial discharge test for the evaluation of High Voltage XLPE Power Cable insulation status and
The best approach of Incipient Fault Diagnosis.
And leakage current refers to that core flows through major insulation to the electric current of metal sheath under high voltages, can reflect medium entirety
The situation made moist and integrally deteriorated.In general, insulating materials aging, D.C. resistance will certainly decline, and insulating materials is straight
Leakage resistance has good linear relationship with DC leakage-current.The experiment of leakage current is substantially phase with measuring insulation resistance
With, except that higher when the DirectCurrent Voltage Ratio being applied on sample measures insulation resistance.
In conclusion shelf depreciation and leakage current are the two ways that can characterize Electric Power Equipment Insulation performance.And
At this stage, it for high-voltage DC cable insulating detection operation or experimental study, is usually examined using respective detecting system
It surveys, but not about the system research or exploitation of shelf depreciation and leakage current joint-detection.
However, using based on single type information to the pattern-recognition of cable insulation state often there are one-sidedness because
Direct current XLPE cable leakage current and local discharge information, between the two with probabilistic interrelated.And by Dempster
The it is proposed and theory (hereinafter referred to as D-S evidence theory) that is improved by Shafer, the elementary tactics of the theory in 1967
It is exactly that independent judgment is carried out to proposition each in framework of identification respectively using two or more incoherent evident informations, then passes through
Combining evidences rule gets up the judging result fusion of multiple evidences, so as to obtain correct conclusion.By evidence theory fusion,
It can ensure that each evidence uncertainty present in mode identification procedure can weaken to greatest extent after fusion, thus from
Theoretically reduce the uncertainty of pattern-recognition.Since D-S evidence theory can more objectively respond the uncertainty of things,
It therefore, can by the data fusion detected if the system that can use shelf depreciation and leakage current joint-detection is detected
The information loss of single detection means of the prior art is reduced, so as to improve the property for the detecting system for possessing a variety of detection means
Energy.
Based on this, it is expected to obtain a kind of combined detection system and method, by the shelf depreciation of direct current high voltage cable and let out
Leakage current comprehensive detection system carries out effective integration to two types detection information using D-S evidence theory, builds Weighted Fusion
Identification system, so as to greatly improve detection and pattern-recognition sensitivity, overcome it is of the prior art use single type data
The insulation degradation or the situation of defect that can not be judged or judge by accident so that direct current height can effectively be detected using the associated detecting method
The state of cable is depressed, provides more objective testing result.
Invention content
An object of the present invention is to provide for the connection of the shelf depreciation of cable and leakage current under a kind of high direct voltage
Detecting system is closed, which can overcome the insulation degradation of the prior art that can not be judged or be judged by accident using single type data
Or the situation of defect so that the state of cable under high direct voltage can be effectively detected using the combined detection system, so as to meet
The actual needs at scene.
Based on above-mentioned purpose, the present invention proposes the shelf depreciation of cable and the joint of leakage current under a kind of high direct voltage
Detecting system, including：
High voltage output device is used to export high voltage direct current, the high-voltage output end and cable of the High voltage output device
One end connection；
High precision electro flow table is serially connected on the ground wire of the cable, and the high precision electro flow table leaks for detecting
Electric current；
High Frequency Current Sensor, pincers are on the ground wire of the cable；
Oscillograph is connect with the High Frequency Current Sensor, the office of acquisition and storage High Frequency Current Sensor transmission
Portion's discharge pulse signal；
Detection branch is connected to the height including the detection capacitance being connected in series with and detection impedance, the detection branch
Between the ground terminal of the high-voltage output end of pressure output device and the ground wire of cable；
Partial discharge detector, input terminal are connect with the detection impedance；
Display terminal is connect with the output terminal of the Partial discharge detector.
The shelf depreciation of cable under high direct voltage of the present invention and the combined detection system of leakage current use office
Portion discharges and two kinds of detection means of leakage current, wherein, shelf depreciation uses pulse current method and high-frequency current method (HFCT),
This is because：HFCT detects easy for installation, non-intrusion type, and working frequency is high, and nothing is directly electrically connected between cable and measuring loop,
Strong antijamming capability, sensitivity is higher, can obtain the transient state impulse waveform of high-frequency current.
In use, each element in the combined detection system described in the invention described above is sequentially connected, and ensure to be grounded good
It is good, next, high precision electro flow table to be carried out to correcting current zeroing respectively from high to low, set the threshold value of Partial discharge detector
Such as be set as 10pC and shelf depreciation correction is carried out to the combined detection system using High voltage output device, so that connection
Detecting system is closed in 0.5pc hereinafter, correction is completed.Then, the slowly voltage of raising High voltage output device, and keep the voltage etc.
Grade, high precision electro flow table choose suitable range, record present discharge voltage value, oscillograph recording present discharge impulse wave
Shape.High precision electro flow table uses continuous acquisition pattern, non-volatile recording leakage current and its fluctuation situation, and oscillograph is using segmentation
Drainage pattern records high-frequency current continuous discharge pulse.Then, ladder boost operations are carried out, record several different voltages
Discharge voltage numerical value and Discharge pulse waveform under grade.
Further, the joint-detection system of the shelf depreciation of cable and leakage current under high direct voltage of the present invention
In system, the High voltage output device includes：
High-tension transformer；
Alternating current-direct current divider is connected in parallel with the high-tension transformer；
Filter condenser is connected in parallel with the high-tension transformer；
Water resistance is protected, is connected with the high-tension transformer, alternating current-direct current divider and filter condenser being connected in parallel, it is described
The output terminal for protecting water resistance is the high-voltage output end of the High voltage output device.
Further, the joint-detection system of the shelf depreciation of cable and leakage current under high direct voltage of the present invention
In system, the high precision electro flow table includes pico-ampere table or Naan table.
In said program, it is preferred to use pico-ampere table or Naan table are because can be used for carrying out the long-time inspection of leakage current
It surveys and data stores, and measurement range is big, can measure the electric current of 20fA to 20mA, and high certainty of measurement.In some embodiment party
In formula, pico-ampere table signal input part uses BNC connecting lines of standard, and the signal wire part connecting cable of BNC connecting lines is connect
Head ground wire, by the shielded layer partial earthing of BNC connecting lines.
Correspondingly, another object of the present invention is to provide the shelf depreciation and leakage current of cable under a kind of high direct voltage
Associated detecting method, more effectively objectively cable under DC voltage can be detected using the associated detecting method.
Based on above-mentioned purpose, the invention also provides the shelf depreciation of cable and the connection of leakage current under a kind of high direct voltage
Detection method is closed, the shelf depreciation of cable and the combined detection system of leakage current under above-mentioned high direct voltage is used to be examined
It surveys, the associated detecting method includes step：
(1) Partial Discharge Data and leakage current data of the cable sample measured based on the combined detection system, it is right
The Partial Discharge Data and leakage current data of cable sample carry out feature extraction respectively, to construct the first evidence body and the second card
According to body；
(2) the first evidence somatic nerves network and the second evidence somatic nerves network are built, obtains the first evidence body, the second evidence
Body various Mode As corresponding to each cable sample respectivelyjThe accuracy S being identified1(Aj) and S2(Aj)；
(3) based on accuracy S1(Aj) and S2(Aj), the first evidence body, the second evidence body are obtained to various Mode AsjPower system
Number W1(Aj) and W2(Aj)；
(4) it using the Partial Discharge Data and leakage current data of combined detection system detection cable under test, and adopts
With the first evidence somatic nerves network and the second evidence somatic nerves network built in step (2) to the Partial Discharge Data and leakage
Current data is identified, and obtains the first evidence body, the second evidence body to various Mode AsjBasic probability assignment m1(Aj) and m2
(Aj)；
(5) based on W1(Aj) and W2(Aj) and m1(Aj) and m2(Aj) the first evidence body, the second evidence body are obtained to various moulds
Formula AjProbability-weighted distribution Wm1(Aj) and Wm2(Aj) and the weighting to all set of modes of the first evidence body, the second evidence body
Probability assignments Wm1(Θ) and Wm2(Θ)；
(6) by the first evidence body and the second evidence body weighted array, the probability-weighted distribution W after being synthesizedm(Aj)；
(7) W is distributed based on the probability-weighted after synthesism(Aj) judgement testing result：It is worth maximum Wm(Aj) corresponding pattern
AjRepresent the state of cable under test.
Identification process of the associated detecting method of the present invention based on D-S evidence theory includes：Characteristic parameter extraction, list
Evidence body weighting processing and more evidence body Weighted Fusions, that is to say, that Partial Discharge Data and let out by step (1) first
Leakage data carries out feature extraction respectively, to construct the first evidence body and the second evidence body；Later by step (2)~(5),
Document is carried out for the first evidence body and the second evidence body to handle according to the weighting of body, and by the way that adding for each evidence body is calculated
Weigh probability assignments；Multiple evidence bodies after the first evidence body and the synthesis of the second evidence body are carried out finally by step (6)~(7)
Weighted Fusion identifies, the result that is individually identified of multiple evidence bodies is weighted fusion, obtains final identification conclusion.
Based on this so that associated detecting method of the present invention detects two types due to the use of D-S evidence theory
Information carries out effective integration, builds the identification system of Weighted Fusion, so as to greatly improve detection and pattern-recognition sensitivity, overcomes
The situation of the insulation degradation of the prior art that can not be judged or judge by accident using single type data or defect.
Further, in associated detecting method of the present invention, step (1) includes：
(1a) constructs framework of identification：Construct normal mode and (n-1) kind defect mode System Discrimination frame for Θ=
{A1, A2, A3……An, in formula, A1Represent normal mode；A2~AnA variety of different defect modes are represented respectively；
(1b) constructs the first evidence body E1 and the second evidence body E2 of the System Discrimination frame Θ：Each corresponding mould
Formula makes the High voltage output device export k voltage class, obtains the corresponding Partial Discharge Data of each voltage class and lets out
Leakage data, the Partial Discharge Data and leakage current data include：The average office of Partial discharge detector's acquisition
Portion's discharge capacity and partial discharge repetition rate, the Partial Discharge of the oscillograph recording, the high-precision current token record
Leakage current mean value；Wherein for each pattern, the average partial discharge quantity q and the ratio of voltage U under each voltage class are used
The ratio t=f/U of value s=q/U, partial discharge repetition rate f and voltage U are as local discharge characteristic, using under each voltage class
Voltage U and leakage current mean value I ratio r=U/I as leakage current feature, extract local discharge characteristic vector E1=
[s1,s2...,sk,t1,t2...,tk] and leakage current feature vector E2=[r1,r2...,rk] respectively as the System Discrimination
The first evidence body E1 of frame Θ and the second evidence body E2.
Further, in associated detecting method of the present invention, the cable sample includes normal mode sample, gas
Gap defect mode sample, tip corona defect mode sample and scratch defects pattern sample, the various patterns include at least：Just
Norm formula, void defects pattern, tip corona defect mode and scratch defects pattern.
Further, in associated detecting method of the present invention, in step (2), a part of sample data is made
For training set sample data, using another part sample data as test set sample data, using training set sample data to two
A evidence somatic nerves network is trained respectively, and two evidence somatic nerves networks are carried out respectively using test set sample data
Test, obtains two evidence bodies accuracy S that various patterns corresponding to each cable sample are identified respectively1(Aj) and S2
(Aj)。
In addition, the application of associated detecting method of the present invention is described further：
Each evidence body is included into the first evidence body and pattern each in framework of identification is identified just in the second evidence body
True rate is Si(Aj) → [0,1],J=1,2,3,4 ... n, n represent pattern count included in System Discrimination frame
Amount.Definition mapping Wi() is the weight coefficient partition function on framework of identification Θ, wherein, i i-th of evidence body of expression, i=1,2,
The first evidence body is represented as i=1, the second evidence body is represented as i=2：
The mapping m defined in such as following formula (2):2 Θ → [0,1] is the Basic probability assignment function on framework of identification Θ.
mi(Aj) it is known as the i-th evidence body to AjBasic probability assignment, mi(Θ) is elementary probability point of i-th evidence to framework of identification Θ
Match：
The mapping Wm defined by such as following formula (3):2Θ→ [0,1] is the probability-weighted partition function on Θ.Wmi(Aj) be known as
I-th evidence body is to AjProbability-weighted distribution：
If P, Q are the subset of framework of identification Θ, for
Wherein, N is specification number in formula (4), its effect is that reliability lost in empty set is prorated to non-empty
On collection, to meet the requirement of probability assignments.
Recognition decision uses following formula (6) such as to judge, i.e. maximum Wm(Aj) pattern that as finally judges of corresponding pattern
Ac, i.e. Mode A c represent the state of cable under test：
The combined detection system of the shelf depreciation of cable and leakage current can overcome under high direct voltage of the present invention
The situation of the insulation degradation of the prior art that can not be judged or be judged by accident using single type data or defect, can effectively detect
Go out the shelf depreciation of cable and the situation of leakage current.
And associated detecting method of the present invention is used to carry out effective integration to two types detection information due to using,
The identification system of Weighted Fusion is built, so as to greatly improve detection and pattern-recognition sensitivity, and then effectively detects high direct voltage
The state of lower cable, provides more objective testing result.
Description of the drawings
Fig. 1 is the shelf depreciation of cable under high direct voltage of the present invention and the combined detection system of leakage current one
Structure diagram under kind embodiment.
Fig. 2 is the shelf depreciation of cable under high direct voltage of the present invention and the associated detecting method of leakage current one
Flow diagram under kind embodiment.
Fig. 3 illustrates the shelf depreciation of cable and the associated detecting method of leakage current under the high direct voltage that the present invention states and exists
A kind of application negative voltage discharge capacity under embodiment changes over time collection of illustrative plates.
Fig. 4 illustrates the shelf depreciation of cable and the associated detecting method of leakage current under the high direct voltage that the present invention states and exists
A kind of application positive voltage discharge capacity under embodiment changes over time collection of illustrative plates.
Fig. 5 illustrates the shelf depreciation of cable and the associated detecting method of leakage current under the high direct voltage that the present invention states and exists
Repetitive rate of discharging under a kind of application negative voltage under embodiment changes over time collection of illustrative plates.
Fig. 6 illustrates the shelf depreciation of cable and the associated detecting method of leakage current under the high direct voltage that the present invention states and exists
Repetitive rate of discharging under a kind of application positive voltage under embodiment changes over time collection of illustrative plates.
Fig. 7 illustrates the shelf depreciation of cable and the associated detecting method of leakage current under the high direct voltage that the present invention states and exists
Leakage current changes over time collection of illustrative plates under a kind of application negative voltage under embodiment.
Fig. 8 illustrates the shelf depreciation of cable and the associated detecting method of leakage current under the high direct voltage that the present invention states and exists
Leakage current changes over time collection of illustrative plates under a kind of application positive voltage under embodiment.
Specific embodiment
The part of cable under high direct voltage of the present invention will be put according to specific embodiment and Figure of description below
The combined detection system and associated detecting method of electricity and leakage current are described further, but the explanation is not formed to this hair
The improper restriction of bright technical solution.
Fig. 1 is the shelf depreciation of cable under high direct voltage of the present invention and the combined detection system of leakage current one
Structure diagram under kind embodiment.
As shown in Figure 1, in the present embodiment, combined detection system includes：High voltage output device, high precision electro flow table 3,
High Frequency Current Sensor 4, oscillograph 5, detection branch, Partial discharge detector 7 and display terminal 8.Wherein, High voltage output fills
Put including high-tension transformer 21, with alternating current-direct current divider 22 that high-tension transformer 21 is connected in parallel, in parallel with high-tension transformer connect
The filter condenser 23 connect and the protection water power connected with high-tension transformer 21, alternating current-direct current divider 22 and filter condenser 23
Resistance 24, and the output terminal of water resistance 24 is protected as the high-voltage output end of High voltage output device.Connect in addition, detection branch includes series connection
The detection capacitance 61 connect and detection impedance 62, and detect high-voltage output end and cable that tributary is connected to High voltage output device
Between the ground terminal of 1 ground wire.
In the present embodiment, High voltage output device is used to export high voltage direct current, the High voltage output of High voltage output device
End is connect with one end of cable 1.And high precision electro flow table 3 is serially connected on the ground wire of cable 1, high precision electro flow table 3 is used to examine
Survey leakage current；High Frequency Current Sensor 4, pincers are on the ground wire of cable 1；Oscillograph 5 connects with High Frequency Current Sensor 4
It connects, oscillograph 5 is used to acquire and store partial discharge pulse's signal of the transmission of High Frequency Current Sensor 4；Partial discharge detector 7
Input terminal with detection impedance 62 connect；Display terminal 8 is connect with the output terminal of Partial discharge detector 7.
It should be noted that in the present embodiment, high-tension transformer 21 is 5kVA/200kV (DC) high-tension transformer, is handed over
Divider 22 is using 200kV/100pF alternating current-direct current divider, and filter condenser 23 is using 200kV/10000pF
Filter condenser, protection water resistance protect water resistance for 10K Ω.
In addition, in the present embodiment, high precision electro flow table 3 is using pico-ampere table, and range is in 20fA to 20mA.And
Pico-ampere table in present embodiment can be used for carrying out the long-time detection of leakage current and data storage.The pico-ampere table signal is defeated
Enter end using BNC connecting lines of standard, the signal wire part connecting cable connector of BNC connecting lines is grounded, by BNC connecting lines
Shielded layer partial earthing.
In addition, instrument of the prior art may be used in high precision electro flow table 3, oscillograph 5 and Partial discharge detector 7
Device, such as：6485 types of KEITHLEY may be used in high precision electro flow table 3, and Lecroy 625Zi may be used in oscillograph 5, part
HAEFELY DDX9121b may be used in discharge detector 7.
During operation, by the shelf depreciation of cable under the high direct voltage in present embodiment and the joint-detection system of leakage current
System is attached, and ensure that system earth is good as shown in Figure 1, then divides the gear of High Frequency Current Sensor 3 from high to low
Calibration zeroing is not carried out；The threshold value of Partial discharge detector 7 is set as 10pC and is corrected, using High voltage output device to this implementation
Combined detection system in mode carries out shelf depreciation correction, so that combined detection system is completed in 0.5pc hereinafter, correcting.
Then, the slowly voltage of raising High voltage output device, and keep the voltage class, high precision electro flow table choose suitable range, note
The lower present discharge voltage value of record, oscillograph recording present discharge impulse waveform.High precision electro flow table uses continuous acquisition pattern,
Non-volatile recording leakage current and its fluctuation situation, oscillograph use piecewise acquisition pattern, record high-frequency current continuous discharge arteries and veins
Punching.Then, ladder boost operations are carried out, record the discharge voltage numerical value and discharge pulse under several different voltages grades
Waveform.
Fig. 2 is the shelf depreciation of cable under high direct voltage of the present invention and the associated detecting method of leakage current one
Flow diagram under kind embodiment.
It is examined using the shelf depreciation of cable under high direct voltage as shown in Figure 1 and the combined detection system of leakage current
It surveys, the flow of the associated detecting method in present embodiment is as shown in Figure 2.It is weighted by feature extraction, document according to body and more
The fusion of evidence body finally judges the situation of cable, and associated detecting method specific steps include：
(1) Partial Discharge Data and leakage current data of the cable sample measured based on the combined detection system, it is right
The Partial Discharge Data and leakage current data of cable sample carry out feature extraction respectively, to construct the first evidence body and the second card
According to body；
(2) the first evidence somatic nerves network and the second evidence somatic nerves network are built, obtains the first evidence body, the second evidence
Body various Mode As corresponding to each cable sample respectivelyjThe accuracy S being identified1(Aj) and S2(Aj), by a part of sample number
According to as training set sample data, using another part sample data as test set sample data, training set sample data is used
Two evidence somatic nerves networks are trained respectively, and using test set sample data respectively to two evidence somatic nerves networks
It is tested, obtains two evidence bodies accuracy S that various patterns corresponding to each cable sample are identified respectively1(Aj) and
S2(Aj)；
(3) based on accuracy S1(Aj) and S2(Aj), the first evidence body, the second evidence body are obtained to various Mode AsjPower system
Number W1(Aj) and W2(Aj)；
(4) it using the Partial Discharge Data and leakage current data of combined detection system detection cable under test, and adopts
With the first evidence somatic nerves network and the second evidence somatic nerves network built in step (2) to the Partial Discharge Data and leakage
Current data is identified, and obtains the first evidence body, the second evidence body to various Mode AsjBasic probability assignment m1(Aj) and m2
(Aj)；
(5) based on W1(Aj) and W2(Aj) and m1(Aj) and m2(Aj) the first evidence body, the second evidence body are obtained to various moulds
Formula AjProbability-weighted distribution Wm1(Aj) and Wm2(Aj) and the weighting to all set of modes of the first evidence body, the second evidence body
Probability assignments Wm1(Θ) and Wm2(Θ)；
(6) by the first evidence body and the second evidence body weighted array, the probability-weighted distribution W after being synthesizedm(Aj)；
(7) W is distributed based on the probability-weighted after synthesism(Aj) judgement testing result：It is worth maximum Wm(Aj) corresponding pattern
AjRepresent the state of cable under test.
It should be noted that in the present embodiment, the cable sample includes normal mode sample, void defects pattern
Sample, tip corona defect mode sample and scratch defects pattern sample.
In some other embodiments, the various patterns include at least：Normal mode, void defects pattern, point
Hold corona defect mode and scratch defects pattern.
In addition, in the present embodiment, step (1) includes：
(1a) constructs framework of identification：Construct normal mode and (n-1) kind defect mode System Discrimination frame for Θ=
{A1, A2, A3……An, in formula, A1Represent normal mode；A2~AnA variety of different defect modes are represented respectively, due to this reality
Cable sample in mode is applied to include：Normal mode, void defects pattern, tip corona defect mode and scratch defects pattern,
That is n=4；AjIt represents certain corresponding cable mode, works as j=1, i.e. A1Normal mode is represented, as j=2, that is, A2Represent gas
Gap defect mode, as j=3, that is, A3Tip corona defect mode is represented, as j=4, that is, A4Represent scratch defects pattern；
(1b) constructs the first evidence body E1 and the second evidence body E2 of the System Discrimination frame Θ：Each corresponding mould
Formula makes High voltage output device export k voltage class (in the present embodiment, take 5 voltage class, thus, k=5), acquisition
The corresponding Partial Discharge Data of each voltage class and leakage current data, Partial Discharge Data and leakage current data packet
It includes：The average partial discharge quantity and partial discharge repetition rate that Partial discharge detector 7 acquires, the shelf depreciation that oscillograph 5 records
Waveform, the leakage current mean value that high precision electro flow table 3 records；Wherein for each pattern, using flat under each voltage class
Ratio s=q/U, the partial discharge repetition rate f of equal partial discharge quantity q and voltage U are put with the ratio t=f/U of voltage U as part
Electrical feature, using the voltage U under each voltage class and leakage current mean value I ratio r=U/I as leakage current feature, carry
Take local discharge characteristic vector E1=[s1,s2...,sk,t1,t2...,tk] and leakage current feature vector E2=[r1,r2...,
rk] respectively as the first evidence body E1 and the second evidence body E2 of the System Discrimination frame Θ.
Each card is obtained according to step (2) for 60 groups of data of cable sample under different conditions pattern in the present embodiment
According to body to various Mode AsjAccuracy, based on accuracy S1(Aj) and S2(Aj) by step (3), obtain the first evidence body,
Two evidence bodies are to various Mode AsjWeight coefficient W1(Aj) and W2(Aj), result such as Tables 1 and 2.
The accuracy of 1. each evidence body of table
The weight coefficient of 2. each evidence body of table
In order to further illustrate the credible result degree for using the associated detecting method in present embodiment, for being in air gap
Defect mode (i.e. A2Pattern) cable sample data illustrate.
The data acquired by combined detection system shown in FIG. 1, the data result of acquisition as shown in Figures 3 to 8, are schemed
I, II, III, IV, V in 3 to Fig. 8 represent different voltage class respectively, voltage value be respectively -4.6kV, -8.9kV, -
13.1kV, -17.5kV and -22.6kV, and VI, VII, VIII, IX, X represent different voltage class, voltage value point respectively
It Wei not+4.3kV ,+8.9kV ,+13.2kV ,+19kV and+23kV.
Fig. 3 illustrates the shelf depreciation of cable and the associated detecting method of leakage current under the high direct voltage that the present invention states and exists
A kind of application negative voltage discharge capacity under embodiment changes over time collection of illustrative plates.Fig. 4 illustrates the high direct voltage that the present invention states
A kind of application positive voltage discharge capacity of the shelf depreciation of lower cable and the associated detecting method of leakage current under embodiment
Change over time collection of illustrative plates.Fig. 5 illustrates the shelf depreciation of cable and the inspection of the joint of leakage current under the high direct voltage that the present invention states
Repetitive rate of discharging under a kind of application negative voltage of the survey method under embodiment changes over time collection of illustrative plates.Fig. 6 illustrates the present invention
A kind of application of the shelf depreciation of cable and the associated detecting method of leakage current under embodiment is being just under the high direct voltage stated
Repetitive rate of discharging under voltage changes over time collection of illustrative plates.Fig. 7 illustrate under the high direct voltage stated of the present invention shelf depreciation of cable and
Leakage current changes over time collection of illustrative plates under a kind of application negative voltage of the associated detecting method of leakage current under embodiment.Figure
8 illustrate under the high direct voltage stated of the present invention shelf depreciation of cable and the associated detecting method of leakage current in a kind of embodiment party
Leakage current changes over time collection of illustrative plates under application positive voltage under formula.
Table 3 lists the Comparative result of the weighted evidence fusion recognition of the sample data under each pattern.
Table 3.
By analyzing table 3 it is found that being identified respectively using shelf depreciation and leakage current data, judgement result is A2
Probability be respectively 52% and 59%.Recognition correct rate has been increased to 90% after each evidence is handled by weighting.It is it can be seen that more
Evidence body Weighted Fusion can significantly improve Classification and Identification ability of the identifying system to state model, that is to say, that using this hair
The bright combined detection system and method greatly improve detection and pattern-recognition sensitivity, can provide more objective detection
As a result.
It should be noted that prior art part is not limited to given by present specification in protection scope of the present invention
Embodiment, all prior arts not contradicted with the solution of the present invention, including but not limited to first patent document, formerly
Public publication, formerly openly use etc., it can all be included in protection scope of the present invention.
In addition, it should also be noted that, institute in the combination of each technical characteristic and unlimited this case claim in this case
Combination recorded in the combination or specific embodiment of record, all technical characteristics recorded in this case can be to appoint
Where formula is freely combined or is combined, unless generating contradiction between each other.
It should be noted that embodiment enumerated above is only specific embodiments of the present invention.Obviously not office of the invention
It is limited to above example, the similar variation or deformation made therewith are that those skilled in the art can be straight from present disclosure
It connects and obtains or be easy to what is just associated, be within the scope of protection of the invention.
Claims (7)
1. a kind of combined detection system of the shelf depreciation of cable and leakage current under high direct voltage, which is characterized in that including：
High voltage output device is used to export high voltage direct current, the high-voltage output end of the High voltage output device and the one of cable
End connection；
High precision electro flow table is serially connected on the ground wire of the cable, and the high precision electro flow table is used to detect leakage current；
High Frequency Current Sensor, pincers are on the ground wire of the cable；
Oscillograph is connect with the High Frequency Current Sensor, and the part of acquisition and storage High Frequency Current Sensor transmission is put
Electric impulse signal；
Detection branch, including the detection capacitance being connected in series with and detection impedance, it is defeated that the detection branch is connected to the high pressure
Go out between the ground terminal of the high-voltage output end of device and the ground wire of cable；
Partial discharge detector, input terminal are connect with the detection impedance；
Display terminal is connect with the output terminal of the Partial discharge detector.
2. the combined detection system of the shelf depreciation of cable and leakage current under high direct voltage as described in claim 1, special
Sign is that the High voltage output device includes：
High-tension transformer；
Alternating current-direct current divider is connected in parallel with the high-tension transformer；
Filter condenser is connected in parallel with the high-tension transformer；
Water resistance is protected, is connected with the high-tension transformer, alternating current-direct current divider and filter condenser being connected in parallel, the protection
The output terminal of water resistance is the high-voltage output end of the High voltage output device.
3. the combined detection system of the shelf depreciation of cable and leakage current under high direct voltage as described in claim 1, special
Sign is that the high precision electro flow table includes pico-ampere table or Naan table.
4. the associated detecting method of the shelf depreciation of cable and leakage current under a kind of high direct voltage, uses such as claim 1-
The shelf depreciation of cable and the combined detection system of leakage current are detected under high direct voltage in 3 described in any one,
It is characterized in that, the associated detecting method includes step：
(1) Partial Discharge Data and leakage current data of the cable sample measured based on the combined detection system, to cable
The Partial Discharge Data and leakage current data of sample carry out feature extraction respectively, to construct the first evidence body and the second evidence
Body；
(2) the first evidence somatic nerves network and the second evidence somatic nerves network are built, obtains the first evidence body, the second evidence body point
Other various Mode As corresponding to each cable samplejThe accuracy S being identified1(Aj) and S2(Aj)；
(3) based on accuracy S1(Aj) and S2(Aj), the first evidence body, the second evidence body are obtained to various Mode AsjWeight coefficient W1
(Aj) and W2(Aj)；
(4) using the Partial Discharge Data and leakage current data of combined detection system detection cable under test, and using step
Suddenly the first evidence somatic nerves network and the second evidence somatic nerves network built in (2) is to the Partial Discharge Data and leakage current
Data are identified, and obtain the first evidence body, the second evidence body to various Mode AsjBasic probability assignment m1(Aj) and m2(Aj)；
(5) based on W1(Aj) and W2(Aj) and m1(Aj) and m2(Aj) the first evidence body, the second evidence body are obtained to various Mode Asj
Probability-weighted distribution Wm1(Aj) and Wm2(Aj) and the first evidence body, the second evidence body to the probability-weighteds of all set of modes
Distribute Wm1(Θ) and Wm2(Θ)；
(6) by the first evidence body and the second evidence body weighted array, the probability-weighted distribution W after being synthesizedm(Aj)；
(7) W is distributed based on the probability-weighted after synthesism(Aj) judgement testing result：It is worth maximum Wm(Aj) corresponding Mode AjI.e.
Represent the state of cable under test.
5. associated detecting method as claimed in claim 4, which is characterized in that step (1) includes：
(1a) constructs framework of identification：The System Discrimination frame for constructing normal mode and (n-1) kind defect mode is Θ={ A1, A2,
A3……Aj, An, in formula, A1Represent normal mode；A2~AnA variety of different defect modes are represented respectively；
(1b) constructs the first evidence body E1 and the second evidence body E2 of the System Discrimination frame Θ：Each corresponding pattern, makes
The High voltage output device exports k voltage class, obtains the corresponding Partial Discharge Data of each voltage class and leakage electricity
Flow data, the Partial Discharge Data and leakage current data include：It puts the average part of Partial discharge detector's acquisition
Electricity and partial discharge repetition rate, the Partial Discharge of the oscillograph recording, the leakage of the high-precision current token record
Electric current mean value；Wherein for each pattern, the ratio s=of the average partial discharge quantity q under each voltage class and voltage U is used
The ratio t=f/U of q/U, partial discharge repetition rate f and voltage U use the voltage under each voltage class as local discharge characteristic
Ratio r=U/I of U and leakage current mean value I is as leakage current feature, extraction local discharge characteristic vector E1=[s1,
s2...,sk,t1,t2...,tk] and leakage current feature vector E2=[r1,r2...,rk] respectively as the System Discrimination frame
The first evidence body E1 of Θ and the second evidence body E2.
6. associated detecting method as claimed in claim 4, which is characterized in that the cable sample include normal mode sample,
Void defects pattern sample, tip corona defect mode sample and scratch defects pattern sample, the various patterns include at least：
Normal mode, void defects pattern, tip corona defect mode and scratch defects pattern.
7. associated detecting method as claimed in claim 4, which is characterized in that in step (2), a part of sample data is made
For training set sample data, using another part sample data as test set sample data, using training set sample data to two
A evidence somatic nerves network is trained respectively, and two evidence somatic nerves networks are carried out respectively using test set sample data
Test, obtains two evidence bodies accuracy S that various patterns corresponding to each cable sample are identified respectively1(Aj) and S2
(Aj)。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711418638.7A CN108254659A (en) | 2017-12-25 | 2017-12-25 | The shelf depreciation of cable and the combined detection system of leakage current and method under high direct voltage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711418638.7A CN108254659A (en) | 2017-12-25 | 2017-12-25 | The shelf depreciation of cable and the combined detection system of leakage current and method under high direct voltage |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108254659A true CN108254659A (en) | 2018-07-06 |
Family
ID=62723773
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711418638.7A Pending CN108254659A (en) | 2017-12-25 | 2017-12-25 | The shelf depreciation of cable and the combined detection system of leakage current and method under high direct voltage |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108254659A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109283444A (en) * | 2018-11-26 | 2019-01-29 | 国网安徽省电力有限公司淮南供电公司 | Double principle cable local discharge sensors and its data fusion method |
| CN110389283A (en) * | 2019-08-09 | 2019-10-29 | 国网电力科学研究院武汉南瑞有限责任公司 | A kind of cable slack layer ablation condition detecting system and detection method |
| CN110531209A (en) * | 2019-09-23 | 2019-12-03 | 南方电网科学研究院有限责任公司 | A kind of arrester resistor-piece side glaze leakage current test macro |
| WO2020186718A1 (en) * | 2019-03-20 | 2020-09-24 | 国网电力科学研究院武汉南瑞有限责任公司 | Method and system for determining insulation state of direct current cable, and storage medium |
| CN111880111A (en) * | 2020-06-23 | 2020-11-03 | 南方电网科学研究院有限责任公司 | Leakage current measuring device, system and method for high-voltage direct current cable |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101464235A (en) * | 2009-01-12 | 2009-06-24 | 重庆大学 | Test method and apparatus for polymer power cable insulation accelerated electric tree aging |
| CN201522543U (en) * | 2009-11-02 | 2010-07-07 | 华北电力大学 | Transformer winding turn-to-turn partial discharge joint detection and diagnostic platform |
| CN203025309U (en) * | 2012-12-20 | 2013-06-26 | 四川电力科学研究院 | Direct current partial discharge test analysis device for analog converter transformer |
| CN103364699A (en) * | 2013-07-19 | 2013-10-23 | 华北电力大学 | Cable discharging fault detection device |
| CN104714155A (en) * | 2015-02-02 | 2015-06-17 | 西安交通大学 | Detection and evaluation device and method for partial discharge of direct current XLPE cables |
| CN105629139A (en) * | 2015-12-29 | 2016-06-01 | 武汉大学 | Gas insulated electrical equipment partial discharge multi-source combined monitoring experiment device |
| CN106707128A (en) * | 2017-03-16 | 2017-05-24 | 国家电网公司 | Acoustoelectric associated local cable discharge locating device and method |
| US20170256925A1 (en) * | 2014-10-16 | 2017-09-07 | Repl International Limited | Medium-voltage cable joint |
| CN206671472U (en) * | 2017-04-11 | 2017-11-24 | 国网新疆电力公司电力科学研究院 | High-tension cable local discharge detection device |
-
2017
- 2017-12-25 CN CN201711418638.7A patent/CN108254659A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101464235A (en) * | 2009-01-12 | 2009-06-24 | 重庆大学 | Test method and apparatus for polymer power cable insulation accelerated electric tree aging |
| CN201522543U (en) * | 2009-11-02 | 2010-07-07 | 华北电力大学 | Transformer winding turn-to-turn partial discharge joint detection and diagnostic platform |
| CN203025309U (en) * | 2012-12-20 | 2013-06-26 | 四川电力科学研究院 | Direct current partial discharge test analysis device for analog converter transformer |
| CN103364699A (en) * | 2013-07-19 | 2013-10-23 | 华北电力大学 | Cable discharging fault detection device |
| US20170256925A1 (en) * | 2014-10-16 | 2017-09-07 | Repl International Limited | Medium-voltage cable joint |
| CN104714155A (en) * | 2015-02-02 | 2015-06-17 | 西安交通大学 | Detection and evaluation device and method for partial discharge of direct current XLPE cables |
| CN105629139A (en) * | 2015-12-29 | 2016-06-01 | 武汉大学 | Gas insulated electrical equipment partial discharge multi-source combined monitoring experiment device |
| CN106707128A (en) * | 2017-03-16 | 2017-05-24 | 国家电网公司 | Acoustoelectric associated local cable discharge locating device and method |
| CN206671472U (en) * | 2017-04-11 | 2017-11-24 | 国网新疆电力公司电力科学研究院 | High-tension cable local discharge detection device |
Non-Patent Citations (1)
| Title |
|---|
| 唐炬 等: "气体绝缘电器局部放电模式的多特征信息融合决策诊断", 《高电压技术》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109283444A (en) * | 2018-11-26 | 2019-01-29 | 国网安徽省电力有限公司淮南供电公司 | Double principle cable local discharge sensors and its data fusion method |
| CN109283444B (en) * | 2018-11-26 | 2021-01-05 | 国网安徽省电力有限公司淮南供电公司 | Dual-principle cable partial discharge sensor and data fusion method thereof |
| WO2020186718A1 (en) * | 2019-03-20 | 2020-09-24 | 国网电力科学研究院武汉南瑞有限责任公司 | Method and system for determining insulation state of direct current cable, and storage medium |
| CN110389283A (en) * | 2019-08-09 | 2019-10-29 | 国网电力科学研究院武汉南瑞有限责任公司 | A kind of cable slack layer ablation condition detecting system and detection method |
| CN110531209A (en) * | 2019-09-23 | 2019-12-03 | 南方电网科学研究院有限责任公司 | A kind of arrester resistor-piece side glaze leakage current test macro |
| CN111880111A (en) * | 2020-06-23 | 2020-11-03 | 南方电网科学研究院有限责任公司 | Leakage current measuring device, system and method for high-voltage direct current cable |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108254659A (en) | The shelf depreciation of cable and the combined detection system of leakage current and method under high direct voltage | |
| CN107607837B (en) | Cable insulation aging degree testing method and device based on impulse voltage | |
| CN104714155B (en) | A kind of detection to direct current XLPE cable shelf depreciation and apparatus for evaluating and method | |
| CN104155626B (en) | The system that ground potential climbing capacity resisted by a kind of detection voltage transformer | |
| CN109814005A (en) | A kind of cable insulation defect recognition and localization method and system | |
| CN110275096A (en) | Insulator surface defect local discharge detection device and detection method | |
| Xu et al. | Special requirements of high frequency current transformers in the on-line detection of partial discharges in power cables | |
| CN108008254A (en) | A kind of Failure Diagnosis of Substation Ground Network method and device | |
| CN203191508U (en) | GIS partial-discharge detection test platform based on transient-earthing radio waves | |
| Peng et al. | SDMF based interference rejection and PD interpretation for simulated defects in HV cable diagnostics | |
| Takahashi et al. | AC and DC partial discharge measurements on defective cables | |
| CN108761184B (en) | Iron tower potential distribution and impedance characteristic testing method based on lightning impulse | |
| US10948532B1 (en) | Insulation diagnosis and positioning method for insulated bus pipe | |
| Bergius | Implementation of on-line partial discharge measurements in medium voltage cable network | |
| US6825670B2 (en) | Method and device for testing a telecommunication cable | |
| Neumann et al. | PD measurements on a DC gas-insulated transmission line (DC GIL) conducted in the frame of the Prototype Installation Test according to recommendation of CIGRE JWG D1/B3. 57 | |
| Oyegoke et al. | Condition assessment of XLPE cable insulation using short-time polarisation and depolarisation current measurements | |
| CN108344928A (en) | A kind of power cable local discharge on-line monitoring device and method | |
| CN107643440B (en) | Detection device for human body power frequency induced current and application method thereof | |
| Chang et al. | The detection of change-point of partial discharges on power cable joints | |
| CN106610480A (en) | Multi-parameter ultra-high frequency sensor performance comprehensive evaluation method | |
| Gite et al. | Interpretation of sweep frequency response data (SFRA) using graphical and statistical technique | |
| Shafiq et al. | Propagation characteristics of partial discharge signals in medium voltage branched cable joints using HFCT sensor | |
| Setyowibowo et al. | Partial discharge measurements in XLPE cables with misplaced grading system under different applied voltage frequencies | |
| Hu et al. | Practical aspects of partial discharge measurement for HVDC cables |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20180706 |
|
| WD01 | Invention patent application deemed withdrawn after publication |