CN106501690A - A kind of XLPE power cables partial discharge diagnostic method and system - Google Patents

A kind of XLPE power cables partial discharge diagnostic method and system Download PDF

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Publication number
CN106501690A
CN106501690A CN201610961336.3A CN201610961336A CN106501690A CN 106501690 A CN106501690 A CN 106501690A CN 201610961336 A CN201610961336 A CN 201610961336A CN 106501690 A CN106501690 A CN 106501690A
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China
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signal
phase
ultrasonic
discharge
frequency
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CN201610961336.3A
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CN106501690B (en
Inventor
焦明航
欧阳群
焦明程
刘树泽
张琳
高阳
宋丽
张诗洋
黎斌
贾煜晗
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国网辽宁省电力有限公司辽阳供电公司
国家电网公司
沈阳工程学院
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/12Testing 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
    • G01R31/1209Testing 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 using acoustic measurements
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/12Testing 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
    • G01R31/1227Testing 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
    • G01R31/1263Testing 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
    • G01R31/1272Testing 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

Abstract

The invention belongs to electrical equipment fault detection and diagnostic techniquess field, are particularly a kind of XLPE power cables partial discharge diagnostic method and system, the method includes:The ultrasonic signal of the low frequency that collection power cable shelf depreciation is produced and ultrahigh frequency partial discharge signal, obtain the time delay of ultrasonic signal, obtain the distance of shelf depreciation point and Partial Discharge Detection point;Determine there is the phase window of shelf depreciation;Phase place opening relationships by the ultrasonic signal amplitude of phase window and the power-frequency voltage for being applied;The phase information of ultrasonic shelf depreciation and amplitude information are depicted as phase place spectrogram;Statistical nature calculating is carried out, 27 Statistical Operators for characterizing Characteristics of Partial Discharge are extracted.The ultrahigh frequency partial discharge signal that invention is produced with shelf depreciation is as time reference, and combines with the ultrasonic local discharge signal of low frequency, obtains the time delay of ultrasonic signal, finally realizes the identification of local discharge signal.

Description

A kind of XLPE power cables partial discharge diagnostic method and system
Technical field
The invention belongs to electrical equipment fault detection and diagnostic techniquess field, are particularly a kind of XLPE power cables Partial discharge diagnostic method and system.
Background technology
Cross-inked polyethylene power cable (Cross Linked Polyethylene, XLPE) is applied due to its light weight, installation If easily and being widely used in urban distribution network have the advantages that good electric and heat resistance.However, in actual motion XLPE power cables due to by mounting process, laying the factors such as environment, external force destruction, service condition and affected, cause insulation to lack Fall into, or even dielectric breakdown accident constantly occurs, wherein with intermediate joint of electric cable and the ratio of terminals adnexa insulation fault For many.
At present, domestic is an important means for ensureing XLPE power cable reliability services using preventive trial.However, The shortcomings of there is state of insulation when test period length, power failure result of the test can not accurately reflect operation in preventive trial;Additionally, It is a process for progressively developing that power cable insulation declines, and occurs in failure early stage, due to the office of power cable insulation system The discharge signal that portion's defect causes is very faint, and traditional preventive trial project is difficult to detect abnormal shelf depreciation letter Number, on the other hand, the outstanding problem that power cable scene Partial Discharge Detection faces is interference, if interference letter cannot be rejected Number, then power cable scene Partial Discharge Detection cannot be carried out substantially, and therefore, single conventional test methods cannot meet The requirement of urban power distribution network safe operation.
Shelf depreciation (Partial Discharge, PD) is the main forms of power cable insulation failure early stage, it It is both the one of the main reasons for causing insulation degradation, is the principal character amount for characterizing insulation status again.Operating experience and research are Show:Power cable partial discharge quantity is insulated from that state is closely related, and the change of partial discharge quantity imply that power cable Insulation system has some insulation defects to a certain extent, is one of effective ways of quantitative analyses insulation degradation degree. Therefore, the international electric power standard such as IEC, IEEE and CIGRE is consistent with mechanism of association recommends partial discharge test as XLPE electricity The best approach of power cable insulation status evaluation.
When power cable occurs shelf depreciation, pulse current, electromagnetic wave, sound, light, heat and chemistry can be supervened and become Change etc. physical phenomenon, the Partial Discharge Detection and diagnostic method for thus developing have pulse current method, superfrequency method, ultrasonic method, Light detection method and chemical measure etc..Ultrasonic method is that live interference signal is difficult to suppress, and superfrequency method using a sensor is Cannot play a game and put source positioning.
Content of the invention
The technical problem to be solved is to provide a kind of XLPE power cables partial discharge diagnostic method, realizes The identification of local discharge signal, the rejecting of interference signal, the positioning of insulation defect and diagnosis.
The present invention is achieved in that
A kind of XLPE power cables partial discharge diagnostic method, the method include:
Step 1, gathers ultrasonic signal and the ultrahigh frequency partial discharge signal of the low frequency that power cable shelf depreciation is produced, With ultrahigh frequency partial discharge signal as time reference, the time difference with the ultrasonic signal of low frequency is calculated, obtain ultrasonic signal Time delay, the spread speed that the time difference of delay is multiplied by ultrasonic local discharge signal, obtain shelf depreciation point with local The distance of discharge examination point;
Ultrasonic signal is carried out a point phase window by step 2, by the maximum amplitude absolute value of ultrasonic signal in phase window Compare with the discharge threshold for setting, determine there is the phase window of shelf depreciation;
Step 3, ultrasonic signal is carried out after waveform Adjustable calculation, by the ultrasonic signal amplitude of phase window with applied Power-frequency voltage phase place opening relationships;
The phase information of ultrasonic shelf depreciation and amplitude information are depicted as electric discharge amplitude phase spectrogram, maximum and are put by step 4 Electric amplitude phase spectrogram, averaged discharge amplitude phase spectrogram and discharge time phase place spectrogram;
The spectrogram of four kinds of ultrasonic local discharge signals in step 4 is carried out statistical nature calculating, extracts and characterize by step 5 27 Statistical Operators of Characteristics of Partial Discharge.
Further, step 2 includes:The power-frequency voltage signal that power cable applying is measured using potentiometer, one is adopted In 1 power frequency period of collection, power-frequency voltage signal is each separated into N number of phase window with the data of ultrasonic signal, and each phase window is M ultrasonic signal and M power-frequency voltage signal, a phase place of each phase window corresponding to power-frequency voltage, to per 1 phase place M ultrasonic signal in window seeks maximum amplitude, and the absolute value of maximum amplitude is compared with the discharge threshold for setting, this phase is determined Whether there is shelf depreciation in the window of position, record the maximum amplitude of the ultrasonic signal, and using the maximum amplitude as the phase window Ultrasonic signal amplitude.
Further, ultrasonic signal is carried out waveform Adjustable calculation by step 3 includes, to per M work in 1 phase window Frequency voltage signal is averaged, by the phase place opening relationships of the ultrasonic signal amplitude of phase window and the power-frequency voltage for being applied, 1~M phase window correspond to 0°~360°Phase place, make the corresponding sinusoidal wave form i* of ultrasonic signal amplitude of i-th phase window 360°The phase place of/M.
Further, by the ultrasonic signal amplitude of phase window and the phase place opening relationships bag of the power-frequency voltage for being applied Include:The voltage signal of rising edge zero crossing in 1 complete power frequency period is taken out, by voltage signal rising edge zero crossing window position Ultrasonic signal after putting toward reach, by the ultrasonic signal before voltage signal rising edge zero crossing the window's position backward Move, obtain the relation of the ultrasonic signal amplitude of phase window and the phase place of institute's applied voltage.
Further, feature includes:Mean μ, standard deviation sigma, degree of bias Sk, kurtosis KuAnd cross-correlation coefficient cc.
Further, the parameter for adopting for:Sample rate is 20MS/s, and acquisition time is 1 power frequency period, and sampling length is 400000 points, i.e. capture card are often gathered 1 time, just obtain 400000 data in 1 complete power frequency period time.
A kind of XLPE power cables partial discharge diagnosis system, the system include:
Sonac and superfrequency integrated sensor are respectively used to the low frequency that collection power cable shelf depreciation is produced Ultrasonic signal and ultrahigh frequency partial discharge signal;
Signal amplifies and conditioning unit, is amplified conditioning to ultrasonic signal and ultrahigh frequency partial discharge signal;
Capture card, by two channel reception ultrasonic signals and ultrahigh-frequency signal, realizes the real-time of local discharge signal Collection;
Data processing module, to gathering ultrasonic signal and the superfrequency local of the low frequency that power cable shelf depreciation is produced Discharge signal, with ultrahigh frequency partial discharge signal as time reference, calculates the time difference with the ultrasonic signal of low frequency, obtains The time delay of ultrasonic signal, the spread speed that the time difference of delay is multiplied by ultrasonic local discharge signal, obtains shelf depreciation Put the distance with Partial Discharge Detection point;
Ultrasonic signal is carried out a point phase window, by maximum amplitude absolute value and the setting of ultrasonic signal in phase window Discharge threshold compare, determine there is the phase window of shelf depreciation;
Ultrasonic signal is carried out after waveform Adjustable calculation, by the ultrasonic signal amplitude of phase window and the power frequency for being applied The phase place opening relationships of voltage;
The phase information of ultrasonic shelf depreciation and amplitude information are depicted as amplitude phase spectrum of discharging by spectrogram drafting module Figure, maximum electric discharge amplitude phase spectrogram, averaged discharge amplitude phase spectrogram and discharge time phase place spectrogram;
The spectrogram of four kinds of ultrasonic local discharge signals is carried out statistical nature calculating, is carried by discharge characteristic parametric statisticss module Take 27 Statistical Operators for characterizing Characteristics of Partial Discharge;
Display module, shows the spectrogram of four kinds of ultrasonic local discharge signals.
Further, signal amplification and conditioning unit include preamplifier, the band logical being sequentially connected with sonac Wave filter and buffer circuit, and low-noise amplifier, high pass filter and the cymoscope being sequentially connected with extra-high video sensor; Wherein, the output of preamplifier is connected with the input of band filter, band filter will with shelf depreciation ultrasonic signal without The various environment noises of pass, mechanical vibration noise etc. are filtered, and the output of band filter connects the input of buffer circuit, increase output Electric current.
Further, the output of extra-high video sensor connects the input of low noise amplifier and is followed by the input of high pass filter, High pass filter filters the low-frequency interference signal unrelated with partial-discharge ultrahigh-frequency signal, and the output of high pass filter connects detection The input of device, cymoscope move to low-frequency range super high band local discharge signal.
Further, capture card sample rate is 20MS/s, and acquisition time is 1 power frequency period, and sampling length is 400000 Individual, i.e., capture card is often gathered 1 time, just obtains 400000 data in 1 complete power frequency period time.
Compared with prior art, beneficial effect is the present invention:The present invention is put with the superfrequency local that shelf depreciation is produced The signal of telecommunication is time reference, and combines with the ultrasonic local discharge signal of low frequency, obtains the time delay of ultrasonic signal, finally The method for realizing the identification of local discharge signal, the rejecting of interference signal, the positioning of insulation defect and diagnosis.Compared to other inspections Survey method, ultrasonic method and superfrequency method integrated detection system are non-intrusion type, more satisfactory in-situ check and test method, by outside Electromagnetic noise impact is less, and is easily achieved live detection.Therefore, it is possible to judge the insulation shape of power cable in time and exactly State, finds some early stage latency defects, it is to avoid the generation of power cable breakdown accident early.
Description of the drawings
Fig. 1 is the system module block diagram of the present invention;
Circuit diagrams of the Fig. 2 for preamplifier;
Fig. 3 is the PRPD spectrograms of ultrasonic local discharge signal;
Fig. 4 is ultrasonic local discharge signalSpectrogram, (a) be 0~180 ° of phase place, (b) for 180 ° of phase place~ 360°;
Fig. 5 is ultrasonic local discharge signalSpectrogram, (a) be 0~180 ° of phase place, (b) for 180 ° of phase place~ 360°;
Fig. 6 is ultrasonic local discharge signalSpectrogram, (a) be 0~180 ° of phase place, (b) for 180 ° of phase place~ 360°.
Specific embodiment
In order that the objects, technical solutions and advantages of the present invention become more apparent, with reference to embodiments, to the present invention It is further elaborated.It should be appreciated that specific embodiment described herein is not used to only in order to explain the present invention Limit the present invention.
Referring to Fig. 1, the system of the present invention is amplified by sonac and extra-high video sensor (300MHz-3GHz), signal Constitute with conditioning unit, capture card, software analysis system and display device.Wherein, signal amplifies and conditioning unit includes ultrasound The signal of sensor amplifies and conditioning unit, and the signal of extra-high video sensor amplifies and conditioning unit, wherein, sonac Signal amplifies and conditioning unit includes preamplifier, three part of band filter and buffer circuit, the letter of extra-high video sensor Number amplify and conditioning unit include low-noise amplifier, three part of high pass filter and cymoscope;Software analysis system is by data Acquisition control module, data processing module, four module compositions of spectrogram drafting module and discharge characteristic parametric statisticss module;In figure Sonac adopts resonant mode high sensitivity ultrasonic sensor;Extra-high video sensor adopts electric capacity disk-type acyclic antenna; Preamplifier is made up of low noise operational amplifier;Band filter is made up of low distortion, high speed dual operational amplifier;Buffering Amplifier is made up of a buffer amplifier;Low noise amplifier is made up of the audion of low noise;Cymoscope is examined with diode Wave circuit is constituted;Capture card is selected and grinds magnificent PCI-9810;Software analysis system is developed jointly using LabVIEW language and C language Form.
During Site Detection, sonac, extra-high video sensor are affixed on detected XLPE power cables, when electric power electricity The insulation system existing defects of cable or hidden danger, and there is partial discharge phenomenon, now, sonac under normal working voltage Discharged the ultrasonic and ultrahigh-frequency signal for producing with portion of extra-high video sensor office of acceptance.
Sonac output connects the input of preamplifier.Sonac output signal is fainter, and maximum amplitude is only For 5mV or so, site environment noise and disturb larger, shelf depreciation ultrasonic signal can be caused to be submerged in noise;Additionally, super The output impedance of sonic transducer is high impedance, and therefore, preamplifier is mainly by input stage amplifier section D1, bandpass filtering part D2 and buffer amplifier D3 is constituted, and fixed gain is 40dB, and its structural representation is as shown in Fig. 2 another aspect, preposition amplification Integrated amplifier used in device possesses low noise and high input impedance.The Main Function of preamplifier is:1. amplify ultrasound The ultra-weak electronic signal of sensor output;2. the high output impedance of sonac is transformed to low output impedance.
The output of preamplifier is connected with the input of band filter.Band filter mainly will be with shelf depreciation ultrasound The unrelated various environment noises of signal, mechanical vibration noise etc. are filtered.
The output of band filter connects the input of buffer circuit.Purpose is to increase output current, improves load capacity, subtracts Load the impact to signal source less, increase capacity of resisting disturbance.
The output of extra-high video sensor connects the input of low noise amplifier.Extra-high video sensor output signal is very faint, Belong to V magnitudes, site environment noise and interference are larger, and partial-discharge ultrahigh-frequency signal can be caused to be submerged in noise.
The output of low noise amplifier connects the input of high pass filter.The effect of high pass filter is mainly handle and is put with local The unrelated low-frequency interference signal of electric ultrahigh-frequency signal is filtered.
The output of high pass filter connects the input of cymoscope.Cymoscope is mainly super high band local discharge signal (300MHz-3GHz) move to low-frequency range (DC-10MHz), the sample rate of such data acquisition unit avoid the need for too high, for example, The capture card of 100MS/s sample rates just can meet requirement.
The shelf depreciation ultrasonic signal and ultrahigh-frequency signal amplified with conditioning unit through signal is respectively connected to 2 of capture card Passage, realizes the Real-time Collection of local discharge signal.
By the data acquisition module control data capture card of local discharge signal software analysis system, which is carried out initially Change and arrange, gather signal, and place the data into queue;Data processing module carries out as follows to the local discharge signal for collecting Process:
(1) software filtering and Wavelet Denoising Method are carried out;
(2) time difference of ultrasonic signal and ultrahigh-frequency signal is calculated, substantially fault location is carried out.
Specially:Corresponding with ultrahigh-frequency signal peak value for corresponding for the ultrasonic signal peak value moment moment is subtracted each other, is obtained Ultrasonic signal and the time difference of ultrahigh-frequency signal, this time difference is multiplied by the spread speed of ultrasonic signal, is exactly locally to put Distance of the electricity point with Partial Discharge Detection point.
(3) ultrasound data is carried out point phase window and waveform Adjustable calculation;
Divide phase window mainly to draw for shelf depreciation spectrogram and data are provided, its flow process is:Capture card sample rate is 20MS/ S, acquisition time are 1 power frequency period, and sampling length is often gathered 1 time for 400000 points, i.e. capture card, complete with regard to obtaining 1 400000 data in the power frequency period time.Capture card gathers 2 road signals:1st tunnel is the work of the applying measured by potentiometer Frequency voltage signal, the 2nd tunnel are that the ultrasound wave for being obtained and transmitted by preamplifier and coaxial cable by ultrasonic sensor is believed Number.The data of 2 road signals in this 1 complete power frequency period are each separated into 100 phase windows, then each phase window just has 4000 points, a phase place of each phase window corresponding to power-frequency voltage.
To seeking maximum amplitude per 4000 ultrasonic signals in 1 phase window, if the absolute value of maximum amplitude is more than Set discharge threshold, then illustrate there is shelf depreciation in this phase window, now record the ultrasonic signal most significantly Value, and using this maximum amplitude as the phase window ultrasonic signal amplitude.
To averaging and recording per 4000 voltage signals in 1 phase window.
Waveform is adjusted primarily to making the ultrasonic signal amplitude of 100 phase windows and the phase of the power-frequency voltage for being applied Position opening relationships, i.e.,:1~100 phase window is made to correspond to 0°~360°Phase place, make the ultrasonic signal width of i-th phase window The corresponding sinusoidal wave form i*360 of value°/ 100 phase place.This is because the voltage letter in 1 complete power frequency period of capture card collection Number starting point might not correspond to sine-shaped rising edge zero crossing, so need make adjustment.
Because the voltage signal in 1 complete power frequency period necessarily has rising edge zero crossing, it is possible to sought out Come.Voltage signal rising edge zero crossing the window's position is recorded.
By the ultrasonic signal after voltage signal rising edge zero crossing the window's position toward reach, by voltage signal rising edge Ultrasonic signal before zero crossing the window's position is moved backward, so can be obtained by the ultrasonic signal width of 100 phase windows The relation of the phase place of value and institute's applied voltage.
(4) phase information of ultrasonic shelf depreciation and amplitude information are depicted as amplitude phase spectrum of discharging by spectrogram drafting module Figure (PRPD spectrograms) (Fig. 3), maximum electric discharge amplitude phase spectrogram (Spectrogram) (Fig. 4 a and 4b), averaged discharge amplitude phase Position spectrogram (Spectrogram) (Fig. 5 a and 5b) and discharge time phase place spectrogram (Spectrogram) (Fig. 6), these are typically composed Figure is as shown in figures 3 to 6.
(5) spectrogram of above-mentioned four kinds ultrasonic local discharge signals is carried out statistical nature calculating, extracts and characterize shelf depreciation 27 Statistical Operators of characteristic.
Discharge spectrum shape corresponding to different shelf depreciation types is different, the letter provided using various discharge spectrums Breath, can distinguish various types of electric discharge.But, this difference is only qualitatively, it is necessary to relies on visually and enriches Experience can just be distinguished.Therefore, it is just necessary that some useful statistical parameters are obtained from various discharge spectrums.Sign office The statistical parameter of portion's electric discharge ultrasonic signal is to carry out statistical analysiss to Processing of Partial Discharge Ultrasonic Signals distributed constant, with quantitative Parameter come describe certain distribution shape facility.The statistical parameter for characterizing Processing of Partial Discharge Ultrasonic Signals includes mean μ, standard deviation σ, degree of bias Sk, kurtosis Ku, cross-correlation coefficient cc etc., shown in computing formula such as formula (1)-(5) of these statistical parameters.Using this A little statistical parameters can be identified to electric discharge type.
A) mean μ
xi-- i-th sample;
f(xi)──xiThe probability of appearance;
The number of N -- half period (positive half cycle or negative half period) interior phase window;
B) standard deviation sigma
C) degree of bias Sk
Sk=0 represents that spectrogram is full symmetric, Sk< 0 represents deflection right side, Sk> 0 represents deflection left side;
D) kurtosis Ku
Ku=0 expression projecting degree meets normal distribution, Ku< 0 is represented than the mitigation of normal distribution peak, Ku> 0 is just representing ratio State distribution of peaks is steeper;
E) cross-correlation coefficient cc
In formula:-- i-th sample of positive and negative half cycle;
Cc=1 represents that 100% positive and negative half cycle symmetrical shape, cc=0 represent completely asymmetric.
Mean μ, standard deviation sigma, degree of bias Sk, kurtosis KuIt is both needed to individually calculate by positive and negative half cycle, and cross-correlation coefficient cc is then not Must.So, fromWith27 statistical parameters can be extracted in three kinds of spectrograms altogether.For convenience Represent, 27 statistical parameters are numbered, as shown in table 1.27 statistical parameters constitute the fingerprint of partial discharge model.
The statistical parameter table of 1 ultrasonic local discharge signal of table
6) display module shows the four kinds of discharge spectrums and 27 flash-over characteristic Statistical Operators that draws.
During live live detection, power cable insulation state detection is carried out using the present invention, there is failure or hidden to insulation The power cable of trouble, carries out fault location, characterizes flash-over characteristic, be by way of drawing discharge spectrum and extracting Statistical Operator Site Detection personnel's failure judgement position and fault category provide experimental basis, are the generation for reducing power cable accident, it is ensured that Equipment safety operation is significant.
Description of the drawings
Presently preferred embodiments of the present invention is the foregoing is only, not in order to limit the present invention, all in essence of the invention Any modification, equivalent and improvement that is made within god and principle etc., should be included within the scope of the present invention.

Claims (10)

1. a kind of XLPE power cables partial discharge diagnostic method, it is characterised in that the method includes:
Step 1, gathers ultrasonic signal and the ultrahigh frequency partial discharge signal of the low frequency that power cable shelf depreciation is produced, with spy High frequency partial discharge signal is time reference, calculates the time difference with the ultrasonic signal of low frequency, obtain ultrasonic signal when Between postpone, the spread speed that the time difference of delay is multiplied by ultrasonic local discharge signal obtains shelf depreciation point and shelf depreciation The distance of test point;
Ultrasonic signal is carried out a point phase window by step 2, the maximum amplitude absolute value by ultrasonic signal in phase window with set Fixed discharge threshold compares, and determines there is the phase window of shelf depreciation;
Step 3, ultrasonic signal is carried out after waveform Adjustable calculation, by the ultrasonic signal amplitude of phase window and the work for being applied The phase place opening relationships of frequency voltage;
The phase information of ultrasonic shelf depreciation and amplitude information are depicted as discharge amplitude phase spectrogram, maximum electric discharge width by step 4 Value phase place spectrogram, averaged discharge amplitude phase spectrogram and discharge time phase place spectrogram;
The spectrogram of four kinds of ultrasonic local discharge signals in step 4 is carried out statistical nature calculating, extracts and characterize local by step 5 27 Statistical Operators of flash-over characteristic.
2. according to the XLPE power cable partial discharge diagnostic methods described in claim 1, it is characterised in that step 2 includes:Adopt The power-frequency voltage signal that power cable applying is measured with potentiometer, by power-frequency voltage signal in 1 power frequency period of a collection N number of phase window is each separated into the data of ultrasonic signal, each phase window is M ultrasonic signal and M power-frequency voltage letter Number, a phase place of each phase window corresponding to power-frequency voltage, to asking most significantly per M ultrasonic signal in 1 phase window Value, the absolute value of maximum amplitude is compared with the discharge threshold for setting, and is determined in this phase window whether there is shelf depreciation, is recorded The maximum amplitude of the ultrasonic signal, and using the maximum amplitude as the phase window ultrasonic signal amplitude.
3. according to the XLPE power cable partial discharge diagnostic methods described in claim 2, it is characterised in that step 3 is by ultrasound Ripple signal carries out waveform Adjustable calculation to be included, to averaging per M power-frequency voltage signal in 1 phase window, by phase window Ultrasonic signal amplitude and the phase place opening relationships of power-frequency voltage for being applied, 1~M phase window correspond to 0 °~360 ° Phase place, make the phase place of corresponding i*360 ° of the sinusoidal wave form/M of ultrasonic signal amplitude of i-th phase window.
4. according to the XLPE power cable partial discharge diagnostic methods described in claim 3, it is characterised in that by the super of phase window Acoustic signals amplitude is included with the phase place opening relationships of the power-frequency voltage for being applied:By rising edge mistake in 1 complete power frequency period The voltage signal of zero point takes out, by the ultrasonic signal after voltage signal rising edge zero crossing the window's position toward reach, by electricity Ultrasonic signal before pressure signal rising edge zero crossing the window's position is moved backward, obtain the ultrasonic signal amplitude of phase window with The relation of the phase place of institute's applied voltage.
5. according to the XLPE power cable partial discharge diagnostic methods described in claim 1, it is characterised in that local discharge characteristic Including:Mean μ, standard deviation sigma, degree of bias Sk, kurtosis KuAnd cross-correlation coefficient cc.
6. according to the XLPE power cable partial discharge diagnostic methods described in claim 2, it is characterised in that the parameter of sampling For:Sample rate is 20MS/s, and acquisition time is 1 power frequency period, and sampling length often gathers 1 for 400000 points, i.e. capture card Secondary, just obtain 400000 data in 1 complete power frequency period time.
7. a kind of XLPE power cables partial discharge diagnosis system, it is characterised in that the system includes:
Sonac and superfrequency integrated sensor are respectively used to the ultrasound for gathering the low frequency that power cable shelf depreciation is produced Ripple signal and ultrahigh frequency partial discharge signal;
Signal amplifies and conditioning unit, is amplified conditioning to ultrasonic signal and ultrahigh frequency partial discharge signal;
Capture card, by two channel reception ultrasonic signals and ultrahigh-frequency signal, realizes the Real-time Collection of local discharge signal;
Data processing module, to gathering ultrasonic signal and the superfrequency shelf depreciation of the low frequency that power cable shelf depreciation is produced Signal, with ultrahigh frequency partial discharge signal as time reference, calculates the time difference with the ultrasonic signal of low frequency, obtains ultrasound The time delay of signal, the spread speed that the time difference of delay is multiplied by ultrasonic local discharge signal, obtain shelf depreciation point with The distance of Partial Discharge Detection point;
Ultrasonic signal is carried out a point phase window, by the maximum amplitude absolute value of ultrasonic signal in phase window and putting for setting Electric threshold value compares, and determines there is the phase window of shelf depreciation;
Ultrasonic signal is carried out after waveform Adjustable calculation, by the ultrasonic signal amplitude of phase window and the power-frequency voltage for being applied Phase place opening relationships;
The phase information of ultrasonic shelf depreciation and amplitude information are depicted as the amplitude phase spectrogram, most of discharging by spectrogram drafting module Big electric discharge amplitude phase spectrogram, averaged discharge amplitude phase spectrogram and discharge time phase place spectrogram;
The spectrogram of four kinds of ultrasonic local discharge signals is carried out statistical nature calculating, extracts table by discharge characteristic parametric statisticss module Levy 27 Statistical Operators of Characteristics of Partial Discharge;
Display module, shows the spectrogram of four kinds of ultrasonic local discharge signals.
8. according to the XLPE power cable partial discharge diagnosis systems described in claim 7, it is characterised in that signal amplifies and adjusts Reason unit includes preamplifier, band filter and the buffer circuit being sequentially connected with sonac, and and superfrequency Low-noise amplifier, high pass filter and cymoscope that sensor is sequentially connected;Wherein, the output of preamplifier is filtered with band logical The input of ripple device is connected, and band filter is by the various environment noises unrelated with shelf depreciation ultrasonic signal, mechanical vibration noise Etc. filtering, the output of band filter connects the input of buffer circuit, increases output current.
9. according to the XLPE power cable partial discharge diagnosis systems described in claim 8, it is characterised in that extra-high video sensor Output connect the input of low noise amplifier and be followed by the input of high pass filter, high pass filter handle and partial-discharge ultrahigh-frequency letter Number unrelated low-frequency interference signal is filtered, and the output of high pass filter connects the input of cymoscope, and cymoscope is super high band local Discharge signal moves to low-frequency range.
10. according to the XLPE power cable partial discharge diagnosis systems described in claim 7, it is characterised in that capture card is sampled Rate is 20MS/s, and acquisition time is 1 power frequency period, and sampling length is often gathered 1 time for 400000 points, i.e. capture card, just obtained Obtain 400000 data in 1 complete power frequency period time.
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Cited By (13)

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CN107153154A (en) * 2017-06-14 2017-09-12 中国矿业大学 A kind of two sides earth cable insulation deterioration diagnosis method
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CN107765152A (en) * 2017-10-23 2018-03-06 南京联能电力检测研究所有限公司 The method that shelf depreciation positioning is carried out using coefficient correlation and Newton-Laphson method
CN107831412A (en) * 2017-10-11 2018-03-23 国网上海市电力公司 Local discharge of electrical equipment localization method and system, storage medium and terminal device
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CN108896879A (en) * 2018-05-15 2018-11-27 国网江苏省电力有限公司电力科学研究院 Diagnosis atlas phase windowing parameter regulation means based on local discharge signal feature
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CN110031733A (en) * 2019-04-16 2019-07-19 国网江苏省电力有限公司电力科学研究院 Detection method for local discharge and system
CN110161386A (en) * 2019-05-06 2019-08-23 贵州电网有限责任公司 A kind of portable high-pressure cable connector local discharge detection device and method
CN110568324A (en) * 2019-08-06 2019-12-13 北京三清互联科技有限公司 GIS partial discharge online monitoring system and method
CN110632479A (en) * 2019-11-03 2019-12-31 西南交通大学 EPR cable insulation performance evaluation method based on discharge capacity normalized transformation

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CN106707128A (en) * 2017-03-16 2017-05-24 国家电网公司 Acoustoelectric associated local cable discharge locating device and method
CN106950482A (en) * 2017-05-09 2017-07-14 广东电网有限责任公司珠海供电局 A kind of corona ELIMINATION OF ITS INTERFERENCE method based on alternate signal collection of illustrative plates similarity relation
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CN107153154A (en) * 2017-06-14 2017-09-12 中国矿业大学 A kind of two sides earth cable insulation deterioration diagnosis method
CN107153154B (en) * 2017-06-14 2019-11-01 中国矿业大学 A kind of two sides earth cable insulation deterioration diagnosis method
CN107505543A (en) * 2017-08-11 2017-12-22 河南天通电力有限公司 Based on mesolow cable local discharge on-line monitoring system
CN107831412A (en) * 2017-10-11 2018-03-23 国网上海市电力公司 Local discharge of electrical equipment localization method and system, storage medium and terminal device
CN107831412B (en) * 2017-10-11 2020-02-21 国网上海市电力公司 Electrical equipment partial discharge positioning method and system, storage medium and terminal equipment
CN107765152A (en) * 2017-10-23 2018-03-06 南京联能电力检测研究所有限公司 The method that shelf depreciation positioning is carried out using coefficient correlation and Newton-Laphson method
CN108896879A (en) * 2018-05-15 2018-11-27 国网江苏省电力有限公司电力科学研究院 Diagnosis atlas phase windowing parameter regulation means based on local discharge signal feature
CN108896879B (en) * 2018-05-15 2020-02-04 国网江苏省电力有限公司电力科学研究院 Diagnostic map phase windowing parameter adjusting method based on partial discharge signal characteristics
CN108802583A (en) * 2018-06-26 2018-11-13 西安开天电气可靠性实验室有限公司 A kind of electric railway high pressure feeder cable partial discharge monitoring method
CN109490730A (en) * 2018-12-19 2019-03-19 国网北京市电力公司 Cable discharge detection method, device, storage medium and processor
CN110031733A (en) * 2019-04-16 2019-07-19 国网江苏省电力有限公司电力科学研究院 Detection method for local discharge and system
CN110161386A (en) * 2019-05-06 2019-08-23 贵州电网有限责任公司 A kind of portable high-pressure cable connector local discharge detection device and method
CN110568324A (en) * 2019-08-06 2019-12-13 北京三清互联科技有限公司 GIS partial discharge online monitoring system and method
CN110632479A (en) * 2019-11-03 2019-12-31 西南交通大学 EPR cable insulation performance evaluation method based on discharge capacity normalized transformation
CN110632479B (en) * 2019-11-03 2020-09-29 西南交通大学 EPR cable insulation performance evaluation method based on discharge capacity normalized transformation

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