CN107167693B - A kind of resistive current of gapless metal-oxide lighting arrester inversion method and device - Google Patents
A kind of resistive current of gapless metal-oxide lighting arrester inversion method and device Download PDFInfo
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- CN107167693B CN107167693B CN201710374284.4A CN201710374284A CN107167693B CN 107167693 B CN107167693 B CN 107167693B CN 201710374284 A CN201710374284 A CN 201710374284A CN 107167693 B CN107167693 B CN 107167693B
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- 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
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
- G01R19/2506—Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values ; Details concerning sampling, digitizing or waveform capturing
- G01R19/2509—Details concerning sampling, digitizing or waveform capturing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
- G01R19/252—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques using analogue/digital converters of the type with conversion of voltage or current into frequency and measuring of this frequency
Abstract
The invention discloses a kind of resistive current of gapless metal-oxide lighting arrester inversion method and devices, wherein, the resistive current of gapless metal-oxide lighting arrester inversion method includes: to carry out data acquisition to arrester by current transformer and bandpass filter, obtains full leakage current signal；Strong jamming is carried out to full leakage current signal and filters out operation, obtains arrester triple harmonic current；According to preset time starting point and full leakage current signal, total current phase angle is obtained, then arrester triple harmonic current and total current phase angle are carried out that current in resistance property is calculated.The present invention uses weak signal extraction technology and interference filter algorithm under the conditions of high precision current transformer, strong jamming, improve test accuracy, and use targeted algorithm, the triple-frequency harmonics data measured to scene are handled, lightning arrester resistance component is obtained by counter push away of triple-frequency harmonics, obtains characteristic quantity data for the quantization judgement of arrester performance.
Description
Technical field
The present invention relates to arrester resistance current fields of measurement more particularly to a kind of gapless metal-oxide lighting arrester to hinder
Property electric current inversion method and device.
Background technique
Arrester is as overvoltage protection, and operating status is for power system security reliability service, support personnel
Safety is extremely important.Arrester bears system working voltage and in short-term overvoltage for a long time, different from high voltage equipment insulation, influences to keep away
The factor of thunder device state is active loss, including dampness and resistor disc active loss, once fever caused by resistor disc deterioration is super
Its heat-sinking capability is crossed, the thermal balance of arrester will be destroyed, and eventually lead to thermal runaway and damage, therefore it is active to characterize arrester
The current in resistance property of loss becomes the most critical index for measuring arrester state.
Preventive trial is a key link of arrester operation and maintenance, power industry standard DL/T596-1996
" power equipment preventive trial regulation " specifies arrester power failure preventive trial project, period and requirement, is always lightning-arrest
The main means of device operation and maintenance.The power failure DC leakage-current test of arrester is very quick for discovery arrester early defect
Sense and effectively, but period power failure preventive trial low efficiency, at high cost is existed simultaneously, with power grid high speed development and power supply reliability
Requirement between contradiction it is more and more prominent.With the maturation of gapless metal-oxide lighting arrester live testing technology, have
It is on the waiting list the technological means for the test of power failure DC leakage-current, " electric power is set south electric network company standard Q/CSG114002-2011
Standby preventive trial regulation " live testing has been combined with infrared thermal imaging detection as arrester preventive trial primary hand
Section.
The leakage current equivalent circuit of arrester is monitored as shown in Figure 1, wherein C is arrester stray capacitance over the ground, R is to keep away
Thunder device zinc oxide resistance sheet nonlinear resistance, IcIt is capacity current caused by stray capacitance, IRIt is by arrester zinc oxide resistance sheet
Current in resistance property caused by nonlinear resistance.Total earth leakage electric current (hereinafter referred to as " total current ") I of arrestertThen by resistive
It is superimposed and constitutes with capacitive leakage current:
It=Ic+IR
Wherein capacity current is influenced smaller by arrester operating status, and the close phase of operating status of current in resistance property arrester
It closes, reflects the active loss of arrester resistor disc and built-in electrical insulation, be the main indicator for evaluating arrester operating status quality.
Due to capacity current IcMuch larger than current in resistance property IR, from total current ItAmplitude be difficult to accurately reflect current in resistance property
Variation, and therefore can not effectively obtain arrester operating status.Therefore it needs to decouple capacitive and current in resistance property, solve at present
The main stream approach of this problem is capacitive current compensation method (or being " phase voltage penalty method "), and this method needs additional measurement to apply
The voltage signal being added on arrester, by 90 ° of the voltage signal phase shift and the amplitude of accommodation obtains equivalent capacity current, Cong Quan electricity
The capacitive ingredient is deducted in stream signal and obtains resistive current component, and arrester internal wetted and electricity are obtained according to its size variation
Hinder the latent defects such as piece aging.
Capacitive current compensation method needs complicated analog signal translation circuit, and needs at the scene to mention voltage signal
It takes, at the scene inconvenience and disadvantage present in implementation, furthermore from the sampling of system voltage mutual inductor secondary side, there are voltage transformers
The risk of secondary circuit short-circuit, whether the insulation that voltage signal sampling folder is had to check for before test is good, and the voltage of test equipment takes
Sample circuit must install optical isolation (voltage isolator), prevent voltage transformer in cabinet (or capacitance type potential transformer)
Secondary circuit short-circuit.
In the capacitive current compensation method test practice for accounting for mainstream, because of security reason, voltage transformer secondary signal is not taken,
Or transfer to take and stand with (maintenance power supply) reference voltage is become, due to the winding transform part through being missed the stop with change, phase angle is displaced, with
This, which compensates capacitance current, to bring biggish original reason error to current in resistance property measurement result, is unable to get accurate ground resistance
Property electric current, mostly the arrester of measurement result exception can only be issued and accused by the lateral comparison of three-phase lightning protector test result
It is alert, it is aided with infrared thermal imaging image and is confirmed, final needs carries out DC leakage-current test by power failure and confirmed；Nothing
Method diagnoses arrester early defect, at batch, there are the arresters of familial defect, it is also difficult to pass through lateral ratio
Compared with and reflect the development of defect, or even there is the problem of erroneous judgement, fail to judge, affect live testing technology and arrester defect is examined
Disconnected validity.
For improve arrester operation and maintenance level, comply with status of electric power evaluation development trend, it is necessary to improve with
Live testing technology based on arrester resistance current acquisition, lacks particularly with because of no counter or leakage current detection device
The 35kV and following voltage class arrester of few O&M means, with greater need for the operation and maintenance test for arrester provide simply and
Accurate solution.
Therefore it provides a kind of resistive current of gapless metal-oxide lighting arrester inverting side based on total current harmonic wave vector
Method and device are those skilled in the art's technical issues that need to address.
Summary of the invention
The embodiment of the invention provides a kind of resistive current of gapless metal-oxide lighting arrester inversion method and devices, can
Realize accurate extraction to current in resistance property and harmonic current components, realize the correct diagnosis of arrester state, for it is safe and simple,
It efficiently and accurately carries out arrester O&M and provides support.
The embodiment of the invention provides a kind of resistive current of gapless metal-oxide lighting arrester inversion methods, comprising:
S1: data acquisition is carried out to arrester by current transformer and bandpass filter, obtains full leakage current signal；
S2: strong jamming is carried out to full leakage current signal and filters out operation, obtains arrester triple harmonic current；
S3: according to preset time starting point and full leakage current signal, total current phase angle is obtained, then humorous three times to arrester
Wave electric current and total current phase angle carry out that current in resistance property is calculated.
Preferably, step S1 is specifically included:
Data acquisition is carried out to arrester by high-precision current transformer, preliminary current signal is obtained, to preliminary electricity
Stream signal is converted and is amplified, and voltage signal is obtained；
It passes sequentially through bandpass filter, peak detection circuit, correcting circuit and DSP and voltage signal is handled to obtain entirely
Leakage current signal.
Preferably, step S2 is specifically included:
Criterion is maximized according to Signal Interference and Noise Ratio and establishes interference blocking matched filter, is matched and is filtered by interference blocking
The interference that wave device carries out different spectral feature to full leakage current signal filters out operation, and the full leakage after obtaining interference filtering is electric
Flow signal；
The full leakage current signal after interference filtering is carried out by Independent Component Analysis Algorithm and algorithm of principal component analysis
Strong jamming filters out operation, obtains the full leakage current signal after strong jamming filters out；
Full leakage current signal after being filtered out by Modern spectral estimation algorithm to strong jamming carries out harmonic wave extraction operation, obtains
Arrester triple harmonic current.
Preferably, step S3 is specifically included:
Fundamental voltage corresponding with full leakage current signal is got, and is believed according to preset time starting point and full leakage current
Number, obtain total current phase angle；
According to the phase corresponding relationship between full leakage current signal and fundamental voltage, by total current phase angle, keep away
The phase of thunder device triple harmonic current carries out that fundamental voltage phase is calculated；
Fourier decomposition is carried out to full leakage current signal according to fundamental voltage phase, obtains capacity current, then will let out entirely
Leakage current signal subtracts capacity current and obtains current in resistance property.
Preferably, bandpass filter is the multiple negative-feedback bandwidth-limited circuit of six ranks.
Preferably, the embodiment of the invention also provides a kind of resistive current of gapless metal-oxide lighting arrester inverting dresses
It sets, comprising:
Acquisition unit is let out entirely for carrying out data acquisition to arrester by current transformer and bandpass filter
Leakage current signal；
Unit is filtered out, filters out operation for carrying out strong jamming to full leakage current signal, obtains arrester triple-frequency harmonics electricity
Stream；
Computing unit, for according to preset time starting point and full leakage current signal, obtaining total current phase angle, then to keeping away
Thunder device triple harmonic current and total current phase angle carry out that current in resistance property is calculated.
Preferably, acquisition unit specifically includes:
Subelement is acquired, for carrying out data acquisition to arrester by high-precision current transformer, obtains preliminary electricity
Signal is flowed, preliminary current signal is converted and amplified, voltage signal is obtained；
Subelement is handled, voltage is believed for passing sequentially through bandpass filter, peak detection circuit, correcting circuit and DSP
It number is handled to obtain full leakage current signal.
Preferably, unit is filtered out to specifically include:
First filters out subelement, establishes interference blocking matched filtering for maximizing criterion according to Signal Interference and Noise Ratio
Device filters out operation by the interference that interference blocking matched filter carries out different spectral feature to full leakage current signal, obtains
Full leakage current signal after to interference filtering；
Second filters out subelement, after passing through Independent Component Analysis Algorithm and algorithm of principal component analysis to interference filtering
Full leakage current signal carries out strong jamming and filters out operation, obtains the full leakage current signal after strong jamming filters out；
Subelement is extracted, is carried out for the full leakage current signal after being filtered out by Modern spectral estimation algorithm to strong jamming humorous
Wave extraction operation obtains arrester triple harmonic current.
Preferably, computing unit specifically includes:
First obtains subelement, for getting fundamental voltage corresponding with full leakage current signal, and according to it is preset when
Between starting point and full leakage current signal, obtain total current phase angle；
Second obtains subelement, for leading to according to the phase corresponding relationship between full leakage current signal and fundamental voltage
It crosses and the phase at total current phase angle, arrester triple harmonic current is carried out that fundamental voltage phase is calculated；
Computation subunit is held for carrying out fourier decomposition to full leakage current signal according to fundamental voltage phase
Property electric current, then full leakage current signal is subtracted into capacity current and obtains current in resistance property.
Preferably, bandpass filter is the multiple negative-feedback bandwidth-limited circuit of six ranks.
As can be seen from the above technical solutions, the embodiment of the present invention has the advantage that
The embodiment of the invention provides a kind of resistive current of gapless metal-oxide lighting arrester inversion method and device,
In, the resistive current of gapless metal-oxide lighting arrester inversion method characterized by comprising S1: pass through current transformer
Data acquisition is carried out to arrester with bandpass filter, obtains full leakage current signal；S2: full leakage current signal is carried out strong
Interference filtering operation, obtains arrester triple harmonic current；S3: it according to preset time starting point and full leakage current signal, obtains
Total current phase angle, then arrester triple harmonic current and total current phase angle are carried out that current in resistance property is calculated.The present invention
Embodiment is mentioned using weak signal extraction technology and interference filter algorithm under the conditions of high precision current transformer (CT), strong jamming
High test accuracy, and targeted algorithm is used, the triple-frequency harmonics data measured to scene are handled, by three times
Counter push away of harmonic wave obtains lightning arrester resistance component, obtains characteristic quantity data for the quantization judgement of arrester performance.
Further, circuital noncontacting measurement is realized by current transformer (CT), adapts to the 35kV having a large capacity and a wide range
And following arrester does not configure the design feature of counter or bleeder current measurer, solves 35kV without counter and following
Arrester lacks the problem of O&M means, reduces unnecessary power failure test job amount, improves power distribution network reliability of operation.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention without any creative labor, may be used also for those of ordinary skill in the art
To obtain other attached drawings according to these attached drawings.
Fig. 1 is a kind of stream of resistive current of gapless metal-oxide lighting arrester inversion method provided in an embodiment of the present invention
Journey schematic diagram；
Fig. 2 is a kind of the another of resistive current of gapless metal-oxide lighting arrester inversion method provided in an embodiment of the present invention
One flow diagram；
Fig. 3 is a kind of knot of resistive current of gapless metal-oxide lighting arrester inverting device provided in an embodiment of the present invention
Structure schematic diagram；
Fig. 4 is gapless metal-oxide lighting arrester equivalent circuit schematic；
Fig. 5 is the characteristic schematic diagram of gapless metal-oxide lighting arrester typical case V-I；
Fig. 6 is the full leakage current sampling system schematic diagram using bandpass filter；
Fig. 7 is the multiple negative-feedback bandwidth-limited circuit figure of six ranks.
Specific embodiment
The embodiment of the invention provides a kind of resistive current of gapless metal-oxide lighting arrester inversion method and devices, can
Realize accurate extraction to current in resistance property and harmonic current components, realize the correct diagnosis of arrester state, for it is safe and simple,
It efficiently and accurately carries out arrester O&M and provides support.
In order to make the invention's purpose, features and advantages of the invention more obvious and easy to understand, below in conjunction with the present invention
Attached drawing in embodiment, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that disclosed below
Embodiment be only a part of the embodiment of the present invention, and not all embodiment.Based on the embodiments of the present invention, this field
Those of ordinary skill's all other embodiment obtained without making creative work, belongs to protection of the present invention
Range.
Referring to Fig. 1, a kind of resistive current of gapless metal-oxide lighting arrester inverting side provided in an embodiment of the present invention
One embodiment of method, comprising:
101, data acquisition is carried out to arrester by current transformer and bandpass filter, obtains full leakage current letter
Number；
Leakage current collection is carried out to the arrester with acquisition by high-precision current transformer, collects initial let out
After leakage current, preliminary interference signal is carried out to the leakage current by bandpass filter and filters out that (bandpass filter is really
The extraction of fundamental current and triple harmonic current is carried out to the initial leakage current), obtain full leakage current.
102, strong jamming is carried out to full leakage current signal and filters out operation, obtain arrester triple harmonic current；
After obtaining full leakage current signal, which further comprises a variety of environment high reject signals, therefore also needs to carry out more
Secondary strong jamming filters out operation, obtains arrester triple harmonic current.
103, according to preset time starting point and full leakage current signal, total current phase angle is obtained, then three times to arrester
Harmonic current and total current phase angle carry out that current in resistance property is calculated.
By the way that a start time is arranged, then according to its available total current phase angle of full leakage current signal, then it is right
Arrester triple harmonic current and total current phase angle carry out Inversion Calculation and obtain current in resistance property.
Referring to Fig. 2, a kind of resistive current of gapless metal-oxide lighting arrester inverting side provided in an embodiment of the present invention
Another embodiment of method, comprising:
201, data acquisition is carried out to arrester by high-precision current transformer, preliminary current signal is obtained, to first
Step current signal is converted and is amplified, and voltage signal is obtained；
202, bandpass filter, peak detection circuit, correcting circuit and DSP are passed sequentially through, voltage signal handle
To full leakage current signal；
203, criterion is maximized according to Signal Interference and Noise Ratio and establishes interference blocking matched filter, pass through interference blocking
The interference for carrying out different spectral feature to full leakage current signal with filter filters out operation, and complete after obtaining interference filtering being let out
Leakage current signal；
204, by Independent Component Analysis Algorithm and algorithm of principal component analysis to the full leakage current signal after interference filtering
It carries out strong jamming and filters out operation, obtain the full leakage current signal after strong jamming filters out；
205, the full leakage current signal after being filtered out by Modern spectral estimation algorithm to strong jamming carries out harmonic wave extraction operation,
Obtain arrester triple harmonic current；
206, fundamental voltage corresponding with full leakage current signal is got, and according to preset time starting point and full leakage electricity
Signal is flowed, total current phase angle is obtained；
207, according to the phase corresponding relationship between full leakage current signal and fundamental voltage, by total current phase
Angle, arrester triple harmonic current phase carry out that fundamental voltage phase is calculated；
208, fourier decomposition is carried out to full leakage current signal according to fundamental voltage phase, obtains capacity current, then will
Full leakage current signal subtracts capacity current and obtains current in resistance property.
The embodiment of the present invention is using weak signal extraction technology under the conditions of high precision current transformer (CT), strong jamming and does
Filtering algorithm is disturbed, improves test accuracy, and use targeted algorithm, the triple-frequency harmonics data that scene measures are carried out
Processing, obtains lightning arrester resistance component by counter push away of triple-frequency harmonics, obtains characteristic quantity data for the quantization judgement of arrester performance.
Further, circuital noncontacting measurement is realized by current transformer (CT), adapts to the 35kV having a large capacity and a wide range
And following arrester does not configure the design feature of counter or bleeder current measurer, solves 35kV without counter and following
Arrester lacks the problem of O&M means, reduces unnecessary power failure test job amount, improves power distribution network reliability of operation.
The above is the detailed description carried out to a kind of resistive current of gapless metal-oxide lighting arrester inversion method, for just
In understanding, a kind of resistive current of gapless metal-oxide lighting arrester inversion method will be answered with a concrete application scene below
With being illustrated, application examples includes:
The application example test object is gapless metal-oxide lighting arrester, isopleth map such as Fig. 4, to be with distribution capacity
Main capacitor C is in parallel with nonlinear resistive element R, and for U-I characteristic as shown in figure 5, theoretically, U-I characteristic curve can be with
It is indicated with multinomial (1):
ir=∑ AiUi(i=1,3,5 ...) (1)
The application example discusses 2 kinds of situations:
Situation one:
ir=A1U+A3U3 (2)
It enables and applies voltage for sinusoidal voltage, i.e.,Substitution formula (2) arrangement obtains:
In formula:ψ1=ψ,ψ3=3ψ。
It can be seen that will appear 3 subharmonic currents,
Situation two:
ir=A1U+A5U5 (4)
It willSubstitution formula (4) arrangement obtains:
In formula:ψ1=ψ,ψ3=3 ψ,ψ5=5ψ。
It can be seen that also will appear 3 subharmonic currents
See from formula (3) and (5), as long as arrester resistance R certainly exists 3 in current in resistance property there are non-linear i.e. i >=3
Order harmonic components.From K3See in expression formula: K3、K5Bigger, i.e., non-linear stronger, 3 order harmonic components are bigger；That is ir3With
Nonlinear factor K3、K5It is directly proportional.Triple harmonic current phase Ψ3With voltage-phase Ψ at certain relationship, therefore from ir3Phase angle
Ψ3It can get voltage phase angle Ψ.Theoretically, 1 50Hz dfundamental-harmonic pair answers the waveform of 3 triple-frequency harmonics, 1 triple-frequency harmonics therein
Zero crossing is overlapped with fundamental wave zero crossing, i.e. " same to phase ", and another two differs 120 ° and 60 ° (or 240 °) with fundamental wave respectively, also that is, logical
The phase of measurement triple-frequency harmonics is crossed, the phase angle that can extrapolate fundamental wave there are 3 kinds of possible outcomes.And it is known that the phase of fundamental wave and complete
The phase phase difference of electric current close to 90 °, then correctly tie by the fundamental voltage phase that we can easily be determined for compliance with this requirement
Fruit.
After obtaining the phase of fundamental voltage, fourier decomposition is carried out by total current, capacity current vector can be obtained, then
Subtracting capacity current with total current can be obtained current in resistance property.
In view of the relatively forceful electric power factory interference environment of live live testing, which needs to solve to sentence from on-the-spot test signal
Not different interference signal characteristics, targetedly filters out interference, additionally needs in required harmonic signal power hundreds of times
Under even thousands of times of capacity current interference, the accurate amplitude and phase characteristic for analyzing harmonic component, improve it is traditional three times
Algorithm of harmonics analysis decomposes capacity current, the non-linear resistive leakage current of resistor disc and due to dampness and dust accumulation under strong jamming
Bring current component.Since uncertainty of the extracted parameter characteristic to measurement error and measurement result has very big shadow
It rings, therefore has high requirement to the performance of algorithm.
In order to realize the signal precise measurement particular harmonic low current vector under thousands of times of strong jammings, need in signal extraction
Anti-Jamming Technique measure is taken with signal analysis two links of inverting, the method for the present invention is specifically includes the following steps: T1 is to pass through
Bandpass filter realizes the extraction to full leakage current signal.T2 is such as matched using the interference blocking for interference spectrum characteristic
Filter Anti-interference algorithm, for " blind separation " algorithm of mixed signal or for signal spectrum under interference/noise environment towards resolution
Modern times " Power estimation " algorithm etc. of rate analysis, filters out the strong jamming in total current measurement signal, it is humorous three times to obtain arrester electric current
Wave component；T3 is the relationship according to triple harmonic current phase and voltage-phase, obtains current in resistance property by inverting.
Application examples hardware realization of the present invention is simple, and field conduct is convenient, overcomes traditional live testing engineering test program
Complexity, heavy workload, anti-interference ability is weaker, accuracy is low, and the higher problem of security risk, can relatively accurately obtain
Reflect the current in resistance property of arrester operating status.
Step T1 realizes the acquisition of full leakage current signal.It is realized using low distortion current transformer (CT), for configuration
The current sampling unit for being temporarily connected in parallel on counter both ends can also be used, so in the arrester of counter or bleeder current measurer
Interference signal in total current is filtered out by bandpass filter realization afterwards.
Since the leakage current of arrester is all often mA grades, and current in resistance property only accounts for circuital 10%~20%, resistance
Property electric current in third-harmonic component be even more may there was only A grade of μ, so very to the sampling precision requirement of leakage current of an arrester
Height, and be the precondition for guaranteeing accurately to measure arrester resistance current to the accurate acquisition of leakage current of an arrester.
T1-1 carries out full leakage current sampling using high-precision current transformer, and collected current signal is converted into
Voltage signal is simultaneously subject to suitably amplification (1000 times of amplification, i.e., subsequent gained output data/V correspondence/mA) so as to subsequent progress three
Subharmonic bandpass filtering.Since the bandwidth of filtering is small, bound cutoff frequency is relatively close, should not be adopted as individual low pass with
High-pass filter is realized, therefore, centre frequency is used to examine for six ranks of 100Hz multiple negative-feedback bandwidth-limited circuits and peak value
Slowdown monitoring circuit and correcting circuit realize the measurement of leakage current of an arrester, carry out digital processing to institute's measured data finally by DSP
It is analyzed, sampling system schematic diagram is as shown in Figure 6.
The multiple negative-feedback bandwidth-limited circuit of six rank of T1-2, will be complete as shown in fig. 7, take centre frequency 100Hz bandwidth 80Hz
Fundamental wave and triple-frequency harmonics in leakage current extract.The six ranks circuit is made of three second-order circuits, the biography of second-order circuit
Delivery function are as follows:
The transmission function of six rank bandwidth-limited circuits are as follows:
Resistance and capacitor appropriate are selected, realizes bandpass filtering.
T1-3 collects after full current signal the start time, it is specified that unified, obtains circuital phase angle.
Step T2 filters out the strong jamming in total current measurement signal, it is humorous three times to obtain arrester electric current by many algorithms
Wave component.
The full leakage current signal that T2-1 obtains S1 by total current acquisition unit, for the common dry of site environment
It disturbs, designs corresponding matched filtering algorithm, for the interference of different spectral feature, according to SINR (Signal Interference and Noise Ratio) maximum
Change criterion, injects matched filter techniques using interference, establish corresponding interference blocking matched filter, it is of interest not injuring
Under the wall of characteristics of signals, ambient noise is reduced as far as possible.
T2-2 is other than using interference injection matched filter techniques to interference, for useful signal, it is contemplated that signal
In capacitive ingredient and resistive composition between the characteristics of mixing, select " blind separation " technology, this technology depends on non-gaussian type
High-order statistic information in signal, distinguishes different signal components, relevant algorithm include " independent component analysis " (ICA) and
Non-linear " principal component analysis " algorithm.Using the final unlike signal ingredient of mixed signal statistical iteration or uncorrelated nature into
Row separation.Relevant algorithm is weak under the strong jammings such as bioelectrical signals detection, audio signal separation, faint wireless signal acquisition
Signal detection field is used widely, and algorithm feasibility is guaranteed.
T2-3 improves harmonic wave resolution capability in order to improve harmonic wave resolution capability, using " Modern spectral estimation " algorithm, passes through letter
Work song spatial model, direct estimation harmonic wave vector characteristics parameter therein, since Power estimation algorithm is differentiated in short signal frequency spectrum
Advantage in terms of power, so that it is highly suitable for high-precision harmonic wave vector measurement and analysis.
Step T3 is the relationship according to triple harmonic current phase and voltage-phase, obtains current in resistance property by inverting.
T3-1 answers the waveform of 3 triple-frequency harmonics according to the correspondence of fundamental wave and triple-frequency harmonics waveform, 1 50Hz dfundamental-harmonic pair,
1 triple-frequency harmonics zero crossing therein is overlapped with fundamental wave zero crossing, i.e. " same to phase ", another two differed respectively with fundamental wave 120 ° and
60 ° (or 240 °), also that is, the triple-frequency harmonics phase obtained by S2, can extrapolate 3 kinds of possible results of phase angle of fundamental wave.
T3-2 according to the phase of fundamental voltage (i.e. system voltage) with circuital phase phase difference usually close to 90 °, then may be used
To be readily determined the fundamental voltage phase correct result for meeting this requirement.
The fundamental voltage phase that T3-3 is obtained according to T3-2 carries out fourier by total current and decomposes to get electric to capacitive
Flow vector.
T3-4, which finally subtracts capacity current with total current, can be obtained current in resistance property.
The principle of the arrester resistance current measurement method of the application example determines in its test process without having a power failure, being not necessarily to
Voltage transformer secondary terminal voltage signal is extracted, by flowing through the circuital contactless easy measurement of lightning arrester body, is passed through
Inverting obtains the current in resistance property of reflection arrester state and the triple harmonic current of reflection resistor disc deterioration state, greatly simplifies
Field test procedures carries out extracting voltage transformer secondary terminal voltage signal without original related relay protection professional technician
Cooperation farthest reduces workload, test difficulty and security risk, eliminates and cause to pacify to power grid due to misoperation
Full hidden danger.Major technique advantage:
(1) it is calculated by weak signal extraction technology under the conditions of high precision current transformer (CT), strong jamming and interference filter
Method improves test accuracy.
(2) targeted algorithm is used, the triple-frequency harmonics data measured to scene are handled, anti-by triple-frequency harmonics
It pushes away and obtains lightning arrester resistance component, obtain characteristic quantity data for the quantization judgement of arrester performance.
(3) circuital noncontacting measurement is realized by current transformer (CT), adapts to the 35kV having a large capacity and a wide range and following
Arrester does not configure the design feature of counter or bleeder current measurer, solves 35kV and following arrester without counter
The problem for lacking O&M means reduces unnecessary power failure test job amount, improves power distribution network reliability of operation.
Testing current in resistance property of lightning arrester method of the invention can find arrester latent defect in time, by arrester event
Barrier eliminates the trend requirement that status of electric power detection and repair based on condition of component have been complied in budding state, economic benefit and society's effect
It is beneficial significant.
Original reason test is carried out in high-potting hall and certain 220kV substation, using the arrester total current of development
Harmonic component sampling apparatus has carried out sampling analysis and has carried out inverting, obtains current in resistance property, surveys with using the general China AI6106 in Jinan
The measurement result that test system extracts the capacitive current compensation method of testing transformer secondary winding voltage signal is compared, such as table one
With shown in table two, two methods measurement result is almost the same.
One high pressure hall of table carries out test the data obtained to arrester
Certain the 220V transformer substation arrester live testing data of table two
Referring to Fig. 3, a kind of resistive current of gapless metal-oxide lighting arrester inverting dress provided in an embodiment of the present invention
The one embodiment set, comprising:
Acquisition unit 301 obtains complete for carrying out data acquisition to arrester by current transformer and bandpass filter
Leakage current signal；
Unit 302 is filtered out, operation is filtered out for carrying out strong jamming to full leakage current signal, obtains arrester triple-frequency harmonics
Electric current；
Computing unit 303 is used to obtain total current phase angle according to preset time starting point and full leakage current signal, then
Arrester triple harmonic current and total current phase angle are carried out that current in resistance property is calculated.
Further, acquisition unit 301 specifically includes:
Subelement 3011 is acquired, for carrying out data acquisition to arrester by high-precision current transformer, is obtained just
Current signal is walked, preliminary current signal is converted and amplified, voltage signal is obtained；
Subelement 3012 is handled, for passing sequentially through bandpass filter, peak detection circuit, correcting circuit and DSP to electricity
Pressure signal is handled to obtain full leakage current signal.
Further, unit 302 is filtered out to specifically include:
First filters out subelement 3021, establishes interference blocking matching filter for maximizing criterion according to Signal Interference and Noise Ratio
Wave device filters out operation by the interference that interference blocking matched filter carries out different spectral feature to full leakage current signal,
Full leakage current signal after obtaining interference filtering；
Second filters out subelement 3022, for passing through Independent Component Analysis Algorithm and algorithm of principal component analysis to interference filtering
Full leakage current signal afterwards carries out strong jamming and filters out operation, obtains the full leakage current signal after strong jamming filters out；
Extract subelement 3023, for the full leakage current signal after being filtered out by Modern spectral estimation algorithm to strong jamming into
Row harmonic wave extraction operation, obtains arrester triple harmonic current.
Further, computing unit 303 specifically includes:
First obtains subelement 3031, for getting fundamental voltage corresponding with full leakage current signal, and according to pre-
Start time and full leakage current signal are set, total current phase angle is obtained；
Second obtains subelement 3032, for closing according to the phase between full leakage current signal and fundamental voltage is corresponding
System, carries out that fundamental voltage phase is calculated by the phase to total current phase angle, arrester triple harmonic current；
Computation subunit 3033 is obtained for carrying out fourier decomposition to full leakage current signal according to fundamental voltage phase
To capacity current, then full leakage current signal is subtracted into capacity current and obtains current in resistance property.
Further, bandpass filter is the multiple negative-feedback bandwidth-limited circuit of six ranks.
It is apparent to those skilled in the art that for convenience and simplicity of description, the system of foregoing description,
The specific work process of device and unit, can refer to corresponding processes in the foregoing method embodiment, and details are not described herein.
In several embodiments provided herein, it should be understood that disclosed system, device and method can be with
It realizes by another way.For example, the apparatus embodiments described above are merely exemplary, for example, the unit
It divides, only a kind of logical function partition, there may be another division manner in actual implementation, such as multiple units or components
It can be combined or can be integrated into another system, or some features can be ignored or not executed.Another point, it is shown or
The mutual coupling, direct-coupling or communication connection discussed can be through some interfaces, the indirect coupling of device or unit
It closes or communicates to connect, can be electrical property, mechanical or other forms.
The unit as illustrated by the separation member may or may not be physically separated, aobvious as unit
The component shown may or may not be physical unit, it can and it is in one place, or may be distributed over multiple
In network unit.It can select some or all of unit therein according to the actual needs to realize the mesh of this embodiment scheme
's.
It, can also be in addition, the functional units in various embodiments of the present invention may be integrated into one processing unit
It is that each unit physically exists alone, can also be integrated in one unit with two or more units.Above-mentioned integrated list
Member both can take the form of hardware realization, can also realize in the form of software functional units.
If the integrated unit is realized in the form of SFU software functional unit and sells or use as independent product
When, it can store in a computer readable storage medium.Based on this understanding, technical solution of the present invention is substantially
The all or part of the part that contributes to existing technology or the technical solution can be in the form of software products in other words
It embodies, which is stored in a storage medium, including some instructions are used so that a computer
Equipment (can be personal computer, server or the network equipment etc.) executes the complete of each embodiment the method for the present invention
Portion or part steps.And storage medium above-mentioned includes: USB flash disk, mobile hard disk, read-only memory (ROM, Read-Only
Memory), random access memory (RAM, Random Access Memory), magnetic or disk etc. are various can store journey
The medium of sequence code.
The above, the above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations；Although referring to before
Stating embodiment, invention is explained in detail, those skilled in the art should understand that: it still can be to preceding
Technical solution documented by each embodiment is stated to modify or equivalent replacement of some of the technical features；And these
It modifies or replaces, the spirit and scope for technical solution of various embodiments of the present invention that it does not separate the essence of the corresponding technical solution.
Claims (8)
1. a kind of resistive current of gapless metal-oxide lighting arrester inversion method characterized by comprising
S1: data acquisition is carried out to arrester by current transformer and bandpass filter, obtains full leakage current signal；
S2: strong jamming is carried out to full leakage current signal and filters out operation, obtains arrester triple harmonic current；
S3: according to preset time starting point and full leakage current signal, total current phase angle is obtained, then to arrester triple-frequency harmonics electricity
Stream with total current phase angle carries out that current in resistance property is calculated；
It is wherein, described that arrester triple harmonic current and total current phase angle are carried out that current in resistance property is calculated, comprising:
According to the phase corresponding relationship and triple harmonic current and fundamental voltage between full leakage current signal and fundamental voltage
Between phase corresponding relationship, be calculated by the phase angle to total current phase angle, arrester triple harmonic current
Fundamental voltage phase angle；
Fourier decomposition is carried out to full leakage current signal according to fundamental voltage phase angle, obtains capacity current, then will leak entirely
Current signal subtracts capacity current and obtains current in resistance property.
2. resistive current of gapless metal-oxide lighting arrester inversion method according to claim 1, which is characterized in that step
Rapid S1 is specifically included:
Data acquisition is carried out to arrester by high-precision current transformer, preliminary current signal is obtained, preliminary electric current is believed
It number is converted and is amplified, obtain voltage signal；
It passes sequentially through bandpass filter, peak detection circuit, correcting circuit and DSP voltage signal is handled and leaked entirely
Current signal.
3. resistive current of gapless metal-oxide lighting arrester inversion method according to claim 1, which is characterized in that step
Rapid S2 is specifically included:
Criterion is maximized according to Signal Interference and Noise Ratio and establishes interference blocking matched filter, passes through interference blocking matched filter
The interference for carrying out different spectral feature to full leakage current signal filters out operation, and the full leakage current after obtaining interference filtering is believed
Number；
The full leakage current signal after interference filtering is carried out by Independent Component Analysis Algorithm and algorithm of principal component analysis capable and experienced
It disturbs and filters out operation, obtain the full leakage current signal after strong jamming filters out；
Full leakage current signal after being filtered out by Modern spectral estimation algorithm to strong jamming carries out harmonic wave extraction operation, is taken shelter from the thunder
Device triple harmonic current.
4. resistive current of gapless metal-oxide lighting arrester inversion method according to claim 1, which is characterized in that band
Bandpass filter is the multiple negative-feedback bandwidth-limited circuit of six ranks.
5. a kind of resistive current of gapless metal-oxide lighting arrester inverting device characterized by comprising
Acquisition unit obtains leaking electricity entirely for carrying out data acquisition to arrester by current transformer and bandpass filter
Flow signal；
Unit is filtered out, operation is filtered out for carrying out strong jamming to full leakage current signal, obtains arrester triple harmonic current；
Computing unit, for obtaining total current phase angle, then to arrester according to preset time starting point and full leakage current signal
Triple harmonic current and total current phase angle carry out that current in resistance property is calculated；
It is wherein, described that arrester triple harmonic current and total current phase angle are carried out that current in resistance property is calculated, comprising:
According to the phase corresponding relationship and triple harmonic current and fundamental voltage between full leakage current signal and fundamental voltage
Between phase corresponding relationship, be calculated by the phase angle to total current phase angle, arrester triple harmonic current
Fundamental voltage phase angle；
Fourier decomposition is carried out to full leakage current signal according to fundamental voltage phase angle, obtains capacity current, then will leak entirely
Current signal subtracts capacity current and obtains current in resistance property.
6. resistive current of gapless metal-oxide lighting arrester inverting device according to claim 5, which is characterized in that adopt
Collection unit specifically includes:
Subelement is acquired, for carrying out data acquisition to arrester by high-precision current transformer, obtains preliminary electric current letter
Number, preliminary current signal is converted and amplified, voltage signal is obtained；
Handle subelement, for pass sequentially through bandpass filter, peak detection circuit, correcting circuit and DSP to voltage signal into
Row processing obtains full leakage current signal.
7. resistive current of gapless metal-oxide lighting arrester inverting device according to claim 5, which is characterized in that filter
Except unit specifically includes:
First filters out subelement, establishes interference blocking matched filter for maximizing criterion according to Signal Interference and Noise Ratio, leads to
That crosses interference of the interference blocking matched filter to full leakage current signal progress different spectral feature filters out operation, is interfered
Full leakage current signal after filtering out；
Second filters out subelement, for passing through Independent Component Analysis Algorithm and algorithm of principal component analysis to letting out after interference filtering entirely
Leakage current signal carries out strong jamming and filters out operation, obtains the full leakage current signal after strong jamming filters out；
Subelement is extracted, harmonic wave is carried out for the full leakage current signal after filtering out by Modern spectral estimation algorithm to strong jamming and mentions
Extract operation obtains arrester triple harmonic current.
8. resistive current of gapless metal-oxide lighting arrester inverting device according to claim 5, which is characterized in that band
Bandpass filter is the multiple negative-feedback bandwidth-limited circuit of six ranks.
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| CN107561393A (en) * | 2017-10-16 | 2018-01-09 | 广东电网有限责任公司惠州供电局 | A kind of arrester early defect live testing system and method based on total current harmonic wave vector |
| CN108459228A (en) * | 2018-01-11 | 2018-08-28 | 东南大学 | A kind of 10KV metal oxide arresters line detection system for failure and method |
| CN108054835A (en) * | 2018-01-19 | 2018-05-18 | 宿迁电力设计院有限公司 | A kind of arrester intelligent cloud monitor system |
| CN108872747B (en) * | 2018-06-27 | 2023-07-04 | 南京信息工程大学 | Surge protector resistive current extraction device and method based on correlation coefficient |
| CN110940931A (en) * | 2019-09-18 | 2020-03-31 | 国网浙江省电力有限公司金华供电公司 | Lightning arrester leakage current online monitoring system and method |
| CN110470936B (en) * | 2019-09-25 | 2021-08-13 | 云南电网有限责任公司电力科学研究院 | Method and device for testing resistive current of line arrester |
| CN111025094A (en) * | 2019-11-19 | 2020-04-17 | 云南电网有限责任公司临沧供电局 | XLPE cable reliability evaluation method based on leakage current change coefficient |
| CN111157845B (en) * | 2020-01-07 | 2021-10-26 | 国网辽宁省电力有限公司朝阳供电公司 | Time domain inversion technology-based fault positioning method suitable for power distribution network |
| CN111505420B (en) * | 2020-04-29 | 2022-03-08 | 国网陕西省电力公司电力科学研究院 | Online monitoring and diagnosing method and system for state of line arrester |
| CN112649669B (en) * | 2020-12-21 | 2022-03-04 | 保定腾远电力科技有限公司 | Lightning arrester live-line detection method based on primary phase angle measurement |
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| JP2000275294A (en) * | 1999-03-25 | 2000-10-06 | Mitsubishi Electric Corp | Leakage current detecting device for zinc oxide lightning arrester |
| CN1892240B (en) * | 2005-07-08 | 2011-03-16 | 上海市电力公司 | On-line monitoring method for dissipative current value in leakage current of lightning protector |
| CN101533042A (en) * | 2009-04-10 | 2009-09-16 | 祝铭 | Method for monitoring resistive current of non-voltage reference quantity detection lightning arrester |
| CN102608392A (en) * | 2012-03-22 | 2012-07-25 | 上海市电力公司 | MOA (metal oxide arrester) resistive current detection system |
| CN106018998B (en) * | 2016-05-12 | 2018-12-14 | 广东电网有限责任公司电力科学研究院 | A kind of arrester test method and system |
| CN106324321A (en) * | 2016-08-23 | 2017-01-11 | 苏州亿科斯通电气有限公司 | Monitoring method and monitoring device for resistive current of zinc oxide lightning arrester |
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Effective date of registration: 20220822 Address after: 510080 water Donggang 8, Dongfeng East Road, Yuexiu District, Guangzhou, Guangdong. Patentee after: ELECTRIC POWER RESEARCH INSTITUTE OF GUANGDONG POWER GRID Co.,Ltd. Patentee after: Shanghai Dafan Precision Measurement Technology Co.,Ltd. Address before: 510080 water Donggang 8, Dongfeng East Road, Yuexiu District, Guangzhou, Guangdong. Patentee before: ELECTRIC POWER RESEARCH INSTITUTE OF GUANGDONG POWER GRID Co.,Ltd. Patentee before: SHANGHAI DAFAN ELECTRICAL EQUIPMENT Co.,Ltd. |