CN106124951A - Time-frequency mix insulation diagnostic system based on polarization depolarization current method - Google Patents
Time-frequency mix insulation diagnostic system based on polarization depolarization current method Download PDFInfo
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- CN106124951A CN106124951A CN201610807842.7A CN201610807842A CN106124951A CN 106124951 A CN106124951 A CN 106124951A CN 201610807842 A CN201610807842 A CN 201610807842A CN 106124951 A CN106124951 A CN 106124951A
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- 238000009413 insulation Methods 0.000 title claims abstract description 30
- 230000002999 depolarising Effects 0.000 title claims abstract description 11
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- 230000001808 coupling Effects 0.000 claims abstract description 5
- 238000010168 coupling process Methods 0.000 claims abstract description 5
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- 230000003287 optical Effects 0.000 claims abstract description 5
- 238000001514 detection method Methods 0.000 claims description 15
- 230000000875 corresponding Effects 0.000 claims description 4
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- 238000007689 inspection Methods 0.000 description 1
- 238000011068 load Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
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- 238000010183 spectrum analysis Methods 0.000 description 1
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
Abstract
Time-frequency mix insulation diagnostic system based on polarization depolarization current method, including some covering devices, described device includes power supply, Insulation test electrode case, controls switch, micro-current sensing circuit, dsp detecting system and host computer processing system.Described power supply can provide power supply to needing power pack in voltage amplifier circuit and other circuit.The device being powered described device is made up of a series of circuit, forms including current rectifying and wave filtering circuit, optical coupling isolation circuit and amplifying circuit, and described Insulation test electrode case to ensure that shielding is good, without extraneous harmonic wave interference.The time-frequency Hybrid approaches of diagnosis of polarization depolarization current method is by the very effective method of insulation diagnosis, and described system can detect the state of insulation of surveyed material accurately.
Description
Technical field
The association areas such as the insulation diagnosis of insulative dielectric spectrum detection association area and dielectric.
Background technology
The time domain measurement method of dielectric spectra insulation diagnosis technology includes polarizing depolarization current method and recovering voltage method two kinds, and
Common impedance analysis measuring technology.These detection methods can accurate acquisition transformer oil paper insulation, motor epoxy cloud
Water content etc. and aging closely-related important information in Electric Power Equipment Insulation degree of aging, the insulating papers such as female insulation.Work as insulation
When degree of aging is deepened, transformator is susceptible to fault, and the fault rate of power system increases.The transformer insulated shape of effective assessment
State can improve equipment dependability, safety and grid supply quality.Both at home and abroad about transformator ageing state and fault diagnosis
Method can be largely classified into two classes: be on the one hand the detection of transformer solid insulation material electrical property；On the other hand it is transformator
The chemical detection of oil.The electrically method of detection mainly polarization depolarization current detection method and Spectral Analysis Method.
Summary of the invention
Patent of the present invention compensate for the deficiencies in the prior art, it is provided that time-frequency mixing based on polarization depolarization current method is absolutely
Edge diagnostic system, described device is by power-supply system, Insulation test electrode case, control switch, micro-current sensing circuit, dsp inspection
Examining system, host computer processing system form.Described power-supply system by current rectifying and wave filtering circuit, amplifying circuit, DC source, optocoupler every
Form from circuit；When carrying out power supply and selecting, can select battery is that circuit is powered, and selects the advantage that battery is powered
It is not have harmonic wave to disturb；Actually detected carry out circuit build time, use battery power can price comparison expensive, therefore described
Circuit typically uses 220V general distribution power supply to be powered；The harmonic ratio powered due to described common power is more, if humorous
Ripple can be amplified accordingly by amplifying circuit, and component can be caused damage by this；Described general distribution power supply first passes through
Transformator carries out reducing voltage, then by current rectifying and wave filtering circuit, makes described circuit voltage be dropped to circuit by 220V acceptable
Low-voltage；Described concrete numerical value describes in using method in detail；Described DC circuit provides corresponding straight for related device
Stream power supply, described optical coupling isolation circuit is possible to prevent harmonic wave to disturb, and has been shielding interference effect, and the most described photoelectric coupled circuit is to electricity
The requirement ratio of pressure is relatively low, the connection made above of amplifying circuit to be placed on.
Described Insulation monitoring is the three-electrode system of Insulation test in trying out electrode case, and casing has good screen simultaneously
Covering electromagnetic wave effect, this detection belongs to micro-current detecting, and described device must have good shielding electromagnetic interference effect, simultaneously
There is good ground connection.Described control on-off action and micro-current sensing circuit effect and effect are carried out by hereinafter using method
Narration in detail.
Described dsp detecting system and host computer processing system are collected collected by micro-current sensing circuit by detecting system
Signal, carries out corresponding process operation, is delivered to host computer and carries out later stage process, present figure, finally provide relevant number
According to analysis, carry out the insulation diagnosis of material.
Being at novelty of the present invention: described system is easy to build at laboratory, described circuit theory is the most easily electricity
Power personnel understand, overcome conventional Insulation monitoring and require time for long, the feature that equipment is big；When carrying out insulation diagnosis, use and be situated between
Electrography detection is the most popular detection method, and described method is time-frequency detection method in dielectric spectra detection technique, can
To be greatly shortened the required detection time, improve accuracy of detection.
Accompanying drawing explanation
Fig. 1 is the structural representation of the present invention.
Fig. 2 is power-supply system built-in system figure.
Fig. 3 is current rectifying and wave filtering circuit structure principle chart.
Fig. 4 is optical coupling isolation circuit structure principle chart.
Fig. 5 is amplification circuit structure schematic diagram.
Fig. 6 is micro-current sensing circuit schematic diagram.
Fig. 7 be A2 positive and negative supply voltage figure.
Fig. 8 is that depolarization current is measured and match value figure.
Fig. 9 is depolarization current curve matching and measured value figure.
In figure: 1, power-supply system.2, switch (1) is controlled.3, Insulation test electrode case.4, switch (2) is controlled.5, micro-electricity
Flow measurement circuitry.6, dsp detecting system.7, host computer processing system.
Detailed description of the invention
Application instantiation carries out general remark to the present invention below, and the occupation mode of the present invention is a kind of, also has it
His form.
Embodiment: described system is provided electric energy by power supply 1, accesses common electricity consumption alternating current 220V and passes through transformer pressure-reducing, then
By current rectifying and wave filtering circuit, voltage is reduced to 5V；Consider the independence of described every one-level element circuit, it is therefore necessary to design every
From the isolation of circuit input signal Yu output signal, and the electrical isolation of element circuit at different levels, also it is avoided that circuit shakes simultaneously
Swing and feed back to front end.Accessing optical coupling isolation circuit, described circuit is isolation circuit based on high precision photoelectric bonder HCNR201
Circuit design input signal amplitude range is 1mV ~ 10V.By changing R in Fig. 42Resistance value can realize gain-adjusted, nothing
Additional bias is needed to regulate circuit.In order to improve the output accuracy of circuit, the input of Amplifier OP07 should pass through with rear class output
Kelvin connects.What Kelvin connected is the method for attachment of a kind of analog quantity teletransmission, and feedback line is not the outfan from amplifier
Introduce, but introduced by load end.Kelvin's connection avoids the error that line transmission causes.The isolation electricity designed herein
The amplitude that road can realize output signal is identical with input, and phase offset is stablized constant in certain frequency range.
Described amplifying circuit circuit is as it is shown in figure 5, described amplifying circuit is possible not only to reach the preferable linearity and permissible
Output random waveform voltage.Each unit module output voltage is up to 400 Vpp, higher by exporting after multiple-unit cascade
Voltage magnitude, the output upper limit is only dependent upon the isolation voltage of prime light-coupled isolation voltage and supply transformer.This circuit is permissible
Input free voltage waveshape signal, input voltage signal is the output of light-coupled isolation rear end.Circuit is by six high pressure and high output electricity
The OPA454 operational amplifier composition of stream.OPA454 gain stabilization and slew rate are up to 13V/, and gain bandwidth product reaches 2.5MHz.Put
Big circuit has wider supply district, can be ± 5V ~ ± 50V bipolarity is powered or 10V ~ 100V unipolarity is powered.By A1、A2、
A3Three operational amplifiers constitute a series voltage negtive backword circuit with 20 times of amplifications, operational amplifier A 1 and A3
Constitute two voltage followers and be responsible for A2Amplifier provides power supply.The supply voltage of tri-operational amplifiers of A1 ~ A3 is
100V.V in Fig. 501And V02It is respectively A2Positive and negative supply voltage.When input voltage signal changes, the V of positive polarity01And negative pole
The V of property02Also followed by change.But no matter how input signal changes, V01And V02The absolute value of difference remain at 100V
Within, by the change power supply measure of wide scope followability, thus ensure that amplifying circuit can export higher voltage magnitude.
In like manner, circuit right part is by A4、A5、A6Three operational amplifiers constitute a voltage parallel with 20 times of amplifications and bear
Feedback circuit.The limit according to OPA454 runs maximum parameter VS=(V+)-(V-)=120V, in order to make full use of amplifier thus
Realizing optimum to amplify, the supply voltage of circuit design is (V+)-(V-)=100V, and directly adds 100V power supply and cannot realize finally
The output of peak-to-peak value 400V.Therefore, amplifier circuit design being middle amplification by upper and lower two amplifiers equally provides electricity
Source, thus expand voltage output range.Upper and lower two amplifiers in left side connect 100V power supply, it is achieved follow prime output voltage, and
And raise 50V；Right side realizes following prime output voltage, and reduces 50V.And the difference of amplifier output waveform is up and down
Constant 100V, thus provide power supply for middle amplifier.Opposite polarity after signal being amplified due to the left and right sides, thus two-way
Amplification is stackable.Every element circuit achieves 40 times of amplifications (400Vpp) to input.
Described Insulation test electrode case, is Insulation test three-electrode system in electrode case, and wherein portable protective gaps is
2mm, measures electrode diameter 50mm.Owing to the detection of tested dielectric belongs to micro-current range, easily affected by external interference,
Particularly to be generally PA level the least the depolarization current later stage, therefore to sample and to measure lead-in wire and take well to shield be test
Crucial.In test, the shielding shell of electrode case and micro current circuit wants reliable ground.Current signal passes through micro-testing current
After circuit, original micro-current magnification it is voltage signal, by output voltage signal by dsp system acquisition data, is transferred to
The display of image is carried out on host computer.
Described micro-current sensing circuit, micro-current sensing circuit is made up of two parts: prime I-V converter amplifier circuit with after
Level amplifying circuit.When electric current is measured, tested current signal should be converted to voltage signal by amplifier and resistance, right
In dielectric spectra waving map high due to Medium impedence, it is desirable to the operational amplifier of selection should have high input impedance and common mode presses down
System ratio；The design select ultralow bias current operational amplifier OPA129, input use static level isolation field effect transistor skill
Art, maximum bias electric current is ± 250fA, maximum offset voltage ± 5mV, common mode rejection ratio 120dB.In the measurements, due to quilt
The excursion measured is relatively big, therefore amplifying circuit is carried out range switching when measuring.The method of range switching is exactly right
R in T type network1Switched over by switch, respectively by resistance R18 between 100G Ω ~ 10k Ω are switched to switch
Individual gear, wherein the resistance R of more than 1G1Using RI1 type vacuum glass glaze film high resistance measurement, precision is ± 5%.Rear class is put
Big circuit here plays certain amplification and buffer action, and the amplifier in circuit uses AD620, and its advantage is low in energy consumption, essence
Degree height, can be by regulation resistance RKValue realize regulate post-amplifier amplification K, according to AD620 data book,
K meets relational expression:
Formula is expressed in the input and output of amplifying circuit:
Described control switchs (1), when switch contact mains side circuit, controls to switch (2) simultaneously and connects measurement circuitry, and expression starts
Detect, circuit connected dsp detecting system, simultaneously UNICOM's host computer processing system, processing through dsp system,
Related data is imported after host computer is analyzed, relevant waveform can be observed on host computer, pass through model database
Compare, it is judged that whether insulation damages.Discharge circuit connected by the described switch (1) that controls, and controls to switch (2) simultaneously and connects short circuit
Circuit, carries out discharge operation, needs Insulation test electrode case is carried out discharge operation after having carried out once test.The most anti-
Multiple operation, carries out the insulation diagnosis of material.
The amplified A/D translation interface sending DSP to of described micro-electric current, micro-current signal is turned by the A/D module of DSP
Be changed to digital signal, by DSP this digital signal carried out digital filtering, time/frequency-domain analysis etc. processes, and result led to
Cross SCI interface and send host computer to.Host computer uses LABVIEW to write parsing and interface program, carries out the result of DSP
Resolving and show in the form of images, supply experimenter is analyzed research to experimental result.The present invention is not had simultaneously
In place of describing, it it is all the content that in this area, experimenter both knows about.By described above, the user of this area is known
The preferable part of this invention of road；Should carry out stating, in the case of the core without departing from invention, any type of ratio
Easier deformation and amendment are all within protection scope of the present invention.
Claims (1)
1. time-frequency mix insulation diagnostic system based on polarization depolarization current method is characterized in that, described structure includes power supply system
System, control switch (1), Insulation test electrode case, control switch (2), micro current circuit, dsp detecting system, host computer
Processing system；Described power-supply system comprises current rectifying and wave filtering circuit, amplifying circuit, DC source, optical coupling isolation circuit；Described direct current
Power supply needs the device providing DC source to provide the input of corresponding voltage for each, and wherein said dsp detecting system is also required to
DC source provides corresponding voltage；Described Insulation test electrode case need to shield well, and the electric current of detection is the most small, externally
Boundary's interference sensitivity is high；The most described Insulation test electrode case must have good grounding measures, it is ensured that casing and the earth
This good conductor UNICOM, ensures that electrostatic produced by casing can quickly introduce in the earth system simultaneously.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610807842.7A CN106124951A (en) | 2016-09-07 | 2016-09-07 | Time-frequency mix insulation diagnostic system based on polarization depolarization current method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610807842.7A CN106124951A (en) | 2016-09-07 | 2016-09-07 | Time-frequency mix insulation diagnostic system based on polarization depolarization current method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106124951A true CN106124951A (en) | 2016-11-16 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610807842.7A Withdrawn CN106124951A (en) | 2016-09-07 | 2016-09-07 | Time-frequency mix insulation diagnostic system based on polarization depolarization current method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110794273A (en) * | 2019-11-19 | 2020-02-14 | 哈尔滨理工大学 | Potential time domain spectrum testing system with high-voltage driving protection electrode |
-
2016
- 2016-09-07 CN CN201610807842.7A patent/CN106124951A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110794273A (en) * | 2019-11-19 | 2020-02-14 | 哈尔滨理工大学 | Potential time domain spectrum testing system with high-voltage driving protection electrode |
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Application publication date: 20161116 |
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