CN105182203B - A kind of power capacitor local discharge detection device and detection method - Google Patents
A kind of power capacitor local discharge detection device and detection method Download PDFInfo
- Publication number
- CN105182203B CN105182203B CN201510637963.7A CN201510637963A CN105182203B CN 105182203 B CN105182203 B CN 105182203B CN 201510637963 A CN201510637963 A CN 201510637963A CN 105182203 B CN105182203 B CN 105182203B
- Authority
- CN
- China
- Prior art keywords
- resistance
- capacitor
- amplifier
- power capacitor
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Amplifiers (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The invention belongs to power equipment Partial Discharge Detecting Technologies, it is specific to be related to a kind of power capacitor local discharge detection device and detection method, including piezoelectric sensor unit, detect amplifier circuit unit, filter unit, AD conversion unit and data control processing unit, the piezoelectric sensor unit is made of several piezoelectric transducers and is tightly attached to the ping discharge signal for picking up power capacitor part on power capacitor outer wall, after faint ping electric signal is amplified processing by the pre-amplifier unit, pass sequentially through filter unit, AD conversion unit, data control processing unit is handled.The ping that the issues when present invention crosses detection power capacitor shelf depreciation, to judge the type of power capacitor shelf depreciation, the present invention has not by electromagnetic interference, high sensitivity and the high advantage of noise.
Description
Technical field
This hair belongs to power equipment Partial Discharge Detecting Technology, is specifically related to a kind of power capacitor Partial Discharge Detection
Device and detection method.
Background technique
Power capacitor insulating inner is because the conditions such as process conditions, production environment, dielectric quality limit, unavoidably
Ground there are the inhomogeneities of defective (such as the air gap in solid dielectric, bubble) in liquid medium and field distribution, these
When the field strength of air gap bubble or local solid insulation on face reaches certain value or more, shelf depreciation, this electric discharge will occur
The penetrability breakdown that insulation will not generally be caused, will not form penetrability channel, but long-term shelf depreciation makes insulation immediately
Deterioration damage gradually expands, and can finally make entire insulation breakdown or edge flashing.The phenomenon of the failure of power capacitor includes leakage
Oil, bulge, shell sudden strain of a muscle irons, fuse blows, explosion etc..These failures there is a phenomenon where nearly all can with electric discharge: work as porcelain
When casing and shell leakage of oil.Inside pipe casing can make moist, insulation resistance reduces, pasta declines, member upper is easy dampness and sends out
Raw disruptive discharge.In the failure of all shunt capacitors, the ratio that bulge phenomenon accounts for is maximum.Coupling capacitor accident mostly occurs greatly
Among overcast and rainy filthy weather, accident phenomenon is that surface-discharge generation sudden strain of a muscle is ironed, and internal discharge accumulation may cause puncture short, melt
Disconnected device fusing or even explosion itself.
And the method for traditional detection power capacitor shelf depreciation is pulse current method, this method have one it is serious lack
Point, anti-electromagnetic interference capability is not strong, especially when detecting the shelf depreciation of the large capacities test products such as power capacitor, under sensitivity meeting
Drop, signal-to-noise ratio is very low or even signal is disturbed completely and falls into oblivion and can not measure.
Summary of the invention
It is an object of the present invention to solve the above problem of the prior art, provides one kind and overcome conventional electric power capacitor partial discharge
The low disadvantage low with noise of electric detection means sensitivity, the power capacitor local discharge detection device not limited by electromagnetic interference
And detection method, to achieve the goals above, The technical solution adopted by the invention is as follows:
A kind of power capacitor local discharge detection device, it is characterised in that: including piezoelectric sensor unit, detection amplification
Circuit unit, filter unit, AD conversion unit and data control processing unit, and the piezoelectric sensor unit is by several piezoelectricity
Sensor forms and is tightly attached to the ping discharge signal for picking up power capacitor part on power capacitor outer wall, the detection
After faint ping electric signal is amplified processing by amplifier circuit unit, filter unit, high speed analog-to-digital conversion are passed sequentially through
Unit, data control processing unit are handled.
Preferably, the piezoelectric transducer includes the vibrating diaphragm piece, the first piezo-electric crystal, the second piezoelectricity being arranged in housing chamber
Crystal, electrode, studdle and lead-out wire, the vibrating diaphragm piece are set to the bottom end in housing chamber, one end of the studdle
It is provided in the top in housing chamber, the center of vibrating diaphragm piece is provided with moveable first piezo-electric crystal, in the studdle
Protruding end end in and between the first piezo-electric crystal immovable second piezo-electric crystal and electrode are from top to bottom set, it is described
The inside that lead-out wire and electrode are connected and through the second piezo-electric crystal and studdle leads to the top of shell.
Preferably, the studdle is the structure of falling convex；It is small that the studdle structure occupies the space in housing chamber,
It is easy to fixed and connects, the sensitivity for shaking induction is higher.
Preferably, the broadband Application Range of the piezoelectric transducer is 0.03~1.5MHz.
Preferably, the detection amplifier circuit unit includes charge conversion circuit, suitable tune amplifying circuit, output amplification electricity
Road, overload indicating circuit and voltage-stabilized power supply circuit, the charge conversion circuit adjust amplifying circuit and output amplifier by suitable
Connection, the charge conversion circuit also connect with overload indicating circuit, the voltage-stabilized power supply circuit respectively with charge conversion circuit,
It is suitable to adjust amplifying circuit, output amplifier connection.
Preferably, the charge conversion circuit includes rail-to-rail FET input amplifier A1, capacitor C1, capacitor C5, capacitor
C4, resistance R1, resistance R2 and resistance R3, one end of the capacitor C5 are defeated with piezoelectric transducer after connecting with one end of capacitor C1
Outlet connection, the capacitor C4 and resistance R2 be connected in parallel after one end one end with the other end of capacitor C5, resistance R1 respectively
Connection, the capacitor C4 and resistance R2 be connected in parallel after the other end and rail-to-rail FET input amplifier A1 electrode input end
Connection, the output end of the rail-to-rail FET input amplifier A1 are connect with the other end of the capacitor C1 other end, resistance R1 respectively,
The negative input of the rail-to-rail FET input amplifier A1 is connect with one end of resistance R3, the other end of the resistance R3 with
Ground connection.
Preferably, the frequency range of the detection amplifier circuit unit is 0.03~1.5MHz, gain 50dB.
Preferably, the overload indicating circuit include the first comparison amplifier A2, the second comparison amplifier A3, resistance R4,
Resistance R5, resistance R6, resistance R7, the first partial pressure diode D1, the second partial pressure diode D2 and light emitting diode D3, indication signal
It is respectively connected to one end of one end of resistance R4, one end of resistance R5 and resistance R6, the anode of the first comparison amplifier A2 is defeated
It is connect again with the other end of resistance R5 after entering end and the connection of the second comparison amplifier A3 negative input, the resistance R4's is another
End is connect with the negative input of the first comparison amplifier A2, and the other end of the resistance R6 and the second comparison amplifier A3 are just
The connection of pole input terminal, the anode that the output end of the first comparison amplifier A2 divides diode D1 with first are connect, and second compares and put
The output end of big device A3 is connect with the anode of the second partial pressure diode D2, and described first divides the cathode of diode D1 and second point
It is connect again with one end of resistance R7 after the cathode connection of pressure diode D2, the other end of the resistance R7 is with light emitting diode D3's
Anode connection, the cathode of the light emitting diode D3 are connected to ground.
A kind of detection method of power capacitor shelf depreciation, characterized by the following steps:
(1) opening detecting device power supply, assembling, debugging detection device are at normal Standby state, then electric power is electric
Container is powered, and makes power capacitor shelf depreciation；
(2) it collected automatically by data control processing unit, store and process the shelf depreciation acoustical signal being detected；
(3) waveform diagram for taking out the acoustical signal handled well, judges capacitor according to waveform pulse figure duration
The position of shelf depreciation.
Preferably, have 15 or more continuous impulses in the timing chart, amplitude between -200mV~+200mV,
5 subpulses occur in each power frequency period, the rate of decay is very slow, and the duration between 60-80ms, judges that power capacitor is sent out
The position of raw electric discharge；
There are 4~5 continuous impulses in the timing chart, amplitude is between -400mV~+400mV, each power frequency week
2 subpulses occur in phase, quickly, the duration between 40-50ms, judges that power capacitor is put for decaying and the rate of climb
The position of electricity；
There is 1 individual pulse in the timing chart, what amplitude advise between -400mV~+400mV without
Rule only occurs once sometimes in a longer period of time, and quickly, the duration is very short for waveform attenuating, between 800 μ s~2ms,
Judge the position that power capacitor discharges.
In conclusion the present invention due to use above technical scheme, the invention has the following beneficial effects:
(1) bandpass filter in filter unit of the invention can eliminate most of noise in local discharge signal,
Improve the sensitivity of detection.
(2) present invention can apply to the shelf depreciations in laboratory and on-site test power capacitor, can capture test sample
The acoustical signal that shelf depreciation caused by product defect generates records complete waveform and can carry out wave character to the data of record
Extraction, spectrum analysis and three-dimensional spectrum.
(3) ping generated when present invention detection power capacitor shelf depreciation, can not be by electromagnetic interference
Limitation, overcomes the low disadvantage low with noise of conventional electric power capacitor partial discharge detection device sensitivity.
Detailed description of the invention
In order to illustrate more clearly of present example or technical solution in the prior art, to embodiment or will show below
There is in technical description required attached drawing do simply to introduce, it should be apparent that, the accompanying drawings in the following description is only the present invention
Some examples to those skilled in the art, can also be attached according to these under the premise of not paying creativeness
Figure obtains other attached drawings.
Fig. 1 is a kind of schematic diagram of power capacitor local discharge detection device of the invention.
Fig. 2 is the working principle diagram of detection amplifier circuit unit of the invention.
Fig. 3 is the structure chart of piezoelectric transducer of the present invention.
Fig. 4 is charge conversion circuit schematic diagram of the invention.
Fig. 5 is overload indicating circuit schematic diagram of the invention.
Fig. 6 is the catenation principle figure of the parallel overload indicating circuit of two-way of the invention.
Fig. 7 is suitable tune amplifying circuit schematic diagram of the invention.
Fig. 8 is output amplifier schematic diagram of the invention.
Fig. 9 is filter unit schematic illustration of the invention.
Figure 10 is a kind of overhaul flow chart of power capacitor detection method for local discharge of the invention.
In attached drawing, the first piezoelectric transducer of 1-, the second piezoelectric transducer of 2-, 3- third piezoelectric transducer, the 4th piezoelectricity of 4-
Sensor, the 5th piezoelectric transducer of 5-, the 6th piezoelectric transducer of 6-, 7- detect amplifier circuit unit, 8- filter unit, 9- modulus
Converting unit, 10- data control processing unit, 11- power capacitor, 12- coaxial cable for high frequency, 100- piezoelectric transducer list
Member, 200- vibrating diaphragm piece, the first piezo-electric crystal of 201-, the second piezo-electric crystal of 202-, 203- electrode, 204- shell, 205- support spiral shell
Bar, 206- lead-out wire.
Specific embodiment
Below in conjunction with the attached drawing in present example, technical solution in the embodiment of the present invention carries out clear, complete
Ground description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Based on hair
Embodiment in bright, every other implementation obtained by those of ordinary skill in the art without making creative efforts
Example, shall fall within the protection scope of the present invention.
As shown in Figure 1, a kind of power capacitor local discharge detection device, including piezoelectric sensor unit 100, detection are put
Big circuit unit 7, filter unit 8, AD conversion unit 9 and data control processing unit 10, the piezoelectric sensor unit 100
It is made of several piezoelectric transducers and is tightly attached to the ping electric discharge letter for picking up power capacitor part on power capacitor outer wall
Number, after faint ping electric signal is amplified processing by the detection amplifier circuit unit 7, pass sequentially through filter unit 8,
AD conversion unit 9, data control processing unit 10 are handled.In the present invention, as shown in Fig. 2, detection amplification electricity
Road unit (7) includes charge conversion circuit, suitable tune amplifying circuit, output amplifier, overload indicating circuit and regulated power supply electricity
Road, the charge conversion circuit adjust amplifying circuit to connect with output amplifier by suitable, the charge conversion circuit also with mistake
Indicating circuit connection is carried, the voltage-stabilized power supply circuit connects with charge conversion circuit, suitable tune amplifying circuit, output amplifier respectively
It connects.
In embodiments of the present invention, as shown in Figure 1, the piezoelectric sensor unit 100 is made of six piezoelectric transducers,
And it is tightly attached to the first piezoelectric transducer 1 of tested 11 housing front plate of power capacitor and is tightly attached to tested 11 shell of power capacitor
6th piezoelectric transducer 6 of rear wall, and it is tightly attached to the third piezoelectric transducer 3 and of tested 11 shell left wall of power capacitor
Five piezoelectric transducers 5, and it is tightly attached to the second piezoelectric transducer 2 and the 4th piezoelectricity biography of tested 11 shell right wall of power capacitor
Sensor 4.Six piezoelectric transducers are connected by conducting wire with detection amplifier circuit unit 7, and detection amplifier circuit unit 7 passes through high frequency
Coaxial cable 12 is connected with filter unit 8, and the acoustical signal that power capacitor shelf depreciation generates is by being tightly attached to outside power capacitor
Six piezoelectric transducers on wall pick up, and are translated into electric impulse signal, through detection amplifier circuit unit 7, filter unit 8,
The acoustic simulation signal that power capacitor shelf depreciation generates is converted digital signal by AD conversion unit 9, is controlled using data
Processing unit 10 is handled, is analyzed, being shown, being coordinated and managing entire detection device.It is mentioned from the electric discharge acoustical signal detected
Take and local discharge characteristic amount: waveform, amplitude-frequency characteristic, φ-q-n three-dimensional spectrum judge electric capacitor general ability according to these features
The position of portion's electric discharge.
In the present invention, as shown in figure 3, the piezoelectric transducer include be arranged in the intracavitary vibrating diaphragm piece 200 of shell 204,
First piezo-electric crystal 201, the second piezo-electric crystal 202, electrode 203, studdle 205 and lead-out wire 206, the vibrating diaphragm piece 200
It is set to the intracavitary bottom end of shell 204, one end of the studdle 205 is provided in the intracavitary top of shell 204, vibrating diaphragm piece
200 center is provided with moveable first piezo-electric crystal 201, presses in the protruding end of the studdle 205 and with first
Immovable second piezo-electric crystal 202 and electrode 203, the lead-out wire 206 and electricity are from top to bottom set between transistor 201
The inside that pole 203 is connected and through the second piezo-electric crystal 202 and studdle 205 leads to the top of shell 204.Movably
First piezo-electric crystal 201 experiences the vibrating diaphragm piece 200 of acoustic pressure, and the studdle 205 is the structure of falling convex, when sound wave is in vibrating diaphragm
When causing vibration on piece 200, studdle 205 is set to generate vertical tremor and generate displacement, at this time on the first piezo-electric crystal 201
Piezoelectric effect is generated, the change of the piezo-electric crystal both ends quantity of electric charge is caused, charge converges on electrode 203, so that acoustical signal be turned
It has changed high resistant charge signal Q into, electric signal is then exported to detection amplifier circuit unit 7, in order to determine electricity by lead-out wire 206
The frequency characteristic of acoustic emission signal caused by power capacitor different mode shelf depreciation, select broad frequency range be 0.03~
The piezoelectric transducer of 1.5MHz.
In embodiments of the present invention, as shown in figure 4, the charge conversion circuit include rail-to-rail FET input amplifier A1,
Capacitor C1, capacitor C5, capacitor C4, resistance R1, resistance R2 and one end of resistance R3, the capacitor C5 and one end of capacitor C1 connect
It connects, one end after the capacitor C4 is connected in parallel with resistance R2 is connect with one end of the other end of capacitor C5, resistance R1 respectively, institute
The other end after capacitor C4 is connected in parallel with resistance R2 is stated to connect with the electrode input end of rail-to-rail FET input amplifier, it is described
The output end of rail-to-rail FET input amplifier is connect with the other end of the capacitor C1 other end, resistance R1 respectively, described rail-to-rail
The negative input of FET input amplifier is connect with one end of resistance R3, and the other end of the resistance R3 is connected to ground, wherein
The positive power source terminal V+ of rail-to-rail FET input amplifier A1 is also attached with capacitor C2 and capacitor C3 respectively, realizes positive power source terminal
Filtering, also distinguish capacitor C6 in the negative power end V- of FET input amplifier A1 and connect with capacitor C7, realize the filter of negative power end
Wave.In embodiments of the present invention, the ultra-weak electronic signal that the detection amplifier circuit unit 7 collects piezoelectric sensor unit 100
Amplify processing, wherein the frequency range of the detection amplifier circuit unit 7 is 0.03~1.5MHz, gain 50dB；Pressure
The high resistant charge signal Q that electrical sensor units 100 export becomes low internal resistance voltage signal through charge conversion circuit, through rail-to-rail
FET input amplifier A1 amplifies output, and the rail-to-rail FET input amplifier A1 selects AD823 chip.In the present invention
It is also charge conversion circuit by voltage-stabilized power supply circuit, suitable tune amplifying circuit, output amplifier, overload indicating circuit provide conjunction
Suitable stable DC source.Electricity in order to reduce the influence interfered in small-signal transmission process, after enhanced processing is converted on the spot
Signal will be balanced with the signal of pre-amplifier unit 7 and match, as 0.03~1.5MHz of frequency band, gain 50dB.
Rail-to-rail FET input amplifier A1 enters nonlinear operating region in order to prevent, special designed overload instruction
Circuit, to monitor the state of charge conversion circuit work.In the present invention, as shown in figure 5, it is former for the first overload indicating circuit
Reason figure, selects single channel overload indicating circuit to carry out monitoring nonlinear operating region, and first overload indicating circuit includes first
Comparison amplifier A2, the second comparison amplifier A3, resistance R4, resistance R5, resistance R6, resistance R7, the first partial pressure diode D1, the
Two partial pressure diode D2 and light emitting diode D3, indication signal are respectively connected to one end of resistance R4, one end of resistance R5 and resistance
After one end of R6, the electrode input end of the first comparison amplifier A2 and the connection of the second comparison amplifier A3 negative input again
It is connect with the other end of resistance R5, the other end of the resistance R4 is connect with the negative input of the first comparison amplifier A2, institute
The other end for stating resistance R6 is connect with the electrode input end of the second comparison amplifier A3, the output end of the first comparison amplifier A2 with
The anode of the anode connection of first partial pressure diode D1, the output end of the second comparison amplifier A3 and the second partial pressure diode D2 connect
It connects, the cathode of the first partial pressure diode D1 connects with one end of resistance R7 again after connecting with the cathode of the second partial pressure diode D2
It connecing, the other end of the resistance R7 is connect with the anode of light emitting diode D3, and the cathode of the light emitting diode D3 is connected to ground,
The device type used in the present embodiment is double limit integrated computation comparators of LM392 as overload indicator.
As shown in fig. 6, being the parallel connection figure of the first overload indicating circuit and the second overload indicating circuit of the invention, this hair
In bright, the device type used the overload indicator parallel as two-way for double limit integrated computation comparators of LM392.Described
Two road overload indicating circuits include third comparison amplifier A21, the 4th comparison amplifier A31, resistance R41, resistance R51, resistance
R61, resistance R71, third partial pressure diode D11, the 4th partial pressure diode D21 and light emitting diode D31, indication signal connect respectively
Enter one end of one end of resistance R41, one end of resistance R51 and resistance R61, the anode input of the third comparison amplifier A21
It is connect again with the other end of resistance R51 after end and the connection of the 4th comparison amplifier A31 negative input, the resistance R41's is another
One end is connect with the negative input of third comparison amplifier A21, the other end and the 4th comparison amplifier of the resistance R61
The electrode input end of A31 connects, and the output end of third comparison amplifier A21 is connect with the anode of third partial pressure diode D11, the
The output end of four comparison amplifier A31 is connect with the anode of the second partial pressure diode D21, the third partial pressure diode D11's
Cathode is connect with one end of resistance R71 again after connecting with the cathode of the 4th partial pressure diode D21, the other end of the resistance R71
It is connect with the anode of light emitting diode D3, the cathode of the light emitting diode D3 is connected to ground.Indication signal U1, U2 is from steady
The reference voltage of piezoelectricity source circuit, and it is circuit voltage lower limit that U1 > U2, U1, which are circuit voltage upper limit value 10V, U2,
Value -10V.Be detected voltage Ui be charge conversion circuit output voltage, wherein the voltage range of indication signal Ui be+10V~-
10V is exported as Ui>U1 or Ui<U2 as high potential, is kept indicator light (light emitting diode D3) conducting shinny, is illustrated to input at this time
Signal exceeds the measurement range of charge amplifying circuit.
As shown in Figure 2 and Figure 6, rail-to-rail FET input amplifier A1 enters nonlinear operating region to the present invention in order to prevent
Except the state to monitor the work of charge conversion circuit.Amplifier enters the bigger range of nonlinear operation in order to prevent,
To prompt operator to select corresponding wider range of detection range.Under normal operating conditions, integrated computation comparator is in open loop shape
State works in saturation region, and indication signal U1, U2 is the reference voltage from voltage-stabilized power supply circuit, and U1 > U2, U1 are circuit works
Make upper voltage limit 10V, U2 is that circuit voltage lower limit value -10V, U1 pass through resistance R4 respectively, resistance R41 is input to first
Comparison amplifier A2 and third comparison amplifier A21, U2 pass through resistance R6 respectively, resistance 61 is input to the second comparison amplifier A3
With the 4th comparison amplifier A31.It is detected the voltage that voltage Ui1 is the output of charge conversion circuit, detected Ui2 is output amplification
The voltage of circuit end output, wherein the voltage range of indication signal Ui1, Ui2 is+10V~-10V, works as Ui1>U1 or Ui2<U2
When, it exports as high potential, keeps indicator light (light emitting diode D3 or light emitting diode D31) conducting shinny, illustrate that input is believed at this time
Number exceed charge amplifying circuit measurement range.
Such as Fig. 1 and as shown in Fig. 2, the height that the discharge signal of power capacitor 11 is exported by piezoelectric sensor unit 100
Resistance charge signal Q becomes low internal resistance voltage signal through charge conversion circuit again, then detects charge by overload indicating circuit and turns
The working condition of circuit is changed, and the low internal resistance voltage signal for simultaneously converting charge conversion circuit adjusts amplifying circuit by suitable,
As shown in fig. 7, inputting the negative input of operation comparator A4 by resistance R8, the resistance value size by adjusting resistance R9 makes
For output voltage within the scope of suitable, the suitable sensor for adjusting amplifying circuit to be adapted to different sensitivity accelerates each range
The test of degree, it is more accurate to test, and can improve measuring accuracy, and suitable tune amplifying circuit is the backend amplifier stage of charge amplifier, it
Effect other than voltage amplification, also have the effect of normalized concurrently, be by tested non electrical quantity (acceleration or pressure)
One timing has identical output, when going measurement with the sensor of different sensitivity to handle the figure sum number recorded
According to.The operational amplifier A4 selects reverse phase proportion operational amplifier to adjust amplifying circuit as suitable, the device type used for
AD829.The suitable adjustment signal input to output amplifying circuit for adjusting amplifying circuit, as shown in figure 8, i.e. adjustment signal passes through resistance
R11 is input to the negative input of operation comparator A5, and the voltage signal of the output end output of operation comparator A5 passes through respectively
12 input signal pretreatment unit 8 of coaxial cable for high frequency and overload indicating circuit, the electrode input end of operation comparator A5 pass through
Resistance R12 is connected to ground, and is adjusted potentiometer R13 and is connected between the negative input and output end of operation comparator A5, carries out
The gain coefficient for adjusting voltage, also connect with the anode of zener diode ZD1, two pole of pressure stabilizing in the output end of operation comparator A5
The cathode of pipe ZD1 is connect with the cathode of zener diode ZD2, and the anode of the zener diode ZD2 is connected to ground, by pressure stabilizing two
The amplitude limiter circuit of pole pipe ZD1 and zener diode ZD2 composition limits output voltage signal.As shown in figure 8, output amplification
Circuit is to realize that output voltage signal and charge signal Phase synchronization and second level are amplified, since charge converter unit itself is a product
The voltage-phase of point device circuit, input/output terminal can be reversed, keep the output of charge conversion circuit voltage and input charge at than
Example amplification, therefore, the problems such as resistance will appear Incomplete matching in circuit, circuit amplification factor is not very accurate, passes through tune
It saves the circuit and two-stage amplification and compensation calibration is carried out to voltage, adjusting potentiometer R13 can make output voltage at 0~10 times of gain
Between arbitrarily change, while by double limit 10V voltage-stabiliser tube diode ZD1 and zener diode ZD2 of output end, preventing output electric
Pressure exceeds the input voltage bound of subsequent incoming end.The device type that the operational amplifier A5 is selected is AD648B；It is described
The model of two zener diodes selects IN4740A.
In embodiments of the present invention, as shown in Figure 1, in the present invention, the data control processing unit 10 is by microcomputer
Calculation machine and display composition create application program by configuring installation Labview platform, collect electricity by Labview platform
The storage of container shelf depreciation acoustical signal waveform is handled in a computer, the collected electroacoustic signal of Labview with 0.03~
The broadband of 1.5MHz further filters the partial discharge of capacitor acoustical signal of storage, then shows the waveform of acoustical signal, width
Frequency characteristic, three-dimensional spectrum.In the present invention, as shown in figure 9, the filter unit 8 includes bandpass filter, voltage follower
A6, droop amplifier A7 and buffering driver A8 come extract and process each frequency range signal component and some low frequencies of removal or
The PERIODIC INTERFERENCE of high frequency, and the selectivity of frequency band is relatively more flexible, signal is further amplified after filtering and drives at processing
Reason, to meet the requirement of A/D sampling card input amplitude；In embodiments of the present invention, the bandpass filter is by six low pass filtereds
Wave device (FL1, FL2, FL3, FL4, FL5, FL6) and the combination of six high-pass filters (FH1, FH2, FH3, FH4, FH5, FH6) and
At being 4 rank Butterworth units, wherein a low-pass filter is connected in series with another high-pass filter, so two-by-two
The bandpass filter in six channels of composition is connected in parallel after series connection again, the upper cut-off frequency of six low-pass filters is set as
1.5MHz filters the signal that frequency is higher than 1.5MHz, and the lower-cut-off frequency of six low-pass filters is set as 0.03MHz, filters
Fall the signal that frequency is lower than 0.03MHz, lower and upper limit cutoff frequency can control processing unit 10 by data and be controlled
Fine tuning, and frequency error factor is convenient, the lower frequency limit of high-pass filter is 0.03MHz, allow the signal higher than this frequency to pass through, under
Limit cutoff frequency can be controlled processing unit 10 by data and carry out control fine tuning, and frequency error factor is convenient.Filtered signal warp
After voltage follower A6 impedance matching, the amplification for decaying and fixing multiple is carried out, by droop amplifier A7 to guarantee each
The consistency of frequency band under amplification factor.Signal is exported by buffering driver A8 again, make it have certain load driving capability with
Just it is directly connected to the A/D sampling card that input impedance is 50 Ω.In the present invention, the AD conversion unit 9 is same using six tunnels
The high-speed a/d capture card for walking work completes digital-to-analogue conversion, and sample frequency highest 10MHz converts digit as 12, and data length is
Every channel 512k data point.Sampled voltage synchronous with test voltage of the load on power capacitor (phase of two voltage, frequency
Rate must unanimously and power supply comes from same root bus), to obtain the phase information of electric discharge, display unit can real-time display discharge wave
Shape, the waveform of specified data and relevant statistical information.
In the present invention, as shown in Figure 10, a kind of overhaul flow chart of the detection method of power capacitor shelf depreciation, it is first
First device for opening power supply, assembling, debugging detection device are at normal Standby state, then power capacitor are powered, and make electricity
Power partial discharge of capacitor, by controlling the configuration installation creation Labview platform of processing unit 10, Labview platform in data
It can collect automatically, store and process the shelf depreciation acoustical signal being detected.Then recall what Labview platform had been handled well
The waveform diagram of acoustical signal, according to the feature of the waveform diagram of signal come the approximate location to judge partial discharge of capacitor.In electric power
In capacitor detection, the frequency that different parts electric discharge generates acoustical signal is different, the frequency for the acoustical signal that shelf depreciation generates at casing
Rate is higher than the frequency for the acoustical signal that electric discharge generates at insulating oil, and the frequency for the acoustical signal that shelf depreciation generates at insulating oil is higher than sky
The frequency for the acoustical signal that electric discharge machining in gas generates.Since sound frequency depends on the vibration frequency of sound producing body, sound is in propagation
Frequency will not change in the process.The intrinsic frequency of solid is greater than the intrinsic frequency of liquid, the intrinsic frequency of liquid under normal circumstances
Greater than the intrinsic frequency of air.
When electric discharge occur position in solids, the acoustical signal of generation is very big in the reflection coefficient of the surface of solids.In casing
The acoustical signal that place's electric discharge generates can constantly be reflected in internal surface of sleeve pipe, and acoustical signal is in first to rise shape of decaying afterwards, and can hold
Continuous longer time.Therefore, when the continuous impulse for having 15 or more in waveform diagram, amplitude is between -200mV~+200mV, often
5 subpulses occur in a power frequency period, the rate of decay is very slow, and the duration between 60-80ms, then can determine whether power capacitor
The position discharged is at casing；
When the position that electric discharge occurs is in insulating oil, shelf depreciation is more stable, and it is slow to decay, the duration
It is long.Therefore, when waveform pulse figure has 4~5 continuous impulses, amplitude is between -400mV~+400mV, each power frequency week
2 subpulses occur in phase, quickly, the duration between 40-50ms, then can determine whether that power capacitor is sent out for decaying and the rate of climb
The position of raw electric discharge is in insulating oil；
When electric discharge occurs in air, shelf depreciation is usually unstable, and duration is very short, and primary electric discharge occurs
Afterwards, the charge in air can be spread to surrounding rapidly, and enough energy productions can just be gathered after a period of time by needing puts next time
Electricity, while the attenuation ratio of discharge signal is very fast, therefore, when waveform pulse figure has 1 individual pulse, amplitude -400mV~+
What between 400mV, without rule, only occur once sometimes in a longer period of time, quickly, the duration is very for waveform attenuating
It is short, between 800 μ s~2ms, then it can determine whether position that power capacitor discharges in air.
The foregoing is merely the preferred embodiments of invention, are not intended to limit the invention, all in spirit of the invention
Within principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.
Claims (6)
1. a kind of power capacitor local discharge detection device, it is characterised in that: including piezoelectric sensor unit (100), detection
Amplifier circuit unit (7), filter unit (8), AD conversion unit (9) and data control processing unit (10), the piezoelectricity pass
Sensor cell (100), which is made of and is tightly attached to several piezoelectric transducers, picks up power capacitor part on power capacitor outer wall
Ping discharge signal, after faint ping electric signal is amplified processing by detection amplifier circuit unit (7), successively
It is handled by filter unit (8), AD conversion unit (9), data control processing unit (10)；The piezoelectric transducer
Broadband Application Range is 0.03~1.5MHz, and the piezoelectric transducer includes that the vibrating diaphragm piece intracavitary in shell (204) is arranged
(200), the first piezo-electric crystal (201), the second piezo-electric crystal (202), electrode (203), studdle (205) and lead-out wire
(206), the vibrating diaphragm piece (200) is set to the intracavitary bottom end of shell (204), and the studdle (205) is the knot of falling convex
Structure, one end of the studdle (205) are provided in the intracavitary top of shell (204), and the center of vibrating diaphragm piece (200) is provided with
Moveable first piezo-electric crystal (201), in the protruding end of the studdle (205) and with the first piezo-electric crystal (201)
Between immovable second piezo-electric crystal (202) and electrode (203), the lead-out wire (206) and electrode are from top to bottom set
(203) inside for being connected and through the second piezo-electric crystal (202) and studdle (205) leads to the top of shell (204)；Institute
The detection for stating power capacitor shelf depreciation includes the following steps:
(1) opening detecting device power supply, assembling, debugging detection device are at normal Standby state, then by power capacitor
It is powered, makes power capacitor shelf depreciation；
(2) it is collected automatically by data control processing unit (10), the shelf depreciation acoustical signal that storage and processing are detected；
(3) timing chart for taking out the acoustical signal handled well, judges capacitor according to timing chart duration
The position of shelf depreciation.
2. a kind of power capacitor local discharge detection device according to claim 1, it is characterised in that: the detection is put
Big circuit unit (7) includes charge conversion circuit, suitable tune amplifying circuit, output amplifier, overload indicating circuit and pressure stabilizing electricity
Source circuit, the charge conversion circuit adjust amplifying circuit to connect with output amplifier by suitable, and the charge conversion circuit is also
It is connect with overload indicating circuit, the voltage-stabilized power supply circuit is electric with charge conversion circuit, suitable tune amplifying circuit, output amplification respectively
Road connection.
3. a kind of power capacitor local discharge detection device according to claim 2, it is characterised in that: the charge turns
Changing circuit includes rail-to-rail FET input amplifier A1, capacitor C1, capacitor C5, capacitor C4, resistance R1, resistance R2 and resistance R3, institute
State capacitor C5 one end connect with one end of capacitor C1 after connect with the output end of piezoelectric transducer, the capacitor C4 and resistance R2
One end after being connected in parallel is connect with one end of the other end of capacitor C5, resistance R1 respectively, and the capacitor C4 is in parallel with resistance R2
The other end after connection is connect with the electrode input end of rail-to-rail FET input amplifier A1, the rail-to-rail FET input amplifier
The output end of A1 is connect with the other end of the capacitor C1 other end, resistance R1 respectively, and the rail-to-rail FET input amplifier A1's is negative
Pole input terminal is connect with one end of resistance R3, and the other end of the resistance R3 is connected to ground.
4. a kind of power capacitor local discharge detection device according to claim 1 or 2, it is characterised in that: the inspection
The frequency range for surveying amplifier circuit unit (7) is 0.03~1.5MHz, gain 50dB.
5. a kind of power capacitor local discharge detection device according to claim 2, it is characterised in that: the overload refers to
Show that circuit includes the first comparison amplifier A2, the second comparison amplifier A3, resistance R4, resistance R5, resistance R6, resistance R7, first
Diode D1, the second partial pressure diode D2 and light emitting diode D3 are divided, indication signal is respectively connected to one end of resistance R4, resistance
One end of R5 and one end of resistance R6, the electrode input end of the first comparison amplifier A2 and the second comparison amplifier A3 cathode
It is connect again with the other end of resistance R5 after input terminal connection, the cathode of the other end of the resistance R4 and the first comparison amplifier A2
Input terminal connection, the other end of the resistance R6 are connect with the electrode input end of the second comparison amplifier A3, and first compares amplification
The output end of device A2 is connect with the anode of the first partial pressure diode D1, the output end of the second comparison amplifier A3 and the second partial pressure two
The anode of pole pipe D2 connects, the cathode that the cathode of the first partial pressure diode D1 divides diode D2 with second connect after again with
One end of resistance R7 connects, and the other end of the resistance R7 is connect with the anode of light emitting diode D3, the light emitting diode D3
Cathode be connected to ground.
6. a kind of power capacitor local discharge detection device according to claim 1, it is characterised in that: the impulse wave
There are 15 or more continuous impulses in shape figure, between -200mV~+200mV 5 arteries and veins occur for amplitude in each power frequency period
Punching, the rate of decay is very slow, and the duration between 60-80ms, judges the position that power capacitor discharges；
There are 4~5 continuous impulses in the timing chart, amplitude is between -400mV~+400mV, in each power frequency period
2 subpulses occur, quickly, the duration between 40-50ms, judges what power capacitor discharged for decaying and the rate of climb
Position；
There is 1 individual pulse in the timing chart, amplitude is regular without what between -400mV~+400mV,
Only occurring once sometimes in longer time, quickly, the duration is very short for waveform attenuating, between 800 μ s~2ms, judgement
The position that power capacitor discharges.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510637963.7A CN105182203B (en) | 2015-09-30 | 2015-09-30 | A kind of power capacitor local discharge detection device and detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510637963.7A CN105182203B (en) | 2015-09-30 | 2015-09-30 | A kind of power capacitor local discharge detection device and detection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105182203A CN105182203A (en) | 2015-12-23 |
| CN105182203B true CN105182203B (en) | 2019-03-29 |
Family
ID=54904414
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510637963.7A Active CN105182203B (en) | 2015-09-30 | 2015-09-30 | A kind of power capacitor local discharge detection device and detection method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105182203B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113219309A (en) * | 2021-04-14 | 2021-08-06 | 深圳供电局有限公司 | Partial discharge detection device |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105676089B (en) * | 2016-02-29 | 2018-05-08 | 北京元六鸿远电子科技股份有限公司 | Multilayer ceramic capacitor non-destructive testing device and detection method |
| CN106855607A (en) * | 2017-01-04 | 2017-06-16 | 广西电网有限责任公司电力科学研究院 | A kind of packaged type Partial Discharge Sources analogue means |
| CN109270380B (en) * | 2018-10-17 | 2023-11-10 | 中铁第四勘察设计院集团有限公司 | Travelling wave measuring circuit of traction power supply system |
| CN110703076A (en) * | 2019-09-24 | 2020-01-17 | 河海大学 | GIS fault diagnosis method based on vibration signal frequency domain energy ratio |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1967176A (en) * | 2006-11-24 | 2007-05-23 | 华中科技大学 | Piezoelectric resonant diaphragm type sensor |
| KR20090050172A (en) * | 2007-11-15 | 2009-05-20 | 현대중공업 주식회사 | An apparatus for monitoring and diagnosing of a transformer |
| CN102353881A (en) * | 2011-07-12 | 2012-02-15 | 江苏镇安电力设备有限公司 | Online capacitor monitoring system based on partial discharge monitoring |
| CN202230176U (en) * | 2011-09-23 | 2012-05-23 | 上海市电力公司 | Remote directional online detection device used for power transmission and distribution line partial discharge detection |
| CN203216645U (en) * | 2012-12-03 | 2013-09-25 | 西安康鸿环保科技有限公司 | Multilayer piezoelectric ceramic pressure sensor |
| CN104061999A (en) * | 2014-07-08 | 2014-09-24 | 国家电网公司 | Partial discharge locating detection device of distribution transformer |
| CN104568238B (en) * | 2014-12-08 | 2018-02-23 | 太原航空仪表有限公司 | Piezoelectric excitation resonance membrane pressure sensor |
| CN205139298U (en) * | 2015-09-30 | 2016-04-06 | 广西电网有限责任公司电力科学研究院 | Power capacitor partial discharge detector device |
-
2015
- 2015-09-30 CN CN201510637963.7A patent/CN105182203B/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113219309A (en) * | 2021-04-14 | 2021-08-06 | 深圳供电局有限公司 | Partial discharge detection device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105182203A (en) | 2015-12-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105182203B (en) | A kind of power capacitor local discharge detection device and detection method | |
| CN105425106B (en) | A kind of Cable fault examination pilot system and its method of work | |
| CN108710074A (en) | A kind of partial discharge of switchgear detecting system based on Radio Transmission Technology | |
| CN103954890A (en) | DC partial discharge detection device and method for converter transformer | |
| CN106353657A (en) | High-voltage direct current cable partial discharge intelligent monitoring device and monitoring method | |
| CN101196547A (en) | Live testing apparatus for local discharge based on ultrasound assistance | |
| CN108989967B (en) | MIC shell cold joint detection device and detection method thereof | |
| CN102981110A (en) | Data measurement and storage system and method for achieving high frequency and ultra-high frequency partial discharge monitoring of transformer | |
| CN105717425A (en) | Supersonic online detection system of 1000kV GIS | |
| CN102547526A (en) | Real-time monitoring method and system of microphone working state | |
| CN103513158B (en) | Damped oscillatory wave lower cable local discharge detection device and method | |
| CN104849635A (en) | Partial discharge positioning system based on ultrasonic sensor array | |
| CN103713243B (en) | 10V inside switch cabinet discharging detection device based on electromagnetic antenna receiving array | |
| CN203037802U (en) | Data measuring storage system achieving transformer high-frequency and ultrahigh-frequency partial discharge monitoring | |
| CN108919069A (en) | A kind of method for detection of partial discharge of switch cabinet of Multi-source Information Fusion | |
| CN110736904A (en) | oiled paper insulation partial discharge monitoring device | |
| CN205139298U (en) | Power capacitor partial discharge detector device | |
| CN110426121A (en) | A kind of motor or engine abnormal noise detection device and method | |
| CN203572916U (en) | Intrusion type power distribution apparatus partial discharge on-line monitoring device | |
| CN108680843A (en) | A kind of method for detection of partial discharge of switch cabinet based on Radio Transmission Technology | |
| CN209446718U (en) | A kind of portable fault diagnosis device for 10KV network distribution transformer | |
| CN104879294B (en) | A kind of water pump transient signal analytical equipment and method | |
| CN207908626U (en) | A kind of simulation high frequency Partial discharge signal generating means | |
| CN217358737U (en) | Transformer space noise detection circuit | |
| CN115327327A (en) | Cable partial discharge detector based on ultrasonic technology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |