CN102480275A - Insulator full current amplification circuit - Google Patents
Insulator full current amplification circuit Download PDFInfo
- Publication number
- CN102480275A CN102480275A CN2010105555569A CN201010555556A CN102480275A CN 102480275 A CN102480275 A CN 102480275A CN 2010105555569 A CN2010105555569 A CN 2010105555569A CN 201010555556 A CN201010555556 A CN 201010555556A CN 102480275 A CN102480275 A CN 102480275A
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- China
- Prior art keywords
- insulator
- current
- amplifying circuit
- transport
- placing device
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- Testing Electric Properties And Detecting Electric Faults (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The invention provides an insulator full-current amplifying circuit which comprises an operational amplifier and a field-effect tube, wherein the positive phase input end of the operational amplifier is the input end of the insulator full-current amplifying circuit, the output end of the operational amplifier is the output end of the insulator full-current amplifying circuit, the grid electrode and the drain electrode of the field-effect tube are both connected with the output end of the operational amplifier, and the source electrode of the field-effect tube is connected to the negative phase input end of the operational amplifier. The insulator full current amplifying circuit provided by the embodiment of the invention realizes the constant-amplitude amplification of the insulator full current, thereby improving the detection precision of the insulator resistive current; meanwhile, high-voltage PT is not needed during voltage sampling, and the detection cost of the resistive current of the insulator is reduced.
Description
Technical field
The invention belongs to electronic technology field, relate in particular to a kind of insulator total current amplifying circuit.
Background technology
The pollution flashover of the insulator string of ultra-high-tension power transmission line is one of key factor that influences operation of power networks.Along with the aggravation of power system development and all kinds of pollutions, the pollution flashover accident is serious day by day, and it seriously hampers safe, stable, the economical operation of electric power system.Closely-related with the insulator degree is the size of its leakage current, and therefore the detection to insulator leakage current has very practical meaning.
The leakage full current of insulator has comprised capacitive leakage current (abbreviation capacity current) and two parts of resistive leakage current (abbreviation current in resistance property), and wherein, current in resistance property is the technical parameter that really reflects the insulator running status.And common must sample total current and voltage of the detection of current in resistance property again through calculating voltage and circuital angle, utilizes the trigonometric function relation to extrapolate the size of current in resistance property at last.
Though this detection method can obtain the size of current in resistance property, also exist following defective:
First; Because the leakage full current of insulator has only microampere order under the normal condition; And current in resistance property generally only accounts for circuital 10%-15%; Said method need pass through calculating voltage and circuital angle and utilize trigonometric function relation to calculate current in resistance property, and the current in resistance property value error that calculates through twice multiplication is bigger, thereby accuracy of detection is relatively poor, can't truly reflect the insulator work state;
The second, be low-voltage owing to need use the high pressure P T of sampled voltage to be about to high-voltage variable in the above-mentioned detection method, thereby it is higher to detect cost, can't promote.
Therefore need when detecting the sampled measurements leakage full current, amplify, improve the accuracy of detection of current in resistance property, and reduce and detect cost small total current.
Summary of the invention
The purpose of the embodiment of the invention is to provide a kind of insulator total current amplifying circuit, is intended to solve relatively poor, the cost problem of higher of precision in the existing insulator current in resistance property detection.
The embodiment of the invention is to realize like this; A kind of insulator total current amplifying circuit; Comprise a transport and placing device and FET Q, the normal phase input end of said transport and placing device is the leakage full current input of insulator, and the output of said transport and placing device is the output of insulator total current amplifying circuit; The grid of FET Q all links to each other with the output of transport and placing device with drain electrode, and the source electrode of FET Q is connected to the inverting input of transport and placing device.
Wherein, the model of said transport and placing device is TL062.
Wherein, the model of said FET is 3DJ8.
The insulator total current amplifying circuit that the embodiment of the invention provides amplifies the leakage full current of input through a transport and placing device; And the input through being located at said transport and placing device and the feedback effect of the FET between the output; Realize the circuital constant amplitude amplification of insulator, thereby improved insulator current in resistance property accuracy of detection; Simultaneously need not to carry out high pressure P T during sampled voltage, reduced the detection cost of insulator current in resistance property.
Description of drawings
Fig. 1 is the circuit diagram of the insulator total current amplifying circuit that provides of the embodiment of the invention.
Embodiment
In order to make the object of the invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
The insulator total current amplifying circuit that the embodiment of the invention provides can be applied to insulator current in resistance property monitoring with detect.Fig. 1 shows the circuit diagram of the insulator total current amplifying circuit that the embodiment of the invention provides; For the ease of explanation, only show the part relevant with the embodiment of the invention, details are as follows.
Insulator total current amplifying circuit comprises: transport and placing device A and FET Q; Wherein, The normal phase input end of transport and placing device A is the input of the leakage full current amplifying circuit of insulator; The output of transport and placing device A is the output of insulator total current amplifying circuit, and the grid of FET Q all links to each other with the output of transport and placing device A with drain electrode, and the source electrode of FET Q is connected to the inverting input of transport and placing device A.
For explanation the object of the invention further, to combine Fig. 1 that the operation principle of the insulator total current amplifying circuit that the embodiment of the invention provides is detailed following at present:
Behind the normal phase input end of insulator total current input transport and placing device A, because the amplification of transport and placing device A, the insulator total current is exaggerated the output output of back from transport and placing device A.Simultaneously, because the grid of FET Q all links to each other with the output of transport and placing device A with drain electrode, the source electrode of FET Q is connected to the inverting input of transport and placing device A, thereby forms the feedback circuit of a transport and placing device A.The model of transport and placing device A is TL062 in the present embodiment, and the model of said FET is 3DJ8.
The voltage difference V at the grid of FET Q and source electrode two ends
GS=V
OUT-V
IN
And the impedance R of FET Q
BBy V
GSDecision and in direct ratio, i.e. R
B=KV
GS,
Because R
BBe the feedback resistance of transport and placing device A, so the gain amplifier of transport and placing device A does
G＝fR
B＝fKV
GS＝fK(V
OUT-V
IN)；
Wherein, K, f are respectively FET Q and the intrinsic amplification coefficient of transport and placing device A, by device self the decision, K=0.05 in the present embodiment, f=40, G=fK (V
OUT-V
IN)=2 (V
OUT-V
IN).
Therefore, the difference V of the output input of insulator leakage full current of the present invention
OUT-V
INDetermined the amplifier gain amplifier, the leakage full current output of amplitude such as guaranteed.
Than prior art; The insulator total current amplifying circuit that the embodiment of the invention provides amplifies the leakage full current of input through transport and placing device; And the input through being located at said transport and placing device and the feedback effect of the FET between the output; Realize the circuital constant amplitude amplification of insulator, thereby improved insulator current in resistance property accuracy of detection; Simultaneously need not to carry out high pressure P T during sampled voltage, reduced the detection cost of insulator current in resistance property.
The above is merely preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of within spirit of the present invention and principle, being done, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.
Claims (3)
1. insulator total current amplifying circuit; It is characterized in that; Comprise a transport and placing device and FET, the normal phase input end of said transport and placing device is the input of insulator total current amplifying circuit, and the output of said transport and placing device is the output of insulator total current amplifying circuit; The grid of said FET all links to each other with the output of transport and placing device with drain electrode, and the source electrode of said FET is connected to the inverting input of transport and placing device.
2. insulator total current amplifying circuit as claimed in claim 1 is characterized in that the model of said transport and placing device is TL062.
3. insulator total current amplifying circuit as claimed in claim 1 is characterized in that the model of said FET is 3DJ8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105555569A CN102480275A (en) | 2010-11-23 | 2010-11-23 | Insulator full current amplification circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010105555569A CN102480275A (en) | 2010-11-23 | 2010-11-23 | Insulator full current amplification circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102480275A true CN102480275A (en) | 2012-05-30 |
Family
ID=46092786
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010105555569A Pending CN102480275A (en) | 2010-11-23 | 2010-11-23 | Insulator full current amplification circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102480275A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103364615A (en) * | 2013-07-17 | 2013-10-23 | 上海思盛电力控制技术有限公司 | Arrester leakage current monitor isolation sampling circuit |
| WO2019007168A1 (en) * | 2017-07-03 | 2019-01-10 | 京东方科技集团股份有限公司 | Current amplifying circuit and driving method therefor, and fingerprint detection device |
-
2010
- 2010-11-23 CN CN2010105555569A patent/CN102480275A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103364615A (en) * | 2013-07-17 | 2013-10-23 | 上海思盛电力控制技术有限公司 | Arrester leakage current monitor isolation sampling circuit |
| WO2019007168A1 (en) * | 2017-07-03 | 2019-01-10 | 京东方科技集团股份有限公司 | Current amplifying circuit and driving method therefor, and fingerprint detection device |
| US10979005B2 (en) | 2017-07-03 | 2021-04-13 | Boe Technology Group Co., Ltd. | Current amplification circuitry and driving method thereof, and fingerprint detection device |
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| C06 | Publication | ||
| PB01 | Publication | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120530 |