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CN103777126A - Transformer partial discharge ultrasonic sensor circuit structure - Google Patents

Transformer partial discharge ultrasonic sensor circuit structure Download PDF

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Publication number
CN103777126A
CN103777126A CN201310591086.5A CN201310591086A CN103777126A CN 103777126 A CN103777126 A CN 103777126A CN 201310591086 A CN201310591086 A CN 201310591086A CN 103777126 A CN103777126 A CN 103777126A
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CN
China
Prior art keywords
operational amplifier
amplifier
output terminal
partial discharge
transformer
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CN201310591086.5A
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Chinese (zh)
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CN103777126B (en
Inventor
高艳海
岳国良
刘宏亮
康勇
曹康
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State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Hebei Electric Power Co Ltd
State Grid Hebei Electric Power Co Ltd
Xingtai Power Supply Co of State Grid Hebei Electric Power Co Ltd
Original Assignee
State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Hebei Electric Power Co Ltd
State Grid Hebei Electric Power Co Ltd
Xingtai Power Supply Co of State Grid Hebei Electric Power Co Ltd
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Priority to CN201310591086.5A priority Critical patent/CN103777126B/en
Publication of CN103777126A publication Critical patent/CN103777126A/en
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  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
  • Testing Relating To Insulation (AREA)
  • Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)

Abstract

The invention relates to a transformer partial discharge ultrasonic sensor circuit structure, and belongs to the technical field of a power supply detection device. The technical scheme is as follows: an ultrasonic sensor (1), a filter (2), a first amplifier (3), a second amplifier (4), a third amplifier (5), an integrator (6) and a follower (7) are successively connected. A negative feedback circuit (8) has an input end mutually connected with the follower and an output end mutually connected with the second amplifier (4). The output end of a voltage bias circuit (9) is mutually connected with the second amplifier (4), the third amplifier (5), the integrator (6) and the negative feedback circuit respectively. The transformer partial discharge ultrasonic sensor circuit structure has the following advantages: the circuit principle is simple, only a small number of components are used, the amplification multiple can be adjusted, the output signal-to-noise ratio is high, the waveform output is good, the sensitivity is high, and ultrasonic signals generated by partial discharge of a transformer can be rapidly captured, therefore, the transformer partial discharge ultrasonic sensor circuit structure is especially suitable for partial discharge detection of the transformer.

Description

A kind of partial discharge of transformer sonac circuit structure
Technical field
The present invention relates to a kind of partial discharge of transformer sonac circuit structure, belong to power supply checkout equipment technical field.
Background technology
Along with the fast development of electric system, capacity and the electric pressure of transformer improve constantly in recent years, and operating safety problem also more and more comes into one's own.In the fault occurring at transformer, Insulation Problems accounts for very large proportion, therefore needs a kind of effective means to monitor the insulation status of transformer, guarantees the safety of transformer in service.No matter Partial Discharge Detection, as detecting the transformer insulated effective means of one, is etection theory or detection technique, has all obtained in recent years larger development, and in power plant and power station, has obtained actual application.Partial discharge of transformer ultrasonic method detects advantage strong with its antijamming capability and that be convenient to the aspects such as location has become the much-talked-about topic of domestic and international research at present.When shelf depreciation occurs, the pulse current that invariably accompanies, electromagnetic radiation and sound, light, heat produce some lower-molecular substances etc., the ultrasonic signal that shelf depreciation ultrasonic method produces for this process and growing up.The ultrasound wave that sonac produces partial discharge of transformer receives, and is translated into electric signal and processes, export.Traditional transformer shelf depreciation ultrasonic circuit signal to noise ratio (S/N ratio) is low, and signal when output wave form distortion sensitivity more and sensor is lower, therefore accurately locates the location comparison difficulty of partial discharge of transformer.
Summary of the invention
The object of the invention is to provide a kind of partial discharge of transformer sonac circuit structure, and by adopting three utmost point amplifiers, output signal-to-noise ratio is high, waveform output is good, highly sensitive, solves the problems referred to above that exist in background technology.
Technical scheme of the present invention is: a kind of partial discharge of transformer sonac circuit structure, comprise ultrasonic sensor, wave filter, first order amplifier, second level amplifier, third level amplifier, integrator, follower, negative-feedback circuit and voltage offset electric circuit, described ultrasonic sensor, wave filter, first order amplifier, second level amplifier, third level amplifier, integrator, follower connects successively, input end and the follower of negative-feedback circuit are connected to each other, output terminal and second level amplifier are connected to each other, the output terminal of voltage offset electric circuit respectively with second level amplifier, third level amplifier, integrator, negative-feedback circuit is connected to each other.
Described ultrasonic sensor is the piezoceramic transducer of 40-300KHz.
Described wave filter is the bandpass filter of 40-300KHz.
Described first order amplifier comprises triode one, electric capacity one and resistance one, and described triode one base stage and electric capacity one are connected to each other, and after collector and resistance one are connected to each other, receives power supply, and exports through electric capacity one.
Described second level amplifier, voltage offset electric circuit, third level amplifier, integrator, follower, negative-feedback circuit comprises operational amplifier one, operational amplifier two, operational amplifier three, operational amplifier four, operational amplifier five and operational amplifier six, operational amplifier one in-phase input end is connected to the tail end of first order amplifier, inverting input is connected to output terminal, and ground connection, form second level amplifier, the in-phase input end of operational amplifier two is connected to power supply, and ground connection, inverting input is connected to output terminal, form voltage offset electric circuit, and be connected to the input end of operational amplifier one homophase input pickup resistance, operational amplifier three in-phase input ends are connected to the output terminal of operational amplifier two, inverting input is connected to output terminal, form third level amplifier, the in-phase input end of operational amplifier four is connected to the output terminal of operational amplifier two, the output terminal that inverting input is connected to operational amplifier three forms integrator, operational amplifier five in-phase input ends are connected to the output terminal of operational amplifier four, inverting input is connected to output terminal, form follower, the in-phase input end of operational amplifier six is connected to the output terminal of operational amplifier two, inverting input is connected to the output terminal of operational amplifier five, and be connected to the inverting input of operational amplifier three, form negative-feedback circuit.
Also comprise operational amplifier seven, described operational amplifier seven in-phase input ends are connected to the output terminal of operational amplifier five, and inverting input is connected to output terminal.
The invention has the beneficial effects as follows: circuit theory is simple, components and parts consumption is few, and enlargement factor can regulate, and output signal-to-noise ratio is high, waveform output is good, highly sensitive, the ultrasonic signal can Quick Catch partial discharge of transformer producing, is particularly suitable for partial discharge of transformer and detects.
Accompanying drawing explanation
Fig. 1 is structured flowchart of the present invention;
Fig. 2 is circuit theory diagrams of the present invention;
In figure: ultrasonic sensor 1; Wave filter 2; First order amplifier 3; Second level amplifier 4; Third level amplifier 5; Integrator 6; Follower 7; Negative-feedback circuit 8; Voltage offset electric circuit 9; Operational amplifier one U1A; Operational amplifier two U1B; Operational amplifier three U2A; Operational amplifier four U2B; Operational amplifier five U2C; Operational amplifier six U2D; Operational amplifier seven U3B.
J-sonac; C-electric capacity; L-inductance; Q-triode; L-integrated chip; R-resistance; D-diode.
Embodiment
Below in conjunction with accompanying drawing, by embodiment, the invention will be further described.
A kind of partial discharge of transformer sonac circuit structure, comprise ultrasonic sensor 1, wave filter 2, first order amplifier 3, second level amplifier 4, third level amplifier 5, integrator 6, follower 7, negative-feedback circuit 8 and voltage offset electric circuit 9, described ultrasonic sensor 1, wave filter 2, first order amplifier 3, second level amplifier 4, third level amplifier 5, integrator 6, follower 7 connects successively, the input end of negative-feedback circuit 8 and follower 7 are connected to each other, output terminal and second level amplifier 4 are connected to each other, the output terminal of voltage offset electric circuit 9 respectively with second level amplifier 4, third level amplifier 5, integrator 6, negative-feedback circuit 8 is connected to each other.
The piezoceramic transducer that described ultrasonic sensor 1 is 40-300KHz.
The bandpass filter that described wave filter 2 is 40-300KHz.
Described first order amplifier 3 comprises triode one, electric capacity one and resistance one, and described triode one base stage and electric capacity one are connected to each other, and after collector and resistance one are connected to each other, receives power supply, and exports through electric capacity one.
Described second level amplifier 4, voltage offset electric circuit 9, third level amplifier 5, integrator 6, follower 7, negative-feedback circuit 8 comprises operational amplifier one U1A, operational amplifier two U1B, operational amplifier three U2A, operational amplifier four U2B, operational amplifier five U2C and operational amplifier six U2D, operational amplifier one U1A in-phase input end is connected to the tail end of first order amplifier 3, inverting input is connected to output terminal, and ground connection, form second level amplifier 4, the in-phase input end of operational amplifier two U1B is connected to power supply, and ground connection, inverting input is connected to output terminal, form voltage offset electric circuit 9, and be connected to the input end of operational amplifier one U1A in-phase input end resistance, operational amplifier three U2A in-phase input ends are connected to the output terminal of operational amplifier two U1B, inverting input is connected to output terminal, form third level amplifier 5, the in-phase input end of operational amplifier four U2B is connected to the output terminal of operational amplifier two U1B, the output terminal that inverting input is connected to operational amplifier three U2A forms integrator 6, operational amplifier five U2C in-phase input ends are connected to the output terminal of operational amplifier four U2B, inverting input is connected to output terminal, form follower 7, the in-phase input end of operational amplifier six U2D is connected to the output terminal of operational amplifier two U1B, inverting input is connected to the output terminal of operational amplifier five U2C, and be connected to the inverting input of operational amplifier three U2A, form negative-feedback circuit 8.
Also comprise operational amplifier seven U3B, described operational amplifier seven U3B in-phase input ends are connected to the output terminal of operational amplifier five U2C, and inverting input is connected to output terminal.
Partial discharge of transformer sonac circuit, its ultrasonic sensor adopts 40-300KHz piezoceramic transducer, because the acoustic impedance of piezoelectric ceramics and air differs too large (being about 4-5 the order of magnitude), need increase impedance matching layer for improving receiving efficiency; Its wave filter is the bandpass filter of 40-300KHz, reduces the interference of outside noise signal to useful signal, improves signal to noise ratio (S/N ratio); Its amplifying circuit adopts the amplifying circuit of low-noise low-power consumption, and it is adjustable to gain.
Pressure drop in the situation that there is no signal input between base stage and the emitter of triode Q1 is 0, and not conducting of triode does not have AC signal effectively in circuit, the output of J4 output terminal no signal.
Receive after ultrasonic signal at J1, between the base stage of first order amplifier triode Q1 and emitter, voltage is greater than 0.7V, and triode conducting, amplifies signal, by regulating the resistance size of R3, can change its enlargement factor.Every directly, provided the voltage of 1/2VCC1 through C4 by voltage offset electric circuit operational amplifier two U1B, second level amplifier operational amplifier one U1A amplifies; Amplify through third level amplifier operational amplifier three U2A again; Integrator operational amplifier four U2B act as signal lag anti-phase input 90 are spent; Through follower operational amplifier five U2C; By negative-feedback circuit operational amplifier six U2D, signal is turned back to the inverting input of second level amplifier, and phase lag signal 180 is spent; Finally by crossing the seven U3B outputs of follower operational amplifier, act as and reduce output resistance; U4 place is the feed circuit of circuit.
The model of each integrated circuit is that triode Q1 is BC550C; U1, U3 are TL062; U2 is TL064; U4 is L78L09ACZ.

Claims (6)

1. a partial discharge of transformer sonac circuit structure, it is characterized in that: comprise ultrasonic sensor (1), wave filter (2), first order amplifier (3), second level amplifier (4), third level amplifier (5), integrator (6), follower (7), negative-feedback circuit (8) and voltage offset electric circuit (9), described ultrasonic sensor (1), wave filter (2), first order amplifier (3), second level amplifier (4), third level amplifier (5), integrator (6), follower (7) connects successively, the input end of negative-feedback circuit (8) and follower (7) are connected to each other, output terminal and second level amplifier (4) are connected to each other, the output terminal of voltage offset electric circuit (9) respectively with second level amplifier (4), third level amplifier (5), integrator (6), negative-feedback circuit (8) is connected to each other.
2. a kind of partial discharge of transformer sonac circuit structure according to claim 1, is characterized in that: the piezoceramic transducer that described ultrasonic sensor (1) is 40-300KHz.
3. a kind of partial discharge of transformer sonac circuit structure according to claim 1, is characterized in that: the bandpass filter that described wave filter (2) is 40-300KHz.
4. a kind of partial discharge of transformer sonac circuit structure according to claim 1, it is characterized in that: described first order amplifier (3) comprises triode one, electric capacity one and resistance one, described triode one base stage and electric capacity one are connected to each other, after collector and resistance one are connected to each other, receive power supply, and export through electric capacity one.
5. a kind of partial discharge of transformer sonac circuit structure according to claim 1, it is characterized in that: described second level amplifier (4), voltage offset electric circuit (9), third level amplifier (5), integrator (6), follower (7), negative-feedback circuit (8) comprises operational amplifier one (U1A), operational amplifier two (U1B), operational amplifier three (U2A), operational amplifier four (U2B), operational amplifier five (U2C) and operational amplifier six (U2D), operational amplifier one (U1A) in-phase input end is connected to the tail end of first order amplifier (3), inverting input is connected to output terminal, and ground connection, form second level amplifier (4), the in-phase input end of operational amplifier two (U1B) is connected to power supply, and ground connection, inverting input is connected to output terminal, form voltage offset electric circuit (9), and be connected to the input end of operational amplifier one (U1A) in-phase input end resistance, operational amplifier three (U2A) in-phase input end is connected to the output terminal of operational amplifier two (U1B), inverting input is connected to output terminal, form third level amplifier (5), the in-phase input end of operational amplifier four (U2B) is connected to the output terminal of operational amplifier two (U1B), the output terminal that inverting input is connected to operational amplifier three (U2A) forms integrator (6), operational amplifier five (U2C) in-phase input end is connected to the output terminal of operational amplifier four (U2B), inverting input is connected to output terminal, form follower (7), the in-phase input end of operational amplifier six (U2D) is connected to the output terminal of operational amplifier two (U1B), inverting input is connected to the output terminal of operational amplifier five (U2C), and be connected to the inverting input of operational amplifier three (U2A), form negative-feedback circuit (8).
6. a kind of partial discharge of transformer sonac circuit structure according to claim 3, it is characterized in that: also comprise operational amplifier seven (U3B), described operational amplifier seven (U3B) in-phase input end is connected to the output terminal of operational amplifier five (U2C), and inverting input is connected to output terminal.
CN201310591086.5A 2013-11-22 2013-11-22 A kind of partial discharge of transformer sonac circuit structure Active CN103777126B (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106197430A (en) * 2016-07-29 2016-12-07 成都蛋壳众创科技有限公司 A kind of high-performance based on cloud computing navigation processing system
CN110763959A (en) * 2019-09-24 2020-02-07 武汉汉源既济电力有限公司 High-voltage switch cabinet partial discharge detection circuit and detection method thereof

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106197430A (en) * 2016-07-29 2016-12-07 成都蛋壳众创科技有限公司 A kind of high-performance based on cloud computing navigation processing system
CN106197430B (en) * 2016-07-29 2019-03-22 成都蛋壳众创科技有限公司 A kind of high-performance navigation processing system based on cloud computing
CN110763959A (en) * 2019-09-24 2020-02-07 武汉汉源既济电力有限公司 High-voltage switch cabinet partial discharge detection circuit and detection method thereof
CN110763959B (en) * 2019-09-24 2022-02-22 武汉汉源既济电力有限公司 High-voltage switch cabinet partial discharge detection method

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