CN204154778U - A kind of active faint power current inductive coil - Google Patents
A kind of active faint power current inductive coil Download PDFInfo
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- CN204154778U CN204154778U CN201420638595.9U CN201420638595U CN204154778U CN 204154778 U CN204154778 U CN 204154778U CN 201420638595 U CN201420638595 U CN 201420638595U CN 204154778 U CN204154778 U CN 204154778U
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- 230000001939 inductive effect Effects 0.000 title abstract 4
- 238000005070 sampling Methods 0.000 claims abstract description 28
- 230000006698 induction Effects 0.000 claims description 47
- 239000003990 capacitor Substances 0.000 claims description 17
- 229920002379 silicone rubber Polymers 0.000 claims description 9
- 230000003321 amplification Effects 0.000 claims description 7
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 7
- 239000004945 silicone rubber Substances 0.000 claims description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 239000010949 copper Substances 0.000 claims description 5
- 230000003139 buffering effect Effects 0.000 claims description 4
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 claims 1
- 230000001012 protector Effects 0.000 abstract description 5
- 238000000034 method Methods 0.000 abstract description 3
- 238000004804 winding Methods 0.000 description 13
- 230000005540 biological transmission Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 8
- 238000001514 detection method Methods 0.000 description 7
- 238000005259 measurement Methods 0.000 description 7
- 238000005457 optimization Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 239000002253 acid Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
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- 238000005516 engineering process Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The utility model discloses a kind of active faint power current inductive coil, comprise flexible inductive coil, sampling and integrating circuit, active differential amplifying circuit and voltage follower; Wherein, flexible inductive coil, for being converted to ac current signal by the magnetic field of being coupled to and exporting sampling and integrating circuit to; Sampling and integrating circuit, for sampling the ac current signal received, obtaining power-frequency voltage signal and exporting active differential amplifying circuit to; Active differential amplifying circuit, exports voltage follower to after being amplified by the power-frequency voltage signal of reception; Voltage follower, the power-frequency voltage signal for isolating, after Hyblid Buffer Amplifier, output voltage signal.The utility model adopts non-contacting method, detects the power frequency leakage current of surge protection device easily, is widely used in the test item of the power frequency leakage current of lightning protection device surge protector.
Description
Technical Field
The utility model relates to a thunder and lightning science and technical field, especially an active weak power frequency current induction coil.
Background
Lightning current is a typical transient current pulse, and the occurrence of lightning strike on a power transmission line often causes phenomena such as open circuit, short circuit and insulation performance change of the power transmission line. According to the design requirements of building lightning protection design specifications GB50057-2010, a surge protector is installed in a power transmission line and used for releasing and inhibiting the energy of lightning waves. The surge protector can release and restrain the energy of the lightning waves, and simultaneously can convert certain energy of the lightning waves into heat energy, so that the performance of the surge protector is deteriorated. Degradation often occurs as open circuits, short circuits, and power frequency leakage currents of the devices become large. The former two phenomena are easy to detect and obvious. However, the power frequency leakage current of the device is not easy to detect, but the power frequency leakage current of the device can cause certain influence on the power transmission line, and the power transmission line cannot work normally due to the fact that the power transmission line leakage current protection device trips because of large leakage current. The leakage current becomes large, and the device generates heat, causing accidents such as fire and the like.
Therefore, the surge protection device installed on the power transmission line is periodically detected according to the detection requirement of the lightning protection device of the building. Currently, in the detection project, a conventional method is commonly used for detecting the power frequency leakage current of the surge protection device, and an alternating current ammeter is connected in series in a circuit of the surge protection device for measurement. However, this detection method is inconvenient and unsafe to operate.
How to overcome the defects of the prior art becomes a key difficult problem to be solved urgently in the field of the prior lightning science and technology.
Disclosure of Invention
The utility model aims to solve the technical problem that overcome prior art not enough and provide an active weak power frequency current induction coil, the utility model is used for the leakage current of surge protection device in the detection installation transmission line realizes detecting surge protection device's periodic performance in the lightning protection device.
The utility model discloses a solve above-mentioned technical problem and adopt following technical scheme:
according to the utility model, the active weak power frequency current induction coil comprises a flexible induction coil, a sampling and integrating circuit, an active differential amplifying circuit and a voltage follower; wherein,
the flexible induction coil is used for converting the coupled magnetic field into an alternating current signal and outputting the alternating current signal to the sampling and integrating circuit;
the sampling and integrating circuit is used for sampling the received alternating current signal and obtaining a power frequency voltage signal to output to the active differential amplifying circuit;
the active differential amplification circuit is used for amplifying the received power frequency voltage signal and outputting the amplified power frequency voltage signal to the voltage follower;
and the voltage follower is used for isolating and buffering the amplified power frequency voltage signal and outputting the voltage signal.
As a further optimization scheme of the active weak power frequency current induction coil of the utility model, the flexible induction coil comprises a flexible framework, a copper column inserted in the flexible framework and a lead densely wound on the flexible framework; the flexible induction coil has two outputs: a first output terminal and a second output terminal.
As the utility model discloses a further optimization scheme of active weak power frequency current induction coil, flexible skeleton is the insulating silicone rubber tube, the wire is soft high temperature wire.
As a further optimization scheme of the active weak power frequency current induction coil of the utility model, the sampling and integrating circuit comprises a first resistor, a second resistor and a capacitor; wherein,
one end of the first resistor is connected with one end of the second resistor and the first output end respectively, the other end of the second resistor is connected with one end of the capacitor, and the other end of the first resistor is connected with the second output end and the other end of the capacitor respectively.
As a further optimization scheme of the active weak power frequency current induction coil of the present invention, the active differential amplification circuit includes a third resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth voltage follower; wherein,
one end of a third resistor is connected with one end of the capacitor, the other end of the third resistor is respectively connected with one end of a fifth resistor and the negative input end of a first voltage follower, the positive input end of the first voltage follower is grounded, the output end of the first voltage follower is connected with one end of a seventh resistor, the other end of the seventh resistor is respectively connected with one end of a ninth resistor and the negative input end of the third voltage follower, and the other end of the ninth resistor is connected with the output end of the third voltage follower; one end of a fourth resistor is connected with the other end of the capacitor, the other end of the fourth resistor is connected with one end of a sixth resistor and the negative input end of a second voltage follower, the positive input end of the second voltage follower is grounded, the other end of the sixth resistor is connected with the output end of the second voltage follower and one end of an eighth resistor respectively, the other end of the eighth resistor is connected with the positive input end of a third voltage follower and one end of a tenth resistor respectively, and the other end of the tenth resistor is grounded.
The utility model adopts the above technical scheme to compare with prior art, have following technological effect:
(1) the active weak power frequency current induction coil has a large measurement range, measures the power frequency current from 1 muA to 10mA, and meets the detection requirement of power frequency leakage current of the surge protector;
(2) the induction coil adopts an active amplifying circuit, the detection sensitivity is high, and the influence of a display load on the measurement precision is small;
(3) the induction framework is made of flexible silicon rubber materials, so that the induction framework has the advantages of moisture resistance, water resistance, good insulating property and safe use;
(4) when the induction coil is used for measurement, the induction coil is not in contact with a charged body, and the induction coil is convenient to operate, safe and reliable;
(5) the induction coil has high measurement precision and small error range, and the average measurement error is +/-1.03%;
(6) the induction coil is wide in application range, is also suitable for detecting the power frequency leakage current of the induction insulating terminal, conveniently detects the power frequency leakage current of a surge protection device, and is widely applied to detection items of the power frequency leakage current of a surge protection device of a lightning protection device. .
Drawings
Fig. 1 is a schematic block diagram of the present invention.
Fig. 2 is a structural diagram of the middle flexible induction coil of the present invention.
Fig. 3 is a circuit diagram of the sampling and integrating circuit of the present invention.
Fig. 4 is a circuit diagram of the middle active differential amplifier circuit and the voltage follower circuit of the present invention.
Detailed Description
The technical scheme of the utility model is further explained in detail with the attached drawings as follows:
fig. 1 shows a schematic block diagram of the present invention, and an active weak power frequency current induction coil according to the present invention comprises a flexible induction coil, a sampling and integrating circuit, an active differential amplifying circuit and a voltage follower; wherein,
the flexible induction coil is used for converting the coupled magnetic field into an alternating current signal and outputting the alternating current signal to the sampling and integrating circuit;
the sampling and integrating circuit is used for sampling the received alternating current signal to obtain a power frequency voltage signal and outputting the power frequency voltage signal to the active differential amplifying circuit;
the active differential amplification circuit is used for amplifying the received power frequency voltage signal and outputting the amplified power frequency voltage signal to the voltage follower, so that the sensitivity of the induction coil is improved;
and the voltage follower is used for isolating and buffering the amplified power frequency voltage signal, outputting the voltage signal and ensuring the strength of the output voltage signal.
Fig. 2 is a structural diagram of a flexible induction coil according to the present invention, wherein the flexible induction coil comprises a flexible framework, a copper column inserted into the flexible framework, and a wire densely wound on the flexible framework; the flexible induction coil has two outputs: a first output terminal and a second output terminal. The flexible framework is an insulating silicone rubber tube, and the wire is a soft high-temperature wire.
The principle of a flexible induction coil is to use the principle that a varying current on a conductor will generate a varying magnetic field. When a magnetic field is coupled to the coil, the coil induces an electrical signal. The framework of the flexible induction coil is an insulating silicon rubber tube with the inner diameter of 4mm, the outer diameter of 8mm and the length of 4cm, the framework plays a supporting role, and the framework has flexibility, and a copper column with the length of 2cm and the diameter of 4mm is inserted into one end of the framework, and the other end of the rubber tube is inserted into the framework, so that the rubber tube can be encircled into a closed loop. The induction coil on the framework should be wound more densely to improve the induction coefficient of the coil. When winding, the winding is firstly densely wound according to a certain direction, the winding is continued to the opposite direction after the winding reaches the tail end of the framework, and two wiring terminals (a first output end and a second output end) are reserved for connection of the sampling and integrating circuit and are used for providing induction signals for the post-sampling and integrating circuit. The wire used in winding should be a suitably flexible high temperature wire. The winding material and the winding mode of induction coil are decisive factors, and the more dense the winding the inductance factor of coil is bigger, and coil self-inductance and stray capacitance are bigger, and its upper limit frequency can reduce, and this kind of winding mode can not have great influence to power frequency current's measurement. According to the winding characteristics of the flexible coil, a 5-core high-temperature lead with the inner diameter of 0.5mm and the outer diameter of 1mm is selected, the inner lead has excellent corrosion resistance, acid resistance and alkali resistance, the insulating layer has excellent electrical insulating performance, and the flexible coil can resist high voltage and high temperature and has small high-frequency loss. According to the parameter requirements of the flexible coil, calculating according to an empirical formula:
l＝2n(b-a+h+d)
S1＝πd2/4
r＝ρl/S1；
Sc＝(h+d)(b-a+d)
in the formula, a is the inner diameter of the silicone rubber tube, b is the outer diameter of the silicone rubber tube, h is the height of the coil to be wound, d is the diameter of the wound wire, and S1Is the cross-sectional area of the wire, ScIs the sectional area of the coil, rho is the resistivity of the copper material, l is the length of the wire required,r is resistance; ρ 17.5n Ω · m, a 4mm, b 8mm, h 4.4 mm. The number of turns of the winding is 460 turns. The winding mode is close winding two layers, each layer has 230 turns. After the coil is wound, the periphery of the coil is packaged by the same silicone rubber tube, and the silicone rubber tube has the inner diameter of 10mm, the outer diameter of 14mm and the length of 25 cm. The first output terminal 1 and the second output terminal 2 of the coil are signal output terminals for connecting with the first resistor R1.
Fig. 3 is a diagram of a sampling and integrating circuit according to the present invention, which includes a first resistor R1, a second resistor R2, and a capacitor C; one end of the first resistor R1 is connected to one end of the second resistor R2 and the first output end, the other end of the second resistor R2 is connected to one end of the capacitor C, and the other end of the first resistor R1 is connected to the second output end and the other end of the capacitor C. The first resistor R1, the second resistor R2 and the capacitor C are arranged in a pi-type. The device parameter selection of the sampling and integrating circuit is calculated according to the parameters of the flexible coil to obtain: first resistance R1 ═ 275 Ω, where R2 ═ 100 Ω, and C ═ 8 μ F. The port 3 and the port 4 are respectively connected with the port 1 and the port 2 of the flexible coil port to provide signal input for the sampling and integrating circuit, and the port 5 and the port 6 are used as signal input ports of the next stage of active differential amplifying circuit and voltage follower circuit and are connected with the port 7 and the port 8 of the active differential amplifying circuit and voltage follower circuit. And the sampling and integrating circuit is used for sampling the received alternating current signal to obtain a power frequency voltage signal, and converting the current signal obtained by coupling the flexible coil into a voltage signal through the first resistor R1. R1 in the sampling resistance type sampling circuit utilizes the integrating circuit to realize that the voltage signal output to the active differential amplifying circuit is in direct proportion to the voltage signal on the first resistor R1.
Fig. 4 is a circuit diagram of an active differential amplifier circuit and a voltage follower circuit according to the present invention, the active differential amplifier circuit includes third to tenth resistors R3, R4, R5, R6, R7, R8, R9, R10, and the voltage follower includes a first voltage follower IC1, a second voltage follower IC2 and a third voltage follower IC 3; wherein,
one end of a third resistor R3 is connected with one end of a capacitor C, the other end of the third resistor R3 is connected with one end of a fifth resistor R5 and the negative input end of a first voltage follower IC1 respectively, the positive input end of the first voltage follower IC1 is grounded, the output end of the first voltage follower IC1 is connected with one end of a seventh resistor R7, the other end of the seventh resistor R7 is connected with one end of a ninth resistor R9 and the negative input end of a third voltage follower IC3 respectively, and the other end of the ninth resistor R9 is connected with the output end of the third voltage follower IC 3; one end of a fourth resistor R4 is connected with the other end of the capacitor C, the other end of the fourth resistor R4 is connected with one end of a sixth resistor R6 and the negative input end of a second voltage follower IC2, the positive input end of the second voltage follower IC2 is grounded, the other end of the sixth resistor R6 is connected with the output end of the second voltage follower IC2 and one end of an eighth resistor R8 respectively, the other end of the eighth resistor R8 is connected with the positive input end of a third voltage follower IC3 and one end of a tenth resistor R10 respectively, and the other end of the tenth resistor R10 is grounded.
The gain of the amplifying circuit formed by the first voltage follower IC1 and the second voltage follower IC2 is 100 times. The gain of an amplifying circuit formed by a third voltage follower IC3 is 1 time, a first voltage follower IC1 and a second voltage follower IC2 are composed of LM358 bidirectional operational amplifiers, a third voltage follower IC3 is composed of a single operational amplifier OP27, an input signal is connected to two ends of a capacitor C of an integrating circuit, the operational amplifier is powered by a +/-12V direct-current power supply, and the working process of the amplifier is as follows: the voltage signal from the integrating circuit is amplified by the first voltage follower IC1 and the second voltage follower IC2 and then is connected to the input end of the amplifying circuit formed by the third voltage follower IC3, the voltage signal is output from the output port 9, and the device parameters of the circuit are as follows: r3 ═ R4 ═ 1k Ω, R5 ═ R6 ═ 100k Ω, and R7 ═ R8 ═ R9 ═ R10 ═ 10k Ω.
The voltage follower is used for buffering and outputting the amplified signal, the rear end of the voltage follower is connected with a display load, and the influence of a display load device on the active differential amplification circuit is reduced so as to improve the stability of output.
The utility model discloses a complete working process is around flexible induction line on the wire, have the electric current to flow when in the wire and will respond to voltage signal on the first resistance R1 at flexible induction coil both ends, R1 through the integrating circuit recovers the electric current signal in the wire, the voltage waveform at electric current both ends is unanimous with the electric current waveform in the wire among the integrating circuit, the amplitude of voltage has certain corresponding relation with the electric current, amplify the back through active difference amplifier circuit, the signal of output adds voltage follower circuit and exports, the value of output can directly be taken through voltmeter or oscilloscope, reach the current value in the wire through certain conversion relation.
It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations to the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And such obvious changes and modifications which fall within the spirit of the invention are deemed to be covered by the present invention.
Claims (5)
1. An active weak power frequency current induction coil is characterized by comprising a flexible induction coil, a sampling and integrating circuit, an active differential amplification circuit and a voltage follower; wherein,
the flexible induction coil is used for converting the coupled magnetic field into an alternating current signal and outputting the alternating current signal to the sampling and integrating circuit;
the sampling and integrating circuit is used for sampling the received alternating current signal to obtain a power frequency voltage signal and outputting the power frequency voltage signal to the active differential amplifying circuit;
the active differential amplification circuit is used for amplifying the received power frequency voltage signal and outputting the amplified power frequency voltage signal to the voltage follower;
and the voltage follower is used for isolating and buffering the amplified power frequency voltage signal and outputting the voltage signal.
2. The active weak power frequency current induction coil according to claim 1, wherein the flexible induction coil comprises a flexible framework, copper columns inserted in the flexible framework and a lead wire tightly wound on the flexible framework in two layers; the flexible induction coil has two outputs: a first output terminal and a second output terminal.
3. The active weak power frequency current induction coil of claim 2, wherein the flexible framework is an insulating silicone rubber tube, and the wire is a flexible high-temperature wire.
4. The active weak power frequency current induction coil according to claim 2, wherein the sampling and integrating circuit comprises a first resistor, a second resistor and a capacitor; wherein,
one end of the first resistor is connected with one end of the second resistor and the first output end respectively, the other end of the second resistor is connected with one end of the capacitor, and the other end of the first resistor is connected with the second output end and the other end of the capacitor respectively.
5. The active weak power frequency current induction coil according to claim 4, wherein the active differential amplification circuit comprises a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a tenth resistor, a sixth voltage follower, a seventh voltage follower, a sixth voltage follower; wherein,
one end of a third resistor is connected with one end of the capacitor, the other end of the third resistor is respectively connected with one end of a fifth resistor and the negative input end of a first voltage follower, the positive input end of the first voltage follower is grounded, the output end of the first voltage follower is connected with one end of a seventh resistor, the other end of the seventh resistor is respectively connected with one end of a ninth resistor and the negative input end of the third voltage follower, and the other end of the ninth resistor is connected with the output end of the third voltage follower; one end of a fourth resistor is connected with the other end of the capacitor, the other end of the fourth resistor is connected with one end of a sixth resistor and the negative input end of a second voltage follower, the positive input end of the second voltage follower is grounded, the other end of the sixth resistor is connected with the output end of the second voltage follower and one end of an eighth resistor respectively, the other end of the eighth resistor is connected with the positive input end of a third voltage follower and one end of a tenth resistor respectively, and the other end of the tenth resistor is grounded.
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| CN201420638595.9U CN204154778U (en) | 2014-10-30 | 2014-10-30 | A kind of active faint power current inductive coil |
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| CN201420638595.9U CN204154778U (en) | 2014-10-30 | 2014-10-30 | A kind of active faint power current inductive coil |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104345196A (en) * | 2014-10-30 | 2015-02-11 | 南京信息工程大学 | Active weak power frequency current induction coil |
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| CN104345196A (en) * | 2014-10-30 | 2015-02-11 | 南京信息工程大学 | Active weak power frequency current induction coil |
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| TR01 | Transfer of patent right |
Effective date of registration: 20170713 Address after: 214500, 9, Pisces Road, Jingjiang, Jiangsu, Taizhou Patentee after: Jiangsu Huang Heng communication equipment manufacturing Co., Ltd. Address before: Zhongshan road Wuzhong District Mudu town of Suzhou city in Jiangsu province 215101 No. 70 Wuzhong Science Park Building 2 room 2310 Patentee before: Nanjing University of Information Science and Technology |
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| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150211 Termination date: 20201030 |