CN108226610B - Clamp type measuring device for alternating current and direct current small current - Google Patents
Clamp type measuring device for alternating current and direct current small current Download PDFInfo
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- CN108226610B CN108226610B CN201810218244.5A CN201810218244A CN108226610B CN 108226610 B CN108226610 B CN 108226610B CN 201810218244 A CN201810218244 A CN 201810218244A CN 108226610 B CN108226610 B CN 108226610B
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- 238000001514 detection method Methods 0.000 claims abstract description 156
- 238000004804 winding Methods 0.000 claims abstract description 114
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 104
- 239000003990 capacitor Substances 0.000 claims abstract description 12
- 230000008878 coupling Effects 0.000 claims abstract description 11
- 238000010168 coupling process Methods 0.000 claims abstract description 11
- 238000005859 coupling reaction Methods 0.000 claims abstract description 11
- 229910000889 permalloy Inorganic materials 0.000 claims description 7
- 238000000137 annealing Methods 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- 229910000976 Electrical steel Inorganic materials 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims 1
- 238000005259 measurement Methods 0.000 abstract description 5
- 238000010586 diagram Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
The invention discloses a clamp type measuring device for alternating current and direct current small current, which comprises a sensing head, a modulation transformer, a band-pass filter, a phase-sensitive demodulator, a direct current amplifier, a power amplifier, an alternating current filter amplifier, a coupling capacitor and a standard resistor, wherein the sensing head is connected with the modulation transformer; the sensing head comprises an upper half-ring U-shaped detection iron core and a lower half-ring U-shaped detection iron core, wherein the upper half-ring U-shaped detection iron core comprises a first half-ring detection iron core and a second half-ring detection iron core, and the lower half-ring U-shaped detection iron core comprises a third half-ring detection iron core and a fourth half-ring detection iron core; the first, second, third and fourth semi-ring detection iron cores are respectively wound with first, second, third and fourth modulation detection windings; the outer surfaces of the upper semi-ring U-shaped detection iron core and the lower semi-ring U-shaped detection iron core are respectively wound with a fifth alternating current detection winding and a sixth alternating current detection winding, the assembled semi-ring U-shaped detection iron core is integrally arranged in a semi-cavity of an annular magnetic shielding iron core formed by two semi-ring magnetic shielding iron cores, and the outer surface of the annular magnetic shielding iron core is wound with a feedback winding. The modulation detection winding and the alternating current detection winding respectively realize the direct current component and the alternating current component of the detected current, and further realize the measurement of alternating current and direct current small current.
Description
Technical Field
The invention belongs to current measuring equipment in the electrotechnical field, and particularly relates to a clamp-type measuring device for alternating current and direct current.
Background
The utility model provides a "direct current small current clamp type measuring device" of application number 201510854478.5, the problem that sensitivity, precision are not enough when current clamp type direct current measuring device is used for the small direct current measurement in industrial field, put forward the sensor head and be the clamp type structure of upper and lower two semi-rings, use permalloy material to constitute first semi-ring detection iron core and second semi-ring detection iron core in the U type of upper semi-ring detection iron core, and third semi-ring detection iron core and fourth semi-ring detection iron core in the U type of lower semi-ring detection iron core, upper and lower semi-ring is from forming confined U type detection iron core structure, not only realized permalloy material and need not mechanical cutting, the opening, guaranteed its perfect magnetic properties, realized the open-type of upper and lower semi-ring and namely clamp type structure, be applicable to industrial field application. This is significant for the field measurement of small direct currents. But has the following drawbacks: the industrial field AC and DC micro-current are ubiquitous, and can be used for measuring both DC and AC, so that the application prospect is more urgent for users, and the invention is the problem to be solved.
Disclosure of Invention
The invention provides a clamp type measuring device for alternating current and direct current small currents, which solves the problem that the existing sensing head and measuring device can only measure direct current small currents, and is used for measuring alternating current and direct current small currents by a simple and stable operation structure.
In order to achieve the above object, the present invention provides a clamp type measuring apparatus for an ac/dc small current, comprising:
the device comprises a sensing head, a modulating transformer, a band-pass filter, a phase-sensitive demodulator, a direct current amplifier, a power amplifier, an alternating current filter amplifier, a coupling capacitor and a standard resistor;
the sensing head comprises an upper semi-ring U-shaped detection iron core and a lower semi-ring U-shaped detection iron core, wherein the upper semi-ring U-shaped detection iron core comprises a first semi-ring detection iron core and a second semi-ring detection iron core which form a closed U-shaped structure, and the lower semi-ring U-shaped detection iron core comprises a third semi-ring detection iron core and a fourth semi-ring detection iron core which form a closed U-shaped structure;
the first modulation detection winding is wound outside the first half-ring detection iron core, the second modulation detection winding is wound outside the second half-ring detection iron core, the third modulation detection winding is wound outside the third half-ring detection iron core, and the fourth modulation detection winding is wound outside the fourth half-ring detection iron core; a fifth alternating current detection winding is wound outside the upper semi-ring U-shaped detection iron core, and a sixth alternating current detection winding is wound outside the lower semi-ring U-shaped detection iron core;
a first semi-ring detection iron core and a second semi-ring detection iron core which are wound with a first modulation detection winding, a second modulation detection winding and a fifth alternating current detection winding are arranged in a cavity of the first semi-ring magnetic shielding iron core; a third semi-ring detection iron core and a fourth semi-ring detection iron core which are wound with a third modulation detection winding, a fourth modulation detection winding and a sixth alternating current detection winding are arranged in a cavity of the second semi-ring magnetic shielding iron core; the first semi-annular magnetic shielding iron core and the second semi-annular magnetic shielding iron core form a circular ring shape, and the feedback winding is wound on the first semi-annular magnetic shielding iron core and the second semi-annular magnetic shielding iron core;
the synonym end of the first modulation detection winding is connected with the synonym end of the fourth modulation detection winding, and the synonym end of the third modulation detection winding is connected with the synonym end of the second modulation detection winding; the same-name end of the first modulation detection winding is connected with the same-name end of the modulation transformer secondary winding, the same-name end of the second modulation detection winding is connected to the different-name end of the modulation transformer secondary winding, and the different-name end of the fourth modulation detection winding and the different-name end of the third modulation detection winding are simultaneously connected with a grounding point; the center tap of the secondary winding of the modulating transformer is connected with the input end of a band-pass filter, the output end of the band-pass filter is connected to the input end of a phase-sensitive demodulator, the output end of the phase-sensitive demodulator is connected with the input end of a direct current amplifier, the output end of the direct current amplifier is connected with the input end of a power amplifier, the output end of the power amplifier is connected with the homonymous end of a feedback winding, and the homonymous end of the feedback winding is connected with a grounding point through a standard resistor; the same name end of the fifth alternating current detection winding is connected with a grounding point, the different name end of the fifth alternating current detection winding is connected to the same name end of the sixth alternating current detection winding, the different name end of the sixth alternating current detection winding is connected to the input end of the alternating current filter amplifier, the output end of the alternating current filter amplifier is connected to one end of the coupling capacitor, and the other end of the coupling capacitor is connected to the same name end of the feedback winding.
Further, the feedback winding is equally divided into two sections, one section is uniformly wound outside the first semi-annular magnetic shielding iron core, the other section is uniformly wound outside the second semi-annular magnetic shielding iron core, and the two equally divided feedback windings are connected through a wire.
Further, the upper semi-ring U-shaped detection iron core and the lower semi-ring U-shaped detection iron core are formed by winding permalloy into a U shape and then annealing.
Further, the first semi-annular magnetic shielding iron core and the second semi-annular magnetic shielding iron core are both made of cold-rolled silicon steel sheets which are coiled into semi-annular shapes after being annealed.
In general, the above technical solutions conceived by the present invention, compared with the prior art, enable the following beneficial effects to be obtained:
the invention winds the fifth alternating current detection winding outside the upper semi-ring U-shaped detection iron core, winds the sixth alternating current detection winding outside the lower semi-ring U-shaped detection iron core, connects the two alternating current detection windings in series through the lead, and forms the detection of alternating current signals in the primary current to be detected.
The fifth and sixth AC detection windings input the AC detection signal into the AC filter amplifier to obtain secondary AC current, which flows through the coupling capacitor, and input the secondary AC current into the feedback winding to obtain the magnetic potential balance W of the primary AC ampere-turn and the secondary AC ampere-turn P I 1A ＝W F I 2A Secondary ac current I 2A ＝(W P /W F )I 1A Accurately reflect the measured primary alternating current, and the ratio coefficient is a fixed turns ratio W P /W F The method comprises the steps of carrying out a first treatment on the surface of the The invention discloses a direct current small current clamp type measuring device which is used for realizing accurate measurement of an alternating current and direct current small current clamp type structure.
Drawings
FIG. 1 is a schematic diagram of a sensor head in a clamp-type measuring device for AC/DC small current according to the present invention;
FIG. 2 (a) is a schematic cross-sectional view of the upper part of the sensor head in the clamp-type measuring device for AC/DC small current according to the present invention; FIG. 2 (b) is a schematic cross-sectional view of the lower part of the sensor head in the clamp-type measuring device for AC/DC small current according to the present invention;
fig. 3 is a schematic circuit diagram of a clamp-on measuring device for ac/dc small current according to the present invention.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
As shown in FIG. 1, the sensor head of the present invention has a circular shape, the cross section of which is shown in FIG. 2 (a) and FIG. 2 (b), and the upper half-ring U-shaped detecting iron core A comprisesFirst semi-ring detecting iron core C forming closed U-shaped structure 1 And a second semi-ring detection iron core C 2 The lower semi-ring U-shaped detection iron core B comprises a third semi-ring detection iron core C forming a closed U-shaped structure 3 And a fourth semi-ring detection iron core C 4 The method comprises the steps of carrying out a first treatment on the surface of the The upper semi-ring U-shaped detection iron core A and the lower semi-ring U-shaped detection iron core B are formed by winding permalloy strips into U shapes and then annealing;
first semi-ring detection iron core C 1 The outside is wound with a first modulation detection winding W 1 Second semi-ring detection iron core C 2 The outside is wound with a second modulation detection winding W 2 Third semi-ring detection iron core C 3 The outside is wound with a third modulation detection winding W 3 Fourth semi-ring detection iron core C 4 The outside is wound with a fourth modulation detection winding W 4 . The outer surface of the upper semi-ring U-shaped detection iron core A is wound with a fifth alternating current detection winding W 5 A sixth alternating current detection winding W is wound outside the lower semi-ring U-shaped detection iron core B 6 The assembled whole body is arranged in a half cavity of an annular magnetic shielding iron core C consisting of a first semi-annular magnetic shielding iron core and a second semi-annular magnetic shielding iron core, and a feedback winding W is wound outside the annular magnetic shielding iron core C F The annular magnetic shielding iron core C is made of annealed cold-rolled silicon steel sheet.
The sensing head provided by the invention is provided with the fifth alternating current detection winding outside the upper semi-ring U-shaped detection iron core, the sixth alternating current detection winding outside the lower semi-ring U-shaped detection iron core, and the two alternating current detection windings are connected in series through the lead, so that the detection of alternating current signals in the primary current to be detected is formed, the acquisition of the alternating current detection signals can be realized by using the upper semi-ring U-shaped permalloy detection iron core and the lower semi-ring U-shaped permalloy detection iron core without additionally adding the detection iron core, and therefore, the upper semi-ring U-shaped detection iron core and the lower semi-ring U-shaped detection iron core can detect direct current and alternating current signals, and the effect of one core with multiple purposes is achieved.
FIG. 3 is a schematic diagram of a clamp-type measuring device for AC/DC small current, which comprises a sensor head, a modulation transformer T, a band-pass filter E, a phase-sensitive demodulator F, a DC amplifier G, an AC filter amplifier K, a power amplifier H, and a standard resistor R s Coupling capacitor C 0 。
Wherein the first modulation detects winding W 1 Different name end of (a) and fourth modulation detection winding W 4 Is connected with the homonymous end of the third modulation detection winding W 3 Is identical to the second modulation detection winding W 2 Is connected with the heteronym end of the file; first modulation detection winding W 1 The same-name end of the modulation transformer T secondary winding is connected with the same-name end of the modulation transformer T secondary winding, and the second modulation detection winding W 2 The homonymous terminal of the modulation transformer T is connected with the homonymous terminal of the modulation transformer T secondary winding, and the fourth modulation detection winding W 4 Is connected with the third modulation detection winding W 3 The different name ends of the two are simultaneously connected with a grounding point; the center tap of the secondary winding of the modulating transformer T is connected with the input end of a band-pass filter E, the output end of the band-pass filter E is connected with the input end of a phase-sensitive demodulator F, the output end of the phase-sensitive demodulator F is connected with the input end of a direct current amplifier G, the output end of the direct current amplifier G is connected with the input end of a power amplifier H, and the output end of the power amplifier H is connected with a feedback winding W F Is connected with the homonymous end of the feedback winding W F Through standard resistor R S Connecting with a grounding point; fifth alternating current detection winding W 5 Is connected with the grounding point, and a fifth alternating current detection winding W 5 Is connected to the sixth AC detection winding W 6 Is the same-name end of the sixth alternating current detection winding W 6 Is connected to the input end of the alternating current filter amplifier K, and the output end of the alternating current filter amplifier K is connected to the coupling capacitor C 0 Is coupled to one end of capacitor C 0 Is connected to the feedback winding W at the other end F Is the same as the terminal of the same name. Feedback winding W F The magnetic shielding iron core is equally divided into two sections, and is uniformly wound outside the magnetic shielding iron cores of the upper semicircular sensing head and the lower semicircular sensing head respectively and connected through a wire.
After the device is put into operation, a fifth alternating current detection winding W 5 And a sixth alternating current detection winding W 6 The alternating current detection signals are overlapped, and the overlapped signals are input into an alternating current filter amplifier K to obtain secondary alternating current I 2A Via coupling capacitor C 0 Input feedback winding W F Obtaining a measured alternating current I 1A And secondary alternating current I 2A Is balanced by ampere-turn magnetic potentialW P I 1A ＝W F I 2A Secondary ac current I 2A ＝(W P /W F )I 1A Accurately reflect the primary alternating current I to be measured 1A The ratio coefficient is a fixed turns ratio W P /W F The method comprises the steps of carrying out a first treatment on the surface of the The invention discloses a direct current small current clamp type measuring device which is used for realizing accurate measurement of an alternating current and direct current small current clamp type structure.
It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (2)
1. A clamp-on measuring device for small alternating and direct currents, comprising: the sensor head, the modulation transformer (T), the band-pass filter (E), the phase-sensitive demodulator (F), the direct current amplifier (G), the power amplifier (H), the alternating current filter amplifier (K), the coupling capacitor (C) 0 ) Standard resistor (R) s )；
The sensing head comprises an upper semi-ring U-shaped detection iron core and a lower semi-ring U-shaped detection iron core, wherein the upper semi-ring U-shaped detection iron core comprises a first semi-ring detection iron core (C 1 ) And a second half ring detecting core (C) 2 ) The lower half-ring U-shaped detection iron core comprises a third half-ring detection iron core (C) 3 ) And a fourth half ring detecting core (C) 4 )；
First semi-ring detecting iron core (C) 1 ) The outside is wound with a first modulation detection winding (W 1 ) Second half ring detection core (C) 2 ) The outside is wound with a second modulation detection winding (W 2 ) Third semi-ring detecting iron core (C) 3 ) The outside is wound with a third modulation detection winding (W 3 ) Fourth semi-ring detecting iron core (C) 4 ) The outside is wound with a fourth modulation detection winding (W 4 ) The method comprises the steps of carrying out a first treatment on the surface of the A fifth alternating current detection winding (W) is wound outside the upper semi-ring U-shaped detection iron core 5 ) A sixth alternating current detection winding (W) 6 )；
Is wound with a first modulation detection winding (W 1 ) A second modulation detection winding (W 2 ) Fifth alternating current detection winding (W) 5 ) Is a first half-ring detection core (C) 1 ) And a second half ring detecting core (C) 2 ) The first semi-annular magnetic shielding iron core is arranged in the cavity of the first semi-annular magnetic shielding iron core; is wound with a third modulation detection winding (W 3 ) Fourth modulation detection winding (W) 4 ) Sixth alternating current detection winding (W) 6 ) Is a third half ring detection core (C) 3 ) And a fourth half ring detecting core (C) 4 ) The second semi-annular magnetic shielding iron core is arranged in the cavity of the second semi-annular magnetic shielding iron core; the first semi-annular magnetic shielding iron core and the second semi-annular magnetic shielding iron core form a circular ring shape, and the feedback winding is wound on the first semi-annular magnetic shielding iron core and the second semi-annular magnetic shielding iron core;
the first modulation detection winding (W 1 ) Is connected with a fourth modulation detection winding (W 4 ) Is connected to the same-name end of the third modulation detection winding (W 3 ) Is identical to the second modulation detection winding (W 2 ) Is connected with the heteronym end of the file; first modulation detection winding (W 1 ) Is connected to the homonymous terminal of the secondary winding of the modulating transformer (T), and the second modulating detection winding (W 2 ) Is connected to the synonym end of the secondary winding of the modulation transformer (T), the fourth modulation detection winding (W 4 ) Is connected with a third modulation detection winding (W 3 ) The different name ends of the two are simultaneously connected with a grounding point; the center tap of the secondary winding of the modulating transformer (T) is connected with the input end of a band-pass filter, the output end of the band-pass filter (E) is connected with the input end of a phase-sensitive demodulator (F), the output end of the phase-sensitive demodulator (F) is connected with the input end of a direct current amplifier (G), the output end of the direct current amplifier (G) is connected with the input end of a power amplifier (H), the output end of the power amplifier (H) is connected with the homonymous end of a feedback winding, and the heteronymous end of the feedback winding is connected with a reference resistor (R s ) Connecting with a grounding point; fifth alternating current detection winding (W) 5 ) Is connected to the ground point, and a fifth ac detection winding (W 5 ) Is connected to the sixth alternating current detection winding (W 6 ) Is identical to the same-name end of the sixth alternating current detection winding (W 6 ) Is connected to the alternating current filtering amplificationAn input of the filter (K), an output of the alternating current filter amplifier (K) is connected to a coupling capacitor (C) 0 ) Is connected to one end of the coupling capacitor (C 0 ) The other end of the feedback winding is connected to the same-name end of the feedback winding;
the upper semi-ring U-shaped detection iron core and the lower semi-ring U-shaped detection iron core are formed by winding permalloy strips into U shapes and then annealing;
the first semi-annular magnetic shielding iron core and the second semi-annular magnetic shielding iron core are made of cold-rolled silicon steel sheets which are coiled into semi-annular shapes after annealing treatment.
2. The clamp measuring device of claim 1, wherein the feedback winding is equally divided into two sections, one section is evenly wound around the first semi-annular magnetic shielding core, the other section is evenly wound around the second semi-annular magnetic shielding core, and the two equally divided feedback windings are connected by a wire.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810218244.5A CN108226610B (en) | 2018-03-16 | 2018-03-16 | Clamp type measuring device for alternating current and direct current small current |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810218244.5A CN108226610B (en) | 2018-03-16 | 2018-03-16 | Clamp type measuring device for alternating current and direct current small current |
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| CN108226610A CN108226610A (en) | 2018-06-29 |
| CN108226610B true CN108226610B (en) | 2023-12-26 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109870664A (en) * | 2019-03-28 | 2019-06-11 | 北京大学 | A kind of magnetic field measurement system and measurement method |
| FR3137177A1 (en) * | 2022-06-23 | 2023-12-29 | Chauvin Arnoux | Clamp meter for AC and DC leakage currents |
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| CN103308743A (en) * | 2013-05-24 | 2013-09-18 | 华中科技大学 | Direct current metering device |
| CN105353193A (en) * | 2015-11-27 | 2016-02-24 | 华中科技大学 | Low direct current clamp-shaped measuring device |
| CN208140774U (en) * | 2018-03-16 | 2018-11-23 | 华中科技大学 | A kind of clamp measuring device for alternating current-direct current low current |
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2018
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|---|---|---|---|---|
| SU1252733A1 (en) * | 1984-01-13 | 1986-08-23 | Предприятие П/Я В-8799 | Device for contactless measuring of interference currents |
| CN1079053A (en) * | 1992-05-21 | 1993-12-01 | 华中理工大学 | A kind of AC/dc current comparison instrument |
| CN1109975A (en) * | 1995-02-24 | 1995-10-11 | 华中理工大学 | DC and AC three-purpose current comparator |
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