CN111157775A - Double-coil current sensor - Google Patents
Double-coil current sensor Download PDFInfo
- Publication number
- CN111157775A CN111157775A CN201911143132.9A CN201911143132A CN111157775A CN 111157775 A CN111157775 A CN 111157775A CN 201911143132 A CN201911143132 A CN 201911143132A CN 111157775 A CN111157775 A CN 111157775A
- Authority
- CN
- China
- Prior art keywords
- induction coils
- current
- induction
- measuring device
- coil
- 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.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
- G01R15/183—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using transformers with a magnetic core
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
The invention discloses a double-coil current sensor, which belongs to the technical field of current sensors and comprises a measuring device and two groups of induction coils connected with the measuring device, wherein the two groups of induction coils are equal in turn number and area, one group of the two groups of induction coils is connected with a homopolar end, the other group of the two groups of induction coils is connected with the positive electrode and the negative electrode of the measuring device respectively, and current to be measured passes through one group of the induction coils. The method has the advantages of reducing the influence of the magnetic field of the surrounding environment on current measurement and improving the accuracy of the current measurement, particularly the small current measurement.
Description
Technical Field
The invention relates to the technical field of current sensors, in particular to a double-coil current sensor.
Background
In the power industry, in order to meet the requirements of protecting, metering or monitoring power equipment and systems, various currents need to be measured, and current measuring methods mainly comprise an access type, an induction type and a remote measuring type according to measured objects and field environments. The main detection tools include an ammeter, a current sensor (or a current transformer and a CT), an electronic induction type transformer, a photoelectric induction type transformer and the like.
The detection of leakage current is mainly applied to the protection and monitoring of various primary devices, and in a transformer substation with various voltage levels, a transmission tower or other occasions needing grounding protection of the devices, because the flowing current is very weak (microampere uA-milliampere mA), under the condition of strong electromagnetic field interference of the transformer substation or the transmission line and the like, the safe, reliable and accurate measurement and monitoring of the current is particularly important for the safe operation of each primary device in the transformer substation, but aiming at the characteristics of a power system, such as the open air environment, strong surrounding interference factors and no external power supply support, the measured device does not allow the factors such as the original structure to be changed, and the situation can only use series-in type measurement.
As shown in fig. 1, a conventional current sensor includes a measuring device and a measuring coil, when a current to be measured approaches, an induced current is generated in the coil and transmitted to the measuring device, so as to measure the current. However, the interference magnetic field exists in the environmental space, and the interference magnetic field can also cause the coil to generate induced current, so that the measurement result is influenced, and particularly when small current is detected, the interference magnetic field has a large influence on the measurement value.
Disclosure of Invention
The invention provides a double-coil current sensor which has the advantages that the influence of a magnetic field of the surrounding environment on current measurement can be reduced, and the accuracy of current measurement, particularly small current measurement, is improved.
The above object of the present invention is achieved by the following technical solution, in which a dual coil current sensor includes a measuring device and two sets of induction coils connected to the measuring device, the two sets of induction coils have equal turns and equal areas, one of the two sets of induction coils has a same polarity end connected to the same end, the other set of the two sets of induction coils has a same polarity end connected to the positive and negative electrodes of the measuring device, and a current to be measured passes through one of the sets of induction coils.
The invention is further arranged that the induction coil is a fixed coil with a fixed area.
The invention is further provided that the induction coil is made of a hard wire.
The invention is further configured such that the induction coil is formed by winding a wire around a ceramic support.
The invention is further arranged that iron cores with the same specification are arranged in the two groups of induction coils.
The invention has the beneficial effects that when the current is detected, the two induction coils are arranged in parallel, and the current to be measured passes through one induction coil. Because the distribution range of the interference magnetic field in the environment is usually large, and the area of the induction coil is very small compared with the range of the interference magnetic field, it can be considered that the induction magnetic fields contacted by the two induction coils are the same, so that the induced electromotive forces generated by the interference magnetic field on the two induction coils are equal. And because a group of homopolar ends of the two induction coils are connected, namely the anodes or the cathodes of the two induction coils are connected, correspondingly, the cathodes of the two induction coils are respectively connected with the anode and the cathode of the measuring device or the anodes of the two induction coils are connected with the anode and the cathode of the measuring device, and the induced electromotive forces of the two induction coils are superposed and offset. The current to be measured passes through one of the induction coils, an electromotive force is induced at the position generated on the induction coil and is connected to the measuring device, and the potential difference or the current value measured by the measuring device is the induced electromotive force or the induced current generated by the current to be measured, so that the influence caused by an interference magnetic field is reduced.
Drawings
FIG. 1 is a schematic diagram of a conventional current sensor of the background art;
FIG. 2 is a schematic view of the overall structure of the present embodiment;
fig. 3 is a waveform diagram illustrating induced electromotive forces generated in the induction coil a and the induction coil B by the disturbing magnetic field in the present embodiment;
fig. 4 is a waveform diagram of the induced electromotive force E generated by the current to be measured on the induction coil a in this embodiment.
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings.
Example (b): the double-coil current sensor comprises a measuring device and induction coils connected with the measuring device, wherein the induction coils are divided into two groups, the two groups of induction coils are equal in number of turns and area, one group of homopolar ends of the two induction coils are connected, the other group of homopolar ends are respectively connected with the positive pole and the negative pole of the measuring device, namely the positive poles of the two induction coils are connected or the negative poles of the two induction coils are connected, correspondingly, the negative poles of the two induction coils are respectively connected with the positive pole and the negative pole of the measuring device or the positive poles of the two induction coils are connected with the positive pole and the negative pole of the measuring device, and a current to be measured passes.
In order to ensure that the areas of the two induction coils are equal in the using process, the induction coils are fixed coils with fixed areas, and specifically, the induction coils are made of hard wires, so that the areas of the induction coils are not easy to change; or the induction coil is formed by winding a lead on the ceramic support piece, and the area of the induction coil is not easy to change due to the support of the ceramic support piece.
As shown in fig. 2, in the embodiment of the present invention, the two induction coils are an induction coil a and an induction coil B, respectively, positive poles of the induction coil a and the induction coil B are connected by a lead, and negative poles of the induction coil a and the induction coil B are connected to a positive pole and a negative pole of the measuring device, respectively. The measuring device is a measuring device in existing equipment such as a current sensor, an electronic induction transformer, and the like, and is not described herein again.
When the current is detected, the induction coil A and the induction coil B are arranged in parallel, and the current to be measured passes through the induction coil A. Because the distribution range of the interference magnetic field in the environment is often large, and the area of the induction coil is very small compared with the range of the interference magnetic field, it can be considered that the induction magnetic fields contacted by the induction coil a and the induction coil B are the same, so that the induced electromotive forces generated by the interference magnetic field on the two induction coils are equal. Let the equivalent current of the disturbing magnetic field be I0Let E be the electromotive force generated by the interference magnetic field on the induction coil A0AThe induced electromotive force generated in the induction coil B is E0BThen E is0AAnd E0BAre equal.
The positive poles of the induction coil A and the induction coil B are connected, correspondingly, the negative poles of the induction coil A and the induction coil B are respectively connected with the positive pole and the negative pole of the measuring device, so that the positive pole and the negative pole of the measuring device are used as judgment references, and E0AAnd E0BIn opposite phase as shown in fig. 3.
Assuming that the current to be measured is I, the induced electromotive force generated by the current to be measured on the induction coil a is E, and when the current to be measured I is ac, the induced electromotive force is E is also ac, as shown in fig. 4, the electromotive force E = E + E at the input end of the measuring device0A+E0BI.e. E = E, the influence of the disturbing magnetic field is eliminated.
In order to measure the micro current conveniently, iron cores with the same specification are arranged in the two groups of induction coils, and the iron cores can strengthen the influence of a weak magnetic field generated by the micro current. Meanwhile, the iron cores with the same specification are arranged in the two groups of induction coils, so that the measuring error caused by the fact that the interference magnetic field is only strengthened in the induction coil on one side is avoided, the interference magnetic field can be simultaneously strengthened by the iron cores in the two induction coils, and the influence of the interference magnetic field can be correctly counteracted when the small current is detected.
It should be noted that the direction of the current in fig. 2 only represents a current direction at a certain instant, and does not represent a definite flow direction of the current; the waveforms in FIG. 3 are for illustration E only0AAnd E0BA schematic diagram of the relationship, not a waveform diagram in the real case; the waveform in fig. 4 is only a schematic diagram of the induced electromotive force E generated on the induction coil a by the current to be measured, and is not an actual waveform diagram.
The using method comprises the following steps: when the coil current sensor is used for measuring current, the two groups of induction coils are placed in the same direction, so that magnetic fluxes of interference magnetic fields in the environment passing through the two induction coils are equal. And passing the current to be measured through one group of induction coils for measurement.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications are all within the scope of the present invention.
Claims (5)
1. A double-coil current sensor comprises a measuring device and induction coils connected with the measuring device, and is characterized in that the induction coils are divided into two groups, the two groups of induction coils are equal in number of turns and area, one group of homopolar ends of the two induction coils are connected, the other group of homopolar ends are respectively connected with the positive pole and the negative pole of the measuring device, and current to be measured passes through one group of induction coils.
2. A dual coil current sensor according to claim 1, wherein the induction coil is a fixed coil of fixed area.
3. A dual coil current sensor according to claim 2, wherein the induction coil is made of a hard wire.
4. A dual coil current sensor according to claim 2, wherein the induction coil is a wire wound on a ceramic support.
5. A dual coil current sensor according to any one of claims 1 to 4, wherein cores of the same size are provided in both sets of induction coils.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911143132.9A CN111157775A (en) | 2019-11-20 | 2019-11-20 | Double-coil current sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911143132.9A CN111157775A (en) | 2019-11-20 | 2019-11-20 | Double-coil current sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111157775A true CN111157775A (en) | 2020-05-15 |
Family
ID=70556046
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911143132.9A Pending CN111157775A (en) | 2019-11-20 | 2019-11-20 | Double-coil current sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111157775A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101521374A (en) * | 2008-11-18 | 2009-09-02 | 李晓明 | Short-circuit current limiting device of magnetic saturation reactor |
| CN201749142U (en) * | 2010-06-23 | 2011-02-16 | 浙江永泰隆电子有限公司 | Double-coil current sensor |
| CN103337355A (en) * | 2013-07-09 | 2013-10-02 | 河北申科电子股份有限公司 | Zero-magnetic flux current transformer capable of preventing electricity from being stolen through high-intensity magnetic field |
| JP2015232489A (en) * | 2014-06-10 | 2015-12-24 | 株式会社寺田電機製作所 | Current measuring device |
| CN107356800A (en) * | 2017-07-04 | 2017-11-17 | 西安交通大学 | The high-current detector and method of a kind of magnetic field cancellation |
| CN109975595A (en) * | 2019-04-08 | 2019-07-05 | 山东大学 | A kind of leakage current sensor and device of anti-power frequency magnetic field interference |
| CN209657980U (en) * | 2019-05-30 | 2019-11-19 | 山东元星电子有限公司 | A kind of current detecting mutual inductor of anti-strong magnetic field circumstance interference |
-
2019
- 2019-11-20 CN CN201911143132.9A patent/CN111157775A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101521374A (en) * | 2008-11-18 | 2009-09-02 | 李晓明 | Short-circuit current limiting device of magnetic saturation reactor |
| CN201749142U (en) * | 2010-06-23 | 2011-02-16 | 浙江永泰隆电子有限公司 | Double-coil current sensor |
| CN103337355A (en) * | 2013-07-09 | 2013-10-02 | 河北申科电子股份有限公司 | Zero-magnetic flux current transformer capable of preventing electricity from being stolen through high-intensity magnetic field |
| JP2015232489A (en) * | 2014-06-10 | 2015-12-24 | 株式会社寺田電機製作所 | Current measuring device |
| CN107356800A (en) * | 2017-07-04 | 2017-11-17 | 西安交通大学 | The high-current detector and method of a kind of magnetic field cancellation |
| CN109975595A (en) * | 2019-04-08 | 2019-07-05 | 山东大学 | A kind of leakage current sensor and device of anti-power frequency magnetic field interference |
| CN209657980U (en) * | 2019-05-30 | 2019-11-19 | 山东元星电子有限公司 | A kind of current detecting mutual inductor of anti-strong magnetic field circumstance interference |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8773139B2 (en) | High sensitivity differential current transformer for insulation health monitoring | |
| CN103308743B (en) | Direct current metering device | |
| Emanuel et al. | Current harmonics measurement by means of current transformers | |
| CN203191419U (en) | Intelligent electricity meter with diamagnetic structured electromagnetic current transformers | |
| CN103592490B (en) | A kind of high accuracy electronic compensation type current transformer | |
| CN106771477B (en) | Large-caliber high-sensitivity high-voltage direct current cable leakage current detection sensor | |
| CN109975595B (en) | Leakage current sensor and device for resisting interference of power frequency magnetic field | |
| CN105067868A (en) | Current measuring method and device | |
| CN111771250A (en) | Current transformer | |
| CN109031075A (en) | Multi-wire core insulation automatic detector and system | |
| WO2019092850A1 (en) | Ground fault point locating system and ground fault point locating method | |
| CN102445583A (en) | Detection method for voltage signals of power energy quality monitoring device and circuit as well as application thereof | |
| CN105510673A (en) | Direct current measuring device | |
| Bessolitsyn et al. | Experimental study of current error of up to 50 hz current-measuring transformer | |
| CN110836987B (en) | Manganese-copper shunt of three-phase intelligent electric energy meter and application thereof | |
| CN111157775A (en) | Double-coil current sensor | |
| CN207798899U (en) | A kind of current sensor and monitoring system | |
| CN202940118U (en) | High-current high-precision direct-current current transformer | |
| CN203561688U (en) | Monitoring device and system for grounding current of transformer | |
| CN106291061B (en) | A kind of current sensor, processing module and current measuring method | |
| KR102039268B1 (en) | An Alternating and Direct Current Detection Circuit | |
| CN212568917U (en) | Electronic current sensor for electric energy meter | |
| US20050068020A1 (en) | Method and apparatus for determining a current in a conductor | |
| CN105548664A (en) | Optical current-measurement device | |
| CN105675952A (en) | Current measurement device and method, and manufacture method of current measurement device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200515 |