CN111239574A - Differential high-frequency current sensor for series arc fault signal acquisition - Google Patents
Differential high-frequency current sensor for series arc fault signal acquisition Download PDFInfo
- Publication number
- CN111239574A CN111239574A CN202010301703.3A CN202010301703A CN111239574A CN 111239574 A CN111239574 A CN 111239574A CN 202010301703 A CN202010301703 A CN 202010301703A CN 111239574 A CN111239574 A CN 111239574A
- Authority
- CN
- China
- Prior art keywords
- arc fault
- current sensor
- frequency current
- fault signal
- series arc
- 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
- 230000005291 magnetic effect Effects 0.000 claims abstract description 58
- 239000004020 conductor Substances 0.000 claims abstract description 23
- 238000004804 winding Methods 0.000 claims abstract description 18
- 230000000149 penetrating effect Effects 0.000 claims abstract description 3
- 238000005070 sampling Methods 0.000 claims description 8
- 239000000696 magnetic material Substances 0.000 claims description 6
- 239000003822 epoxy resin Substances 0.000 claims description 3
- 229920000647 polyepoxide Polymers 0.000 claims description 3
- 239000012815 thermoplastic material Substances 0.000 claims description 3
- 230000007935 neutral effect Effects 0.000 claims description 2
- 238000005266 casting Methods 0.000 claims 1
- 230000009286 beneficial effect Effects 0.000 abstract description 3
- 230000004044 response Effects 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 230000004907 flux Effects 0.000 description 5
- 238000005259 measurement Methods 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 230000003750 conditioning effect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- 230000005355 Hall effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
-
- 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
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
The invention relates to a differential high-frequency current sensor for collecting series arc fault signals, which comprises a shell (6), wherein a magnetic ring (1) and a secondary winding (2) wound on the magnetic ring (1) are arranged in the shell (6), a primary conductor through hole (4) penetrating through the middle of the magnetic ring (1) is formed in the shell (6) so that a differential primary current-carrying conductor can penetrate through the shell, and an output terminal wire outlet groove (3) is formed in the shell (6) so that an output terminal (5) of the secondary winding (2) can penetrate through the shell. The sensor is beneficial to improving the accuracy, reliability and safety of series arc fault signal acquisition.
Description
Technical Field
The invention relates to the field of electronic sensing devices, in particular to a differential high-frequency current sensor for series arc fault signal acquisition.
Background
In a low-voltage distribution line, the steady-state current in a normal state can reach several amperes or even dozens of amperes, and the frequency is power frequency 50Hz, but experiments show that when a series arc fault occurs, the current amplitude basically does not change, but the arc current contains abundant noise, and the frequency can reach dozens of kHz or even more than MHz. Therefore, the high-frequency signal of the arc current is collected when the fault occurs, and the high-frequency signal can be used as the basis for the occurrence of the arc fault. In the series fault arc detection of a low-voltage distribution network, in order to detect high-frequency noise of current when an arc occurs, a current sensor capable of collecting transient and high-frequency current signals needs to be selected. The traditional current transformer made of silicon steel materials is suitable for collecting current signals within a power frequency range, but cannot be used for collecting high-frequency current signals. The high-frequency current sensor can collect low-power low-current high-frequency signals, but for a low-voltage distribution line with large current, a magnetic core of the high-frequency current sensor is easy to generate a saturation phenomenon, so that output signals are distorted, and the transmission characteristic is poor. In order to avoid the saturation phenomenon, the size of the magnetic flux inside the magnetic core is reduced by increasing the inner diameter and the outer diameter of the magnetic core, increasing the volume, opening an air gap on the magnetic core and the like, which limits the application range of the high-frequency current sensor.
The existing method for collecting the series fault arc current signals has the following defects and shortcomings: (1) the shunt is required to be connected into a tested line in series, the collected signal is a current signal in a full-frequency band range, a signal conditioning circuit is required to be added to filter the signal, and a high-frequency fault arc signal is obtained. (2) The electromagnetic current transformer is essentially a transformer, a primary side needs to be connected in series in a tested circuit, a secondary side cannot be opened, the transformer is not electrically isolated from the tested circuit, and the safety problem of a human body and an instrument still cannot be guaranteed. (3) The Hall effect sensor has stable and reliable performance, can measure direct current, alternating current and complex current waveforms, and is electrically isolated on the primary side and the secondary side. But the measurement bandwidth is narrow, the response time is long, the temperature drift is large, the eddy current loss is large when the high frequency is measured, and the method is not suitable for measuring the high frequency fault current signal. (4) The hollow Rogowski coil has good linearity and a bandwidth reaching MHz, does not have the problem of magnetic core saturation, and is an ideal high-frequency current sensor. However, the air core of the hollow Rogowski coil has relative magnetic permeability of about 1 due to the absence of a ferromagnetic core, and the induced voltage of a secondary winding is very small, so that the measurement sensitivity is very low. (5) To increase the output response, a magnetic core rogowski coil is mostly used. According to the characteristics of the arc current of the series fault arc of the low-voltage distribution network, the high-frequency magnetic material can be considered to be used as the magnetic core of the sensor, and the relative magnetic permeability of the high-frequency magnetic material is dozens of times or even thousands of times of that of the vacuum magnetic permeability, so that the induced voltage of the secondary winding can meet the measurement requirement. The magnetic core rogowski coil has much larger response than the air core rogowski coil, but the application of the sensor is limited due to the problem of magnetic core saturation of the magnetic core rogowski coil. The saturation magnetic induction intensity of the high-frequency magnetic core is generally low, and if the measured current is too large, the working point of the magnetic core enters a saturation region of a magnetization curve, the magnetic conductivity of the magnetic core is sharply reduced, and the sensing effect is lost. (6) The arc fault current transformer needs to be installed on a trunk, when a low-power load branch is connected in parallel with a high-power load, if an arc fault occurs in the low-power load branch, a low current containing high-frequency noise can be shielded by a large current of the high-power load, and the problem is difficult to solve by a common current transformer.
Disclosure of Invention
The invention aims to provide a differential high-frequency current sensor for series arc fault signal acquisition, which is beneficial to improving the accuracy, reliability and safety of series arc fault signal acquisition.
In order to achieve the purpose, the technical scheme of the invention is as follows: the utility model provides a difference formula high frequency current sensor for series connection electric arc fault signal gathers, includes casing (6), be equipped with magnetic ring (1) in casing (6) and around secondary winding (2) of locating on magnetic ring (1), set up on casing (6) and pierce through (4) from the primary conductor that magnetic ring (1) middle part passed to let the primary current-carrying conductor of difference formula pass, set up output terminal outlet groove (3) on casing (6) to let output terminal (5) of secondary winding (2) wear out.
Further, the primary conductor perforation (4) comprises two through holes arranged in parallel to pass through the neutral wire and the live wire simultaneously when in use.
Furthermore, the magnetic ring (1) is a high-frequency magnetic ring made of high-frequency soft magnetic materials, and the magnetic ring is magnetized by the measured current on the primary current-carrying conductor and alternates along with the alternation of the measured current.
Further, the winding angle of the secondary winding (2) is smaller than 360 degrees, namely the magnetic ring (1) is not fully wound.
Furthermore, the output terminal wire outlet groove (3) is arranged below the shell (6), and the output terminal (5) penetrates out and then is connected with the sampling resistor to output sampling signals.
Further, epoxy resin or thermoplastic material is filled between the magnetic ring (1) and the shell (6) so as to cast and mold the sensor.
Further, the differential high-frequency current sensor is applied to a trunk of a line section to be protected.
Compared with the prior art, the invention has the following beneficial effects:
(1) the sensor collects high-frequency signals of arc current in a differential threading mode, namely a live wire and a zero line simultaneously penetrate through the transformer, so that a magnetic field generated by most of current can be offset, residual magnetic flux (flux linkage) in the magnetic core is very small, the magnetic core always works in a low magnetic flux density state, the problem of magnetic core saturation cannot occur, and the problem of magnetic core saturation caused by overlarge current in arc fault detection of a low-voltage distribution network by the high-frequency current transformer is solved.
(2) The sensor is electrically isolated from a circuit to be measured, and can convert a high-frequency signal of a primary side current-carrying conductor when a series arc fault occurs into voltage acquisition and output only by depending on a magnetic coupling principle, so that the safety problem of operators and measuring instruments caused by the connection of a traditional shunt and an electromagnetic current transformer with the circuit to be measured is avoided.
(3) The sensor is applied to collecting high-frequency current signals when series fault arcs occur, the problem of distinguishing the series fault arcs of single loads and most of high-power shielding loads is effectively solved, and the problems of misjudgment and misjudgment caused by collecting low-frequency current signals when faults occur by using a current transformer in the prior art are avoided.
Drawings
Fig. 1 is a schematic structural view (with a front cover removed) of an embodiment of the present invention.
Detailed Description
The invention is described in further detail below with reference to the figures and the embodiments.
The invention provides a differential high-frequency current sensor for collecting series arc fault signals, which is applied to a trunk circuit of a line section to be protected, and comprises a shell 6, wherein a magnetic ring 1 and a secondary winding 2 wound on the magnetic ring 1 are arranged in the shell 6, a primary conductor through hole 4 penetrating through the middle of the magnetic ring 1 is formed in the shell 6 so as to allow a differential primary current-carrying conductor to penetrate through, and an output terminal wire outlet groove 3 is formed in the shell 6 so as to allow an output terminal 5 of the secondary winding 2 to penetrate out. In the present embodiment, the housing 6 is composed of a main housing and a front cover, and fig. 1 is a schematic structural view of the sensor with the front cover removed.
The differential primary current-carrying conductor is provided with two current-carrying conductors, the currents on the two current-carrying conductors are in equal and opposite directions, the two current-carrying conductors vertically penetrate through the sensor, and the eccentricity of the two current-carrying conductors influences the mutual inductance of the primary conductor and the secondary winding of the sensor. The primary conductor perforation 4 comprises two through holes arranged in parallel so as to simultaneously pass through a zero line and a live line when in use, namely two current-carrying conductors of the differential primary current-carrying conductor.
In this embodiment, the magnetic ring 1 is a high-frequency magnetic ring made of a high-frequency soft magnetic material meeting the bandwidth requirement, and the magnetic ring is magnetized by the measured current on the primary current-carrying conductor and alternates with the alternation of the measured current. The high-frequency soft magnetic material may be ferrite, a magnetic powder core, or the like. The secondary winding 2 is made of copper core enameled wire, the winding angle of the copper core enameled wire is between 0 degree and 360 degrees, namely the copper core enameled wire is not fully wound around the magnetic ring 1, the preferred value is 180 degrees, but the copper core enameled wire is not limited to the angle, and the copper core enameled wire is used for generating induced voltage along with alternating magnetic flux on the magnetic ring. And an easily-cured insulating material such as epoxy resin or thermoplastic material is filled between the magnetic ring 1 and the shell 6 so as to cast and mold the sensor.
The output terminal wire outlet groove 3 is arranged below the shell 6, and the output terminal 5 penetrates out to be connected with the sampling resistor to output sampling signals. And a non-inductive or low-inductive sampling resistor is connected in parallel to the double output terminals 5 led out from the output terminal wire outlet groove 3 so as to reduce the influence of the self inductance of the sampling resistor on the output response of the sensor.
In other embodiments of the present invention, annular metal sheets may be further installed on both sides of the vertical cross section of the sensor to serve as shielding cases to avoid possible interference of external magnetic fields.
The differential high-frequency current sensor overcomes the problems of small response of the hollow Rogowski coil and saturation of the magnetic core Rogowski coil, so that the output response of the secondary winding is larger, and the magnetic core cannot be saturated. The sensor can also overcome the problem of fault signal shielding caused by a high-power load to a low-power fault branch. The sensor can be effectively used for collecting series fault arc signals of a low-voltage distribution network, a subsequent signal conditioning circuit (an integrator and a filter circuit) is not needed, the requirement on hardware is low, and the cost is effectively reduced.
The above are preferred embodiments of the present invention, and all changes made according to the technical scheme of the present invention that produce functional effects do not exceed the scope of the technical scheme of the present invention belong to the protection scope of the present invention.
Claims (7)
1. The differential high-frequency current sensor for series arc fault signal acquisition is characterized by comprising a shell (6), wherein a magnetic ring (1) and a secondary winding (2) wound on the magnetic ring (1) are arranged in the shell (6), a primary conductor through hole (4) penetrating through the middle of the magnetic ring (1) is formed in the shell (6) so that a differential primary current-carrying conductor penetrates, and an output terminal wire outlet groove (3) is formed in the shell (6) so that an output terminal (5) of the secondary winding (2) penetrates out.
2. Differential high-frequency current sensor for series arc fault signal acquisition according to claim 1, characterized in that the primary conductor perforation (4) comprises two through holes arranged in parallel to pass through both the neutral and the live wire in use.
3. A differential high-frequency current sensor for series arc fault signal acquisition as claimed in claim 1, characterized in that the magnetic loop (1) is a high-frequency magnetic loop made of high-frequency soft magnetic material, magnetized by the measured current on the primary current-carrying conductor, alternating with the alternating of the measured current.
4. Differential high-frequency current sensor for series arc fault signal acquisition according to claim 1, characterized in that the winding angle of the secondary winding (2) is less than 360 °, i.e. not fully wound around the magnetic ring (1).
5. The differential high-frequency current sensor for series arc fault signal collection according to claim 1, wherein the output terminal outlet groove (3) is opened below the housing (6), and the output terminal (5) penetrates out and then is connected with a sampling resistor to output a sampling signal.
6. The differential high-frequency current sensor for series arc fault signal acquisition as claimed in claim 1, wherein the gap between the magnetic ring (1) and the housing (6) is filled with epoxy resin or thermoplastic material to mold the sensor by casting.
7. The differential high frequency current sensor for series arc fault signal acquisition of claim 1, wherein the differential high frequency current sensor is applied to a trunk of a line segment to be protected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010301703.3A CN111239574A (en) | 2020-04-16 | 2020-04-16 | Differential high-frequency current sensor for series arc fault signal acquisition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010301703.3A CN111239574A (en) | 2020-04-16 | 2020-04-16 | Differential high-frequency current sensor for series arc fault signal acquisition |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111239574A true CN111239574A (en) | 2020-06-05 |
Family
ID=70873782
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010301703.3A Pending CN111239574A (en) | 2020-04-16 | 2020-04-16 | Differential high-frequency current sensor for series arc fault signal acquisition |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111239574A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112444662A (en) * | 2020-10-27 | 2021-03-05 | 佛山市联动科技股份有限公司 | Current sensor and current sensing system |
| CN114172443A (en) * | 2021-12-01 | 2022-03-11 | 西南交通大学 | Online fault diagnosis method for current sensor of permanent magnet motor driving system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001242197A (en) * | 2000-02-25 | 2001-09-07 | Mitsubishi Electric Corp | Current detector |
| US20030058596A1 (en) * | 2000-03-04 | 2003-03-27 | Macbeth Bruce F. | Two winding resonating arc fault sensor which boosts arc fault signals while rejecting arc mimicking noise |
| CN104267241A (en) * | 2014-10-20 | 2015-01-07 | 国网吉林省电力有限公司长春供电公司 | High-frequency current partial discharge signal acquisition sensor |
| CN207268977U (en) * | 2017-07-13 | 2018-04-24 | 金华市奥凯电器有限公司 | A kind of electronic current mutual inductor |
| CN208399579U (en) * | 2018-04-11 | 2019-01-18 | 胡春生 | A kind of novel 10kV/35kV Current Voltage sensor |
| CN212646872U (en) * | 2020-04-16 | 2021-03-02 | 福州大学 | Differential high-frequency current sensor |
-
2020
- 2020-04-16 CN CN202010301703.3A patent/CN111239574A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001242197A (en) * | 2000-02-25 | 2001-09-07 | Mitsubishi Electric Corp | Current detector |
| US20030058596A1 (en) * | 2000-03-04 | 2003-03-27 | Macbeth Bruce F. | Two winding resonating arc fault sensor which boosts arc fault signals while rejecting arc mimicking noise |
| CN104267241A (en) * | 2014-10-20 | 2015-01-07 | 国网吉林省电力有限公司长春供电公司 | High-frequency current partial discharge signal acquisition sensor |
| CN207268977U (en) * | 2017-07-13 | 2018-04-24 | 金华市奥凯电器有限公司 | A kind of electronic current mutual inductor |
| CN208399579U (en) * | 2018-04-11 | 2019-01-18 | 胡春生 | A kind of novel 10kV/35kV Current Voltage sensor |
| CN212646872U (en) * | 2020-04-16 | 2021-03-02 | 福州大学 | Differential high-frequency current sensor |
Non-Patent Citations (1)
| Title |
|---|
| 刘德军 等: "基于峰值指标和脉冲指标的串联电弧故障检测研究", 电器与能效管理技术, no. 16, 31 December 2017 (2017-12-31), pages 6 - 10 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112444662A (en) * | 2020-10-27 | 2021-03-05 | 佛山市联动科技股份有限公司 | Current sensor and current sensing system |
| CN114172443A (en) * | 2021-12-01 | 2022-03-11 | 西南交通大学 | Online fault diagnosis method for current sensor of permanent magnet motor driving system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2203833C (en) | A device for sensing of electric discharges in a test object | |
| CN106018939B (en) | A kind of wide range Transient Transformer based on tunnel magneto | |
| CN106771477B (en) | Large-caliber high-sensitivity high-voltage direct current cable leakage current detection sensor | |
| CN210071931U (en) | Automatic detection device for B-type residual current size and type | |
| CN110824229B (en) | Single-magnetic-core multi-winding magnetic balance type current detection device | |
| CN111239574A (en) | Differential high-frequency current sensor for series arc fault signal acquisition | |
| CN111880123B (en) | Method for detecting frequency response signal of transformer winding resisting power frequency magnetic saturation | |
| CN205920148U (en) | High frequency current sensor for measurement of partial discharge | |
| CN104849606A (en) | Leakage current sensor | |
| CN212646872U (en) | Differential high-frequency current sensor | |
| CN109521264B (en) | Digital zero sequence current transformer for pole switch | |
| CN105785095A (en) | Constant-amplitude DC pulse signal measurement circuit and degaussing method thereof | |
| CN206311657U (en) | A kind of Rogowski coil transient current sensor | |
| CN219800651U (en) | Current transformer | |
| CN207798899U (en) | A kind of current sensor and monitoring system | |
| CN206132914U (en) | High frequency current sensor | |
| CN115097188A (en) | Large-caliber AC/DC current sensor based on zero magnetic flux principle | |
| CN108414798A (en) | A kind of current sensor, monitoring system and monitoring method | |
| CN201053988Y (en) | Highly antijamming AC current/ magnetic field sensor | |
| CN209821271U (en) | Multipurpose current transformer capable of being provided with Rogowski coil | |
| CN219039203U (en) | Anti-electromagnetic interference rogowski coil current sensor | |
| CN112034231B (en) | High-frequency current sensor based on frequency-dependent integral resistor | |
| CN218122079U (en) | Large-caliber alternating current and direct current sensor based on zero magnetic flux principle | |
| CN216310107U (en) | Digital quantity Hall current sensor and sensor debugging circuit | |
| CN215770827U (en) | Protection and metering integrated current transformer |
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 |