CN203630167U - Electromagnetic interference-preventing device of clip-on ammeter - Google Patents
Electromagnetic interference-preventing device of clip-on ammeter Download PDFInfo
- Publication number
- CN203630167U CN203630167U CN201320821269.7U CN201320821269U CN203630167U CN 203630167 U CN203630167 U CN 203630167U CN 201320821269 U CN201320821269 U CN 201320821269U CN 203630167 U CN203630167 U CN 203630167U
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- CN
- China
- Prior art keywords
- amperemeter
- clamp
- clip
- ammeter
- electromagnetic interference
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- 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.)
- Expired - Lifetime
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- 239000002184 metal Substances 0.000 claims abstract description 35
- 229910052751 metal Inorganic materials 0.000 claims abstract description 35
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 21
- 238000001514 detection method Methods 0.000 abstract description 11
- 238000005259 measurement Methods 0.000 abstract description 4
- 238000012360 testing method Methods 0.000 description 10
- 230000005540 biological transmission Effects 0.000 description 5
- 230000005672 electromagnetic field Effects 0.000 description 4
- 230000001131 transforming effect Effects 0.000 description 3
- 230000004907 flux Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 239000002390 adhesive tape Substances 0.000 description 1
- 238000013142 basic testing Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000003032 molecular docking Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Images
Abstract
An electromagnetic interference-preventing device of a clip-on ammeter comprises a metal shielding cover capable of covering a jaw of the clip-on ammeter. The metal shielding cover comprises two half U-shaped hollow metal shell bodies which cover the jaw of the clip-on ammeter from two sides. A metal cap body used for covering the jaw of the clip-on ammeter from the top is arranged on the upsides of the two half U-shaped hollow metal shell bodies. The metal cap body is provided with a ground wire connecting groove used for guaranteeing reliable grounding of the metal shielding cover. The joint between the two half U-shaped hollow metal shell bodies is provided with a rectangular gap for outlet of a transformer core grounding down lead. The electromagnetic interference-preventing device is simple in structure and convenient and reliable to use. The device can improve the electromagnetic interference-preventing capability of the clip-on ammeter effectively, thereby enabling accurate measurement of the ground connection current value of the core, improving the live detection level and guaranteeing the safe and stable operation of an electric power system.
Description
Technical field
The utility model relates to a kind of anti-electromagnetic interference device of clamp on amperemeter, belong to power measurement technical field.
Background technology
Along with take the continuous propelling as main power transmission and transformation equipment state overhauling work with electro-detection, increasing fixed and portable charged detection technique is applied to the state-detection of power transmission and transforming equipment, and the detection that do not have a power failure becomes possibility day by day.The state estimation Data Source of electrical network power transmission and transforming equipment more and more lays particular emphasis on the test findings with electro-detection, and therefore, the accuracy with electro-detection data is particularly important.Operating iron core should be in single-point grounding state, and iron core induces static charge in alternating electric field, and down conductor will pass through alternating current.But, iron core waits iron core may have multipoint earthing because mounting process is bad, two and above earth point formation loop, and with leakage flux interlinkage, between earth point, there is the circulation that numerical value is higher, larger circulation makes iron core heating, iron core heating causes between lamination insulation degradation or Gas in Oil of Transformer is separated out, the scaling loss that insulate under high temperature, a large amount of gas evolutions, cause gas action when serious.
Can directly reflect the malfunction of transformer by measuring transformer iron core grounding current---whether there is multipoint earthing of iron core.Electrical network " power transmission and transformation equipment state overhauling testing regulations " regulation, iron core grounding current is Power transformer diagnosis test, its measured value is answered <100mA.2000 to 2012,9070 of Jiaxing electrical network power transmission and transforming equipment defect records, related to 841 of main transformers, and 1 of relevant iron core grounding current, for Jia Bei becomes iron core grounding current severe overweight.In electric system, conventionally adopt clamp on amperemeter to carry out iron core grounding current band electro-detection.
Clamp on amperemeter principle of work mainly contains two kinds, i.e. ordinary electric current mutual-inductor type and Hall element type.The former is combined by current transformer and reometer, and its principle is as Fig. 1.The primary winding that just becomes current transformer through circuit-under-test wire unshakable in one's determination wherein induces electric current in secondary coil by reometer.Thereby make the reometer that secondary coil is connected have indication, measure the electric current of test line.Pincerlike meter common accurate is not high, is generally 2.5～5 grades.Hall element type clamp on amperemeter is also magnetic balancing current sensor, as Fig. 2.The magnetic field that the magnetic field that primary current IN produces in magnetism gathering rings place produces by a secondary current compensates, and its offset current IM reflects primary current IN accurately, thereby makes hall device in detecting the duty of zero magnetic flux.
Due to on-the-spot electromagnetic environment complexity, clamp on amperemeter is affected by electromagnetic interference, detects numerical value and has jump phenomena, extremely unstable, affects test accuracy.
According to magnetic field Biot-Savart law:
, in the situation that other factors is constant, square being inversely proportional to of the magnetic field intensity of certain point and distance.Therefore, while measuring iron core grounding current, clamp on amperemeter is subject to transformer magnetic field and strongly disturbs.Therefore, under the prerequisite of normative testing, improving accuracy in detection just must manage to make external electromagnetic field interference to be reduced to zone of reasonableness to the impact of clamp on amperemeter test accuracy.
Improve measuring accuracy and can pass through the more excellent product of buying antijamming capability, but cost is high, and this series products does not all provide the test report under strong electromagnetic interference environment.
Summary of the invention
The purpose of this utility model is to overcome the deficiency that prior art exists, and provide a kind of simple in structure, easy to use, reliable, can effectively improve clamp on amperemeter anti-electromagnetic interference capability, with Measurement accuracy iron core grounding current value, elevator belt electro-detection level, the anti-electromagnetic interference device of the clamp on amperemeter of assurance power system safety and stability operation.
The purpose of this utility model completes by following technical solution, the anti-electromagnetic interference device of described clamp on amperemeter, it comprises that one can cover the metallic shield case of clamp on amperemeter jaw, described metallic shield case comprises that two halves can cover from both sides the U-shaped hollow metal housing of clamp on amperemeter jaw, on described two halves U-shaped hollow metal housing, dispose one and cover the metal cap body of clamp on amperemeter jaw from above, and on described metal cap body, be provided with the ground wire link slot for guaranteeing metal screen case reliable ground.
Junction between described two halves U-shaped hollow metal housing is provided with a rectangle space picking out for transformer iron core grounding down lead.
The utility model belongs to the improvement to prior art, and it has simple in structure, easy to use, reliable, can effectively improve clamp on amperemeter anti-electromagnetic interference capability, with Measurement accuracy iron core grounding current value, elevator belt electro-detection level, guarantees the features such as power system safety and stability operation.
Accompanying drawing explanation
Fig. 1 is common current mutual inductive type clamp on amperemeter principle schematic described in prior art.
Fig. 2 is Hall element type clamp on amperemeter principle schematic described in prior art.
Fig. 3 is the structural representation of metallic shield case described in the utility model.
Fig. 4 is metallic shield structural representation described in the utility model.
Embodiment
Below in conjunction with accompanying drawing, the utility model is done to detailed introduction: Fig. 3, shown in 4, the anti-electromagnetic interference device of clamp on amperemeter described in the utility model, it comprises that one can cover the metallic shield case 2 of clamp on amperemeter jaw 1, described metallic shield case 2 comprises that two halves can cover from both sides the U-shaped hollow metal housing 3 of clamp on amperemeter jaw 1, on described two halves U-shaped hollow metal housing 3, dispose a metal cap body 4 that covers clamp on amperemeter jaw 1 from above, and on described metal cap body 4, be provided with the ground wire link slot for guaranteeing metal screen case reliable ground.
Junction between two halves U-shaped hollow metal housing 3 described in the utility model is respectively provided with the rectangular recess of a positioned opposite, and has formed the rectangle space 5 picking out for transformer iron core grounding down lead after the docking of two rectangular recess.
Embodiment: the utility model is through the analysis of clamp on amperemeter basic test principle is drawn, employing metal material to external world electromagnetic field shields, and the electromagnetic field flow through clamp on amperemeter magnetic core and the Hall element that only allow primary coil to produce could manyly farthest reduce external electromagnetic field and disturb.Therefore, the utility model designs and produces metallic shield case and realizes reaching shield effectiveness, considers transformer iron core grounding down lead sheet metal size, therefore long 100mm is left in coated metal screen layer middle part, the space of wide 15mm, sees shown in Fig. 3,4.
Claims (2)
1. the anti-electromagnetic interference device of a clamp on amperemeter, it comprises that one can cover the metallic shield case of clamp on amperemeter jaw, it is characterized in that described metallic shield case comprises that two halves can cover from both sides the U-shaped hollow metal housing of clamp on amperemeter jaw, on described two halves U-shaped hollow metal housing, dispose one and cover the metal cap body of clamp on amperemeter jaw from above, and on described metal cap body, be provided with the ground wire link slot for guaranteeing metal screen case reliable ground.
2. the anti-electromagnetic interference device of clamp on amperemeter according to claim 1, is characterized in that the junction between described two halves U-shaped hollow metal housing is provided with a rectangle space picking out for transformer iron core grounding down lead.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320821269.7U CN203630167U (en) | 2013-12-13 | 2013-12-13 | Electromagnetic interference-preventing device of clip-on ammeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320821269.7U CN203630167U (en) | 2013-12-13 | 2013-12-13 | Electromagnetic interference-preventing device of clip-on ammeter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203630167U true CN203630167U (en) | 2014-06-04 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320821269.7U Expired - Lifetime CN203630167U (en) | 2013-12-13 | 2013-12-13 | Electromagnetic interference-preventing device of clip-on ammeter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203630167U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103698559A (en) * | 2013-12-13 | 2014-04-02 | 国家电网公司 | Electromagnetic interference prevention device for tong type ammeter |
-
2013
- 2013-12-13 CN CN201320821269.7U patent/CN203630167U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103698559A (en) * | 2013-12-13 | 2014-04-02 | 国家电网公司 | Electromagnetic interference prevention device for tong type ammeter |
| CN103698559B (en) * | 2013-12-13 | 2016-05-04 | 国家电网公司 | A kind of anti-electromagnetic interference device of clamp on amperemeter |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20140604 Effective date of abandoning: 20160504 |
|
| C25 | Abandonment of patent right or utility model to avoid double patenting |