CN207097621U - A kind of retractable current transformer using grinding tooth shape open core - Google Patents

A kind of retractable current transformer using grinding tooth shape open core Download PDF

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Publication number
CN207097621U
CN207097621U CN201720933054.2U CN201720933054U CN207097621U CN 207097621 U CN207097621 U CN 207097621U CN 201720933054 U CN201720933054 U CN 201720933054U CN 207097621 U CN207097621 U CN 207097621U
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China
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iron core
grinding tooth
tooth shape
core
semicircular ring
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杨爱超
朱亮
李敏
谢三军
刘见
靳绍平
张春强
吴宇
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State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Jiangxi Electric Power Co Ltd
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State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Jiangxi Electric Power Co Ltd
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Abstract

It the utility model is related to a kind of retractable current transformer using grinding tooth shape open core, including grinding tooth shape open core, grinding tooth shape open core includes the grinding tooth shape open core main body being made up of iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II, iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II are engaged by grinding tooth shape opening I and grinding tooth shape opening II, winding I and winding II are respectively with iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II, winding I and winding II are around to identical, equal turn numbers, it is electrically in parallel, grinding tooth shape open core is fixed by skeleton, electric wire adaptive fixing device is set on the inside of grinding tooth shape open core, magnetic masking layer and shell are set on the outside of skeleton.The utility model, for the electric wire of different line footpaths, reduces the error that installation site deviation is brought, realizes the raising of accuracy of measurement on the premise of larger range of dynamic measurement is ensured.

Description

A kind of retractable current transformer using grinding tooth shape open core
Technical field
The utility model belongs to current measurement, field of sensing technologies, and in particular to using opening for grinding tooth shape open core Close current transformer design and the error method for reducing for its installation site deviation, for portable high-accuracy current measurement, Monitoring etc..
Background technology
Current measurement techniques are safe operation of electric network and the accurate important guarantee of electric energy metrical, while for line loss examination and instead Stealing detection provides important technical support.In power system, conventional current measure device is electromagnetic current transducer (abbreviation CT), it has high precision because having used closure high magnetic permeability iron core, but iron core-closed in high current or straight Flow and magnetic saturation easily occurs under current conditions, so as to cause relay fail or malfunction and electric energy metrical seriously overproof, and close iron Core installation inconvenience, it is difficult to dismantle, is not easy to safeguard.Thus, retractable CT is replaced iron core-closed using opening shaped iron core, on the one hand Iron core magnetic conductivity is reduced by iron core opening to improve the dynamic range of measurement, it is on the other hand real by retractable structure design Now install, safeguard, the facility of dismounting.However, when iron core opening is larger, magnetic resistance is too big in magnetic circuit, causes magnetic conductivity too low, electric current The precision of measurement is too low and does not reach the accuracy requirement in national standard GB1208-2006 on protecting, measuring;Therefore, CT is closed Shi Tiexin opening sizes must very little just can guarantee that CT while meet the requirement of accuracy of measurement and range of dynamic measurement.Currently may be used Folding CT commonly uses rectangular-shaped open core, and the depth of parallelism for the both ends of the surface that are on the one hand open requires high, and the bad both ends of the surface of the depth of parallelism exist Iron core easily forms larger opening when closing, and substantially reduces accuracy of measurement;Another aspect iron core opening uses machining (such as Cutting etc.) and flow harden layer is formed, the remanent magnetism of iron core is added, reduces magnetic conductivity, so as to cause under accuracy of measurement The reduction of drop and range of dynamic measurement.In addition, it can only often ensure that single size electric wire is fixed on during current retractable CT installations The center of iron core, and can produce measurement error during electric wire deviation core center.
Thus, the bad iron core open end depth of parallelism, flow harden layer, installation site deviation how are effectively reduced to measurement Adverse effect, be the problem urgently broken through.
Utility model content
Above-mentioned condition based on prior art, the utility model disclose a kind of retractable electricity using grinding tooth shape open core Current transformer and the error method for reducing for installation site deviation, on the premise of larger range of dynamic measurement is ensured, for The electric wire of different line footpaths, reduce the error that installation site deviation is brought, realize the raising of accuracy of measurement.
The utility model is realized by following technical proposals.
A kind of retractable current transformer using grinding tooth shape open core, including grinding tooth shape open core, grinding tooth shape are opened Mouth iron core includes the grinding tooth shape opening being made up of iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II Iron core main body, iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II are by grinding tooth shape opening I and nibble Dentation opening II engages, be respectively with iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II around Group I and winding II, winding I and winding II are around to identical, equal turn numbers, electrically in parallel.
As optimal technical scheme, grinding tooth shape open core main body uses the microcrystallizing alloy laminated stack of high magnetic permeability, symmetrically Property cuts out the semicircular ring iron core of two pieces of grinding tooth shape openings, so as to form iron core high magnetic permeability semicircular ring iron core I and the high magnetic of iron core Conductance semicircular ring iron core II, grinding tooth shape opening I and grinding tooth shape opening II.
As optimal technical scheme, iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II Grinding tooth shape opening I with grinding tooth shape opening II by being connected respectively by iron core fastener.
As optimal technical scheme, iron core fastener is made up of housing accessory I and housing accessory II, bolt, nut.Outside Shell annex I is fixed together with iron core high magnetic permeability semicircular ring iron core I, housing accessory II and iron core high magnetic permeability semicircular ring iron core II is fixed together, and passes through screw bolt and nut connected with outer casing annex I and housing accessory II.Component materials are adopted in iron core fastener Use aluminium.Iron core fastener is used for secured core, ensures iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring The good engagement of iron core II.
As optimal technical scheme, in addition to skeleton, skeleton uses hard plastic material, and parcel grinding tooth shape open core is peripheral, Play a part of insulation, protection iron core.
As optimal technical scheme, in addition to magnetic masking layer, magnetic masking layer is in the outer layer of skeleton, utilizes magnetic material Magnetic screening effect effectively eliminates the measurement error that external magnetic field interference fringe comes.Magnetic masking layer material uses permalloy.
As optimal technical scheme, in addition to shell, shell uses poured with epoxy resin, is arranged on current transformer most Outer layer, for protective current transformer to be overall simultaneously on physically and electrically.
As optimal technical scheme, in addition to the adaptive fixing device of electric wire, the adaptive fixing device of electric wire is using some Brute spring is combined, and is arranged on the inner side of grinding tooth shape open core, and the centre deviation of electric wire, is fitted when reducing current transformer installation Occasion for a variety of line footpath electric wires.
As optimal technical scheme, if the adaptive fixing device of the electric wire by scalable housing A, scalable housing B and Dry strength spring forms, some brute springs of installation in scalable housing A, some brute springs of installation in scalable housing B, can Telescopic shell A, scalable housing B surround the scalable casing center to be formed and leave the wire hole that supply lines passes through, strength bullet The both ends of spring are located at scalable housing A or scalable housings B top and bottom respectively.
Technological core of the present utility model is mainly the Unique physical design and processing and manufacturing by iron core grinding tooth shape opening Process modification effectively improves the degree of accuracy of measurement, reduces the survey that the iron core open end depth of parallelism is bad, flow harden layer is brought Measure error.
First, the Unique physical design of iron core grinding tooth shape opening is considered, its basic functional principle is:When punching electric wire internal memory In electric current, alternation punching electric current produces magnetic field of volution around it, minimum along magnetic resistance according to magnetic circuit theorem, magnetic field magnetic line Iron core formed magnetic loop.When iron core has opening, the total magnetic resistance of iron circuit is equal to iron core magnetic resistance and increases a mouthful magnetic resistance, because Opening is usually air and the magnetic resistance that is open is very big, causes iron circuit magnetic resistance to be significantly greatly increased, and Effective permeability declines, but iron Core linear working range greatly increases, and the range of dynamic measurement of current transformer is expanded therewith.Because magnetic resistance and the magnetic line of force The length passed through is directly proportional, and the cross-sectional area with passing through and permeability are inversely proportional, so in order to ensure that measurement is accurate Degree, the A/F of iron core should be much smaller than core length.When iron core is using grinding tooth shape opening (selection triangle end face), root According to the law of refraction in magnetic field, the angle of incident end face normal is directly proportional to permeability, so the magnetic line of force incides from iron core Pass through opening almost along normal direction after open end, the magnetic circuit cross-sectional area that the magnetic line of force passes through is proportional to grinding tooth type end side The length of side.Therefore, compared with the rectangular aperture of same widths, cross section that the magnetic resistance of grinding tooth shape opening actually passes through by the magnetic line of force Area is bigger and smaller;So as to which grinding tooth shape open core Effective permeability is bigger, its current transformer accuracy of measurement is higher.This Outside, the processing depth of parallelism of rectangle iron core opening both ends of the surface is inconsistent and closure dislocation is easily caused the very big of A/F and magnetic resistance The increase of degree, and grinding tooth shape opening can ensure unidirectional grinding tooth border good contact by closing to adjust so that magnetic The increase very little of resistance, accuracy of measurement vary less.
Secondly, the process for machining and manufacturing of iron core grinding tooth shape opening is considered:The mode of conventionally employed machining causes cold-working The formation of hardened layer, the remanent magnetism of iron core is added, reduces magnetic conductivity, so as to cause the decline of accuracy of measurement and dynamic to measure The reduction of scope;The utility model efficiently avoid the generation of flow harden layer using Machining Technology with WEDM, from And it ensure that the degree of accuracy and the dynamic range of measurement.
The measurement error that wire center deviation is brought when being installed for CT, cut down using symmetric winding multiple process.Specifically Scheme is that two groups of symmetry coiling is around the winding to identical, equal turn numbers, electrically parallel connection on iron core, when electric wire deviation electric current is mutual During sensor center, magnetic flux produces difference in iron core, and two winding output currents are in the same direction but amplitude is variant;Pass through two winding parallels A total electric current output can be obtained, measurement error caused by so as to cut down the difference of two winding currents output, is finally disappeared The measurement error that installation deviation is brought is subtracted.On the other hand, in order to meet current transformer applicability during electric wire difference line footpath, The utility model devises the adaptive fixing device of electric wire, and the device is combined and scalable by the symmetrical brute spring of some identicals Housing is formed.The resting length design of spring meets less electric wire line footpath.When electric wire line footpath changes, brute spring is urged Contract and produce reverse reverting power;Because each pair spring is is symmetrically installed two-by-two, therefore reverse reverting power caused by them is in electric current Transformer center is just offset, and so as to ensure that electric wire is in the center of current transformer to greatest extent, reduces position The measurement error that deviation is brought.
In a kind of embodiment of the utility model, iron core opening shape can be selected else as isosceles trapezoid, circular arc etc..
In a kind of embodiment of the utility model, core configuration can be selected else as straight-flanked ring etc..
In a kind of embodiment of the utility model, core material can be selected else as non-crystaline amorphous metal, permalloy etc..
In a kind of embodiment of the utility model, framework material can be selected else as aluminium, copper etc..
In a kind of embodiment of the utility model, winding quantity can be selected else as four groups, eight groups etc..
The characteristics of the utility model and advantage are:
(1) iron core uses grinding tooth shape opening, reduces opening magnetic resistance, improves iron core Effective permeability;Work as open end When the depth of parallelism is bad, be open magnetic resistance change rate unobvious.With using compared with rectangular aperture iron core current transformer, proposition it is retractable Current transformer has higher accuracy of measurement and more preferable faces parallel adaptivity.
(2) iron core opening processing uses Wire EDM technique, avoids because the cold-working that tradition machinery is processed and generates is hard Change accuracy of measurement and dynamic range decline problem that layer is brought, ensure the not processed adverse effect of accuracy of measurement.
(3) it is electrically in parallel using multigroup symmetric winding, effectively cut down the survey that current transformer installation site deviation is brought Measure error;Selectivity connects some windings, realizes the adjustability of current transformer turn ratio.
(4) the special adaptive fixing device of electric wire is used, meets current transformer for the powerful of different line footpath electric wires Applicability, while maximize the centre deviation of wire pair current transformer when reducing installation.
According to These characteristics, it can apply to high accuracy, the measurement of Larger Dynamic range current and conversion.
Brief description of the drawings
Fig. 1 is the utility model structure two-dimensional representation.
Fig. 2 is the utility model grinding tooth shape open core two-dimensional structure schematic diagram.
Fig. 3 is the utility model iron core fastener two-dimensional structure schematic diagram.
Fig. 4 is the adaptive fixing device two-dimensional structure schematic diagram of the utility model electric wire.
Embodiment
The utility model is further clarified below in conjunction with the accompanying drawings.
As shown in figure 1, using the retractable current transformer of grinding tooth shape open core mainly by grinding tooth in the utility model The adaptive fixing device 6 of shape open core 1, skeleton 2, magnetic masking layer 3, shell 4, iron core fastener 5, electric wire forms.Such as Fig. 2 Shown, grinding tooth shape open core 1 is included by the 1-1 of iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core The grinding tooth shape open core main body of II 1-2 compositions, the 1-1 of iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring The 1-2 of iron core II is engaged by the 1-3 of grinding tooth shape opening I and the 1-4 of grinding tooth shape opening II, the 1-1 of iron core high magnetic permeability semicircular ring iron core I and The 1-5 of winding I and winding II 1-6, the 1-5 of winding I and the 1-6 of winding II are respectively with the 1-2 of iron core high magnetic permeability semicircular ring iron core II Around to identical, equal turn numbers, electrically in parallel;
Grinding tooth shape open core main body uses the microcrystallizing alloy laminated stack of high magnetic permeability, and symmetry cuts out two pieces of grinding tooth shapes The semicircular ring iron core of opening, so as to form the 1-1 of iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II 1-2, the 1-3 of grinding tooth shape opening I and grinding tooth shape opening II 1-4, the 1-5 of winding I and the 1-6 of winding II be used for first and second current transformation and Position deviation compensates.The 1-5 of the winding I and 1-6 of winding II uses enamel covered wire coiling.
The 1-1 of iron core high magnetic permeability semicircular ring iron core I and the 1-2 of iron core high magnetic permeability semicircular ring iron core II grinding tooth shape opening I By being connected respectively by iron core fastener 5 at the 1-3 and 1-4 of grinding tooth shape opening II.As shown in figure 3, iron core fastener 5 is led To be made up of the 5-1 of housing accessory I and the 5-2 of housing accessory II, bolt 5-3, nut 5-4.The 5-1 of housing accessory I and the high magnetic conductance of iron core The 1-1 of rate semicircular ring iron core I is fixed together, and the 5-2 of the housing accessory II and 1-2 of iron core high magnetic permeability semicircular ring iron core II is fixed on one Rise, pass through bolt 5-3 and the 5-1 of the nut 5-4 connected with outer casing annex I and 5-2 of housing accessory II.Part material in iron core fastener 5 Material uses aluminium.
Skeleton 2 uses hard plastic material, the periphery of parcel grinding tooth shape open core 1, plays a part of insulation, protection iron core.Magnetic Screen layer 3 is in the outer layer of iron core protection insulating barrier (skeleton 2), and the external world is effectively eliminated using the magnetic screening effect of magnetic material The measurement error that magnetic interference is brought;Shell 4 uses poured with epoxy resin, outermost layer is molded over, for physically and electrically Protective current transformer is overall simultaneously;Iron core fastener 5 is used for secured core, ensures iron core high magnetic permeability semicircular ring iron core I 1-1 and the 1-2 of iron core high magnetic permeability semicircular ring iron core II good engagement;If the adaptive fixing device 6 of electric wire uses dry strength bullet Spring combines, and is arranged on the inner side of grinding tooth shape open core 1, and the centre deviation of electric wire, is applied to when reducing current transformer installation The occasion of a variety of line footpath electric wires.Skeleton 2, shell 4 use epoxide resin material, and the material of magnetic masking layer 3 uses permalloy.
As shown in figure 4, the adaptive fixing device 6 of electric wire is mainly by scalable housing A6-1, scalable housing B6-2 and strong Power spring A6-3, brute spring B6-4, brute spring C6-5, brute spring D6-6, brute spring E6-7, brute spring E6-8 groups Into installation brute spring D6-6, brute spring E6-7, brute spring E6-8, scalable housing B6-2 in scalable housing A6-1 Interior installation brute spring A6-3, brute spring B6-4, brute spring C6-5.Wherein, scalable housing A6-1, scalable housing B6-2 uses epoxide resin material, brute spring A6-3, brute spring B6-4, brute spring C6-5, brute spring D6-6, strong Power spring E6-7 material uses bronze wire Qsi-3.Scalable housing A6-1, scalable housing B6-2 surround stretching of being formed Contracting casing center leaves the wire hole that supply lines passes through, and brute spring both ends are located at scalable housing A6-1 or scalable shells respectively Body B6-2 top and bottom.
During practical set, when installing retractable current transformer, retractable current transformer is opened and is enclosed on electricity Above line, then iron core fastener 5 is tightened in aligned engagement end face, and now the adaptive fixing device 6 of electric wire passes through contained spring The reverse reverting power negative function of combination is automatically fixed on electric wire the center of retractable current transformer.When retractable electricity When current transformer carries out current measurement, alternating magnetic field caused by live wire and magnetic flux are converged wherein by grinding tooth shape open core 1, Grinding tooth shape opening designs the effective cross section area that the magnetic line of force is passed through and greatly increased, and so as to reduce the total magnetic resistance of magnetic circuit, carries The high current measurement degree of accuracy of the Effective permeability summation current transformer of grinding tooth shape open core 1.If grinding tooth shape opening both ends The face depth of parallelism misfits, then magnetic force self-gravitation caused by the inside of grinding tooth shape open core 1 can ensure that grinding tooth end face is same during measurement To the good contact on border, the magnetic resistance brought increase degree is misfitted so as to reduce the open end depth of parallelism to greatest extent, most The adverse effect to accuracy of measurement is eliminated eventually.Being broken down when the adaptive contained spring of fixing device 6 combination of electric wire can not be complete All risk insurance demonstrate,proves electric wire at the center of current transformer, the 1-5 of winding I and the 1-6 of winding II by be connected in parallel output current and Mode effectively cut down the measurement error that electric wire position deviation is brought.Therefore, using the retractable electricity of grinding tooth shape open core 1 Current transformer can apply to high accuracy, the measurement of Larger Dynamic range current and conversion.

Claims (8)

1. a kind of retractable current transformer using grinding tooth shape open core, including grinding tooth shape open core, it is characterized in that:Nibble Dentation open core includes the grinding tooth being made up of iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II Shape open core main body, iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II are opened by grinding tooth shape Mouth I and grinding tooth shape opening II engage, on iron core high magnetic permeability semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II respectively With winding I and winding II, winding I and winding II around to identical, equal turn numbers, it is electrically in parallel.
2. the retractable current transformer according to claim 1 using grinding tooth shape open core, it is characterized in that:Iron core is high Pass through at the grinding tooth shape opening I and grinding tooth shape opening II of magnetic conductivity semicircular ring iron core I and iron core high magnetic permeability semicircular ring iron core II Connected respectively by iron core fastener.
3. the retractable current transformer according to claim 2 using grinding tooth shape open core, it is characterized in that:Iron core is tight It is fixedly mounted with to put and is made up of housing accessory I and housing accessory II, bolt, nut;Housing accessory I and iron core high magnetic permeability semicircular ring iron core I is fixed together, and housing accessory II is fixed together with iron core high magnetic permeability semicircular ring iron core II, is connected by screw bolt and nut Housing accessory I and housing accessory II.
4. the retractable current transformer according to claim 1 using grinding tooth shape open core, it is characterized in that:Also include Skeleton, skeleton use hard plastic material, parcel grinding tooth shape open core periphery.
5. the retractable current transformer according to claim 1 using grinding tooth shape open core, it is characterized in that:Also include Magnetic masking layer, magnetic masking layer are in the outer layer of skeleton.
6. the retractable current transformer according to claim 1 using grinding tooth shape open core, it is characterized in that:Also include Shell, shell use poured with epoxy resin, are arranged on the outermost layer of current transformer.
7. the retractable current transformer according to claim 1 using grinding tooth shape open core, it is characterized in that:Also include The adaptive fixing device of electric wire, the adaptive fixing device of electric wire are combined using some brute springs, are arranged on grinding tooth shape opening iron The inner side of core.
8. the retractable current transformer according to claim 7 using grinding tooth shape open core, it is characterized in that:The electricity The adaptive fixing device of line is made up of scalable housing A, scalable housing B and some brute springs, is installed in scalable housing A Some brute springs, the interior some brute springs of installation of scalable housing B, scalable housing A, scalable housing B surround to be formed Scalable casing center leave the wire hole that supply lines passes through, the both ends of brute spring are respectively positioned at scalable housing A or can Telescopic shell B top and bottom.
CN201720933054.2U 2017-07-29 2017-07-29 A kind of retractable current transformer using grinding tooth shape open core Active CN207097621U (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107403683A (en) * 2017-07-29 2017-11-28 国网江西省电力公司电力科学研究院 A kind of retractable current transformer using grinding tooth shape open core
CN110620000A (en) * 2019-07-08 2019-12-27 河南平高电气股份有限公司 Voltage transformer and shielding case thereof
CN110767428A (en) * 2019-11-07 2020-02-07 安徽昭田电子科技有限公司 Magnetic core coil component and manufacturing method of magnetic core
WO2020244144A1 (en) * 2019-06-04 2020-12-10 北京航天常兴科技发展股份有限公司 Unit-type current transformer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107403683A (en) * 2017-07-29 2017-11-28 国网江西省电力公司电力科学研究院 A kind of retractable current transformer using grinding tooth shape open core
WO2020244144A1 (en) * 2019-06-04 2020-12-10 北京航天常兴科技发展股份有限公司 Unit-type current transformer
CN110620000A (en) * 2019-07-08 2019-12-27 河南平高电气股份有限公司 Voltage transformer and shielding case thereof
CN110767428A (en) * 2019-11-07 2020-02-07 安徽昭田电子科技有限公司 Magnetic core coil component and manufacturing method of magnetic core

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