CN205898871U - Current transformer who opens a way is not afraid of to secondary side - Google Patents
Current transformer who opens a way is not afraid of to secondary side Download PDFInfo
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- CN205898871U CN205898871U CN201620877455.6U CN201620877455U CN205898871U CN 205898871 U CN205898871 U CN 205898871U CN 201620877455 U CN201620877455 U CN 201620877455U CN 205898871 U CN205898871 U CN 205898871U
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Abstract
The utility model discloses a current transformer who opens a way is not afraid of to secondary side, generating line side current transformer and the conversion current transformer rather than electric connection including at least one punching, generating line side current transformer is used for responding to bus current, generating line side current transformer's output electric connection to the primary wiring end of changing current transformer, conversion current transformer's output is used for being connected to the strapping table meter, conversion current transformer sets up in one side of generating line side current transformer, and conversion current transformer and generating line side current transformer realize mechanical connection and electric isolation through the resin of casting among them. The utility model discloses be equivalent to for generating line side current transformer's output regularly and connect one to prevent its load of opening a way, the harm that the secondary side opened a way and cause can fundamentally prevents and stops effectively, has avoided the secondary to open a way and has caused the problem of product explosion, safe and reliable ensures personal equipment safety.
Description
Technical field
This utility model is related to the current transformer that a kind of secondary side is not afraid of open circuit.
Background technology
In each link of power system, including generating, power transformation, transmission of electricity, distribution and electricity consumption, it is required for circuit is surveyed
Amount, protection and control (hereinafter referred to as observing and controlling).But size of current great disparity in circuit, have to tens of thousands of Andu from several peace, these electricity
Stream needs to be converted to the unified electric current of comparison, and in addition the voltage on circuit is typically all higher, and such as direct observing and controlling is abnormally dangerous
's.The effect of current transformer (current transformer, abbreviation ct) is primary current larger for numerical value can be passed through
Certain no-load voltage ratio is converted to the less secondary current of numerical value, for the purposes such as carrying out protecting, measuring.The electricity being 400/5 as no-load voltage ratio
Current transformer, can be changed into the actual electric current for 400a the electric current of 5a.In addition to the effect playing current transformation, also act as electricity
Gas buffer action.
Current transformer is made up of the iron core closing and winding.Its first winding number of turn is little, in practice often only
There is a circle, that is, punching and mistake, in needing the circuit of electric current of measurement, therefore it often has whole electric current streams of circuit to string
Cross, secondary side turn ratio is more, be serially connected in the equipment such as measuring instrumentss and protective loop.
In normal work, its secondary circuit is closure to current transformer all the time, because being connected on current transformer pair
The impedance very little of the instrument coil on coil, is equivalent to and runs under secondary coil short-circuit condition.Electricity on transformer secondary coil terminal
Pressure only has several volts.Thus the magnetic flux in iron core is very little.Although primary coil magnetomotive force can reach hundreds of peace or thousands of ampere-turn
Or it is bigger.Operating secondary loop of mutual inductor does not allow to open a way.Otherwise high voltage can be produced at the two ends of open circuit to jeopardize
Personal equipment safety, or so that current transformer is generated heat.
During normal operation, due to the impedance very little of Secondary Winding, magnetomotive force produced by primary current is most of secondary
The magnetomotive force that electric current produces is compensated, total magnetic flux density less, the electromotive force of Secondary Winding sensing also less, typically not over
Tens volts.When secondary circuit is opened a way, impedance infinitely increases, secondary current vanishing, the also vanishing of Secondary Winding magnetomotive force, and
Once winding current does not diminish with second open circuit again, loses the magnetomotive compensating action of Secondary Winding, a magnetomotive force is very
Greatly, it is completely used for excitation, resultant flux increases suddenly a lot of times, makes the magnetic circuit height saturation of iron core, now primary current
All become exciting current, Secondary Winding produces very high electromotive force, its peak value even volts up to ten thousand, prestige up to several kilovolts
Coerce personal safety or cause instrument, protection device, transformer secondary insulating to damage.
Further, since the height saturation of magnetic circuit, magnetic induction is made suddenly to increase, in iron core magnetic hysteresis and eddy-current loss is drastically
Rise, iron core can be caused overheated or even burn current transformer.So in running when needing maintenance, verification secondary meter, must
First by secondary winding in current transformer or loop short circuit, then disassembling section must be carried out, secondary loop of mutual inductor can not be installed
Fuse.Solve the existing protective measure of Current Transformer Secondary side output loop open circuit, substantially have following several:
The first, adopt the pressure cell such as varistor, gas-discharge tube, when Current Transformer Secondary side, output loop is opened
Lu Shi, once open-circuit voltage reaches the operation voltage of pressure-sensitive device, pressure-sensitive device turns on, and makes output voltage control in pressure-sensitive electricity
Pressure.But, conducting voltage height (more than more than ten volts) of pressure-sensitive device, lasting conveyance capacity are little, and the electric current using on circuit is mutual
Sensor, the pressure-sensitive device that its rated output is substantially under 5a, prior art is only possible to continue in the range of millisecond (ms) level
The so big electric current of excessively stream, and current transformer output loop is once opened a way, the persistent period is unlikely to be ms level.Therefore, press
Sensing device is protected it is easy to puncturing and forming permanent conducting it is necessary to change device could recover transformer output loop
Normal work, or directly burn and do not have protective effect.
Second, using Current Transformer Secondary side output loop open circuit when, once open-circuit voltage reaches certain value, by one
The individual coil being attempted by two outfans attracts spring tripping mechanism, and tripping mechanism action makes contact short, thus reach protection making
With.Because coil is attempted by two outfans of transformer, during transformer normal work, coil itself inevitably will flow through one
The electric current of partial mutual inductance device secondary side, this portion of electrical current does not flow through the testing equipment that should need to flow through, thus setting to detection
Standby bring obvious error；Second, mechanical mechanism is slow in one's movements, and during transformer output open circuit, voltage rises quickly (us level),
Many times also do not play a protective role, and outside accident already occurs.
The third, in outfan, one relay is installed, the contact portion of relay, at the two ends of outfan, fills by manipulation
Put control relay to open and close, the protection of the output loop of current transformer is realized with this.Need manual intervention completely, for
Unexpected open circuit, does not have protective effect at all.
Chinese Patent Application No. 201210196247.6, discloses a kind of current transformer over-voltage protection method and device,
This utility model is related to a kind of current transformer over-voltage protection method and device, and methods described is collection Current Transformer Secondary side
Current signal；The current signal collecting is converted to voltage signal contrasted with protection value set in advance, judges institute
State whether Current Transformer Secondary side is open circuit；When the voltage signal after conversion is more than described protection value set in advance, short
Connect described secondary loop of mutual inductor, when the voltage signal after conversion is not more than described protection value set in advance, recover
The normal connection status of described current transformer；Described device includes sampling unit, main control unit, pressure limited protection circuit and open circuit
Protection act element, the lead-out terminal of described open-circuit-protection action element be connected to described current transformer lead-out terminal it
Between.This utility model is controlled using aptitude manner, complete open-circuit-protection using mechanical switch simultaneously, it is to avoid prior art
The impact that the heating of lower electronic devices and components causes to whole circuit.
This utility model and above scheme and its prior art, are all the second open circuits afterwards for current transformer
Make remedial measure, fail to tackle the problem at its root.
Utility model content
The technical problems to be solved in the utility model is: provides a kind of secondary side not to be afraid of the current transformer of open circuit, not only
Ensure that the precision of measurement, and, can fundamentally be effectively prevented the various harm that the open circuit of secondary side causes.
The technical scheme of the technical problems to be solved in the utility model is:
Secondary side is not afraid of the current transformer of open circuit, the bus bar side current transformer including at least one punching and one
The switching current transformer being electrically connected；Described bus bar side current transformer is in order to sense bus current；Bus bar side electric current
The outfan of transformer is electrically connected to the primary coil terminals of switching current transformer；Described switching current transformer defeated
Go out to connect to measurement meter, described switching current transformer is arranged at the side of bus bar side current transformer, switching current
Transformer and bus bar side current transformer are realized being mechanically connected and electrical isolation by the resin cast therebetween.
Preferably, described bus bar side current transformer is two, and described switching current transformer is two, for biphase mother
The measurement of line current, the primary coil that the outfan of bus bar side current transformer is respectively and electrically connected to switching current transformer connects
Line end.
Preferably, described bus bar side current transformer is three, and described switching current transformer is three, female for three-phase
The measurement of line current, the primary coil that the outfan of bus bar side current transformer is respectively and electrically connected to switching current transformer connects
Line end.
Excellent effect of the present utility model:
Secondary side of the present utility model is not afraid of the current transformer of open circuit, is provided with to sense bus current bus bar side electric current
Transformer, and the rear side in bus bar side current transformer connect the primary coil of a switching current transformer, switching current is mutual
The resistance of the primary coil of sensor is less, is equivalent to the output to bus bar side current transformer and regularly and connects one and prevent it from opening
The load on road, therefore can momently guarantee that the output of bus bar side current transformer is not in high-tension situation, energy
Enough fundamentally it is effectively prevented and prevents the harm that secondary side open circuit causes, it is to avoid second open circuit causes asking of product blast
Topic, safe and reliable it is ensured that personal equipment safety.
Brief description
Accompanying drawing described herein further understands to of the present utility model in order to provide, and constitutes this utility model application
A part, schematic description and description of the present utility model is used for explaining this utility model, does not constitute new to this practicality
The improper restriction of type.
With reference to the accompanying drawings and examples this utility model is further illustrated.
Accompanying drawing 1 is a kind of electrical connection schematic diagram of embodiment of this utility model；
Accompanying drawing 2 is a kind of structural representation of embodiment of this utility model.
In figure:
1st, bus bar side current transformer,
2nd, switching current transformer,
3rd, current bus bar,
4th, resin,
5th, bus bar side current transformer center cavity,
6th, bus bar side current transformer lifting nut,
7th, lead,
8th, switching current transformer lifting nut.
Specific embodiment
Below by way of particular specific embodiment, technology contents of the present utility model are described, those skilled in the art can be by
The content that this specification discloses understands further advantage of the present utility model and effect easily.This utility model also can be by other
Different specific embodiments is implemented or is applied, the every details in this specification also can based on different viewpoints and application,
Carrying out various modification and change without prejudice under spirit of the present utility model.
Below in conjunction with accompanying drawing, this utility model is described in further detail.
Furthermore, it is necessary to explanation, unless stated otherwise or point out, otherwise the term in description " first ", " the
Two ", " the 3rd ", " a phase ", " b phase ", " c phase " etc. describe each assembly being used only in differentiation description, element, step, only
Merely to convenience of description etc., rather than for representing the logical relation between each assembly, element, step or order pass
System etc., is not specifically particularly to specify.
In order to solve from source, the various adverse consequencess that Current Transformer Secondary side open circuit brings, of the present utility model two
The current transformer of open circuit is not afraid of in secondary side, is made that creative conceptual design, referring to Fig. 1, design of the present utility model
The switching current transformer 2 being electrically connected including bus bar side current transformer 1 and one of at least one punching；Punching
The bus bar side current transformer 1 of formula carries out coiling using routine techniquess, and described bus bar side current transformer 1 is in order to sense bus electricity
Stream.Referring to Fig. 1, bus bar side current transformer center cavity 5 passes through current bus bar 3, and described current bus bar 3 is serially connected with main line
In.Described bus bar side current transformer 1 passes through lead 7 and switching current transformer 2 connects.
The described switching current transformer being electrically connected by bus bar side current transformer 1 and of a punching
The secondary side of 2 compositions is not afraid of the current transformer of open circuit, is only used for the measurement of a phase bus current.
Based on above-mentioned thought, for expanded application, described bus bar side current transformer is two, described switching current
Transformer is two, and the outfan of bus bar side current transformer is respectively with switching current transformer input and connect, so composition
Secondary side be not afraid of the current transformer of open circuit and can be used for the measurement of biphase bus current.
Further, if described bus bar side current transformer is three, described switching current transformer is three, bus bar side
Respectively with switching current transformer input and connect, the secondary side of so composition is not afraid of the electricity of open circuit to the outfan of current transformer
Current transformer can be used for the measurement of three-phase bus electric current.
Switching current transformer 2 is the current transformer with identical no-load voltage ratio or different no-load voltage ratio, conventional, switching current is mutual
Sensor is 5a/5a type.In order to by measuring accuracy, switching current transformer 2 can use the high-precision current of routine techniquess mutual
Sensor.The current transformer of 0.1 class precision for example can be adopted.
Conventional, high precision current transformer is made up of first winding, Secondary Winding.5/5 type or 1/1 type electricity can be carried out
Flow ratio self-correcting.
Precision current transformer is unshakable in one's determination to adopt high permeability soft magnetic material roll-forming, high temperature protection heat treatment, one or two times
Coil high-strength polyester enamel-covered wire, and with absorbance very low insulation material coiling, coil surface recoat is processed, and lead end is led
The enough contacts area of electric pole are it is ensured that stable performance is safe and reliable to operation.It is applied to research unit, test chamber, factory, the magnitude of current
Value transmission, precision current measures, standard mutual inductor.
In order to prevent bus bar side current transformer 1 outfan accident open circuit, described bus bar side current transformer 1 defeated
Go out the primary coil terminals that end is electrically connected to switching current transformer 2；The output of described switching current transformer 2 is in order to even
It is connected to measurement meter.The resistance of the primary coil of described switching current transformer 2 is less, is attempted by bus bar side current transformer 1
Outfan, be equivalent to the outfan to bus bar side current transformer 1 and connect the load of a fixation, and then, also just from basic
On solve the problems, such as that the outfan of bus bar side current transformer 1 is surprisingly opened a way.
In terms of installation and internal placement, described switching current transformer 2 is arranged at the one of bus bar side current transformer 1
Side, switching current transformer 2 and bus bar side current transformer 1 pass through the resin 4 cast therebetween realize being mechanically connected and electrically every
From.The high intensity of resin 4 and excellent electrical specifications are it is achieved that the machine of bus bar side current transformer 1 and switching current transformer 2
Tool connects and electrical isolation.
The theory based on above-mentioned innovation for this utility model, and then also disclose that a kind of secondary side is not afraid of the Current Mutual Inductance of open circuit
The manufacture method of device, comprises the steps；
1st step: conventional, the punching bus bar side current transformer 1 of coiling phase strain ratio；
2nd step: conventional, coiling switching current transformer 2；
3rd step: the primary coil that the output electric property of bus bar side current transformer 1 is connected to switching current transformer 2 connects
Line end；
4th step: bus bar side current transformer and switching current transformer are kept at a certain distance away and is positioned in casting die,
Conventional, carry out vacuum stirring and the casting of resin, and be subsequently dried；
5th step: the demoulding.
The switching current transformer being electrically connected with bus bar side current transformer 1 and one of a punching above
The secondary sides of 2 compositions have carried out the description of manufacture method as a example not being afraid of the current transformer of open circuit, for having two or three
The electric current that the secondary side of bus bar side current transformer 1 and switching current transformer 2 composition being electrically connected is not afraid of open circuit is mutual
Sensor, can be in this, as reference.
Preferably, in described step 2, described switching current transformer is 5a/5a type.
Preferably, in described step 4, described switching current transformer 2 is arranged at the lower section of bus bar side current transformer 1.
Referring to Fig. 2, bus bar side current transformer lifting nut 6 is provided with bus bar side current transformer 1, in switching current
Transformer 2 is provided with switching current transformer lifting nut 8, and it is used for the installation positioning in mutual-inductor mould.
Although this patent is explained with reference to preferred embodiment and accompanying drawing, but above-mentioned explanation should be regarded as illustrative
And non-limiting, change and modification that those skilled in the art is made according to spirit of the present utility model, this patent all should be belonged to
Protection domain.
Claims (3)
1. secondary side be not afraid of open circuit current transformer it is characterised in that:
Bus bar side current transformer including at least one punching and a switching current transformer being electrically connected；
Described bus bar side current transformer is in order to sense bus current；
The outfan of bus bar side current transformer is electrically connected to the primary coil terminals of switching current transformer；
The output of described switching current transformer in order to connect to measurement meter,
Described switching current transformer is arranged at the side of bus bar side current transformer, switching current transformer and bus bar side electric current
The resin that transformer passes through to cast therebetween is realized being mechanically connected and electrical isolation.
2. a kind of secondary side according to claim 1 be not afraid of open circuit current transformer it is characterised in that:
Described bus bar side current transformer is two, and described switching current transformer is two, for the survey of biphase bus current
Amount, the outfan of bus bar side current transformer is respectively and electrically connected to the primary coil terminals of switching current transformer.
3. a kind of secondary side according to claim 1 be not afraid of open circuit current transformer it is characterised in that:
Described bus bar side current transformer is three, and described switching current transformer is three, for the survey of three-phase bus electric current
Amount, the outfan of bus bar side current transformer is respectively and electrically connected to the primary coil terminals of switching current transformer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620877455.6U CN205898871U (en) | 2016-08-12 | 2016-08-12 | Current transformer who opens a way is not afraid of to secondary side |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620877455.6U CN205898871U (en) | 2016-08-12 | 2016-08-12 | Current transformer who opens a way is not afraid of to secondary side |
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| Publication Number | Publication Date |
|---|---|
| CN205898871U true CN205898871U (en) | 2017-01-18 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201620877455.6U Active CN205898871U (en) | 2016-08-12 | 2016-08-12 | Current transformer who opens a way is not afraid of to secondary side |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106291038A (en) * | 2016-08-12 | 2017-01-04 | 山东亿玛信诺电气有限公司 | Secondary side current transformer not being afraid of open circuit and preparation method thereof |
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2016
- 2016-08-12 CN CN201620877455.6U patent/CN205898871U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106291038A (en) * | 2016-08-12 | 2017-01-04 | 山东亿玛信诺电气有限公司 | Secondary side current transformer not being afraid of open circuit and preparation method thereof |
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