CN209388829U - The anti-DC current transformer iron core of electromagnetic type and current transformer - Google Patents
The anti-DC current transformer iron core of electromagnetic type and current transformer Download PDFInfo
- Publication number
- CN209388829U CN209388829U CN201821912339.9U CN201821912339U CN209388829U CN 209388829 U CN209388829 U CN 209388829U CN 201821912339 U CN201821912339 U CN 201821912339U CN 209388829 U CN209388829 U CN 209388829U
- Authority
- CN
- China
- Prior art keywords
- core
- current transformer
- steel plate
- silicon steel
- alloy
- 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.)
- Active
Links
Landscapes
- Transformers For Measuring Instruments (AREA)
Abstract
The utility model belongs to transformer technical field, the anti-DC current transformer iron core of electromagnetic type and current transformer, including silicon steel plate core and alloy core, the shape of silicon steel plate core and alloy core is adapted, silicon steel plate core is equipped with a notch or two notch, incision cushioning insulation un-conducted magnetic material；Alloy core is that ultramicro-crystal alloy or permalloy coiling form；Alloy core is located at the inner cavity of silicon steel plate core, and the outer wall of alloy core is tightly attached to the inner wall of silicon steel plate core, forms the composite material iron core an of entirety；There are when DC component and half-wave DC amount in the utility model solution power grid primary system, the problem of conventional electromagnetic formula current transducer signal transfer admittance difference, in primary system, there are when larger DC component and half-wave DC amount, conversion signal ratio error is still able to satisfy no more than 2%, phase error is not more than 120 ' electromagnetic current transducer.
Description
Technical field
The utility model belongs to transformer technical field, in particular to one kind is half-wave DC or presence in primary system
In the case of DC component, the electromagnetic current transducer of a signal still can be accurately converted.
Background technique
Current transformer is one of key equipment in electric system.It can believe the high current in power grid primary system
Number, according to the ratio of regulation, the low current signal (1A or 5A) for being converted to standard of high accuracy, by be followed by it is secondary based on
Amount, measurement, protection system use, it may be said that the conversion accuracy and the trade settlement accuracy of the electricity charge, power grid of current transformer are transported
Monitoring and safe operation of electric network of the row data acquisition with operating status are closely related.
With the fast development of China's economy, network load also becomes increasingly complex, and a large amount of frequency conversion equipments, rectifier equipment etc. are non-
The access of linear load leads to the sine wave of original normal power supply in system, and there is DC components, and there are also some electrical equipments
It is to be driven using the half-wave after diode rectification, and the component of these non-sinusoidal waveforms can be in the iron core of current transformer
The asymmetrical magnetic flux of biasing is formed, this magnetic flux is superimposed with industrial frequency AC magnetic flux, and the operating point for eventually leading to iron core is improved, iron
The heart quickly enters saturation region, can not accurately switching current signal, the operational safety of accuracy and power grid to electricity metering bring
Very big threat.
Signal after diode rectification, the secondary waveform and one after the conversion of conventional current mutual inductor are monitored using detection device
The comparison of secondary actual waveform, shown in Fig. 7, in rated operation point, ratio error -86.757%, phase error 4300 ', mutual inductor
It can not work normally.
It is counted according to power supply department, within the scope of State Grid Corporation of China, annual total electricity sales amount is 2,000,000,000,000 degree, and platform area line loss is about
6% is accounted for, wherein caused by 1% is DC component bring measurement deviation, only this item will lack metering electric charge up to 20,000,000,000 every year
Degree.
In addition, when the main electricity filching means of former are that artificially addition DC quantity or mutual inductor are secondary in current transformer
Series diode in route makes conventional current mutual inductor enter saturation, reduces secondary output.
The expert of Chongqing power supply company has delivered one and entitled " diode halfwave rectifier has been utilized to carry out the case point of stealing
The article of analysis ", example is shown, by this stealing mode, conventional current mutual inductor metering electric charge only has the 16% of the real electricity charge
Left and right.
In the prior art, for the electronics Current Transformer of output milliampere level signal, using ultramicro-crystal alloy iron core
Type of incision, but the electric power Current Transformer for exporting amp steps signal, are still unable to satisfy accuracy requirement.For
This, conversion signal ratio can be still able to satisfy in primary system there are when larger DC component and half-wave DC amount by researching and developing one kind
It is worth error and is not more than 2%, it is the urgent need of current electric system that phase error, which is not more than 120 ' electromagnetic current transducer,
It asks.
Utility model content
The utility model is to provide a kind of anti-DC current transformer iron core knot of electromagnetic type for above-mentioned disadvantage
Structure, and the current transformer of this core construction production is used, there are DC component and half-waves in solution power grid primary system
When DC quantity, the problem of conventional electromagnetic formula current transducer signal transfer admittance difference.
The used technical solution of the technical issues of the utility model solves is:
The anti-DC current transformer iron core of electromagnetic type, it is characterized in that including silicon steel plate core and alloy core, silicon steel sheet iron
The shape of the heart and alloy core is adapted, and silicon steel plate core is equipped with a notch (unilateral notch) or two notch are (bilateral to cut
Mouthful), incision cushioning insulation un-conducted magnetic material；Alloy core is that ultramicro-crystal alloy or permalloy coiling form；Alloy core
Positioned at the inner cavity of silicon steel plate core, the outer wall of alloy core is tightly attached to the inner wall of silicon steel plate core, forms the compound of an entirety
Material iron core.Lower Fig. 8 is theory analysis insulation gap iron core and closed core magnetization characteristic theory comparison diagram.
Consider tested half-wave current as shown in Figure 9, because it is cyclical signal, it can be considered to current transformers
Lower state is operated in, i.e., each period is duplicate working condition.
Half-wave current shown in Fig. 9 can indicate are as follows:
It can be seen that the half-wave current is by DC current Imπ and fundamental wave and each even-order harmonic composition, and it is humorous at 6 times
After wave, harmonic amplitude declines rapidly.For current transformer, the DC quantity being tested in electric current is cannot to sense secondary side
's.Each subwave content (incomplete Fourier analysis) figure of half-wave as shown in Figure 10.
It is assumed that electric current converts of ac entirely accurate, then, secondary output are as follows:
Wherein K is no-load voltage ratio, that is, formula (1) eliminates DC quantity, and it is constant to be equivalent to waveform in Fig. 9, is exactly moved down
Imπ, here it is the reasons (refer to Figure 11) identical as tested waveform of output waveform in our experiments.
For fundamental wave and harmonic content, as long as iron core operates in linear zone, can accurately convert.But due to being tested half-wave
Containing fixed DC quantity in electric current, iron core just has fixed direct current flux.For the conversion of fundamental wave and harmonic content,
Original work zero point is just raised.For closed core, the presence of DC magnetizing magnetic flux makes iron core enter saturation, closed core
It does not work, can be considered air.For there is the iron core of insulation gap, biggish excitation current is inherently needed to can be only achieved needs
B, it is possible to design insulation gap size, so that the fixation DC quantity contained in tested half-wave current is in the iron core for having insulation gap
The B0 of generation is much smaller than the saturation point Bs of iron core, and Bs-B0 is greater than the of ac of fundamental wave and harmonic content composition in Current Mutual Inductance
The variation range of the iron core B needed when converting in device, then of ac operates in linear zone, so that it may linearly conversion formula
(2) it is measured shown in.
In an embodiment of the present invention, incision cushioning insulation un-conducted magnetic material is that polyester film or PMP are compound
Paper, to guarantee incision size and improve the average dielectric constant of integral core.
In an embodiment of the present invention, the incision size of silicon steel plate core is less than 1mm；
In an embodiment of the present invention, the insulating materials such as alloy core epoxy resin curing molding or it is mounted on shield
It is fixed in box.
In an embodiment of the present invention, silicon steel plate core uses the coiling of low-loss grain-oriented Si steel sheet, is round, oval
Shape is rectangular；Alloy core is identical as the shape of silicon steel plate core, is round, oval or rectangular.
In an embodiment of the present invention, mutually merge external on the silicon steel plate core and alloy core stacked twine
Around insulating materials as insulation and buffer layer.
In an embodiment of the present invention, insulation and buffer layer are crimped paper or insulating tape.
The utility model is designed by the iron of the high material manufacture of the initial permeabilities such as ultramicro-crystal alloy (or permalloy)
The heart, the double core constructions being composed with low-loss silicon steel plate core, wherein silicon steel plate core is unilateral or bilateral cut with one
Mouthful, the special insulation un-conducted magnetic material of incision cushioning, to guarantee incision size and improve the average dielectric of integral core
Constant.The uniform coiling secondary winding on combining double iron cores again, is poured to form finished product by thermosetting resin.Use the compound iron
The current transformer of heart production is solved there are when DC component and half-wave DC amount in power grid primary system, and conventional electromagnetic formula is electric
The problem of current transformer signal transfer admittance difference.The utility model is technically characterized by comprising the steps as follows: alloy core for guaranteeing conventional friendship
Meet the requirement of class of accuracy 0.2S when stream signal conversion, in the presence of DC component and half-wave DC, it is full that signal converts class of accuracy
Sufficient ratio error 2%, the requirement of phase error 120 '.More crucially product size is small, and it is existing to meet State Grid Corporation of China
The calibrating requirement of automatic Verification assembly line.
The utility model also provides a kind of current transformer, including the anti-direct current of electromagnetic type described in any of the above embodiment
Current transformer iron core.
In an embodiment of the present invention, the uniform coiling mutual inductor of the anti-DC current transformer iron core of electromagnetic type it is secondary
Winding, the head and end of winding are drawn out to secondary wiring terminals, respectively head end s1, end s2.
In an embodiment of the present invention, accuracy test is done after the completion of secondary winding coiling, compensated by fractional turns,
Short circuited turn compensation, magnetic shunt compensation and (or) capacitor and inductance compensation means reduced value error, phase error are adjusted, until
Data fit accuracy requirement, then whole thermosetting resin casting curing molding.
The working principle of the anti-DC current transformer of the utility model is: using closure alloy core and closing with insulation gap
The double core constructions for closing silicon steel plate core composition, when primary current is free of DC quantity, two iron cores are unsaturated, are closed alloy
Iron core plays a major role, therefore can guarantee the grade accuracy of conventional current mutual inductor 0.2S under the conditions of current sinusoidal wave；When primary
When electric current contains DC quantity, closure alloy core saturation, the silicon steel plate core with insulation gap plays a major role, as long as with insulation gap
Silicon steel plate core magnetization curve on dc point it is more sufficiently low than inflection point, be just avoided that with insulation gap silicon steel plate core exist
Primary current is containing the saturation in the case of DC quantity, to ensure that the anti-DC characteristic of the current transformer, Current Mutual Inductance at this time
The error of device is mainly determined by the silicon steel plate core with insulation gap.
The beneficial effects of the utility model are: the utility model solves in power grid primary system, there are DC component and half-waves
When DC quantity, the problem of conventional electromagnetic formula current transducer signal transfer admittance difference, in primary system, there are larger direct currents point
When amount and half-wave DC amount, conversion signal ratio error is still able to satisfy no more than 2%, phase error is not more than 120 ' electromagnetism
Formula current transformer, product size is small, meets the calibrating requirement of the existing automatic Verification assembly line of State Grid Corporation of China.
Detailed description of the invention
Utility model is further illustrated with reference to the accompanying drawings and examples.
Fig. 1 is the unilateral notch features schematic diagram of the utility model embodiment silicon steel plate core.
Fig. 2 is the utility model embodiment silicon steel plate core Double-Notched structural schematic diagram.
Fig. 3 is the anti-DC current transformer core construction schematic diagram of the utility model embodiment electromagnetic type.
Fig. 4 is the anti-DC current transformer iron core outline structural diagram of the utility model embodiment electromagnetic type.
Fig. 5 is the anti-DC current transformer structural schematic diagram of the utility model embodiment electromagnetic type.
Fig. 6 is the anti-DC current transformer outline structural diagram of the utility model embodiment electromagnetic type.
Fig. 7 is pair of the secondary waveform and an actual waveform after the conversion of the utility model embodiment conventional current mutual inductor
Than figure.
Fig. 8 is that the utility model embodiment theory analysis insulation gap iron core and closed core magnetization characteristic theory compare
Figure.
Fig. 9 is the state diagram of the utility model embodiment half-wave current.
Figure 10 is each subwave content (incomplete Fourier analysis) figure of the utility model embodiment half-wave.
Figure 11 is the utility model embodiment output waveform and tested comparison of wave shape figure.
Figure 12 is secondary waveform after the anti-DC current transformer conversion of the utility model embodiment electromagnetic type and primary real
The comparison diagram of border waveform.
Figure 13 is the exciting characteristic curve figure of the utility model embodiment prior art current mutual inductor iron core.
Figure 14 is the exciting characteristic curve figure of the anti-DC current transformer composite iron core of the utility model embodiment electromagnetic type.
In figure: 1, silicon steel plate core 2, alloy core 3, insulation and buffer layer 4, secondary winding 5, external insulation 11, absolutely
Edge un-conducted magnetic material.
Specific embodiment
With reference to the accompanying drawing, by specific embodiment, to the technical solution of the utility model carry out it is clear, completely retouch
It states.
Please refer to shown in Fig. 1-6, the utility model provides a kind of anti-DC current transformer iron core of electromagnetic type, Fig. 1 extremely
In Fig. 3, a kind of anti-DC current transformer iron core of electromagnetic type, including silicon steel plate core 1 and alloy core 2,1 He of silicon steel plate core
Alloy core 2 is all made of circular configuration, and shape is adapted, and in the structure of Fig. 1, silicon steel plate core 1 is equipped with a notch, i.e., unilateral
Notch, in the structure of Fig. 2, silicon steel plate core 1 is equipped with two notch, i.e. Double-Notched, in the utility model embodiment, silicon steel sheet
Iron core 1 uses unilateral notch, and the incision size of silicon steel plate core 1 is less than 1mm, incision cushioning insulation un-conducted magnetic material 11；It closes
Golden iron core 2 is that ultramicro-crystal alloy or permalloy coiling form；Ultramicro-crystal alloy such as amorphous nano peritectic alloy 1K107, ultracrystallite
Alloy 1K101, alloy core 2 are located at the inner cavity of silicon steel plate core 1, and the outer wall of alloy core 2 is tightly attached to the interior of silicon steel plate core 1
Wall forms the composite material iron core an of entirety.
In the utility model embodiment, incision cushioning insulate un-conducted magnetic material 11 be polyester film or PMP extrusion coating paper,
To guarantee incision size and improve the average dielectric constant of integral core.
In the utility model embodiment, the insulating materials curing molding such as epoxy resin of alloy core 2.Alloy core 2
It may be mounted in shield box and be fixed into an entirety.
In the utility model embodiment, silicon steel plate core 1 uses the coiling of low-loss grain-oriented Si steel sheet, 1 He of silicon steel plate core
Alloy core 2 is all made of circular configuration.But not limited to this, silicon steel plate core 1 and alloy core 2 can be all made of oval knot
Structure, or it is all made of square structure.
In the utility model embodiment, the composite material iron core of silicon steel plate core 1 and one entirety of formation of alloy core 2,
It is externally wrapped with insulating materials as insulation and buffer layer 3.Insulation and buffer layer 3 are crimped paper or insulating tape, are insulated and slow
It is without being limited thereto to rush layer 3.
It please refers to shown in Fig. 5 and Fig. 6, the utility model also provides electromagnetic type anti-DC current transformer, including to take up an official post
The anti-DC current transformer iron core of electromagnetic type described in one embodiment.
In an embodiment of the present invention, current transformer iron core includes silicon steel plate core 1 and alloy core 2, alloy
Iron core 2 is located at the inner cavity of silicon steel plate core 1, and the outer wall of alloy core 2 is tightly attached to the inner wall of silicon steel plate core 1, and formation one is whole
The composite material iron core of body, incision cushioning insulate un-conducted magnetic material 11 for polyester film or PMP extrusion coating paper, to guarantee notch
Size and the average dielectric constant for improving integral core.The insulating materials curing moldings such as the epoxy resin of alloy core 2.Silicon steel
Piece iron core 1 and alloy core 2 form the composite material iron core of an entirety, are externally wrapped with insulating materials as insulation and buffering
Layer 3.In insulation and buffer layer 3, the secondary winding 4 of uniform coiling mutual inductor, the head and end of winding is drawn out to secondary connection
Terminal, respectively head end s1, end s2.In the utility model embodiment, secondary winding does accuracy examination after the completion of 4 systems
It tests, passes through fractional turns compensation, short circuited turn compensation, magnetic shunt compensation and (or) capacitor and inductance compensation means reduced value error, phase
Position error is adjusted, and until data fit accuracy requirement, is externally wrapped with external insulation 5, external insulation 5 is crimped paper or insulating cement
Band etc., external insulation 5 is without being limited thereto, then whole again to be poured curing molding with thermosetting resin.
The utility model is designed by the iron of the high material manufacture of the initial permeabilities such as ultramicro-crystal alloy (or permalloy)
The heart, the double core constructions being composed with low-loss silicon steel plate core, wherein silicon steel plate core is unilateral or bilateral cut with one
Mouthful, the special insulation un-conducted magnetic material of incision cushioning, to guarantee incision size and improve the average dielectric of integral core
Constant.The uniform coiling secondary winding on combining double iron cores again, is poured to form finished product by thermosetting resin.The utility model
It is technically characterized by comprising the steps as follows: requirement of the alloy core for guaranteeing to meet class of accuracy 0.2S when the conversion of regular alternating current signal, in DC component
In the presence of half-wave DC, signal conversion class of accuracy meets ratio error 2%, the requirement of phase error 120 '.It is more crucial
It is that product size is small, meets the calibrating requirement of the existing automatic Verification assembly line of State Grid Corporation of China.The utility model embodiment electricity
The comparison diagram of secondary waveform and an actual waveform after the anti-DC current transformer conversion of magnetic-type is as shown in Figure 12.
This finished product completed in the utility model embodiment to coiling does accuracy test, passes through fractional turns compensation, short circuit
The means reduced value such as circle compensation, magnetic shunt compensation, capacitor and inductance compensation error, phase error are adjusted, until data symbols
Close accuracy requirement, then whole thermosetting resin casting curing molding.The work of the anti-DC current transformer of the utility model
Principle is: double core constructions of the closed core composition using closed core and with insulation gap, when primary current is free of DC quantity
When, two iron cores are unsaturated, and closure alloy core plays a major role, therefore can guarantee conventional current under the conditions of current sinusoidal wave
The grade accuracy of mutual inductor 0.2S；When primary current contains DC quantity, closure alloy core saturation, the silicon steel sheet with insulation gap
Iron core plays a major role, as long as the dc point on the silicon steel plate core magnetization curve with insulation gap is more sufficiently low than inflection point,
Saturation of the silicon steel plate core with insulation gap when primary current is containing DC quantity is avoided that, to ensure that the Current Mutual Inductance
The anti-DC characteristic of device, the error of current transformer is mainly determined by the silicon steel plate core with insulation gap at this time.With model:
LMZ2K, no-load voltage ratio: 500/5, accuracy: 0.2S/2, capacity: for 5VA product, Figure 13 is prior art current mutual inductor iron core
Exciting characteristic curve figure.
Figure 14 is the exciting characteristic curve figure of the anti-DC current transformer composite iron core of the utility model embodiment electromagnetic type,
It can be seen that 3.3 times to conventional products of the anti-saturation capability improving of utility model product composite iron core.
The above is only the preferred embodiment of the present invention, not thereby limits the patent protection of the utility model
Range, it is all with equivalent structure transformation made by the utility model specification and accompanying drawing content, directly or indirectly it is used in it
His relevant technical field similarly includes within the protection scope of the present utility model.
Claims (9)
1. the anti-DC current transformer iron core of electromagnetic type, it is characterized in that including silicon steel plate core and alloy core, silicon steel plate core
It is adapted with the shape of alloy core, silicon steel plate core is equipped with a notch or two notch, and the insulation of incision cushioning is non-magnetic
Material；Alloy core is that ultramicro-crystal alloy or permalloy coiling form；Alloy core is located at the inner cavity of silicon steel plate core, alloy
The outer wall of iron core is tightly attached to the inner wall of silicon steel plate core, forms the composite material iron core an of entirety.
2. the anti-DC current transformer iron core of electromagnetic type according to claim 1, it is characterized in that the insulation of incision cushioning is not
Permeability magnetic material is polyester film or PMP extrusion coating paper.
3. the anti-DC current transformer iron core of electromagnetic type according to claim 1, it is characterized in that the notch of silicon steel plate core
Size is less than 1mm.
4. the anti-DC current transformer iron core of electromagnetic type according to claim 1, it is characterized in that alloy core asphalt mixtures modified by epoxy resin
Rouge insulating materials curing molding is mounted on fixed in shield box.
5. the anti-DC current transformer iron core of electromagnetic type according to claim 1, it is characterized in that silicon steel plate core is using low
Grain-oriented Si steel sheet coiling is lost, is round, oval or rectangular；Alloy core is identical as the shape of silicon steel plate core, for it is round,
It is oval or rectangular.
6. the anti-DC current transformer iron core of electromagnetic type according to claim 1 stacks it is characterized in that mutually merging
Silicon steel plate core and alloy core on be externally wrapped with insulating materials as insulation and buffer layer.
7. the anti-DC current transformer iron core of electromagnetic type according to claim 6, it is characterized in that insulation and buffer layer are wrinkle
Line paper or insulating tape.
8. a kind of current transformer, it is characterized in that including the anti-DC current transformer of electromagnetic type as claimed in claim 1 to 7
Iron core.
9. current transformer according to claim 8, it is characterized in that the anti-DC current transformer iron core of electromagnetic type uniformly around
The secondary winding of mutual inductor processed, the head and end of winding are drawn out to secondary wiring terminals, respectively head end and end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821912339.9U CN209388829U (en) | 2018-11-20 | 2018-11-20 | The anti-DC current transformer iron core of electromagnetic type and current transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821912339.9U CN209388829U (en) | 2018-11-20 | 2018-11-20 | The anti-DC current transformer iron core of electromagnetic type and current transformer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209388829U true CN209388829U (en) | 2019-09-13 |
Family
ID=67865093
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821912339.9U Active CN209388829U (en) | 2018-11-20 | 2018-11-20 | The anti-DC current transformer iron core of electromagnetic type and current transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209388829U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109411205A (en) * | 2018-11-20 | 2019-03-01 | 中国电力科学研究院有限公司 | The anti-DC current transformer iron core of electromagnetic type and current transformer |
-
2018
- 2018-11-20 CN CN201821912339.9U patent/CN209388829U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109411205A (en) * | 2018-11-20 | 2019-03-01 | 中国电力科学研究院有限公司 | The anti-DC current transformer iron core of electromagnetic type and current transformer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107068373B (en) | Anti direct current transformer | |
| CN103558573B (en) | A kind of performance test methods of voltage transformer (VT) | |
| CN105425175A (en) | Iron core remanent magnetism elimination and measurement method based on polarity-reversal DC voltage source | |
| CN107703368B (en) | Method for measuring inductance of transformer in deep saturation state | |
| Emanuel et al. | Current harmonics measurement by means of current transformers | |
| CN107015178A (en) | The measuring method of transformer core material hysteresis curve under harmonic excitation | |
| CN109411205A (en) | The anti-DC current transformer iron core of electromagnetic type and current transformer | |
| CN108459193A (en) | Alternating current measuring device | |
| CN209388829U (en) | The anti-DC current transformer iron core of electromagnetic type and current transformer | |
| CN209591744U (en) | The anti-DC current transformer iron core of electromagnetic type and the anti-DC current transformer of electromagnetic type | |
| KR101192830B1 (en) | Current transformer and electric energy meter | |
| CN209312584U (en) | A kind of anti-DC current transformer | |
| CN107677975A (en) | A kind of measuring method of excitation curve under transformer saturation state | |
| CN112271061A (en) | Current transformer for metering | |
| CN205666125U (en) | Anti direct current measuring current transformer | |
| CN102426909A (en) | Direct current resisting transformer based on composite magnetic core and manufacturing method thereof | |
| CN104215928A (en) | Analytical model method for current conversion ratio and phase difference of open-type current transformer | |
| CN203312022U (en) | Low-voltage direct-current-resisting current mutual inductor | |
| CN105957696B (en) | Current transformer for DC resistance measurement and preparation method thereof | |
| CN204666711U (en) | A kind of device measuring DC current | |
| CN109378179A (en) | The anti-DC current transformer iron core of electromagnetic type and the anti-DC current transformer of electromagnetic type | |
| CN106653339A (en) | Current transformer | |
| CN205789476U (en) | Current transformer | |
| Lu et al. | Experiment and Simulation of the Accuracy of Current Transformer with a New Core Material | |
| CN204666709U (en) | Half magnetic core current sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 430074 Hubei Province, Wuhan city Hongshan District Luoyu Road No. 143 Patentee after: CHINA ELECTRIC POWER RESEARCH INSTITUTE Co.,Ltd. Patentee after: Wuhan Nari Limited Liability Company of State Grid Electric Power Research Institute Patentee after: Zhejiang Tianji Instrument Transformer Co.,Ltd. Address before: 430074 Hubei Province, Wuhan city Hongshan District Luoyu Road No. 143 Patentee before: CHINA ELECTRIC POWER RESEARCH INSTITUTE Co.,Ltd. Patentee before: Wuhan Nari Limited Liability Company of State Grid Electric Power Research Institute Patentee before: ZHEJIANG HORIZON INSTRUMENT TRANSFORMERS Co.,Ltd. |
|
| CP01 | Change in the name or title of a patent holder |