CN108666111A - Signal isolation transformer - Google Patents
Signal isolation transformer Download PDFInfo
- Publication number
- CN108666111A CN108666111A CN201810655176.9A CN201810655176A CN108666111A CN 108666111 A CN108666111 A CN 108666111A CN 201810655176 A CN201810655176 A CN 201810655176A CN 108666111 A CN108666111 A CN 108666111A
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- CN
- China
- Prior art keywords
- transformer
- winding
- voltage
- oil
- low pressure
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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.)
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/28—Coils; Windings; Conductive connections
- H01F27/30—Fastening or clamping coils, windings, or parts thereof together; Fastening or mounting coils or windings on core, casing, or other support
- H01F27/306—Fastening or mounting coils or windings on core, casing or other support
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/28—Coils; Windings; Conductive connections
- H01F27/32—Insulating of coils, windings, or parts thereof
- H01F27/324—Insulation between coil and core, between different winding sections, around the coil; Other insulation structures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
- H01F27/36—Electric or magnetic shields or screens
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Housings And Mounting Of Transformers (AREA)
- Testing Relating To Insulation (AREA)
Abstract
The invention discloses a kind of signal isolation transformers, transformer body is located in the oil tank of transformer full of transformer oil, circumference between low pressure winding and iron core is equipped with internal shield, circumference between low pressure winding and high-voltage winding is equipped with external shielding layer, internal shield and external shielding layer shape are highly consistent for the height and low pressure winding and high-voltage winding of open annular tubular internal shield and external shielding layer, internal shield and external shielding layer are grounded, low pressure winding is that triangle connects with winding one of in high-voltage winding, another winding is star-like connection, the rated voltage of low pressure winding is set to be tested 2 2.5 times of oil-immersed transformer experiment power supply input terminal rated voltage.The present invention is applied to oil-immersed transformer measurement of partial discharge, and which greatly reduce external signal interferences, improve the stability and accuracy of oil-immersed transformer measurement of partial discharge.
Description
Technical field
The invention belongs to transformer technology field, relate to more particularly to a kind of signal isolation transformer.
Background technology
It is 10000kVA's or more and Um ＞ 72.5kV for Um=72.5kV and rated capacity in transformer test
Oil-immersed transformer should all carry out measurement of partial discharge, and the maximum value of local discharging level is 500pC.Oil-immersed transformer part
There are many disturbing factors for discharge measuring process, wherein the interference from experiment power supply is one of them.It is dry from experiment power supply
Disturb the switching manipulation of including but not limited to electric power network, the electric discharge of itself of generating set, pressure regulator, intermediate transformer, experiment
Loop high-voltage corona and point discharge, the multipoint earthing of earthed system, current carrying contacts poor contact, radio transit signal etc.,
These interference signals can be coupled by experiment power supply circuit and introduce subject transformer, and be erroneously interpreted as the electric discharge arteries and veins of transformer
Punching, this will influence the stability and accuracy of partial discharge of transformer measurement.The interference signal even having is more than oil immersed type transformation
The local discharging level of device so that measurement can not carry out.
According to standard GB/T 1094.3《Power transformer third portion:Between dielectric level Insulation Test and external insulation air
Gap》Regulation, the background noise level of partial discharge test should be not more than 100pC.While in order to guarantee to detect and record part
The starting voltage and extinction voltage of electric discharge recommend background noise level to be far below 100pC.
Invention content
The purpose of the present invention is overcoming above-mentioned the deficiencies in the prior art, a kind of signal isolation transformer, this isolation are provided
Transformer itself does not generate shelf depreciation, and the high-frequency signal from mains side that can be decayed by the isolating transformer, but can allow
The test voltage and electric current of low frequency pass through.
To achieve the above object, present invention employs following technical solutions：
Signal isolation transformer, including oil tank of transformer 12 and outlet terminal, fuel tank 12 is interior to be equipped with transformer body, transformation
Device device body is located in the oil tank of transformer 12 full of transformer oil, and transformer body includes iron core 11,14 and of three-phase low-voltage winding
Three-phase high-voltage winding 13, the iron core 11 is circumferential to be provided with mutual corresponding low pressure winding 14 and high-voltage winding 13 from inside to outside,
It is characterized in that：Circumference between low pressure winding 14 and iron core 11 is equipped with internal shield 15, low pressure winding 14 and high-voltage winding
Circumference between 13 is equipped with external shielding layer 16, and internal shield 14 and external shielding layer 16 are metal foil, internal shield 14 and external screen
Cover the height and low pressure winding 14 and high-voltage winding 13 that 16 shape of layer is open annular tubular internal shield 14 and external shielding layer 16
Highly consistent, internal shield 14 and external shielding layer 16 are grounded, winding one of in low pressure winding 14 and high-voltage winding 13
It is connected for triangle, another winding is star-like connection, and the rated voltage U2 for setting low pressure winding 14 becomes as subject oil immersed type
2-2.5 times of 2 experiment power supply input terminal rated voltage of depressor.
When it is implemented, the magnetic flux density design value of iron core 11 in its saturation point hereinafter, preventing experiment power supply from passing through isolation
Harmonic wave and wave distortion are generated when transformer.
When it is implemented, S1 >=S2*I0%, the rated capacity of subject oil-immersed transformer 2 is S2, and oil immersed type transformation is isolated
The rated capacity of device 1 is S1, and the no-load current percentage of subject oil-immersed transformer 2 is I0%.
In partial discharge test, since the rated voltage U2 of low pressure winding is that subject oil-immersed transformer experiment power supply is defeated
Entering to hold 2-2.5 times of rated voltage, isolation oil-immersed transformer high-voltage winding 13 receives the voltage U5 and electric current I5 of power supply application,
By electromagnetism transform, voltage U6 and electric current I6 is applied to subject oil-immersed transformer by low pressure winding 14.Because in shelf depreciation
U6=1.8U4 ＜ U2 when experiment, that is, U6 are less than the rated voltage U2 of the low pressure winding 14 of isolating transformer.Isolating transformer
Shelf depreciation itself is not generated when being run less than its rated voltage, while passing through internal shield and external shielding layer, comes from power supply
Interference signal will be attenuated to more than 1 order of magnitude, the high frequency of power grid can be isolated after isolating transformer access pilot system
Impulse disturbances, so that the shelf depreciation of power end is interfered reduces.
The beneficial effects of the invention are as follows：The present invention is applied to oil-immersed transformer measurement of partial discharge, and isolating transformer exists
Shelf depreciation itself is not generated when being run less than its rated voltage, while passing through internal shield and external shielding layer, from power supply
Signal will be attenuated to more than 1 order of magnitude by interference, and can be decayed the high-frequency signal from mains side by the isolating transformer,
But the test voltage of low frequency and electric current can be allowed to pass through.External signal interference is greatly reduced, oil-immersed transformer office is improved
The stability and accuracy of portion's discharge measuring.
Description of the drawings
Invention will be further explained below with reference to the drawings and examples..
Fig. 1 is the outline structural diagram of isolating transformer embodiment of the present invention；
Fig. 2 is the elementary diagram of isolating transformer embodiment of the present invention；
Fig. 3 is the stem sectional schematic diagram of isolating transformer embodiment of the present invention；
Fig. 4 is the fundamental measurement line map of the threephase oil immersed transformer partial discharge test of the embodiment of the present invention；
Fig. 5 is the fundamental measurement line that the prior art does not have the threephase oil immersed transformer partial discharge test of isolating transformer
Lu Tu；
Fig. 6 is the application voltage system schematic diagram of oil-immersed transformer shelf depreciation routine test of the embodiment of the present invention.
In figure：1, oil-immersed transformer 2, subject oil-immersed transformer 3, partial discharge testing system 11, iron core 12, fuel tank is isolated
13, high-voltage winding 14, low pressure winding 15, internal shield 16, external shielding layer 21, input winding 22 become by formation testing, by formation testing become defeated
Go out winding.
Specific implementation mode
As shown in Figure 1, Figure 2, Fig. 3 and Fig. 4, the oil-immersed transformer partial discharge test isolation transformation for inhibiting power supply disturbance
Device, including oil tank of transformer 12 and outlet terminal, fuel tank 12 is interior to be equipped with transformer body, and transformer body, which is located at, is full of transformer
In the oil tank of transformer 12 of oil, transformer body includes iron core 11, three-phase low-voltage winding 14 and three-phase high-voltage winding 13, the iron
Core 11 is circumferential to be provided with mutual corresponding low pressure winding 14 and high-voltage winding 13 from inside to outside, between low pressure winding 14 and iron core 11
Circumference be equipped with internal shield 15, circumference between low pressure winding 14 and high-voltage winding 13 is equipped with external shielding layer 16, interior screen
It is metal foil to cover layer 14 and external shielding layer 16, and internal shield 14 and 16 shape of external shielding layer are open annular tubular internal shield 14
Highly consistent with the height and low pressure winding 14 and high-voltage winding 13 of external shielding layer 16, internal shield 14 and external shielding layer 16 connect
Ground, low pressure winding 14 are star-like connection, and high-voltage winding 13 connects for triangle, another winding is to set low pressure winding 14
Rated voltage U2 be to be tested 2-2.5 times of 2 experiment power supply input terminal rated voltage of oil-immersed transformer.The magnetic flux of iron core 11 is close
Design value is spent in its saturation point hereinafter, generating harmonic wave and wave distortion when preventing experiment power supply from passing through isolating transformer.S1≥S2*
The rated capacity of I0%, subject oil-immersed transformer 2 are S2, and the rated capacity of isolation oil-immersed transformer 1 is S1, is tested oil immersion
The no-load current percentage of formula transformer 2 is I0%.
In partial discharge test, since the rated voltage U2 of low pressure winding is that subject oil-immersed transformer experiment power supply is defeated
Entering to hold 2-2.5 times of rated voltage, isolation oil-immersed transformer high-voltage winding 13 receives the voltage U5 and electric current I5 of power supply application,
By electromagnetism transform, voltage U6 and electric current I6 is applied to subject oil-immersed transformer by low pressure winding 14.Because being put locally
U6=1.8U4 ＜ U2 when electric test, that is, U6 are less than the rated voltage U2 of the low pressure winding 14 of isolating transformer.Transformation is isolated
Device itself does not generate shelf depreciation when being run less than its rated voltage, while passing through internal shield and external shielding layer, from electricity
Signal will be attenuated to more than 1 order of magnitude by the interference in source.
It is to carry out measurement of partial discharge for 1 SFZ-125000/230 transformer actually to carry out shelf depreciation survey as follows
Using a contrast test of the prior art and structure of the invention when amount.
Test item parameter is as follows：
Rated capacity 125000kVA；
Rated voltage 230/66kV；
Rated current 313.8/1093.5A；
Rated frequency 50Hz；
Number of phases three-phase；
Tapping range ± 8 × 1.25%；
Connection series number YNd11；
Type of cooling ONAF；
Voltage regulating mode on-load voltage regulation；
Insulation grade anti-corrosion A；
Partial discharge discharge capacity (pC) requires to be less than 100.
Test basis GB1094.1-2013《The 1st part general provisions of power transformer》、GB1094.3-2003《Power transformer
Third portion:Dielectric level, Insulation Test and external insulation the air gap》And GB/T6451-2008《Oil-immersed power transformer skill
Art parameter and requirement》.
As shown in figure 5, the fundamental measurement line of the threephase oil immersed transformer partial discharge test according to the embodiment of the present invention
Road figure carries out partial discharge test, and becoming output winding 22 by formation testing is connected with the input terminal of partial discharge testing system 3, by formation testing
Become input winding 21 with experiment power supply to be connected.
1, experiment power supply：
1) 0~120000V of test voltage；
2) rated frequency 200Hz；
3) number of phases three-phase.
2, test procedure
1) testing background noise level is 75pC.
2) it is tested according to the application voltage of the routine test of oil-immersed transformer shelf depreciation shown in Fig. 6：
--- power under the voltage no more than U2/3；
--- 1.1Um/ √ 3 are risen to, 5min is kept；
--- it rises to U2 and keeps 5min；
--- rise to U1 its protracted test time 30S
--- it is reduced to U2 after experiment incessantly at once, and keeps at least 5min, measure shelf depreciation；
--- 1.1Um/ √ 3 are reduced to, 5min is kept；
--- when voltage drop is as low as U2/3 or less, cut off the power.
3) test result：It is 89pC to measure subject partial discharge of transformer amount.
As shown in figure 4, there is no the threephase oil immersed transformer partial discharge test of isolating transformer according to the prior art
Fundamental measurement line map carries out partial discharge test, increases the isolation oil-immersed transformer 1 of playscript with stage directions invention compared with Fig. 5,
Become output winding 22 by formation testing with the input terminal of partial discharge testing system 3 to be connected, input winding 21 is become by formation testing and oil immersion is isolated
The low pressure winding 14 of formula transformer 1 is connected, and the high-voltage winding 13 of isolation oil-immersed transformer 1 is connected with experiment power supply.
1, isolating transformer parameter：
1) rated capacity 3150kVA；
2) rated voltage 132/6kV；
3) rated current 13.8/303.1A；
4) rated frequency 50Hz；
5) number of phases three-phase；
6) Connection series number Dyn11；
7) type of cooling ONAN；
8) partial discharge discharge capacity (pC) is less than 10；
2, experiment power supply：
1) 0~120000V of test voltage；
2) rated frequency 200Hz；
3) number of phases three-phase；
3, test procedure and result：
1) testing background noise level is 9Pc；
2) it is 200Hz power supplys in the input terminal of isolating transformer input frequency, experiment pressurization and time press Fig. 6.Output end
It induces 200Hz voltages and is applied to subject step down side.
--- power under the voltage no more than U2/3；
--- 1.1Um/ √ 3 are risen to, 5min is kept；
--- it rises to U2 and keeps 5min；
--- rise to U1 its protracted test time 30S
--- it is reduced to U2 after experiment incessantly at once, and keeps at least 5min, measure shelf depreciation；
--- 1.1Um/ √ 3 are reduced to, 5min is kept；
--- when voltage drop is as low as U2/3 or less, cut off the power.
3) test result：It is 49pC to measure subject partial discharge of transformer amount.
The first experiment, supply voltage are applied directly on subject transformer, and background noise level 75pC, subject becomes
Depressor partial discharge quantity is 89pC；Second of experiment, supply voltage are applied to by isolating transformer on subject transformer, the back of the body
Scape noise level is 9pC.The first experiment it can be seen from, supply voltage are applied directly on subject transformer, and background is made an uproar
Sound level is 75pC, and the also high 26pC of partial discharge of transformer amount 49pC that than second test method measures do not meet experiment and want
It asks.
Finally it is pointed out that above example is only the more representational example of the present invention.It is clear that the invention is not restricted to
Above-described embodiment, acceptable there are many deformations.It is every according to the technical essence of the invention to any letter made by above example
Single modification, equivalent variations and modification, are considered as belonging to the scope of protection of the present invention.
Claims (3)
1. signal isolation transformer, including oil tank of transformer (12) and outlet terminal, fuel tank (12) is interior to be equipped with transformer body, becomes
Depressor device body be located at full of transformer oil oil tank of transformer (12) in, transformer body include iron core (11), three-phase low-voltage around
Group (14) and three-phase high-voltage winding (13), the iron core (11) are circumferentially provided with mutual corresponding low pressure winding (14) from inside to outside
With high-voltage winding (13), it is characterised in that：Circumference between low pressure winding (14) and iron core (11) is equipped with internal shield (15),
Circumference between low pressure winding (14) and high-voltage winding (13) is equipped with external shielding layer (16), internal shield (14) and external shielding layer
(16) it is metal foil, internal shield (14) and external shielding layer (16) shape are open annular tubular internal shield (14) and external shield
The height and low pressure winding (14) and high-voltage winding (13) of layer (16) are highly consistent, and internal shield (14) and external shielding layer (16) are equal
Ground connection, low pressure winding (14) and winding one of in high-voltage winding (13) are that triangle connects, another winding is star
Shape connects, and sets the rated voltage of low pressure winding (14) to be tested oil-immersed transformer (2) experiment power supply input terminal rated voltage
2-2.5 times.
2. signal isolation transformer according to claim 1, it is characterized in that the magnetic flux density design value of iron core (11) is at it
Below saturation point.
3. signal isolation transformer according to claim 1 or 2, it is characterized in that S1 >=S2*I0%, is tested oil immersed type transformation
The rated capacity of device (2) is S2, and the rated capacity of isolation oil-immersed transformer (1) is S1, the sky of subject oil-immersed transformer (2)
Load electric current percentage is I0%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810655176.9A CN108666111A (en) | 2018-06-23 | 2018-06-23 | Signal isolation transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810655176.9A CN108666111A (en) | 2018-06-23 | 2018-06-23 | Signal isolation transformer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108666111A true CN108666111A (en) | 2018-10-16 |
Family
ID=63773010
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810655176.9A Withdrawn CN108666111A (en) | 2018-06-23 | 2018-06-23 | Signal isolation transformer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108666111A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110459386A (en) * | 2019-08-19 | 2019-11-15 | 全球能源互联网研究院有限公司 | A kind of DC isolation transformer of same iron core expandable structure |
-
2018
- 2018-06-23 CN CN201810655176.9A patent/CN108666111A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110459386A (en) * | 2019-08-19 | 2019-11-15 | 全球能源互联网研究院有限公司 | A kind of DC isolation transformer of same iron core expandable structure |
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| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20181016 |
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| WW01 | Invention patent application withdrawn after publication |