CN111354538A - Current transformer for solid cabinet - Google Patents
Current transformer for solid cabinet Download PDFInfo
- Publication number
- CN111354538A CN111354538A CN201811561836.3A CN201811561836A CN111354538A CN 111354538 A CN111354538 A CN 111354538A CN 201811561836 A CN201811561836 A CN 201811561836A CN 111354538 A CN111354538 A CN 111354538A
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- China
- Prior art keywords
- insulator
- primary
- current transformer
- terminal
- solid
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- 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
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- 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
- H01F27/02—Casings
- H01F27/022—Encapsulation
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- 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
- H01F27/29—Terminals; Tapping arrangements for signal inductances
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- 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
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F38/00—Adaptations of transformers or inductances for specific applications or functions
- H01F38/20—Instruments transformers
- H01F38/22—Instruments transformers for single phase ac
- H01F38/28—Current transformers
- H01F38/30—Constructions
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Transformers For Measuring Instruments (AREA)
Abstract
The invention relates to a high-voltage measuring and protecting device of an electric power system, in particular to a current transformer for a solid cabinet, which comprises an insulator and a coil body sealed in the insulator, wherein primary wiring terminals are arranged at two ends of the insulator, a secondary wiring terminal is arranged above the insulator, the insulator is of an integrated structure formed by pouring epoxy resin, an aluminum powder layer is sprayed on the outer surface of the insulator, the primary wiring terminal at one end of the insulator is a contact type primary wiring terminal, and the other end of the insulator is a groove type primary wiring terminal. The invention is formed by vacuum casting of epoxy resin, has small volume, large creepage distance, high dynamic and thermal stability current, high metering precision, moisture resistance, condensation resistance and electricity larceny prevention, and can be widely applied to the transformation of a switch cabinet of a power system and a newly designed switch cabinet.
Description
Technical Field
The invention relates to a high-voltage measurement and protection device of an electric power system, in particular to a current transformer for a solid cabinet, which is suitable for a 35kV solid insulation cabinet.
Background
The current transformer of 35kV solid insulation cabinet is a device for measuring current, electric energy or relay protection in the solid switch cabinet of the power system, the current transformer for the solid insulation cabinet used in the power system adopts a totally-enclosed outer-sleeved aluminum shell structure (i.e. a structure that a primary winding, a secondary winding, an iron core and other components are cast into an integral insulation and an aluminum shell is sleeved outside), the defects of small volume, low winding precision, low load, complex processing technology of the aluminum shell, easy discharge of a gap between the aluminum shell and a cast body after the aluminum shell is sleeved, short service life, low partial discharge qualification rate and the like exist, the product performance is prolonged along with the service time, the precision and the insulation of the device are reduced to different degrees, which becomes a hidden trouble of safe operation of the device in the power system, the problems are always puzzled to electric power system design and maintenance personnel, and become the problems which are urgently solved in upgrading, transformation and development of the current transformer for the 35kV solid cabinet of the electric power system.
Disclosure of Invention
Aiming at the problems, the invention aims to provide a current transformer for a solid cabinet, which aims to solve the problems of low precision, low load, low partial discharge qualification rate, short service life of a product and the like in the conventional 35kV solid insulation cabinet.
In order to achieve the purpose, the invention adopts the following technical scheme:
a current transformer for a solid cabinet comprises an insulator and a coil body sealed in the insulator, wherein primary wiring terminals are arranged at two ends of the insulator, secondary wiring terminals are arranged above the insulator, the insulator is of an integrated structure formed by pouring epoxy resin, and an aluminum powder layer is sprayed on the outer surface of the insulator.
The primary wiring terminal at one end of the insulator is a contact type primary wiring terminal, and the other end of the insulator is a groove type primary wiring terminal.
The groove type primary wiring terminals are two and are respectively arranged along the transverse direction and the vertical direction.
And the outer sides of the contact type primary wiring terminal and the groove type primary wiring terminal are both provided with a high-voltage shielding net.
The groove type primary wiring terminal is characterized in that a mounting flange is arranged at the end part of the groove type primary wiring terminal in the vertical direction, and a low-voltage shielding net is arranged in the mounting flange.
The outside of secondary binding post is equipped with the secondary wire connection cover, the side of secondary wire connection cover is equipped with semicircle wire hole.
The coil body comprises an iron core, a primary winding and a secondary winding, wherein the secondary winding is wound on the iron core, the primary winding is sleeved on the outer side of the secondary winding, and two ends of the primary winding are respectively connected with the primary wiring terminal.
The insulator is of a square structure.
The invention has the following advantages and beneficial effects:
1. small size and large creepage distance: the mounting plate is an integrated structure which is formed by vacuum casting of epoxy resin and sprayed with aluminum powder on the surface, the iron core is sealed in the insulating material, the structural design is optimized, the product has small volume, light weight, good partial discharge effect and long service life, and can be flexibly mounted in a 35kV solid cabinet to be used for current and electric energy metering and relay protection.
2. The dynamic and thermal stability current is high, and the metering accuracy is high: the primary dynamic thermal stability current of the invention is high, and can effectively avoid the over-high temperature rise and insulation damage of the mutual inductor caused by system short circuit and over-current; the metering coil can be made into a complex transformation ratio form, the metering precision can reach 0.2S level, and the metering accuracy of the product under the conditions of wide load and large load change is effectively ensured.
3. Full-sealing, dampproof, prevent condensation: the vacuum casting machine is integrally formed by vacuum casting of epoxy resin, all parts are sealed in the insulating material, so that the moisture-proof and anti-condensation functions of the product are ensured, and the performance degradation phenomenon of the product caused by moisture and condensation of the operating environment is avoided.
4. Transparentization for electricity larceny prevention: the secondary wiring terminal is positioned in the secondary wiring cover made of transparent materials, the actual situation of secondary wiring can be conveniently and directly observed, and the secondary wiring cover has a lead sealing function, so that the phenomenon of electricity stealing caused by switching the secondary wiring is avoided.
Drawings
FIG. 1 is an external structural view of the present invention;
fig. 2 is a schematic view of the internal structure of the present invention.
In the figure: 1 is a contact type primary wiring terminal; 2 is a secondary wiring terminal; 3 is a primary winding; 4 is a secondary winding; 5 is an iron core; 6 is a low-voltage shielding net; 7 is a high-voltage shielding net I; 8 is a high-voltage shielding net II; 9 is a high-voltage shielding net III; 10 is a secondary wiring cover; 11 is a semicircular wire outlet hole; 12 is an aluminum powder layer; an enclosure screw 13; 14 is an insulator; 15 is a groove type primary connection terminal.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.
As shown in fig. 1-2, the current transformer for a solid cabinet provided by the present invention includes an insulator 14 and a coil body enclosed in the insulator 14, wherein primary connection terminals are disposed at two ends of the insulator 14, a secondary connection terminal 2 is disposed above the insulator 14, the insulator 14 is cast into an integral structure by epoxy resin, and an aluminum powder layer 12 is sprayed on an outer surface of the insulator 14 to form a shielding and insulating function.
The insulator 14 is of a square structure, so that the product structure is more reasonable and the size is compact on the basis of ensuring the insulation of the internal coil and the uniform distance of an electric field. The primary terminal at one end of the insulator 14 is a contact type primary terminal 1, and the other end is a groove type primary terminal 15.
Further, the two groove-shaped primary connecting terminals 15 are respectively arranged along the transverse direction and the vertical direction, so that the groove-shaped primary connecting terminals can be conveniently connected with mounting interfaces in different directions. The outer sides of two groove type primary connecting terminals 15 arranged in the transverse direction and the vertical direction are respectively provided with a high-voltage shielding net I7 and a high-voltage shielding net II 8, and the outer side of the contact type primary connecting terminal 1 is provided with a high-voltage shielding net III 9. An installation flange is arranged at the end part of the groove type primary wiring terminal 15 arranged in the vertical direction, and a low-voltage shielding net 6 is arranged in the installation flange. The high-voltage shielding net I7, the high-voltage shielding net II 8 and the low-voltage shielding net 6 are all sealed in the insulator 14.
The low-voltage shielding net is arranged inside the insulator 14, the aluminum powder is sprayed on the outer surface of the insulator 14 after sand blasting to form an integral low potential, and the close connection between the pouring body and the aluminum powder and the pouring body is ensured, so that the partial discharge effect is optimal, and the service life of the product is long.
The outer side of the secondary wiring terminal 2 is provided with a secondary wiring cover 10, and the side surface of the secondary wiring cover 10 is provided with a semicircular wire outlet hole 11, so that the secondary lead can be led out conveniently and the electricity stealing prevention function can be realized. The secondary wiring cover 10 is made of transparent materials, so that the actual situation of secondary wiring can be conveniently and directly observed, and the function of electricity larceny prevention is achieved.
The coil body comprises an iron core 5, a primary winding 3 and a secondary winding 4, wherein the secondary winding 4 is wound on the iron core 5, the primary winding 3 is sleeved on the outer side of the secondary winding 4, and two ends of the primary winding are respectively connected with a primary wiring terminal.
The manufacturing process of the invention is as follows:
the secondary winding 4 is uniformly wound on the annular iron core 5, the primary winding 3 is wound by using a special tool and is assisted in binding insulating materials, and after the secondary winding 4 is bound, buffered and bound, a coil body with a primary wiring terminal 1, the primary winding 3, the secondary winding 4 and a secondary wiring terminal 2 is formed; the secondary winding 4 is fixed on the mould, the primary winding 3 is fixed on the mould by adopting a primary wiring terminal, the distance is adjusted and then the secondary winding is formed by epoxy resin vacuum pouring and curing, and then the secondary winding is an integrated structure, finally, the secondary wiring cover 10 adopts the cover screw 13 to seal the secondary wiring terminal 2, when a user uses the secondary wiring cover, the actual situation of secondary wiring can be conveniently and directly observed, the cover screw 13 and the secondary wiring cover 10 are provided with lead sealing holes, and the side surface of the secondary wiring cover is provided with the semicircular wire outlet hole 11, so that the secondary lead can be conveniently led out, and meanwhile, the secondary winding has an anti-electricity-.
The casting body for encapsulating the primary winding 3 and the secondary winding 4 is in a cuboid type, one end of the casting body is in a contact form, and the other end of the casting body is in a groove form, so that the use requirement of a solid cabinet is effectively met; on the basis of ensuring the insulation of the internal coil and the uniform distance of an electric field, the product has more reasonable structure and compact size; the aluminum powder layer 12 sprayed on the surface of the casting body is connected with the low-voltage shielding net 6 to effectively shield high voltage, so that the surface of the casting body is low voltage.
When the intelligent cabinet is used, the mutual inductor installation insert is fixed with the installation hole of the cabinet body through the connecting piece, and then the primary bus and the secondary cable are electrically and mechanically connected. And finally, installing the secondary wiring cover, namely completing the installation.
The current transformer for the solid cabinet is a new product designed completely according to national standards, adopts a coiled iron core, utilizes an electromagnetic conversion principle, enables secondary current to accurately reflect the change condition of primary current to be measured, and transmits the change condition to a secondary metering and controlling device; the product is directly installed in a 35kV solid cabinet and used for current and electric energy measurement and relay protection.
The invention is formed by vacuum casting of epoxy resin, has small volume, large creepage distance, high dynamic and thermal stability current, high metering precision, moisture resistance, condensation resistance and electricity larceny prevention, and can be widely applied to the transformation of a switch cabinet of a power system and a newly designed switch cabinet.
The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, extension, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.
Claims (8)
1. The current transformer for the solid cabinet is characterized by comprising an insulator (14) and a coil body sealed in the insulator (14), wherein primary wiring terminals are arranged at two ends of the insulator (14), a secondary wiring terminal (2) is arranged above the insulator (14), the insulator (14) is of an integral structure formed by pouring epoxy resin, and an aluminum powder layer (12) is sprayed on the outer surface of the insulator (14).
2. The current transformer for solid cabinets according to claim 1, characterized in that the primary terminal at one end of the insulator (14) is a contact type primary terminal (1) and the other end is a groove type primary terminal (15).
3. The current transformer for solid cabinets according to claim 2, characterized in that said groove-type primary connection terminals (15) are two and arranged in the lateral and vertical directions, respectively.
4. The current transformer for the solid cabinet according to claim 3, characterized in that the outer sides of the contact type primary connection terminal (1) and the groove type primary connection terminal (15) are provided with high voltage shielding nets.
5. The current transformer for the solid cabinet as claimed in claim 2, wherein a mounting flange is provided at the end of the groove-shaped primary wiring terminal (15) arranged in the vertical direction, and a low-voltage shielding net (6) is provided in the mounting flange.
6. The current transformer for the solid cabinet according to claim 1, wherein a secondary wiring cover (10) is arranged on the outer side of the secondary wiring terminal (2), and a semicircular wire outlet hole (11) is formed in the side surface of the secondary wiring cover (10).
7. The current transformer for the solid cabinet according to claim 1, wherein the coil body comprises an iron core (5), a primary winding (3) and a secondary winding (4), wherein the secondary winding (4) is wound on the iron core (5), the primary winding (3) is sleeved on the outer side of the secondary winding (4), and two ends of the primary winding are respectively connected with the primary wiring terminals.
8. The current transformer for a solid cabinet according to claim 1, characterized in that the insulator (14) is of square configuration.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811561836.3A CN111354538A (en) | 2018-12-20 | 2018-12-20 | Current transformer for solid cabinet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811561836.3A CN111354538A (en) | 2018-12-20 | 2018-12-20 | Current transformer for solid cabinet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111354538A true CN111354538A (en) | 2020-06-30 |
Family
ID=71196847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811561836.3A Pending CN111354538A (en) | 2018-12-20 | 2018-12-20 | Current transformer for solid cabinet |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111354538A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114242381A (en) * | 2022-01-18 | 2022-03-25 | 大连北方互感器集团有限公司 | Dry electromagnetic current mutual inductor |
-
2018
- 2018-12-20 CN CN201811561836.3A patent/CN111354538A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114242381A (en) * | 2022-01-18 | 2022-03-25 | 大连北方互感器集团有限公司 | Dry electromagnetic current mutual inductor |
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| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200630 |
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| WD01 | Invention patent application deemed withdrawn after publication |