Ground screen electrostatic ring structure for testing transformer
By setting a ground screen electrostatic ring structure in the test transformer, the electromagnetic interference and tip discharge problems between coils are solved, and the insulation reliability and test accuracy are improved.
Patent Information
- Application Number
- CN202422818559.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2034-11-19
AI Technical Summary
In the test transformer, the electromagnetic interference between the low-voltage coil and the high-voltage coil of the transformer affects the test accuracy, and there is a tip discharge problem at the end of the ground screen, which affects the insulation reliability.
A ground screen is set between the low-voltage coil and the high-voltage coil, with low-voltage support bars and high-voltage support bars on both sides of the ground screen. The copper tape runs through the inside of the ground screen and is wrapped with the copper foil tape. The outside is covered with folded paper grooves and cardboard. The copper strands are welded and grounded to the outer shell to form an electrostatic ring structure to prevent tip discharge.
The electric field distribution at the end of the ground screen is improved, the R corner radius of the electrode is increased, the insulation reliability of the end of the ground screen is improved, electromagnetic interference is prevented, and the accuracy and reliability of the test are guaranteed.
Smart Images
Figure CN223462103U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of test transformers, and particularly relates to a ground screen static ring structure for a test transformer. BACKGROUND
[0002] With the vigorous development of electrical engineering technology in China, more and more electrical equipment is widely used. After leaving the factory, delivery or overhaul, electrical equipment should be subjected to AC temperature rise test to actually examine the overcurrent bearing capacity of the equipment. Test transformers are basic test equipment for AC test of various electrical products, electrical components, insulating materials and the like for users such as power plants, power supply bureaus and research institutions, and are used to examine the heat resistance and insulation level of products, find insulation defects of the tested product, measure the overcurrent capacity and ensure the working performance of the tested product.
[0003] In a test transformer, the low-voltage coil and the high-voltage coil are physically isolated but coupled by a magnetic field, and in electrical terms, electromagnetic interference is generated in the test, thereby affecting the accuracy of the test. In order to enhance the electrical reliability between the low-voltage coil and the high-voltage coil, a ground screen is arranged between the two coils, the ground screen itself is composed of 0.05mm thick copper foil strips, and there are sharp corners at the ends. During the test or operation of the transformer, the sharp corners will cause sharp discharge to the oil gap. CONTENT OF THE INVENTION
[0004] In order to solve the above problems, the present application provides a ground screen static ring structure for a test transformer. The inside of the transformer is provided with a low-voltage coil, a high-voltage coil and a voltage regulating coil. A ground screen is arranged between the low-voltage coil and the high-voltage coil. The two sides of the ground screen are respectively provided with a plurality of low-voltage support bars and high-voltage support bars. One end of the ground screen is vertically penetrated and led out and provided with a copper strip. The copper strip is arranged inside the ground screen and is wound around and connected with a copper foil strip. The copper foil strip is arranged horizontally and parallel inside the ground screen. The outer side of the copper foil strip is covered with a flange paper groove. The two sides of the flange paper groove are covered with paper boards. A cable paper is arranged between the smooth surface of the flange paper groove and the paper board. The outer side of the copper strip extending out of the outer end of the ground screen is provided with a copper strand which is wound and welded. The outer side of the position where the copper strand is welded with the copper strip is provided with a crepe paper. The outer side of the crepe paper is connected with a support plate through a slot arranged on the inner side of the support plate. The structure of the ground screen lead-out wire winding into a static ring is economical and simple to manufacture, and does not need to increase the main air channel or add an angle ring to improve the electric field distribution at the end of the ground screen, increase the electrode R corner radius at the end and improve the insulation reliability of the end of the ground screen.
[0005] The transformer is a winding type combined transformer, and the transformer is externally provided with a transformer shell. The inside of the transformer is annularly wound with a low-voltage coil, a high-voltage coil and a voltage regulating coil. The low-voltage coil, the high-voltage coil and the voltage regulating coil are sequentially overlapped and externally covered in a wrapped manner from inside to outside. The low-voltage coil and the high-voltage coil are annularly and spacedly provided with a ground screen. The inner wall of the transformer shell is fixedly connected with a copper stranded wire for grounding.
[0006] The low-voltage support and the high-voltage support are both vertically shaped strip supports. The low-voltage support and the high-voltage support are both provided with notches at one end of the side edges of the ground screen. The notches are internally provided with copper strips. When the ground screen is placed between the low-voltage coil and the high-voltage coil of the body, the copper stranded wire is wound on the notches of the low-voltage support. Then, the high-voltage support is assembled, and the notches of the high-voltage support also hold the copper stranded wire. In this way, the copper stranded wire forms a ring, which functions as an electrostatic ring.
[0007] The paperboard is rectangularly shaped and is covered on both sides. The inside of the paperboard between the two sides is provided with a plurality of horizontally and parallelly arranged fluted paper slots. The inside of the fluted paper slots is provided with copper foil strips in a clamped manner. One end of the fluted paper slots is vertically and penetratively provided with a copper strip. The covered paperboard prevents the end of the ground screen from discharging and ensures the insulation reliability of the transformer.
[0008] The copper strip is a cylindrical connecting copper strip. The lower end of the copper strip is internally embedded in the ground screen. The bottom of the copper strip is externally and woundly connected with the copper foil strip. The top end of the copper strip is protrusively provided on the outside of the ground screen. The copper strip is externally and weldedly provided on the outside of the ground screen with a copper stranded wire. The copper stranded wire is a grounding lead copper wire. One end of the copper stranded wire is weldedly connected with the copper strip. The other end of the copper stranded wire is fixedly connected with the transformer shell. The electrostatic shield is a plurality of non-closed copper sheets arranged between the low-voltage coil and the high-voltage coil as a shielding layer. The copper sheets are connected with the shell for grounding by a lead wire to prevent other external electromagnetic interference.
[0009] Advantages:
[0010] The electrostatic shield is a plurality of non-closed copper sheets arranged between the low-voltage coil and the high-voltage coil as a shielding layer. The copper sheets are connected with the shell for grounding by a lead wire to prevent other external electromagnetic interference.
[0011] The covered paperboard prevents the end of the ground screen from discharging and ensures the insulation reliability of the transformer.
[0012] The copper strip and the copper stranded wire are welded when the ground screen is made. The copper stranded wire is single-sidedly wrapped with 2mm corrugated paper, and the overall diameter is 10mm. When the ground screen is placed between the low-voltage coil and the high-voltage coil of the body, the copper stranded wire is wound on the notches of the low-voltage support. Then, the high-voltage support is assembled, and the notches of the high-voltage support also hold the copper stranded wire. In this way, the copper stranded wire forms a ring, which functions as an electrostatic ring.
[0013] The structure that the ground screen lead winding forms electrostatic ring is more economical and simple to make, and does not need to increase the main air channel or add an angle ring to improve the electric field distribution of the ground screen end, increase the electrode R radius of the end, and improve the insulation reliability of the ground screen end. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 It is a transformer sectional view of the ground screen electrostatic ring structure for a test transformer.
[0015] Figure 2 It is a ground screen electrostatic ring side view of the ground screen electrostatic ring structure for a test transformer.
[0016] Figure 3 It is a ground screen electrostatic ring surface partial sectional view of the ground screen electrostatic ring structure for a test transformer.
[0017] Figure 4 It is a ground screen electrostatic ring A-A sectional view of the ground screen electrostatic ring structure for a test transformer.
[0018] In the figure, 1 is a transformer shell, 2 is a low-voltage coil, 3 is a high-voltage coil, 4 is a voltage regulating coil, 5 is a copper strip, 6 is a low-voltage support strip, 7 is a ground screen, 8 is a high-voltage support strip, 9 is a copper stranded wire, 10 is a paperboard, 11 is a cable paper, 12 is a flanged paper slot, and 13 is a copper foil tape. DETAILED DESCRIPTION
[0019] In order to deepen the understanding of the present application, the present application will be further described in combination with examples and drawings. The examples are only used to explain the present application and do not constitute a limitation on the protection scope of the present application.
[0020] The transformer shell 1, the low-voltage coil 2, the high-voltage coil 3, the voltage regulating coil 4, the copper strip 5, the low-voltage support strip 6, the ground screen 7, the high-voltage support strip 8, the copper stranded wire 9, the paperboard 10, the cable paper 11, the flanged paper slot 12, and the copper foil tape 13.
[0021] As shown in Figure 1 , 2 , 3, 4.
[0022] The utility model relates to a kind of ground screen 7 electrostatic ring structure for test transformer, the inside of transformer is equipped with low voltage coil 2, high voltage coil 3 and voltage regulating coil 4, low voltage coil 2 and high voltage coil 3 are separatedly equipped with ground screen 7, the surface of ground screen 7 both sides is equipped with several low voltage stay 6 and high voltage stay 8, one end of the ground screen 7 is vertically penetrated and led out and is equipped with copper band 5, the copper band 5 is arranged inside ground screen 7 and is wound and is connected with copper foil band 13, the copper foil band 13 is horizontally parallel and is arranged in the inside of ground screen 7, the outside of copper foil band 13 is covered with fluted paper groove 12, the surface of the fluted paper groove 12 both sides is covered with paperboard 10, cable paper 11 is arranged between the smooth surface of fluted paper groove and paperboard 10, the outside surface of the outer end of copper band 5 extending out of ground screen 7 is wound and welded and is equipped with copper stranded wire 9, the position of copper stranded wire 9 and copper band 5 welding outside is equipped with corrugated paper, the outside of the corrugated paper is connected with support plate by being clamped in the slot of the inside of support plate, transformer is winding type combination transformer, the outside of transformer is equipped with transformer shell 1, the inside of transformer is annularly wound and is equipped with low voltage coil 2, high voltage coil 3 and voltage regulating coil 4, the low voltage coil 2, high voltage coil 3 and voltage regulating coil 4 are sequentially overlapped and covered from inside to outside, the annular interval of the low voltage coil 2 and high voltage coil 3 is equipped with ground screen 7, the inner wall of transformer shell 1 is fixed and connected with copper stranded wire 9 ground, the shape of low voltage stay 6 and high voltage stay 8 is vertical strip stay, the opposite inside of one end between low voltage stay 6 and high voltage stay 8 at the side edge of ground screen 7 is equipped with slot, the inside of the slot is clamped and is equipped with copper band 5, the shape of paperboard 10 is rectangular two-side covered paperboard 10, the inside between two-side paperboard 10 is horizontally parallel and is equipped with several fluted paper grooves 12, the inside of the fluted paper groove 12 is clamped and is equipped with copper foil band 13, one end of fluted paper groove 12 is vertically penetrated and is equipped with copper band 5, the shape of copper band 5 is cylindrical connection copper band 5, the lower end of copper band 5 is embedded in the inside of ground screen 7, the bottom outside of copper band 5 is wound and connected with copper foil band 13, the top end of copper band 5 protrudes and is arranged outside ground screen 7, copper band 5 is welded and is equipped with copper stranded wire 9 on the outside surface of the outer end of ground screen 7, copper stranded wire 9 is ground type lead-in copper wire, one end of copper stranded wire 9 is welded and connected with copper band 5, the other end of copper stranded wire 9 is fixedly connected with transformer shell 1.
[0023] Implementation example;
[0024] In the production item ground screen 7, copper band 5 and 162 copper stranded wire 9 are welded, copper stranded wire 9 is single-side wrapped with 2mm corrugated paper, and the overall diameter is 10mm.In the process of placing ground screen 7 between low voltage coil 2 and high voltage coil 3 of the body, copper stranded wire 9 is wound on the slot of low voltage stay 6, and then high voltage stay 8 is assembled, and the slot of high voltage stay 8 also clamps copper stranded wire 9, so that copper stranded wire 9 forms a ring and plays the role of electrostatic ring.
[0025] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A ground screen static ring structure for a test transformer, the inside of the transformer being provided with a low-voltage coil, a high-voltage coil, and a regulating coil, a ground screen being provided between the low-voltage coil and the high-voltage coil in a partitioned manner, and a plurality of low-voltage stay bars and a plurality of high-voltage stay bars being provided on both side surfaces of the ground screen, characterized in that, The one end of the ground screen vertically penetrates and leads out the copper band, the copper band is internally wound and connected with the copper foil band, the copper foil band is horizontally and parallelly arranged in the ground screen, the outer side of the copper foil band is externally covered by the flanged paper groove, the both sides of the flanged paper groove are covered by the paper board, the cable paper is arranged between the smooth surface of the flanged paper groove and the paper board, the outer side of the copper band extending out of the outer end of the ground screen is externally welded with the copper stranded wire, the outer side of the copper stranded wire welded with the copper band is externally provided with the corrugated paper, and the outer side of the corrugated paper is connected with the supporting plate through the slot in the inner side of the supporting plate. 2. The ground screen electrostatic ring structure for a test transformer according to claim 1, characterized by The transformer is a winding type combined transformer, the transformer is externally provided with a transformer shell, the transformer is internally annularly wound with a low-voltage coil, a high-voltage coil and a voltage regulating coil, the low-voltage coil, the high-voltage coil and the voltage regulating coil are sequentially overlapped and externally covered from inside to outside, and the low-voltage coil and the high-voltage coil are annularly and spacedly provided with a ground screen.
3. The ground screen electrostatic ring structure for a test transformer according to claim 2, characterized by The inner wall of the transformer shell is fixedly connected with the copper stranded wire grounding.
4. The ground screen electrostatic ring structure for a test transformer according to claim 1, wherein The low-voltage supporting strip and the high-voltage supporting strip are both vertically strip-shaped supporting strips, one end of the low-voltage supporting strip and the high-voltage supporting strip opposite to the inner side of the ground screen side edge is provided with a slot, and the inner side of the slot is connected with the copper band.
5. The ground screen electrostatic ring structure for a test transformer of claim 1, wherein, The paper board is a rectangular two-side covered paper board, a plurality of flanged paper grooves are horizontally and parallelly arranged in the inner part between the two paper boards, the inner part of the flanged paper groove is connected with the copper foil band, and one end of the flanged paper groove vertically penetrates the copper band.
6. The ground screen electrostatic ring structure for a test transformer of claim 1, wherein, The copper band is a cylindrical connecting copper band, the lower end of the copper band is internally embedded in the ground screen, the bottom outer side of the copper band is wound with the copper foil band, the top end of the copper band protrudes out of the ground screen, and the copper band externally welded with the copper stranded wire is arranged on the outer end of the ground screen.
7. The ground screen electrostatic ring structure for a test transformer of claim 1, wherein, The copper stranded wire is a grounding type lead-in copper wire, one end of the copper stranded wire is welded with the copper band, and the other end of the copper stranded wire is fixedly connected with the transformer shell.