CN211045239U - High-voltage isolation transformer with combined insulation structure - Google Patents

Abstract

The utility model provides a high-voltage isolation transformer with a combined insulating structure, belonging to the technical field of isolation transformers, comprising: a bottom plate, an insulating sleeve, a top plate and a voltage equalizing ring, wherein the insulating sleeve is coiled to form a column shape with an internal installation space, so the The installation space is suitable for arranging transformer components, and the pipe of the insulating bushing is suitable for accommodating insulating gas; the high-voltage isolation transformer of the present invention adopts the combination of gas insulation and solid insulation, wherein the solid insulation is the main part of the high-voltage isolation. Insulation and gas insulation are used as auxiliary insulation to improve the insulation characteristics of the transformer along the surface. The structure can be flexibly extended to voltage levels above 35kV. Compared with conventional dry-type transformers, it has higher dielectric strength, low partial discharge suppression, low noise, and high heat dissipation. It can realize the application of the isolation transformer under the DC high voltage of 100 kV and above, and meet the long-term reliable application under the DC voltage or the AC voltage.

Description

A high-voltage isolation transformer with combined insulation structure

technical field

The utility model relates to the technical field of isolation transformers, in particular to a high-voltage isolation transformer with a combined insulating structure.

Background technique

High-voltage isolation transformer refers to the isolation of the respective currents between the windings of the primary side (primary side) and the secondary side (secondary side) through certain insulation measures, so that the input winding and the output winding are electrically separated. transformer.

With the development of DC transmission design, some new devices have appeared in DC systems, such as DC circuit breakers. These devices are passive devices and require external energy supply, so isolation transformers are required. Since passive power equipment cannot obtain energy online through high potential, it needs to obtain energy from the low-voltage station power system through a high-voltage isolation transformer and then send it to a high potential. The high-voltage isolation transformer used must realize both power transmission and high-voltage isolation. Meet the high-voltage isolation energy requirements of passive power equipment.

The insulation structure of the prior art power transformers is generally designed with a single insulating medium, such as oil insulation, gas insulation or solid insulation. For example, dry-type transformers generally use epoxy resin and quartz sand to fill and cast solid insulation.

However, ordinary dry-type isolation transformers, which use epoxy solid insulating materials, have the problem of space charge accumulation under DC voltage, which is prone to discharge and lead to insulation breakdown. At the same time, the current application voltage of dry-type transformers is 35kV, the voltage level is low, and it is impossible to Applied to levels above 100 kV. The traditional oil transformer meets the requirements in performance, but there is a fire risk and does not meet the application conditions. In addition, the gas-insulated isolation transformer requires a gas pressure of 3-5 atmospheres. The transformer needs to be designed with a complex explosion-proof structure to achieve explosion-proof design. At the same time, there is also a risk of gas leakage. Once the gas leaks, the gas insulation performance will be reduced, and the transformer will also have insulation shock. Put on.

Utility model content

Therefore, the technical problem to be solved by the present invention is to overcome the defect that the isolation transformer in the prior art cannot be applied to the level of more than 100 kilovolts due to the single insulation design adopted by the insulation structure, thereby providing a high-voltage combined insulation structure. isolation transformer.

In order to solve the above-mentioned technical problems, the utility model provides a high-voltage isolation transformer with a combined insulating structure, including:

bottom plate;

The insulating sleeve is connected above the bottom plate, and the inside of the pipe is suitable for accommodating insulating gas; the insulating sleeve is coiled to form a cylindrical shape with an internal installation space, and the installation space is suitable for arranging transformer components;

a top plate, connected above the insulating sleeve;

A pressure equalizing ring is detachably connected to the top plate.

As a preferred solution, the transformer assembly includes at least one transformer module.

As a preferred solution, the transformer module includes:

bracket;

The low-voltage winding is arranged on the support, and its outlet end is connected with the support;

The high-voltage winding is arranged on the support and is associated with the low-voltage winding through a space magnetic field; the outlet end of the high-voltage winding extends upward and is suitable for protruding out of the top plate.

As a preferred solution, the transformer module further includes: a support insulator, which is vertically connected above the bracket and is suitable for connecting with the top plate.

As a preferred solution, there are a plurality of the supporting insulators, and at least one of the supporting insulators is provided with a capacitor and a resistance device inside to form a resistance-capacitance voltage equalizing device.

As a preferred solution, the transformer assembly includes a plurality of transformer modules that are connected in series up and down, and two adjacent transformer modules are connected at intervals through the supporting insulator.

As a preferred solution, the transformer assembly further comprises: a connecting busbar connected between the outlet end of the low voltage winding of the upper transformer module and the outlet end of the high voltage winding of the lower transformer module.

As a preferred solution, the support includes:

The support clip has two sets of left and right symmetry;

The iron core assembly is connected between the two sets of the support clips;

There are two low-voltage connecting plates, which are respectively vertically connected to the two sets of the supporting clips, and the low-voltage connecting plates are connected to the supporting clips at intervals through transverse insulators.

As a preferred solution, the high-voltage winding includes:

The insulating casting body is a hollow cylindrical structure and is suitable for horizontal arrangement;

an insulating terminal, having two juxtaposed on the side wall of the insulating casting body;

The high-voltage coil terminal is arranged in the insulating casting body and extends out of the insulating casting body through the insulating terminal part.

As a preferred solution, both ends of the insulating casting body are connected between the supporting clips through spacers.

The technical scheme of the utility model has the following advantages:

1. the high-voltage isolation transformer of the combined insulating structure provided by the utility model adopts the combined form of gas insulation and solid insulation, wherein the transformer assembly adopts solid insulation as the main insulation of high-voltage isolation, and gas insulation is adopted in the insulating bushing to improve the along-surface insulation characteristics of the transformer. Under the same voltage level and capacity, this design can greatly reduce the footprint of the transformer, making the structure more compact, and also conducive to reducing the cost of the transformer; in addition, the structure can be flexibly extended to voltage levels above 35kV , Compared with conventional dry-type transformers, it has higher dielectric strength, low partial discharge suppression, low noise, and high heat dissipation. Reliable application.

2. The high-voltage isolation transformer with combined insulating structure provided by the present invention can be composed of one or more transformer module units in internal structure, and the specific number can be adjusted according to the applied voltage level.

3. The high-voltage isolation transformer of the combined insulating structure provided by the present utility model, in the transformer module, at least one of the supporting insulators is provided with a capacitor and a resistance device inside to form a resistance-capacitance voltage equalizing device, so as to achieve a voltage equalization device under a temporary steady state voltage. equalizing pressure.

4. The high-voltage isolation transformer with combined insulation structure provided by the utility model adopts the design of multi-transformer module series structure, which can be applied in different voltage levels, and can be extended under different voltage forms and voltage levels. Low partial discharge characteristics; in DC system applications, space charge accumulation under DC can be avoided.

5. The high-voltage isolation transformer of the combined insulating structure provided by the utility model, the insulating casting body of the high-voltage winding is cast and packaged with solid insulating materials, which can realize high-voltage isolation, partial discharge suppression and space charge suppression; auxiliary gas insulation, insulating gas at a certain pressure. It can maintain the insulation isolation requirements of the transformer along the surface and reduce the requirements of external pollution on the creepage distance of the transformer along the surface.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the following descriptions The accompanying drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

FIG. 1 is a schematic three-dimensional structure diagram of a high-voltage isolation transformer with a combined insulating structure of the present invention.

FIG. 2 is a schematic three-dimensional structural diagram of an embodiment of the transformer assembly located inside the insulating bushing in FIG. 1 .

FIG. 3 is a schematic three-dimensional structural diagram of the combination of two transformer modules in FIG. 2 .

FIG. 4 is a schematic three-dimensional structure diagram of a transformer module.

FIG. 5 is a schematic three-dimensional structure diagram of a high-voltage winding.

Description of reference numbers:

1. Top plate; 2. Equalizing ring; 3. Insulating sleeve; 4. Bottom plate; 5. Bracket; 6. High voltage winding; 7. Supporting insulator; 8. Connecting busbar; 9. Supporting clip; 10. Iron core Components; 11, low voltage winding; 12, low voltage connection plate; 13, transverse insulator; 14, spacer; 15, insulating casting body; 16, insulating terminal; 17, high voltage coil terminal.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner" and "outer" The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, with a specific orientation. Therefore, it should not be construed as a limitation on the present invention.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a connectable connection. Detachable connection, or integral connection; may be mechanical connection or electrical connection; may be direct connection or indirect connection through an intermediate medium, or internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as there is no conflict with each other.

This embodiment provides a high-voltage isolation transformer with a combined insulating structure. As shown in FIG. 1, it is an external structure of the high-voltage isolation transformer, including: a top plate 1, a voltage equalizing ring 2, an insulating sleeve 3 and a bottom plate 4. The above structures are connected by form a whole. The insulating sleeve 3 is connected above the bottom plate 4 , the top plate 1 is connected above the insulating sleeve 3 , and the pressure equalizing ring 2 is detachably connected to the top plate 1 through bolts .

The insulating sleeve 3 is coiled to form a cylindrical shape with an installation space inside, and the installation space is suitable for arranging transformer components. The single tube of the insulating sleeve 3 is suitable for filling with insulating gas, and the insulating gas can be the insulating gas commonly used in power equipment at present: such as sulfur hexafluoride (SF6), a mixture of SF6 and other gases, nitrogen, etc.; The pressure can be slightly positive pressure, that is, slightly higher than atmospheric pressure, or it can be several times higher than atmospheric pressure.

As shown in FIG. 2, the internal structure of the high-voltage isolation transformer, that is, the transformer assembly arranged in the installation space of the insulating bushing 3, includes a plurality of transformer modules connected in series up and down in sequence, wherein two adjacent ones of the The transformer modules are connected at intervals by supporting insulators 7 . In addition, as an alternative embodiment, the transformer assembly may also have only one transformer module.

As shown in FIG. 3 , the transformer module includes: a bracket 5 , a low-voltage winding 11 and a high-voltage winding 6 arranged on the bracket 5 . The outgoing end of the high-voltage winding 6 extends upward, and the outgoing end of the high-voltage winding 6 at the top extends upward from the top plate 1 to serve as the general external outlet connection terminal of the high-voltage isolation transformer. The low-voltage winding 11 is fixed on one arm of the iron core assembly 10, and is coaxially arranged with the high-voltage winding 6, so as to associate the low-voltage winding 11 and the high-voltage winding 6 through a space magnetic field; the iron core assembly 10 is not only a part of the bracket 5, but also a supporting member connected between adjacent brackets 5.

When the transformer module has a plurality of upper and lower series connected in series, it also includes support insulators 7; the support insulators 7 can be arranged in four symmetrical groups, and the four groups of support insulators 7 are connected vertically above the bracket 5 in a rectangular shape, respectively, The support insulator 7 can be used to connect two transformer modules, and can also be used to connect between the bracket 5 and the top plate 1 . When the supporting insulator 7 is located above the topmost bracket 5, the top end of the supporting insulator 7 is used for connecting with the top plate 1; when the supporting edge is located on the bracket 5 of the middle layer, the top end of the supporting insulator 7 is used for each layer Spacer connections between transformer modules.

Between the transformer modules of each layer, there is also a connecting busbar 8 for connecting the outgoing end of the low voltage winding 11 in the upper transformer module and the outgoing end of the high voltage winding 6 in the lower transformer module.

Among the four groups of supporting insulators 7 in each layer, the two supporting insulators 7 located on the side of the bracket 5 close to the low-voltage winding 11 are provided with capacitance and resistance devices to form a resistance-capacitance voltage equalizing device.

As shown in FIG. 4 , the bracket 5 includes two sets of left-right symmetrical support clips 9 , an iron core assembly 10 connected between the two sets of support clips 9 , and a core assembly 10 connected between the two sets of the support clips respectively. The two low-voltage connecting plates 12 on the 9, and the low-voltage connecting plates 12 are connected to the support clip 9 at intervals through the transverse insulator 13, and the two outgoing ends of the low-voltage winding 11 are respectively connected to the bracket 5. The two low-voltage connection boards 12 are connected.

As shown in FIG. 5 , the high-voltage winding 6 includes: an insulating casting body 15 , an insulating terminal 16 and a high-voltage coil terminal 17 , the insulating casting body 15 is a hollow cylindrical structure, and is suitable for horizontal arrangement on the support 5 , During installation, both ends of the insulating casting body 15 are connected between the two groups of support clips 9 of the bracket 5 through the spacer 14 ; the insulating terminals 16 are arranged side by side on the side wall of the insulating casting body 15 The high-voltage coil terminals 17 are arranged in the insulating casting body 15 and partially extend out of the insulating casting body 15 through the insulating terminals 16 . The insulating casting body 15 is the insulation isolation of the high-voltage winding 6 from the low-voltage winding 11 and the iron core potential, and is also the structural support body of the high-voltage winding 6 . The insulating casting body 15 is an inner hollow and insulating cylinder, the high-voltage coil is sleeved on the insulating casting body 15, and the high-voltage coil is wound with a plurality of concentric turns. The outer periphery of the terminal 17 protruding from the insulating sleeve 3 is wrapped with an insulating terminal 16 , thereby forming the high-voltage winding 6 as a whole.

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. And the obvious changes or changes derived from this are still within the protection scope of the present invention.

Claims (10)

1. A high-voltage isolation transformer with a combined insulation structure is characterized by comprising:

a base plate (4);

an insulating sleeve (3) connected above the bottom plate (4) and adapted to contain an insulating gas therein; the insulating sleeve (3) is coiled to form a cylinder shape with an inner installation space, and the installation space is suitable for arranging a transformer assembly;

the top plate (1) is connected above the insulating sleeve (3);

and the equalizing ring (2) is detachably connected to the top plate (1).

2. The high voltage isolation transformer of claim 1, wherein the transformer assembly comprises at least one transformer module.

3. The high voltage isolation transformer of claim 2, wherein the transformer module comprises:

a bracket (5);

the low-voltage winding (11) is arranged on the bracket (5), and the outlet end of the low-voltage winding is connected with the bracket (5);

the high-voltage winding (6) is arranged on the bracket (5) and is associated with the low-voltage winding (11) through a space magnetic field; the outlet end of the high-voltage winding (6) extends upwards and is suitable for extending out of the top plate (1).

4. The high voltage isolation transformer of claim 3, wherein the transformer module further comprises: and the supporting insulator (7) is vertically connected above the bracket (5) and is suitable for being connected with the top plate (1).

5. The high voltage isolation transformer according to claim 4, wherein said supporting insulators (7) are provided in plurality, at least one of said supporting insulators (7) being internally provided with capacitive and resistive means to constitute resistive-capacitive voltage grading means.

6. The high-voltage isolation transformer of claim 4, wherein the transformer assembly comprises a plurality of transformer modules connected in series one above the other, and two adjacent transformer modules are connected at intervals through the supporting insulator (7).

7. The high voltage isolation transformer of claim 6, wherein the transformer assembly further comprises: and the connecting bus bar (8) is connected between the outlet end of the low-voltage winding (11) of the upper-layer transformer module and the outlet end of the high-voltage winding (6) of the lower-layer transformer module.

8. The high voltage isolation transformer according to claim 3, wherein the bracket (5) comprises:

the supporting clamping pieces (9) are provided with two groups which are symmetrical left and right;

a core assembly (10) connected between the two sets of support clamps (9);

the two low-voltage connecting plates (12) are respectively vertically connected to the two groups of supporting clamping pieces (9), and the low-voltage connecting plates (12) are connected with the supporting clamping pieces (9) at intervals through transverse insulators (13).

9. The high voltage isolation transformer according to claim 8, wherein the high voltage winding (6) comprises:

an insulating casting body (15) having a hollow cylindrical structure and adapted to be arranged laterally;

an insulating terminal (16) having two terminals arranged in parallel on a side wall of the insulating cast body (15);

a high voltage coil terminal (17) disposed within the insulating casting (15) and partially protruding out of the insulating casting (15) through the insulating terminal (16).

10. The high voltage isolation transformer according to claim 9, wherein the insulating casting (15) is connected at both ends between the support clamps (9) by means of spacers (14).

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