CN113903575A

CN113903575A - High-impedance transformer with built-in reactor

Info

Publication number: CN113903575A
Application number: CN202111178536.9A
Authority: CN
Inventors: 安振; 高辉; 王炳光; 刘欢; 李国旗
Original assignee: Wujiang Transformer Co Ltd
Current assignee: Wujiang Transformer Co Ltd
Priority date: 2021-10-10
Filing date: 2021-10-10
Publication date: 2022-01-07
Anticipated expiration: 2041-10-10
Also published as: CN113903575B; WO2023056657A1

Abstract

The invention discloses a high impedance transformer with a built-in reactor, which comprises: three coil assemblies arranged in a mode that the central point is positioned at the vertex of the regular triangle and a fixing assembly used for connecting the coil assemblies; the fixing assembly comprises an upper pressing plate positioned above the coil assembly, an upper clamping piece positioned on the upper pressing plate, a lower supporting plate positioned below the coil assembly, a lower clamping piece positioned below the lower supporting plate and three rod-shaped tensioning mechanisms penetrating through the coil assembly, one end of each rod-shaped tensioning mechanism penetrates through the upper pressing plate and is fixedly connected with the upper clamping piece, and the other end of each rod-shaped tensioning mechanism penetrates through the lower supporting plate and is fixedly connected with the lower clamping piece. The invention adopts the built-in series reactor, and the reactor bodies are arranged in a shape like a Chinese character 'pin', thereby obviously reducing the weight, having high production efficiency, low cost and reliable performance. And the processing is simple, the noise of the product is reduced, the volume and the mass are small, and the movement and the installation are convenient. And moreover, the arrangement of the shape like the Chinese character 'pin' is adopted, the mutual balance of three-phase magnetic flux leakage can be guaranteed, the overheating phenomenon is avoided, the loss is reduced, and the potential safety hazard can be reduced.

Description

High-impedance transformer with built-in reactor

Technical Field

The invention relates to the field of transformers and reactors, in particular to a high-impedance transformer with a built-in reactor.

Background

In order to realize safe operation of the power grid, the short-circuit resistance of the transformer must be improved, and the change rate and the short-circuit current value of the voltage of the power grid are reduced, wherein the two parameters are determined by the short-circuit impedance value of the transformer, namely, the impedance value of the transformer is increased when the change rate and the short-circuit current value of the voltage of the power grid are reduced. For a transformer, a reactor is usually connected in series with a low-voltage coil of the transformer to replace most of equipment impedance, so that the purpose of large-impedance operation is achieved. Generally, for the convenience of installation of a reactor, three coils of the reactor are arranged in a straight line.

However, since the main body of the series reactor and the main body of the transformer share one oil tank, when the reactor coils are arranged in a straight line, the reactor coils occupy larger space, namely the oil tank needs to be expanded, the occupied area of the reactor coils is larger, and the production and transportation cost is higher. And when three coils of reactor are the style of calligraphy and arrange, the three-phase magnetic leakage just can not be balanced, just can cause the structure loss big just, and the structure generates heat, still can produce harmful gas simultaneously.

Disclosure of Invention

The invention overcomes the defects that the three coils of the reactor in the prior art occupy large space and three-phase magnetic leakage cannot be balanced when the three coils are arranged in a straight line, provides the high-impedance transformer with the built-in reactor, and adopts the technical scheme that: a high-impedance transformer with a built-in reactor, comprising: the reactor is characterized by comprising three coil assemblies which are arranged in a mode that the central point is positioned at the vertex of a regular triangle and a fixing assembly used for connecting the coil assemblies;

the fixing assembly comprises an upper pressing plate positioned above the coil assembly, an upper clamping piece positioned on the upper pressing plate, a lower supporting plate positioned below the coil assembly, a lower clamping piece positioned below the lower supporting plate and three rod-shaped tensioning mechanisms penetrating through the coil assembly, one end of each rod-shaped tensioning mechanism penetrates through the upper pressing plate and is fixedly connected with the upper clamping piece, and the other end of each rod-shaped tensioning mechanism penetrates through the lower supporting plate and is fixedly connected with the lower clamping piece.

In a preferred embodiment of the present invention, the fixing assembly further includes an upper magnetic screen plate and a lower magnetic screen plate, the upper magnetic screen plate is disposed between the upper pressing plate and the upper clamp, and the lower magnetic screen plate is disposed between the lower supporting plate and the lower clamp.

In a preferred embodiment of the present invention, the upper magnetic shield is composed of a silicon steel strip and an insulating layer disposed on a surface of the silicon steel strip, and the lower magnetic shield is composed of a silicon steel strip and an insulating layer disposed on a surface of the silicon steel strip, and the silicon steel strip is electrically connected to a ground plate.

In a preferred embodiment of the present invention, the coil assembly includes a supporting cylinder sleeved on the corresponding rod-shaped tensioning mechanism and a coil wound on the outer surface of the supporting cylinder, and the supporting cylinder is an insulating mechanism formed by a paper board wound outside a wood frame.

In a preferred embodiment of the invention, a rod-shaped tensioning mechanism is also arranged in the region surrounded by three coil assemblies.

In a preferred embodiment of the invention, the upper pressure plate is a circular plate covering all coil assemblies, the upper clamping piece and the upper pressure plate are concentric, three support arms extend from the center position to the directions of the three rod-shaped tensioning mechanisms, and the whole structure is in a three-fork shape;

the lower supporting plate is a circular plate covering the bottoms of all the coil assemblies, the lower clamping piece and the lower supporting plate are concentric, three support arms extend from the central position to the direction of the three rod-shaped tensioning mechanisms, and the whole body is of a three-fork-shaped structure.

In a preferred embodiment of the present invention, the fixing assembly further includes a plurality of insulating spacers disposed at the bottom of the lower plate.

In a preferred embodiment of the invention, the reactor is located at one end of a three-phase in-line transformer, the coils correspond to three phase coils in the transformer one by one, specifically, an a-phase coil, a B-phase coil and a C-phase coil, a connecting lead led out from the coils is connected to a low-voltage coil in the transformer corresponding to the phase through a lug and a copper bar in sequence, and the three coils are arranged in an XYZ three-dimensional space.

In a preferred embodiment of the invention, in an XYZ three-dimensional space, a copper bar of a transformer three-phase low-voltage coil in the X direction is connected into a reactor, an A-phase coil is close to the transformer, a connecting lead of the A-phase coil is in the X direction and is connected into a Y-direction copper bar through a lug, a connecting lead of a B-phase coil is in the Y direction and is connected into an X-direction-to-Y-direction copper bar through a lug, a connecting lead of a C-phase coil is in the Z direction and is connected into the X-direction-to-Z-direction copper bar through the lug.

In a preferred embodiment of the invention, the rod-shaped tensioning mechanism is composed of a plurality of screw rods which are uniformly distributed on the circumference of a same circle, and the center of the circle is the center of the coil assembly corresponding to the rod-shaped tensioning mechanism.

The invention solves the defects in the background technology, and has the following beneficial effects:

(1) the invention adopts the built-in series reactor, and the reactor body is arranged in a shape like a Chinese character 'pin', so the weight is obviously reduced, the production efficiency is high, the cost is low, and the performance is reliable; and the processing is simple, the noise of the product is reduced, the volume and the mass are small, and the movement and the installation are convenient. In addition, the arrangement of the Chinese character 'pin' shape is adopted, the mutual balance of three-phase magnetic leakage can be guaranteed, the overheating phenomenon is avoided, the loss is reduced, and the potential safety hazard can be reduced;

(2) the upper clamping piece and the lower clamping piece are in a three-fork shape in structural appearance, and have the technical characteristics of balanced stress, high material utilization rate and low structural loss, the upper clamping piece and the lower clamping piece are made of metal pieces, the mechanical strength is enhanced, and the rod-shaped tensioning mechanism is fixedly connected with the upper clamping piece or the lower clamping piece, so that the fixing strength is stronger;

(3) the invention has simple structure, high production efficiency, small occupied area and low cost, and is suitable for the environment with strict requirements on space size.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings of the embodiments can be obtained according to the drawings without creative efforts.

Fig. 1 is a front view of a high impedance transformer with a built-in reactor according to an embodiment of the present invention;

fig. 2 is a top view of a high impedance transformer with a built-in reactor according to an embodiment of the present invention;

fig. 3 is a schematic diagram of connection between a coil of the reactor and a coil of the transformer according to an embodiment of the present invention.

The reference numerals are as follows: 01. a high-voltage coil; 02. a low-voltage coil; 10. a coil assembly; 101. a support cylinder; 102. a coil; 1021. a lead wire; 103. a copper sheet; 20. a fixing assembly; 201. an upper pressure plate; 202. an upper clamp; 203. an upper magnetic screen panel; 204. a rod-shaped tensioning mechanism; 2041. a screw; 205. a lower supporting plate; 206. a lower clamp; 207. a lower magnetic screen panel; 301. cushion blocks; 302. a positioner; 401. a lug plate; 402. copper bars; 403. a wooden piece; 404. the flexible wiring piece can be disassembled.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, the present invention will be further described in detail with reference to the accompanying drawings and the detailed description, wherein the drawings are simplified schematic drawings and only the basic structure of the present invention is illustrated schematically, so that only the structure related to the present invention is shown, and it is to be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be considered limiting of the scope of the present application. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the invention, the meaning of "a plurality" is two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art through specific situations.

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Referring to fig. 3, a high-impedance transformer with a built-in reactor includes a low-voltage side coil 02, a high-voltage side coil 01, and a reactor correspondingly connected to the low-voltage side coil 02, wherein, referring to fig. 1, the reactor includes: three coil blocks 10 arranged such that the center points thereof are located at the vertices of a regular triangle, and a fixing block 20 for connecting the coil blocks 10.

That is to say, in the high-impedance transformer with a built-in reactor of the present invention, the three coils 102 are arranged in a zigzag manner, the three-phase magnetic flux leakage is balanced, and no other potential safety hazard is caused by local overheating inside the transformer. Compared with the linear arrangement, the arrangement mode is tighter, namely, the occupied volume is smaller, and the oil tank of the transformer does not need to be expanded.

Referring to fig. 1-2, the fixing assembly 20 includes an upper pressing plate 201 located above the coil assembly 10, an upper clamp 202 located on the upper pressing plate 201, an upper magnetic screen panel 203 disposed between the upper pressing plate 201 and the upper clamp 202, a lower supporting plate 205 located below the coil assembly 10, a lower clamp 206 located below the lower supporting plate 205, a lower magnetic screen panel 207 disposed between the lower supporting plate 205 and the lower clamp 206, and three rod-shaped tightening mechanisms 204 penetrating through the coil assembly 10, wherein one end of each rod-shaped tightening mechanism 204 penetrates through the upper pressing plate 201 and the upper magnetic screen panel 203 in sequence, and is finally fixedly connected to the upper clamp 202, and the other end penetrates through the lower supporting plate 205 and the lower magnetic screen panel 207 in sequence, and is finally fixedly connected to the lower clamp 206.

It can be seen that the coil assembly 10 includes the support cylinder 101 and the coil 102, and the fixing assembly 20 is a plate-type fixing member provided with fixing and clamping the coil 102 at both the upper end and the lower end of the coil 102, and fixed with a rod-shaped tightening mechanism 204 therebetween to connect them into a complete whole. The upper magnetic screen plate 203 and the lower magnetic screen plate 207 are arranged for magnetic shielding, so that leakage magnetic flux is reduced, and overheating of a transformer oil tank and the like caused by magnetic lines of force generated after the coil 102 is electrified into the transformer oil tank are avoided.

Specifically, the upper magnetic shield 203 is composed of a silicon steel strip and an insulating layer disposed on the surface of the silicon steel strip, the lower magnetic shield 207 is composed of a silicon steel strip and an insulating layer disposed on the surface of the silicon steel strip, and the silicon steel strip is electrically connected to a grounding plate. The silicon steel material has high magnetic permeability and good magnetic shielding effect. The invention uses the upper magnetic screen 203 and the lower magnetic screen 207 for magnetic shielding, has simple structure, high production efficiency, small occupied area and low cost, and is suitable for the environment with strict requirements on space size.

With continued reference to fig. 1-2, the coil assembly 10 includes a supporting cylinder 101 disposed on the corresponding rod-shaped tensioning mechanism 204, and a coil 102 wound on the outer surface of the supporting cylinder 101, wherein the coil 102 is arranged in such a manner that the central point is located at the vertex of the regular triangle, and the supporting cylinder 101 is an insulating mechanism formed by winding a paper board on the outer surface of a wooden framework.

A rod-shaped tensioning mechanism 204 is also arranged in the region surrounded by the three coil arrangements 10. The rod-shaped tightening mechanism 204 is composed of a plurality of screws 2041, the screws 2041 are uniformly distributed on the circumference of the same circle, and the center of the circle is the center of the coil assembly 10 corresponding to the rod-shaped tightening mechanism 204.

Here, the screw 2041 in the rod-like tightening mechanism 204 may be conductive or non-conductive according to the magnetic flux characteristics, and the connection mode of the upper and lower metal parts is determined according to the distribution of magnetic lines of force, so as to form a reasonable magnetic circuit and a grounding system, thereby avoiding the occurrence of commutation and overheating.

Referring to fig. 1-2, the upper pressing plate 201 is a circular plate covering all the coil assemblies 10, the upper clamping piece 202 is concentric with the upper pressing plate 201, three support arms extend from the central position to the direction of the three rod-shaped tensioning mechanisms 204, and the whole body is in a three-fork structure; the lower supporting plate 205 is a circular plate covering the bottoms of all the coil assemblies 10, the lower clamping piece 206 is concentric with the lower supporting plate 205, three support arms extend from the central position to the direction of the three rod-shaped tensioning mechanisms 204, and the whole body is in a three-fork-shaped structure. The upper clamping piece 202 and the lower clamping piece 206 are in a three-fork shape, and have the technical characteristics of balanced stress, high material utilization rate and low structural loss. Moreover, the material of the upper clip 202 and the lower clip 206 is metal, so that the mechanical strength is enhanced, and the rod-shaped tightening mechanism 204 is fixedly connected with the upper clip 202 and the lower clip 206, so that the fixing strength is stronger.

Referring to fig. 1-2, the fixing assembly 20 further includes a plurality of insulating spacers 301 disposed at the bottom of the lower plate. The insulating cushion block 301 is made of a flexible material, so that when the transformer works, vibration of the transformer body is reduced, working noise caused by the transformer body and the ground is reduced, and the bottom of the fixing component 20 is also provided with the positioner 302, so that the three coils 102 of the reactor can be more accurately assembled, and the three magnetic fluxes leakage can be more balanced.

Referring to fig. 3, the reactor is located at one end of the three-phase linear arrangement transformer, coils 102 of the reactor correspond to coils of three phases in the transformer one by one, specifically, coils of a phase a, coils of a phase B, and coils of a phase C, a connecting lead 1021 led out from the coils 102 of the reactor is connected to low-voltage coils of the corresponding phases in the transformer sequentially through a lug plate 401 and a copper bar 402, and the three coils 102 are arranged in an XYZ three-dimensional space. Specifically, in an XYZ three-dimensional space, a reactor is connected to a copper bar 402 of a three-phase low-voltage coil of the transformer from an X direction, an A-phase coil is close to the transformer, a connecting lead 1021 of the A-phase coil is in the X direction, the connecting lead 1021 of the A-phase coil is connected to the Y-direction copper bar 402 through a lug plate 401, a connecting lead 1021 of a B-phase coil is in the Y direction, the connecting lead 1021 of the B-phase coil is connected to the X-direction-to-Y-direction copper bar 402 through the lug plate 401, a connecting lead 1021 of a C-phase coil is in the Z direction, and the connecting lead is connected to the X-direction-to-Z-direction copper bar 402 through the lug plate 401.

Here, the copper bar 402 is fixed by a wooden piece 403. And the reactor and the transformer are movably connected through a detachable soft lug 404. The reactor body and the transformer body are connected in a detachable mode, so that the reactor body and the transformer body are more convenient to detach and transport.

In addition, the magnetic shield of the reactor and other metal components have different potentials from the tank potential due to the electric field of the coil 102. Although the potential difference between them is not large, the discharge will continue through a small insulation distance. Since the discharge breaks down the oil and it is impossible to confirm whether the transformer is in a normal state during testing and operation, the core and its metallic structure must be grounded. The upper magnetic screen plate 203 is connected with the upper clamping piece 202 through the copper sheet 103, the lower magnetic screen plate 207 is connected with the lower clamping piece 206 through the copper sheet 103, and the upper clamping piece 202 and the lower clamping piece 206 are connected together through the rod-shaped tensioning mechanism 204 with low magnetic steel. The reactor is integrally arranged at the bottom of the transformer oil tank through a damping structure and is finally connected with the transformer main body through a connecting lead 1021, so that one-point grounding is ensured, and the normal work of the transformer and the reactor is also ensured.

Compared with a reactor body structure with a built-in series reactor, the reactor provided by the invention has the advantages of obviously reduced volume and weight, high production efficiency, low cost and reliable performance. And the processing is simple, the noise of the product is reduced, the volume and the mass are small, and the movement and the installation are convenient. And moreover, the arrangement of the shape like the Chinese character 'pin' is adopted, the mutual balance of three-phase magnetic flux leakage can be guaranteed, the overheating phenomenon is avoided, the loss is reduced, and the potential safety hazard can be reduced.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A high-impedance transformer with a built-in reactor, comprising: the reactor is characterized by comprising three coil assemblies which are arranged in a mode that the central point is positioned at the vertex of a regular triangle and a fixing assembly used for connecting the coil assemblies;

2. The high-impedance transformer of a built-in reactor according to claim 1, characterized in that: the fixing assembly further comprises an upper magnetic screen plate and a lower magnetic screen plate, the upper magnetic screen plate is arranged between the upper pressing plate and the upper clamping piece, and the lower magnetic screen plate is arranged between the lower supporting plate and the lower clamping piece.

3. The high-impedance transformer of a built-in reactor according to claim 2, characterized in that: the upper magnetic screen plate is composed of a silicon steel strip and an insulating layer arranged on the surface of the silicon steel strip, the lower magnetic screen plate is composed of a silicon steel strip and an insulating layer arranged on the surface of the silicon steel strip, and the silicon steel strip is electrically connected with a grounding sheet which is grounded.

4. The high-impedance transformer of a built-in reactor according to claim 1, characterized in that: the coil assembly comprises a supporting cylinder and a coil, wherein the supporting cylinder is arranged on the rod-shaped tensioning mechanism in a sleeved mode, the coil is wound on the outer surface of the supporting cylinder, and the supporting cylinder is an insulating mechanism formed by winding paper boards outside a wood framework.

5. The high-impedance transformer of a built-in reactor according to claim 1, characterized in that: the rod-shaped tensioning mechanism is also arranged in the area surrounded by the three coil assemblies.

6. The high-impedance transformer of a built-in reactor according to claim 1, characterized in that: the upper clamping piece and the upper pressing plate are concentric, three support arms extend from the center to the three rod-shaped tensioning mechanisms, and the whole body is of a three-fork-shaped structure;

the lower supporting plate is a circular plate covering the bottoms of all the coil assemblies, the lower clamping piece and the lower supporting plate are concentric, three support arms extend from the central position to the directions of the three rod-shaped tensioning mechanisms, and the whole body is of a three-fork-shaped structure.

7. The high-impedance transformer of a built-in reactor according to claim 1, characterized in that: the fixing assembly further comprises a plurality of insulating cushion blocks arranged at the bottom of the lower clamping plate.

8. The high-impedance transformer of a built-in reactor according to claim 1, characterized in that: the reactor is positioned at one end of the three-phase linear arrangement transformer, the coils correspond to coils of three phases in the transformer one by one, specifically an A-phase coil, a B-phase coil and a C-phase coil, a connecting lead led out from the coils is connected to a low-voltage coil of the corresponding phase in the transformer through a lug plate and a copper bar in sequence, and the three coils are arranged in an XYZ three-dimensional space.

9. The high-impedance transformer of an internal reactor according to claim 8, characterized in that: in an XYZ three-dimensional space, a copper bar of a three-phase low-voltage coil of a transformer in the X direction is connected into a reactor, an A-phase coil is close to the transformer, a connecting lead of the A-phase coil is in the X direction and is connected into a Y-direction copper bar through a lug plate, a connecting lead of a B-phase coil is in the Y direction and is connected into an X-direction-to-Y-direction copper bar through the lug plate, a connecting lead of a C-phase coil is in the Z direction and is connected into the X-direction-to-Z-direction copper bar through the lug plate.

10. The high impedance transformer of an internal reactor according to claim 1, wherein the rod-like tightening mechanism is composed of a plurality of threaded rods, the threaded rods are uniformly distributed on the circumference of a same circle, and the center of the circle is the center of the coil assembly corresponding to the rod-like tightening mechanism.