CN111768958A - Transformer bushing - Google Patents

Abstract

The present application discloses a transformer bushing, comprising: an insulating tube, which is axially arranged as a hollow structure; a capacitor core, which includes a current-carrying rod passing through the insulating tube, and a current-carrying rod located inside the insulating tube and wound in sequence on the outside of the current-carrying rod The multi-layer insulating layer and the multi-layer capacitive screen, wherein, one end of the current-carrying rod extending out of the insulating tube is fixedly connected with the first terminal and electrically connected with the first terminal; the end screen joint is connected with the capacitor core. The last screen is electrically connected for grounding the last screen when the transformer bushing is running. The transformer bushing provided by the present application has a simple structure, can save costs, reduce production processes and improve production efficiency.

Description

Transformer bushing

technical field

The present application relates to the field of power transmission technology, in particular to a transformer bushing.

Background technique

The transformer bushing is a high-voltage device widely used in power systems. It is fixedly installed on the casing of the transformer. One end is exposed outside the transformer and is electrically connected to external conductors such as cables. The leads are electrically connected so that the output current of the transformer is directed to an external conductor such as a cable through the transformer bushing, or the current in the external conductor such as the cable is directed to the transformer through the transformer bushing.

At present, the capacitive bushing is divided into oil-paper capacitive type and tape-paper capacitive type, and oil-paper capacitive type is divided into cable-through type and conduit current-carrying type according to the current-carrying structure. The conduit current-carrying type is based on the connection method between the terminal and the casing It is divided into direct type and rod type.

The inventor of the present application found in long-term research that the existing oil-paper capacitive bushing has a complex structure and many components, which easily leads to poor contact between the components.

SUMMARY OF THE INVENTION

The purpose of the present application is to provide a transformer bushing, which can save costs, reduce production processes and improve production efficiency.

In order to achieve the above purpose, the technical solution adopted in the present application is to provide a transformer bushing, comprising: an insulating tube, which is arranged as a hollow structure along the axial direction; a capacitor core, which includes a current-carrying rod passing through the insulating tube and a A multilayer insulating layer and a multilayer capacitive screen wound in sequence inside the insulating tube and outside the current-carrying rod, wherein the end of the current-carrying rod extending out of the insulating tube is fixed to the first terminal connected and electrically connected with the first connection terminal; the end shield connector is electrically connected with the end shield in the capacitor core, and is used for grounding the end shield when the transformer bushing is running.

Wherein, it also includes: an oil conservator, which is fixed on one end of the insulating pipe and communicated with the insulating pipe, wherein the one end of the current-carrying rod passes through the oil conservator from the insulating pipe, and is connected with the insulating pipe. The first connection terminal located outside the oil conservator is fixedly connected.

Wherein, the current-carrying rod is arranged in a hollow structure along the axial direction, and the current-carrying rod is located inside the insulating tube and/or the oil conservator and is not covered by the insulating layer and the capacitive screen Several through holes are arranged on the side wall.

Wherein, it also includes: a first end cover, covering the other end of the current-carrying rod extending out of the insulating tube, and a second terminal is fixed on the side of the first end cover away from the current-carrying rod , the first end cover is electrically connected to the current-carrying rod and the second connection terminal.

It also includes: a round nut, which is tightly sleeved on the periphery of the current-carrying rod and covers the other end of the insulating tube, and at the same time the first end cover abuts against the round nut on the side away from the insulating tube. an end face; a gasket, the gasket is a ring structure, and the inner and outer annular surfaces of the gasket are both non-circular surfaces, wherein the gasket is clamped on the current-carrying rod and the round nut In between, the current-carrying rod is matched with the inner ring surface, and the round nut is matched with the outer ring surface.

Wherein, the inner ring surface and the outer ring surface of the washer are both non-circular surfaces. Specifically, the outer ring surface is provided with a plurality of first snap grooves, and the circular nut is arranged on the inner wall of the washer. There is a first clamping block corresponding to the first clamping groove; and/or, the inner annular surface is provided with a plurality of second clamping blocks, and the current-carrying rod is facing the outer wall of the gasket. There is a second card slot corresponding to the second card block.

Wherein, the insulating pipe includes a first sub-insulating pipe and a second sub-insulating pipe connected by flanges, the end of the first sub-insulating pipe not connected with the flange is connected to the oil conservator, and the first sub-insulating pipe The round nut is connected to one end of the two sub-insulating pipes which is not connected with the flange.

Wherein, the end screen joint includes: a grounding column, the grounding column is a conductive member, and includes a first end connected with the lead wire of the end shield and a second end opposite to the first end, Wherein, when the grounding column is inserted into the mounting hole on the flange, the second end of the grounding column is away from the mounting hole; the insulating member is sleeved on the periphery of the grounding column , used to isolate the hole wall of the mounting hole and the outer wall of the grounding column; the pressing piece includes an annular plate sleeved on the periphery of the insulating member and a peripheral wall extending from the inner circumference of the annular plate, wherein when When the pressing member is assembled on the flange base by passing through the first bolt on the annular plate so that the grounding column and the insulating member are positioned in the mounting hole, the pressing member is electrically connected with the flange, and the peripheral wall of the pressing member is far away from the flange; a grounding seat covers the pressing member and accommodates the second end of the grounding column in In the grounding seat, the pressing member and the grounding column are electrically connected.

Wherein, the insulating member is sleeved on the periphery of the grounding column through a casting process, and a plurality of first grooves are provided on the outer wall of the grounding column and the insulating member.

Wherein, the lead wire of the last screen is wound on the second bolt, and the first end of the grounding column is provided with a second groove corresponding to the second bolt, so that the second The bolt is detachably assembled in the second groove, so as to realize the connection between the lead wire of the end screen and the first end of the grounding column.

The beneficial effects of the present application are: the end of the current-carrying rod in the capacitor core that extends out of the insulating tube is fixedly connected to the first connection terminal and electrically connected to the first connection terminal, so that the current in the transformer can pass through the current-carrying terminal. The rod flows to the first connection terminal, or the current in the first connection terminal can flow to the transformer through the current-carrying rod. The bushing generally includes a coiled tube in the capacitor core and a current-carrying rod passing through the coiled tube. Its structure is simple, it can save costs, and there is no need to make insulation between the coiled tube and the current-carrying rod. , which can reduce the production process and improve the production efficiency. In addition, the transformer bushing in the present application also includes a terminal screen connector electrically connected to the terminal screen in the capacitor core, which can not only ensure the normal operation of the transformer bushing, but also facilitate the high-voltage test of the transformer bushing.

At the same time, the transformer bushing in this application is also provided with a gasket between the current-carrying rod and the round nut. The gasket has a ring structure, and its inner and outer toroid surfaces are both non-circular, which can prevent the current-carrying rod from being trapped in the transformer. turn in the casing.

In addition, the end screen joint of the transformer bushing in this application specifically includes a grounding column, an insulating member, a pressing member and a grounding seat, which can measure the capacitance and dielectric loss of the transformer bushing during the high-voltage test, and can measure the electrical capacity and dielectric loss of the transformer bushing during the high-voltage test. During normal operation, ground the end screen to ensure that the field strength of the capacitor core is evenly distributed. At the same time, compared with the prior art, the present application does not need to set small porcelain pieces, the structure is simple and compact, and when assembling, it is only necessary to assemble the grounding column, the insulating piece, and the pressing piece in sequence, and then the pressing piece is fixed on the first bolt by the first bolt. Flange, and then set the grounding seat cover on the pressing part, which is convenient and fast.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort. in:

1 is a schematic cross-sectional structure diagram of an embodiment of the transformer bushing of the present application;

Fig. 2 is the enlarged schematic diagram of A place in Fig. 1;

Fig. 3 is the enlarged schematic diagram at B in Fig. 2;

Fig. 4 is the enlarged schematic diagram of C place in Fig. 1;

5 is a schematic diagram of an explosion structure of a current-carrying rod, a round nut and a gasket in an application scenario;

FIG. 6 is a schematic diagram of the front structure of the gasket in an application scenario;

FIG. 7 is a schematic diagram of the front structure of the gasket in another application scenario;

Fig. 8 is the enlarged schematic diagram of D place in Fig. 1;

Fig. 9 is the enlarged schematic diagram of E place in Fig. 8;

FIG. 10 is a schematic cross-sectional structure diagram of the grounding column and the insulating member in FIG. 9;

FIG. 11 is a partial cross-sectional structural schematic diagram of the flange in FIG. 9 .

Detailed ways

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

Referring to FIG. 1 and FIG. 2 , FIG. 1 is a schematic cross-sectional structure diagram of an embodiment of the transformer bushing of the present application, and FIG. 2 is an enlarged schematic diagram of the position A in FIG. 1 . The transformer bushing in this application may be an oil-paper capacitive transformer bushing, or other types of bushings, which are not limited herein. The transformer bushing 1000 is arranged on the transformer (not shown in the figure), specifically fixed on the casing of the transformer, one end of which extends out of the transformer, and the other end extends into the interior of the transformer, and is used to guide the current in the transformer to the cable, etc. External electrical conductors, or direct current from external electrical conductors such as cables to a transformer. In this embodiment, the transformer bushing 1000 includes an insulating tube 1010 , a capacitor core 1020 , and an end screen joint 1030 .

The insulating tube 1010 is axially arranged as a hollow structure, that is, a hollow tube. The insulating tube 1010 is formed by winding fibers such as glass fibers, aramid fibers, etc., or manufactured by other processes such as molding.

The capacitor core 1020 includes a current-carrying rod 1021 passing through the insulating tube 1010, and a multi-layer insulating layer and a multi-layer capacitive screen that are located inside the insulating tube 1010 and are wound in sequence on the outside of the current-carrying rod 1021. For the sake of clarity in FIG. 1 , The multi-layer insulating layer and the multi-layer capacitive screen as a whole are designated by the reference numeral 1022. At the same time, one end 10211 of the current-carrying rod 1021 extending out of the insulating tube 110 is fixedly connected to the first connection terminal 1040 and electrically connected to the first connection terminal 1040 . Specifically, the first connection terminal 1040 is used to connect external conductors such as cables. When the current-carrying rod 1021 is electrically connected to the first connection terminal 1040, the external conductor such as the cable connected to the current-carrying rod 1021 and the first connection terminal 1040 is electrically connected. connect. In this embodiment, the current-carrying rod 1021 in the capacitor core 1020 is specifically used for current-carrying, so that the current in the transformer flows into the first connection terminal 1040 through the current-carrying rod 1021 , and then flows into the first connection terminal 1040 . An external conductor such as a cable, or the current in the external conductor such as a cable flows to the transformer through the first connection terminal 1040 and the current-carrying rod 1021 in sequence. Therefore, compared with the prior art, the transformer bushing includes not only the coiled tube in the capacitor core, but also the current-carrying rod which is inserted into the coiled tube and used for current-carrying. It is simple, can save costs, and does not need to perform insulation production between the rolled tube and the current-carrying rod, which can reduce the production process and improve the production efficiency.

The end screen connector 1030 is electrically connected with the end screen (not shown in the figure) in the capacitor core 1020, that is, the outermost capacitive screen in the capacitor core 1020, and is used to ground the end screen when the transformer bushing 1000 is running to ensure the transformer. The field intensity distribution inside the bushing 1000 is uniform, and the capacity and dielectric loss of the transformer bushing 1000 are measured during the high-voltage test.

It can be seen from the above content that, on the one hand, the transformer bushing 1000 in the present application directly uses the current-carrying rod 1021 in the capacitor core 1020 to transmit the current between the transformer and external conductors such as cables, that is, to carry current, and has a simple structure. The production process can be reduced and the production efficiency can be improved; on the other hand, the end screen joint 1030 is provided, which can not only ensure the normal operation of the transformer bushing 1000, but also facilitate the high-voltage test.

In an application scenario, one end 10211 of the current-carrying rod 1021 is directly and fixedly connected to the first connection terminal 1040, and there is no other connecting element between the two, so that the current transmitted between the current-carrying rod 1021 and the first connection terminal 1040 is not It will pass through other components, which can reduce the transition of the current during the transmission process. In addition, the direct connection of the current-carrying rod 1021 to the first terminal 1040 can also reduce the number of components in the transformer bushing 1000 and ensure good contact between components. Of course, in other application scenarios, as long as the current-carrying rod 1021 and the first terminal 1040 can be electrically connected, one end 10211 of the current-carrying rod 1021 can also be fixedly connected to the first terminal 1040 through other connecting elements, which is not limited here. .

Since the current-carrying rod 1021 in the present application needs to transmit the current between the external conductor such as the cable and the transformer, the current-carrying rod 1021 needs to carry a larger current during the operation of the transformer bushing 1000, thereby generating more heat . In order to dissipate the heat generated by the current-carrying rod 1021 in time, in an application scenario, the insulating tube 1010 is filled with transformer oil (not shown). When the transformer bushing 1000 is working, convection occurs between the higher temperature transformer oil and the lower temperature transformer oil in the insulating tube 1010, thereby dissipating the heat generated by the current-carrying rod 1021 and preventing its temperature from being too high. In this application scenario, in order that the insulating tube 1010 can be filled with transformer oil under any temperature and operating conditions, continue referring to FIG. 1 and FIG. 2 , the transformer bushing 1000 further includes an oil conservator 1050 . When the volume of the transformer oil in the insulating tube 1010 expands or shrinks according to the air temperature and operating conditions, the oil conservator 1050 can play the role of adjusting the oil volume.

Specifically, the oil conservator 1050 is fixed on one end 10101 of the insulating pipe 1010 and communicates with the insulating pipe 1010 , and at the same time, one end 10211 of the current-carrying rod 1021 passes through the oil conservator 1050 from the insulating pipe 1010 , and communicates with the first end outside the oil conservator 1050 . A connection terminal 1040 is fixedly connected. When the volume of the transformer oil in the insulating tube 1010 expands, the excess transformer oil in the insulating tube 1010 flows to the oil conservator 1050, that is, the oil conservator 1050 plays the role of oil storage at this time, and when the volume of the transformer oil in the insulating tube 1010 shrinks At this time, the transformer oil in the oil conservator 1050 flows to the insulating pipe 1010, that is, the oil conservator 1050 plays the role of replenishing oil at this time.

In this application scenario, continue to refer to FIG. 1 and FIG. 2 , in order to further improve the heat dissipation performance of the current-carrying rod 1021 , the current-carrying rod 1021 is also a hollow tube, that is, the current-carrying rod 1021 is arranged as a hollow structure in the axial direction, and the current-carrying rod 1021 is located in the insulating Several through holes 10213 are provided on the side wall 10212 inside the pipe 1010 and/or the oil conservator 1050 and not covered by the insulating layer and the capacitive screen, wherein the several through holes 10213 can be located only in the insulating pipe 1010 or the oil conservator 1050, it can also be distributed in the insulating pipe 1010 and the oil conservator 1050 at the same time. By arranging the through holes 10213, the transformer oil can be circulated on the inner and outer sides of the current-carrying rod 1021, and the temperature of the current-carrying rod 1021 can be significantly reduced. It is worth noting that due to the skin effect of the current, that is, when the current passes through the conductor, the current distribution on the conductor interface is uneven due to the induction effect. The current is almost only transmitted on the surface of the conductor, and almost no current passes through the inside of the conductor. Therefore, in this application scenario, the current-carrying rod 1021 is set as a hollow tube instead of a solid tube, which not only does not affect the current-carrying efficiency of the current-carrying rod 1021, but also saves money Material.

Continuing to refer to FIG. 1 , in order to further improve the fluidity of the transformer oil, several through holes 10213 are distributed on both sides of the area 10221 of the current-carrying rod 1021 covered by the insulating layer and the capacitive screen. By distributing the plurality of through holes 10213 on both sides of the area 10221 , the fluidity is stronger than that only on one side of the area 10221 , and the heat dissipation of the current-carrying rod 1021 can be accelerated.

Referring to FIGS. 1 , 2 and 3 , in an application scenario, the transformer bushing 1000 further includes a second end cover 1060 for covering one end 10211 of the current-carrying rod 1021 passing through the oil conservator 1050 . Specifically, before assembling the transformer bushing 1000, the second end cover 1060 does not cover the current-carrying rod 1021, so that the current-carrying rod 1021 can be pre-cleaned to ensure the cleanliness of the current-carrying rod 1021. 1000 after pre-cleaning, cover the second end cap 1060 on one end 10211 of the current-carrying rod 1021, at this time the second end cap 1060 is detachably or non-detachably connected to one end 10211 of the current-carrying rod 1021, for example, the second end The cover 1060 is connected with the current-carrying rod 1021 through screw connection, interference fit, or the second end cover 1060 is directly welded on the current-carrying rod 1021, so that when the transformer bushing 1000 operates normally, the second end cover 1060 can avoid the transformer Oil flows out or is invaded by outside moisture.

The inner side wall of one end 10211 of the current-carrying rod 1021 passing through the oil conservator 1050 has a step portion 10214 to form a first contact surface 10215 and a second contact surface 10216 that are in contact with the second end cover 1060 . Meanwhile, the second end cover 1060 includes a flat plate 1061 and a protruding post 1062 protruding from the surface 10611 of the flat plate 1061 . When the second end cap 1060 covers one end 10211 of the current-carrying rod 1021 , the protruding post 1062 extends into the current-carrying rod 1021 inside, the plate surface 10611 of the flat plate 1061 abuts the first contact surface 10215 , and the end surface 10621 of the protruding post 1062 abuts the second contact surface 10216 .

Referring to FIG. 1 and FIG. 4 , in an application scenario, the transformer bushing 1000 further includes a first end cover 1070 . The first end cap 1070 covers the other end 10217 of the current-carrying rod 1021 that extends out of the insulating tube 1010 , and at the same time, a second terminal 1080 is fixed on the side of the first end cap 1070 away from the current-carrying rod 1021 , and the first end cap 1070 The current-carrying rod 1021 is electrically connected to the second terminal 1080 . Specifically, the first end cover 1070 is connected with the current-carrying rod 1021 by means of threads, etc., the second connection terminal 1080 is located inside the transformer and is connected to the inner lead of the transformer, and the second connection terminal 1080 is fixed on the first end cover 1070, The first end cover 1070 is a conductive element, so that the output current of the transformer flows from the second connection terminal 1080 , the first end cover 1070 , and the current-carrying rod 1021 to the first connection terminal 1040 in sequence.

The transformer bushing 1000 further includes a round nut 1090 in order to cover the other end 10102 of the insulating tube 1010 , that is, the end of the insulating tube 1010 that is not connected to the oil conservator 1050 . The round nut 1090 is tightly sleeved on the periphery of the current-carrying rod 1021, and is fixed on the other end 10102 of the insulating tube 1010, so that the other end 10102 of the insulating tube 1010 is covered by the end face of the round nut 1090, and the first end cap 1070 is in contact with the The end face of the round nut 1090 on the side away from the insulating tube 1010 is fixedly connected to the round nut 1090 by means of bolts and other components. It should be noted that, in other embodiments, the round nut 1090 may not be provided, but the other end 10217 of the current-carrying rod 1021 and the other end 10102 of the insulating tube 1010 are simultaneously covered by the first end cap 1070 .

In an application scenario, continuing to refer to FIG. 4 , the round nut 1090 is provided with an oil drain port 1200 communicating with the insulating tube 1010 , and a matching oil drain plug 1210 is installed in the oil drain port 1200 . Specifically, when the transformer oil inside the insulating tube 1010 needs to be replaced, the oil drain plug 1210 is removed. At this time, since the oil drain plug 1210 is arranged at the end of the transformer bushing 1000, the transformer oil inside the insulating tube 1010 can flow cleanly.

The transformer bushing 1000 in the above embodiment adopts the current-carrying rod 1021 in the capacitor core 1020 to carry the current directly, and because the current flowing through the current-carrying rod 1021 is generally large, the external conductor such as the cable connected to the first terminal 1040 It is relatively thick, so a large torque force will be generated on the current-carrying rod 1021 during the operation of the transformer bushing 1000. In order to prevent the current-carrying rod 1021 from rotating when the transformer bushing 1000 is running, it is convenient for installation and fixation and is not easy to fail. Referring to FIGS. 4 and 5 , in another embodiment of the present application, the transformer bushing 1000 further includes a gasket 1100 .

The gasket 1100 is a ring structure, and the inner annular surface 1110 and the outer annular surface 1120 of the gasket 1100 are both non-circular surfaces, wherein the gasket 1100 is clamped between the current-carrying rod 1021 and the round nut 1090, and the current-carrying rod 1021 and the The inner ring surface 1110 of the washer 1100 is matched and fitted, and the round nut 1090 is matched and fitted with the outer ring surface 1120 of the washer 1100 . Since the outer annular surface 1120 and the inner annular surface 1110 of the gasket 1100 are both non-circular surfaces, and the gasket 1100 is clamped between the current-carrying rod 1021 and the round nut 1090, the gasket 1100 cannot rotate relative to the round nut 1090, Furthermore, the current-carrying rod 1021 matched with the gasket 1100 cannot rotate relative to the round nut 1090, and since the round nut 1090 is fixedly connected to the insulating tube 1010, the current-carrying rod 1021 cannot be rotated relative to the insulating tube 1010, that is, regardless of the external parts such as cables, etc. No matter how much torque is generated by the conductor, the current-carrying rod 1021 will not rotate in the transformer bushing 1000, and it is different from the sealing ring clamping method that is easy to fail and the thread tightening method that is inconvenient to operate in the prior art, The gasket 1100 is easy to install and fix. It should be noted that, in this embodiment, for the convenience of installation, the gasket 1100 is arranged between the round nut 1090 and the current-carrying rod 1021, but the application does not limit the position of the gasket 1100. In other embodiments, The gasket 1100 may also be disposed at other appropriate positions, such as between the current-carrying rod 1021 and the oil conservator 1050, between the current-carrying rod 1021 and the first end cover 1070, and so on.

In an application scenario, referring to FIG. 5 , FIG. 6 and FIG. 7 , the inner annular surface 1110 and the outer annular surface 1120 of the gasket 1100 are both non-circular surfaces. Specifically, the outer annular surface 1120 of the gasket 1100 is provided with several A slot 1121, the inner wall of the round nut 1090 facing the gasket 1100 is provided with a first clip 1092 corresponding to the first slot 1121, the outer ring surface 1120 of the gasket 1100 and the inner wall of the round nut 1090 pass through the first clip 1121. A card block 1092 and the first card slot 1121 are engaged with each other to match and fit, wherein the number of the first card slot 1121 and the first card block 1092 is correspondingly the same, which can be one, four or more, which is not done here. limit. In another application scenario, the inner annular surface 1110 and the outer annular surface 1120 of the gasket 1100 are both non-circular surfaces. Specifically, the inner annular surface 1110 of the gasket 1100 is provided with a plurality of second clamping blocks 1111 , the current-carrying rod 1021 The outer wall facing the gasket 1100 has a second slot 10218 corresponding to the second blocking block 1111. The inner annular surface 1110 of the gasket 1100 and the outer wall of the current-carrying rod 1021 pass through the second blocking block 1111 and the second blocking block 1111. The card slots 10218 are engaged with each other to match and fit, wherein the number of the second card slots 10218 and the second card blocks 1111 is correspondingly the same, which can be one, three, or more than four, which is not limited here. It should be noted that, in other application scenarios, the inner annular surface 1110 and the outer annular surface 1120 of the gasket 1100 are both non-circular surfaces. Specifically, the inner annular surface 1110 and the outer annular surface 1120 of the gasket 1100 may be elliptical surfaces. or other shaped surfaces. It should be noted that in this application, as long as the gasket 1100 is clamped between the current-carrying rod 1021 and the round nut 1090, the current-carrying rod 1021 cannot rotate freely. The shape of the torus 1120 is not limited.

In an application scenario, the cross section of the gasket 1100 perpendicular to its central axis is an axisymmetric figure (as shown in FIG. 6 ) or a center symmetrical figure (as shown in FIG. The overall force of the gasket 1100 is uniform and can withstand greater pressure.

In an application scenario, referring to FIG. 4 , further for the convenience of installation, the end face of the round nut 1090 on the side away from the insulating tube 1010 is provided with a third groove 1091 for the gasket 1100 to be inserted into. The round nut 1090 is in contact with the end surface of the washer 1100 . Specifically, during installation, first pass the current-carrying rod 1021 through the insulating tube 1010 and the round nut 1090, and then put the gasket 1100 into the third groove 1091 from the side of the round nut 1090 that is far from the insulating tube 1010, so that the The inner annular surface 1110 of the gasket 1100 is fitted with the current-carrying rod 1021 , and the outer annular surface 1120 is fitted with the round nut 1090 , which ultimately ensures that the current-carrying rod 1021 cannot rotate.

In an application scenario, referring to FIG. 1 , FIG. 2 , FIG. 4 and FIG. 8 , the insulating tube 1010 includes a first sub-insulating tube 1012 and a second sub-insulating tube 1013 connected by a flange 1011 , and the first sub-insulating tube 1012 is not One end connected to the flange 1011 , namely one end 10101 of the insulating tube 1010 , is connected to the oil conservator 1050 , and the other end 10102 of the second insulating tube 1013 not connected to the flange 1011 , that is, the other end 10102 of the insulating tube 1010 is connected to the round nut 1090 . When the transformer bushing 1000 is assembled to the transformer, the transformer bushing 1000 is fixed on the casing of the transformer through the flange 1011, while the second sub-insulating tube 1013 extends into the interior of the transformer, and the first sub-insulating tube 1012 extends out of the transformer the exterior. In order to protect the first sub-insulating tube 1012 extending outside, the outer periphery of the first sub-insulating tube 1012 is covered with an insulating layer 1014, and the insulating layer 1014 is an integral injection-molded silicone rubber shed, wherein the silicone rubber shed has good Hydrophobicity and anti-aging properties, high service life, and can effectively protect the first sub-insulating tube 1012.

In the above embodiment, by disposing the gasket 1100 with a ring structure between the current-carrying rod 1021 and the round nut 1090, and the inner ring surface 1110 and the outer ring surface 1120 of the gasket 1100 are both non-circular, the current-carrying rod can be ensured. 1021 cannot turn in transformer bushing 1000.

Referring to FIG. 9 to FIG. 11 , in another embodiment of the present application, the terminal screen connector 1030 specifically includes: a grounding column 1031 , an insulating member 1032 , a pressing member 1033 and a grounding base 1034 .

The grounding column 1031 is a conductive member, including a first end 10311 and a second end 10312 arranged oppositely. The first end 10311 of the grounding column 1031 is connected to the lead wire 1035 of the end screen (not shown in the figure), and when the lead wire When the 1035 is connected to the first end 10311, the grounding post 1031 and the lead wire 1035 are directly electrically connected. The part 10312 is far away from the mounting hole 10111; the insulating member 1032 is made of insulating material and is sleeved on the periphery of the grounding column 1031 to isolate the hole wall of the mounting hole 10111 and the outer wall of the grounding column 1031, that is, the setting of the insulating member 1032 There is no direct contact between the grounding column 1031 and the flange 1011; the pressing member 1033 includes an annular plate 10331 sleeved on the periphery of the insulating member 1032 and a peripheral wall 10332 extending from the inner circumference of the annular plate 10331. When the end screen joint 1030 is installed on the transformer When the sleeve 1000 is installed, the pressing member 1033 is assembled on the flange 1011 by passing through the first bolt 1036 on the annular plate 10331, so that the grounding column 1031 and the insulating member 1032 are positioned in the mounting hole 10111, and when the pressing member 1033 When fixed on the flange 1011, the pressing member 1033 is electrically connected to the flange 1011, and the peripheral wall 10332 of the pressing member 1033 is far away from the flange 1011; 10312 is accommodated in the grounding seat 1034, and further electrically connects the pressing member 1033 and the grounding column 1031, that is to say, when the grounding seat 1034 is covered on the pressing member 1033, the flange 1011, the grounding seat 1034 and the grounding column 1031 are connected. electrical connection. In an application scenario, the pressing member 1033 , the grounding base 1034 and the grounding post 1031 are the same as conductive parts, and the grounding post 1031 , the pressing member 1033 and the grounding base 1034 can all be made of materials such as aluminum, copper, stainless steel, etc. .

Among them, the end screen joint 1030 is pre-assembled before the normal operation of the transformer bushing 1000: the grounding column 1031 is inserted into the installation hole 10111 of the flange 1011, and its first end 10311 is connected with the lead wire 1035 of the end screen Then, the insulating member 1032 is sleeved on the outer side of the grounding column 1031, and further, the pressing member 1033 is fixed on the flange 1011 by the first bolt 1036, so that the grounding column 1031 and the insulating member 1032 are positioned in the mounting hole 10111, Finally, the grounding seat 1034 is covered on the pressing member 1033 so that the second end 10312 of the grounding post 1031 is accommodated in the grounding seat 1034, wherein the grounding seat 1034 can be covered on the pressing member 1034 by screw connection, interference fit connection, etc. on the fastener 1033. After the end screen joint 1030 is assembled, since the flange 1011 is grounded through the outer casing of the transformer (not shown), the grounding column 1031 is grounded through the grounding base 1034, the pressing piece 1033, the flange 1011 and the transformer casing in sequence, so as to realize The end screen is grounded to finally ensure that the field intensity distribution inside the transformer bushing 1000 is uniform. When the high voltage test is performed on the transformer bushing 1000, the grounding base 1034 is directly disassembled. At this time, since the grounding post 1031 and the flange 1011 are insulated by the insulating member 1032, the grounding post 1031 is no longer electrically connected with the flange 1011, and further The last screen is no longer grounded, and finally the capacitance and dielectric loss of the transformer bushing 1000 can be measured. After the high-voltage test is completed, the grounding seat 1034 can be assembled directly on the outside of the pressing member 1033 to ensure that the end screen is grounded again.

It can be seen from the above content that the end screen joint 1030 in this embodiment does not need to add a small porcelain piece, and has a simple structure, which is conducive to the miniaturization development of the transformer bushing 1000, and during assembly, the grounding post 1031 and the insulating piece 1032 are placed After the pressing member 1033 is sleeved in the installation hole 10111, the first bolt 1036 and the grounding seat 1034 can be directly tightened, and the assembly is convenient. In addition, during the high-voltage test, it is only necessary to disassemble and remove the grounding seat 1034. At this time, since the grounding seat 1034 and the grounding column 1031 are in a separated state, the staff can directly observe the situation of the grounding column 1031, so as to timely detect the defects in the grounding column 1031. Replace it to ensure grounding reliability.

In an application scenario, the grounding column 1031 is a cylinder, and in order to further reduce the volume of the end screen joint 1030 and ensure the sealing between the grounding column 1031 and the insulating member 1032 to avoid the intrusion of external moisture, dust, etc., the insulating member 1032 It is directly sleeved on the periphery of the grounding column 1031 through a casting process. When preparing the end screen joint 1030 , the grounding column 1031 is put into the machine, and insulating materials such as polytetrafluoroethylene or epoxy resin are directly poured on the outside of the grounding column 1031 to form the insulating member 1032 . The insulating member 1032 is formed by direct casting on the outside of the grounding column 1031, so that the contact between the grounding column 1031 and the insulating member 1032 is firm, the sealing performance is good, and the structure is compact, so there is no need to install a sealing ring, which can effectively reduce the end screen joint 1030. volume. Of course, in other application scenarios, the grounding column 1031 and the insulating member 1032 may also be independent of each other, and can be assembled together in a detachable manner, which is not limited here.

Further, in this application scenario, in order to increase the contact area between the grounding column 1031 and the insulating member 1032 to enhance the contact firmness between the two, referring to FIG. 10 , the outer wall of the grounding column 1031 and the insulating member 1032 is provided with several The first groove 10313. The first grooves 10313 are disposed around the grounding pillars 1031, and the number of the first grooves 10313 may be one, two, three or more, which is not limited herein. In addition, the present application does not limit the depth of the first groove 10313, which can be designed by designers according to specific requirements.

In an application scenario, in order to facilitate the replacement of the end screen connector 1030, continue to refer to FIG. 9 and FIG. 10, the lead wire 1035 of the end screen is wound on the second bolt 1037, correspondingly, the first end 10311 of the grounding column 1031 is provided with The second groove 10314 is correspondingly matched with the second bolt 1037 , wherein the second bolt 1037 is detachably assembled in the second groove 10314 . Specifically, one end of the lead wire 1035 of the end screen is welded on the end screen, and the other end is wound on the second bolt 1037, so that the second bolt 1037 is assembled in the second groove 10314 to realize the connection between the lead wire 1035 of the end screen and the ground. The connection between the first ends 10311 of the posts 1031 . In this application scenario, by wrapping the lead wire 1035 of the end panel around the second bolt 1037, when the end panel connector 1030 needs to be replaced due to aging, accidents, etc., the second bolt 1037 and the grounding post 1031 can be directly separated , easy to operate.

In an application scenario, referring to FIGS. 9 and 11 , the cross-sectional shape of the mounting hole 10111 in the axial direction thereof is stepped, so that the mounting hole 10111 forms a bearing surface 10112 in the axial direction thereof. When the pressing member 1033 is assembled on the flange 1011 , at least part of the insulating member 1032 is clamped between the annular plate 10331 and the bearing surface 10112 , thereby realizing the positioning of the insulating member 1032 and the grounding post 1031 in the mounting hole 10111 . That is to say, through the clamping between the pressing member 1033 and the bearing surface 10112 , the grounding column 1031 and the insulating member 1032 can no longer move along the axial direction of the mounting hole 10111 . In addition, in order to prevent the grounding post 1031 and the insulating member 1032 from moving along the radial direction of the mounting hole 10111, the periphery of the portion of the insulating member 1032 clamped by the pressing member 1033 and the bearing surface 10112 is fitted with the hole wall of the mounting hole 10111, so that the It is ensured that the grounding post 1031 and the insulating member 1032 cannot move in the installation hole 10111 , that is, they are positioned in the installation hole 10111 .

In an application scenario, referring to FIG. 9 and FIG. 10 , in order to ensure the electrical connection between the grounding post 1031 and the grounding base 1034 when the grounding post 1031 is accommodated in the grounding base 1034 , the second end 10312 of the grounding post 1031 is provided with a plurality of elastic metal For the sheet 1038 , the extension direction of the elastic metal sheet 1038 is the same as the axial direction of the grounding column 1031 .

The two ends of the elastic metal sheet 1038 are fixed on the grounding post 1031. When no external force is applied, the middle part 10381 of the elastic metal sheet 1038 expands in a direction away from the grounding post 1031. When the second end 1102 of the grounding post 1031 is accommodated in the grounding post When inside the seat 1034, the grounding seat 1034 exerts a force on the elastic metal sheet 1038, so that the plurality of elastic metal sheets 1038 can be elastically supported between the grounding column 1031 and the grounding seat 1034, thereby ensuring the connection between the grounding column 1031 and the grounding seat 1034 electrical connection. The plurality of elastic metal sheets 1038 are evenly spaced along the circumferential direction of the grounding post 1031 , and in order to maintain good elasticity after the grounding base 1034 is inserted and removed for many times, the elastic metal sheets 1038 are made of Made of materials with good mechanical properties such as copper.

Referring to FIGS. 1 to 9 , in another embodiment of the present application, the oil conservator 1050 is fixedly connected to the insulating tube 1010 and the current-carrying rod 1021 by glue, and the round nut 1090 is connected to the insulating tube 1010 by glue , the flange 1011 is respectively connected with the first insulating tube 1012 and the second insulating tube 1013 by means of glue. Specifically, the contact surface between the oil conservator 1050 and the insulating tube 1010 , the contact surface between the oil conservator 1050 and the current-carrying rod 1021 , the contact surface between the round nut 1090 and the insulating tube 1010 , and the contact between the flange 1011 and the first insulating tube 1012 Both the surface and the contact surface of the flange 1011 and the second insulating tube 1013 are provided with a glue-packing groove 1300 , and the glue-packing groove 1300 is filled with a glue-packing material for fixing, such as resin glue.

In order to further improve the sealing performance of the transformer bushing 1000 , in an application scenario, the transformer bushing 1000 further includes a plurality of sealing rings 1400 . Specifically, the contact surface between the second end cover 1060 and the current-carrying rod 1021 , the contact surface between the oil conservator 1050 and the insulating tube 1010 , the contact surface between the insulating tube 1010 and the round nut 1090 , and the contact between the current-carrying rod 1021 and the round nut 1090 surface, the contact surface between the first end cover 1070 and the round nut 1090, the contact surface between the first end cover 1070 and the current-carrying rod 1021, the contact surface between the grounding seat 1034 and the pressing member 1033, the contact surface between the pressing member 1033 and the insulating member 1032 A sealing ring 1400 is provided on the contact surface, the contact surface between the pressing member 1033 and the flange 1011 , and the contact surface between the insulating member 1032 and the bearing surface 10112 . The arrangement of the plurality of sealing rings 1400 can not only prevent the transformer oil in the insulating tube 1010 from leaking to the outside through the contact surfaces of the various components, causing oil leakage, but also prevent the intrusion of external moisture and pollutants. And part of the sealing ring 1400, such as the sealing ring 1400 between the insulating tube 1010 and the round nut 1090, and the sealing ring 1400 between the insulating tube 1010 and the oil conservator 1050, can also avoid the transformer oil and the glue filling material in the glue filling groove 1300. Contact, so as to avoid oil pollution and affect the electrical performance of the transformer bushing 1000 . Wherein, the cross section of the sealing ring 1400 along the axial direction may be in the shape of a circle, a rectangle or the like, which is not limited herein.

To sum up, in the present application, one end of the current-carrying rod in the capacitor core that extends out of the insulating tube is fixedly connected to the first connection terminal and electrically connected to the first connection terminal, so that the current in the transformer can flow to the first connection through the current-carrying rod. The terminal, or the current in the first connection terminal can flow to the transformer through the current-carrying rod, that is to say, the present application directly uses the current-carrying rod in the capacitor core to carry the current. Compared with the prior art, the transformer bushing generally includes The coiled tube in the capacitor core and the current-carrying rod passing through the coiled tube have a simple structure, can save costs, and do not need to perform insulation production between the coiled tube and the current-carrying rod, which can reduce the production process. Increase productivity. In addition, the transformer bushing in the present application also includes a terminal screen connector electrically connected to the terminal screen in the capacitor core, which can not only ensure the normal operation of the transformer bushing, but also be used for high-voltage test of the transformer bushing.

At the same time, the transformer bushing in this application is also provided with a gasket between the current-carrying rod and the round nut. The gasket has a ring structure, and its inner and outer toroid surfaces are both non-circular, which can prevent the current-carrying rod from being trapped in the transformer. turn in the casing.

In addition, the transformer bushing end screen joint in this application specifically includes a grounding column, an insulating member, a pressing member and a grounding seat, which can measure the capacitance and dielectric loss of the transformer bushing during the high-voltage test, and can measure the transformer bushing when the transformer bushing is normal. Ground the end screen during operation to ensure that the field strength of the capacitor core is evenly distributed. At the same time, compared with the prior art, the present application does not need to set small porcelain pieces, the structure is simple and compact, and when assembling, it is only necessary to assemble the grounding column, the insulating piece, and the pressing piece in sequence, and then the pressing piece is fixed on the first bolt by the first bolt. Flange, and then set the grounding seat cover on the pressing part, which is convenient and fast.

The above description is only an embodiment of the present application, and is not intended to limit the scope of the patent of the present application. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present application, or directly or indirectly applied to other related technologies Fields are similarly included within the scope of patent protection of this application.

Claims (10)

1. A transformer bushing, characterized in that, comprising: The insulating tube is arranged as a hollow structure along the axial direction; A capacitor core includes a current-carrying rod passing through the insulating tube, and a multi-layer insulating layer and a multi-layer capacitive screen that are located inside the insulating tube and are sequentially wound outside the current-carrying rod, wherein the current-carrying rod is One end of the rod extending out of the insulating tube is fixedly connected with the first terminal and electrically connected with the first terminal; The terminal screen connector is electrically connected to the terminal screen in the capacitor core, and is used for grounding the terminal screen when the transformer bushing is in operation. 2. The transformer bushing according to claim 1, further comprising: An oil conservator is fixed on one end of the insulating pipe and communicated with the insulating pipe, wherein the one end of the current-carrying rod passes through the oil conservator from the insulating pipe, and is connected with the oil conservator The first connection terminal outside the cabinet is fixedly connected. 3. The transformer bushing according to claim 2, wherein The current-carrying rod is arranged as a hollow structure along the axial direction, and the current-carrying rod is located inside the insulating pipe and/or the side wall of the oil conservator and is not covered by the insulating layer and the capacitive screen There are several through holes on it. 4. The transformer bushing of claim 2, further comprising: a first end cap, which covers the other end of the current-carrying rod extending out of the insulating tube, a second terminal is fixed on the side of the first end cap away from the current-carrying rod, and the first end cap is The end cap is electrically connected to the current-carrying rod and the second connection terminal. 5. The transformer bushing of claim 4, further comprising: A round nut is tightly sleeved on the periphery of the current-carrying rod and covers the other end of the insulating tube, while the first end cap abuts the end face of the round nut on the side away from the insulating tube; The gasket is of annular structure, and the inner and outer annular surfaces of the gasket are both non-circular surfaces, wherein the gasket is clamped between the current-carrying rod and the round nut , the current-carrying rod is matched with the inner ring surface, and the round nut is matched with the outer ring surface. 6. The transformer bushing according to claim 5, wherein the inner annular surface and the outer annular surface of the gasket are both non-circular surfaces and specifically include: The outer ring surface is provided with a plurality of first clamping grooves, and the inner wall of the round nut facing the gasket is provided with first clamping blocks corresponding to the first clamping grooves; and/or, The inner annular surface is provided with a plurality of second clamping blocks, and the outer wall of the current-carrying rod facing the gasket is provided with second clamping grooves corresponding to the second clamping blocks. 7. The transformer bushing of claim 5, wherein The insulating pipe includes a first sub-insulating pipe and a second sub-insulating pipe that are connected by flanges. The end of the first sub-insulating pipe that is not connected to the flange is connected to the oil conservator, and the second The round nut is connected to the end of the insulating tube which is not connected with the flange. 8. The transformer bushing according to claim 7, wherein the end screen joint comprises: A grounding column, the grounding column is a conductive member, comprising a first end connected to the lead wire of the terminal screen and a second end opposite to the first end, wherein when the grounding column is inserted When in the mounting hole on the flange, the second end of the grounding post is away from the mounting hole; an insulating member sleeved on the periphery of the grounding column and used for isolating the hole wall of the installation hole and the outer wall of the grounding column; A pressing piece includes an annular plate sleeved on the periphery of the insulating piece and a peripheral wall extending from the inner circumference of the annular plate, wherein, when the pressing piece is assembled on the annular plate through a first bolt passing through the annular plate When the grounding column and the insulating member are positioned in the mounting hole on the flange base, the pressing member is electrically connected to the flange, and the peripheral wall of the pressing member is far away from the flange; The grounding seat covers the pressing member and accommodates the second end of the grounding column in the grounding seat, thereby electrically connecting the pressing member and the grounding column. 9. The transformer bushing of claim 8, wherein The insulating member is sleeved on the periphery of the grounding column through a casting process, and a plurality of first grooves are provided on the outer wall of the grounding column that is in contact with the insulating member. 10. The transformer bushing of claim 8, wherein The lead wire of the last screen is wound on the second bolt, and the first end of the grounding column is provided with a second groove corresponding to the second bolt, so that the second bolt can be It is disassembled and assembled in the second groove, so as to realize the connection between the lead wire of the end screen and the first end of the grounding column.

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