CN103050240B - A kind of Transformer Bushing Tap signal ejector - Google Patents

Abstract

The invention provides a transformer bushing end screen signal lead-out device, which is used to lead out the leakage current on the end screen lead-out line of the capacitive bushing end screen, which includes: The outer joint on the interface; the protective sleeve connected to the outer joint, and the protective sleeve is provided with a wire hole; the conductive rod connected to the protective sleeve through an elastic insulator, and the end of the conductive rod close to the installation hole is along the circumferential direction At least two connecting petals are arranged to form insertion holes for matching with the lead-out wires of the last screen, and the elastic insulating member is sheathed on the connecting petals. The size of the insertion hole can change with the insertion depth of the lead wire of the last screen, and the elastic insulating part sleeved on the connecting flap can realize the clamping of the lead wire of the last screen through its own elastic change. Therefore, the present invention will The contact between the lead-out line of the end screen and the signal lead-out device of the end screen of the bushing is surface contact, that is, the peripheral surface contact, which effectively increases the contact area, thereby improving the stability of the connection.

Description

A signal lead-out device for the end screen of a transformer bushing

technical field

The invention relates to the technical field of transformers, in particular to a signal lead-out device for the end screen of a transformer bushing.

Background technique

The transformer is a device that uses the principle of electromagnetic induction to change the AC voltage. It is the main equipment of the power system. It mainly realizes the step-up and step-down in the process of power transmission. The reliability of its operation directly affects the safety and stability of the power system.

Among them, the bushing is an important part of the power transformer. It mainly realizes the connection, insulation and support of the inner outlet of the transformer, and is one of the main factors that cause transformer failures. Due to the severe working conditions of bushings, they are often gradually degraded or damaged due to environmental influences, resulting in grid failures. In order to ensure the normal operation of the power grid, effective preventive tests and on-line monitoring of bushings are required.

In order to evenly distribute the electric field, the high-voltage bushing is composed of multi-layer metal screens and insulating layers between the screens. The last screen is the last screen for equipotential connection with the ground. It must be reliably grounded during operation, so the leakage of the last screen cannot be obtained. Current signal, but in the preventive test, it is necessary to untie the connection with the ground potential in order to detect the capacitance and dielectric loss of the bushing. The bushing insulation on-line monitoring device needs to measure the leakage current from the end screen of the bushing. One end of the current lead-out device is connected to the lead-out line of the end screen of the end screen of the bushing, and the other end is connected to the current measuring device, and then grounded.

However, at present, the connection between the conductive rod of the end screen lead-out device and the end screen lead-out line of the casing end screen is a side contact connection, which makes the contact area small, which is not conducive to the connection between the two, especially when the end screen lead-out device shakes , it is easy to cause unstable connection, and then affect the accuracy of measurement.

Therefore, how to provide a signal lead-out device at the end screen of the transformer bushing to increase the contact area and further improve the stability of the connection is a technical problem to be solved by those skilled in the art.

Contents of the invention

The purpose of the present invention is to provide a signal lead-out device for the end screen of the transformer bushing, so as to increase the contact area and further improve the stability of the connection.

In order to solve the above technical problems, the present invention provides the following technical solutions:

A signal lead-out device for the end screen of a transformer bushing, which is used to lead out the leakage current on the lead-out line of the end screen of the capacitive bushing end screen, including:

An external joint that is sleeved on the interface of the end screen of the capacitive casing through the installation hole;

A protective sleeve connected to the external joint, and a wire hole is opened on the protective sleeve;

A conductive rod connected to the protective sleeve through an elastic insulating member, and at least two petals are arranged on the end of the conductive rod close to the installation hole along the circumferential direction to form a connection with the insertion hole matched with the lead-out wire of the last screen flap, and the elastic insulating member is sleeved on the connecting flap.

Preferably, in the above device, the axis of the conductive rod is parallel to the axis of the protective sleeve, and the end of the conductive rod away from the installation hole is provided with a first threaded hole.

Preferably, the above-mentioned device further includes an inner conversion joint for connecting the protective sleeve and the elastic insulating member.

Preferably, in the above-mentioned device, the outer surface of the inner adapter is threadedly connected with the inner wall of the protective sleeve, and the outer surface of the inner adapter is provided with a second threaded hole.

Preferably, the above-mentioned device further includes protection resistors installed in the first threaded hole and the second threaded hole.

Preferably, the above-mentioned device further includes a connecting nut for connecting the outer joint and the protective sleeve.

Preferably, in the above-mentioned device, the connecting nut is provided with an internal thread, the external joint is provided with an external thread mating with the internal thread, and the connecting nut is provided with a first protrusion, and the protective sleeve A second protrusion is arranged on the top.

Preferably, the above-mentioned device further includes a first limiting spring arranged on the outer surface of the protective sleeve and used to limit the movement of the connecting nut in a direction away from the outer joint; On the conductive rod, it is used to prevent the conductive rod from detaching from the second limit clip spring of the elastic insulating member.

Preferably, the above device further includes a first sealing device for sealing the connection between the outer joint and the end screen interface and a second sealing device for sealing the outer joint and the protective sleeve .

Preferably, the above-mentioned device further includes a waterproof joint arranged at the wire hole.

It can be seen from the above technical solution that the present invention provides a transformer bushing end screen signal lead-out device, which is used to lead out the leakage current on the end screen lead-out line of the capacitive bushing end screen, which includes: through the installation hole sleeve The external joint provided on the interface of the end screen of the capacitive casing; the protective sleeve connected to the external joint, and the protective sleeve is provided with a wire hole; the conductive rod connected to the protective sleeve through an elastic insulating part, the conductive rod The end near the installation hole is arranged with at least two connection petals along the circumference to form the insertion holes for matching with the lead-out wires of the last screen, and the elastic insulating member is sheathed on the connection petals. When testing, install the external connector on the interface of the end screen of the capacitive casing, and at the same time ensure that the lead wire of the end screen is inserted into the insertion hole formed by the connecting flap, that is, the current on the lead wire of the end screen is transferred to the conductive on the pole. The insertion hole is formed by at least two connecting flaps, that is, the size of the insertion hole can change with the insertion depth of the lead-out wire of the end screen, and the elastic insulating part sleeved on the connecting flap can realize the insertion through its own elastic change. The clamping of the lead-out wire of the last screen connected to the insertion hole, therefore, the present invention changes the contact between the lead-out wire of the last screen and the signal lead-out device of the last screen of the casing into surface contact, that is, the peripheral surface contact of the lead-out wire of the last screen, effectively The contact area is increased, which in turn improves the stability of the connection.

Description of drawings

Fig. 1 is a schematic structural diagram of a signal lead-out device for the end screen of a transformer bushing provided by an embodiment of the present invention;

Fig. 2 is a schematic structural view of a conductive rod provided by an embodiment of the present invention;

Fig. 3 is a cross-sectional view of the conductive rod provided by the embodiment of the present invention.

Detailed ways

The core of the invention is to provide a signal lead-out device for the end screen of the transformer bushing to increase the contact area and further improve the stability of the connection.

In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Please refer to Fig. 1-Fig. 3, the present invention discloses a transformer bushing end screen signal lead-out device, which is used to lead out the leakage current on the end screen lead-out line of the capacitive bushing end screen, which includes: through the installation hole The outer joint 1 set on the interface of the end screen of the capacitive casing; the protective sleeve 4 connected with the outer joint 1, and the protective sleeve 4 is provided with a wire hole; it is connected to the protective sleeve 4 through an elastic insulating member 9 The conductive rod 6, the end of the conductive rod 6 close to the installation hole is arranged with at least two connecting petals 61 in the circumferential direction to form the insertion holes that cooperate with the lead-out wires of the end screen, and the elastic insulating member 9 is sleeved on the connecting petals 61 superior.

When testing, install the external joint 1 on the interface of the end screen of the capacitive casing, and at the same time ensure that the lead-out wire of the end screen is inserted into the insertion hole formed by the connecting flap 61, that is, the current transmission on the lead-out line of the end screen is realized to the conductive rod 6. The insertion hole is formed by at least two connecting flaps 61, that is, the size of the insertion hole can change with the insertion depth of the lead wire of the end screen, and the elastic insulating member 9 sleeved on the connecting flap 61 changes through its own elasticity. Realize the clamping of the lead-out wire of the end screen inserted into the insertion hole. Therefore, the present invention changes the contact between the lead-out wire of the end screen and the signal lead-out device of the end screen of the casing into surface contact, that is, the circumference of the lead-out wire of the end screen The surface contact effectively increases the contact area, thereby improving the stability of the connection.

In a specific embodiment, the number and length of the connecting flaps 61 are not limited, and the operator can set them according to different needs. Specifically, the connecting petals 61 may be three or four petals, and the material thereof is copper material with electrical conductivity.

In this embodiment, the axis of the conductive rod 6 and the axis of the protective sleeve 4 are arranged in parallel, and a first threaded hole 62 is provided at the end of the conductive rod 6 away from the installation hole. In order to facilitate the insertion of the lead wires of the last screen into the insertion hole formed by the connecting flap 61, preferably, the axis of the insertion hole is arranged coincident with the axis of the installation hole, that is, the insertion hole is arranged corresponding to the installation hole. In the detection process, the conductive rod 6 is connected to the lead-out wire of the last screen to transfer the current on the lead-out wire of the last screen to the conductive rod, and the external signal cable is passed through the first threaded hole 62 to realize the connection with the conductive rod 6. connected, so as to achieve the purpose of detecting the current on the conductive rod 6.

In a specific embodiment, an inner adapter 11 for connecting the protective sleeve 4 and the elastic insulating member 9 is also included, that is, the connection between the protective sleeve 4 and the elastic insulating member 9 is realized through the inner adapter 11 during installation. In actual setting, the inner adapter 11 is set as a hollow structure, and the elastic insulating member 9 is clamped at the hollow position of the inner adapter 11 to realize the connection to the elastic insulating member 9 . Preferably, the outer ring of the elastic insulating member 9 is screwed to the inner ring of the inner adapter 11 , and the inner ring of the elastic insulating member 9 is screwed to the outer ring of the conductive rod 6 .

Preferably, the outer surface of the inner adapter 11 is threadedly connected with the inner wall of the protective sleeve 4 , and the outer surface of the inner adapter 11 is provided with a second threaded hole (not shown in the figure). Those skilled in the art can understand that the connection between the inner adapter 11 and the protective sleeve 4 can also be realized through other connection methods, and all of them are within the scope of protection.

In a further embodiment, the signal extraction device at the end screen of the transformer bushing further includes a protective resistor 7 installed between the first threaded hole 62 and the second threaded hole. One end of the protection resistor 7 is installed in the first threaded hole 62 , and the other end is installed in the second threaded hole. By setting the protection resistor 7, it can be ensured that when the external signal cable is accidentally disconnected, the end screen of the bushing can still be grounded through the protection resistor 7, preventing the end screen of the bushing from being opened and ensuring safe operation of the bushing.

This embodiment also provides a connection method between the protective sleeve 4 and the outer joint 1 , specifically, the connection between the outer joint 1 and the protective sleeve 4 is realized through the connection nut 2 . Those skilled in the art can understand that in actual production, connections can be made according to different connection modes, and all of them are within the protection scope of this embodiment.

Specifically, an internal thread is provided on the connecting nut 2, and an external thread cooperating with the internal thread is provided on the external joint 1 accordingly, that is, the connection between the connecting nut 2 and the external joint 1 is realized through thread fit. A first protrusion is provided on the side of the connecting nut 2 away from the outer joint 1 , and the inner diameter of the first protrusion is larger than the outer diameter of the protective sleeve 4 , and a second protrusion is provided on the outer side of the protective sleeve 4 accordingly. When installing, the connecting nut 2 is connected with the outer joint 1 through threads, and forms a first groove with the first protrusion, and the second protrusion on the protective sleeve 4 is just stuck in the above groove, so that 2 Connect the outer joint 1 and the protective sleeve 4.

In addition, a second groove is provided on the outer joint 1 , and a third protrusion is correspondingly provided on the inner transfer joint 11 . During installation, the third protrusion of the inner transfer joint 11 can extend into the second groove of the outer joint 1, thereby realizing a position-limited connection. Through the above arrangement, the sealing performance of the device is effectively guaranteed, and the connection method is convenient for disassembly and assembly, which greatly reduces the labor intensity of the operator.

In the actual operation process, in order to prevent the connection nut 2 from falling off from the outer joint 1 after the threaded connection between the connection nut 2 and the outer joint 1 is loosened, a protective sleeve 4 is provided on the protective sleeve 4 in this embodiment to limit the connection nut. 2 The first limit snap spring 3 that moves away from the outer joint 1. When the connecting nut 2 is loose, it will be displaced relative to the outer joint 1, and when it moves to the position of the first limit jumper 3, the connecting nut 2 cannot continue to run, thereby preventing it from falling off from the outer joint 1.

In addition, in order to prevent the conductive rod 6 from detaching from the elastic insulator 9 , this embodiment also provides a second limiting clip 8 , specifically, the second clip 8 is arranged at the end of the conductive rod 6 away from the installation hole. Since the inner ring of the elastic insulator 9 is connected to the conductive rod 6, and the outer ring is connected to the inner adapter 11, therefore, when the lead-out wire of the last screen is pulled out from the connecting flap 61, if the conductive rod 6 is connected to the elastic insulator 9 When it is tighter, it will cause the conductive rod 6 to break away from the elastic insulating member 9 along with the lead-out line of the last screen. In the present application, the second clamp spring 8 can prevent the relative displacement between the elastic insulating member 9 and the conductive rod 6, thereby preventing the conductive rod 6 from detaching from the device.

On the basis of the above-mentioned technical solution, in order to ensure the overall sealing of the signal lead-out device of the transformer bushing end screen and to prevent leakage, this embodiment also includes a first connection between the outer joint 1 and the end screen interface. A sealing device 12 and a second sealing device 10 arranged between the outer joint 1 and the protective sleeve 4 . Specifically, when the outer joint 1 is connected to the interface of the capacitive casing end screen, the first sealing device 12 ensures the sealing between the two; when the outer joint 1 and the protective sleeve 4 are tightened, the second sealing device 10 Ensure the tightness between the two. Preferably, the first sealing device 12 and the second sealing device 10 can both be sealing gaskets, but this embodiment does not limit their specific forms.

In a further embodiment, in order to ensure the safety of the external signal cable drawn out from the wire hole, a waterproof joint 5 is provided at the wire hole. The sealing of the wire hole is realized by the waterproof joint 5 . The outer casing of the waterproof joint 5 is made of metal to ensure the strength and hardness of the waterproof joint 5 ; and the interior is made of plastic to ensure the insulation and sealing of the waterproof joint 5 . In this embodiment, the materials are not limited to the above materials, and can be selected according to different needs during actual operation.

Before the on-site installation, the components inside the protective sleeve 4 are firstly installed, and the signal cable is led out through the waterproof connector 5 at the end of the protective sleeve 4 . When installing, first unscrew the grounding cap at the interface of the end screen of the bushing, and fix the outer joint 1 to the original position of the grounding cap through threads. Then align the overall structure of the previously installed protective sleeve with the outer joint 1, so that the lead wire at the end of the sleeve is just inserted into the insertion hole of the conductive rod 6, and rotate the overall structure of the protective sleeve until it cannot be rotated. The third protrusion at the front end of the joint 11 just snaps into the second groove of the outer joint 1 . Finally, the connecting nut 2 is aligned with the external thread on the external joint 1 and tightened to realize the connection between the casing end screen and the external joint 1 .

When conducting bushing power failure test, it is necessary to remove the signal lead-out device. Unscrew the connecting nut 2 at this time, and then pull off the overall structure of the protective sleeve, and the outer joint 1 does not need to be removed. This disassembly method removes the protective resistor 7 and the terminal signal cable together, which can prevent the signal cable from being twisted and lead to an open circuit during removal, and can also avoid the hidden danger of forgetting to install the protective resistor 7 after being removed.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. a Transformer Bushing Tap signal ejector, the Leakage Current on the end shield lead-out wire of drawing condenser bushing end shield, is characterized in that, comprising:

The coupling (1) on the interface of described condenser bushing end shield is set in by installing hole;

The protective sleeve (4) be connected with described coupling (1), (4) offer wire guide to described protective sleeve;

By the conducting rod (6) that elastic insulation pieces (9) is connected with described protective sleeve (4), one end of the close described installing hole of described conducting rod (6) circumferentially has at least two lobes to form the connection lobe (61) of the plug-in opening coordinated with described end shield lead-out wire, and described elastic insulation pieces (9) is set on described connection lobe (61).

2. device according to claim 1, is characterized in that, the axis of described conducting rod (6) and the axis being parallel of described protective sleeve (4), and one end away from described installing hole of described conducting rod (6) offers the first screwed hole (62).

3. device according to claim 2, is characterized in that, also comprises the interior adapter (11) for connecting described protective sleeve (4) and described elastic insulation pieces (9).

4. device according to claim 3, is characterized in that, the outer surface of described interior adapter (11) is connected by screw thread with the inwall of described protective sleeve (4), and the outer surface of described interior adapter (11) offers the second screwed hole.

5. device according to claim 4, is characterized in that, also comprises the protective resistance (7) be arranged in described first screwed hole (62) and the second screwed hole.

6. device according to claim 1, is characterized in that, also comprises the attaching nut (2) for connecting described coupling (1) and described protective sleeve (4).

7. device according to claim 6, it is characterized in that, described attaching nut (2) is provided with internal thread, described coupling (1) is provided with the external screw thread with described screw-internal thread fit, and described attaching nut (2) is provided with the first projection, described protective sleeve (4) is provided with the second projection.

8. device according to claim 6, is characterized in that, also comprises the outer surface being arranged on described protective sleeve (4), and for limiting the first spacing jump ring (3) that described attaching nut (2) moves to the direction away from described coupling (1); Be arranged on described conducting rod (6), for the second spacing jump ring (8) preventing described conducting rod (6) from departing from described elastic insulation pieces (9).

9. the device according to any one of claim 1-8, it is characterized in that, also comprising for sealing described coupling (1) and first sealing device (12) of the junction of described end shield interface and the second sealing device (10) for sealing described coupling (1) and described protective sleeve (4).

10. device according to claim 9, is characterized in that, also comprises the water joint (5) being arranged on described wire guide place.