CN214753330U

CN214753330U - External plug-in type casing

Info

Publication number: CN214753330U
Application number: CN202023026374.0U
Authority: CN
Inventors: 王学东
Original assignee: Anhui Jinrui Electric Co ltd
Current assignee: Anhui Jinrui Electric Co ltd
Priority date: 2020-12-15
Filing date: 2020-12-15
Publication date: 2021-11-16
Anticipated expiration: 2030-12-15

Abstract

An externally-inserted bushing comprises a first bushing and a second bushing, wherein the first bushing is used for being connected with a transformer, the second bushing is connected with the first bushing in an inserting and pulling mode, the first bushing comprises a first guide rod and a first insulating core body wrapped outside the first guide rod, one end of the first guide rod and one end of the first insulating core body are used for being inserted into the transformer and electrically connected with the transformer, the second bushing comprises a second guide rod and a second insulating core body wrapped outside the second guide rod, one end of the first guide rod and one end of the first insulating core body are inserted into the second insulating core body and connected with the second insulating core body, and one end of the first guide rod is electrically connected with one end of the second guide rod, the first sleeve can be firstly arranged on the transformer when in use, the second sleeve is connected with the first sleeve in a plugging way, the transformer can be subjected to various factory tests, the first sleeve does not need to be detached and the transformer does not need to be subjected to oil unloading treatment when the transformer leaves a factory, and the second sleeve is inserted into the first sleeve after the transformer leaves the installation site.

Description

External plug-in type casing

Technical Field

The invention relates to the field of low-voltage apparatuses, in particular to an external plug-in sleeve.

Background

The transformer bushing is a high-voltage device widely used in a power system, is fixedly arranged on a shell of a transformer and is used for connecting external electric conductors such as cables or buses and the like with the transformer, one end of the transformer bushing extends into the shell of the transformer and is electrically connected with a coil lead of the transformer, and the other end of the transformer bushing extends out of the shell of the transformer and is electrically connected with the cables or buses exposed outside the transformer.

The direct type transformer bushing can be directly installed on a shell of the transformer, but the direct type transformer bushing is required to unload oil to the transformer before being detached, is inconvenient to assemble and disassemble and is troublesome in installation, maintenance and factory test, and the indirect type transformer bushing is required to add an intermediate bushing between the transformer bushing and the transformer, so that the direct type transformer bushing is convenient to install, maintain and test, but is large in size, high in precision requirement and cost and difficult to meet the use requirement. Furthermore, since the plug portion of the intermediate bushing in air and the counterpart of the transformer present the problem of adverse effects of strong electric fields during operation of the bushing, in order to control this electric field effectively, it is necessary to use an elastically deformable insulator on the tapered insulator section of the bushing, an insulating sleeve which can seal the insulating medium on the plug portion of the transformer bushing and which is provided with an inner surface which is substantially identical to the contour of the tapered insulator section, the insulator being pressed against the inner surface of the insulating sleeve and being elastically deformed when the plug contact of the plug portion of the bushing and the plug contact of the plug portion of the transformer bushing engage one another. However, since there is inevitably a gap between the insulator and the insulating sleeve, and the gap is inevitably communicated with the two plug contacts, especially the gap is unstable due to manufacturing errors such as processing and assembling and changes of ambient temperature, under the action of a strong electric field of the plug contacts, unevenness of electric field distribution and potential difference may occur between points in the gap, which easily causes flashover and heat generation.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an external plug-in sleeve with simple structure and high reliability.

In order to achieve the purpose, the invention adopts the following technical scheme:

the first sleeve comprises a first guide rod and a first insulating core body wrapped outside the first guide rod, one end of the first guide rod and one end of the first insulating core body are used for being inserted into the transformer and electrically connected with the transformer, the second sleeve comprises a second guide rod and a second insulating core body wrapped outside the second guide rod, one end of the first guide rod and one end of the first insulating core body are inserted into the second insulating core body and connected with the second guide rod, and one end of the first guide rod and one end of the second insulating core body are electrically connected with one end of the second guide rod.

Preferably, the length of the first insulating core body is gradually reduced from inside to outside, tapered portions are respectively formed on the outer sides of the two ends of the first insulating core body, the tapered portion at one end is inserted into the second insulating core body, and an elastic insulating core body is arranged between the tapered portion and the second insulating core body.

Preferably, one end of the elastic insulating core body is provided with a limiting ring, and the other end of the elastic insulating core body is provided with a pressing mechanism; the second insulation core is internally provided with a guide rod hole for accommodating the second guide rod, the first guide rod extends out of the first insulation core and is inserted into the guide rod hole, the limiting ring is arranged between the periphery of the first guide rod and the inner wall of the guide rod hole, and the pressing mechanism is arranged on the periphery of the first insulation core.

Preferably, a plurality of first capacitive screens alternately arranged with the insulating layers are arranged in the first insulating core body, the diameters of the plurality of first capacitive screens are gradually increased from the inner side to the outer side, and the lengths of the plurality of first capacitive screens are gradually contracted from the inner side to the outer side; the first insulation core body is provided with a plurality of voltage division capacitive screens which are alternately arranged with the insulation layer correspondingly on the outer side of the first capacitive screen, the voltage division capacitive screens are connected in parallel to form a first voltage division capacitor, and the first voltage division capacitor and a first main capacitor formed by connecting the first capacitive screens in series form a capacitive voltage divider.

Preferably, an air core coil or an iron core coil is sleeved outside the first insulating core.

Preferably, the second insulating core comprises a plurality of second capacitive screens alternating with insulating layers.

Preferably, the diameters of the plurality of second capacitive screens gradually increase from the inside to the outside, and the lengths of the plurality of second capacitive screens gradually shrink from the inside to the outside and gradually deviate towards one side of the first sleeve.

Preferably, a connecting flange is arranged on the outer side of the first sleeve, a flange base is arranged on the transformer, a second flange is arranged at one end of the second sleeve connected with the first sleeve, one end of the first sleeve is used for being inserted into the transformer and is fixed with the flange base through the connecting flange, the second sleeve is fixed with the second flange through the connecting flange after being connected with the first sleeve in a plug-in mode, a measuring terminal is arranged on one side of the connecting flange, a silicon rubber umbrella skirt is arranged on the outer side of the plug-in sleeve, a sealing end cover is arranged at the other end of the second sleeve connected with the first sleeve, and the second guide rod penetrates through the sealing end cover to stretch out the second sleeve to be connected with the wiring terminal.

Preferably, the middle part of the first sleeve corresponding to the connecting flange is provided with an insulating bulge for accommodating a voltage-dividing capacitive screen, one end of the insulating bulge is provided with a pressing mechanism matched with the elastic insulating core, and the other end of the insulating bulge is provided with an air-core coil or an iron-core coil sleeved outside the first insulating core; the connecting flange wraps the insulating protrusion and the hollow coil or the iron core coil, and after the insulating protrusion and the hollow coil or the iron core coil are installed, the first sleeve is completely wrapped by the second sleeve, the connecting flange and the transformer.

Preferably, the end of the second insulating core is provided with an extension protrusion connected with the edge of the insulating protrusion, a space for accommodating the pressing mechanism is enclosed among the extension protrusion, the insulating protrusion and the first insulating core, and a pressing plate is arranged between the pressing mechanism and the elastic insulating core.

The invention provides an external plug-in sleeve, which comprises a first sleeve connected with a transformer and a second sleeve connected with the first sleeve in a plug-in manner. Further, by compressing the elastic insulating core between the first insulating core and the second insulating core, a strong electric field generated during operation can be effectively controlled.

Drawings

FIG. 1 is a schematic structural diagram of an external plug-in bushing according to the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 of the present invention;

Detailed Description

The following description will further describe the embodiment of the external plug-in type cannula according to the present invention with reference to the embodiments shown in fig. 1 to 2. The inventive external plug-in bushing is not limited to the description of the following embodiments.

As shown in fig. 1, the external plug-in bushing of the present invention includes a first bushing for connecting with a transformer 3 and a second bushing for plug-in connecting with the first bushing, the first bushing includes a first guide rod 1 and a first insulating core 10 wrapped outside the first guide rod 1, one end of the first guide rod 1 and one end of the first insulating core 10 are used for being inserted into the transformer 3 and electrically connected with the transformer 3, the second bushing includes a second guide rod 2 and a second insulating core 20 wrapped outside the second guide rod 2, one end of the first guide rod 1 and one end of the first insulating core 10 are inserted into the second insulating core 20 and connected, and one end of the first guide rod 1 is electrically connected with one end of the second guide rod 2. The pluggable transformer 3 sleeve comprises a first sleeve connected with the transformer 3 and a second sleeve connected with the first sleeve in a pluggable mode, the first sleeve can be installed on the transformer 3 in use, the second sleeve is connected with the first sleeve in a pluggable mode, so that the transformer 3 can be subjected to various delivery tests, the first sleeve does not need to be detached when the transformer is delivered from a factory, the transformer 3 does not need to be subjected to oil unloading treatment, and the second sleeve is plugged on the first sleeve after the transformer is delivered to an installation site.

One end of the first sleeve connected with the transformer 3 or the GIS combined electrical apparatus is matched with an interface of the transformer 3, and the first sleeve accords with corresponding standards. One end of the first sleeve connected with the second sleeve is connected in a plug-in mode, and the second sleeve is sleeved on the first sleeve. The second sleeve can be a transformer 3 sleeve, and is combined with the first sleeve to form a plug-in type transformer 3 sleeve; in addition, the second bushing may be a cable terminal, which is combined with the first bushing to form a plug-in cable terminal connected to the transformer 3; so that the user can replace the second cannula as the case may be. The second sleeve is of course of other forms but it must necessarily be a plug-in connection with the first sleeve.

In the preferred embodiment of the invention, as shown in fig. 1, the external plug-in type bushing includes a first bushing for connecting with the transformer 3 and a second bushing for connecting with the first bushing, and the first bushing and the second bushing are connected to form a transformer bushing. The first bushing comprises a first guide rod 1 and a first insulating core 10 wrapped outside the first guide rod 1, one ends of the first guide rod 1 and the first insulating core 10 are used for being inserted into a transformer 3 and electrically connected with the transformer 3, the second bushing comprises a second guide rod 2 and a second insulating core 20 wrapped outside the second guide rod 2, one ends of the first guide rod 1 and the first insulating core 10 are inserted into the second insulating core 20 and connected, one end of the first guide rod 1 is electrically connected with one end of the second guide rod 2, and the other end of the second guide rod 2 is connected with a wiring terminal 4 at the end of the second insulating core 20.

Further, the length of the first insulating core 10 is gradually reduced from inside to outside, tapered portions 11 are respectively formed on the outer sides of both ends of the first insulating core 10, the tapered portion 11 at one end is inserted into the second insulating core 20, and an elastic insulating core 21 is arranged between the tapered portion 11 and the second insulating core 20. Preferably, a stopper ring 23 is provided at one end of the elastic insulating core 21 and a pressing mechanism 22 is provided at the other end, and by pressing the elastic insulating core 21 between the first insulating core 10 and the second insulating core 20, a strong electric field generated during operation can be effectively controlled.

Preferably, the end of the first guide rod 1 is provided with a slot 18, the end of the second guide rod 2 is provided with a plug 19 inserted into the slot 18, and the inner wall of the slot 18 is provided with a flow guide contact matched with the plug 19.

Further, be equipped with the guide rod hole 24 that holds second guide arm 2 in the second insulating core 20, the one end that first guide arm 1 is connected with second guide arm 2 stretches out first insulating core 10 and inserts guide rod hole 24, spacing ring 23 sets up around first guide arm 1 and between the inner wall of guide rod hole 24, hold-down mechanism 22 sets up around first insulating core 10, through setting up spacing ring 23 around first guide arm 1 and between the inner wall of guide rod hole 24, not only can cooperate and compress tightly elastic insulation core 21, but also can avoid elastic insulation core 21 clearance all around and first guide arm 1 and the contact of second guide arm 2, avoid appearing the inhomogeneous and potential difference of electric field distribution, lead to flashover and the scheduling problem that generates heat. Of course, the positions of the pressing mechanism 22 and the limiting ring 23, or the positions of the slot 18 and the plug 19, are reversed, which also falls within the protection scope of the present invention.

Further, a plurality of first capacitive screens 101 which are alternately arranged with the insulating layers are arranged in the first insulating core 10, the diameters of the plurality of first capacitive screens 101 are gradually increased from the inner side to the outer side, and the lengths of the plurality of first capacitive screens 101 are gradually contracted from the inner side to the outer side to form a step-shaped retraction; the first insulation core body 10 is provided with a plurality of voltage division capacitance screens 13 which are alternately arranged with the insulation layer corresponding to the outer side of the first capacitance screen 101, the voltage division capacitance screens 13 are connected in parallel to form a first voltage division capacitor, the first voltage division capacitor and a first main capacitor formed by connecting the first voltage division capacitor and the first capacitance screens 101 in series form a capacitance voltage divider, and a voltage measuring device and/or an insulation monitor and/or a partial discharge detector can be connected to the leading-out wire between the first main capacitor and the first voltage division capacitor to monitor the voltage, the waveform and the partial discharge of the substation. In addition, a tap may be connected from the 2 nd from the outer side of the first main capacitor to the first main capacitor screen 101 without separately winding the first voltage dividing capacitor, thereby forming a capacitor voltage divider.

Further, an air core coil 14 or an iron core coil is sleeved outside the first insulating core 10, so that the change of the current in the first insulating core 10 can be induced, and the function of the electronic current transformer is realized.

Still further, a plurality of second capacitive screens 201 which are alternately arranged with the insulating layers are arranged in the second insulating core 20; the diameters of the second capacitive screens 201 gradually increase from the inside to the outside, and the lengths gradually shrink from the inside to the outside and gradually shift to the first sleeve. Preferably, a silicon rubber umbrella skirt 31 is arranged on the outer side of the plug sleeve 30, a sealing end cover 32 is arranged at the other end, connected with the first sleeve, of the second sleeve, and the second guide rod 2 penetrates through the sealing end cover 32 and extends out of the second sleeve to be connected with the connecting terminal 4.

Specifically, as shown in fig. 1, a connecting flange 15 is arranged on the outer side of the first sleeve, a flange base 17 is arranged on the transformer 3, a second flange is arranged at one end of the second sleeve connected with the first sleeve, one end of the first sleeve is inserted into the transformer 3 or the GIS combined electrical apparatus to be electrically connected with the transformer 3, the first sleeve is fixedly connected with the flange base 17 through the connecting flange 15 and is subjected to sealing treatment, and the second sleeve is fixedly connected with the second flange through the connecting flange 15 and is subjected to sealing treatment after being connected with the first sleeve in a plug-pull manner. Preferably, sealing rings 33 are respectively arranged between the connecting flange 15 and the second flange, between the connecting flange 15 and the flange base 17, and between the flange base 17 and the first insulating core 10 of the first sleeve. A measuring terminal 16 is arranged on one side of the connecting flange 15, the first voltage-dividing capacitor and the first main capacitor form outgoing lines of a capacitive voltage divider, and the outgoing lines of the hollow coil 14 can be connected with measuring equipment through the measuring terminal 16.

Preferably, the air coil 14 or the core coil is disposed between the connection flange 15 and the first insulating core 10 of the first bushing; the connecting flange 15 wraps the exposed part of the first sleeve, namely, after the first sleeve is installed, the second sleeve, the connecting flange 15 and the transformer completely wrap the first sleeve; the second sleeve, the connecting flange 15 and the transformer respectively wrap all parts of the first sleeve, and the silicon rubber umbrella skirt 31 is arranged outside the second sleeve. Furthermore, the middle part of the first sleeve corresponding to the connecting flange 15 is provided with an insulating bulge 12 for accommodating a voltage-dividing capacitive screen 13, and the diameter of the insulating bulge is larger than that of other parts; one end of the insulating bulge 12 is provided with a pressing mechanism 22 matched with the elastic insulating core body 21, and the other end is provided with an air core coil 14 or an iron core coil sleeved outside the first insulating core body 10. The insulating bulge 12 is accommodated with the voltage-dividing capacitive screen 13, and meanwhile, two ends of the insulating bulge are respectively matched with the pressing mechanism 22 and the hollow coil 14, and the insulating bulge further has the characteristics of compact structure and small size.

Furthermore, the end of the second insulating core 20 is provided with an extension protrusion 25 connected with the edge of the insulating protrusion 12, a space for accommodating the pressing mechanism 22 is enclosed among the extension protrusion 25, the insulating protrusion 12 and the first insulating core 10, and a pressing plate 26 is arranged between the pressing mechanism 22 and the elastic insulating core 21, so that the sealing performance of the transformer bushing is better.

The foregoing is a more detailed description of the invention in connection with specific, preferred embodiments, and it is not intended to limit the invention to the particular forms disclosed. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the inventive concept, and all should be considered as falling within the protection scope of the invention.

Claims

1. An external plug-in cannula, characterized in that: the transformer comprises a first sleeve and a second sleeve, wherein the first sleeve is used for being connected with a transformer (3) and the second sleeve is connected with the first sleeve in a plugging mode, the first sleeve comprises a first guide rod (1) and a first insulation core body (10) wrapped outside the first guide rod (1), one ends of the first guide rod (1) and the first insulation core body (10) are used for being inserted into the transformer (3) and electrically connected with the transformer (3), the second sleeve comprises a second guide rod (2) and a second insulation core body (20) wrapped outside the second guide rod (2), one ends of the first guide rod (1) and the first insulation core body (10) are inserted into the second insulation core body (20) for connection, and one end of the first guide rod (1) is electrically connected with one end of the second guide rod (2).

2. The external plug-in cannula according to claim 1, wherein: the length of the first insulating core body (10) is gradually reduced from inside to outside, the outer sides of two ends of the first insulating core body (10) are respectively provided with a tapered part (11), the tapered part (11) at one end is inserted into the second insulating core body (20), and an elastic insulating core body (21) is arranged between the tapered part (11) and the second insulating core body (20).

3. The external plug-in cannula according to claim 2, wherein: one end of the elastic insulating core body (21) is provided with a limiting ring (23), and the other end is provided with a pressing mechanism (22); be equipped with guide rod hole (24) that hold second guide arm (2) in second insulating core (20), first guide arm (1) stretches out first insulating core (10) and inserts guide rod hole (24), and spacing ring (23) set up around first guide arm (1) and between the inner wall of guide rod hole (24), and hold-down mechanism (22) set up around first insulating core (10).

4. The external plug-in cannula according to claim 1, wherein: a plurality of first capacitive screens (101) which are alternately arranged with the insulating layers are arranged in the first insulating core body (10), the diameters of the first capacitive screens (101) are gradually increased from the inner side to the outer side, and the lengths of the first capacitive screens are gradually contracted from the inner side to the outer side; the first insulation core body (10) is provided with a plurality of voltage division capacitance screens (13) which are alternately arranged with the insulation layer corresponding to the outer side of the first capacitance screen (101), the voltage division capacitance screens (13) are connected in parallel to form a first voltage division capacitor, and the first voltage division capacitor and a first main capacitor formed by connecting the first voltage division capacitor and the first capacitance screens (101) in series form a capacitance voltage divider.

5. An external plug-in bushing according to claim 1 or 4, characterized in that: an air core coil (14) or an iron core coil is sleeved outside the first insulating core body (10).

6. The external plug-in cannula according to claim 1, wherein: the second insulating core (20) comprises a plurality of second capacitive screens (201) alternating with insulating layers.

7. The external plug-in cannula according to claim 6, wherein: the diameters of the second capacitive screens (201) are gradually increased from the inner side to the outer side, and the lengths of the second capacitive screens are gradually contracted from the inner side to the outer side and gradually offset to one side of the first sleeve.

8. The external plug-in cannula according to claim 1, wherein: the transformer is characterized in that a connecting flange (15) is arranged on the outer side of the first sleeve, a flange base (17) is arranged on the transformer (3), a second flange is arranged at one end of the second sleeve connected with the first sleeve, one end of the first sleeve is used for inserting the transformer (3) and is fixed with the flange base (17) through the connecting flange (15), the second sleeve is fixed with the second flange through the connecting flange (15) after being connected with the first sleeve in a plug-in mode, a measuring terminal (16) is arranged on one side of the connecting flange (15), a silicon rubber umbrella skirt (31) is arranged on the outer side of the plug-in sleeve (30), a sealing end cover (32) is arranged at the other end of the second sleeve connected with the first sleeve, and the second guide rod (2) penetrates through the sealing end cover (32) to stretch out the second sleeve to be connected with a connecting terminal (4).

9. The external plug-in cannula according to claim 8, wherein: the middle part of the first sleeve corresponding to the connecting flange (15) is provided with an insulating bulge (12) for accommodating a voltage-dividing capacitive screen (13), one end of the insulating bulge (12) is provided with a pressing mechanism (22) matched with the elastic insulating core body (21), and the other end of the insulating bulge is provided with an air core coil (14) or an iron core coil sleeved outside the first insulating core body (10); the connecting flange (15) wraps the insulating protrusion (12) and the hollow coil (14) or the iron core coil, and after the mounting, the first sleeve is completely wrapped by the second sleeve, the connecting flange (15) and the transformer.

10. The external plug-in cannula according to claim 9, wherein: the end part of the second insulating core body (20) is provided with an extension bulge (25) connected with the edge of the insulating bulge (12), a space for accommodating the pressing mechanism (22) is enclosed among the extension bulge (25), the insulating bulge (12) and the first insulating core body (10), and a pressing plate (26) is arranged between the pressing mechanism (22) and the elastic insulating core body (21).