Test tap structure of high-voltage capacitive bushing

Abstract

The invention belongs to the field of high-voltage capacitive bushings, and particularly relates to a test tap structure of a high-voltage capacitive bushing. The structure comprises a binding post, an insulator, a mounting flange, a connecting ring, a grounding sleeve, an elastic conductive piece, a gland, a safety ring, a protective cover, an insulating ejector pin and a supporting insulating pin. According to the test tap structure of the high-voltage capacitive bushing, when the protective cover is opened, the bushing is still in a grounding state, and after the safety ring is detached, the bushing can be in a non-grounding state for measurement by means of the insulating ejector pin and the supporting insulating pin; the problems that the sleeve is suspended under the condition that the protective cover is not screwed tightly after measurement, and the sleeve is continuously suspended and discharged during high-voltage operation, so that great potential safety hazards are brought to safe operation of the sleeve are solved.

Description

Technical Field

[0001] The invention relates to a high-voltage capacitor bushing used in the power transmission and transformation industry, and in particular to a test tap structure of the high-voltage capacitor bushing. Background Art

[0002] The test tap of the high voltage capacitive bushing is a structure that is easily wired from the outside of the bushing, insulated from the flange or other fastening devices and connected to the outermost plate of the capacitive bushing, so as to measure the dielectric loss factor tanδ, capacitance and partial discharge.

[0003] The test tap structure of the existing high-voltage capacitor bushing is as follows: Figure 1 As shown, it includes a terminal 9, an insulator 8 sleeved on the terminal 9, a mounting flange 15 sleeved on the insulator 8, and a protective cover 1 mounted on the insulator 8. The terminal 9 is connected to the capacitor core 14 of the high-voltage capacitor bushing through a lead 10. When the protective cover 1 is opened, the high-voltage capacitor bushing is in a non-grounded state and can be directly measured.

[0004] However, if the protective cover 1 is not tightened after measurement, the structure may easily cause the bushing to be suspended in the air, and the bushing may continue to discharge in suspension during high-voltage operation, which may bring great potential safety hazards to the safe operation of the bushing. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problem that when the protective cover of the existing test tap structure is not tightened after measurement, the bushing is easily suspended and the bushing continues to be suspended and discharged during high-voltage operation, which brings great safety hazards to the safe operation of the bushing, and to provide a test tap structure for a high-voltage capacitive bushing.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A test tap structure of a high voltage capacitive bushing has the following characteristics:

[0008] It includes a terminal post, an insulator, a mounting flange, a connecting ring, a grounding sleeve, an elastic conductive part, a gland, a safety ring, a protective cover, an insulating ejector pin and a supporting insulating pin;

[0009] The lower end of the terminal is used to connect to the capacitor core of the high-voltage capacitor bushing through a lead wire;

[0010] The insulator is sleeved on the terminal post, and its upper end is shorter than the upper end of the terminal post, and its lower end is not shorter than the lower end of the terminal post;

[0011] An annular boss is provided on the outer wall of the insulator, and the mounting flange is sleeved on the annular boss on the outer wall of the insulator and is grounded;

[0012] The connecting ring and the grounding sleeve are respectively sleeved on the terminal post, and a gap is provided between the two along the axial direction. The grounding sleeve can move along the axial direction of the terminal post. The connecting ring is fixedly sleeved on the terminal post, and its lower end abuts against the upper end of the insulator.

[0013] The elastic conductive member is sleeved on the terminal post and located at the interval, and its two ends are respectively connected to the connecting ring and the grounding sleeve;

[0014] The gland is sleeved on the insulator, and its lower end is in contact with the annular boss and the mounting flange respectively, and is fixedly connected to the mounting flange through a connecting piece;

[0015] An annular step is provided at the lower end of the outer circumference of the grounding sleeve, and the upper surface of the annular step of the grounding sleeve abuts against the inner wall of the upper end of the gland in the initial state. A safety gap is provided between the outer circumference of the grounding sleeve and the inner hole of the upper end of the gland. The safety ring sleeve is mounted on the grounding sleeve and contacts the outer wall of the upper end of the gland;

[0016] The protective cover is sleeved on the upper end of the gland;

[0017] A mounting through hole is provided on the peripheral side of the upper end of the terminal. During the test, the insulating ejector pin abuts against the upper end of the grounding sleeve, and is used to drive the grounding sleeve axially close to the connecting ring under the action of external force until the mounting through hole is completely exposed. During the test, the supporting insulating pin is installed in the mounting through hole, and is used to axially position the grounding sleeve; during the test, the upper end of the terminal is used to connect the test line to realize the test measurement.

[0018] Furthermore, a threaded section is provided at the upper end of the outer circumferential surface of the grounding sleeve, an axial interval is provided between the threaded section and the annular step, and the outer diameter of the grounding sleeve at the threaded section is smaller than the outer diameter at the axial interval, and a grounding sleeve step is formed between the two; the interval between the outer circumferential surface of the grounding sleeve at the axial interval and the inner hole at the upper end of the gland is the safety interval;

[0019] The safety ring is a safety nut, which is sleeved on the threaded section of the grounding sleeve;

[0020] The insulating ejector pin is a cylindrical structure with openings at both ends, and an annular groove is provided on the inner wall of the lower end thereof. Two arc-shaped notches are provided on the circumferential side of the insulating ejector pin located at the annular groove, and the two arc-shaped notches are symmetrically arranged along the circumferential direction and are provided with a gap; the two arc-shaped notches are respectively connected to the annular groove and extend axially to the lower end of the insulating ejector pin;

[0021] The axial dimension of the inner wall of the insulating ejector pin at the annular groove is matched with the axial dimension of the threaded section of the grounding sleeve, and the outer diameter of the insulating ejector pin at the annular groove is matched with the inner hole diameter of the upper end of the gland;

[0022] During the test, the lower end of the insulating ejector pin abuts against the step of the grounding sleeve, and the bottom of the annular groove abuts against the upper end of the grounding sleeve.

[0023] Furthermore, in an initial state, the lower end of the threaded section is flush with the upper outer wall of the gland.

[0024] Furthermore, a mounting ring groove is provided on the upper end of the outer peripheral surface of the gland, and the upper end of the mounting ring groove extends axially to the upper end surface of the gland;

[0025] The outer peripheral surface of the gland located at the mounting ring groove is provided with an external thread;

[0026] The inner circumferential surface of the protective cover is provided with an internal thread section matched with the external thread on the gland, and the internal thread section of the protective cover is connected to the external thread of the gland.

[0027] Furthermore, an annular protrusion is provided at the lower end of the outer peripheral surface of the gland, and an axial distance is provided between the lower surface of the annular protrusion and the lower end surface of the gland;

[0028] The lower end surface of the gland is in plane contact with the upper surface of the annular step of the insulator, the lower surface of the annular protrusion is in plane contact with the upper surface of the mounting flange, and the annular protrusion is fixedly connected to the mounting flange by bolts.

[0029] Furthermore, the grounding sleeve and the connecting ring are connected via a grounding wire.

[0030] Furthermore, the elastic conductive member is a spring, and the connecting ring is a connecting nut.

[0031] Furthermore, during testing, the upper end of the terminal can be connected to a test line via a wire clip.

[0032] The beneficial effects of the present invention are:

[0033] 1. The test tap structure of the high-voltage capacitor bushing of the present invention is that when the protective cover is opened, the bushing is still in a grounded state. After the safety ring is removed, the bushing must be placed in a non-grounded state for measurement by using an insulating ejector pin and a supporting insulating pin. This avoids the problem that the bushing is suspended in the air and the bushing continues to be suspended and discharged during high-voltage operation when the protective cover is not tightened after measurement, which brings great safety hazards to the safe operation of the bushing.

[0034] 2. The grounding wire in the present invention is a double grounding insurance. When the spring does not work under special circumstances, the grounding wire can still ensure the safe grounding of the casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the test tap structure of the existing high-voltage capacitive bushing;

[0036] Figure 2is a schematic diagram of the structure of an embodiment of the present invention in a grounded state;

[0037] Figure 3 It is a schematic diagram of the installation of the insulating ejector pin and the supporting insulating pin in the test state of the embodiment of the present invention;

[0038] Figure 4 It is a schematic diagram of the connection between the terminal, the wire clamp and the test wire in the test state of the embodiment of the present invention;

[0039] Figure 5 Schematic diagram of the structure of the insulating ejector pin in the embodiment of the present invention.

[0040] In the figure:

[0041] 01-test line;

[0042] 1-protective cover, 2-safety ring, 3-grounding sleeve, 4-elastic conductive part, 5-grounding wire, 6-connecting ring, 7-pressure cover, 8-insulator, 9-terminal, 10-lead, 11-insulating thimble, 12-support insulating pin, 13-wire clamp, 14-capacitor core, 15-mounting flange. DETAILED DESCRIPTION

[0043] In order to make the purpose, advantages and features of the present invention more clear, the following is a further detailed description of a test tap structure of a high-voltage capacitor bushing proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will be more clear according to the following specific implementation methods.

[0044] See also Figures 2 to 4 The present embodiment is a test tap structure of a high-voltage capacitive bushing, which mainly includes a terminal 9, an insulator 8, a mounting flange 15, a connecting ring 6, a grounding sleeve 3, an elastic conductive member 4, a gland 7, a safety ring 2, a protective cover 1, an insulating pin 11 and a supporting insulating pin 12.

[0045] The insulator 8 is sleeved on the terminal post 9, and its upper end is shorter than the upper end of the terminal post 9, providing an installation position for subsequent components, and the lower end is longer than the lower end of the terminal post 9. The lower end of the terminal post 9 is connected to the capacitor core 14 of the high-voltage capacitor bushing through the lead 10; the mounting flange 15 is sleeved on the annular boss set on the outer wall of the insulator 8, and the mounting flange 15 is grounded.

[0046] The connecting ring 6 is specifically a connecting nut, which is sleeved on the terminal post 9 and threadedly connected thereto, and the lower side of the connecting nut abuts against the upper end of the insulator 8 .

[0047] The grounding sleeve 3 is sleeved on the terminal 9 and can slide axially along the terminal 9. A gap is set axially between the lower side of the grounding sleeve 3 and the upper side of the connecting nut. In this embodiment, the elastic conductive member 4 is specifically a spring, which is sleeved on the terminal 9 at the aforementioned gap, and its upper and lower ends are respectively connected to the grounding sleeve 3 and the connecting nut. At the same time, in order to improve the connection effect, a grounding wire 5 can be added between the grounding sleeve 3 and the connecting nut, and the grounding sleeve 3 is connected to the connecting nut through the grounding wire 5 to achieve double grounding insurance. It should be noted that the length of the grounding wire 5 here should not be shorter than the axial distance between the grounding sleeve 3 and the connecting nut on one side close to each other, so as to avoid the grounding wire 5 from breaking due to external pulling.

[0048] The gland 7 is mounted on the insulator 8. Specifically, an annular protrusion is provided at the lower end of the outer circumferential surface of the gland 7, and an axial distance is set between the lower surface of the annular protrusion and the lower end surface of the gland 7; the lower end surface of the gland 7 is in contact with the annular step plane of the insulator 8, the lower surface of the annular protrusion is in contact with the upper surface plane of the mounting flange 15, and the annular protrusion is fixedly connected to the mounting flange 15 by bolts.

[0049] An annular step is provided at the lower end of the outer circumference of the grounding sleeve 3, and the upper surface of the annular step of the grounding sleeve 3 abuts against the inner wall of the upper end of the gland 7 in the initial state. A threaded section is provided at the upper end of the outer circumference of the grounding sleeve 3, and the lower end of the threaded section is flush with the outer wall of the upper end of the gland 7 in the initial state. An axial interval is provided between the threaded section and the annular step, and the outer diameter of the grounding sleeve 3 at the threaded section is smaller than the outer diameter at the axial interval, and a grounding sleeve step is formed between the two; the interval between the outer circumference of the grounding sleeve 3 at the axial interval and the inner hole at the upper end of the gland 7 is a safety interval; the safety ring 2 is specifically a safety nut, which is sleeved on the threaded section of the grounding sleeve 3 and contacts with the plane of the outer wall of the upper end of the gland 7 to fix and limit the grounding sleeve 3.

[0050] A mounting ring groove is provided at the upper end of the outer circumferential surface of the gland 7, and the upper end of the mounting ring groove axially penetrates the upper end surface of the gland 7; an external thread is provided on the outer circumferential surface of the gland 7 at the mounting ring groove; an internal thread section matching the external thread on the gland 7 is provided on the inner circumferential surface of the protective cover 1, and a radial gap is provided between the outer circumferential surface of the safety ring 2 and the upper end outer circumferential surface of the gland 7, and the protective cover 1 is mounted on the upper end of the gland 7 at the radial gap, and its internal thread section is connected to the external thread of the gland 7.

[0051] During the test, the protective cover 1 and the safety ring 2 are not in a corresponding assembly state with the pressure cover 7 and the grounding sleeve 3; a radial mounting through hole is provided on the circumferential side of the upper end of the terminal 9, and the supporting insulating pin 12 is installed in the mounting through hole during the test to perform axial positioning of the grounding sleeve 3.

[0052] See also Figure 3 and Figure 5The insulating ejector pin 11 is a cylindrical structure with two ends open, and an annular groove is provided on the inner wall of the lower end. Two arc-shaped notches are provided on the circumferential side of the insulating ejector pin 11 at the annular groove. The two arc-shaped notches are symmetrically arranged along the circumferential direction and are arranged with a gap; the two arc-shaped notches are respectively connected to the annular groove and extend axially to the lower end of the insulating ejector pin 11; the axial size of the annular groove is adapted to the axial size of the threaded section on the grounding sleeve 3, and the outer diameter of the insulating ejector pin 11 at the annular groove is adapted to the inner hole diameter of the upper end of the gland 7; during the test, the lower end of the insulating ejector pin 11 abuts against the step of the grounding sleeve, and the bottom of the annular groove abuts against the upper end of the grounding sleeve 3. Under the action of external force, the grounding sleeve 3 is driven axially close to the connecting ring 6 by the insulating ejector pin 11 until the installation through hole is completely exposed. During the test, the upper end of the terminal 9 is connected to the test line 01 through the wire clamp 13 to achieve test measurement.

[0053] See also Figure 3 and Figure 4 During the test, you first need to unscrew the protective cover 1, and then unscrew the safety nut 2. Use the insulating thimble 11 to press the grounding sleeve 3 to the leakage position of the installation hole, and then insert the supporting insulating pin 12 into the installation hole. At this time, the annular step of the grounding sleeve 3 is separated from the gland 7, and the sleeve can be insulated from the installation flange 15. Then remove the insulating thimble 1, clamp the terminal 9 through the wire clip 13 connected to the test line 01, and the bushing dielectric loss tanδ, capacitance and partial discharge can be measured.

Claims

1. A test tap structure for a high voltage capacitive bushing, characterized in that: It comprises a terminal (9), an insulator (8), a mounting flange (15), a connecting ring (6), a grounding sleeve (3), an elastic conductive member (4), a gland (7), a safety ring (2), a protective cover (1), an insulating thimble (11) and a supporting insulating pin (12); The lower end of the terminal (9) is used to be connected to the capacitor core (14) of the high-voltage capacitor bushing through a lead wire (10); The insulator (8) is sleeved on the terminal post (9), and its upper end is shorter than the upper end of the terminal post (9), and its lower end is not shorter than the lower end of the terminal post (9); An annular boss is provided on the outer wall of the insulator (8), and the mounting flange (15) is sleeved on the annular boss on the outer wall of the insulator (8) and is grounded; The connecting ring (6) and the grounding sleeve (3) are respectively mounted on the terminal post (9), and a gap is provided between the two along the axial direction. The grounding sleeve (3) can move along the axial direction of the terminal post (9). The connecting ring (6) is fixedly mounted on the terminal post (9), and its lower end abuts against the upper end of the insulator (8). The elastic conductive member (4) is sleeved on the terminal post (9) and is located at the interval, and its two ends are respectively connected to the ground sleeve (3) and the connecting ring (6); The gland (7) is sleeved on the insulator (8), and its lower end is in contact with the annular boss and the mounting flange (15) respectively, and is fixedly connected to the mounting flange (15) through a connecting piece; The lower end of the outer circumference of the grounding sleeve (3) is provided with an annular step, the upper surface of the annular step of the grounding sleeve (3) abuts against the upper inner wall of the gland (7) in the initial state, and a safety interval is provided between the outer circumference of the grounding sleeve (3) and the upper inner hole of the gland (7), and the safety ring (2) is sleeved on the grounding sleeve (3) and contacts the upper outer wall of the gland (7); The protective cover (1) is sleeved on the upper end of the gland (7); The upper end of the terminal (9) is provided with a mounting through hole. During the test, the insulating pin (11) abuts against the upper end of the grounding sleeve (3) and is used to drive the grounding sleeve (3) axially close to the connecting ring (6) under the action of an external force until the mounting through hole is completely exposed. During the test, the supporting insulating pin (12) is installed in the mounting through hole and is used to axially position the grounding sleeve (3). During the test, the upper end of the terminal (9) is used to connect the test line (01) to achieve test measurement.

2. A test tap structure for a high voltage capacitive bushing according to claim 1, characterized in that: A threaded section is provided at the upper end of the outer circumferential surface of the grounding sleeve (3), an axial interval is provided between the threaded section and the annular step, and the outer diameter of the grounding sleeve (3) at the threaded section is smaller than the outer diameter at the axial interval, and a grounding sleeve step is formed between the two; the interval between the outer circumferential surface of the grounding sleeve (3) at the axial interval and the inner hole at the upper end of the gland (7) is the safety interval; The safety ring (2) is a safety nut, which is sleeved on the threaded section of the grounding sleeve (3); The insulating ejector pin (11) is a cylindrical structure with two ends open, and an annular groove is arranged on the inner wall of the lower end thereof. Two arc-shaped notches are arranged on the circumferential side of the insulating ejector pin (11) located at the annular groove, and the two arc-shaped notches are symmetrically arranged along the circumferential direction and are spaced apart; the two arc-shaped notches are respectively connected to the annular groove and extend axially to the lower end of the insulating ejector pin (11); The axial dimension of the inner wall of the insulating ejector pin (11) at the annular groove matches the axial dimension of the threaded section of the ground sleeve (3), and the outer diameter of the insulating ejector pin (11) at the annular groove matches the diameter of the inner hole at the upper end of the gland (7); During the test, the lower end of the insulating ejector pin (11) abuts against the step of the grounding sleeve, and the bottom of the annular groove abuts against the upper end of the grounding sleeve (3).

3. A test tap structure for a high voltage capacitive bushing according to claim 2, characterized in that: In the initial state, the lower end of the threaded section is flush with the outer wall of the upper end of the gland (7).

4. A test tap structure for a high voltage capacitive bushing according to any one of claims 1 to 3, characterized in that: The upper end of the outer peripheral surface of the gland (7) is provided with a mounting ring groove, and the upper end of the mounting ring groove extends axially to the upper end surface of the gland (7); The outer peripheral surface of the gland (7) located at the mounting ring groove is provided with an external thread; The inner circumferential surface of the protective cover (1) is provided with an internal thread section that matches the external thread on the gland (7), and the internal thread section of the protective cover (1) is connected to the external thread of the gland (7).

5. A test tap structure for a high voltage capacitive bushing according to claim 4, characterized in that: An annular protrusion is provided at the lower end of the outer peripheral surface of the gland (7), and an axial distance is provided between the lower surface of the annular protrusion and the lower end surface of the gland (7); The lower end surface of the gland (7) is in plane contact with the upper surface of the annular step of the insulator (8), the lower surface of the annular protrusion is in plane contact with the upper surface of the mounting flange (15), and the annular protrusion is fixedly connected to the mounting flange (15) by bolts.

6. A test tap structure for a high voltage capacitive bushing according to any one of claims 1 to 3, characterized in that: The grounding sleeve (3) and the connecting ring (6) are connected via a grounding wire (5).

7. A test tap structure for a high voltage capacitive bushing according to claim 6, characterized in that: The elastic conductive member (4) is a spring, and the connecting ring (6) is a connecting nut.

8. The test tap structure of a high voltage capacitive bushing according to claim 1, characterized in that: During a test, the upper end of the terminal (9) can be connected to a test line (01) via a line clip (13).

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