A load switch with better electrical insulation

Abstract

The utility model provides a kind of better load switch of electrical insulation performance, including switch frame, first insulator and second insulator being set in the corresponding position of switch frame upper and lower, main shaft and ground static contact, main knife static contact is set in the lower surface of first insulator, movable contact seat is set in the upper surface of second insulator, the load switch further include movable contact, push rod, wherein, one end of the push rod is connected with the main shaft, the other end is connected with the movable contact, one end of the movable contact is hinged on the movable contact seat, the main shaft can drive the other end of the movable contact to move between the ground static contact and main knife static contact by push rod.The utility model has the beneficial effects that: the utility model can increase the distance of electrified body and switch frame, increase electrical creepage, effectively improve the electrical insulation performance of load switch.

Description

Technical Field

[0001] This utility model relates to the field of high and medium voltage power transmission and distribution application technology, specifically to a load switch with better electrical insulation performance. Background Technology

[0002] 24kV ring main units are widely used in urban and industrial power distribution networks, providing reliable power supply for both indoor and outdoor distribution. Furthermore, 24kV ring main units can be used in conjunction with other power facilities such as transformers and cables to construct a complete power grid system. Load switches are a crucial component of ring main units.

[0003] As power switchgear, insulation performance is one of its key parameters. The State Grid and Southern Power Grid have strict requirements for parameters such as power frequency withstand voltage, lightning impulse resistance, and partial discharge, which are mandatory inspection items for all user units. Most existing 24kV SF6 load switches have insufficient margin to some extent and unstable insulation performance, mainly exhibiting the following defects:

[0004] 1. The contact seat of the fixed moving contact is mounted on a plastic crossbeam, which in turn is mounted on a metal crossbeam. The plastic crossbeam has insufficient electrical insulation performance, resulting in unstable electrical insulation.

[0005] 2. The plastic crossbeam has a limited height, and its creepage distance relative to 24kV is almost at its limit. Therefore, it cannot reliably achieve electrical insulation performance.

[0006] Therefore, it is necessary to improve the existing 24kV SF6 load switch to enhance its electrical insulation performance. Utility Model Content

[0007] To address the problems in the existing technology, this utility model provides a load switch with better electrical insulation performance, making the improved load switch safer.

[0008] This utility model relates to a load switch with improved electrical insulation performance, comprising a switch frame, a first and second insulator, a main shaft, and a grounding stationary contact disposed at corresponding positions on the upper and lower parts of the switch frame, a main blade stationary contact disposed on the lower surface of the first insulator, and a moving contact seat disposed on the upper surface of the second insulator. The load switch further comprises a moving contact and a push rod, wherein one end of the push rod is connected to the main shaft, and the other end is connected to the moving contact. One end of the moving contact is hinged to the moving contact seat, and the main shaft can drive the other end of the moving contact to move between the grounding stationary contact and the main blade stationary contact via the push rod.

[0009] Furthermore, the first insulator is an insulator with a creeper skirt, the switch frame includes a metal upper crossbeam, and the main blade stationary contact is fixed below the upper crossbeam by the first insulator.

[0010] Furthermore, the second insulator is an insulator with a creeper skirt, the switch frame includes a lower metal crossbeam, and the moving contact seat is fixed above the lower metal crossbeam by the second insulator, corresponding to the position of the main blade stationary contact in the projection direction.

[0011] Furthermore, the lower metal beam has an extension frame near the second insulator, and the grounding stationary contact is mounted on the extension frame.

[0012] Furthermore, the load switch includes a three-phase switching unit. Each phase switching unit includes a first insulator, a second insulator, a main blade stationary contact, a grounding stationary contact, a moving contact seat, a moving contact, and a push rod. The three push rods are arranged side by side on the main shaft and are linked with the main shaft.

[0013] Furthermore, the load switch is a 24kV load switch.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: by fixing the main blade stationary contact with the first insulator and then mounting the first insulator on the metal switch frame, the distance between the live body and the ground is increased. The moving contact seat that fixes the moving contact is changed to be mounted on the second insulator, and the second insulator is then mounted on the metal switch frame, which increases the distance between the live body and the switch frame. The setting of the first and second insulators increases the electrical creepage distance and better ensures the insulation parameters of the switch.

[0015] Insulators are relatively easier to control in terms of partial discharge characteristics, and can more conveniently meet the operation requirements of 24kV switches. In addition, under the premise that the installation space does not exceed the standard SF610kV switchgear dimensions, increasing the vertical distance between the upper and lower crossbeams and setting the first and second insulators can increase the length of the moving contact arm, so that the contact opening distance is larger when the same opening angle is reached, which can further improve the reliability of the equipment.

[0016] The use of insulators with shed skirts can effectively increase the electrical creepage distance, thereby further improving the electrical insulation performance. Attached Figure Description

[0017] To more clearly illustrate the solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2This is a schematic diagram of the structure of this utility model from another perspective;

[0020] Figure 3 for Figure 2 A schematic diagram of the moving contact position in the open state, shown in the AA cross-sectional view of the circuit breaker;

[0021] Figure 4 A schematic diagram showing the position of the moving contact when the circuit is closed;

[0022] Figure 5 This is a schematic diagram showing the position of the moving contact when the device is in the grounded state. Detailed Implementation

[0023] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order.

[0024] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment to other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0026] like Figures 1-3 As shown, in a preferred embodiment of this utility model, this example is a three-position 24kV load switch. The load switch of this utility model includes a switch frame 1, an upper crossbeam disposed above the switch frame 1, a lower metal crossbeam 9 disposed below the switch frame 1, and a main shaft 4 disposed in the middle of the switch frame 1. Three-phase switch units are arranged in parallel on the switch frame 1. Each phase switch unit includes a first insulator 2, a second insulator 8, a main knife stationary contact 3, a grounding stationary contact 7, a moving contact seat 10, a moving contact 6, and a push rod. The three push rods are arranged in parallel on the main shaft 4 and are linked with the main shaft 4.

[0027] Three first insulators 2 are fixed side by side on the lower surface of the upper crossbeam, and three second insulators 8 are fixed side by side on the lower metal crossbeam 9. The upper and lower positions of the first insulators 2 and the second insulators 8 are corresponding. Since the structure of the three-phase switch unit is the same in this example, this example will be explained using one of the phase switch units as an example.

[0028] In this example, the main blade stationary contact 3 is located on the lower surface of the first insulator 2, and the moving contact seat 10 is located on the upper surface of the second insulator 8. One end of the push rod 5 is connected to the main shaft 4 through a first hinge structure, and the other end is connected to the middle of the moving contact 6 through a second hinge mechanism. One end of the moving contact 6 is hinged to the moving contact seat 10. The main shaft 4 can drive the other end of the moving contact 6 to move between the grounding stationary contact 7 and the main blade stationary contact 3 through the push rod. When the main shaft is driven by the operating mechanism through a dynamic engagement, it pushes the push rod to move.

[0029] like Figure 3 As shown, when the switch is initially in the open state, the other end of the moving contact 6 is positioned between the grounding stationary contact 7 and the main blade stationary contact 3. When the moving contact is pushed counterclockwise by the main shaft 4, the other end of the moving contact 6 contacts the main blade stationary contact 3, thus closing the circuit. The position of the moving contact 6 is as follows: Figure 4 As shown, when the moving contact 6 is pushed clockwise, the other end of the moving contact 6 contacts the grounding stationary contact 7, thus achieving grounding. The position of the moving contact 6 is as follows. Figure 5 As shown, this enables operation at three workstations.

[0030] Compared to conventional structures, this invention effectively increases the distance between the live conductor and the switch housing. Specifically, it increases the vertical distance between the upper and lower crossbeams. The main blade stationary contact is fixed by a first insulator, which is then mounted on a metal switch frame, increasing the distance between the live conductor and the ground. The moving contact seat, which fixes the moving contact, is instead mounted on a second insulator, which is then mounted on the metal switch frame, further increasing the distance between the live conductor and the switch frame. The arrangement of the first and second insulators increases the electrical creepage distance, better ensuring the insulation parameters of the switch.

[0031] Insulators are relatively easier to control in terms of partial discharge characteristics, making it easier to meet the operation requirements of 24kV switches. In addition, under the premise that the installation space does not exceed the standard SF610kV switchgear dimensions, the length of the moving contact arm can be increased by setting the first and second insulators, so that the contact opening distance is larger when the switch is opened at the same angle, and the stop position of the switch after opening is farther away from the stationary contact, thus making the switch safer and more reliable.

[0032] Preferably, in this example, the first insulator 2 is an insulator with creepage-enhancing skirts, the second insulator 8 is an insulator with creepage-enhancing skirts, the upper crossbeam and the lower metal crossbeam 9 of the switch frame 1 are both made of conductive metal, the moving contact seat 10 is fixed above the lower metal crossbeam 9 by the second insulator 8, and corresponds to the position of the main blade stationary contact 3 in the projection direction. Through the insulator structure with skirts, the electrical creepage distance can be effectively increased, and the electrical insulation performance can be further improved.

[0033] Preferably, the lower metal beam 9 is provided with an extension frame capable of conducting electricity near the second insulator 8, and the grounding stationary contact 7 is disposed on the extension frame, thereby ensuring that the grounding stationary contact 7 is reliably grounded.

[0034] As can be seen from the above, this utility model has the following beneficial effects:

[0035] 1. Compared with conventional structures, it can increase the distance between the live parts and the switch housing, thereby improving its insulation performance;

[0036] 2. The moving contact seat of the fixed moving contact is mounted on the second insulator, which increases the electrical creepage distance and improves electrical reliability;

[0037] 3. The length of the moving contact of the switch has been increased, so that the stop position of the switch after opening is farther from the stationary contact, making the switch safer and more reliable;

[0038] 4. After the rated voltage level is increased, the switch cabinet is the same size as the 10kV switch cabinet, without increasing the installation space.

[0039] The specific embodiments described above are preferred embodiments of this utility model, and are not intended to limit the specific scope of this utility model. The scope of this utility model includes but is not limited to the specific embodiments described above. All equivalent changes made in accordance with this utility model are within the protection scope of this utility model.

Claims

1. A load switch with improved electrical insulation performance, characterized in that: The load switch includes a switch frame, a first and second insulator, a main shaft, and a grounding stationary contact, all positioned at corresponding positions on the upper and lower parts of the switch frame. A main blade stationary contact is located on the lower surface of the first insulator, and a moving contact seat is located on the upper surface of the second insulator. The load switch also includes a moving contact and a push rod. One end of the push rod is connected to the main shaft, and the other end is connected to the moving contact. One end of the moving contact is hinged to the moving contact seat. The main shaft can drive the other end of the moving contact to move between the grounding stationary contact and the main blade stationary contact via the push rod.

2. The load switch with improved electrical insulation performance according to claim 1, characterized in that: The first insulator is an insulator with a creeper skirt, the switch frame includes a metal upper crossbeam, and the main blade stationary contact is fixed below the upper crossbeam by the first insulator.

3. The load switch with improved electrical insulation performance according to claim 2, characterized in that: The second insulator is an insulator with climbing skirts. The switch frame includes a lower metal crossbeam. The moving contact seat is fixed above the lower metal crossbeam by the second insulator and corresponds to the position of the main blade stationary contact in the projection direction.

4. The load switch with improved electrical insulation performance according to claim 3, characterized in that: The lower metal beam has an extension frame near the second insulator, and the grounding stationary contact is mounted on the extension frame.

5. The load switch with improved electrical insulation performance according to any one of claims 1-4, characterized in that: The load switch includes a three-phase switching unit. Each phase switching unit includes a first insulator, a second insulator, a main blade stationary contact, a grounding stationary contact, a moving contact seat, a moving contact, and a push rod. The three push rods are arranged side by side on the main shaft and are linked with the main shaft.

6. The load switch with improved electrical insulation performance according to any one of claims 1-4, characterized in that: The load switch is a 24kV load switch.

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