HIGH VOLTAGE LOAD SWITCH USING MAGNETIC BLOWOUT COMPOSITE ARC EXTINGUISHING

Abstract

 The present invention relates to a high-voltage load switch with magnetic blowout composite arc extinguishing capability, including a rear fixing plate and a front fixing plate, wherein between the rear fixing plate and the front fixing plate, an upper beam is mounted on the upper right, a lower beam is mounted on the lower right, and a grounding beam is mounted on the lower left; a plurality of upper insulators are arranged at intervals on the upper beam; a plurality of isolation contacts are mounted correspondingly on the plurality of upper insulators; and a copper-tungsten alloy arc-directing pin and an arc-directing closure assembly are provided on a lower side of each isolation contact. In the present invention, permanent magnets and arc chutes are used in combination for arc extinguishing. At the time of moving contact opening, an arc is blown to gaps in an arc-directing closure assembly under the action of magnetism, and the arc-directing closure assembly generates an electromagnetic force perpendicular to a moving trajectory of the arc, such that under the action of the electromagnetic force, the arc is split into multiple segments, lengthened and rapidly cooled, and energy of the arc is absorbed, forcing the arc be to extinguished or preventing its reignition after a zero crossing point, so the arc extinguishing effect is significantly improved. The present invention has the advantages of timely arc extinction response and strong arc extinction capability. The high-voltage load switch has a smaller overall volume and lowered cost, and is safer and more reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage switchgear, in particular to a high-voltage load switch with magnetic blowout composite arc extinguishing capability.

Background of the Invention

[0002] A high-voltage load switch is an important component of high-voltage switchgear in an electric power system, and is widely used in industrial and civil power generation and distribution systems and power supply terminals.

[0003] A process of making and breaking current by contacts is accompanied by a phenomenon of gas discharge, i.e. an electric arc. The electric arc has concentrated energy and very high temperature, leading to fusion at fusion welding and contact locations of the contacts in severe cases.

[0004] Existing common means for arc extinguishing are arc chutes, arc extinguishing rings, magnetic blowout, air blast and so on. However, arc chutes and arc extinguishing rings have limited arc extinguishing capability. Besides, in order to achieve an effect, the number of arc chute sheets and the number of copper tape turns of an arc extinguishing ring need to be increased. Moreover, to ensure insulation, an isolation break distance can only be increased, which will lead to a wider and taller gas compartment, thereby increasing material costs. Traditional magnetic blowout and air blast modes also have the problems of a large volume, a complex structure, and a high cost, making them unsuitable for use in ring main units that are small in size and compact in structure.

Summary of the Invention

[0005] In order to solve the technical problems mentioned in the background art, the present invention provides a high-voltage load switch with magnetic blowout composite arc extinguishing capability.

[0006] The present invention adopts the following technical solution: a high-voltage load switch with magnetic blowout composite arc extinguishing capability, including a rear fixing plate and a front fixing plate, wherein between the rear fixing plate and the front fixing plate, an upper beam is mounted on the upper right, a lower beam is mounted on the lower right, and a grounding beam is mounted on the lower left; a plurality of upper insulators are arranged at intervals on the upper beam; a plurality of isolation contacts are mounted correspondingly on the plurality of upper insulators; a plurality of lower insulators are arranged at intervals on the lower beam; the plurality of lower insulators correspond to the plurality of upper insulators; a conductive rod is mounted on each of the lower insulators; the conductive rod is pin-connected to a movable blade assembly; a busbar is mounted on the grounding beam; a plurality of grounding contacts are arranged at intervals on the busbar; the movable blade assembly is pin-connected to a connecting plate by an insulating sleeve; the connecting plate is pin-connected to an insulating shaft by a crank arm; a tail end of the insulating shaft is connected to the rear fixing plate by a bearing; a front end of the insulating shaft passes through a corresponding hole of the front fixing plate and is connected to a drive mechanism; a copper-tungsten alloy arc-directing pin and an arc-directing closure assembly are provided on a lower side of the isolation contact; and the arc-directing closure assembly is located on an upper side of the copper-tungsten alloy arc-directing pin.

[0007] Further, the arc-directing closure assembly includes a plurality of magnetic guide sheets, plastic rivets , a cross-shaped grid frame, a pair of magnetic compartments, and a pair of permanent magnets; the plurality of magnetic guide sheets are arranged in an array on two sides of the cross-shaped grid frame; the pair of magnetic compartments are respectively provided on the two sides of the cross-shaped grid frame and are located on outer sides of the magnetic guide sheets that are on the two sides; the pair of permanent magnets are respectively mounted in the pair of magnetic compartments; and the plastic rivets are pressed into the magnetic compartments to limit positions of the permanent magnets.

[0008] Further, the cross-shaped grid frame is injection molded from a thermoplastic engineering plastic, with a long grid frame rod in vertical orientation at a lower side; a center arc trajectory of the grid frame rod maintains a same curvature as a movement trajectory of a contact of the movable blade assembly; grid frame wings are provided in horizontal orientation at left and right sides, on an upper side of the grid frame rod; a short grid frame head is provided in vertical orientation at an upper side; and the grid frame head is fixedly provided on a central fixing plate on a front end of the isolation contact, so that the pair of grid frame wings are distributed on left and right sides of the central fixing plate.

[0009] Further, the magnetic guide sheet is H-shaped, and is provided with a snap-fit notch as an upper notch, for assembly in clamping slots on two sides of the gate frame rod; arc guide channels are stamped on three edges of a lower notch of the magnetic guide sheet; and splash-proof stoppers are formed by bending at outer sides of two legs at the bottom of the magnetic guide sheet.

[0010] Further, the magnetic guide sheet is made of an easily magnetizable metal material and is coated with a graphene-containing coating on a surface thereof.

[0011] Further, the magnetic compartment is injection molded from an engineering thermoplastic and is in the shape of a square tube overall, and is provided at a front end with a snap-fit sheet that is snap-fit in a slot of the grid frame wing; a cavity of the magnetic compartment is a compartment core with an open tail end, for installing the permanent magnet; and the tail of the magnetic compartment is provided with a fixing hole for inserting the plastic rivet.

[0012] Further, the permanent magnet is a samarium cobalt magnet, an outer surface of which is partially encapsulated in a metal casing.

[0013] Further, the pair of the permanent magnets after installation are placed at an angle of 19° to 30° with respect to a horizontal plane.

[0014] Further, the copper-tungsten alloy arc-directing pin is welded on the grounding contact.

[0015] Compared with the prior art, the present invention has advantages as follows: according to the high-voltage load switch with magnetic blowout composite arc extinguishing capability designed in the present invention, a traditional arc extinction design is abandoned, while permanent magnets and arc chutes are used in combination for arc extinguishing. At the time of moving contact opening, an arc is blown to gaps in an arc-directing closure assembly under the action of magnetism, and the arc-directing closure assembly generates an electromagnetic force perpendicular to a moving trajectory of the arc, such that under the action of the electromagnetic force, the arc is split into multiple segments, lengthened and rapidly cooled, and energy of the arc is absorbed, forcing the arc be to extinguished or preventing its reignition after a zero crossing point while accelerating extinguishing of the arc, so the arc extinguishing effect is significantly improved. The present invention has the advantages of timely arc extinction response and strong arc extinction capability. Moreover, the high-voltage load switch has a smaller overall volume, a simple structure and a lowered cost, and is safer and more reliable.

Brief Description of the Drawings

[0016] 

Fig. 1 is a schematic diagram of an overall structure of a high-voltage load switch with magnetic blowout composite arc extinguishing capability adopted in the present invention;

Fig. 2 is a front schematic diagram of a high-voltage load switch a high-voltage load switch with magnetic blowout composite arc extinguishing capability adopted in the present invention;

Fig. 3 is a left view of a high-voltage load switch with magnetic blowout composite arc extinguishing capability adopted in the present invention;

Fig. 4 is a schematic diagram of an overall structure of an arc-directing closure assembly in the present invention;

Fig. 5 is a schematic diagram of an overall structure of a magnetic guide sheet in the present invention;

Fig. 6 is a schematic diagram of an overall structure of a cross-shaped grid frame in the present invention;

Fig. 7 is a schematic diagram of an overall structure of a magnetic compartment in the present invention;

Fig. 8 is a schematic diagram of an overall structure of a permanent magnet in the present invention; and

Fig. 9 is a schematic diagram of an overall structure of an isolation contact in the present invention.

[0017] Reference numerals:

1 - rear fixing plate, 2 - upper beam,

3 - upper insulator, 4 - isolation contact,

5 - crank arm, 6 - insulating shaft,

7 - front fixing plate, 8 - connecting plate,

9 - lower insulator, 10 - conductive rod,

11 - insulating sleeve, 12 - movable blade assembly,

13 - grounding beam, 14 - grounding contact,

15 - busbar, 16 - arc-directing closure assembly,

17 - lower beam, 18 - bearing,

19 - permanent magnet, 20 - copper-tungsten alloy arc-directing pin,

16-1 - magnetic guide sheet,

16-1-1 - snap-fit notch, 16-1-2 - arc guide channel,

16-1-3 - stopper,

16-2 - plastic rivet,

16-3 - cross-shaped grid frame,

16-3-1 - grid frame rod, 16-3-2 - grid frame wing,

16-3-3 - grid frame head,

16-4 - magnetic compartment,

16-4-1 - snap-fit sheet, 16-4-2 - compartment core,

16-4-3 - fixing hole.

Detailed Description of Embodiments

[0018] In the following, to facilitate understanding of the technical solution of the present invention by those skilled in the art, further description is provided with reference to the accompanying drawings. It should be understood that such description is merely exemplary and not intended to limit the scope of the present invention.

[0019] In the following detailed description, for ease of explanation, many specific details are set forth to provide a full understanding of embodiments of the present invention. However, it is evident that one or more embodiments may also be implemented without such specific details. In addition, in the following description, description of well-known structures and technology are omitted to avoid unnecessary confusion of concepts in the present invention.

[0020] As shown in Figs. 1 to 3 and 9, the present invention adopts a high-voltage load switch with magnetic blowout composite arc extinguishing capability, which includes a rear fixing plate 1 and a front fixing plate 7. Between the rear fixing plate 1 and the front fixing plate 7, an upper beam 2 is mounted on the upper right, a lower beam 17 is mounted on the lower right, and a grounding beam 13 is mounted on the lower left. Upper insulators 3 are mounted on the upper beam 2; isolation contacts 4 are mounted on the upper insulators 3; lower insulators 9 are mounted on the lower beam 17; a conductive rod 10 is mounted on each of the lower insulators 9; and the conductive rod 10 is pin-connected to a movable blade assembly 12. A busbar 15 is mounted on the grounding beam 13, and grounding contacts 14 are mounted on the busbar 15. The movable blade assembly 12 is pin-connected to a connecting plate 8 by an insulating sleeve 11; the connecting plate 8 is pin-connected to an insulating shaft 6 by a crank arm 5; a tail end of the insulating shaft 6 is connected to the rear fixing plate 1 by a bearing 18; and a front end of the crank arm 5 passes through a corresponding hole of the front fixing plate 7 and is connected to a mechanism by linkage of the insulating shaft 6.

[0021] Specifically, when the high-voltage load switch is used as an isolating switch, the insulating shaft 6 rotates under the drive of the mechanism, causing the movable blade assembly 12 to rotate and come into contact with the isolation contact 4 under pressure, thereby achieving isolation closing and circuit conduction. Under the drive of the mechanism, the insulating shaft 6 rotates, causing the movable blade assembly 12 to separate from the isolation contact 4, thereby achieving isolation opening and circuit breaking. Under the drive of the mechanism, the insulating shaft 6 rotates, causing the movable blade assembly 12 to come into contact with the grounding contact 14 under pressure, thereby achieving grounding closing and circuit grounding.

[0022] Specifically, when the high-voltage load switch is used as a load switch, a copper-tungsten alloy arc-directing pin 20 is ultrasonically welded on the isolation contact 4, and then an arc-directing closure assembly 16 is mounted on the isolation contact. The arc-directing closure assembly 16 is located on an upper side of the copper-tungsten alloy arc-directing pin 20. As shown in Fig. 4, the arc-directing closure assembly 16 is composed of magnetic guide sheets 16-1, plastic rivets 16-2, a grid frame 16-3, magnetic compartments 16-4, and permanent magnets 19.

[0023] In specific implementation, as shown in Fig. 5, the magnetic guide sheet 16-1 is H-shaped, and is provided with a snap-fit notch 16-1-1 as an upper notch, arc guide channels 16-1-2 stamped on three edges of a lower notch, and stoppers 16-1-3 formed by bending at outer sides of two legs in order to prevent arc splashing. This embodiment includes an arrangement of 12 magnetic guide sheets with a curved arc guide channel design. The magnetic guide sheet 16-1 is made of an easily magnetizable metal material, and functions to generate a strong magnetic field after being magnetized, thereby attracting an electric arc into the arc guide channels 16-1-2.

[0024] As shown in Fig. 6, the cross-shaped grid frame 16-3 is injection molded from an engineering thermoplastic, with a long grid frame rod 16-3-1 in vertical orientation at a lower side. A center arc trajectory of the grid frame rod 16-3-1 maintains a same curvature as a movement trajectory of a contact of the movable blade assembly 12, so that an arc-directing point trajectory of the contact is always at a constant arc-directing angle with respect to the arc-directing closure assembly. Grid frame wings 16-3-2 are provided in horizontal orientation at left and right sides, and a short grid frame head 16-3-3 is provided in vertical orientation at an upper side. The grid frame head 16-3-3 is fixedly provided on a central fixing plate on a front end of the isolation contact 4, so that the pair of grid frame wings 16-3-2 are distributed on left and right sides of the central fixing plate.

[0025] As shown in Fig. 7, the magnetic compartment 16-4 is also injection molded and is in the shape of a square tube, with a snap-fit sheet 16-4-1 at a front part, a compartment core 16-4-2 as a cavity, and a fixing hole 16-4-3 at the tail. Specific installation is as follows: the snap-fit notch 16-1-1 constituting the magnetic guide sheet 16-1 is snap-fit into slots of the grid frame rod 16-3-1 constituting the grid frame 16-3, and a plurality of magnetic guide sheets 16-1 are arranged at equal intervals and spaced apart equally from the movement trajectory of the movable blade assembly 12; the snap-fit sheets 16-4-1 constituting the magnetic compartments 16-4 are snap-fit into slots of the grid frame wings 16-3-2 constituting the grid frame 16-3; the permanent magnets 19 are installed inside the compartment cores 16-4-2 constituting the magnetic compartments 16-4; and the plastic rivets 16-2 are pressed into the fixing holes 16-4-3 constituting the magnetic compartments 16-4 for positional limiting.

[0026] The arc-directing closure assembly 16 is fixedly connected to the isolation contact 4 by means of the grid frame head 16-3-3 constituting the grid frame 16-3. When the movable blade assembly 12 in a live state separates instantly from the isolation contact 4, an arc is inevitably formed between the movable blade assembly 12 and the isolation contact 4, which will cause erosion or burning down the movable blade assembly 12 and the isolation contact 4 in severe cases. At that time, rapid extinguishing of the arc is very necessary. The present invention adopts a magnetic blowout and arc chute composite arc-extinguishing mode. The arc is blown to gaps between the magnetic guide sheets 16-1 under the effect of magnetism, such that the arc is cut into multiple segments, lengthened and rapidly cooled. The cavity is coated with a graphene-containing coating, which can absorb energy of the arc, forcing the arc be to extinguished or preventing its reignition after a zero-crossing point. As shown in Fig. 8, the permanent magnets 19 are placed in the compartment cores 16-4-2 of the left and right magnetic compartments 16-4, and their centers are at an angle of 19° to 30° with respect to a horizontal plane, and specifically may be set to an angle of 15°, and their magnetic orientations are same. Magnetic forces are superimposed at the moving trajectory of the movable blade assembly 12 to produce an electromagnetic force perpendicular to a moving trajectory of the arc, such that the arc is pushed into the arc guide channels 16-1-2 of the magnetic guide sheets 16-1 under the action of the electromagnetic force, and the arc is split into multiple segments and lengthened, which accelerates extinguishing of the arc. The permanent magnets 19 may be samarium cobalt magnets, with the characteristics of high temperature resistance and resistance to demagnetization.

[0027] In summary, according to the high-voltage load switch with magnetic blowout composite arc extinguishing capability designed in the present invention, a traditional arc extinction design is abandoned, while permanent magnets and arc chutes are used in combination for arc extinguishing. At the time of moving contact opening, an arc is blown to gaps in an arc-directing closure assembly under the action of magnetism, and the arc-directing closure assembly generates an electromagnetic force perpendicular to a moving trajectory of the arc, such that under the action of the electromagnetic force, the arc is split into multiple segments, lengthened and rapidly cooled, and energy of the arc is absorbed, forcing the arc be to extinguished or preventing its reignition after a zero crossing point while accelerating extinguishing of the arc, so the arc extinguishing effect is significantly improved. The present invention has the advantages of timely arc extinction response and strong arc extinction capability. Moreover, the high-voltage load switch has a smaller overall volume, a simple structure and a lowered cost, and is safer and more reliable.

[0028] The above embodiments are merely description of preferred embodiments of the present invention, and are not limitations on the scope of the present invention. Various modifications and improvements to the technical solution of the present invention made by those of ordinary skill in the art without departing from the design spirit of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A high-voltage load switch with magnetic blowout composite arc extinguishing capability, comprising a rear fixing plate (1) and a front fixing plate (7), wherein between the rear fixing plate (1) and the front fixing plate (7), an upper beam (2) is mounted on the upper right, a lower beam (17) is mounted on the lower right, and a grounding beam (13) is mounted on the lower left; a plurality of upper insulators (3) are arranged at intervals on the upper beam (2); a plurality of isolation contacts (4) are mounted correspondingly on the plurality of upper insulators (3); a plurality of lower insulators (9) are arranged at intervals on the lower beam (17); the plurality of lower insulators (9) correspond to the plurality of upper insulators (3); a conductive rod (10) is mounted on each of the lower insulators (9); the conductive rod (10) is pin-connected to a movable blade assembly (12); a busbar (15) is mounted on the grounding beam (13); a plurality of grounding contacts (14) are arranged at intervals on the busbar (15); the movable blade assembly (12) is pin-connected to a connecting plate (8) by an insulating sleeve (11); the connecting plate (8) is pin-connected to an insulating shaft (6) by a crank arm (5); a tail end of the insulating shaft (6) is connected to the rear fixing plate (1) by a bearing (18); a front end of the insulating shaft (6) passes through a corresponding hole of the front fixing plate (7) and is connected to a drive mechanism; a copper-tungsten alloy arc-directing pin (20) and an arc-directing closure assembly (16) are provided on a lower side of the isolation contact (4); and the arc-directing closure assembly (16) is located on an upper side of the copper-tungsten alloy arc-directing pin (20).

2. The high-voltage load switch with magnetic blowout composite arc extinguishing capability according to claim 1, wherein the arc-directing closure assembly (16) comprises a plurality of magnetic guide sheets (16-1), plastic rivets (16-2), a cross-shaped grid frame (16-3), a pair of magnetic compartments (16-4), and a pair of permanent magnets (19); the plurality of magnetic guide sheets (16-1) are arranged in an array on two sides of the cross-shaped grid frame (16-3); the pair of magnetic compartments (16-4) are respectively provided on the two sides of the cross-shaped grid frame (16-3) and are located on outer sides of the magnetic guide sheets (16-1) that are on the two sides; the pair of permanent magnets (19) are respectively mounted in the pair of magnetic compartments (16-4); and the plastic rivets (16-2) are pressed into the magnetic compartments (16-4) to limit positions of the permanent magnets (19).

3. The high-voltage load switch with magnetic blowout composite arc extinguishing capability according to claim 2, wherein the cross-shaped grid frame (16-3) is injection molded from a thermoplastic engineering plastic, with a long grid frame rod (16-3-1) in vertical orientation at a lower side; a center arc trajectory of the grid frame rod (16-3-1) maintains a same curvature as a movement trajectory of a contact of the movable blade assembly (12); grid frame wings (16-3-2) are provided in horizontal orientation at left and right sides, on an upper side of the grid frame rod (16-3-1); a short grid frame head (16-3-3) is provided in vertical orientation at an upper side; and the grid frame head (16-3-3) is fixedly provided on a central fixing plate on a front end of the isolation contact (4), so that the pair of grid frame wings (16-3-2) are distributed on left and right sides of the central fixing plate.

4. The high-voltage load switch with magnetic blowout composite arc extinguishing capability according to claim 3, wherein the magnetic guide sheet (16-1) is H-shaped, and is provided with a snap-fit notch (16-1-1) as an upper notch, for assembly in clamping slots on two sides of the gate frame rod (16-3-1); arc guide channels (16-1-2) are stamped on three edges of a lower notch of the magnetic guide sheet; and splash-proof stoppers (16-1-3) are formed by bending at outer sides of two legs at the bottom of the magnetic guide sheet (16-1).

5. The high-voltage load switch with magnetic blowout composite arc extinguishing capability according to claim 4, wherein the magnetic guide sheet (16-1) is made of an easily magnetizable metal material and is coated with a graphene-containing coating on a surface thereof.

6. The high-voltage load switch with magnetic blowout composite arc extinguishing capability according to claim 5, wherein the magnetic compartment (16-4) is injection molded from an engineering thermoplastic and is in the shape of a square tube overall, and is provided at a front end with a snap-fit sheet (16-4-1) to be snap-fit in a slot of the grid frame wing (16-3-2); a cavity of the magnetic compartment is a compartment core (16-4-2) with an open tail end, for installing the permanent magnet (19); and the tail of the magnetic compartment is provided with a fixing hole (16-4-3) for inserting the plastic rivet (16-2).

7. The high-voltage load switch with magnetic blowout composite arc extinguishing capability according to claim 6, wherein the permanent magnet (19) is a samarium cobalt magnet, an outer surface of which is partially encapsulated in a metal casing.

8. The high-voltage load switch with magnetic blowout composite arc extinguishing capability according to claim 7, wherein the pair of the permanent magnets (19) after installation are placed at an angle of 19° to 30° with respect to a horizontal plane.

9. The high-voltage load switch with magnetic blowout composite arc extinguishing capability according to claim 8, wherein the copper-tungsten alloy arc-directing pin (20) is welded on the grounding contact (14).

Drawing