CN106571262A - Isolation switch and contact assembly thereof - Google Patents

Abstract

The invention relates to an isolating switch and its contact assembly. The contact assembly includes a main contact and an arc contact. The main contact is provided with an insulating support. The arc contact is arranged on the insulating support. The arc contact The arc extinguishing coil wound around the insulating support is electrically connected to the main contact, thereby ensuring that the current can flow through the arc contact, coil, and main contact in sequence, ensuring the magnetic field strength in the coil, and further improving the arc extinguishing effect , and minimize the impact of arcing contact shunting, and further, it is only necessary to arrange arcing contacts with a small structure at the end of the arc extinguishing coil, and the cost is low.

Description

An isolating switch and its contact assembly

technical field

The invention relates to the field of high-voltage switches, in particular to an isolating switch and a contact assembly thereof.

Background technique

In a double-bus GIS, usually a single bus is operated. When the bus needs to be changed, due to the difference between the two buses, the disconnector needs to have the switching current and switching voltage of the bus, especially in ultra-high voltage. The double busbars are long, the current capacity is large, and the difference between the two busbars is large, which leads to the bus switching current at the beginning of the disconnector up to 1600A, and the voltage up to 400V, which puts forward strict requirements for the disconnector, which requires the disconnector Very strong arc extinguishing ability, the traditional way is mainly to increase the opening and closing speed of the isolating switch, thereby improving the breaking ability of the isolating switch to the bus conversion current, but this requires the mechanism of the isolating switch to operate with a very large output power, which will cause The isolating switch mechanism has a relatively high scale, and the opening and closing process of the isolating switch has a large vibration and low reliability.

A Chinese invention patent document with the authorized announcement number CN105428138A discloses a high-voltage isolating switch, which includes a moving arc contact and a static arc contact, both of which are arc contacts, and the moving arc contact is wound with a useful The arc extinguishing coil that generates a magnetic field when the brake is opened, the moving arc contact is fixedly connected to the moving main contact by bolts, the moving main contact and the static main contact are both main contacts, and the busbar is disconnected in the disconnector In the process of converting the current, an arc is generated between the moving arc contact and the static arc contact, and the arc current enters the arc extinguishing coil to form a magnetic field. The arc starts to rotate and is elongated under the action of the magnetic field. Under the action of SF6 It can be cooled quickly, and finally the arc is safely extinguished when the current crosses zero, thus achieving the purpose of magnetic blowing out the arc. However, when the isolating switch is used to break the bus conversion current, since the arc extinguishing coil is sleeved on the moving arc contact and the moving arc contact is fixed on the moving main contact, it is equivalent to the parallel connection of the moving arc contact and the coil to the moving main contact. On the contact, when the electric arc is generated and a high current is formed in this way of electrical connection, the current will inevitably be shunted by the arc contact during the process of the current flowing through the coil to form a magnetic field, so that the arc extinguishing effect of the arc extinguishing coil does not reach a higher level. Good effect, in addition, the manufacturing cost of the moving arcing contact is relatively high, and all the moving arcing contacts are used on the moving main contact, which increases the cost of the isolating switch.

Contents of the invention

The purpose of the present invention is to provide a disconnector to solve the problem of shunting current by the movable arc contact when the parallel connection between the movable arc contact and the coil of the disconnector in the prior art causes an arc; the purpose of the present invention is also to provide a The contact assembly of the isolating switch.

In order to achieve the above object, the technical solution of the contact assembly of the present invention is:

The contact assembly includes a main contact and an arc contact. The main contact is provided with an insulating support, and the arc contact is provided on the insulating support. Conductively connected to the main contacts.

The insulating support is fixed on the main contact through the conductive seat. The arc contact and the conductive seat are respectively connected to the two ends of the insulating support. The insulating support has a middle winding section for the arc extinguishing coil to be wound. The arc contact Both the head and the conductive seat have an end winding section for winding the arc extinguishing coil, and the outer diameter of the middle winding section is consistent with that of the end winding section.

The arc extinguishing coil is formed by winding a copper strip, and the ends of the copper strip are respectively fixed on the arc contact and the conductive seat by screws.

The insulating support is a cylindrical structure, and both ends of the insulating support are provided with external threads, and the conductive seat and the arc contact are connected with the insulating support through threads.

One end of the insulating support connected to the arcing contact is provided with an escape groove for avoiding the arcing contact, and the inner diameter of the insulating support is larger than the minimum radial dimension of the inner peripheral surface of the corresponding arcing contact.

The technical scheme of isolating switch of the present invention is:

The isolating switch includes a moving contact assembly and a static contact assembly. Both contact assemblies include main contacts and arc contacts, wherein at least one of the contact assemblies is provided with insulating supports on the main contacts, and the arc contacts are arranged on On the insulating support, the arcing contact is conductively connected with the main contact through an arc extinguishing coil wound around the outer periphery of the insulating support.

The insulating support is fixed on the main contact through the conductive seat. The arc contact and the conductive seat are respectively connected to the two ends of the insulating support. The insulating support has a middle winding section for the arc extinguishing coil to be wound. The arc contact Both the head and the conductive seat have an end winding section for winding the arc extinguishing coil, and the outer diameter of the middle winding section is consistent with that of the end winding section.

The arc extinguishing coil is formed by winding a copper strip, and the ends of the copper strip are respectively fixed on the arc contact and the conductive seat by screws.

The insulating support is a cylindrical structure, and both ends of the insulating support are provided with external threads, and the conductive seat and the arc contact are connected with the insulating support through threads.

One end of the insulating support connected to the arcing contact is provided with an escape groove for avoiding the arcing contact, and the inner diameter of the insulating support is larger than the minimum radial dimension of the inner peripheral surface of the corresponding arcing contact.

The beneficial effects of the present invention are:

Compared with the prior art, the contact assembly involved in the present invention is provided with an insulating support on the main contact, and an arc extinguishing coil is wound on the insulating support, and the arcing contact is connected with the main contact through the arc extinguishing coil. Conductive connection, thereby ensuring that the current can flow through the arc contact, coil, and main contact in sequence, ensuring the magnetic field strength in the coil, further improving the arc extinguishing effect, and minimizing the impact of arc contact shunting. Further, It is only necessary to arrange an arc contact with a small structure at the end of the arc extinguishing coil, and the cost is low.

Furthermore, the insulating support is fixed on the main contact through the conductive seat, and the compactness of the structure is ensured through the installation of the transitional conductive seat, and the fixing form of the coil is more selective, and the middle winding section and the end winding section The outer diameter is consistent to ensure the stability of the magnetic field of the arc extinguishing coil and to ensure effective electrical conduction.

Further, the arc extinguishing coil is made of copper strip, and the two ends are fixed on the conductive seat and the arc contact by screws, which effectively ensures the effective electrical contact between the coil and the arc contact and the conductive seat respectively.

Further, the insulating support is provided with an avoidance groove for avoiding the arcing contact, which ensures the installation space of the arcing contact on the insulating support, and the minimum inner peripheral surface size of the arcing contact is smaller than the inner diameter of the insulating support, ensuring that the arcing contact Avoidance of the corresponding arcing contact after the electrical contact.

Description of drawings

Fig. 1 is a schematic structural view of a specific embodiment of a contact assembly of the present invention;

Fig. 2 is a schematic diagram of the assembly structure of the moving contact assembly and the static contact assembly of Fig. 1;

Fig. 3 is a schematic diagram of the assembly structure of the contact assembly in Fig. 1 in the disconnector;

Fig. 4 is a C-C arrow view of Fig. 3 .

detailed description

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

The specific embodiment of the contact assembly of the present invention, as shown in Figures 1 to 2, the contact assembly is a moving contact assembly in a disconnector, which includes a moving main contact 1 whose axis extends left and right, and which is made of 6063 aluminum is processed and formed, and the outer surface is plated with silver to reduce the contact resistance coefficient, so as to ensure the effective electrical contact between the moving main contact 1 and the main conductive circuit. The moving main contact 1 is provided with a through hole extending along the axis. An inner flange is provided near the right end, and a copper contact seat 3 (i.e., a conductive seat) is connected to the inner flange through a screw 2. The copper contact seat 3 is a cylindrical structure, and one end has an outer flange. The seat 3 and the moving main contact 1 are fixed together by the screw 2 screwed on the outer flange and the inner flange. The inner wall of the hole of the copper contact seat 3 is provided with threads, and the contact also includes an insulating support cylinder 6 That is, the insulating support. The insulating support cylinder 6 includes threaded sections arranged at both ends and a middle winding section connecting the threaded sections. That is, the arc extinguishing coil, the coil 5 extends bidirectionally along the axial direction of the insulating support cylinder 6 to above the threaded section, and is arranged on the outer peripheral surface of the copper contact seat 3 and is fixedly connected by screws 4, and the end of the coil is wound around the copper contact seat The outer diameter of the winding section is consistent with the outer diameter of the middle winding section; the copper contact seat 3 is used as a transition base for installation, and its axis is consistent with the axis of the insulating support cylinder 6, and is screwed on the threaded section at the left end of the insulating support cylinder 6, and at the same time , The copper contact seat 3 is also used as a connection between the coil 5 and the electric circuit of the moving main contact 1 . The right end of the coil 5 is fixedly connected with a moving arc contact 7, the moving arc contact is made of ablation-resistant, high-hardness copper-tungsten alloy material, which is mainly used to strike the arc when the isolating switch opens and closes the busbar to convert the current, and avoids the arc Ablation of the moving main contact 1; there is no contact between the moving arc contact and the main contact 1, and the current conduction is completed through the coil 5 and the copper contact seat 3 connected to the coil 5, and the moving arc contact 7 is screwed on the The threaded section at the right end of the insulating support cylinder 6 and the two ends of the coil 5 are respectively fixed on the copper contact seat 3 and the moving arc contact 7 by bolts, which can ensure the effective electrical connection between the coil 5 and the copper contact seat 3 and the moving arc contact 7. touch. The insulating support is provided with an escape groove for avoiding the moving arc contact, and the minimum inner peripheral diameter of the moving arc contact is smaller than the inner diameter of the insulating support cylinder. Coil 5 is made of copper strip made of copper material, which can withstand high current within a certain range for a short time. Insulating heat-shrinkable tubes are used outside to ensure the inter-turn insulation of the copper coil 5, and there are no insulating heat-shrinkable tubes at both ends of the copper strip to ensure effective electrical contact between the coil 5 and the copper contact seat 3 and the moving arc contact 7. The insulating support cylinder 6 adopts a vacuum dipped rubber tube, which has certain insulation strength and high mechanical strength. The threaded section is coated with epoxy resin adhesive to avoid loosening after long-term movement, and the part outside the threaded section is covered with polyurethane layer to protect the vacuum dipping tube from the erosion of SF6 arc products.

When the moving contact is applied to the opening and closing process of the isolating switch, the static contact assembly 13 arranged on the right end of the moving contact assembly 12 as shown in Figure 2, the static contact assembly has an electrical connection with the moving main contact 1 The contact seat 10 is provided with a leaf spring contact finger 9 on the contact seat 10, which is used to electrically connect the moving main contact 1 of the isolating switch with the contact seat 10 when the isolating switch is closed. The static contact also includes The shielding cover 8 arranged on the contact seat 10 can shield the internal components on the static contact to ensure that the disconnector has a lower field strength value inside the contact seat 10, and a static arc contact 11 protrudes to the left. Cooperate with the moving arc contact 7 to start the arc.

When the busbar at the beginning of the isolating switch switches current, the moving main contact 1 of the isolating switch moves quickly to the left, so that the moving main contact 1 is disconnected from the leaf spring contact finger 9, but at this time the moving arc contact 7 of the isolating switch and the static The arc contact 11 still keeps in contact, and when the isolating switch continues to move to the left, the moving arc contact 7 is disconnected from the static arc contact 11. The distance between the contact 7 and the static arc contact 11, so the arc is only generated between the moving arc contact 7 and the static arc contact 11, and the arc current flows into the coil 5 through the moving arc contact 7, so that the coil 5 is energized Finally, a large axial magnetic field is generated, and the arc is rapidly rotated and elongated under the action of the magnetic field, and with the rapid cooling of SF6, the moving main contact 1 is moved to the left for a certain distance, and the arc contact passes through the zero point and then quickly extinguish, so that under the premise of not increasing the opening speed of the moving contact of the isolating switch, the coil 5 can completely obtain the arc current so that its own arc extinguishing performance can be kept at a relatively high level.

The structural diagram of the combined isolating and earthing switch shown in Figures 3 and 4, which includes the isolating switch transmission box 14, drives the moving contact assembly 12 of the isolating switch through the insulating pull rod 19 to open and close the isolating switch, and the guide support seat 15 passes through The contact fingers of the leaf spring are electrically connected with the moving contact assembly 12 of the isolating switch, the conductive rod 16 is installed on the guide support seat 15 through bolts, the conductive rod 16 is connected with the electrical connection 17 through the spring contact finger, and the electrical connection 17 is installed on the pot insulator 18, the other side of the pot insulator 18 is connected with the main conductive circuit.

In other embodiments, the contact assembly can be a static contact assembly, and can also be used on both the static contact assembly and the moving contact assembly.

In other embodiments, the conductive seat may not be provided, and a direct fixed connection between the main contact and the coil is sufficient.

In other embodiments, the coils may be fixed by bonding, riveting and other connection forms.

In other embodiments, the insulating support may not be arranged in the avoidance groove, and the arc contact is directly provided with an annular groove for the end of the insulating support to extend into, which can also ensure the installation space.

In other embodiments, the arc extinguishing coil can be replaced by ordinary copper wire or other types of coils, as long as it can be firmly fixed on the arc contact and the conductive seat.

The isolating switch involved in the present invention includes a moving contact assembly and a static contact assembly, wherein the specific embodiment of at least one contact assembly is consistent with the above-mentioned specific embodiment of the contact assembly, and will not be expanded in detail.

Claims (10)

1. The contact assembly, including the main contact and the arc contact, is characterized in that: the main contact is provided with an insulating support, the arc contact is arranged on the insulating support, and the arc contact is wound on the The quenching coil on the periphery of the insulating support is conductively connected to the main contacts. 2. The contact assembly according to claim 1, characterized in that: the insulating support is fixed on the main contact through a conductive seat, the arc contact and the conductive seat are respectively connected to both ends of the insulating support, and the insulating support There is a middle winding section for the arc extinguishing coil, the arc contact and the conductive seat have end winding sections for the arc extinguishing coil, the middle winding section and the end winding Set the outer diameter of the segments to be the same. 3. The contact assembly according to claim 2, wherein the arc extinguishing coil is formed by winding a copper strip, and the ends of the copper strip are respectively fixed on the arc contact and the conductive seat by screws. 4 . The contact assembly according to claim 2 , wherein the insulating support is a cylindrical structure, and both ends of the insulating support are provided with external threads, and the conductive seat and the arc contact are connected to the insulating support through threads. 5. The contact assembly according to claim 4, characterized in that: one end of the insulating support connected to the arc contact is provided with an escape groove for avoiding the arc contact, and the inner diameter of the insulating support is larger than the corresponding arc contact. The minimum radial dimension of the inner peripheral surface of the contact. 6. An isolating switch, comprising a moving contact assembly and a static contact assembly, both contact assemblies including main contacts and arc contacts, characterized in that: at least one of the main contacts of the contact assembly is provided with The insulating support, the arcing contact is arranged on the insulating support, and the arcing contact is conductively connected with the main contact through the arc extinguishing coil wound around the insulating support. 7. The isolating switch according to claim 6, characterized in that: the insulating support is fixed on the main contact through a conductive seat, the arc contact and the conductive seat are respectively connected to the two ends of the insulating support, and the insulating support is There is a middle winding section for winding the arc extinguishing coil, the arc contact and the conductive seat both have end winding sections for the arc extinguishing coil winding, the middle winding section is connected with the end winding The segments have the same outer diameter. 8. The isolating switch according to claim 7, wherein the arc extinguishing coil is formed by winding a copper strip, and the ends of the copper strip are respectively fixed on the arc contact and the conductive seat by screws. 9 . The isolating switch according to claim 7 , wherein the insulating support is a cylindrical structure, and both ends of the insulating support are provided with external threads, and the conductive seat and the arc contact are connected to the insulating support through threads. 10. The isolating switch according to claim 9, characterized in that: one end of the insulating support connected to the arcing contact is provided with an escape groove for avoiding the arcing contact, and the inner diameter of the insulating support is larger than the corresponding arcing contact The smallest radial dimension of the inner peripheral surface of the head.