CN85103335B - Earthed switch of the switch device of gas isolation - Google Patents

Abstract

The present invention relates to an earthed switch which is used for insulating switch equipment of gas, wherein a conductor which is arranged in a container is provided with a static contact; in addition, the present invention is provided with a movable contact, the movable contact can be moved by operating an operating mechanism which is arranged in an operating box, and thus, the movable contact and the static contact can be switched on or switched off. The operating box is arranged in a branch pipe of the container, and an insulating plate is arranged between the branch pipe and the container. In order to enable the movable contact and the container to form conductive connection, more than one ground rod is adopted; in addition, when the ground rods are connected, the electromagnetic direction which generates between the movable contact and each ground rod is considered, the method of connecting more than one ground rod is adopted, and then, the electromagnetic force which acts on the movable contact can be largely reduced.

Description

The earthed switch of gas-insulated switchgear

This patent relates to a kind of earthed switch of a gas-insulated switchgear.

Gas-insulated switchgear generally all is equipped with an earthed switch, so that will be installed in the energized conductor ground connection in the container, and the personal safety when guaranteeing maintenance and checking each parts.

Shown in Figure 1 is the universal architecture of earthed switch

Conductor 10 in container 1 adopts the mode of insulation to install, and uses a lead ground connection usually.A ring flange is arranged on the arm 2 of container 1, and a control box 4 just is installed on this ring flange with bolt or other similar devices.So that dismounting, and an insulation board 3 is housed between them, in control box 4, be equipped with and can move and a current-collector 8 from 6, one movable contacts of 5, one connecting rods of a connecting rod of peripheral operation.Control box 4 is connected on the container by an earth rod 9, and ground connection thus.Dismantle after the earth rod 9, case 4 and moving contact 7 just disconnect on electric with container 1.Therefore, earthed switch can be used as the terminal of a test for ground switch in the test of test insulation resistance etc.

When the operational grounding switch, from outside rotation connecting rod 5, conduct to moving contact 7 by connecting rod 6, make moving contact 7 touch fixed contact 11.Fixed contact 11 is located on the conductor 10, in order to conductor 10 ground connection.

When earthed switch was connected under the charged situation of conductor 10, electric current promptly flowed to the earth by fixed contact 11, moving contact 7, current-collector 8, control box 4, earth rod 9 and container 1 from conductor.

Be in this case circuit as shown in Figure 2.

Because the result of circuit circulation just has electromagnetic force to act on the moving contact 7, that is electromagnetic force f1 and f ₂Act on simultaneously on the moving contact 7.f ₁Be because the electromagnetic force that the mutual inductance magnetic field effect of conductor 10 produces; f ₂Be because electric current flows through moving contact 7 and flows through the electromagnetic force that earth rod 9 is produced.Two kinds of electromagnetic forces that act on the moving contact 7 make the moving contact bending, so that depart from the axis direction of moving contact 7.When connecting earthed switch,, contact 7 and 11 can not be fitted like a glove owing to produce above-mentioned off-set phenomenon.Its result is that contact is subjected to the influence of contact force between the two and impaired greatly.

If with moving contact 7 thickenings, so as to the flecition of opposing electromagnetic force, operating system is increased in size therefrom.Particularly for the electric power system that gas-insulated switchgear is housed, its capacity constantly increases, the electric current that earthed switch is produced when connecting also constantly increases, thereby require contact that is enough to resist bigger electromagnetic force of design, the result makes the size of earthed switch strengthen Japanese Utility Model No.52-54761(1977) and Japanese utility model application bulletin M ₀.57-27817(1977) content is exactly the example of above-mentioned earthed switch.In addition, as US Patent No 3,778,574 and Japan special permission application bulletin No.58-5726(1983) and the content of corresponding U.S. Patent No. 4,486,634 promptly be to utilize earthed switch to make the example of test for ground switch.

The objective of the invention is to reduce the earthed switch electromagnetic force influence that makes the contact bending, that use on the gas-insulated switchgear in order to provide a kind of.

Another object of the present invention is can be reduced in the earthed switch electromagnetic repulsion force influence that produces between conductor and the moving contact, that use on the gas-insulated switchgear greatly in order to provide a kind of.

An earthed switch that gas-insulated switchgear is used among the present invention includes and be located at fixed contact and another moving contact that can operate by operating mechanism, can be switched on or switched off with fixed contact on the conductor in a container.Operating mechanism is located in the control box, and this case is contained on the arm on the container.An insulation board is housed between case and the arm, also has one to be exclusively used in the earth rod of making conduction connection usefulness between moving contact and the container in addition: particularly to adopt more than one earth rod; And the relative position between earth rod and the moving contact should make the electromagnetic force that produces on the moving contact and the electromagnetic force on the earth rod cancel each other out.Owing to adopted above-mentioned arrangement, moving contact and operating mechanism just needn't strengthen, thereby have reduced the volume of the earthed switch that gas-insulated switchgear uses.

Fig. 1 is the profile of general earthed switch;

Fig. 2 is the circuit diagram of the earthed switch among Fig. 1;

Fig. 3 and Fig. 4 are the front view and the part side cutaway views of an earthed switch, an example of the present invention;

Fig. 5 is the circuit diagram of the earthed switch among Fig. 3;

Fig. 6 and Fig. 7 are the profiles of facing and overlook part of the earthed switch in another example of the present invention;

Fig. 8 and Fig. 9 are the circuit diagrams of earthed switch among Fig. 6 and Fig. 7;

Now above example is respectively described below with reference to drawing:

Fig. 3 is the different of earth rod with earthed switch shown in Fig. 4 and common earthed switch difference, below will be illustrated at this point.

Adopted two earth rod 9a and 9b to come attended operation case 4 and container 1.Two earth rod 9a and 9b and moving contact 7 are all established at grade, and vertical with leading body 10.Two earth rods are actually the both sides that are arranged in moving contact 7 symmetrically.The lower end of earth rod 9a and 9b is connected on the both sides of container 1 respectively.The joint of these two lower ends in fact also with conductor 10 at grade.

More particularly, the end of earth rod 9a and 9b removably is connected on the ring flange, that is to say, is to utilize bolt 13,13 to be connected on the ring flange 4a of control box 4; The other end then is to be connected on boss 12a and the 12b with dismountable bolt 14.Boss is arranged in the both sides of container 1, toward each other.All the other structures are identical with common earthed switch, repeat no more.

Shown in Figure 5 is schematic diagram when earthed switch is connected.

Because earth rod 9a and 9b are the both sides that are located at moving contact 7 symmetrically, act on the electromagnetic repulsion force f on the moving contact 7 ₂And f ' ₂Direction shown in the arrow among the figure.Therefore, f ₂With f ' ₂Two power cancel each other out.Consequently, because the bending force that electromagnetic force produced is very little to the influence that moving contact 7 causes, so moving contact can be done it thinly.

In this example, earth rod 9a and 9b following terminates on the both sides boss joint 12a and 12b of container 1.Be actually with fixed contact 11 and be in line.But the three might not be in line, and is about to see in next example.If electromagnetic repulsion force f ₂And f ' ₂Compare with the electromagnetic repulsion force between conductor 10 and the moving contact 7, when the former arrived to a certain degree greatly, the latter just can ignore.This is because moving contact 7 has been subjected to the former effect, maintains static.If f ₁Very little, just do not need above-mentioned effect, earth rod 9a and 9b just can be connected on any position of container 7.When earthed switch had the very long moving contact of an arm 2 and axis, earth rod 9a and 9b just can be connected on any position of container.Be located at the place ahead or the rear of the axis of conductor 10, do not arrange in a line, be fine with moving contact 7, but, when actual earthed switch is set, consider how to make to act on the total electromagnetic force equilibrium on the moving contact 7 and do not produce bending force, in other words, electromagnetic force is cancelled each other.Even if earth rod 9a and 9b slightly upwards or are down moved, also can obtain same effect.

At Fig. 6 and earthed switch shown in Figure 7, be the measure of taking at the electromagnetic repulsion force of conductor 10 and moving contact 7.When the arm on the container 12 is when upwards installing in the footpath of container, be particularly suitable for adopting this arrangement.

The example of Fig. 6 and Fig. 7 also is that earth rod 9a and 9b are located on the plane perpendicular to the axis of conductor 10; This point is identical with the example of Fig. 3 and Fig. 4.But moving contact 7 earth rod 9a among Fig. 6 and Fig. 7 and 9b are not at grade, this be both differences in other words, earth rod 9a and 9b are located at distance perpendicular to conductor 10 with comprise that there is certain distance on the plane of moving contact 7, and are positioned at a relative side of power input; As shown in Figure 6, be the right side.In this case, earth rod 9a and 9b detachably are being contained on boss 12a and the 12b, and the lower end of earth rod also can slightly move up or down.The optimum position of earth rod 9a and 9b lower end is to come on the straight line with fixed contact.

Fig. 8 and shown in Figure 9 be the circuit of this earthed switch.

On moving contact, there are three electromagnetic repulsion forces to interact, i.e. f ₁, f ₂And f ' ₂; f ₁In moving contact and 10 generations of conductor; f ₂Between moving contact 7 and earth rod 9a; F ' ₂Then be between moving contact 7 and the earth rod 9b.Electromagnetic repulsion force f ₂And f ' ₂In each can be decomposed into two component.A component is perpendicular to conductor 10; Another component is parallel to conductor 10.f ₂And f ' ₂Vertical component cancel each other; f ₂And f ' ₂Parallel to component then with electromagnetic repulsion force f ₁Offset.The result can be fully moves moving contact 7 along the direction of its axis, so that the diameter of moving contact can be done it thinly.f ₂And f ' ₂Parallel between component is along with earth rod 9a and 9b and moving contact 7 in the variation of the distance of lead 10 directions and change.Preferably according to calculating or choosing these data through overtesting.

In this example, all be to describe with single-phase earthed switch.These explanations also are applicable to the three-phase earthed switch that is located in the common container certainly, are applicable to that also the conductor in the container is the earthed switch of three-phase, and other common earthed switches of various structures.

The earthed switch used of the gas-insulated switchgear of indication, the both sides that earth rod is located at moving contact respectively in the present invention.The electromagnetic repulsion force that is produced between moving contact and this two earth rods has at least a part to cancel each other.The result can reduce the curved electromagnetic force that causes that acts on the moving contact, thereby makes moving contact and operating mechanism etc. can do smallerly, and then earthed switch also can be done smallerly, and this is very favourable.

Claims (5)

1, earthed switch that gas-insulated switchgear is used comprises: a gas isolated container; Be located at a leading body in this container; Be located at a fixed contact on this leading body; A control box is equipped with a moving contact in the case, this moving contact is movable to this fixed contact and is switched on or switched off; And operating mechanism as this moving contact of operation; Described control box is contained on this container, an insulation board is housed between case and container, in outside dismountable grounded parts is housed near this container at described moving contact place, be used between described moving contact and this container, realizing selectively being electrically connected by the aforesaid operations case, it is characterized by, described grounded parts is divided into substantial symmetry two parts in described moving contact, and every part is being connected between operating mechanism and the said vesse on the plane perpendicular to described leading body.

2, according to the described earthed switch of claim 1, it is characterized by, described two parts are connected on the relative both sides of described container outer surface respectively.

3, according to the described earthed switch of claim 2, it is characterized by, described moving contact can move along the installing plane of earth rod.

4, according to the described earthed switch of claim 2, it is characterized by, described plane perpendicular to this leading body is the axle certain distance part of axially leaving described moving contact that is in along this leading body, makes the electric current that flows through this leading body and grounded parts cause the repulsion that is added between described moving contact and the grounded parts to cancel out each other.

5, according to the described earthed switch of claim 1, it is characterized in that, on the outer surface of these container both sides, be respectively equipped with two connection boss, each is in a side of this leading body, described two earth rods end separately, be connected respectively to described connection boss removably, two earth rods other end separately is connected respectively on the flange of described control box respective side removably.

Images