CN1008415B

CN1008415B - Gas-blast switch

Info

Publication number: CN1008415B
Application number: CN 85107324
Authority: CN
Inventors: 格哈特·莫思
Original assignee: BBC Brown Boveri AG Switzerland
Current assignee: BBC Brown Boveri AG Switzerland
Priority date: 1985-09-30
Filing date: 1985-09-30
Publication date: 1990-06-13
Also published as: CN85107324A

Abstract

The present invention relates to an air-blast switch for high voltage, which is provided with two coaxial electric arc contacts, a heating chamber and a compression chamber, wherein the two coaxial electric arc contacts move correspondingly, and the heating chamber and the compression chamber are coaxial. The arc extinguishing air in the compression chamber is compressed by a sliding part. When small current is switched off, low arc extinguishing air pressure is generated in the heating chamber. When the air pressure in the compression chamber is high enough, some arc extinguishing air enters the heating chamber through a check valve for reinforcing to blow the arc pulled out between the two electric arc contacts. Because an electric arc contact of a movable contact part has an exhaust pipe, the free end of a fixed contact part facing to the exhaust pipe extends into an expansion chamber in the axial direction. A device used for controlling the pressure and charging the arc extinguishing air for the compression chamber is arranged between the compression chamber and the expansion chamber. Thus, the breaking capacity of the present invention is increased, and the actuating energy of the present invention is reduced.

Description

Gas-blast switch

The present invention is related to gas-blast switch.

This gas-blast switch is from U.S.'s comment file (Auslegeschrift) 4,139, and 732 know.In this switch, when switch disconnected, heating and the blow-out gas storage that compressed were in heating chamber.When switch do to disconnect action, by the blow-out gas that produces compression in addition again that moves of the compression piston of discharge chambe, discharge chambe was received heating chamber through check-valves.Might use lower driving energy blow-out in this way, though in heating chamber by the blow-out gas pressure that adds hot compression when very low.When disconnecting big short circuit current, make closure of check ring under the high pressure effect of the compression blow-out gas of in heating chamber, preserving, and stop the slip of the compression piston of discharge chambe.

From european patent application, 0,035, also know a kind of gas-blast switch in 581, the required blow gas pressure of blow-out is to be produced by the electric arc of arc chamber itself, and it enters the reservoir pressure chamber through check-valves, and is stored to blow at this place always and begins.In addition, a compression piston is housed also, it can further compress blow-out gas through certain time-delay, this gas enters the reservoir pressure chamber through check-valves, and from here, air-flow enters arc chamber together with the Compressed Gas that is produced by electric arc itself through next check-valves, enter expanding chamber from air-flow here, simultaneously arc blow-out.

Under the situation that little electric current disconnects, because the blow gas pressure that electric arc produces is low, it is enough with the arc chamber storage, does not open to the check-valves of reservoir pressure chamber from arc chamber.The compression blow-out gas that is produced by compression piston has nothing to do with the size of turn-off current, and this gas enters arc chamber through following two check-valves (in other two back) as previously mentioned, and from arc blow-out here.

Disconnect under the very large current conditions, the air pressure that is produced by electric arc is quite big, to making all gassies of arc chamber and reservoir pressure chamber.So originally the compression blow-out gas that is produced by compression piston can not lead to into reservoir pressure chamber, because its air pressure is lower.When compression stroke, because gas can not be discharged to the reservoir pressure chamber, the pressure under the discharge chambe compression piston further increases.For fear of the switch drive overload, there is another adjustable check-valves to be contained on the compression locular wall, if the pressure of compression is too big, discharge chambe directly is vented to expanding chamber.So many check-valves are installed, and some may touch the residue of hot gas and switch transition generation in them, this should be considered as weakness, because in these the local caused spring defectives of corrosion that can not get rid of seal receptacles.

The objective of the invention is to create a class gas-blast switch of mentioning when a kind of this paper begins, but its interrupting capacity is increased, drive energy simultaneously and reduce.

Be characterized as according to gas-blast switch of the present invention institute tool: do not use under the additional active component condition when driving a certain maximum of design code not exceeding, can be reliably and limit selectively or reduce compression pressure; It shows the possibility that has effective especially dual blow-out simultaneously.Also finding in addition has this advantage, and the power of compression guiding valve is controlled in whole switch disconnection process, so avoid producing unallowed stress.

Hereinafter, by the embodiment of description of drawings main points of the present invention, wherein:

Fig. 1 represents the embodiment according to gas-blast switch of the present invention.

Fig. 2 represents another modification according to the gas-blast switch proposition of Fig. 1.

The axial cross section of in Fig. 1 and Fig. 2, representing gas-blast switch constructed in accordance, in each figure, center line right-hand side with the dot-dash line drawing is represented switch off state, the switch connection state is represented in the left side of line, in these figure with same parts or there are the parts of same function to be marked with identical symbol.

The gas-blast switch of Fig. 1 has a cylindrical cover 1 according to the present invention, and it is made up of the suitable insulation material.Its top embeds metal adpting flange 2, and is airtight.The gas-blast switch bottom also is airtight with cylindrical metal shell 3 sealings, not completely shown in the drawings metal-back 3.Hollow cylinder 5 of end wall 4 upper supports of metal-back 3.At the center of end wall 4, have the perforation of piston ring.This hole and hollow cylinder 5 are used as the guider that compresses sliding part 6, and the actuator of switch can make the compression sliding part move up and down not shown actuator vertically.

Compression sliding part 6 is made up of hollow cylinder axle 7 and compression piston 9, in the hollow shaft upper end, the hollow arc contact 8 that is connecting movable contact member 8a, compression piston 9 has cylindrical extension, this part is as the rated current contact 9a of contact members 8a, top in the extension, insulation nozzle 10 is screwed into this place.Insulation nozzle 10, compression piston 9 and rated current contact 9a constitute the cover 10a of expulsion element, surround heating chamber 11, and the enclosing electric arc contact 8 coaxially.End 4, hollow cylinder 5, axle 7 and compression piston 9 surround discharge chambe 12, and discharge chambe 12 can be air-breathing from expanding chamber 13 through the check-valves 12a in being contained in end wall 4, and discharge chambe 12 can be through the check-valves in being contained in compression piston 9 14 to heating chamber 11 exhausts.If the pressure in the discharge chambe 12 surpasses a certain value, pressure override valve 30 works, and makes the pressure that surpasses be discharged to expanding chamber 13.In addition, several grooves 15,16 are arranged in axle 7, these grooves can make discharge chambe 12 to expanding chamber 13 exhausts at short notice.These grooves extend vertically, and the depth ratio width of ditch is big, make that the mechanical wear of the piston ring that slides on them is little.They can also have different length, and can be configured in the inwall of hollow cylinder 5 at least partially.

At the switch connection state, they are radially defining expulsion element cover 10a arc contact 8 and rated current contact 9a() embed solid arc contact 17 and the hollow rated current contact 18 of contact members 17a, contact members 17a and adpting flange 2 are electrically connected.The rated current of gas-blast switch from adpting flange 2 through rated

current contact

18 and 9a to compression piston 9, again through the contactor lead-in wire (not shown) of axle 7 to another adpting flange.

Hereinafter, explain the course of work of the present invention in more detail, see Fig. 1:

In the switch connection position (left-hand side of Fig. 1), discharge chambe 12 links to each other with expanding chamber 13 through groove 15, and two indoor blow-out gas pressures can reach equal by groove 15.Another way is, the check-valves 12a by hollow cylinder 5 bottoms also can make pressure equate.At the switch open position, the actuator of switch acts on the compression sliding part 6, and transmit downward acceleration, when rated current contact 9a separates with rated current contact 18, the rated current loop disconnects, electric current inwardly commutates on the power current arc contact 8,17, this electric current from adpting flange 2 through arc contact 17 and 8 to axle 7.

Then, arc contact 8 and opening in 17 minutes, and form the electric arc (not shown) 8,17 of two contacts.Electric arc warms up the blow-out gas in the heating chamber 11, makes it form high pressure, and a part of ionization simultaneously and contaminated gas are discharged through blast pipe 32 from arc region, and this pipe is positioned at hollow arc contact 8 and hollow shaft 7.

If arc current is little, arc energy may be not enough to fully increase the gas pressure in the heating chamber 11.For this reason, be provided with an additional compression device that has nothing to do with electric arc, in order to produce the blow-out gas of high pressure.Its measure is: a suitable length of selected blast pipe 32, and make electric arc in the starting stage that forms, only have a spot ofly to add overheated blow-out gas and can spill, pipe 32 is between the hole 33 on the free end of fixed contact member 17 and spools 7 of arc contact 8.On axle 7, blast pipe 32 33 leads to expanding chamber 13 through the hole.

In the discharge chambe 12 of additional compression set, when compression sliding part 6 is made compression stroke, just produce gases at high pressure.When switch disconnected the action beginning, short groove 15 can make some blow-out gases spill from discharge chambe 12, form high pressure like this after certain time-delay, and when the needs arc blow-out, high pressure blow-out gas is just available.Can select the length of suitable discharge pipe 32 like this, make in heating process, promptly use the blow-out gas of more weak arc current heating can reach heating chamber 11, it can not be discharged to expanding chamber through discharge pipe 32 fully.

The appropriate length of selected discharge pipe 32 may be between c/32f and c/3f, and wherein c is the velocity of sound of blow-out gas under the inflated condition, and f is the supply frequency of the electric current of switch disconnection.Verified, when striking current hour, Xuan Ding size makes blow-out gas be difficult to flow to expanding chamber 13 from arc region like this.This may be because under the situation of selected blast pipe 32 length, the cold blow-out gas that is positioned at blast pipe 32 stops the heating blow-out gas that is positioned at arc region to flow out, and impels the blow-out gas of heating to flow to heating chamber 11 in this way.Because at the arc heating state, in arc region blow-out gas, the compressional wave of propagating with velocity of sound c forms, this ripple is along discharge pipe 32 conduction, under blast pipe 32 is of convenient length situation, this ripple is sentenced the dilatational wave reflection at its stomidium (towards expanding chamber 13), and like this, the dilatational wave of reflection turns back to arc region when current over-zero.

If the pressure of the blow-out gas in heating chamber 11 still is not enough to put out electric arc, the high pressure blow-out gas that produces in discharge chambe 12 enters heating chamber 11 along very short path through check-valves 14.When electric current during near zero passage, as long as fixing arc contact 17 has left the hole 34 among the blow-out locular wall 10a, the high pressure blow-out gas in heating chamber 11 just enters the blow-out district, produces dual and effective especially arc blow-out.

In the actual compression process, groove is hiding, and is inoperative therefore.Yet in the compression process relevant with actuation characteristic, maximum pressure may occur.By adopt pressure override valve 30 and (or) make groove 16 more close grooves 15 just can control these maximums, and be unlikely the increase actuating force.Reached open position not long ago at switch, in the stroke district, electric arc extinguishes, and also no longer needs arc blow-out, and remaining compression pressure is discharged to expanding chamber 13 through groove 16.Adopt the result of this method, required actuation of the switch energy and also have actuator itself all especially little.

If must block very big turn-off current, very high air pressure just occurs in heating chamber 11, and during to blow-out, the gas that oneself is housed in heating chamber by it is enough to blow-out.In this case, check-valves 14 needn't be opened.Avoid the obstruction of undersized actuator, but, all Compressed Gas can both from discharge chambe 12 through groove 16 and (or) pressure override valve 30 enters the expanding chamber 13.

Fig. 2 represents to have changed compression piston 9 here according to the embodiment of the gas-blast switch of Fig. 1 derivation, and compression saddle 6 contains the compression piston of being with sleeve 20, has replaced end wall 4 with fixed piston 19, and piston 19 is received on the metal-back 3 rigidly.Compression saddle 6 slides above piston 19 airtightly, and this saddle surrounds discharge chambe 12 with piston.In piston 19, the check-valves 12a to discharge chambe 12 inflations is installed, when switch connection, this valve allows discharge chambe 12 to bleed from expanding chamber 13.The arc contact 17 of fixed contact member 17a is hollow-core constructions, like this, at the electric arc root of arc contact by arc blow-out consumingly.

Be furnished with this advantage among Fig. 2, embed two effect of dust that translational surface is not fallen from above by switch motion of the piston ring of piston 19.The translational surface of inner carrier ring is well protected, because the compressed gas physical efficiency that flows to gap 21 through groove 15 and 16 further decontaminates.If the part of groove 15 and 16 moves on to the inwall of the compression piston of band sleeve 20, the translational surface of outer piston ring can be protected with similar advantageous manner.

The component names table

1 insulating boot

2 adpting flanges

3 metal shells

4 end walls

5 hollow cylinders

6 compression sliding parts

7

8 arc contacts

The 8a contact members

9 compression pistons

9a rated current contact

10 insulation nozzles

10a expulsion element cover

11 heating chambers

12 discharge chambes

The 12a check-valves

13 expanding chambers

14 check-valves

15,16 grooves

17 arc contacts

The 17a contact members

18 rated current contacts

19 pistons

The compression piston of 20 band sleeves

21 gaps

30 pressure override valves

32 blast pipes

33 holes

34 holes

Claims

1, gas-blast switch is by forming with the lower part

-be filled with the cover (1) of blow-out gas,

-by the expanding chamber (13) that covers (1) encirclement,

-two contact members (8a, 17a), it is positioned at cover (1), and can be engaged with each other vertically or throw off, and each contact members is made up of arc contact (8,17) and rated current contact (9a, 18),

-one expulsion element's cover (10a), it centers on the arc contact (8) of the movable contact (8a) of two contact members (8a, 17a) coaxially, and receives this movable contact rigidly,

-one hole (34), it passes expulsion element's cover (10a), and at the switch connection state, the arc contact (17) of the fixed contact member (17a) of two contact members (8a, 17a) passes this hole.

-one heating chamber (11), it is in expulsion element's cover (10a), and be arranged coaxial with respect to the arc contact (8) of movable contact member (8a), when switch disconnected action, it was in order to hold the blow-out gas by the heating of the switching arc in expulsion element's cover (10a).

-one compression sliding part (6), it is installed in expulsion element's cover (10a) and locates, and when switch disconnects action, produces the blow-out gas of compression by this sliding part in discharge chambe (12), and discharge chambe (12) is a coaxial arrangement with respect to movable contact member (8a), and

-one check-valves (14), it is contained on the compression sliding part (6), and in heating chamber (11),

It is characterized by:

The arc contact (8) of-movable contact member (8a) has a blast pipe (32), extends axially from its free end in the face of fixed contact member (17a), and one through to expanding chamber (13),

-between discharge chambe (12) and expanding chamber (13), be equipped with one and be used for controlled pressure and give the device that fills blow-out gas in the discharge chambe (12) again.

2, the gas-blast switch according to claim 1 is characterized as:

-should have such size at the free end of the arc contact (8) of movable contact member (8a) and the length that enters the blast pipe (32) between the hole of blast pipe (32) of expanding chamber (13), make when switch disconnects, in blast pipe, to form standing wave.

3, the gas-blast switch according to claim 2 is characterized as:

The length of-blast pipe (32) is greater than c/32f and less than c/3f, and wherein c is the velocity of sound of blow-out gas, and f is the supply frequency that is cut off electric current.

4, be characterized as according to claim 1,2 or 3 gas-blast switch:

-a kind of device of being used for controlled pressure and filling blow-out gas for discharge chambe (12) has a pressure override valve (30) and another check-valves (12a), (or) at least two grooves (15,16), they extend vertically, when the switch connection position, groove (15) is connected discharge chambe (12) and expanding chamber (13)

When the switch open position, groove (16) is connected discharge chambe (12) and expanding chamber (13).

5, the gas-blast switch according to claim 4 is characterized as:

-the groove (15,16) that provided is on the axle (7) at least partially, and this axle is at the center of compressing sliding part (6).

6, the gas-blast switch according to claim 4 is characterized as:

-the groove (15,16) that provides is in the inwall of hollow cylinder (5) at least in part, and this cylinder constitutes the shell of discharge chambe (12).

7, the gas-blast switch according to claim 4 is characterized as:

The degree of depth of-groove (15,16) is greater than width, and different length is arranged.

8, be characterized as according to the gas-blast switch one of in the claim 1 to 7:

-fixing contact members (17a) has a hollow rated current contact (18), it centers on its arc contact (17) at a certain distance, when the switch connection position, it engages with the rated current contact (9a) of movable contact member (8a), and contact (9a) is contained on expulsion element's cover (10a).