CA1038428A - Puffer interrupter with down stream initiated arc - Google Patents
Puffer interrupter with down stream initiated arcInfo
- Publication number
- CA1038428A CA1038428A CA216,189A CA216189A CA1038428A CA 1038428 A CA1038428 A CA 1038428A CA 216189 A CA216189 A CA 216189A CA 1038428 A CA1038428 A CA 1038428A
- Authority
- CA
- Canada
- Prior art keywords
- nozzle
- contact
- movable
- movable contact
- stationary
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
- H01H33/70—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid
- H01H33/88—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid the flow of arc-extinguishing fluid being produced or increased by movement of pistons or other pressure-producing parts
- H01H33/90—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid the flow of arc-extinguishing fluid being produced or increased by movement of pistons or other pressure-producing parts this movement being effected by or in conjunction with the contact-operating mechanism
- H01H33/91—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid the flow of arc-extinguishing fluid being produced or increased by movement of pistons or other pressure-producing parts this movement being effected by or in conjunction with the contact-operating mechanism the arc-extinguishing fluid being air or gas
Abstract
PUFFER INTERRUPTER WITH DOWNSTREAM INITIATED ARC
ABSTRACT OF THE DISCLOSURE
The movable contact of a puffer type interrupter is movably connected to the nozzle of the puffer breaker so that, when the contacts of the puffer braker separate, the arc is initiated downstream of the nozzle throat and thereafter the nozzle and contact move relative to one another to place the contact upstream of the nozzle throat and to a position which maximizes the interruption operation of the breaker.
ABSTRACT OF THE DISCLOSURE
The movable contact of a puffer type interrupter is movably connected to the nozzle of the puffer breaker so that, when the contacts of the puffer braker separate, the arc is initiated downstream of the nozzle throat and thereafter the nozzle and contact move relative to one another to place the contact upstream of the nozzle throat and to a position which maximizes the interruption operation of the breaker.
Description
; :
~.03842B :::
BACKGROUND OF THE INVENTION
This invention relates to puffer type circuit interrupters, and more specifically relates to a novel arrange- -ment whereby the movable contact of a puffer type interrupter is flexibly connected to a gas directing nozzle so that the arc between the separating interrupter contacts is initially drawn downstream of the nozzle, with the movable contact later returning to its preferred upstream position within the nozzle ;
after the initial arcing operation.
Single pressure SF6 type puffer interrupters are well known in the art and commonly comprise a pair of separable contacts which are contained within a sealed container filled with sulfur hexzfLuoride gasor the like. One of the contacts is normally fixed to a nozzle-shaped member which encloses ; the area of engagement between the two cooperating contacts.
The movable contact is connected to a piston and cylinder arrangement such that, when the movable contact moves to -a disengaged position, the piston and cylinder force gas flow through the nozzle and through the region at which the contacts se~arate. This then provides a temporarily high-pressure region which moves gas through the arcing region to assist in the extinction of the arc drawn between the separating contacts and to sweep the space between the separating contacts clear of ionized products.
~`''` ~
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In order to obtain interruption in this type breaker, two conditions must be satisfied:
(1) The opening stroke of the movable contact must be sufficient to establish an open gap large enough to with-- stand the crest of the system recovery voltage; and
~.03842B :::
BACKGROUND OF THE INVENTION
This invention relates to puffer type circuit interrupters, and more specifically relates to a novel arrange- -ment whereby the movable contact of a puffer type interrupter is flexibly connected to a gas directing nozzle so that the arc between the separating interrupter contacts is initially drawn downstream of the nozzle, with the movable contact later returning to its preferred upstream position within the nozzle ;
after the initial arcing operation.
Single pressure SF6 type puffer interrupters are well known in the art and commonly comprise a pair of separable contacts which are contained within a sealed container filled with sulfur hexzfLuoride gasor the like. One of the contacts is normally fixed to a nozzle-shaped member which encloses ; the area of engagement between the two cooperating contacts.
The movable contact is connected to a piston and cylinder arrangement such that, when the movable contact moves to -a disengaged position, the piston and cylinder force gas flow through the nozzle and through the region at which the contacts se~arate. This then provides a temporarily high-pressure region which moves gas through the arcing region to assist in the extinction of the arc drawn between the separating contacts and to sweep the space between the separating contacts clear of ionized products.
~`''` ~
"`
In order to obtain interruption in this type breaker, two conditions must be satisfied:
(1) The opening stroke of the movable contact must be sufficient to establish an open gap large enough to with-- stand the crest of the system recovery voltage; and
(2) The opening stroke must develop a sufficient pressure differential across the nozzle to provide effective sweeping and deionization of the arc spa~e.
During the opening stroke of the movable contact, it is also desirable to keep the energy released in the arc space to a minimum and to release this energy in such --a manner as to minimize its effect on the interior components and to minimize the forces necessary to operate the interrupter.
In puffer interrupters of this type, it is common practice to fix a movable contact to the nozzle so that both move relative to a stationary contact, and further to fix the end of the movable contact at some fixed and preferred location which is upstream of the interrupter nozzle throat. The arc which is drawn between the separating contacts in such a device is then initiated upstream of the nozzle and will be drawn through the nozzle throat during the first part of the opening stroke.
During the opening stroke and as pointed out above, the arc produces various types of arcing products and ionized gas in the region which is upstream of the nozzle so that these products and ionized gases must be swept free if inter-ruption is to be obtained. Moreover, the arc and heated gases produced by the arc are immediately adjacent to the no~zle and the nozzle throat, thereby causing thermal deterioration of the nozzle which can reduce the interrupting lifetime of the device.
A further disadvantage of the fixed positioning of the movable contact upstream of the nozzle throat is that the ,- ,, , ~ : ~ . . .
initial arc which is drawn will cause a high-pressure zone in the nozzle :~-throat which results in a back pressure which must be overcome by higher operating forces from the operating mechanism. Note further that the back pressure in the nozzle can result momentarily in a back flow of gas so that arc products could be brought into the puffer piston area.
In accordance with the invention, the movable contact and the movable nozzle are movably connected to one another and the movable contact is normally biased to a preferred location slightly upstream of the nozzle -throat. However, upon operation of the interrupter, the movable contact and nozzle move relative to one another so that the end of the movable contact is downstream of the nozzle throat at the time an arc is initiated -between the separating contacts. Following the initial arcing interval, ;~ -the movable contact returns to its preferred upstream location relative to the nozzle, when a sufficiently large open gap is formed to withstand the crest of the system recovery voltage and enough pressure has developed ;
to produce effective arc sweeping action.
Therefore, according to this invention, a puffer type circuit ; interrupter comprises a stationary elongated contact and a movable contact movable between an engaged and disengaged position with said stationary contact. An insulation nozzle surrounds said movable and stationary - contacts and an operating rod is connected to said movable contact, means being provided for flexibly mounting said nozzle on said operating rod with said nozzle being axially movable with respect to said movable con-tact. Piston meanS are connected to said operating rod for producing a flow of gas through said nozzle and through the arc space produced by the separation of said movable and stationary contacts. A housing surrounds said contacts, said nozzle and said piston means and is filled with a relatively high dielectric gas. Said nozzle has an internal nozzle throat restriction, and biasing means are provided for biasing said nozzle .~. .
~:`
' 1~38428 ~, , and said movable contact to a position wherein the end of said movable contact is downstream of said nozzle throat restriction. Said operating rod moves said end of said movable contact upstream of said nozzle throat restriction at~a time following the initial movement of said movable contact to its disengaged position, whereby the initial arcing between said movable and stationary contacts occurs in an arcing space downstream of said nozzle throat restriction, and whereby said arcing space is thereafter located downstream of said nozzle throat restriction and is swept free of arcing products by gas flow from said piston means and through said nozzle throat restriction. Said movable contac~, said stationary contact and said nozzle are coaxially disposed and are each generally axially elongated. Preferably, the dielectric gas is sulfur hexafluoride.
The arrangement of the present invention permits release of energy during the initial arcing period in a region which is downstream of the nozzle, so that pressure release can be effected through the relatively open gap between the nozzle wall and the fixed contact as well `
as through the hollow fixed contact if such an arrangement is used. Thus, the undesirable effects on the nozzle of upstream reverse flow and early contamination of the nozzle throat are largely overcome.
` There is also a reduction of total energy release by elimin-:~ :, ..ating or reducing gas blast in the early part of the opening stroke (when interruption cannot be effected) so that arc voltage and thus arc ,~
energy can be kept lower. There is also a reduction of the swept volume necessary in the puffer piston due to the elimination of the need to clear away initial upstream arc products which reach the piston region and a reduction of useless gas flow when the contact gap is too small to effect an eruption. That is to say, the actual time at which contact separation occurs may be slightly delayed while the nozzle moves relative ~`'''',''' '' ~ : :
_4_ ~` ;`
;
. 1~384Z8 to the contact and toward a position in which the contact is downstream of the nozzle throat. This same time delay also allows time for a gas -pressure differential to build to a sufficiently high value to enable . , .
interruption of the arc when the contacts open. A further advantage `~
obtained by the invention is an improvement in capacitor switching per-formance by minimizing the possibility of interruption of the arc while the contacts are still very close together so that restrike is more probable.
The invention will now be described further by way of example ;
only and with reference to the accompanying drawings wherein:
FIGURE 1 is a cross-sectional view of a portion of an inter-rupter which falls within the concept of the invention, with the contacts in their closed position and wherein the nozzle is fixed to the operating rod while the movable contact is flexibly connected to the operating rod.
FIGURE 2 shows the interrupter of Figure 1 immediately after -the contacts have separated, with the separating contacts being down-stream of the nozzle throat.
FIGURE 3 shows the interrupter of Figures 1 and 2, with the contacts in their fully open position.
FIGURE 4 shows in cross-sectional view an embodiment of the invention as particularly claimed, wherein the stationary contact is fixed to the operating rod, while the nozzle is flexibly connected to -the operating rod.
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~038428 Figure 5 shows the in-terrupter of Figure 4 just after the contacts have separated, with the initial arc being formed at a location downstream of the nozzle throat.
Figure 6 shows the embodiment of Figures 3 and 4 after the contacts are fully opened and the nozzle is retracted to effect a greater open gap distance.
DETAILED DESCRIPTION OF THE DRAWINGS
.
Referring first to Figures 1, 2 and 3, there is shown - a portion of a puffer breaker which includes a stationary conductive piston 10 which can be connected to a first terminal 11 of the breaker. The member 10 may be contained within a suitable housing shown schematically by the dotted block 12, ' which is filled with sulfur hexafluoride at some positive - pressure. Other gases and gas mixtures could also be used if desired.
A conductive operating rod 13 then terminates in an enlarged head 14 which may be segmented if desired, and is in sliding engagement with movable contact cylinder 15. The movable contact cylinder 15 may be segmented into fingers at its right-hand end, where the fingers engage the stationary tubular contact 16. Operating rod 13 is then electrically connected to the stationary conductive member 10 by suitable sliding contact members 17.
- The conductive member 15 may then terminate in an annular disk-shaped end region 18 and may have arcing contact finger type elements 19 at its right-hand end which engage the arcing contact end of stationary contact 16. Movable contact 15 is then supported within an insulation cup 20 which extends from disk 21 which is fixed to the interior - 30 of the baffle cylinder or nozzle 22. The baffle cylinder 22 then consists of a cylindrical body 23 having a restricted nozzle throat 24 where baffle cylinder 23 is slidable on the stationary member 10 which serves as a stationary ' 103842~
piston for the puffer interrupter.
The disk 21 then has a plurality of openings including openings 25 and 26 therein which permit the fl~w of gas from the volume between disk 21 and member 10 to flow to the right and through the nozzle throat 24 when ., .. ~
; the circuit breaker is opened as will be later described~ ~
A sliding seal 30 may be provided between :
; stationary member 10 and cylindrical portion 23 of the nozzle ~ ~
, -: . ., 22 if desired. A biasing spring 35 is then captured within 10 insulation cup 20 and biases contact cylinder 15 to the '~
left and into its seat in the plate 21. Note that the movable components of the breaker are all connected to one another and consist of the operating rod 13, plate 21 and baffle 22. These components move as a single unit when ~, :
operating forces are applied to the operating rod 13.
In order to move contact 15 to the right and i~
I toward its engaged position, the left-hand end of contact,~ , 15 is picked up by the plate 21 and is driven to the right with the operating rod 13. In order to move the contact to its open position, the operating rod 13 moves to the left. ' : ~^,. :
The operation of the interrupter shown in Figure 1 is as follows:
- The contacts are shown in their normally closed ~ -position in Figure 1. In order to open the breaker, the ~' operating rod 13 is moved to the left. The initial movement of operating rod 13 and of disk 21 and nozzle 22 to the left is independent of the movement of contact 15 which is held in position since the frictional engagement forces between 30 inwardly turned contact end 19 and the stationary contact 16 ;~
are greater than the initial force from spring 35.
When the movable contacts reach the position of .
1038g28 - Figure 2, the spring 35 has been compressed to a point where it is able to overcome the engagement forces bet-ween contact 15 and stationary contact 16, and the region of contact disengagement is now downstream of the nozzle throat 24. Consequently, as the contacts separate in Figure 2, the initial arcing is downstream of the nozzle throat 24 resulting in low-arc energy and minimum pres-sure effect upstream of the nozzle. It should be further noted that the pressure created by the initial downstream arc will bear against surface 40 of throat 24, thereby to provide a pressure assist in the movement of the movable components to the left during the opening of the breaker. The spring 35 accelerates contact 15 to the left, thereby increasing the effective speed with which a contact gap is achieved. Furthermore, the contact 15 blocks nozzle 40 to eliminate gas flow and pressure loss before the contacts reach a point where effective inter-- ruption can be obtained. -As the moving components continue to move to the left, the movable contact ultimately reaches the preferred position which is upstream of the nozzle throat 24, which is most favorable for arc interruption and prevention of ,-restrike. It will be noted that, during this operation, relatively little ionized gas and contaminated arc pro-ducts will flow back toward the piston area or the region between disk 21 and tpe end of stationary member 10.
Figures 4, 5 and 6 show a preferred embodiment of the invention which differs from the embodiments of Figures 1, 2 and 3 in that the relatively movable components in Figures 4 to 6 is the nozzle portion of the movable system rathér than the contact portion of the movable system as `
in Figures 1, 2 and 3.
,: .. , ' . , :. : . . . : : .
103842B ~ ~
Referring now to Figures 4, 5 and 6, the puffer interrupter consists of a fixed puffer piston 50 which may be of conductive material and which slidably receive~
a puffer cylinder 51 which is fixed to the movable contact operating rod 52 by the plate 53. Note that plate 53 is similar to plate 21 of Figures 1, 2 and 3 and contains suitable openings, such as openings 54 and 55 which per-mit the flow of gas into the interrupting area upon the movement of the puffer cylinder 51 to the left. The ; 10 moving contact rod 52 may then be electrically connected to the conductive piston 50 by transfer contacts 56 and one terminal of the breaker may be connected to the - puffer piston 50 and is shown as the terminal 57. The ..
right-hand end of the contact operating rod 52 then carries a segmented movable contact member 60 which coop-erates with a stationary contact tube 61 which defines the second terminal 62 of the breaker.
The contacts 60 and 61 are then surrounded by nozzle 63 which is flexibly carried on the puffer cylinder by the compression spring 70 which is disposed between the inwardly turned flange 71 of cylinder 51 and the outwardly turned flange 72 of nozzle 63. Note that nozzle 63, like nozzle 22 of Figures 1, 2 and 3, is of any desired insulation material.
The operation of the system of Figures 4 to 6 is as follows: ~
In order to open the breaker, the operating rod 52 is initially moved to the left from the position of Figure 4 toward the position of Figure 5. At this time the movable operating rod 52, plate 53, cylinder 51 and nozzle 63 move as a unit to the left and the throat of the nozzle 63 moves with contact fingers 60. During this time, , ~,, ' .
. - . . .. .
10384~8 the major portion of the nozzle throat is generally down-stream of the contact region at which initial arcing will take place when the position of Figure Z is reached.
The contact 60 is substantially blocking gas flow through the nozzle 63, thus promoting early build-up of pressure upstream of the contacts.
Once the position of Figure 2 is reached, a pressure within nozzle 63 and against interior surface 63a has been reached to move the nozzle 63 to the dotted-line position which is the interrupting position for the nozzle and for the system. However, this position is not assumed until sufficient internal pressure has been produced to ensure effective arc interruption and clearing of arc products from the interruption space.
At the same time, the nozzle is moved to its interrupt-ing position only after a suitable interrupting gap has been reached between the contacts 60 and 61. Thusr the initial arcing will be downstream of the nozzle to result in minimum pressure effects upstream of the nozzle while the initial interrupting position is reached with all components in their preferred position to obtain effective permanent interruption.
Note further that, if there is extensive down-stream pressure which is arc-generated on surface 63b of nozzle 63, this excess pressure will prevent the -nozzle 63 from moving to its position in Figure 5 until ; a sufficient pressure differential is developed across the nozzle throat to permit effective interruption.
After the interruption operation, the nozzle 63 is spring-retracted to the position shown in Figure 6 with the contacts in their fully open position.
_g_ , . . .
~ lthougll tJIis invcntion h~s bcen dcscri~cd witll respect t~ its preferred cmbodiments, it should be understood that many variations and modifications will now be obvious to those skilled in the art, and it is preferred, thcrefore, that the scope of the invention be limited not by the specific disclosure herein, but only by the appended claims.
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'` ~
. . . .
During the opening stroke of the movable contact, it is also desirable to keep the energy released in the arc space to a minimum and to release this energy in such --a manner as to minimize its effect on the interior components and to minimize the forces necessary to operate the interrupter.
In puffer interrupters of this type, it is common practice to fix a movable contact to the nozzle so that both move relative to a stationary contact, and further to fix the end of the movable contact at some fixed and preferred location which is upstream of the interrupter nozzle throat. The arc which is drawn between the separating contacts in such a device is then initiated upstream of the nozzle and will be drawn through the nozzle throat during the first part of the opening stroke.
During the opening stroke and as pointed out above, the arc produces various types of arcing products and ionized gas in the region which is upstream of the nozzle so that these products and ionized gases must be swept free if inter-ruption is to be obtained. Moreover, the arc and heated gases produced by the arc are immediately adjacent to the no~zle and the nozzle throat, thereby causing thermal deterioration of the nozzle which can reduce the interrupting lifetime of the device.
A further disadvantage of the fixed positioning of the movable contact upstream of the nozzle throat is that the ,- ,, , ~ : ~ . . .
initial arc which is drawn will cause a high-pressure zone in the nozzle :~-throat which results in a back pressure which must be overcome by higher operating forces from the operating mechanism. Note further that the back pressure in the nozzle can result momentarily in a back flow of gas so that arc products could be brought into the puffer piston area.
In accordance with the invention, the movable contact and the movable nozzle are movably connected to one another and the movable contact is normally biased to a preferred location slightly upstream of the nozzle -throat. However, upon operation of the interrupter, the movable contact and nozzle move relative to one another so that the end of the movable contact is downstream of the nozzle throat at the time an arc is initiated -between the separating contacts. Following the initial arcing interval, ;~ -the movable contact returns to its preferred upstream location relative to the nozzle, when a sufficiently large open gap is formed to withstand the crest of the system recovery voltage and enough pressure has developed ;
to produce effective arc sweeping action.
Therefore, according to this invention, a puffer type circuit ; interrupter comprises a stationary elongated contact and a movable contact movable between an engaged and disengaged position with said stationary contact. An insulation nozzle surrounds said movable and stationary - contacts and an operating rod is connected to said movable contact, means being provided for flexibly mounting said nozzle on said operating rod with said nozzle being axially movable with respect to said movable con-tact. Piston meanS are connected to said operating rod for producing a flow of gas through said nozzle and through the arc space produced by the separation of said movable and stationary contacts. A housing surrounds said contacts, said nozzle and said piston means and is filled with a relatively high dielectric gas. Said nozzle has an internal nozzle throat restriction, and biasing means are provided for biasing said nozzle .~. .
~:`
' 1~38428 ~, , and said movable contact to a position wherein the end of said movable contact is downstream of said nozzle throat restriction. Said operating rod moves said end of said movable contact upstream of said nozzle throat restriction at~a time following the initial movement of said movable contact to its disengaged position, whereby the initial arcing between said movable and stationary contacts occurs in an arcing space downstream of said nozzle throat restriction, and whereby said arcing space is thereafter located downstream of said nozzle throat restriction and is swept free of arcing products by gas flow from said piston means and through said nozzle throat restriction. Said movable contac~, said stationary contact and said nozzle are coaxially disposed and are each generally axially elongated. Preferably, the dielectric gas is sulfur hexafluoride.
The arrangement of the present invention permits release of energy during the initial arcing period in a region which is downstream of the nozzle, so that pressure release can be effected through the relatively open gap between the nozzle wall and the fixed contact as well `
as through the hollow fixed contact if such an arrangement is used. Thus, the undesirable effects on the nozzle of upstream reverse flow and early contamination of the nozzle throat are largely overcome.
` There is also a reduction of total energy release by elimin-:~ :, ..ating or reducing gas blast in the early part of the opening stroke (when interruption cannot be effected) so that arc voltage and thus arc ,~
energy can be kept lower. There is also a reduction of the swept volume necessary in the puffer piston due to the elimination of the need to clear away initial upstream arc products which reach the piston region and a reduction of useless gas flow when the contact gap is too small to effect an eruption. That is to say, the actual time at which contact separation occurs may be slightly delayed while the nozzle moves relative ~`'''',''' '' ~ : :
_4_ ~` ;`
;
. 1~384Z8 to the contact and toward a position in which the contact is downstream of the nozzle throat. This same time delay also allows time for a gas -pressure differential to build to a sufficiently high value to enable . , .
interruption of the arc when the contacts open. A further advantage `~
obtained by the invention is an improvement in capacitor switching per-formance by minimizing the possibility of interruption of the arc while the contacts are still very close together so that restrike is more probable.
The invention will now be described further by way of example ;
only and with reference to the accompanying drawings wherein:
FIGURE 1 is a cross-sectional view of a portion of an inter-rupter which falls within the concept of the invention, with the contacts in their closed position and wherein the nozzle is fixed to the operating rod while the movable contact is flexibly connected to the operating rod.
FIGURE 2 shows the interrupter of Figure 1 immediately after -the contacts have separated, with the separating contacts being down-stream of the nozzle throat.
FIGURE 3 shows the interrupter of Figures 1 and 2, with the contacts in their fully open position.
FIGURE 4 shows in cross-sectional view an embodiment of the invention as particularly claimed, wherein the stationary contact is fixed to the operating rod, while the nozzle is flexibly connected to -the operating rod.
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- ~ : ., . :
~038428 Figure 5 shows the in-terrupter of Figure 4 just after the contacts have separated, with the initial arc being formed at a location downstream of the nozzle throat.
Figure 6 shows the embodiment of Figures 3 and 4 after the contacts are fully opened and the nozzle is retracted to effect a greater open gap distance.
DETAILED DESCRIPTION OF THE DRAWINGS
.
Referring first to Figures 1, 2 and 3, there is shown - a portion of a puffer breaker which includes a stationary conductive piston 10 which can be connected to a first terminal 11 of the breaker. The member 10 may be contained within a suitable housing shown schematically by the dotted block 12, ' which is filled with sulfur hexafluoride at some positive - pressure. Other gases and gas mixtures could also be used if desired.
A conductive operating rod 13 then terminates in an enlarged head 14 which may be segmented if desired, and is in sliding engagement with movable contact cylinder 15. The movable contact cylinder 15 may be segmented into fingers at its right-hand end, where the fingers engage the stationary tubular contact 16. Operating rod 13 is then electrically connected to the stationary conductive member 10 by suitable sliding contact members 17.
- The conductive member 15 may then terminate in an annular disk-shaped end region 18 and may have arcing contact finger type elements 19 at its right-hand end which engage the arcing contact end of stationary contact 16. Movable contact 15 is then supported within an insulation cup 20 which extends from disk 21 which is fixed to the interior - 30 of the baffle cylinder or nozzle 22. The baffle cylinder 22 then consists of a cylindrical body 23 having a restricted nozzle throat 24 where baffle cylinder 23 is slidable on the stationary member 10 which serves as a stationary ' 103842~
piston for the puffer interrupter.
The disk 21 then has a plurality of openings including openings 25 and 26 therein which permit the fl~w of gas from the volume between disk 21 and member 10 to flow to the right and through the nozzle throat 24 when ., .. ~
; the circuit breaker is opened as will be later described~ ~
A sliding seal 30 may be provided between :
; stationary member 10 and cylindrical portion 23 of the nozzle ~ ~
, -: . ., 22 if desired. A biasing spring 35 is then captured within 10 insulation cup 20 and biases contact cylinder 15 to the '~
left and into its seat in the plate 21. Note that the movable components of the breaker are all connected to one another and consist of the operating rod 13, plate 21 and baffle 22. These components move as a single unit when ~, :
operating forces are applied to the operating rod 13.
In order to move contact 15 to the right and i~
I toward its engaged position, the left-hand end of contact,~ , 15 is picked up by the plate 21 and is driven to the right with the operating rod 13. In order to move the contact to its open position, the operating rod 13 moves to the left. ' : ~^,. :
The operation of the interrupter shown in Figure 1 is as follows:
- The contacts are shown in their normally closed ~ -position in Figure 1. In order to open the breaker, the ~' operating rod 13 is moved to the left. The initial movement of operating rod 13 and of disk 21 and nozzle 22 to the left is independent of the movement of contact 15 which is held in position since the frictional engagement forces between 30 inwardly turned contact end 19 and the stationary contact 16 ;~
are greater than the initial force from spring 35.
When the movable contacts reach the position of .
1038g28 - Figure 2, the spring 35 has been compressed to a point where it is able to overcome the engagement forces bet-ween contact 15 and stationary contact 16, and the region of contact disengagement is now downstream of the nozzle throat 24. Consequently, as the contacts separate in Figure 2, the initial arcing is downstream of the nozzle throat 24 resulting in low-arc energy and minimum pres-sure effect upstream of the nozzle. It should be further noted that the pressure created by the initial downstream arc will bear against surface 40 of throat 24, thereby to provide a pressure assist in the movement of the movable components to the left during the opening of the breaker. The spring 35 accelerates contact 15 to the left, thereby increasing the effective speed with which a contact gap is achieved. Furthermore, the contact 15 blocks nozzle 40 to eliminate gas flow and pressure loss before the contacts reach a point where effective inter-- ruption can be obtained. -As the moving components continue to move to the left, the movable contact ultimately reaches the preferred position which is upstream of the nozzle throat 24, which is most favorable for arc interruption and prevention of ,-restrike. It will be noted that, during this operation, relatively little ionized gas and contaminated arc pro-ducts will flow back toward the piston area or the region between disk 21 and tpe end of stationary member 10.
Figures 4, 5 and 6 show a preferred embodiment of the invention which differs from the embodiments of Figures 1, 2 and 3 in that the relatively movable components in Figures 4 to 6 is the nozzle portion of the movable system rathér than the contact portion of the movable system as `
in Figures 1, 2 and 3.
,: .. , ' . , :. : . . . : : .
103842B ~ ~
Referring now to Figures 4, 5 and 6, the puffer interrupter consists of a fixed puffer piston 50 which may be of conductive material and which slidably receive~
a puffer cylinder 51 which is fixed to the movable contact operating rod 52 by the plate 53. Note that plate 53 is similar to plate 21 of Figures 1, 2 and 3 and contains suitable openings, such as openings 54 and 55 which per-mit the flow of gas into the interrupting area upon the movement of the puffer cylinder 51 to the left. The ; 10 moving contact rod 52 may then be electrically connected to the conductive piston 50 by transfer contacts 56 and one terminal of the breaker may be connected to the - puffer piston 50 and is shown as the terminal 57. The ..
right-hand end of the contact operating rod 52 then carries a segmented movable contact member 60 which coop-erates with a stationary contact tube 61 which defines the second terminal 62 of the breaker.
The contacts 60 and 61 are then surrounded by nozzle 63 which is flexibly carried on the puffer cylinder by the compression spring 70 which is disposed between the inwardly turned flange 71 of cylinder 51 and the outwardly turned flange 72 of nozzle 63. Note that nozzle 63, like nozzle 22 of Figures 1, 2 and 3, is of any desired insulation material.
The operation of the system of Figures 4 to 6 is as follows: ~
In order to open the breaker, the operating rod 52 is initially moved to the left from the position of Figure 4 toward the position of Figure 5. At this time the movable operating rod 52, plate 53, cylinder 51 and nozzle 63 move as a unit to the left and the throat of the nozzle 63 moves with contact fingers 60. During this time, , ~,, ' .
. - . . .. .
10384~8 the major portion of the nozzle throat is generally down-stream of the contact region at which initial arcing will take place when the position of Figure Z is reached.
The contact 60 is substantially blocking gas flow through the nozzle 63, thus promoting early build-up of pressure upstream of the contacts.
Once the position of Figure 2 is reached, a pressure within nozzle 63 and against interior surface 63a has been reached to move the nozzle 63 to the dotted-line position which is the interrupting position for the nozzle and for the system. However, this position is not assumed until sufficient internal pressure has been produced to ensure effective arc interruption and clearing of arc products from the interruption space.
At the same time, the nozzle is moved to its interrupt-ing position only after a suitable interrupting gap has been reached between the contacts 60 and 61. Thusr the initial arcing will be downstream of the nozzle to result in minimum pressure effects upstream of the nozzle while the initial interrupting position is reached with all components in their preferred position to obtain effective permanent interruption.
Note further that, if there is extensive down-stream pressure which is arc-generated on surface 63b of nozzle 63, this excess pressure will prevent the -nozzle 63 from moving to its position in Figure 5 until ; a sufficient pressure differential is developed across the nozzle throat to permit effective interruption.
After the interruption operation, the nozzle 63 is spring-retracted to the position shown in Figure 6 with the contacts in their fully open position.
_g_ , . . .
~ lthougll tJIis invcntion h~s bcen dcscri~cd witll respect t~ its preferred cmbodiments, it should be understood that many variations and modifications will now be obvious to those skilled in the art, and it is preferred, thcrefore, that the scope of the invention be limited not by the specific disclosure herein, but only by the appended claims.
.
'` ~
. . . .
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a puffer type circuit interrupter; said puffer type circuit interrupter comprising a stationary elongated contact; a movable contact movable between an engaged and disengaged position with said stationary contact; an insulation nozzle surrounding said movable and stationary contacts; an operating rod connected to said movable contact; means for flexibly mounting said nozzle on said operating rod with said nozzle being axially movable with respect to said movable contact; piston means connected to said operating rod for pro-ducing a flow of gas through said nozzle and through the arc space produced by the separation of said movable and stationary contacts; a housing surrounding said contacts, said nozzle and said piston means and filled with a relatively high dielectric gas; said nozzle having an internal nozzle throat restriction;
biasing means for biasing said nozzle and said movable contact to a position wherein the end of said movable contact is down-stream of said nozzle throat restriction; said operating rod moving said end of said movable contact upstream of said nozzle throat restriction at a time following the initial movement of said movable contact to its disengaged position, whereby the initial arcing between said movable and stationary contacts occurs in an arcing space downstream of said nozzle throat restriction, and whereby said arcing space is thereafter located downstream of said nozzle throat restriction and is swept free of arcing products by gas flow from said piston means and through said nozzle throat restriction; said movable contact, said stationary contact and said nozzle each being coaxially disposed and each being generally axially elongated.
biasing means for biasing said nozzle and said movable contact to a position wherein the end of said movable contact is down-stream of said nozzle throat restriction; said operating rod moving said end of said movable contact upstream of said nozzle throat restriction at a time following the initial movement of said movable contact to its disengaged position, whereby the initial arcing between said movable and stationary contacts occurs in an arcing space downstream of said nozzle throat restriction, and whereby said arcing space is thereafter located downstream of said nozzle throat restriction and is swept free of arcing products by gas flow from said piston means and through said nozzle throat restriction; said movable contact, said stationary contact and said nozzle each being coaxially disposed and each being generally axially elongated.
2. The puffer circuit interrupter of claim 1 wherein said dielectric gas is sulfur hexafluoride.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA293,244A CA1042040A (en) | 1974-05-02 | 1977-12-16 | Puffer interrupter with down stream initiated arc |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US466408A US3914569A (en) | 1974-05-02 | 1974-05-02 | Puffer interrupter with downstream initiated arc |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1038428A true CA1038428A (en) | 1978-09-12 |
Family
ID=23851638
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA216,189A Expired CA1038428A (en) | 1974-05-02 | 1974-12-17 | Puffer interrupter with down stream initiated arc |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3914569A (en) |
| CA (1) | CA1038428A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4103130A (en) * | 1975-01-29 | 1978-07-25 | Westinghouse Electric Corp. | Resistor applications for high-power circuit breakers |
| JPS5461259U (en) * | 1977-10-07 | 1979-04-27 | ||
| DE3322597A1 (en) * | 1983-05-31 | 1984-12-06 | BBC Aktiengesellschaft Brown, Boveri & Cie., Baden, Aargau | EXHAUST GAS SWITCH |
| FR2762925B1 (en) * | 1997-05-02 | 1999-07-09 | Gec Alsthom T & D Sa | HIGH VOLTAGE CIRCUIT BREAKER WITH DOUBLE MOTION OF ARC CONTACTS |
| JP2006164673A (en) * | 2004-12-06 | 2006-06-22 | Hitachi Ltd | Current breaking method of puffer type gas-blast circuit breaker and puffer type gas-blast circuit breaker using it |
| FR2944135B1 (en) * | 2009-04-03 | 2011-06-10 | Areva T & D Sa | MOBILE CONTACT CURRENT CHAMBER AND MOBILE BLOWING NOZZLE INDEPENDENT MANUFACTURERS, SWITCH BY PASS HVDC AND UNDER HVDC CONVERSION STATION COMPRISING SUCH A ROOM. |
| FR2957451A1 (en) * | 2010-03-09 | 2011-09-16 | Areva T & D Sas | HIGH VOLTAGE ELECTRIC SWITCH WITH CLOSURE RETURN AND DEVICE FOR INSERTING RESISTANCE |
| FR2989013B1 (en) * | 2012-04-04 | 2014-04-11 | Air Liquide | LASER NOZZLE WITH MOBILE ELEMENT WITH IMPROVED EXTERNAL PROFILE |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2014101C2 (en) * | 1970-03-19 | 1982-06-03 | Siemens AG, 1000 Berlin und 8000 München | High voltage circuit breaker |
| US3739125A (en) * | 1972-04-27 | 1973-06-12 | Gen Electric | Puffer type gas blast circuit breaker |
| US3769479A (en) * | 1972-04-28 | 1973-10-30 | Westinghouse Electric Corp | Puffer-type compressed-gas circuit interrupter with double-flow action |
-
1974
- 1974-05-02 US US466408A patent/US3914569A/en not_active Expired - Lifetime
- 1974-12-17 CA CA216,189A patent/CA1038428A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US3914569A (en) | 1975-10-21 |
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