US3160727A

US3160727A - Gas-blast orifice-type interrupting unit

Info

Publication number: US3160727A
Authority: US
Priority date: 1961-10-24
Publication date: 1964-12-08
Anticipated expiration: 1981-12-08
Also published as: DE1194949B; GB1014013A

Description

1964 R. G. COLCLASER, JR. ETAL 3,160,727

GAS-BLAST ORIFICE-TYPE INTERRUFTING UNIT WITH RESISTANCE ORIFICE MEMBER Filed 001.. 24, 1961 4 Sheets-Sheet 1 2 w M w J 9 co n v i .1 ca

I m In I0 I N l l I '2 A I: 3 O a INVENTORS WITNESSES Robert G. Colc|user,Jr. 8 QBW -Q 6' Russell N. Yeckley.

Dec. 8, 1964 R. G. COLCLASER, JR. ETAL GASBLAST ORIFICE-TYPE INTERRUPTING UNIT WITH RESISTANCE ORIFICE MEMBER 4 Sheets-Sheet 2 Filed Oct. 24, 1961 Q g wLl i? v m o. 6 U 2. L t. I m MN N 5 mm mm 3 08 5 E88: :9: BTNN m Dec. 8, 1964 R. G. COLCLASER, JR, ETAL ,160, 7

GAS-BLAST ORIFICEFTYPE INTERRUPTING UNIT WITH RESISTANCE ORIFICE MEMBER Filed Oct. 24, 1961 4 Sheets$heet 3 SISTANCE MATERIAL INSULATION Dec. 8, 1964 R. G. COLCLASER, JR, ETAL 3, 0,

GAS-BLAST ORIFICE-TYPE INTERRUPTING UNIT WITH RESISTANCE ORIF'ICE MEMBER Filed Oct. 24, 1961 I 4 Sheets-Sheet 4 as RESISTANCE MATERIAL United States Patent 3,16%,727 GAS-BLAST GREECE-TYPE lNTEllRUPTlNG UNlT WITH RESISTANCE ORIFICE MEMBER Robert G. Colclaser, .lr., Belmont, and Russell N. Yeckley, Franklin Township, Wcstmoreland County, Pa,

assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Oct. 24, 1961, Ser. No. 147,237 3 Claims. (Cl. 200-448) This invention relates to circuit interrupters in general and, more particularly, to improved arc-extinguishing structures therefor.

A general object of the present invention is to provide an improved circuit-interrupting structure highly effective to extinguish currents over a wide current range and particularly effective in the higher current range.

In United States patent application filed January 23, 1959, Serial No. 788,668, now United States Patent 3,057- 983, issued October 9, 1962 to Russell N. Yeckley, Joseph Sucha and Benjamin P. Baker, and assigned to the assignee of the instant application, there is described and claimed an interrupting unit of the gas-blast type in which a suitable arc-extinguishing gas is exhausted axially along an orifice structure in proximity to the established arc. T his interrupter is highly effective throughout a wide current range. However, during very high-current interruptions, there is a tendency for a high-current limit to be reached because the orifice opening is clogged by the highcurrent arc, thereby preventing the rapid flow of gas, such as sulfur hexafluoride (SP gas, necessary for quick interruption. The arc, in such circumstances, may persist for two or more cycles and be difiicult to interrupt. Accordingly, it is a purpose of the present invention to provide an improved type of interrupter construction in which a cross-blast flow of gas will be obtained particularly for effective high current interruption.

Still a further object of the present invention is to provide an improved orifice-type interrupting unit in which a resistance is inserted serially into the connected circuit during interruption to lower the rate of rise of the recovery voltage, and to assist in rapid are interruption.

Yet a further object of the present invention is to provide an improved orifice construction particularly suitable for withstanding high voltage tests and to eliminate the aforesaid clogging action by utilizing a metallic orifice to shield the stationary contact during such voltage tests, and, in addition, to eliminate the presence of an arc portion within the orifice itself.

Further objects and advantages will readily become apparent upon reading the following specification, taken in conjunction with the drawings, in which:

FIGURE 1 isa perspective view of a three-pole highpower circuit interrupter suitable for controlling the three phases of a transmission system, and illustrating an embodiment of the present invention;

FIG. 2 is a longitudinal vertical sectional view taken through one of the grounded tank structures of FIG. 1, illustrating the arc-extinguishing assemblage in side elevation, and showing the disposition of the contact structure in the closed-circuit position thereof;

FIG. 3 is an enlarged vertical sectional View taken longitudinally through one of the improved arc-extinguishing units of the multi-break arc-extinguisl1ing assemblage of FIG. 2, the contact structure being illustrated in the closed-circuit position;

FIG. 4 is a fragmentary sectional view, somewhat similar to that of FIG. 3, but showing the location of the drawn arc during a portion of the opening operation;

FIG. 5 is an enlarged sectional View taken substantially along the line VV of FIG. 3;

FIG. 6 is a fragmentary view of a modified type of circuit-interrupting unit, the contact structure being illustrated in the partially open-circuit position;

FIG. 6A illustrates a slightly modified form of the circuit-interrupting unit of FIG. 6, again the contact structure being illustrated in the partially open-circuit position;

FIG. 7 illustrates, in vertical cross section, still a further modified type of interrupting unit;

FIG. 8 illustrates a fragmentary plan view of the movable contact assemblage taken substantially along the line VIII-VH1 of FIG. 3, with certain parts omitted for clarity; and,

FIGS. 9 and 10 show a modified type interrupting unit in two consecutive intermediate positions of the opening operation.

Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 generally designates a three-pole high-voltage, high-power circuit interrupter suitable for controlling the three phases of a transmission system. Pole-unit A controls the lines L and L pole-unit B controls the transmission line L L and pole-unit C controls the current phase passing through line L L As shown, the circuit interrupter 1 comprises a plurality of generally horizontally-extending grounded metallic tank structures 2 having end covers 3 associated therewith. The end covers 3 may be rotated about vertical hinge pins, not shown, to permit inspection into the interior of the tank structures 2 and withdrawal of the arc-extinguishing assemblage 4 (FIG. 2) laterally out of the tank structure 2 when such a maintenance operation is desired.

Disposed at opposite ends of the several tank structures 2, and extending upwardly therefrom, are supporting cylinders 5 having flanged apertured upper support plates c, the latter serving to rigidly support into position entrance-type terminal bushing structures 7. As well known by those skilled in the art, the terminal bushings 7 serve the function of transmitting the current to be interrupted into the interior of the tank structures 2. In addition, as more clearly shown in RIG. 2, the lower ends 25 of the terminal bushings 'i serve to support the arcextinguishlng assemblage 4, in bridging relation therewith, in a relatively fixed position.

Disposed below each of the horizontally-extending elongated tank structures 2 are auxiliary high-pressure storage tanks ll, which cooperate with the high-pressure reservoir chamber llA (FlG, 2) which is disposed at the right-hand end of each of the several arc-extinguishing assemblages 4, as more clearly shown in FIG. 2. A mechanism housing 12 is provided which encloses the gas-control equipment, and a suitable compressor, not shown, which is employed to extract relatively low-pressure gas from the interior 13 of the several tank structures 2 and to rccomprcss it, forcing the recompressed gas back, by a suitable pipeline, not shown, to the auailiarly highpressure reservoirs 11 and MA. A high-pressure connecting tube 14 (FIG. 2) interconnects each higl1-pressure reservoir 11 with the high-pressure reservoir 11A, which constitutes the right-hand extremity of each arc-extinguishing assemblage 4-, as more clearly shown in FIG. 2,

Disposed intcriorly within the mechanism housing 12 is a suitable operating mechanism, for example one of the pneumatic type, which functions, by a suitable linkage, to efifect reciprocal motion of an operating shaft, not shown, disposed interiorly within an operating tube 15 (FIG. 1) which interconnects the several pole-units A, B and C.

Encircling each of the terminal bushings 7 are current transformers 16, which serve to measure the current flow through the circuit interrupter l and also serve thereby to operate protective relaying equipment. Conduits 17 serve to carry the secondary leads of the current transformers areas-a7 16 interiorly within the mechanism housing 12, in which a trip mechanism may be positioned.

With reference to FIG. 2, it will be observed that th arc-extinguishing assemblage t includes a rigid framework maintained in fixed position by insulating support bars l8, which are bolted, as at 19, Ztl to support

castings

21, 22. The support castings Z1, 22 are fixedly secured to the lower ends 8 to the terminal bushings 7. As shown, the high-pressure reservoir chamber MA is bolted to the right-hand support bracket 22 of the arc-extinguishing assemblage 4-.

Associated with the high-pressure reservoir chamber 11A is a blast valve 23 (MG. 3) biased to the closed position by a compression spring 24, and opened by a pilotvalve assembly 27 (FIG. 2) as set out more in detail in the aforesaid patent application. The blast valve 23 is operated by a pneumatic valve piston, not shown, which, in turn, is operated by the pilot-valve assembly 27 (FEG. 2), operated by a main operating lever 23, pivctally mounted at The main operating lever 23 has a pair of thrust-links 31 only one being shown in PE 2) pivotally secured thereto, as at The left-hand ends of the two thrust-links 31, as viewed in FIG. 2, are pivotally con nected to the right-hand ends of the two spaced movable operating rods 33 (FIG. 2), which move in a reciprocal manner, back and forth, during the opening and closing operations, as viewed in FIGS. 1 and 2.

interconnecting the left-hand ends of the two spaced. insulating operating rods 33, as viewed in FIG. 2, is a bridging spring-plate 34, which is biased toward the left by a compression spring 35. At the end of the opening operation, the spring-plate 3d strikes t.e bumper stop 36 and is arrested thereby bringing the entire movable contact assemblage to a cushioned stop.

Spaced axially along the insulating operating rods 33, and bridging the two operating rods 33, are a pluralty of movable contact cross-arms 37 (FIG. 8). The crossarms 37 are pinned to the two spaced insulating operating rods 33, and form a generally movable ladder-like contact assemblage 3?. Adjacent the center of each cross-arm 37 (FIG. 8) is pinned, by a guide pin 38, an extension 41 of a movable contact As shown more clearly in FIG. 3, the movable contact 42 makes contacting engagement with a relatively stationary contact 43, the latter having a plurality of resilient end fingers Preferably are resisting tip portions 4 4A are associated with the extremities of the resilient finger contacts id to assume the arcing during the opening operation. The end of the movable contact is provided with a vented recessed portion do, within which projects the left-hand end of the relatively stationary contact 43, as shown in 3 of the drt wings. A plurality of lateral vents 3 5A communicate with the recess portion 46 of movable contact 42, as shown.

Surrounding the relatively stationary and

movable contacts

42, 43 in the closed-circuit position of the device, as illustrated in P16. 3, is a metallic orifice structure, generally designated by the reference numeral 43. As shown, the orifice structure includes a removable orifice plate 49, which preferaly has an arc-resisting orifice liner As shown in FIG. 3, in the closed-circuit position of the interrupter l, the movable contact 42, extends through the orifice opening 51 and makes contacting engagement with the relatively stationary contact 43. Due to the resiliency of the relatively stationary contact fingers 4d, a good current transfer is obtained therebetwcen.

An insulating gas-directing tube 4! is associated with each unit ill, being disposed forwardly of the orifice opening 51, and defining an outer interrupting chamber generally designated by the reference number 52.

During the opening operation, the movable operating rods are moved toward the left, as viewed in HG. 3, causing thereby a separation between the several movable contacts and the relatively stationary contacts as of the several interrupting units ill? to establish a plurality of serially related arcs 513. Since the orifice structure of each interrupting unit lit is composed of a metallic material, the are 53 quickly transfers from the relatively stationary contact 43 to the orifice liner 5% in a manner more clearly shown in FIG. 4 of the drawings. in addition,

ES. 4 shows a modified type movable contact 42A hav' ing an unvented recess 46, as shown.

As more fully brought out in the aforesaid patent application, the blast valve 23 is opened at, or slightly before the separation of the

movable contacts

42, 43 to cause a blast of high pressure gas to pass from the high-pressure tank 11A through the blast tube structure, or conducting blast entrance chamber 5 and into the orifice region 55'. There occurs a rapid rise of pressure within the orifice region 55 to effect an ejection of bi h-pressure gas out through the constricted orifice opening 51 to direct a cross blast of gas across the are 53, as indicated by the arrows 56 in FlG. 4 of the drawings. It will be noted that even though a very high-current arc is drawn, nevertheless due to the fact that the orifice structure id is composed of metallic material, there will be no arc portion present within the interior region 55 of the orifice structure 4 As shown in FIG. 4, the are 53 will be positioned exteriorly of the orifice structure 48, and will receive the direct cross-blast effect of the high-pressure gas therethrough, which will quickly effect its extinction.

FIG. 6 illustrates a modified type of interrupting unit 58 in which the body of the orifice structure 59 is composed of a suitable resistance material, such as carbon. The magnitude of the resistance in the modified type of interrupting unit 58 of FIG. 6 may vary from substantially 12 ohms to 200 ohms depending upon the current and voltage rating of the circuit-interrupting device.

It will be apparent that upon separation of the movable contact 6t? from the relatively stationary contact 61 a main current are, generally designated by the reference numeral 62, will be established. Because of the presence of the adjacent resistance material comprising the orifice structure, and because of the longitudinally flowing gas blast at high pressure through the constricted orifice opening 51, the main current are will be extinguished, and there will result a residual curent are 63 extending between the tip portion 64 of the movable contact an and the orifice liner 5h. The insertion of the resistance material serially into the circuit will lower the rate of rise of the recovery voltage and will also improve the power factor of the resultant circuit to be interrupted. Again the gas blast will pass in the direction indicated by the arrows 66 of FIG. 6, and the arc will quickly be extinguished.

The interrupter shown in FIG. 6 causes interruption in a manner similar to that of Patent 3,057,983, in that the arc is forced to remain in the center of the orifice 51 by the resistor 59. The axial flow of gas forces interruption. if the are 62 attempts to transfer to the metal orifice 59 immediately after the contacts part, the subsequent voltage rise, caused by the insertion of the resistor, will cause an immediate breakdown of the gap between the contact tip and the fingers 61. The process forces the power are 62 to stay in the center of the orifice 51 until a sufficient gap is available to withstand the recovery voltage. The resistor current 63 will then be interrupted in the manner previously described.

Instead of forming the body of the orifice structure of a suitable resistance material, such as carbon, the same effect may be produced, namely of insertion of the resistance serially into the circuit, by using the construction set forth in FIG. 6A of the drawings. With reference to FIG. 6A, it will be noted that a separate resistance tube *ltl is employed composed of insulating material, surrounding which may be helically wound a resistance wire 71. In this modified construction, the orifice body may be of a suitable insulating material 73. The manner of interruption will be the same as set forth in connection with PEG. 6 of the drawing, namely the interruption of the main current are by the insertion into series circuit of the resistance material. Again the resistance value may vary from say substantially 12 ohms to 200 ohms depending on the current and voltage requirements of the device.

FIG. 7 shows a further modified form of the invention in which a modified type of interrupting unit 75 utilizes a tubular movable contact '76 having slotted portions 77 to form a plurality of circumferentially disposed resilient contact fingers 7?. The contact fingers 7d resiliently engage the interior surface '79 of the orifice liner in a manner more clearly shown in FIG. 7 of the drawings. During the opening operation, the movable contact '76 is drawn toward the left by the left-hand opening movement of the movable contact assemblage 39 in the manner previously described. The orifice structure, being of metallic material, will effect drawing the arc externally of the orifice, in the manner illustrated in FIG. 4 of the drawings. It will be noted in connection with this modification of the invention, that the relatively

stationary contact structure

43, 61 is omitted and the orifice liner fill itself constitutes the relatively stationary contact. Preferably, the outer side of the orifice liner 8% is beveled, as at WA, to assist in guiding the closing movement of the movable contact '76.

FIG. 9 is a modification of the interrupter construction of FIG. 6 wherein the stationary contact 611 has been moved rearwardly of the orifice construction 59. In the modified interrupter unit 85 of FIG. 9, a vented movable contact 85 is utilized. The drawn main or power are $7 is maintained between the moving contact 86 and the stationary contact 61 by the action of the resistor 88. If the main are $7 attempts to transfer to the metal orifice h shortly after the

contacts

86, 61 part, the subsequent voltage, caused by the insertion of the resistor 38, will cause an immediate breakdown of the gap between the contact 61. and the contact 86. The arc is interrupted by the flow of gas through the center of the hollow contact 86. The location of the orifice 5t forces the gas to flow through the center of the contact 86. The power are $7 is generally interrupted before the contact 56 is withdrawn from the orifice 55B. Subsequently, the resistor are 89, as shown in FIG. 10 is interrupted by the gas cross-blast after the contact 36 is withdrawn from the orifice 56.

From the foregoing description of several embodiments of the invention, it will be apparent that there is provided an improved orifice construction for an orifice-type interrupting unit in which by the use of metallic orifices the presence of an arc length within the orifice region is prevented. As a result, the arc is drawn externally of the orifice region, and consequently there is avoided clogging of the orifice opening by ionized gas resulting from a high-amperage arc drawn within the orifice region. The present interrupting unit is particularly suitable for circuit interrupters interrupting very high-amperage currents, where otherwise there would be a tendency for clogging to occur within the orifice interior. By an application of the present invention, such clogging is prevented, and a highly effective cross-blast of the arcextinguishing gas is provided to quickly effect arc extinction and consequent circuit interruption. By incorporating a resistor, a simple and effective method of insertion is accomplished by using the metal orifice as described.

Although there has been illustrated and described specific structures, it is to be clearly understood that the same were merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art, without departing from the spirit and scope of the invention.

We claim as our invention:

1. A gas-blast circuit interrupter including means defining a source of high-pressure gas, means defining a blast entrance chamber composed of conducting material, blastvalve means interposed between said high-pressure source and said conducting blast entrance chamber, a relatively stationary contact supported by a rear conducting wall portion of said conducting blast entrance chamber, a forwardly-projecting generally cylindrically-s'naped gas-directing resistance orifice member wholly composed of resistance material and having a restricted orifice opening disposed adjacent its forward end, a conducting arcing ring lining the restricted orifice opening to which an arc may attach, a movable tubular vented contact movable with slight clearance through said restricted orifice opening and into the interior of the orifice member to make separable opening and closing engagement with the relatively stationary contact therein, the opening of the blast-valve means causing a blast of high-pressure gas to flow into said conducting blast entrance chamber to thereafter be guided by said resistance orifice member and into the interior of the vented movable tubular contact, said flow of gas causing the insertion into series circuit of the resistance of said orifice member and extinction of the main power are extending between the separable contacts, a residualcurrent are being established between said conducting arcing ring and the movable tubular vented contact, and the continuous exhausting of high-pressure gas out of said resistance orifice member causing a cross-blast extinguishing action to be exerted upon the residual-current are extending between the arcing ring at the orifice restriction and the movable tubular vented contact.

2. The combination according to claim 1, wherein the separation distance between the stationary contact and the orifice restriction is such as to cause extinction of the main power are prior to withdrawal of the movable tubular vented contact out of the orifice restriction.

3. The combination according to claim 1, wherein the resistance of the orifice member ranges from substantially 12 ohms to 200 ohms.

References tlited in the file of this patent UNTTED STATES PATENTS 2,275,872 Trencham et al Mar. 10, 1942 2,324,047 Van Ryan July 13, 1943 2,997,563 Smith et al Aug. 22, 1961 3,057,983 Yeckley et al Oct. 9, 1962 FOREIGN PATENTS 562,994 Great Britain July 25, 1944 743,787 Great Britain Jan. 25, 1956

Claims

1. A GAS-BLAST CIRCUIT INTERRUPTER INCLUDING MEANS DEFINING A SOURCE OF HIGH-PRESSURE GAS, MEANS DEFINING A BLAST ENTRANCE CHAMBER COMPOSED OF CONDUCTING MATERIAL, BLASTVALVE MEANS INTERPOSED BETWEEN SAID HIGH-PRESSURE SOURCE AND SAID CONDUCTING BLAST ENTRANCE CHAMBER, A RELATIVELY STATIONARY CONTACT SUPPORTED BY A REAR CONDUCTING WALL PORTION OF SAID CONDUCTING BLAST ENTRANCE CHAMBER, A FORWARDLY-PROJECTING GENERALLY CYLINDRICALLY-SHAPED GAS-DIRECTING RESISTANCE ORIFICE MEMBER WHOLLY COMPOSED OF RESISTANCE MATERIAL AND HAVING A RESTRICTED ORIFICE OPENING DISPOSED ADJACENT ITS FORWARD END, A CONDUCTING ARCING RING LINING THE RESTRICTED ORIFICE OPENING TO WHICH AN ARC MAY ATTACH, A MOVABLE TUBULAR VENTED CONTACT MOVABLE WITH SLIGHT CLEARANCE THROUGH SAID RESTRICTED ORIFICE OPENING AND INTO THE INTERIOR OF THE ORIFICE MEMBER TO MAKE SEPARABLE OPENING AND CLOSING ENGAGEMENT WITH THE RELATIVELY STATIONARY CONTACT THEREIN, THE OPENING OF THE BLAST-VALVE MEANS CAUSING A BLAST OF HIGH-PRESSURE GAS TO FLOW INTO SAID CONDUCTING BLAST ENTRANCE CHAMBER TO THEREAFTER BE GUIDED BY SAID RESISTANCE ORIFICE MEMBER AND INTO THE INTERIOR OF THE VENTED MOVABLE TUBULAR CONTACT, SAID FLOW OF GAS CAUSING THE INSERTION INTO SERIES CIRCUIT OF THE RESISTANCE OF SAID ORIFICE MEMBER AND EXTINCTION OF THE MAIN POWER ARC EXTENDING BETWEEN THE SEPARABLE CONTACTS, A RESIDUALCURRENT ARC BEING ESTABLISHED BETWEEN SAID CONDUCTING ARCING RING AND THE MOVABLE TUBULAR VENTED CONTACT, AND THE CONTINUOUS EXHAUSTING OF HIGH-PRESSURE GAS OUT OF SAID RESISTANCE ORIFICE MEMBER CAUSING A CROSS-BLAST EXTINGUISHING ACTION TO BE EXERTED UPON THE RESIDUAL-CURRENT ARC EXTENDING BETWEEN THE ARCING RING AT THE ORIFICE RESTRICTION AND THE MOVABLE TUBULAR VENTED CONTACT.