US2656491A - Integrator for line-sectionalizers - Google Patents

Description

OC- 20, 1953 J. M. WALLACE ET AL 2,656,491

INTEGRATOR FOR LINE-SECTIONALIZERS Filed July 2l, 1950 James M.Wo|lo ce and BWM ATTORNEY An drew W. Edwa rds.

Patented Oct. 20, 1953 INTEGRATOR FOR LINE SE CTIONALIZERS James M. Wallace and Andrew W. Edwards, East McKeesport, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application July 21, 1950, `Serial No. 175,272

8 Claims.

Our invention relates to improvements in linesectionalizing equipment for rural distributionlines, and it has particular relation to an improved double-armature self-resetting electromagnetic counter or integrator or a line-sectionalizer. Copending application, Serial No. 347,642, iiled on April 9, 1953, entitled Line Sectionalizers, is a division of this application.

These line-sectionalizers are inserted at intermediate points along a distribution-line, for cooperation Iwith a recloser which is connected at the power-input end of the line. The recloscr opens its line-contact, thus deenergizing the line, in response to overcurrents corresponding to, or exceeding, the minimum expectable fault-magnitude, after Which the recloser quickly recloses its line-contact, and if the fault has not cleared itself during the open-circuit condition of the line, the recloser immediately operates again, and keeps on alternately deenergizing and energizing the line, as long as the fault persists, until a predetermined number of operational counts have been made, usually four, after which the recloser locks its line-contact open and permanently deenergizes the protected distributionline. The line-sectionalizers subdivide the dis tribution-line into a number of sections. Each sectionalizer counts any rapidly repetitive overcurrent-conditions in its section, and at a count which is less than the recloser-count, the sec -K tionalizer opens its line-contact during a no-current period of the recloser.

The counting-mechanisms or integrators of both the recloser and the sectionalizers must be self-resetting, so that, if the overcurrent-conditions stop before the final count is made, the countingemechanism will slowly drift back to its initial positionl ready for a new count. The tWo common types of slowly acting resetting-means for such integrating devices are mechanical escapements and hydraulic dashpots. Mechanical escapements are critical to build, because of friction and corrosion problems. Hydraulic dashpots are simple, corrosion-resistant, and depend able, but they require the use of a liquid, which has usually meant that the entire circuit-interrupting device has been immersed in liquid.

Sectionalizing devices are preferably airinsulated, to save expense, because their circuit-interrupting duty is Zero, since the circuit is disconnected during a time when the current-flow has been interruptedl by an open condition of the recloser. One solution to the problem of provid`- ing liquid in a dashpot which operates an airyinsulated device has been to use some sort of (Cl. S17-178) 2 hermetically closed dashpot, having a flexible wall or bellows which moves to communicate the integrating intelligence to the outside of the sealed dashpot. However, the deflection of the flexible wall or bellows absorb-s considerable energy, and thus is often not desirable.

Our present invention relates to another soinm tion of the problem, wherein the dashpot is mov ably suspended inside of a magnetic circuit, y 'th means for moving the whole dashpot When ti time has come to indicate the completion ci the integrator-count. Thus, the dasiipot does not have exible walls, it remains stationary while the preliminary counting-operation is going on, and at the last count it finally moves a slight distance sufiioient to effect the desired trippingw operation.

Cui means for controlling the dashpot, in the manner just indicated, involve the use of a tubular dashpot-housing, having two normally spaced axially movable armatures therein, separated by a spring, and biased toward one end of the dashpot. The dashpot is mounted with some ireedom of axial movement between two separated polepiece plates of an electromagnet-structure which causes a magnetic ux to iow axially through a portion of the dashpot-tube; and the arrangen ment is such that quickly successive overcurrentn conditions, energizing the electromagnenstiuw ture, successively advance the armatures, until they can advance no further, after which the entire dashpot tube will be moved axially. Meanwhile, if the overcurrent-conditions cease before the required count has been made, the armatures will drift back slowly, within the dashpot, thus resetting themselves to their initial positions, ready for another count. In some cases, the dashpot uses any kind of a fluid-filling, either gas or liquid, not necessarily liquid, and when a gaseous filling is used (such as air), the tubular dashpot may need to be closed at only one end.

With the foregoing and other objects in View, our invention .consists in `the combinations, sysA tems, structures, parts, and methods ci and operation, hereinafter described and claim l, and illustrated in the accompanying drawing, wherein:

Figure 1 is a diagrammatic side-elevational view, with parts broken away, illustrating the application of one of our integrators or countingmechanisms to a line-sectionalizer having an airoperated disconnect-switch;

Fig. 2 is a diagrammatic sectional view showing the operation of the sealed integratoncapsuie; and

Fig. 3 is a diagrammatic View indicating the successive steps in the operation of the integrator-capsule.

The essential parts of the line-sectionalizer which is illustrated in Fig. 1 include an electromagnetic circuit 4 having a magnetizing-coil 5 having terminals A and 5B; an axially movable tubular integrator-capsule E; a toggle trippingmechanism i which is controlled by the movement of the integrator-capsule B; and an air-type disconnect-switch 8 which is tripped open by the tripping-mechanism '1, said switch 8 having terminals 8A and 8B.

The electromagnetic circuit 4 has two vertically spaced magnetizable pole-piece plates and |2, ybetween which the magnetizing coil 5 is disposed, for energizing the electromagnetic circuit and causing a magnetic ux to flow radially within said coil, between the upper and lower plates and i2. A uid-lled elongated tubular member or capsule El is vertically disposed for axial upand-down movement within the coil 5, and for this purpose the spaced magnetizable pole-piece plates il and |2 are provided with openings I3 which at least partially surround said tubular member '3, so that a magnetic ilux flows axially from pole-piece to pole-piece in an intermediate portion of said tubular member. The tubular member 6 extends both above the upper polepiece H and below the lower pole-piece |2, and the upper end of the tubular member 6 is biased upwardly by means of a compression-spring I4 which rests on the upper pole-piece The upwardly biased movement of the tubular member is limited by any suitable means, such as a ring or shoulder l5 carried by the tube underneath the upper pole-piece plate l.

The two pole-piece plates and |2 cause a magnetic flux to iiow vertically axially through only that portion of the tube S which is included between said plates. In order that this axial ux may enter inside of the tube, without being bypassed by the walls of the tube, the said tubular member 5 is preferably made of insulating material, as shown, or of other non-magnetizable material.

The tubular integrator-member 6 is preferably liquid-filled, in which case it is hermetically closed at both its top and bottom ends, as indicated at IB and Il in Fig. 2. Liquid filling is desirable because it permits the parts of the mechanism to be made with greater tolerances in the Various sliding iits, and in general it provides more easily attainable time-delay periods than air-operated time-delay devices. Theoretically, however', and perhaps in some practical cases, our invention can be used with either an air-lliug or a liquid-lling.

As shown in Fig. 2, the tubular member 6 contains two normally spaced armatures 2| and 22 therein, which are normally spaced, with a fixed or predetermined vertical spacing 23 therebetween, under the control of a vertical compression-spring 2d which is disposed between the two armatures.

Each of the armatures 2| and 22 is movable vertically axially within the tubular member 6. One-way-acting dashpot-means are associated with each of the armatures 2| and 22, whereby each armature may freely move vertically within the tube G, so far as the fluid-action is concerned, but each armature can drop back downwardly at only a slow fluid-restrained rate, under the inluence of gravity, which is the means for exerting a resetting biasing-torce on the armatures 2| and 22, tending to bias said armatures in their resetting direction toward the lower end of the tube 6.

In the illustrated embodiment of our invention, as shown in Fig. 2, each of the armatures 2| and 22 fits within the tubular member 6 with a ht which is sufficiently duid-tight to oppose rapid fluid-flow through said lit in the direction of the axis, the width of this t being exaggerated in the drawing, for clearness of illustration. Each of the illustrated armatures 2| and 22 also has a fluid-flow passage 25 extending therethrough in the direction of the axis, and each armature has a valve 26 therein for closing said passage, so as to resist rapid fluid-flow through said passage when the armature moves downwardly in its biased direction.

The initial biased position of the armatures 2| and 22 is such that the lower armature 22 extends materially below the axial-flux region of the tube 6, that is, materially below the lower pole-piece |2. Only a relatively small part of this lower armature 22, at the top end thereof, extends up into this axial-flux region.

Consequently, when the coil 5 of Fig. l is suiciently energized, the lower armature 22 of Fig. 2 will be drawn upwardly part way into said axialflux region. In other words, the suicient overcurrent-energization of coil 5 will draw the lower armature 22 upwardly away from its normal unattracted positie-n, in which it rests on the bottom end I'i of the tube under the influence of its gravitational resetting force. At the same time, when the coil 'I is sufficiently energized, the two armatures 2| and 22 will be attracted together, compressing the compressible spring 24 therebetween. In this position of the armatures, during the first overcurrent-condition in the magnetizing coil 5, the upper armature 2|, which had previously lain altogether within the axial-flux portion or the tube, with the top of this upper armature spaced well below the upper pole-piece plate il, is now advanced its first step upwardly, as indicated at 3| in Fig. 2, so that the top of this upper armature 2| comes at about the place of maximum attraction of the upper plate for this armature, as indicated by the construction line 3| in Fig. 2.

When the magnetizing coil is subsequently deenergized, the compression-spring 24 cannot rapidly thrust the lower armature 22 downwardly, because of the :duid-valve or dashpot action, and hence the compression-spring 24 advances the upper armature 2| upwardly, to its second advanced position, as indicated at 32 in Fig. 2, in which the upper end of this upper armature 2| is thrust slightly beyond or above the upper plate |i. At this time, the lower end of the lower armature 22 is still below the lower plate l2.

Consequently, if the magnetizing coil is immediately again adequately energized, the mag'- netic flux will draw the lower armature 22 further up into the axial-iiux region of the tube, again compressing the spring 24 between the armatures. The upper armature 2|, which now projects slightly beyond the upper end of the axial-ilux region, will also be attracted into said axial-flux region, that is, it will be attracted downwardly, but it cannot move quickly downwardly, because of its fluid-valve or dashpot action. Either at this step, or at some future step in the operation, in response to rapidly repeated overcurrent-conditions in the magnetizing coil, the lower armature 22 will be drawn up 5. so far that it is practically completely within the axial-flux region.

When the overcurrent-condition is now interrupted, the compression spring 24 will thrust the upper armature 2! still further upwardly out oi the axial-flux region, in the position indicated at 33 in Fig. 2.

If, now, the overcurrent-condtion immediately comes on again, the separated armatures 2! and 22 will be strongly attracted toward each other, while at the same time, the upwardly extending upper armature 2! will be strongly drawn downwardly into the axial-flux region between the two plates i! and l2. The result of this action is to draw the upper armature 2! downwardly, but it cannot move quickly downwary y within the tube 6, because of its Huid-valve or dashpot action, and hence, assuming that at least one end olf the tube 6 is closed, the whole tube will be drawn. downwardly, with the upper armature 2! compressing the tube-biasing spring le, and depressing the lower end il of the tube.

Fig. 3 diagrammaticaily indicates six positions if the armatures 2i and 22, and of the entire tube or capsule The iirst position is the normal unattracted position of the armatures 2! and 22, with respect to the capsule e and the upper and lower pole-pieces I! and I2. The second position shows the result of the rst overcurrent-energization. The third position shows the result or the first 11o-current period of the recloser (not shown), in which the line-current is interrupted by the recloser. The fourth position shows the result of the second overcurrent-energization, assumed to occur before the armatures have drifted any signicant distance back toward their biased initial position. This fourth position is assumed to be the next-to-the-last permissible overcurrent-count. The fifth position shows the result of the next current-zero condition. And the sixth position shows the depression of the enti-re capsule 6, during the third and last permissible overcurrent-energization oi the magnetizing coil 5 of Fig. l.

It will readily be understood that if the prescribed number of successive overcurrent-andundercurrent conditions do not follow each other in rapid succession, the armatures will reset themselves, ready for another count.

If the object of the integrator is to respond to a predetermined number of rapidly successive overcurrentconditions any responding-means can be used, which is responsive to the downward thrust of the integrator-capsule which occurs on the nal overcurrent-condition, as above described. i however (as is always the case in line-sectionalizers), the purpose of the integrator or counting-mechanism is to count a predetermined number of complete cycles oi overcurrent-and-underourrent conditions, then it is necessary to provide some means for responding to only the second half of the forward-and-baclrward movement of the capsule, when the last overcurrent comes on and goes on. It will be readily understood, of course, that the overcurrent-condition which drew the capsule downwardly, as previously described, will hold the capsule in its downwardly displaced position only as long as the overcurrent-condition lasts, after which the capsule will immediately return to its upwardly biased position, under the impulse of its lifting-.spring i4.

There are a number of means for making the integrator-response occur on the return-stroke of the displaced capsule E.

As shown in Figs. l and 2, the bottom end l1 of the capsule 6 has a depending pin 3!,which normally abuts against a trip-pin .l of the togglelinkage 'l in Fig. 1, so that, when the capsule 6 moves downward, it pushes the toggle-mechanism past its dead center, into the position in which it is biased toward its tripping-position, as by means of a biasing-spring 4| in Fig. l. However, the complete breakage of the toggle is prevented by means of a second pin t2 which abuts up against the side of the depending tripping-pin 3l of the integrator, and prevents the toggle from completely breaking until said tripping pin 3'! is withdrawn upwardly when the capsule v(i returns to its initial upwardly biased position at the end of the overcurrent-condition which caused the downward movement of the capsule. The advanced position of the tripping pins 3'! and d is indicated in Fig. 2 by means of construction-lines 43.

When the toggle-mechanism i is fully released, it pulls open a tripping-lever Mi which pushes open the blade 8 oi the disconnect-switch of the sectionalizer, thereby permitting said disconnectswitch to fall open the rest of the way, by gravity, for example.

The integrator-mechanism together with the toggle-mechanism 'i and the upper contacts 45 of the disconnect-switch, are conveniently mounted on a suitable insulator 45, while the bottom or hinged end of the disconnect-switch t is mounted on another insulator 4i'.

Ordinarily, the magnetizing coil 5 and the disconnect-switch 8 are connected in se des., as indicated in Fig. 1 by the connection 48 between the terminals 5B and 8A, so that the line-terminals of the entire line-sectionalizer are the terminals 5A and 8B, which are connected in series with the distribution-line which is being served by the sectionalizer.

While our integrator is primarily intended to be used in line-sectionalizers, and has been so described, it is also applicable to air-type circuitrcclosers or any other device which must ialce a similar count of current-surges.

While we have also described but a single illustrative form of embodiment of our invention, we wish it to be understood that we are not limited to the precise illustrated structures or combinations, and We desire that the appended claims shall be accorded the broadest construction ccnsistent with their language.

We claim as our invention:

l. A resetting electromagnetic counter comprising: a tubular member which is closed at at least one end; a magnetia'ing coil for causing a magnetic flux to flow axially in an intermediate portion of said tubular member; means for mounting said tubular member so that it has some freedom of axial movement with respect to the axial-flux region of the magnetic flux produced by said coil; two normally spaced armatures which are axially movable within said tubular member; a compressible spring between the two armatures; biasing-means tending to move both armatures in the saine axial direction within said tubular member for resetting the counter; biasing-means tending to move the tubular member in the `opposite direction; dashpotmeans associated with each armature within said tubular member including a movable dasm pot element operatively connected 'with the armature ior resisting rapid axial movement of that armature in the biased direction; the initial .biased position of the armatures being such that a nrst one of the armatures extends materially beyond the axial-ux region in its biased direction, whereby, when said coil is sufficiently energized, that armature will be drawn partway into said axial-iiux region in an advancing direction opposite to said biased direction, while, at the same time, the two armatures will be attracted together, compressing said compressible spring; and whereby, when the coil is thereafter deenergized, said compressible spring will advance the second armature while said rst-mentioned armature temporarily remains substantially stationary; the proportions oi the parts being such that a quickly following second energization of the coil will draw said first-mentioned armature iurther into said axial-ilux region in said advancing direction, followed, on another quickly following deenergization of the coil, by a second advance oi the second armature; the nnal movement ci the armatures being such that, upon the last deenergization, of a predetermined succession of rapidly repeated energizations and deenergizations or the coil, the second armature will be in an advanced position extending so far beyond the axial-flux region, and the first armature will be so far within said axial-lux region, that a quiclrly following reenergization of the coil will force the tubular member in the direction toward which the armatures are biased, against the bias which is applicable to said tubular member.

2. The invention as dened in claim l, characterized by said tubular member being a liquidlled tubular capsule, hermetically closed at both ends.

3. A esetting electromagnetic counter comprising: a tubular member which is closed at at least one end; a magnetizing coil ior causing a magnetic iux to now axially in an intermediate portion of said tubular member; means for mounting said tubular member so that it has some freedom of axial movement with respect to the axial-flux region of the magnetic flux produced by said coil; two normally spaced armatures within said tubular member, each of said armatures tting within said tubular member with a fit which is sufciently fluid-tight to oppose rapid fiuid-ow through said nt in the direction of the axis; a compressible spring between the two armatures; biasing-means tending to move both armatures in the same axial direction within said tubular member for resetting the counter; biasing-means tending to move the tubular member in the opposite direction; each of said armatures having a fluid-flow passage extending therethrough in the direction of the axis, and each having a valve for closing said passage so as to resist rapid iiuid-low through said passage when that armature moves in the biased direction; the initial biased position of the armatures being such that a iirst one of the armatures extends materially beyond the axialflux region in its biased direction, whereby, when said coil is suiliciently energized, that armature will be drawn partway into said axial-flux region in an advancing direction opposite to said biased direction, while, at the same time, the two armatures will be attracted together, compressing said compressible spring; and whereby, when the coil is thereafter deenergized, said oompressible spring will advance the second armature while said first-mentioned armature temporarily remains substantially stationary; the proportions of the parts being such that a quickly following second energization of the coil will draw said first-mentioned armature further into said axialiiux region in said advancing direction, followed, on another quickly following deenergization of the coil, by a second advance of the second armature; the nal movement of the armatures being such that, upon the last deenergization, of a predetermined succession of rapidly repeated energizations and deenergizations of the coil, the second armature will be in an advanced position extending so far beyond the axial-flux region, and the iirst armature will be so far within said axial-flux region, that a quickly following reenergization of the coil will force the tubular member in the direction toward which the armatures are biased, against the bias which is applicable to said tubular member.

4. The invention as dened in claim 3, characterized by said tubular member being a liquidlled tubular capsule, hermetically closed at both ends.

5. A resetting electromagnetic counter comprising: an electromagnetic circuit having two spaced magnetizable pole-piece plates, and a coil for energizing said electromagnetic circuit; a tubular member disposed in operative relation to said electromagnetic circuit, with each of said spaced magnetizable pole-piece plates having an opening which at least partially surrounds said tubular member, so that a magnetic flux flows axially from pole-piece t0 pole-piece in an intermediate portion of said tubular member; means for mounting said tubular member so that it has some freedom of axial movement within said openings in the pole-piece plates; two normally spaced armatures which are axially movable within said tubular member; a compressible spring between the two armatures; biasingmeans tending to move both armatures in the same axial direction within said tubular member for resetting the counter; biasing-means tending to move the tubular member in the opposite direction; dashpot-means associated with each armature within said tubular member including a movable dashpot element connected to move with the armature for resisting rapid axial movement of that armature in its biased direction; the initial biased position of the armatures being such that a iirst one of the armatures extends materially beyond the axial-flux region in said biased direction, whereby, when said coil is sufficiently energized, that armature will be drawn partway into said axial-iiux region in an advancing direction opposite to the biased direction, while, at the same time, the two armatures will be attracted together, compressing said compressible spring; and whereby, when the coil is thereafter deenergized, said compressible spring will advance the second armature while said inst-mentioned armature temporarily remains substantially stationary; the proportions of the parts being such that a quickly following second energization of the coil will draw said first-mentioned armature further into said axiallux region in said advancing direction, followed, on another quickly following deenergization of the coil, by a second advance of the second armature; the final movement of the armatures being such that, upon the last deenergization, of a predetermined succession of rapidly repeated energizations and deenergizations of the coil, the second armature will be in an advanced position extending so far beyond the aXial-ux region, and the first armature will be so far within said axial-flux region, that a quickly following reenergization of the coil will force the tubular member in the direction toward which the armatures are biased, against the bias which is applicable to said tubular member.

6. The invention as dened in claim 5, characterized by said tubular member being a liquidlled tubular capsule, hermetically closed at both ends.

7. A resetting electromagnetic counter comprising: an electromagnetic circuit having two spaced magnetizable pole-piece plates, and a coil for energizing said electromagnetic circuit; a tubular member disposed in operative relation to said electromagnetic circuit, with each of said spaced magnetizable pole-piece plates having an opening which at least partially surrounds said tubular member, so that a magnetic iiux flows axially from pole-piece to pole-piece in an intermediate portion of said tubular member; means for mounting said tubular member so that it has some freedom of axial movement within said openings in the pole-piece plates; two normally spaced armatures within said tubular member, each of said armatures tting within said tubular member with a .t which is sufficiently fluid-tight to oppose rapid huid-flow through said t in the direction of the axis; a compressible spring between the two armatures; biasing means tending to move both armatures in the same axial direction within said tubular member for resetting the counter; biasing-means tending to move the tubular member in the opposite direction; each of said armatures having a Huid-flow passage extending therethrough in the direction of the axis, and each having a valve for closing said passage so as to resist rapid iiuidflow through said passage when that armature moves in its biased direction; the initial biased position of the armatures being such that a rst cre of the armatures extends materially beyond the aXial-ilux region in said biased direction, whereby, when said coil is suiiiciently energized, that armature will be drawn partway into said axial-ux region in an advancing direction opposite to the biased direction, while, at the same time, the two armatures will be attracted together, compressing said compressible spring; and whereby, when the coil is thereafter deenergized, said compressible spring will advance the second armature while said iirst-mentioned armature temporarily remains substantially stationary; the proportions of the parts being such that a quickly following second energization of the coil will draw said first-mentioned armature further into said axial-flux region in said advancing direction, followed, on another quickly following deenergization of the coil, by a second advance of the second armature; the iinal movement of the armatures being such that, upon the last deenergization, of a predetermined succession of rapidly repeated energizations and deenergizations of the coil, the second armature will be in an advanced position extending so far beyond the axial-flux region, and the rst armature will be so far within said axial-flux region, that a quickly following reenergization of the coil will force the tubular member in the direction toward which the armatures are biased, against the bias which is applicable to said tubular member.

8. The invention as defined in claim 7, characterized by said tubular member being a liquidfilled tubular capsule, hermetically closed at both ends.

JAMES M. WALLACE. ANDREW W. EDWARDS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 254,743 Waterhouse Mar. 7, 1882 1,737,649 Edsall Dec. 3, 1929 1,868,256 Rippl July 19, 1932 2,337,713 Garlington Dec. 28, 1943 2,451,692 Lindstrom Oct. 19, 1948 2,523,984 Edwards Sept. 26, 1950

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