EP0559552B1 - Load break switch for high nominal intensity and its use in a cell and in a medium voltage installation - Google Patents

Abstract

Multipole load break switch for high nominal intensity comprising, for each pole, an insulating bushing enclosing a vacuum bulb (14) and two conductive blades (7, 8) for the flow of the permanent current, the bushings being integral with a common metallic supporting profile (4) placed at earth potential and shrouding a common shaft for operating the vacuum bulbs, actuated by a mechanism contained in a box integral with the profile, the elements for connection of the bushings of the poles being arranged so that, when the profile pivots, the current is switched from the blades (7, 8) to the vacuum bulbs (14). The invention applies to the construction of medium voltage cells and installations with high nominal intensity. <IMAGE>

Description

The present invention relates to a self-disconnecting circuit breaker according to the preamble of claim 1 usable in particular for circuits or lines with high nominal current, for example 3150 amps and more. The present invention also relates to a cell comprising such a self-disconnecting circuit breaker and to a station comprising such a cell.

An electrical disconnect circuit breaker is an electrical device having a circuit breaker breaking capacity and which, when in the open position, has between its terminals a dielectric strength between input and output equal to or greater than that required for the disconnectors. Such a device can therefore replace three switchgear functions, which is particularly advantageous for the operator, both because of the savings made in investment (lower cost, smaller footprint) than by the savings in maintenance at during operation.

We know, from French Patent No. 1,533,266, an armored cell comprising for each phase a rotary cut-off device, the rotation of the device around an axis located in a vertical plane of the cell ensuring its own cutting.

Such a device could not be built industrially because of the considerable length and the weight of the cut-off devices of the sealed type with non-flammable fluid envisaged, in particular the sulfur hexafluoride (SF6) circuit breakers. Another handicap results from the length of travel of the SF6 circuit-breakers, which penalizes the type of device mentioned above by the excessive length which it would be necessary to give them.

A first object of the invention is to provide a multi-pole self-disconnecting circuit breaker of low weight and compact in all its dimensions, therefore easily accommodable in a cell and easily maneuverable without requiring great maneuvering energy.

• ils obligent à mettre en oeuvre beaucoup de cuivre, ce qui les rend chers,
• ils sont toujours le siège de pertes Joule donc d'échauffements souvent difficiles à limiter,
• les sections minimales des conducteurs sont peu compatibles avec les technologies de coupure employées, par exemple:
  • 1) dans les appareils à faible volume d'huile, l'augmentation du diamètre de la tige mobile nuit à l'effet de soufflage de l'arc dans le pôt de coupure,
  • 2) dans la technologie de coupure à autosoufflage dans le SF6, les constructeurs ont dû pour la même raison en venir à l'emploi de contacts parallèles souvent difficiles à coordonner avec les contacts de coupure,
  • 3) dans les appareils à vide, l'agencement en général très élaboré des électrodes de contact (diffusion et centrage des arcs élémentaires) est en général générateur de pertes Joule élevées que l'on doit souvent compenser avec l'utilisation de radiateurs relativement importants destinés à faciliter le refroidissement des ampoules à vide lors du passage du courant nominal.

In a full range of medium-voltage circuit breakers, the devices with high nominal current (3150 amps and more), essential because they very often equip the incoming and coupling cells, generally pose problems to their manufacturers for the following reasons: after:

• they force a lot of copper, which makes them expensive,
• they are always the seat of Joule losses, therefore of heatings which are often difficult to limit,
• the minimum sections of the conductors are not very compatible with the cutting technologies used, for example:
  • 1) in devices with low oil volume, the increase in the diameter of the movable rod harms the blowing effect of the arc in the cutoff,
  • 2) in SF6 self-blowing breaking technology, manufacturers had for the same reason to come to the use of parallel contacts often difficult to coordinate with the breaking contacts,
  • 3) in vacuum devices, the generally very elaborate arrangement of contact electrodes (diffusion and centering of elementary arcs) generally generates high Joule losses which often have to be compensated with the use of relatively large radiators intended to facilitate the cooling of the vacuum interrupters during the passage of the nominal current.

It should also be noted that these devices, which are always difficult to produce, are always the subject of much lower series than devices of low nominal intensity.

It is known that in order to overcome the aforementioned difficulties in producing high-caliber devices, certain manufacturers have arrived at SF6 circuit breakers to dissociate the breaking functions. and disconnection, by making the breaking by a circuit breaker chamber and the disconnection by an associated disconnector crossed by the nominal current.

• à l'ouverture: ouverture du sectionneur, puis ouverture du circuit par le disjoncteur,
• à la fermeture: fermeture du disjoncteur, puis fermeture du sectionneur.

The coordinated movements of the two devices are generally defined as follows:

• on opening: opening of the disconnector, then opening of the circuit by the circuit breaker,
• on closing: closing of the circuit breaker, then closing of the disconnector.

These movements are ensured by the same control box whose kinematics, arranged accordingly, is complicated and includes numerous joints.

• faible encombrement global,
• dispositions très aérées autorisant une excellente ventilation en cellule,
• longueur minimale de métal conducteur (peu de cuivre),
• nombre réduit de contacts série, donc limitation des pertes Joule,
• cinématique de commande simple, comportant peu d'articulations.

Another object of the invention is to provide a single device, usable for the passage of a high nominal current, ensuring the breaking and cutting functions and having the following qualities:

• small overall size,
• very airy arrangements allowing excellent ventilation in the cell,
• minimum length of conductive metal (little copper),
• reduced number of serial contacts, thus limiting Joule losses,
• simple control kinematics, with few articulations.

Another object of the invention is to provide a cell and a medium-voltage substation equipped with the above-mentioned self-isolating circuit breaker.

The subject of the present invention is a multipole self-disconnecting circuit breaker comprising for each pole a double insulating bushing surrounding a vacuum interrupter and comprising at a first end a first connection element connected to a first terminal of the ampoule and intended to be connected electrically to an incoming conductor, and at a second end a second connection element connected to the other terminal of the bulb and intended to be connected electrically to a feeder conductor, characterized in that each crossing further comprises at least two metal blades passing right through it and opening out to form external sockets intended to be connected respectively to said feeder conductor and to said audit incoming conductor, the bushings being fixed to the same metal section along and sheltered from which is placed a common operating shaft for the bulbs and actuated by a control for operating the bulbs contained in a box integral with the section, the latter capable of being actuated in rotation, the aforementioned plugs and connection elements of the bushing being arranged so that the rotation of the profile first causes the switching of the current passing through the said blades in the vacuum interrupter, then the cutting of the apparatus .

In a particular embodiment, the insulating passage of each pole comprises a first cavity in which is housed the vacuum bulb, said bulb comprising an insulating envelope closed by first and second metal flanges, the first metal flange being externally connected to one of said connection elements and internally to a fixed contact of the vacuum interrupter, said second flange being leaktightly traversed by a movable metal rod carrying a second movable contact of the vacuum interrupter, the crossing insulator each comprising a second cavity communicating with the first cavity and in which is disposed a metal tube mechanically connected to the vacuum interrupter and electrically connected to said movable metal rod, said tube containing a control rod connected to said movable metal rod,! insulating bushings of each pole being fixed to said metal profile, the ti control of each pole being mechanically connected to said shaft by means of a lever articulated on an end piece integral with the metal tube, of an insulating arm articulated by a first end to said lever and by a second end to a connecting rod wedged on said shaft, said end piece being mechanically and electrically connected to said metal tube and carrying said second connection element.

The first cavity has internal grooves parallel to the axis of the passage, defining with the external wall of the vacuum interrupter ventilation channels, the air circulating in the metal tube and penetrating into said channels through holes in said tube.

Alternatively, the vacuum interrupter is placed in an insulating cylindrical cage, for example made of resin, placed in said first cavity.

In the latter case, said cage has grooves parallel to its axis, defining with the wall of the vacuum interrupter ventilation channels, the air circulating in the metal tube and penetrating into said channels through holes in said tube.

The dielectric strength between said metal tube and the wall of said second cavity is ensured by a sheath of compressible insulating material slid over said metal tube and engaged in said second cavity, the mounting being facilitated by the use of an insulating grease.

Preferably, said sheath is made of latex.

Advantageously, the kinematic chain between said control rod and said control shaft comprises a spring play adjustment mechanism.

Alternatively, the end of the control rod comprises a tubular end portion in which engages said movable rod, said movable rod comprising a lumen in which is engaged a first pin passing through said control rod, a spring s' pressing against a first support washer in contact with said end of the control rod, and against a second support washer engaged in the mobile rod and held by a second pin passing through the mobile rod.

In a particular embodiment, the mechanical connection of said metal tube with the vacuum interrupter and the electrical connection of said metal tube with said movable contact rod is ensured by means of a sleeve fixed to said second flange, of a ring secured to said sleeve and to said tube, and to an accordion or socket type contact disposed inside said ring and surrounding said rod.

Said end piece comprises two half-collars tightened on said metal tube and in abutment on the end of the insulating bushing.

The half-collars comprise lugs cooperating with cells made in the insulating bushing to immobilize said metal tube in rotation.

Said sheath is blocked by a circlip tightened on said metal tube.

The outer surface of the insulating bushing is metallized in the area adjacent to the support profile.

The crossing comprises, in the vicinity of the fillet connecting the two cavities, a metal grid inserted in the molding and set to the potential of said metal tube.

The invention also relates to a medium-voltage cell, characterized in that it comprises at least one self-disconnecting circuit breaker of the aforementioned type.

In a particular embodiment, the cell comprises a self-disconnecting circuit breaker of the aforementioned type, the latter being placed in a sliding drawer in a box comprising support insulators for a busbar and support insulators for a cable outlet, the metal section supporting the self-isolating circuit breaker being articulated on two opposite faces of said drawer, the self-isolating circuit breaker being able, in the sectioned position, to take place entirely in the drawer which can be at least partially but largely extracted from the box.

The box has a first, fixed flap, separating the space containing the bars from the space in the drawer.

The box has a second, movable flap, occupying a position above the first flap when the circuit breaker is in service and coming, when the circuit breaker is in the cut position, occupy a place where it completely prevents, with the first shutter access to the bar space from the drawer space.

The movement of the second flap is ensured by a disc driven in rotation by the rotation of the profile and actuating at least one set of connecting rods connected to said second drawer which slides in slides fixed to the box.

The disc comprises a notch cooperating with a latch to immobilize the disc when the drawer is extracted, the latch being unlocked by action of the drawer when the latter is replaced.

The drawer has a shutter driven in rotation by the rotation of the circuit breaker-auto-selector when passing from the cut-off position of the disconnection to the tripped position and putting the poles to earth when the self-disconnector circuit breaker is in the cut position.

The metal profile is rotated by a gear motor fixed to the drawer and cooperating with a pinion secured to the profile.

The invention also relates to a medium-voltage substation comprising a cell of the aforementioned type and at least one cell comprising a self-disconnecting circuit breaker of the aforementioned type associated with a busbar ascent compartment.

• la figure 1 est une vue en perspective d'un disjoncteur auto-sectionneur triphasé selon l'invention,
• la figure 2 est une vue en coupe axiale d'un pôle de disjoncteur auto-sectionneur selon l'invention,
• la figure 3 est une vue en coupe axiale du même pôle, à 90 degrés de la précédente.
• la figure 4 est une vue en coupe selon la ligne IV-IV de la figure 2,
• la figure 5 est une vue en coupe selon la ligne V-V de la figure 3,
• la figure 6 est une vue en coupe axiale de la partie supérieure d'un pôle selon une variante de réalisation permettant de loger une ampoule à vide de petites dimensions,
• la figure 7 est une vue en élévation en coupe axiale d'une partie d'un pôle montrant les dispositions pour relier mécaniquement et électriquement le tube métallique et l'ampoule à vide,
• la figure 8 est une vue en élévation en coupe d'un dispositif de rattrapage de jeux pour la commande des contacts de l'ampoule,
• la figure 9 est une vue en élévation d'un disjoncteur auto-sectionneur selon l'invention, équipé de son tiroir et placé dans un caisson fixé à une charpente, le disjoncteur auto-sectionneur étant représenté avec les fonctions sectionneur et disjoncteur enclenchées,
• la figure 10 est une vue analogue à la précédente, le disjoncteur auto-sectionneur étant représenté avec ses fonctions sectionneur et disjoncteur déclenchées,
• la figure 11 est une vue en perspective de l'un des borniers coopérant avec le pôle du disjoncteur auto-sectionneur de l'invention,
• la figure 12 représente schématiquement une cellule équipé du disjoncteur auto-sectionneur de l'invention, la cellule étant montrée avec le tiroir ouvert,
• la figure 13 représente la même cellule, avec le tiroir fermé,
• la figure 14 représente le mécanisme de manoeuvre de sectionnement du disjoncteur auto-sectionneur de l'invention,
• la figure 15 est une vue de côté du volet de protection coulissant et de son mécanisme de manoeuvre,
• la figure 16 est une vue de dessus du même mécanisme,
• la figure 17 est un schéma expliquant le mécanisme de manoeuvre de la partie disjoncteur du disjoncteur auto-sectionneur de l'invention,
• la figure 18 représente schématiquement un poste réalisé au moyen de plusieurs disjoncteurs auto-sectionneurs.

The invention is clarified by the following description of a detailed embodiment of the self-disconnecting circuit breaker of the invention, as well as of a medium-voltage cell by applying it, with reference to the attached drawing in which:

• FIG. 1 is a perspective view of a three-phase self-disconnecting circuit breaker according to the invention,
• FIG. 2 is a view in axial section of a pole of a self-disconnecting circuit breaker according to the invention,
• Figure 3 is an axial sectional view of the same pole, 90 degrees from the previous one.
• FIG. 4 is a sectional view along the line IV-IV of FIG. 2,
• FIG. 5 is a sectional view along the line VV of FIG. 3,
• FIG. 6 is a view in axial section of the upper part of a pole according to an alternative embodiment making it possible to house a vacuum bulb of small dimensions,
• FIG. 7 is an elevational view in axial section of part of a pole showing the arrangements for mechanically and electrically connecting the metal tube and the vacuum interrupter,
• FIG. 8 is a sectional elevation view of a clearance take-up device for controlling the contacts of the bulb,
• FIG. 9 is an elevation view of a self-disconnecting circuit breaker according to the invention, equipped with its drawer and placed in a box fixed to a frame, the self-disconnecting circuit breaker being shown with the disconnector and circuit breaker functions engaged,
• FIG. 10 is a view similar to the previous one, the self-disconnecting circuit breaker being shown with its disconnector and circuit breaker functions tripped,
• FIG. 11 is a perspective view of one of the terminal blocks cooperating with the pole of the self-disconnecting circuit breaker of the invention,
• FIG. 12 schematically represents a cell fitted with the self-disconnecting circuit breaker of the invention, the cell being shown with the drawer open,
• FIG. 13 represents the same cell, with the drawer closed,
• FIG. 14 shows the mechanism for operating the sectioning of the self-disconnecting circuit breaker of the invention,
• FIG. 15 is a side view of the sliding protective flap and its operating mechanism,
• FIG. 16 is a top view of the same mechanism,
• FIG. 17 is a diagram explaining the operating mechanism of the circuit breaker part of the self-isolating circuit breaker of the invention,
• FIG. 18 schematically represents a station produced by means of several self-disconnecting circuit breakers.

In Figure 1, the poles of the self-disconnecting circuit breaker of the invention are referenced 1, 2 and 3; they are fixed to a common metal profile 4, preferably at right angles, along and sheltered from which is placed a control shaft 38 of the poles. Reference 29 designates the pole fixing collar on the profile 4.

Profile 4 is at ground potential; as will be seen below, the profile can turn on itself around its longitudinal direction to ensure the switching current function and cutting the device; the profile 4 is integral with a control box 5 for the circuit breaker function of the device, inside which the shaft 38 penetrates.

The assembly constituted by the profile and the poles is well balanced, so that the above-mentioned sectioning operation requires only a low energy.

Figure 2 is an axial sectional view of a pole, for example the pole 1. Figure 3 is an axial sectional view of the same pole, 90 ° from the previous one.

The pole includes an insulating bushing 10, made of resin or elastomer. If necessary, the bushing can be fitted with fins of the attached type or molded inlets.

The bushing 10 is a cylindrical volume with a rectangular cross section, with rounded corners for dielectric reasons.

Two copper strips 7 and 8 parallel to each other and to the axis of the crossing are arranged inside the latter; the blades are placed within the bushing during the molding thereof. The blades 7 and 8 extend outside the bushing to form electrical outlets at each end of the bushing. These sockets are referenced 7A, 7B, 8A and 8B. They cooperate with complementary sockets described below and are used to convey the permanent current which, as already explained, is of high intensity (3150 amps and more for example).

The passage comprises, at the upper part of the drawing, an axial cylindrical housing receiving a vacuum interrupter 14 shown diagrammatically.

The vacuum interrupter comprises an insulating envelope 15, preferably made of ceramic, and two metal end plates or flanges 16 and 17. On the plate 16 is fixed, inside the ampoule, a metal rod 18 carrying a fixed contact 19; a connection element 20A, such as a jaw, is fixed to the plate 16, outside the envelope.

The vacuum interrupter comprises a movable contact 21 carried by a metal rod 22 sliding in leaktight manner through the plate 17 thanks to a sealing bellows 23.

The interior surface of the housing of the vacuum interrupter is provided with grooves 12 parallel to the axis of the passage and serving as ventilation channels, as will be explained below. It will be noted that the diameter and the depth of the vacuum bulb housing are chosen for a given type of vacuum bulb; if you want to accommodate a bulb of smaller dimensions, you will interpose, as shown in Figure 6, between the inner wall of the housing and the vacuum bulb 14, a cylindrical cage 13 of insulating material such as resin, provided of external grooves 13A defining with the lateral surface of the vacuum interrupter ventilation channels.

Returning to FIGS. 2 and 3, it can be seen that the bushing comprises a second frustoconical housing in communication with the housing of the vacuum interrupter. The volume delimited by this second housing is therefore conical, its section decreasing when moving from the housing of the bulb.

The second housing contains a metal tube 25, preferably made of copper, secured to the vacuum interrupter as will be shown with reference to FIG. 7, and in electrical contact with the movable rod 22 of the vacuum interrupter. The tube 25 is used to convey the current between the vacuum interrupter and a part 26, described in detail with reference to FIG. 5 and carrying a connection element 20B, for example a jaw.

The dielectric strength between the bushing 10 and the metal tube 25 is ensured by means of a sheath 27, of insulating material such as latex, and having a tubular shape with a cylindrical inner section and a conical outer surface complementary to the surface of the second home. During assembly, this sheath is slid around the metal tube 25, slipping being facilitated by the use of an insulating grease, for example based on silicone. Then the outer surface of the sheath is coated with the same grease and engaged in the second housing, applying pressure so as to ensure the elimination of air. Maintaining the sheath in compression is ensured by means of a stop means such as a circlip 28 engaged in a groove in the tube 25.

The pole is placed in abutment on the metal profile 4, thanks to a transverse groove 10A of the bushing, coming from molding.

The opening or closing operation of the vacuum interrupter is ensured by means of a rod 30, for example metallic, fixed for example by screwing to the rod 22. This rod is articulated at 31 to a return lever 32 itself articulated at 33 on part 26. The end of the lever is articulated at 34 at a first end of an insulating rod 35 whose second end is articulated at 36 at a first end of a connecting rod 37 whose second end is wedged on the control shaft 38 placed along the profile 4 .

The copper tube 25 carries, in the vicinity of the plate 17, holes 25A whose role is explained now.

When the self-disconnecting circuit breaker of the invention is closed, the nominal current mainly passes through the conductors 7 and 8; only a fraction of the current flows through the vacuum interrupter. To interrupt the current in the circuit breaker, either for a normal operating operation or because of a fault, the device is tilted by rotation of the profile, which causes the separation of the contacts 7A, 7B , 8A, 8B, then the vacuum interrupter is opened by the rotation of the shaft 38 causing, by the play of the various levers, the displacement of the rod 30. The entire current flows through the vacuum interrupter for a few milliseconds before the separation of contacts 19 and 21; the bulb is cooled by an air circulation which engages in the part 26, passes through the annular space between the operating rod 30 and the tube 25, passes through the holes 25A and engages in the grooves 12 of the first housing (or the grooves 13A in the case of the alternative embodiment of Figure 6). This bulb ventilation circuit is of primary importance because it eliminates the risks of pollution and condensation.

Reference will be made to FIG. 7 which shows how the metal tube 25 is mechanically fixed to the vacuum interrupter 14 and how the current can pass from the movable rod 22 to the tube 25.

Vacuum ampoules usually include a metal cover welded to the plate 17 and which contains a bearing for the movable rod 22. For the purposes of the invention, the cover is modified and transformed into a sleeve 15A internally threaded to which a metal ring 15B can be screwed. The tube 25 is engaged inside this ring and secured to the ring by brazing or screwing. The ring and the tube then define a shoulder against which an accordion type contact or a contact socket 15C rests.

The shape and role of the part 26 are specified with reference to FIGS. 3 and 5. It can be seen that the part 26 comprises two half-collars 41 and 42 which can be tightened by means of screws 43, 44. These half-collars enclose the end of the conductive tube 25, which protrudes from the bushing 10, with a contact pressure sufficient to ensure the passage of current. The half-collars, abutting against the end of the bushing 10, thus ensure the immobilization in axial translation of the tube 25 and the vacuum interrupter 14 which is integral therewith.

Lugs 45 carried by the half-collars cooperate with cells coming from molding at the end of the bushing 10 to immobilize the tube 25 and, consequently, the vacuum interrupter 14, in rotation.

A plate 46, secured to the half-collars for example by means of screws 47, serves to support the connection element 20B.

The outer surface of the bushing 10, in line with the section 4, is metallized and brought to earth potential.

Examination of FIGS. 2 and 3 shows the presence, between the flange 17 and the passage portion 10C connecting the two housings, of a volume filled with air. Without special precautions, this volume would be subject to a strong potential gradient which could lead to partial discharges which in the long run can be destructive. To avoid this drawback, the bushing comprises, in line with the aforementioned volume, a metal mesh 51A inserted during the molding of the bushing, and which is set to the potential of the metal tube 25. In this way, the potential differences are applied to the only insulating parts.

The operating rod 30 may comprise a play take-up member comprising a cage provided with a spring 53; this play take-up member can also, as a variant, be arranged at any location of the kinematic chain connecting the rod 22 and the control shaft 38.

This cage can in certain cases be too bulky, it is possible to replace it with the device described below with reference to FIG. 8.

At least the end of the control rod 30 has a tubular portion 30A in which engages the end of the movable rod 22 of the bulb. The movable metal rod 22 includes a light 22A in which is engaged a first pin 22B passing through the rod 30. A spring 22C is disposed between a first support washer 22D in contact with the end of the tubular part 30A, and a second washer 22E engaged in the rod 22 and held by a second pin 22F passing through the rod 22. In the closed position of the bulb contacts, the rod 30 compresses the spring 22C which transmits the force to the movable rod 22 without play. It will be noted that the play take-up assembly is guided in the conductive tube 25 by the washers 22D and 22E supporting the spring. The washers have holes or notches at their periphery to allow the passage of the air for cooling the bulb.

It has been indicated that only the end of the control rod 30 is made in tubular form; alternatively, the control rod can be a tube over its entire length.

The control shaft 38 is fixed to the metal section 4 by known means not shown, so as to leave it free to rotate. The shaft can be protected more completely by means of a not shown angle profile, for example plastic, clipped onto the metal profile 4 so as to define a hollow beam and thus protect the shaft 38 from the dust.

Figures 9 to 12 illustrate the mounting of the self-disconnecting circuit breaker of the invention for the production of a medium voltage cell.

In Figures 9 and 10, there is a metal frame 55 seen in section; this frame is brought to earth potential by conventional means not shown; to this frame is fixed, by all means not shown, a box 55A containing the self-isolating circuit breaker of the invention, as well as various elements described below: the box first contains a drawer 56 sliding on slides; the drawer 56 has two opposite faces 56A and 56B (see FIG. 12) on which the ends of the metal section 4 are mounted in rotation. It will be recalled that this profile can rotate on itself and that it is integral with the control box 5 shown in dashed lines in FIGS. 10 and 11.

The box carries at its upper part insulators 57 serving to support terminals 58 connected to the electrical bars 59 of the station. The frame is surmounted by the bar compartment 60.

The box carries a first fixed flap 61 which prevents access to the left part of the bar compartment from the front face of the cell. The box carries slides 61A carrying a flap 61B which, when the circuit breaker is in normal service, remains on the left of the figure (figure 9) and which, when the circuit breaker is in the sectioned position (figure 10) , automatically moves to the right of the figure to prevent access to the right part of the bar compartment from the front of the cubicle.

The drawer comprises a pivoting automatic shutter 62 which is returned to position by a spring 63; in normal service (figure 9), this flap separates the busbar compartment from the cable compartment; during a sectioning maneuver, it ensures the earth potential of the device coming and remaining in contact with the contact 8A (Figure 10).

At the lower part of the box, there is a cable compartment, where each starting cable 65 is connected to a terminal 66 carried by a support insulator 67 which can also serve as a voltage detector, the latter being detected by means of indicator lamps 68 placed at the base of the support insulator 67.

Terminal 66 (Figure 11) comprises two trapezoidal blades 66A and 66B intended to cooperate with the blades 7B and 8B of the pole, and an elongated blade 66C intended to cooperate with the connection element 20B; the blades 66A and 66B carry contact fingers 66D between which the blades 7B and 8B engage. The trapezoidal shapes facilitate a gradual entry into service of the contacts, therefore a better distribution of forces.

Terminal 58 has the same elements as terminal 66, referenced 58A, 58B, 58C and 58D to cooperate with the blades 7A and 8A as well as the connection element 20A.

An earthing switch 70 completes the equipment of the cell.

• en fonctionnement normal, le disjoncteur auto-sectionneur est dans la configuration représentée dans la figure 9. Le courant circule entre le câble 65 et la barre 59 en empruntant de préférence les lames 7 et 8, de sorte qu'un courant relativement faible traverse l'ampoule à vide.
• si on souhaite interrompre le courant, soit pour une manoeuvre normale d'exploitation, soit sur défaut, un ordre est donné à l'organe de manoeuvre du profilé 4 qui tourne sur lui-même dans le sens de la flèche F1 de la figure 9; cette rotation entraîne la séparation des éléments de connexion 20A et 20B d'avec les doigts 58D et 66D. Le courant traversant les lames 7 et 8 est commuté dans l'ampoule à vide; un ordre est donné alors au mécanisme de commande de l'arbre 38 qui par sa rotation provoque la séparation des contacts 18 et 21 et l'arrêt du courant.

Pendant cette manoeuvre, le profilé a achevé sa rotation de 90 degrés; le pôle s'immobilise dans la position représentée dans la figure 10, avec les contacts 7B et 8B mis à la terre par l'obturateur 62. Les distances d'isolement sont respectées. Le coffret de commande 5 bascule en même temps que les pôles qui sont venus se loger dans le tiroir 56. Cette disposition permet un sectionnement visible,évitant tout risque pour le personnel. La visualisation du sectionnement peut être accentuée au moyen d'une signalétique constituée par exemple par un tracé 5A de couleur visible. Un dispositif bien connu, mais non représenté, permet d'éviter l'extraction totale du tiroir, ce qui interdit l'accès au compartiment barres. Le tiroir peut être tiré suffisamment (figure 12) pour permettre un accès total aux pôles en vue de leur entretien ou de leur remplacement. On note que la disposition des pôles n'autorise la refermeture du tiroir qu'en position sectionnée. On observera enfin que lorsque le tiroir est ouvert, les pôles du disjoncteur auto-sectionneur peuvent être replacés en position verticale, par rotation du profilé métallique 4, par exemple pour réaliser des essais de déclenchement ou d'enclenchement des ampoules à vide.The operation of the self-disconnecting circuit breaker of the invention is as follows:

• in normal operation, the circuit breaker is in the configuration shown in Figure 9. The current flows between the cable 65 and the bar 59 preferably using the blades 7 and 8, so that a relatively small current flows through the vacuum bulb.
• if it is desired to interrupt the current, either for a normal operating maneuver, or in the event of a fault, an order is given to the operating member of the profile 4 which turns on itself in the direction of the arrow F1 in FIG. 9 ; this rotation causes the connection elements 20A and 20B to separate from the fingers 58D and 66D. The current passing through the blades 7 and 8 is switched in the vacuum bulb; an order is then given to the control mechanism of the shaft 38 which by its rotation causes the separation of the contacts 18 and 21 and the stopping of the current.

During this maneuver, the profile has completed its 90 degree rotation; the pole stops in the position shown in Figure 10, with the contacts 7B and 8B grounded by the shutter 62. The isolation distances are respected. The control box 5 switches over at the same time as the poles which have come to be housed in the drawer 56. This arrangement allows visible sectioning, avoiding any risk for the personnel. The visualization of the sectioning can be accentuated by means of signage constituted for example by a line 5A of visible color. A well known device, but not shown, avoids the total extraction of the drawer, which prohibits access to the bar compartment. The drawer can be pulled out enough (Figure 12) to allow full access to the poles for maintenance or replacement. It should be noted that the arrangement of the poles allows the drawer to be closed only in the sectioned position. Finally, it will be observed that when the drawer is open, the poles of the self-disconnecting circuit breaker can be replaced in a vertical position, by rotation of the metal profile 4, for example to carry out tripping or switching-on tests of the vacuum interrupters.

To constitute a complete cell (FIG. 13), the frame 55 is placed on a box 72 for the departure of the cables; moreover, a relaying box 73 can be placed above the box 55A, with display and display members 74 arranged on the front face.

It will be noted that the box 55A containing the drawer with the poles of the circuit breaker, the earthing switch, the isolators and the device for displaying the presence of voltage can be manufactured and checked in the factory and mounted on site.

Remember that the metal section 4, connected to the control box, is at ground potential; as the poles of the circuit breaker are mounted on a common profile, the risk of ignition between phases is practically non-existent, all priming occurring first on the ground.

The switching of the current and the sectioning by rotation of the metal section 4 integral with the control box is normally motorized, but it can also be carried out manually.

In FIG. 14, a distinction is made between the metal section 4, the control shaft 38 of the poles and one of the connecting rod 37; the corresponding pole has not been represented for the sake of clarity of the drawing.

The profile is held by two ball bearings 75 and 76 integral with the walls 56A and 56B of the drawer. The control box is secured to the profile 4, for example by welding. A pinion 77 is secured to the profile 4. A motor 78, fixed to the wall 56A of the drawer, drives, by a helical screw 79, with speed reduction, the pinion 77, which causes the profile 4 and the cabinet 5 to rotate, independently of the movement of the control shaft 38. The motorization of the sectioning which has just been described shows that the apparatus can be remote-controlled and that it can therefore equip the stations for which there is no maneuvering personnel or surveillance.

FIGS. 15 and 16 illustrate an embodiment, given by way of nonlimiting example, of an automatic operating mechanism for the flap 61B.

The box carries, as already mentioned, two slides 61A in which the flap 61B, which is a rectangular sheet, can slide.

The box carries, on its rear face, a movable disc 61C provided with a central hole 61D of suitable shape to receive the section 4 which projects beyond the drawer beyond the face 56B (see FIG. 14) and allow the disc to rotate when the pole support profile 4 turns on itself during a sectioning operation. When the profile is a square, as indicated above, the hole is advantageously square or rectangular. The flap is driven in translation by the rotation of the disc by means of two sets of linkages cooperating with a shaft 61E parallel to the plane of the flap and parallel to the profile 4. The shaft is fixed to the box 55A by means of bearings not shown. It is rotated by a connecting rod 61F articulated on the one hand on the disc 61C and on the other hand to a crank 61G wedged on the shaft 61E. The rotational movement of the shaft is converted into a translational movement communicated to the shutter by means of two sets of linkages. Only one of the sets of connecting rods, that of the bottom of the drawer, is described in detail, the other set, at the front of the drawer being completely identical. The first set of connecting rods comprises a connecting rod 61H wedged on the shaft 61E and articulated to a crank 61I articulated to the flap. During a sectioning maneuver, the support section 4, engaged in the hole of the disc 61C, is rotated in the direction of the arrow (Fig.15); the rotation of the disc 61C causes the rotation of the shaft 61E and the rod-crank assembly 61H-61I causes the translation of the flap 61B which obstructs access to the right part of the bar compartment. After the sectioning maneuver, if the drawer 56 is removed, a locking latch 61J engages in a notch 61K of the disc 61C, immobilizing the flap 61B in its position. This latch, fitted with a spring, is released when the drawer is replaced.

Box 5 contains an overcurrent relay used to control the opening of the device in the event of a fault resulting in overcurrent. The box also contains the mechanism for rotating the control shaft 38, making it possible to perform opening and closing cycles of the vacuum interrupter. FIG. 17 is a block diagram of this mechanism, the advantage of which is that it is directly linked to the control shaft 38 of the self-isolating circuit breaker. It suffices to give the principle of this mechanism; its implementation is within the reach of the skilled person who can usefully refer to the Techniques of Engineer, High voltage electrical switchgear, by Eugène MAURY, D 657-4, page 49.

In FIG. 17, we recognize the shaft 38 arranged inside the metal section 4 secured to the control unit 5.

The mechanism comprises a drum 80 provided with a spring and which constitutes the reservoir of operating energy. A gear motor 81 makes it possible to drive the drum to reset the spring. The drum drives in rotation a shaft 82 always rotating in the same direction under the action of the rebound of the spring; this shaft is associated with hooking devices 83 with electrical or manual control, making it possible to carry out the usual opening and closing cycles (for example an OPEN cycle, 0.1 seconds CLOSE, OPEN). An eccentric device 84 makes it possible to transform the one-way movement of the shaft 82 into an alternating circular movement communicated to the control shaft 38 of the poles of the self-disconnecting circuit breaker.

The mechanism comprises, as is well known, a manual resetting member comprising a crank 85 visible in FIGS. 1, 12 and 13.

The invention typically applies to the production of medium voltage cells (for example 36 kV) with high nominal current (typically 3150 amps and more).

FIG. 18 schematically represents a station produced by means of several circuit breakers such as 101 and 102; the self-disconnecting circuit breaker 101 is placed in a cell 110 similar to that shown with reference to FIGS. 9 to 13 and comprising the incoming cables 111; the other self-disconnecting circuit breakers are placed in coupling cells such as 120 coupled to cells such as 121 for busbar mounting.

Claims (24)

1. Multipole self-isolating disconnector comprising for each pole a double insulative cross-connection member (10) enclosing a vacuum bulb (14) and having at a first end a first connection member (20A) connected to a first terminal of the bulb and adapted to be electrically connected to an incoming feeder conductor and at a second end a second connection member (20B) connected to the other terminal of the bulb and adapted to be electrically connected to an outgoing feeder conductor, characterised in that each cross-connection member further comprises at least two metal blades (7, 8) passing completely through it and projecting from it to constitute current terminals (7A, 7B, 8A, 8B) adapted to be connected to said outgoing feeder conductor and to said incoming feeder conductor, respectively, the cross-connection members being fixed to a common metal bar (4) along which and protected by which runs an operating shaft (38) common to the bulbs and operated by a bulb operating mechanism contained in a box attached to the bar, the latter being rotatable, the terminals (7A, 8A, 7B, 8B) and the connection members (20A, 20B) previously referred to of the cross-connection member being adapted so that the rotation of the bar (4) first diverts the current flowing through said blades into the vacuum bulb (14) and then isolates the apparatus.
2. Self-isolating disconnector according claim 1 characterised in that the insulative cross-connection member of each pole comprises a first cavity in which the vacuum bulb (14) is housed, said bulb comprising an insulative jacket (15) closed by first and second metal flanges (16, 17), the first metal flange (16) being connected externally to one of said connection members (20A) and internally to a fixed contact (18) of the vacuum bulb, said second flange (17) having a mobile metal rod (22) passing through it and sealed to it, this rod carrying a second, mobile contact (21) of the vacuum bulb (14), the insulative cross-connection member comprising a second cavity communicating with the first cavity and in which is disposed a metal tube (25) mechanically connected to the vacuum bulb (14) and electrically connected to said mobile metal rod (22), said tube (25) containing an actuator rod (30) connected to said mobile metal rod (22), the insulative cross-connection members of each pole being fixed to said metal bar (4), the actuator rod (30) of the pole being mechanically connected to said actuator shaft (38) through a lever (32) articulated to an end piece (26) attached to the metal tube (25), an insulative arm (35) articulated at a first end to said lever (32) and at a second end to a link (37) keyed to said shaft (38), said end part (26) being mechanically and electrically connected to said metal tube (25) and carrying said second connection member (20B).
3. Self-isolating disconnector according to claim 2 characterised in that the first cavity includes interior grooves (12) parallel to the axis of the cross-connection member defining with the exterior wall of the vacuum bulb ventilation channels, the air circulating in the metal tube (25) and entering said channels via holes (25A) in said tube.
4. Self-isolating circuit breaker according to claim 2 characterised in that the vacuum bulb (14) is placed in an insulative cylindrical cage (13), for example a resin cage, disposed in said first cavity.
5. Self-isolating disconnector according to claim 4 characterised in that said cage (13) has interior grooves (13A) parallel to its axis, defining ventilation channels with the wall of the vacuum bulb (14), the air circulating in the metal tube (25) and entering said channels via holes (25A) in said tube.
6. Self-isolating circuit breaker according to any one of claims 2 to 5 characterised in that the insulation between said metal tube (25) and the wall of said second cavity is provided by a compressible insulative material sheath (27) threaded onto said metal tube (25) and engaged in said second cavity, fitted it being facilitated by the use of an insulative grease.
7. Self-isolating disconnector according to claim 6 characterised in that said sheath (27) is made of latex.
8. Self-isolating disconnector according to any one claims 2 to 7 characterised in that the kinematic system between said actuator rod (30) and said actuator shaft (38) includes a spring mechanism for taking up play.
9. Self-isolating disconnector according to any one of claims 2 to 7 characterised in that the end of the actuator rod (30) comprises a tubular end portion (30A) in which said mobile rod (22) is inserted, said mobile rod comprising a slot (22A) in which is inserted a first pin (22B) passing through said actuator rod, a spring (22C) bearing against a first bearing washer (22D) in contact with said end of the actuator rod (30) and against a second bearing washer (22E) engaged in the mobile rod (22) and held by a second pin (22F) passing through the mobile rod (22).
10. Self-isolating disconnector according to any one of claims 2 to 9 characterised in that said metal tube (25) is mechanically connected to the vacuum bulb and said metal tube (25) is electrically connected to said mobile contact rod (22) by a sleeve (15A) fixed to said second flange (17), a ring (15B) attached to said sleeve (15A) and to said tube (25), and an accordion or bush type contact (15C) disposed inside said ring and around said rod (22).
11. Self-isolating disconnector according to any one of claims 2 to 10 characterised in that said end part (26) comprises two half-collars (41, 42) clamped to said metal tube and abutted against the end of the insulative cross-connection member (10).
12. Self-isolating disconnector according to claim 11 characterised in that the half collars (41, 42) include lugs (45) cooperating with recesses in the insulative cross-connection member (10) to prevent rotation of said metal tube (25).
13. Disconnector according to any one of claims 6 to 12 characterised in that said sheath (27) is prevented from rotating by a circlip (28) clipped to said metal tube (25).
14. Self-isolating disconnector according to any one of claims 1 to 13 characterised in that the exterior surface of the insulative cross-connection member (10) is metallised in the area adjoining the support bar (4).
15. Self-isolating disconnector according to any one of claims 1 to 14 characterised in that the cross-connection member includes, near the fillet (10C) linking the two cavities, a metal grid (51A) incorporated into it when it is moulded and adapted to be held at the same potential as said metal tube (25).
16. Medium-voltage cubicle characterised in that it comprises at least one self-isolating disconnector as claimed in any one of claims 1 to 15.
17. Medium-voltage cubicle according to claim 16 characterised in that it includes a self-isolating disconnector as claimed in any one of claims 1 to 15 placed in a draw-out module (56) sliding in a box (55A) including support insulators (58) for a set of busbars (59) and support insulators (67) for an outgoing feeder cable (65), the metal bar supporting the self-isolating disconnector being articulated to two opposite faces (56A, 56B) of said draw-out module, the self-isolating disconnector in the isolated position fitting entirely within the draw-out module (56) which can be at least partially but largely withdrawn from the box (55A).
18. Medium-voltage cubicle according to claim 17 characterised in that the box (55A) includes a fixed first shutter (61) separating the space containing the busbars (59) from the space for the draw-out module (56).
19. Medium-voltage cubicle according to claim 17 or claim 18 characterised in that the box (55A) includes a mobile second shutter (61B) occupying a position above the first shutter (61) when the disconnector is in service and a position in which, with the first shutter (61), it entirely prevents access to the busbar space (59) from the draw-out module space (56) when the self-isolating disconnector is in the isolated position.
20. Medium-voltage cubicle according to claim 19 characterised in that the second shutter (61B) is moved by a disc (61C) rotated by rotation of the bar (4) and operating at least one set of links (61F, 61G, 61H, 61I) connected to said second draw-out module (61B) which slides in slides (61A) fixed to the box (55A).
21. Medium-voltage cubicle according to claim 20 characterised in that the disc (61C) incorporates a notch (61K) cooperating with a latch (61J) to immobilise the disc when the draw-out module (56) is withdrawn, the latch being unlocked by action of the draw-out module when the latter is closed.
22. Medium-voltage cubicle according to any one of claims 17 to 21 characterised in that the draw-out module (56) includes a partition (62) rotated by the rotation of the self-isolating disconnector on changing from the isolator engaged position to the disengaged position and earthing the poles when the self-isolating disconnector is in the isolated position.
23. Medium-voltage cubicle according to any one of claims 17 to 22 characterised in that the metal bar (4) is rotated by a gear motor (78) fixed to the draw-out module (56) and cooperating with a gear (77) attached to the bar (4).
24. Medium-voltage substation comprising a cubicle (110) as claimed in any one of claims 17 to 23 and at least one cubicle (120) including a self-isolating disconnector (102) as claimed in any one of claims 1 to 14 associated with a busbar riser compartment (121).

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