EP0749139A1 - Gasinsulated M.T. circuit breaker - Google Patents

Abstract

The circuit breaker (10) includes a protective insulating envelope (12) filled with a dielectric gas and housing a pair of cross rails (14,16) directly connected to an isolating switch (18) of the main circuit (19). The switch includes an envelope (17) housing a fix contact (20) attached to the first rail (14) with screws 21). A mobile contact (22) rotates about an axis (24) in a support (26) attached to the second rail (16). The breaker envelope includes an auxiliary circuit with a cut-off chamber (34) which houses a pair of arc contacts (36,38). One of the arc contacts is mobile and can slide longitudinally between open and close positions. The arc contacts are connected in parallel with the two rails via a conductor (40).

Description

• un circuit principal par pôle ayant un organe sectionneur composé d'un contact principal fixe, et d'un contact principal mobile , connectés électriquement à une paire de traversées d'amenée de courant,
• un circuit auxiliaire par pôle ayant une chambre de coupure renfermant un contact d'arc fixe et un contact d'arc mobile connectés respectivement au contact principal fixe , et au contact principal mobile par des moyens de liaison électrique,
• et un mécanisme de commande commun à tous les pôles et agencé pour fermer les contacts d'arc avant les contacts principaux, et pour ouvrir lesdits contacts d'arc après lesdits contacts principaux.

The invention relates to a multipolar medium-voltage circuit breaker housed in an insulating envelope filled with a gas with high dielectric strength, and comprising:

• a main circuit per pole having a disconnecting member composed of a fixed main contact and a movable main contact, electrically connected to a pair of current feed bushings,
• an auxiliary circuit per pole having a breaking chamber enclosing a fixed arcing contact and a movable arcing contact connected respectively to the fixed main contact and to the movable main contact by electrical connection means,
• and a control mechanism common to all the poles and arranged to close the arcing contacts before the main contacts, and to open said arcing contacts after said main contacts.

Such a circuit breaker is described in document FR-A 2 677 168, the breaking chamber being formed by a self-expanding cartridge communicating with the interior of the envelope, or a vacuum-sealed ampoule. A full range of circuit breakers uses a large number of devices depending on the operating voltage, rating, and breaking capacity. Each device corresponds to a main circuit of specific dimensions, and a suitable breaking chamber to be assembled mechanically and electrically. The manufacturing and production management of such a range of circuit breakers is complicated and expensive.

The object of the invention is to standardize and improve the manufacture of medium voltage circuit breakers.

The circuit breaker according to the invention is characterized in that each breaking chamber comprises an insulating support arm equipped with a hinge pin housed in a notch of a first support bracket for the movable main contact, and at least one stud fixing arranged opposite the axis and cooperating with a screw to secure said chamber to the envelope.

The vertical offset between the notch of the support bracket of the movable main contact, and the fixing stud on the envelope remains identical, regardless of the type of interrupting chamber, and of the disconnecting member. The choice of the breaking chamber and the organ disconnector can be performed at the last moment during assembly in the factory, which facilitates manufacturing management.

According to a characteristic of the invention, the tightening action of the screw at the level of the fixing stud makes it possible to ensure the mechanical assembly of the breaking chamber, together with its electrical connection to one of the supply terminals current.

According to a preferred embodiment of the invention, the movable main contact of the disconnecting member, associated with the main circuit comprises a pair of contact clamps carried by the ends of the parallel branches of the first U-shaped stirrup, each clamp cooperating with a contact pad forming part of a first cradle in the form of an inverted U constituting the fixed main contact.

According to another characteristic of the invention, the mobile main contact of the main circuit is modular, and comprises at least one additional pair of contact clips, arranged on a second bracket and / or a third support bracket framing said first bracket, and with increasing widths. The fixed main contact comprises a second cradle and / or a third cradle arranged opposite the contact clamps associated with the second and / or third stirrups.

• une paire de lames conductrices associée à un dispositif élastique à ressort de pression de contact,
• un premier trou pour l'introduction d'un maneton constituant l'axe de pivotement du contact principal mobile,
• un deuxième trou pour l'accouplement d'une biellette reliée au mécanisme de commande,
• et un troisième trou pour le passage du ressort, et d'une paire de cavaliers d'assemblage.

According to a development of the invention, each contact clamp comprises:

• a pair of conductive blades associated with an elastic device with contact pressure spring,
• a first hole for the introduction of a crank pin constituting the pivot axis of the movable main contact,
• a second hole for coupling a connecting rod connected to the control mechanism,
• and a third hole for the passage of the spring, and a pair of assembly jumpers.

• la figure 1 est une vue schématique en coupe du disjoncteur selon l'invention, les contacts étant représentés dans l'état ouvert ;
• la figure 2 est une vue de profil de la figure 1, après enlèvement du couvercle, le pôle de droite montrant le circuit principal après démontage de la chambre de coupure, le pôle intermédiaire montrant la chambre de coupure, et le pôle de gauche étant vide ;
• la figure 3 représente une vue en élévation de la chambre de coupure de la figure 1 ;
• la figure 4 est une vue en plan de la figure 3 ;
• les figures 5 et 7 sont des vues identiques de la figure 3 de deux variantes de réalisation ;
• les figures 6 et 8 montrent des vues en plan des figures 5 et 7 ;
• la figure 9 montre schématiquement le positionnement des différents types de chambres de coupure par rapport aux plots de fixation sur la paroi interne de l'enveloppe ;
• la figure 10 est une vue de détail à l'échelle agrandie, montrant le montage de la chambre;
• la figure 11 est une vue en élévation du circuit principal correspondant au calibre minimum, les contacts principaux étant représentés dans l'état fermé ;
• la figure 12 est une vue en perpective du circuit principal de la figure 11 ;
• les figures 13 et 15 sont des vues identiques de la figure 11, pour des calibres supérieurs ;
• les figures 14 et 16 représentent les vues en perspective du circuit principal selon les figures 13 et 15 ;
• la figure 17 montre une vue en perspective éclatée d'une pince de contact de l'organe sectionneur ;
• la figure 18 représente une vue en coupe de la partie médiane de la pince de contact.

Other advantages and characteristics will emerge more clearly from the description which follows of an embodiment of the invention given by way of nonlimiting example, and represented in the appended drawings, in which:

• Figure 1 is a schematic sectional view of the circuit breaker according to the invention, the contacts being shown in the open state;
• Figure 2 is a side view of Figure 1, after removing the cover, the right pole showing the main circuit after disassembly of the switching chamber, the intermediate pole showing the switching chamber, and the left pole being empty ;
• Figure 3 shows an elevational view of the breaking chamber of Figure 1;
• Figure 4 is a plan view of Figure 3;
• Figures 5 and 7 are identical views of Figure 3 of two alternative embodiments;
• Figures 6 and 8 show plan views of Figures 5 and 7;
• FIG. 9 schematically shows the positioning of the different types of interrupting chambers with respect to the fixing studs on the internal wall of the envelope;
• Figure 10 is a detail view on an enlarged scale, showing the assembly of the chamber;
• Figure 11 is an elevational view of the main circuit corresponding to the minimum rating, the main contacts being shown in the closed state;
• Figure 12 is a perspective view of the main circuit of Figure 11;
• Figures 13 and 15 are identical views of Figure 11, for larger sizes;
• Figures 14 and 16 show the perspective views of the main circuit according to Figures 13 and 15;
• FIG. 17 shows an exploded perspective view of a contact clip of the disconnecting member;
• Figure 18 shows a sectional view of the middle part of the contact clip.

In FIG. 1, a pole of a three-pole medium-voltage circuit breaker 10 is housed in a sealed insulating jacket 12 filled with a gas with high dielectric strength, in particular sulfur hexafluoride SF6. The pole includes a pair of bushings 14, 16 arranged in current supply ranges for supplying the circuit breaker.

The bushings 14, 16 are directly connected to a disconnecting member 18 of the main circuit 19, comprising inside the casing 17 a fixed main contact 20 secured to the internal end of the first bushing 14 by screws 21, and a movable main contact 22 pivotally mounted on an axis 24 of a first support bracket 26, which is secured to the second bushing 16 by fixing screws 28.

The casing 12 has a flange 29 closed by a cover 30 with the interposition of a seal 32. Inside the casing 12 is an auxiliary circuit with breaking chamber 34 containing a pair of contacts of arc 36, 38, one of which 38 movable is mounted to slide longitudinally between a closed position where it is in engagement with the fixed arcing contact 36, and an open position for separating the arcing contacts 36, 38.

The arcing contacts 36, 38 of the breaking chamber 34 are electrically connected by a connecting conductor 40 and a braid 42, respectively at the bushings 14 and 16, so as to constitute a parallel mounting. In the closed position, the arcing contacts 36, 38 ensure the shunting of the main contacts 20, 22.

In the example of FIG. 1, the breaking chamber 34 is formed by a cartridge 43 of an arc extinguishing device by autoexpansion and / or by rotation of the arc, said cartridge communicating with the internal volume of the casing 12 through the movable arcing contact 38 tubular.

It is also possible to replace the cartridge 43 of FIG. 1 by a vacuum interrupter, having a hermetically sealed enclosure with respect to the envelope 12 filled with SF6.

The actuation of the movable main contact 22, and of the movable arcing contact 38 is effected by means of a rotary shaft 44, sealingly traversing the wall of the casing 12 while being coupled outside to a control (not shown). Inside the casing 12, the shaft 44 carries a crank 46 at each pole.

The crank 46 is connected to the main movable contact 22 by a first link 48, and to the movable arcing contact 38 by a second link 50. The articulation of the links 48, 50 takes place at a point 51 of the crank 46, the assembly being arranged to close the arcing contacts 36, 38 before the main contacts 20, 22, and open the arcing contacts 36, 38 after the main contacts 20, 22.

Such a prior closing cycle, and subsequent opening cycle of the arcing contacts 36, 38 is well known to specialists, and it is unnecessary to describe in detail the operation.

In FIG. 2, the shaft 44 is common to all the poles, and extends transversely with respect to the intermediate walls 52, 54 delimiting the three compartments 56, 58, 60 adjacent to the poles. The right pole shows the integration of the disconnector member 18 of the main circuit in the compartment 60 after removal of the interrupting chamber 34 and the cover 30. The central compartment 58 illustrates the installation of the interrupting chamber 34 au- above the shaft 44. The compartment 56 on the left is shown empty after removal of the disconnector and of the corresponding breaking chamber. It is clear that the electrical equipment of each compartment 56, 58, 60 is identical, and corresponds to the pole represented in FIG. 1.

In FIGS. 3 and 4, the interrupting chamber 34 comprises a lower support arm 62 extending perpendicular to the longitudinal axis of the cartridge 43, and the end of which is equipped with an axis 64 of articulation. The cartridge 43 is further provided with a pair of fixing studs 66 located opposite the arm 62 in the longitudinal direction.

FIGS. 5 and 6 show a breaking chamber 34A adapted for a breaking capacity greater than that of the chamber 34 in FIGS. 3 and 4. The width between the two opposite lateral faces 68, 70 of the cartridge 43A is greater than that from the previous cartridge 43. the distance L1 measured in the longitudinal direction between the axis 64 and the studs 66 is preserved, as well as the transverse distance L2 between the articulation axis 64 and the longitudinal axis of the cartridge 43A.

In FIGS. 7 and 8, the breaking chamber 34B corresponds to a maximum breaking capacity, and the size of the cartridge 43B is greater than that of the cartridge 43A of FIGS. 5 and 6. The distances L1 and L2 are the same as those for cartridges 43 and 43A.

The plan view of FIG. 9 shows the quadrangular profiles of increasing sections of the different interrupting chambers 34, 34A, 34B. The spatial position of the fixing pads 66 remains unchanged, regardless of the type of breaking chamber. Each fixing stud 66 is pierced with an orifice 72 disposed opposite a threaded insert 74 housed in the body of the insulating casing 12. A connecting screw 76 passes through the orifice 72 of each stud 66, and is screwed into the insert 74.

In FIG. 10, the articulation axis 64 of the support arm 62 is engaged in a notch 78 in a U formed in a horizontal extension 80 of the bracket 26 for supporting the movable main contact 22. The intermediate part of the conductor of link 40 is interposed between each stud 66 and a shoulder of the casing 12, and the end pad of the conductor 40 is connected to the main circuit by the screws 21 for fixing the fixed main contacts 20 to the bushing 14.

In contrast, the connecting braid 42 is connected to an intermediate conductor 82 having an end pad pressed onto the base of the stirrup 26 by means of the screws 28.

The main circuit 19 shown in FIGS. 11 and 12, comprises a disconnecting member 18 with two identical contact clamps 84 constituting the movable main contact 22. The clamps 84 are carried by the ends of the two arms 86, 88 parallel to the stirrup support 26, and cooperate with contact pads 90, 92 constituting the main fixed contact 20. The contact pads 90, 92 are arranged at the ends of a first cradle 94 in U whose base is fixed to the bushing 14 by the screws 21. Each socket 84 is articulated on the corresponding branch 86, 88 by means of a crankpin 96. The structure of the clamps 84 will be described in detail below, with reference to FIGS. 17 and 18. The main circuit 19 according to Figures 11 and 12 is suitable for the minimum rating of the circuit breaker.

For higher nominal currents, it is necessary to make use of a main circuit 19A with four clamps 84 (FIGS. 13 and 14). The circuit of the two intermediate clamps 84 corresponds to that of FIGS. 11 and 12, but the two outer clamps 84 are carried by a second wider support bracket 26A, framing the first bracket 26. The two outer clamps 84 cooperate with ranges of contacts 90A, 92A integral with a second cradle 94A wider than the first internal cradle 94.

Figures 15 and 16 illustrate a main circuit 19B with six clamps 84, corresponding to the maximum rating of the circuit breaker. The circuit of the four intermediate clamps 84 is identical to that of FIGS. 13 and 14. The two outer clamps 84 are carried by a third support bracket 26B wider than the second 26A, and cooperate with contact pads 90B, 92B arranged at ends of a third cradle 94B framing the second cradle 94A.

The parallel branches 86, 86A, 86B; 88, 88A, 88B of the three stirrups 26, 26A, 26B have substantially similar lengths, so as to position the clamps 84 at the same level after superimposition of the common webs. It is the same for the branches of the three cradles 94, 94A, 94B.

To adapt the performance of the circuit breaker during assembly in the factory, in particular with regard to the rating and the breaking capacity, the type of breaking chamber 34, 34A or 34B is chosen, and the main circuit 19, 19A, 19B for obtain the specific combination adapted to the technical characteristics of each device.

As an example, for a rating up to 1200A (Figure 2), it is possible to choose three interrupting chambers 34 according to Figures 3 and 4, and three main circuits 19 according to Figures 11 and 12.

For a circuit breaker of intermediate rating up to 2500A, three interrupting chambers 34A are used according to FIGS. 5 and 6, and three main circuits 19A according to FIGS. 13 and 14.

The maximum rating of 3200A requires the combination of the breaking chambers 34B according to Figures 7 and 8, with the main circuits 19B of Figures 15 and 16.

The envelope 12 has a specific size depending on the combination chosen. It is thus possible to obtain a full range of circuit breakers with the maximum of standard parts.

The mounting of the circuit breaker 10 begins with the screwing of the stirrups 26, 26A, 26B and cradles 94, 94A, 94B on the bushings 14, 16, followed by the assembly of the breaking chambers 34. The articulation axis 64 of the arm support 62 is engaged in the corresponding notch 78 followed by the pivoting of the cartridge 43 so as to apply the fixing studs 66 against the internal wall of the envelope 12. The installation of the screws 76 ensures the mechanical fixing of the breaking chamber, and the electrical connection of the fixed contact 36 with the bushing 14. It then suffices to couple the movable contacts 22 and 38 to the transmission shaft 44 by means of the links 48, 50.

With reference to FIGS. 17 and 18, each contact clamp 84 of the disconnecting member 18 comprises a pair of blades 100, 102 held opposite one another by an elastic device 104 for the contact pressure. Each blade 100, 102 is equipped with a first hole 106 for the introduction of the crank pin 96 constituting the pivot axis 24 of the movable main contact 22, and with a second hole 108 for the coupling of the link 48. The elastic device 104 comprises a compression spring 110 passing through a third hole 112 in a direction perpendicular to the blades 100, 102. The positioning of the spring 110 is carried out by means of two jumpers 114, 116 of assembly arranged coaxially in the third hole 112 ensuring precompression of the spring 110. Each jumper 114, 116 is provided with two diametrically opposite retaining pins 118, 120, intended to engage in two notches 122, 124 of the blades 100, 102 while crossing the hole 112 during a first translational movement indicated by the arrow A in FIG. 17. A second movement of movement by quarter turn, indicated by the arrow B, then causes the retaining lugs 118, 120 to be hooked on ramps on the rear side of the blades (see Figure 18).

Claims (9)

Multipolar medium voltage circuit breaker housed in an insulating envelope (12) filled with a gas with high dielectric strength, and comprising: - a main circuit (19, 19A, 19B) per pole having a disconnecting member (18) composed of a fixed main contact (20), and a movable main contact (22), electrically connected to a pair of bushings ( 14, 16) of current supply, - an auxiliary circuit per pole having a breaking chamber (34, 34A, 34B) containing a fixed arcing contact (36) and a movable arcing contact (38) connected respectively to the main fixed contact (20), and to the movable main contact (22) by electrical connection means, - and a control mechanism common to all the poles and arranged to close the arcing contacts (36, 38) before the main contacts (20, 22), and to open said arcing contacts after said main contacts, characterized in that each interrupting chamber (34, 34A, 34B) comprises an insulating support arm (62) equipped with an axis (64) of articulation housed in a notch (78) of a first stirrup (26) for supporting the movable main contact (22), and at least one fixing stud (66) disposed opposite the axis (64) and cooperating with a screw (76) to secure said chamber to the envelope (12 ). Circuit breaker according to claim 1, characterized in that the fixed arcing contact (36) is electrically connected to the main fixed contact (20) by a connecting conductor (40), the intermediate part of which is interposed between the fixing stud ( 60) and a shoulder of the casing (12), and that the movable arcing contact (38) is electrically connected to the stirrup (26) by a flexible conductor, in particular by a braid (42). Circuit breaker according to claim 1, characterized in that the movable main contact (22) of the disconnector (18), associated with the main circuit (19) comprises a pair of contact clamps (84) carried by the ends of the branches ( 86, 88) parallel to the first U-shaped stirrup (26), each clamp (84) cooperating with a contact pad (90, 92) forming part of a first cradle (94) in the shape of an inverted U constituting the contact main fixed (20). Circuit breaker according to claim 3, characterized in that the movable main contact (22) of the main circuit (19A, 19B) is modular, and comprises at least one additional pair of contact clamps (84), arranged on a second bracket (26A ) and / or a third support bracket (26B) framing said first bracket (26), and having increasing widths. Circuit breaker according to claim 3 or 4, characterized in that the fixed main contact (20) comprises a second cradle (94A) and / or a third cradle (94B) arranged opposite the contact clamps (84) associated with the second and / or third stirrups (26A, 26B). Circuit breaker according to claim 5, characterized in that the parallel branches of all the stirrups (26, 26A, 26B) have substantially similar lengths so as to position the clamps (84) at the same level. Circuit breaker according to claim 1, characterized in that the notch (78) for housing the hinge pin (64) is arranged in a horizontal extension of the first bracket (26). Circuit breaker according to one of Claims 3 to 7, characterized in that each contact clamp (84) comprises: - a pair of conductive blades (100, 102) associated with an elastic device (104) with contact pressure spring (110), - a first hole (106) for the introduction of a crank pin (96) constituting the pivot axis (24) of the movable main contact (22), - a second hole (108) for coupling a connecting rod connected to the control mechanism, - And a third hole (112) for the passage of the spring (110), and a pair of jumpers (114, 116) for assembly. Circuit breaker according to claim 8, characterized in that each assembly jumper (114, 116) is provided with two diametrically opposed retaining pins (118, 120), and intended to engage in two notches (122, 124) of the blades (100, 102) during a first translational movement, the precompression of the spring (110) being ensured during a quarter-turn actuation causing the lugs (118, 120) to hang on ramps of the conjugate blade.

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