EP2575155B1 - Medium-voltage electric distribution apparatus - Google Patents

Description

The present invention relates to an electrical distribution apparatus intended to be interposed between two parts of an electrical circuit so as to ensure at least the function of current flow between the parts and cut-off of the current in the event of an electrical fault.

For example, an electrical distribution cell of the kind mentioned above, as described in the patent application, is known. FR 2 940 516 . This cell comprises a switch or a circuit breaker also performing the disconnector function and, in series with this switch (or circuit breaker) a selector at least two positions respectively a current passage position and a grounding position.
This cell is designed to conduct a current of 630 A and is therefore not able to conduct higher current levels, such as 1250A.
When it is necessary to increase the nominal current performance of such cells, see any similar cell, this requires significant investment and development, especially when these cells use expensive technologies such as the technique of shielded insulation.
In addition, these cells that can withstand a higher nominal current than the mid-range generally correspond within a range with low consumption volumes, which means that the industrial costs of such an adaptation are not justified.
In addition, the current conduction function is quite expensive and problematic in the case of vacuum circuit-breakers, this being due to the dimensioning of the contacts of the bulbs, and their high contact resistance, which varies with the number of cut-offs. performed.
On the other hand, developing such cells with high current increases the number of references of the subsets, without counting all the necessary peripheral developments ensuring the main functions of the cell, namely the dielectric and current distribution functions, this electrical function requiring in some cases a complex overmoulding of the bulb.

We know the document EP 0 172 409 describing apparatus having the features of the preamble of claim 1.

The present invention solves these problems and proposes a simple and economical electrical distribution cell that can withstand a large nominal current without considerably increasing the necessary investments and the number of subsets made.

For this purpose, the present invention relates to an apparatus according to claim 1.
According to a particular characteristic, the first electrical member is a circuit breaker or a switch with at least two positions, respectively a closed position and an open position, while the second electrical member is a disconnector with at least two positions respectively a closed position. and an open position.
According to another characteristic, said cut-off or interruption of the current element comprises a vacuum interrupter.

According to another characteristic, this apparatus comprises means for bringing together an assembly constituted by a so-called third crank hingably connected to a so-called second connecting rod, of a dead center line, so as to increase the gear ratio when the end of the closing stroke, so as to have at the end of the closure, a large angular travel of the switch control corresponding to a short compression stroke of the contact pressure springs.

According to another characteristic, this apparatus comprises means for bringing a dead center passage line closer to an assembly comprising a so-called third crank hingably connected to a so-called first connecting rod so that at the end of the opening maneuver of the apparatus, the control device opens the contacts of the first member by minimizing the amplitude of the rotation of the disconnector.

According to another characteristic, this apparatus is characterized in that it is controlled by a control device comprising a said second crank integral in rotation with the control shaft of the first electrical member, said crank being connected in an articulated manner to the one of the ends of a so-called second connecting rod, another end of which is connected in an articulated manner to one of the ends of a so-called third crank rotatably connected to a shaft rotatably mounted about a so-called third fixed axis of the frame , and another end of which is connected in an articulated manner to a so-called first link connected in an articulated manner, at another end, to a so-called first crank supporting the disconnector knife, said so-called first crank being mounted free to rotate about a so-called first fixed axis of the frame, the rotation of said shaft being prevented by an unlockable locking system to allow be its rotation during a maneuver of manual or automatic opening of the apparatus.

According to another characteristic, this apparatus is controlled by a control device comprising a so-called second crank integral in rotation with the control shaft of the first electrical member, said crank being connected in an articulated manner to one end of a connecting rod. said second whose other end is hingedly connected to one end of a crank said third rotatably connected to a shaft rotatably mounted about a said third fixed axis of the frame, and another end is connected in a hinged manner to a so-called first link connected in an articulated manner, at another end, to a so-called first crank supporting the disconnector knife, said so-called first crank being mounted free to rotate about a so-called first fixed axis of the chassis, the rotation of said shaft being prevented by an unlockable locking system to allow its rotation during a man manual or automatic opening of the apparatus, and in that it comprises means for providing, during the compression phase, contact pressure springs for closing the apparatus, a large rotation of the control shaft for performing sufficient rotation of the disconnector to achieve a distance necessary for holding the TTR.

According to another characteristic, the cut-off or interruption-of-current member comprises a support rod of its movable contact, which rod is secured to a sleeve comprising two bearing surfaces and around which the pressure spring of contact, said spring being interposed between on the one hand, a first said upper plate interposed between the first bearing surface of the sleeve and the spring, and secondly a so-called lower plate interposed between this spring and a bar, which bar is rotatably mounted relative to the said second rod and slidably mounted around the sleeve, said bar being supported by means of two opposite flats respectively on the so-called bottom plate and the second bearing surface of the sleeve.

According to another characteristic, this apparatus is a medium voltage electrical distribution apparatus.

• La figure 1 illustre schématiquement un appareillage électrique selon une réalisation particulière de l'invention, ledit appareil étant en position fermée.
• La figure 2 est une vue identique à la précédente, l'appareillage étant en position ouverte,
• La figure 3 est une vue de côté dudit appareillage, selon une réalisation particulière de l'invention, dans une position fermée de l'appareillage,
• La figure 4 est une vue identique à la précédente, une partie du mécanisme ayant été retirée de façon à mieux faire apparaître la liaison mécanique au niveau des ressorts de pression de contact,
• La figure 5 est une vue de côté identique à la figure 3, dans une position ouverte du sectionneur et fermée de l'ampoule,
• La figure 6 est une vue identique à la figure 4, dans la position de l'appareillage illustrée sur la figure 5,
• La figure 7 est une vue identique à la figure 5, dans une position ouverte du sectionneur et de l'ampoule,
• La figure 8 est une vue partielle en perspective, illustrant une partie dudit appareillage sans l'ampoule et le sectionneur, et
• Les figures 9 et 10 sont deux vues partielles en coupe, illustrant la liaison mécanique entre la tige de support du contact mobile de l'ampoule et les manivelles de l'arbre des pôles.

But other advantages and features of the invention will become more apparent in the detailed description which follows and refers to the accompanying drawings given solely by way of example and in which:

• The figure 1 schematically illustrates an electrical apparatus according to a particular embodiment of the invention, said apparatus being in the closed position.
• The figure 2 is a view identical to the previous one, the apparatus being in the open position,
• The figure 3 is a side view of said apparatus, according to a particular embodiment of the invention, in a closed position of the apparatus,
• The figure 4 is a view identical to the previous one, a part of the mechanism having been removed so as to better show the mechanical connection at the contact pressure springs,
• The figure 5 is a side view identical to the figure 3 in an open position of the disconnector and closed of the bulb,
• The figure 6 is a view identical to the figure 4 , in the position of the apparatus illustrated on the figure 5 ,
• The figure 7 is a view identical to the figure 5 in an open position of the disconnector and the bulb,
• The figure 8 is a partial perspective view, illustrating a part of said apparatus without the bulb and the disconnector, and
• The figures 9 and 10 are two partial views in section, illustrating the mechanical connection between the support rod of the movable contact of the bulb and the cranks of the pole shaft.

On the Figures 1 and 2 , we see a multipole electrical equipment comprising for each pole two cells 1.2 mounted in parallel and electrically connected on one side, to a first set of bars a and the opposite side, to a second set of bars b.
The first cell 1, located on the right of the figure, comprises in this particular embodiment, a vacuum circuit breaker 3 comprising a vacuum interrupter 4 in series. with a two-position switch 5 respectively a closed position and a grounding position.
The second cell 2 located to the left of the first, comprises a switch with two positions respectively a closed position of passage of the current and a sectioning position.
These two cells are mechanically connected so as to obey a particular sequence which will be described in what follows.
On the figure 1 , the equipment is in the closed position, the two circuits being closed because the circuit breaker and the disconnector are closed, the rated current being distributed in the two cells.
To switch to the open position, it is necessary to first open the disconnector 5 of the second cell, so that the current is completely derived in the circuit breaker 3 of the first cell.
During this opening, it is imperative to reach a sufficient isolation distance of the contacts 6,7 of the disconnector 5 so that when the breaking contacts 8,9 begin to separate thereby cutting the current, there is no dielectric re-breakdown at the disconnector when the transient voltage recovery occurs.
Conversely, when switching to the closed position of the apparatus, it is necessary to first close the bulb 4 in order to establish the current through this member, and then to close the disconnector 5 so that the current is distributed in the two electric cells 1,2.
The apparatus according to the invention is controlled by a control device allowing to drive by a single action of the operator, the contacts 8,9 of the bulb 4 and 6,7 of the disconnector 5 so as to guarantee the steps previously mentioned.
On the Figures 3 to 7 , have been shown on the left side of the figures, the disconnector 5 comprising a knife 10 constituting a movable contact and a fixed stud 11 representing a fixed contact.
This knife 10 is supported by a crank 12 said first free fit in rotation about an axis (X) said first fixed belonging to the frame of the apparatus.

On the right side of the figures, the bulb 4 of the circuit breaker has been represented, said bulb comprising, in a manner known per se, an envelope of substantially cylindrical shape enclosing a fixed contact 8 with respect to said envelope and a movable contact 9 supported by a rod. mobile 13 along the axis of the bulb, said rod 13 having at one of its ends, a contact pad 14 and being mechanically connected by its opposite end to a crank 15 said second integral with a shaft A said pole shaft or control shaft of the bulbs, said shaft supporting a number of cranks, this number corresponding to the number of poles of the apparatus.
This shaft has poles is rotatably mounted about a Y axis fixed relative to the frame of the apparatus.
Each of these so-called seconds handwheels 15 has an end 15a integral in rotation with the pole shaft, and an opposite end 15b, mechanically connected to the control rod of the movable contact of the apparatus. For this purpose, a bar 16 forming a partial ball joint is mounted articulated in an opening provided at this end of the crank 15, this bar having two opposite flats 16a, 16b and being traversed by a sleeve 17 slidably mounted within this rod and having a threaded tubular orifice 18 inside which is mounted and screwed the control rod 13 of the movable contact 9 of the bulb 4. It is also seen that this sleeve 17 has at its two opposite ends, two diameter parts. 19,20 and respectively forming two bearing surfaces 21,22.
Around this sleeve 17 are also mounted a so-called first plate 23 having a face 23a bearing on one of said 21 said abovementioned abutment surfaces 21,22 of the sleeve 17, and whose other face 23b serves as surface d pressing one end 24a of a contact pressure spring 24, which is supported by its opposite end 24b, on a so-called second plate 25 mounted around the sleeve 17 and bearing on one 16a of the flats of the aforementioned ball, while the other flat portion 16b of the ball joint is intended to bear against the so-called second bearing surface 22 of the sleeve.
The so-called first crank 12 and the so-called second crank 15 are mechanically connected by a mechanical assembly comprising a so-called first link 25 connected in an articulated manner by one of its ends, to the so-called first crank 12 and at its opposite end, at one end of a so-called third crank 26 integral with a shaft rotatably mounted about an axis said third Z fixed with respect to the frame of the apparatus. This so-called third crank 26 is also connected in an articulated manner by another end, at one of the ends of a so-called second rod 27, which is connected in an articulated manner by another of its ends to the so-called second crank 15 secured to the pole tree A.
The operation of the control device of the electrical equipment described above, and corresponding to a particular embodiment of the invention will be described in the following with reference to the figures.
On the figures 3 and 4 , the control device is in the closed position, the knife 10 of the disconnector 5 being closed on the fixed pad 11 and the fixed 8 and movable contacts 9 of the bulb 4 are closed. In this position, the control shaft A of the circuit breaker 3 is locked by an attachment system preventing it from being rotated under the effect of the opening springs not shown and mounted around the contact pressure springs. 24, these springs also bearing on the above-mentioned lower plate 25. In this position, the contact pressure springs 24, as well as the opening springs of the circuit breaker mechanism 3, are compressed and the so-called second cranks 15 are in high position.
During an opening maneuver, the locking device of the control shaft A of the circuit breaker 3 is deactivated, which leads to the fact that the contact pressure springs 24 can initially decompress and lead at the same time time the cranks said seconds 15 on which they are supported, in rotation in the clockwise direction, through the said lower plate 25 bearing on the ball 16, which is integral with the crank said second 15. This involves , by means of the so-called second rod 27, the rotation of the so-called third crank 26 integral with the control shaft in the clockwise direction, and thereby the rotation of the so-called first rod 25 and also of the said first crank 12 supporting the knife 10, which rotates in the clockwise direction thereby causing partial opening of the movable contact 10 of the 5. In this partially open position of the disconnector 5 illustrated on the figures 5 and 6 , the separation distance of the switch contacts, is sufficient to hold the TTR (transient recovery voltage) which is the voltage that will be established across the contacts of the disconnector and the bulb when a new closing of the 'equipment. During this movement in rotation of the cranks said seconds 15, these cranks did not drive the drive rod 13 of the movable contact 8 of the bulb, because during this movement, the spring 24 has driven the plate 25 in translation the along the sleeve 17, which plate 25 has transmitted this movement to the bar 16, but this set has moved without reaching the shoulder, located at the bottom of the sleeve and formed by the so-called second bearing surface 22 of the sleeve 16 .
At this stage of operation of the mechanism, the opening springs of the mechanism, which are also resting on the so-called bottom plate 25, will take over and drive the shaft of the poles A, and the cranks 15 in the direction of the clockwise, which causes the displacement of the rod 13 and thus the opening of the contacts 8, 9 of the bulb 4, as illustrated in FIG. figure 7 . This movement of the cranks will be transmitted to the knife of the disconnector via the kinematics described above.
During a reverse closing operation of the apparatus, the closing springs of the mechanism drive the pole shaft A and the so-called second cranks 15 counterclockwise, which causes compression of the springs. contact pressure 24 via the second bearing surface 22 of the sleeve 17, the bar 16 and the lower plate 25. The closing force is then transmitted by these springs 24 to the rod 13 of driving the movable contact 9 of the bulb 4 through the so-called upper plate 23 and the other bearing surface 21 of the sleeve 17. This rotational movement of these cranks 15 causes the other, the counterclockwise rotation of the so-called third crank 26 via the so-called second rod 27, and the rotation in the counterclockwise direction of the so-called first crank 12 by means of the so-called first connecting rod, which results in the closing the contacts 8, 9 of the disconnector 5, illustrated position on the figures 3 and 4 .
Thus, the lengths of the connecting rods and cranks are chosen such that during this compression phase of the contact pressure springs 24, the rotation of the control shaft A makes it possible to achieve sufficient rotation of the movable contact of the disconnector 5. to reach the distance that it was necessary to reach during the opening to maintain the transient recovery voltage.
It appears, on the figure 3 in particular, that the driving kinematics of the cut-off contacts 8, 9 has been made so as to increase the gear ratio at the end of the closing stroke. This has been achieved by creating a rapprochement to a dead center line L between the so-called second rod 27 and the third crank 26, at the end of closing.
The drive kinematics of the disconnector 5 were made by amplifying this large angular travel of the pole shaft to allow rotation of the disconnector allowing the holding of the TTR.
At the end of the opening maneuver of the disconnector 5, this kinematics is performed in such a way that one also approaches a dead center passage line M between the so-called third crank 26 and the so-called first rod 25 at the end. opening operation, so as to allow the control to open the cutoff contacts by minimizing the rotation of the disconnector. In addition, this neutral passage line allows the switch 5 to be gently stopped and thus to avoid oscillating violently at the end of opening, which could cause parasitic rotation movements of the control at the end of opening.
Thus, the control device of the apparatus according to the invention has been designed so as to produce two different kinematics for each electrical member, each member being mechanically connected to the output shaft of the circuit breaker control device. gear ratios being different between the two kinematics, these ratios being determined by the ratios of length between the different connecting rods and cranks.
The present invention has thus made it possible to produce a mechanical device making it possible to maneuver in the same maneuver a cut-off member and a disconnecting member arranged in parallel and whose disconnecting member must open first in order to derive all the current in the cut-off member, and whose sectioning member must close last, as this avoids to have a power of closure, in order to derive a part of the current of the cut-off device, this after closure of the circuit by the sectioning member.
This device ensures a sufficient isolation distance of the disconnector for the holding of the TTR before the cut-off contacts start to separate, this using the compression / decompression phases of the contact pressure springs to actuate the disconnector .
This device makes it possible to maneuver two electric organs with a shift of the opening and the closing of one with respect to the other, with a kinematics without rupture of movement constituted by pivot connections (no light for empty strokes ) and therefore not generating shocks.
This device makes it possible to maneuver two electric members whose offset from one with respect to the other is guaranteed by a rigid and reliable kinematic chain.

This device also makes it possible to guarantee the state concordance of two different electrical organs (one can not be opened if the other is not).
This ensures a reliable image of the position of the two electrical components relative to that of the control.

Naturally, various modifications are possible. The number of modules is not limited to three. The invention also applies to dipole, quadrupole or even hexa polar or octagonal polar bulbs, the drive mechanism can be of any type, ie with separate closing and opening springs, with a single spring, single spring for closing and opening.

Claims (9)

1. Electrical distribution apparatus intended to be interposed between two parts of an electrical circuit so as to provide at least the function of channelling current between the parts and of disconnecting the current in the event of an electrical fault, said apparatus including what is called a first electrical disconnection or interruption unit (3), and what is called a second electrical disconnector unit (5), these being connected in parallel, the two electrical units both being able to adopt an open position and a closed position, respectively in the open position and in the closed position of the apparatus, the abovementioned current interruption or disconnection unit (3) having contact pressure springs (24) able to provide the contact pressure between the fixed and mobile contacts (8, 9) of said interruption and disconnection unit (3) after these contacts are closed, the compression/decompression phase of these contact pressure springs (24) being used to actuate the disconnector (5),
   characterized in that the opening and the closure of the first and second electrical units is controlled by the first electrical unit (3), and in that, when the apparatus switches from the closed position to the open position, the contacts (6, 7) of the disconnector unit (5) are first of all opened, creating an arc and an arc voltage between its contacts, allowing the current to be tapped off substantially completely into the disconnection or interruption unit (3), the opening of these contacts continuing until a sufficient isolation distance between the contacts of said disconnector unit is achieved, before the contacts (8, 9) of the disconnection or interruption unit (3) are opened, so as to avoid any repeated dielectric breakdown in the disconnector unit when the transient recovery voltage (TRV) is established after the contacts of the two units are closed,

   - in that it includes means for first of all closing what is called the first electrical unit (3) when switching from the open position to the closed position, so as to establish the flow of current through this unit, and then closing the second electrical unit (5) so that the nominal current is distributed in the two abovementioned electrical units (3, 5),

   - in that it includes a control device including what is called a second crank (15) that rotates jointly with the control shaft A of the first electrical unit (3), called pole shaft, said crank (15) being linked in an articulated manner to one of the ends of what is called a second rod (27), another end of which is linked in an articulated manner to one of the ends of what is called a third crank (26) that rotates jointly with a shaft mounted so as to rotate about what is called a third fixed axis Z of the chassis, and another end of which is linked in an articulated manner to what is called a first rod (25) linked in an articulated manner, by another end, to what is called a first crank (12) supporting the cutter (10) of the disconnector (5), said what is called first crank (12) being mounted so as to rotate freely about what is called a first fixed axis X of the chassis,

   - in that this control device is controlled by the decompression of the contact pressure springs (24), and in that, prior to the opening of the contacts (8, 9) of the current disconnection or interruption unit (3), this control device controls part of the opening of the contacts of the second unit (5), such that, when this decompression phase has ended, and the contacts (8, 9) of said disconnection or interruption unit (3) begin to open, the separation distance of the contacts (6, 7) of the second unit (5) is enough to withstand the transient recovery voltage (TRV), and in that said apparatus includes means so that, at the end of an opening manoeuvre of the apparatus, the control device opens the contacts of the first unit while minimizing the amplitude of the rotation of the disconnector, whereas the gear ratio between the pole shaft A and the drive crank for the disconnection contacts (8, 9) is increased at the end of closure travel of the connection contacts, these ratios been determined by the length ratios between the various rods and cranks.
2. Apparatus according to Claim 1, characterized in that what is called the first electrical unit is a circuit breaker or a switch having at least two positions (3), respectively a closed position and an open position, whereas the second electrical unit is a disconnector (5) having at least two positions, respectively a closed position and an open position.
3. Apparatus according to Claim 1 or 2, characterized in that said current disconnection or interruption unit (3) includes a vacuum tube (4).
4. Apparatus according to any one of the preceding claims, characterized in that it includes means for bringing an assembly formed by a what is called a third crank (26) linked in an articulated manner to what is called a second rod (27) close to a dead point crossing line L, so as to increase the gear ratio at the end of closure travel, so as to have, at the end of the closure, a large angular travel for controlling the disconnector (5) corresponding to a small compression travel of the contact pressure springs (24).
5. Apparatus according to any one of the preceding claims, characterized in that it includes means for bringing an assembly including what is called a third crank (26) linked in an articulated manner to what is called a first rod (25) close to a dead point crossing line M, such that, at the end of an opening manoeuvre of the apparatus, the control device opens the contacts (6, 7) of the first unit (3) while minimizing the amplitude of the rotation of the disconnector (5).
6. Apparatus according to any one of the preceding claims, characterized in that it includes a fastening system able to prevent the rotation of said shaft, this fastening system being able to be unlocked so as to allow it to rotate during a manual or automatic opening manoeuvre of the apparatus.
7. Apparatus according to any one of the preceding claims, characterized in that it is controlled by a control device comprising what is called a second crank (15) that rotates jointly with the control shaft A of the first electrical unit (3), said crank (15) being linked in an articulated manner to one of the ends of what is called a second rod (27), another end of which is linked in an articulated manner to one of the ends of what is called a third crank (26) that rotates jointly with a shaft mounted so as to rotate about what is called a third fixed axis Z of the chassis, and another end of which is linked in an articulated manner to what is called a first rod (25) linked in an articulated manner, by another end, to what is called a first crank (12) supporting the cutter (10) of the disconnector (5), said what is called first crank (12) being mounted so as to rotate freely about what is called a first fixed axis X of the chassis, the rotation of said shaft being prevented by a fastening system that is able to be unlocked so as to allow it to rotate during a manual or automatic opening manoeuvre of the apparatus, and in that it includes means for providing, during the phase of compressing the contact pressure springs (24) to close the apparatus, a large rotation of the control shaft A, making it possible to perform a sufficient rotation of the disconnector (5) to achieve a distance necessary to withstand the TRV.
8. Apparatus according to any one of the preceding claims, characterized in that the current disconnection or interruption unit (3) includes a rod (13) for supporting its mobile contact (9), which rod (13) is joined to a sheath (17) including two bearing surfaces (21, 22) and around which the contact pressure spring (24) is mounted, said spring (24) being interposed firstly between what is called an upper first plate (23) interposed between the first bearing surface (21) of the sheath (17) and the spring (24), and secondly what is called a lower plate (25) interposed between this spring (24) and a bar (16), which bar (16) is mounted so as to rotate with respect to what is called the second rod (27) and mounted so as to slide around the sheath (17), said bar (16) bearing, by way of two opposing flat spots (16a, 16b), respectively on what is called the lower plate (25) and the second bearing surface (22) of the sheath (17).
9. Apparatus according to any one of the preceding claims, characterized in that it is a medium-voltage electrical distribution apparatus.

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