FR3038448A1 - HIGH VOLTAGE OR MEDIUM VOLTAGE CIRCUIT BREAKER WITH OPTIMIZED COMPRESSION CYLINDER - Google Patents

Abstract

The invention relates to a switching chamber (2) for a medium or high voltage electric circuit breaker (1), comprising a fixed body (32), a compression volume (6) designed to be filled with electric arc extinguishing fluid. for blowing an electric arc formed in the circuit-breaker (1) upon opening of the circuit-breaker (1), a movable compression member (44) closing the compression volume (6), and a sliding contact (12) configured to ensuring electrical contact of the compression member (44) to the fixed body (32) over the entire stroke of the compression member (44) within the fixed body (32). According to the invention, the sliding contact (12) is fixed to the movable compression member (44), sliding along the fixed body (32).

Description

MEDIUM OR HIGH VOLTAGE CIRCUIT BREAKER

OPTIMIZED COMPRESSION

DESCRIPTION

TECHNICAL FIELD The invention relates to a medium or high voltage circuit breaker comprising a compression volume for blowing an insulating gas over an electric arc established in this circuit breaker when it is opened in order to extinguish this arc. Such circuit breakers are for example suitable for use in voltages greater than or equal to 72.5kv or even 550 kv.

STATE OF THE PRIOR ART

The medium or high voltage circuit breaker of FIG. 1 comprises a thermal volume 5 which is fed by a compression volume 6 with fluid intended to be blown on an electric arc occurring during the opening of the circuit breaker 1. The compression volume 6 is closed upstream by a bottom 9 and downstream by a movable compression member 43 carrying the thermal volume 5. The movable compression member 43 of Figure 1 is of known structure. It has the shape of an elongate cylinder 43b monobloc closed by an end wall 43a carrying the thermal volume 5. The compression volume is thus delimited by the movable closed cylinder 43 and the fixed bottom 9 which is engaged in this cylinder mobile 43 forming a compression member.

This elongated cylinder 43b slides on a fixed sliding contact 16 and on a fixed sealing element 17. The sliding contact 16 surrounds the cylinder 43b being rigidly fixed to an inner face of the fixed body 32 of the circuit breaker. The sealing element is mounted at the periphery of the fixed bottom 9 which is engaged inside the movable cylinder 43b.

The circuit breaker 1 is shown in Figure 1 in an intermediate position between its fully closed position and its fully open position. In this intermediate position where the circuit breaker 1 passes the current, this electric current 19 then travels from the fixed body 32 to a fixed arcing contact 34 through successively the sliding contact 16, the mobile compression member 43 and a contact moving arc 46, to reach the fixed arc contact 34.

The object of the invention is to reduce the manufacturing cost of such a circuit breaker.

SUMMARY OF THE INVENTION In this regard, the subject of the invention is a circuit breaker for a medium or high voltage electrical line, comprising: an electrically conductive fixed body; a compression volume intended to be filled with extinguishing fluid; electric arc, the compression volume having an opening through which the compressed fluid is to flow towards an electric arc established in the circuit breaker when opening the circuit breaker, so as to blow the arc electrical, a mobile electrically conductive compression member closing the compression volume, and a sliding contact configured to provide electrical contact of the compression member to the fixed body over the entire stroke of the compression member within the body fixed.

According to the invention, the sliding contact is fixed to the mobile compression member.

Under these conditions, the sliding contact slides along the fixed body with the movable member which carries it, being in electrical contact with the fixed body throughout the movement. The compression member may thus have a reduced length, significantly less than its displacement stroke. It is thus no longer necessary for this compression member to have the shape of a cylinder or bowl of great length, as is the case in the state of the art.

The reduction of the dimensions of the compression member reduces its mass, and therefore its inertia. The power of the control system moving this compression member during the maneuvers of the circuit breaker can thus also be reduced.

Advantageously, the sliding contact comprises a ring of conductive fingers, or a conductive spring.

Advantageously, the inside of the fixed body is a cylinder, the compression member then having a general shape of sliding disk in the fixed cylinder along the axis of the fixed cylinder. The cylinder is of circular cross section.

According to an advantageous embodiment, the sliding contact is fixed at the periphery of the mobile compression member.

According to another particular embodiment, the circuit breaker comprises a sealing element at the periphery of the compression member, the sealing element being configured both to guide the compression member in displacement relative to the fixed body. and to seal the arc extinguishing fluid between the fixed body and the compression member.

Preferably, the sealing member is fixed to the compression member, being slidable relative to the fixed body.

In particular, the sealing element is preferably close to the sliding contact. In particular, the sealing element is housed in a sealing element support which is in direct mechanical contact with a sliding contact carrier in which the sliding contact is intended to be housed.

According to another advantageous embodiment, the circuit breaker comprises a moving element including a movable arcing contact and the compression member, the moving element being movable between an open position in which the circuit breaker is open and a position of closure in which the circuit breaker is closed, the compression member being rigidly secured in displacement of the movable arcing contact.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on reading the description of exemplary embodiments, given purely by way of indication and in no way limiting, with reference to the appended drawings in which: FIG. 1 is a schematic view of a medium or high circuit breaker voltage according to a known design of the prior art, in an intermediate position between its closed position and its open position, Figure 2 is a schematic view of the circuit breaker of Figure 1, in the open position, the FIG. 3 is a schematic view of a circuit breaker according to the invention, in an intermediate position between its complete closed position and its fully open position, FIG. 4 is a diagrammatic view of the circuit breaker of FIG. 'opening.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

Identical, similar or equivalent parts of the different figures bear the same numerical references so as to facilitate the passage from one figure to another.

Figures 3 and 4 show a circuit breaker 1 for medium or high voltage electrical line, according to the invention. The cutoff chamber 2 of the circuit breaker 1 is substantially annular about an axis 36, and comprises a mobile assembly 4 and a fixed support 3 of the moving equipment. The mobile assembly 4 is able to move relative to the fixed support 3 between an open position in which the circuit breaker 1 is open and a closed position in which the circuit breaker 1 is closed. The moving element 4 is shown in FIG. 3 in an intermediate position between its closed position and its open position, called the first intermediate position. In this position, an electric arc is likely to be formed between a movable arcing contact 46 and a fixed arcing contact 34. The arcing contacts 34 and 46 have, in known manner, complementary male and female shapes. The mobile assembly 4 defines a heat volume 5 filled with arc extinguishing fluid.

The fluid in the circuit breaker is likely to be of a different nature, provided that it has a sufficiently high dielectric constant and is gaseous by blowing the electric arc. The circuit breaker can be of different types, such as a generator or not, compressed gas, self-blowing or auto-pneumatic circuit breaker.

This arc extinguishing fluid is often a dielectric gas, for example SF6 which is known as sulfur hexafluoride. In this case, the circuit breaker 1 is gas isolated. The upstream and downstream directions are defined as the general direction of flow of the fluid along the axis 36, when this fluid is blown during the opening of the circuit breaker 1. The upstream of the thermal volume 5 is closed by a movable member The thermal volume 5 is surrounded by an enclosure 48 which extends downstream by a blast nozzle 42. The blast nozzle 42 directs the arc extinguishing fluid, so as to blow the formed electric arc. between the arcing contacts 34 and 46, when opening the circuit breaker 1. The compression member 44 is rigidly integral in displacement of the movable arcing contact 46 between the open position and the closed position. The compression member 44 thus moves in the same direction and the same direction as the moving arc contact 46.

The thermal volume 5 is supplied with arc extinguishing fluid by the compression volume 6. The compression member 44 comprises a movable wall which delimits the thermal volume of the compression volume 6. The mobile wall 44 is traversed by a or several openings 8 each closed by a valve 7 configured to let the compressed fluid flow from the compression volume 6 to the thermal volume 5, when the pressure of the fluid in the compression volume 6 exceeds a certain threshold. The compression volume 6 is closed upstream by a bottom 9 of the compression volume. The displacement of the movable wall 44 towards the bottom 9 compresses the fluid of the compression volume 6. The fluid expands in the compression volume 6 when the moving wall moves downstream. The bottom 9 of the compression volume is fixed and traversed by a central orifice through which the movable arcing contact 46 is guided in displacement relative to the fixed support 3. A fixed body 32 is situated at the periphery of the compression volume 6. The bottom 9 and the fixed body 32 are both part of the fixed support 3.

The interrupting chamber 2 also comprises a sealing element 14 situated between the fixed body 32 and the moving element 4. The sealing element 14 limits / prevents fluid leakage towards the outside of the compression volume 6. Furthermore, the sealing element 14 guides the moving assembly 4 in displacement with respect to the fixed support 3. The sealing element 14 takes for example a general shape of band or segment of band, annular around the axis 36.

The fixed body 32, the compression member 44, the movable arcing contact 46 and the fixed arcing contact 34 are electrically conductive. In general, the mobile unit 4 is electrically conductive, with the exception of the enclosure 48 and the nozzle 42 which are electrically insulating. The breaking chamber 2 comprises a sliding contact 12 electrically connecting the fixed body 32 and the compression member 44. The sliding contact 12 is annular. It may include recesses on its circumference. The sliding contact 12 is for example a ring of conductive fingers. Alternatively, the sliding contact 12 comprises an electrically conductive coil spring.

The circuit breaker according to the invention shown in FIGS. 3 and 4 differs from the circuit-breaker of the state of the art shown in FIGS. 1 and 2 in that the sliding contact 12 is fixed to the mobile compression member 44. The sliding contact 12 is then sliding with the compression member 44 along the axis 36, remaining in electrical contact with the fixed body 32 over the entire stroke of the mobile compression member 44. The sliding contact 12 is fixed to the periphery 13 of the mobile compression member 44, being housed in a support 13 sliding contact.

The change of structure of the electrical connection between the fixed body 32 and the mobile compression member 44 reduces the dimensions of the compression member along the axis 36 of the circuit breaker 1. More specifically, the body of the compression 44 of the circuit breaker according to the invention has a general shape of sliding disk in the fixed cylinder 32 of circular section. In other words, the mobile compression member 44 no longer includes an elongate cylinder. The compression volume 6 is delimited radially by the fixed body 32 instead of being by the compression member 44.

This results in mass savings, greater ease of manufacture of the circuit breaker 1, as well as a reduction in the manufacturing costs of the circuit breaker 1. In addition, the compression volume 6 has a larger volume because of the increase in of its radial dimensions. This increase in the compression volume 6 has the advantage of being substantially decorrelated from the other dimensions of the circuit breaker 1, in particular those of the thermal volume 5.

The circuit breaker according to the invention is distinguished from that of Figures 1 and 2 in that the sealing element 14 is fixed to the compression member 44. The sealing element 14 is sliding along the axis 36, being in direct mechanical contact with the fixed body 32 over the entire stroke of the mobile compression member 44. The mobile compression member 44 ceases to be a mechanical interface between the bottom 9 of the compression volume and the movable member 44. The bottom 9 of the compression volume is therefore directly in contact with the fixed body 32. The sealing element 14 is located near the sliding contact 12. With reference to FIGS. 3 and 4, the element Sealing 14 is housed in a support 15 of the sealing element which is in direct mechanical contact with the sliding contact support 13. The structure of the electrical connection between the fixed body 32 and the compression member 44 and, to a lesser extent, the position of the sealing element 14 reduce the number of mechanical interfaces in the circuit breaker 1, which leads to in particular to a better seal, in addition to facilitating the manufacture of the circuit breaker 1. It may also result in better conduction of the current in the circuit breaker 1.

Electric current 19 can flow in the first intermediate position of the circuit breaker 1, represented in FIG. 3. The electric current 19 flows along the fixed body 32, through the sliding contact 12, the mobile wall 44, the arcing contact mobile 46 and then to the fixed arc contact 34.

With reference to FIG. 4, the circuit breaker 1 is open. The mobile compression member 44 has moved upstream towards the bottom 9 of the compression volume 6. The valves 7 have opened under the effect of the pressure of the fluid in the compression volume 6. This fluid was then engulfed, according to the references 62 and 64, in the thermal volume 5 through the openings 8, before joining the blowing nozzle 42 according to the arrow 66 to blow an electric arc that can be formed between the arcing contacts 34 and 46 and / or to be evacuated inside the movable arcing contact 46 upstream in the direction of the arrow 67. The invention offers the possibility of reducing the length of the mobile compression member which makes it less expensive and easier to manufacture, while reducing the overall weight of the breaker with equivalent breaking performance. The invention can also be implemented quite simply on circuit breakers of known structure by machining the compression member.

The reduction in the number of mechanical and electrical interfaces between the mobile compression member and the fixed parts of the circuit breaker, such as the fixed body or the bottom of the compression volume, is likely to provide both advantages in terms of ease manufacturing circuit breaker, fluid tightness, and decreasing the total mass of the circuit breaker.

Furthermore, the size of the compression volume is likely to be increased to the equivalent external volume of the circuit breaker, since the fixed body radially delimits the compression volume. The dimensions of the thermal volume can remain unchanged.

Claims (7)

1. Circuit breaker (1) for medium or high voltage electrical line, comprising: an electrically conductive fixed body (32), a compression volume (6) to be filled with electric arc extinguishing medium, the compression volume (6) having an opening (8) through which the compressed fluid is intended to flow towards an electric arc established in the circuit breaker (1) when opening the circuit breaker (1), so blowing the electric arc, an electrically conductive movable compression member (44) closing the compression volume (6), and a sliding contact (12) configured to provide electrical contact of the compression member (44) to the body fixed (32) over the entire stroke of the compression member (44) inside the fixed body (32), characterized in that the sliding contact (12) is fixed to the movable compression member (44) . 2. Circuit breaker (1) according to the preceding claim, wherein the inside of the fixed body (32) is a cylinder, the compression member (44) having a general disc shape sliding in the fixed cylinder (32) along the axis (36) of the fixed cylinder (32). 3. Circuit breaker (1) according to any one of the preceding claims, wherein the sliding contact (12) comprises a ring of conductive fingers, or a conductive spring. 4. Circuit breaker (1) according to any one of the preceding claims, wherein the sliding contact (12) is fixed to the periphery (13) of the movable compression member (44). 5. Circuit breaker (1) according to any one of the preceding claims, comprising a sealing element (14) at the periphery of the compression member (44), the sealing element (14) being configured at the times to guide the compression member (44) in displacement relative to the fixed body (32) and to seal the arc extinguishing fluid between the fixed body (32) and the compression member (44). ). 6. Circuit breaker (1) according to the preceding claim, wherein the sealing member (14) is fixed to the compression member (44), being slidable relative to the fixed body (32). 7. Circuit breaker (1) according to any one of the preceding claims, comprising a moving element (4) including: a moving arcing contact (46), the compression member (44), the moving element (4) being movable between an open position in which the circuit breaker (1) is open and a closed position in which the circuit breaker (1) is closed, the compression member (44) being rigidly integral in displacement of the arcing contact mobile (46).