INTERNAL TULIP SLEEVE OF THE FEMALE ARCING CONTACT OF A HIGH VOLTAGE ELECTRIC CIRCUIT BREAKER

Abstract

An internal tulip sleeve for the female arcing contact of a high voltage circuit breaker. According to the invention, this sleeve comprises a body of non-magnetic steel or of copper-tungsten alloy, this body comprising an internal face covered with copper.

Claims

1. An internal tulip sleeve for a female arcing contact of an alternating high voltage circuit breaker, this sleeve comprising a body of non-magnetic steel or of tungsten copper alloy, this body comprising an inner face covered with copper.

2. The sleeve according to claim 1, wherein the body comprises an outer face which is also covered with copper.

3. The sleeve according to claim 1, wherein the inner face of the body is covered by a layer of copper obtained by chemical deposit of vaporized copper or by electro deposition, or fabricated separately and assembled.

4. The sleeve according to claim 2, wherein the outer face of the body is covered by a layer of copper obtained by chemical deposit of vaporized copper or by electro-deposition, or fabricated separately and assembled.

5. The sleeve according to claim 1, wherein the body and the copper covering the inner face of the body are two distinct parts, the copper covering the inner face being mounted inside the body.

6. The sleeve according to claim 2, wherein the body and the copper covering outer face of this body are formed by two distinct parts, the copper covering the outer face being mounted around the main body.

7. A high voltage circuit breaker comprising the female arcing contact comprising the internal sleeve as defined in claim 1.

8. The high voltage circuit breaker according to claim 7, isolated with dielectric gas and arranged to blow gas to an electrical arc ignited upon opening, this circuit breaker comprising a collector to condense copper vaporized from the inner face of the internal sleeve upon opening of the circuit breaker, this collector being located downstream of the internal sleeve with respect to a flow of dielectric gas blown upon opening of the breaker, in order to condense the copper vaporized by this electrical arc.

9. The high voltage circuit breaker according to claim 8, wherein the collector comprises a support of thermally insulating material which carries on one of its faces a metallic wall to condense vaporized copper.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a longitudinal section of an internal sleeve of a female arcing contact of a high voltage circuit breaker according to the invention;

[0027] FIG. 2 is a longitudinal section of a female arcing contact of a circuit breaker having an internal sleeve according to the invention;

[0028] FIG. 3 is a longitudinal section of a part of a high voltage circuit breaker comprising a support carrying a female arcing contact which comprises an internal sleeve according to the invention when an electric arc is ignited;

[0029] FIG. 4 is a longitudinal section of a part of a high voltage circuit breaker comprising a support of the female arcing contact in the region comprising an exhaust tube connected to the female arcing contact;

[0030] FIG. 5 is a longitudinal section of a connection spacer which comprises a collector which is included in the circuit breaker according to the invention in order to collect copper vaporized by the arc.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

[0031] The internal sleeve of a female arcing contact of a circuit breaker according to the invention, marked 1 in FIG. 1, has a general rotationally symmetrical shape with respect to a longitudinal axis AX. It comprises a first extremity 2 for electric contact with a male contact, and a second extremity for mechanic and electric connection, marked 3.

[0032] This internal sleeve 1 comprises a central portion 4 which is tubular and which has one extremity at right angle that corresponds to the contact extremity 2 of the sleeve. It has an opposed extremity extended by a flare 6 which corresponds to the connection extremity 3. The main body of the central portion 4 and of the flare extremity 5 is a single part 6 which is the main body of the internal sleeve 1.

[0033] Flare 5 is externally delimited by a cylindrical surface 7 having a diameter which is greater than the external diameter of the central tubular portion 4. It comprises a circular rib 8 at its external surface.

[0034] The inner surface of this sleeve, marked 9, comprises a cylindrical part 10 corresponding to the inner face of the central tubular portion 4 and which is extended by a conic part 12 corresponding to the inner face of the flare region 5.

[0035] This conic part 12 of the inner surface expands from the cylindrical part 10 from which it extends, to connect to an extremity edge of the cylindrical surface 7 which corresponds to the connection extremity 3.

[0036] This internal sleeve 1 is intended to be mounted in the female contact of a circuit breaker as seen on FIG. 2, this internal sleeve 1 being mounted at the extremity of an exhaust tube 13 to extend it. According to this arrangement, a part of the flare 5 is inserted in the extremity of the exhaust tube 13. The inner diameter of the exhaust tube 13 corresponds to the outer diameter of cylindrical surface 7, and the circular rib 8 is applied against the terminal edge of the exhaust tube 13.

[0037] The exhaust tube 13 and the internal sleeve 1 which extends this tube are both oriented coaxially, along axis AX which corresponds to the longitudinal axis of the circuit breaker wherein these elements are mounted.

[0038] This internal sleeve 1 is surrounded by a first tubular element 14 which is surrounded by a second tubular element 16. These elements are secured to each other by an external sleeve 17 which overlaps the extremity of the exhaust tube 13 and a portion of internal sleeve 1 with its surrounding elements 14 and 16. This external sleeve 17 grips these components.

[0039] The female arcing contact 18 is intended to receive a male contact with an extremity having the shape of a finger, and which is inserted in the internal sleeve 1 to allow that the electric current can flow.

[0040] The male contact, marked 19 on FIG. 3 and the female contact 18 are movable in translation relative to each other along the longitudinal axis AX, to be spaced one from the other upon opening of the circuit breaker, as seen in FIG. 3.

[0041] As it is the case in FIG. 3, the female contact 18 with the exhaust tube 13 that it extends, are surrounded and carried by a support 21. All these components are mounted into an insulating envelope, which is not visible in the figures, and which is filled with dielectric gas such as SF6, the circuit breaker being here arrange to blow this gas to the electrical arc ignited between its arcing contacts, in order to extinguish this electrical arc.

[0042] The extremity of support 21 comprises a main opening which surrounds the female contact 18, and which carries an insulating sleeve 22 which extends this support 21 to surround the male contact 19 even when it is spaced apart from the female contact.

[0043] When the circuit breaker is being opened, i.e. when the male contact is spaced from the female contact, an electric arc is ignited between the male contact and the interior face of the internal sleeve 1. This electrical arc, marked A in FIG. 3 comprises one root on the male contact 19 and another root on the inner surface 10 of the internal sleeve 1.

[0044] According to the invention the internal sleeve 1 comprises a body 6 which is made of a non-magnetic steel or a tungsten copper alloy, but its inner face, and possibly the outer face of this body, is covered with copper.

[0045] The layer of copper 10 can be formed at the surface of the body by chemical deposit of vaporized copper, or by electro-deposition. This layer can also be made of an additional part of copper mounted inside the body 6 of the internal sleeve.

[0046] Another layer of copper 11 can as well be present at the outer face of this body, resulting from chemical deposit of vaporized copper, electro-deposition, or made of an additional part mounted outside the body 6.

[0047] Upon opening of the circuit breaker, as in FIG. 3, the electrical arc A provokes an erosion of the inner face 9 which is made of copper. This erosion allows transferring instantly a part of the heat generated by the arc, in order to diminish the temperature around this arc.

[0048] The internal sleeve according to the invention can then be partially eroded by the electrical arc to transfer a part of its heat, but it cannot be destroyed by this arc by virtue of its main body made of non-magnetic steel or tungsten copper alloy.

[0049] In other words, the invention combines the advantages of an internal sleeve of copper which can be eroded by the arc to instantly transfer heat, with the advantages of a sleeve of non-magnetic steel or tungsten copper alloy which cannot be damaged by the electric arc.

[0050] The amount of copper on the inner face and possibly at the outer face of the main body is advantageously chosen to optimize the thermal transfer.

[0051] In addition, the circuit breaker according to the invention comprises an element to condense the vaporized copper which is sublimed during opening, in order to reduce dispersion of this vaporized copper in the dielectric gas of the installation.

[0052] As seen in the figures, the internal sleeve 1 is mounted at the extremity of the exhaust tube 13, along which the dielectric gas is evacuated upon opening of the breaker, the circulation of the gas being shown by corresponding arrows on FIGS. 3 and 4.

[0053] This exhaust tube 13 has its extremity opposed to the one carrying the internal sleeve 1 which is electrically connected to another conductive tubular element 22 of the breaker, by means of a connection spacer 23 mounted between the extremities of tubes 13 and 22 and which closes these extremities.

[0054] When the breaker is being opened, the warm dielectric gas heated by the electrical arc A flows longitudinally in the exhaust tube 13, by passing first through the internal sleeve and then through the exhaust tube 13 in order to reach its extremity which is connected to the spacer 23.

[0055] This exhaust tube 13 comprises near its extremity of connection to the spacer 23 longitudinal slots 24, through which the warm dielectric gas is evacuated radially to the internal space of the support 21 which surrounds the tube.

[0056] As illustrated by the arrows, the warm gas uses a path which forms a small angle with longitudinal direction AX, to flow out of the exhaust tube 13, in the direction of the surrounding of the extremity of this tube.

[0057] As seen in FIG. 4, the connecting spacer comprises a first extremity 25 inserted into the free end of the exhaust tube 13, and another extremity 26 inserted in the extremity of the conductive tube 22. This spacer 23 which has a rotationally symmetrical shape also comprises a circular plate 27, having a diameter which is greater than the diameters of the tubes 13 and 22, and which extends perpendicular to direction AX.

[0058] As seen in FIG. 5, the plate 27 carries on its face oriented towards the internal sleeve 1 a collector 28 to which is directed the flow of gas which comes out of the slots 24 of the exhaust tube 13. This gas which is a warm mix of SF6, of vaporized copper and of decomposition products, is directed against the collector 28, to allow condensation of the vaporized copper on this collector 28.

[0059] This collector 28 comprises a support 29 of thermally insulating material such as PTFE (polytetrafluoroethylene) carried by the face of plate 27 which is oriented towards the internal sleeve 1, and a metallic wall 31, here made of steel, which is carried by the free face of this support 29.

[0060] When the conductive wall receives the flow of gas, the vaporized copper condenses onto the conductive wall, ensuring that this vaporized copper does not flow to the other parts of the installation.