FR3008540A1 - HIGH VOLTAGE CIRCUIT BREAKERS, IN PARTICULAR ARC ROTATING - Google Patents

Abstract

The invention relates to a circuit-breaker device, comprising: a first contact (11) and a second contact (12), one of which is mobile with respect to the other, each contact having a central opening extended by a channel (35); , 45) allowing the escape of a part of the gases produced during an arc, the exhaust gas channel of one of them being provided with means (21, 23) to allow a passage of gas from the expansion chamber (19) to an exhaust chamber (14, 15) while limiting or preventing the return of these same gases to the expansion chamber (19).

Description

TECHNICAL FIELD The invention relates to high voltage and medium voltage circuit breakers. It applies particularly advantageously to circuit breaker devices operating at high voltage, rotating arc. More specifically, the invention relates to a gas-insulated breaker chamber of the "live tank", "dead tank" or "GIS" type. Each of EP 0932176 or FR 2617633 discloses a breaking chamber for self-expanding circuit breaker and rotating arc. This chamber uses two so-called permanent contacts, at least one of which is mobile along the axis of the system, and, in addition, two so-called arcing contacts, at least one of which is also mobile. This type of structure is complex. In addition, the solution adopted for the integration of magnetic means is also complex. The set is large, difficult to achieve. To overcome these drawbacks, it is sought to provide a less bulky device and simpler to achieve.

SUMMARY OF THE INVENTION To this end, the invention proposes a circuit breaker device, comprising: a first contact and a second contact, one of which is mobile relative to the other, each contact having a central opening extended by a channel allowing the escape of a part of the gases produced during an arc, the exhaust gas channel of one of them being provided with means to allow a passage of gases from the chamber of expansion to an exhaust chamber, while limiting or prohibiting the return of these same gases to the expansion chamber. The only two arcing contacts provided are hollow in order to ensure the evacuation of the cutoff gases to exhaust volumes. In addition, such a device does not include a blowing nozzle. In one embodiment, the channel 20 for exhausting gases from at least one of the contacts comprises a tube that enters said exhaust chamber. The exhaust gas channel of a fixed contact may comprise means forming a unidirectional valve 25 allowing a passage of gases from the expansion chamber to the exhaust chamber of the fixed contact, while prohibiting the return of these gases towards the expansion chamber. Alternatively, the gas escape channel of a fixed contact comprises means allowing the gases to pass from the expansion chamber to the exhaust chamber of the fixed contact, while limiting the return of these gases to the chamber. expansion. For example, these means comprise a cone whose apex is directed towards the escape channel of the fixed contact. Such a circuit breaker device, according to one of the embodiments set out above, may comprise means allowing a gas inlet to the expansion chamber and from an exhaust chamber or a compression chamber. It may further comprise means forming a unidirectional valve allowing a passage of gas from the exhaust chamber of a fixed contact to the expansion chamber.

According to one embodiment, the exhaust gas channel of a movable contact comprises a tube which penetrates into said exhaust chamber and which is provided with at least one lateral orifice. Advantageously, the position of the lateral orifice is such that it closes during an opening stroke of the circuit breaker device by crossing the wall of the movable contact holder, preventing communication through this orifice between the channel and the chamber. expansion, for example 5 to 15 ms after the separation of the contacts. Advantageously, a wall being associated with the movable contact, which defines a compression chamber and let part of a gas, when it is contained in the compression chamber, to the expansion chamber.

At least one of the fixed or movable contacts may comprise: at least one slot oriented in a direction inclined with respect to the longitudinal axis AA 'of the device, and / or at least one magnetic means for rotating a part of the electric arc formed during the opening of the contacts. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a diagram illustrating a device according to the invention, with a movable contact and a fixed contact in the open position. Figures 1B and 1C show details of making the fixed contact and the moving contact. Figure 2 is a diagram illustrating a device according to the invention, with a movable contact and a fixed contact in the closed position. FIG. 3 is a diagram illustrating a variant of a device according to the invention, with a movable contact and a fixed contact in the closed position. FIG. 4 is a diagram illustrating another variant of a device according to the invention, with a movable contact and a fixed contact in the closed position. Figure 5 is a diagram that illustrates yet another variant of a device according to the invention, with a movable contact and a fixed contact in the closed position.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS A first embodiment of the invention will be given in connection with FIG. 1A. In this figure, there is shown a circuit breaker 9, gas-insulated (SF6) or other gas. It comprises a chamber insulator 20 inside which is housed a cutoff mechanism 10. This cutoff mechanism 10 could just as easily be incorporated in a tank at the earth potential. The latter comprises a fixed arcing contact 11 mounted on one end or a wall 17a of a fixed contact holder 17 and a movable arcing contact 12 mounted on one end or a wall 18a of a movable contact carrier 15. The fixed contact holder 17 and the movable contact holder 18 will be described below, but have an outer surface of which a portion is in the form of a cylinder, inserted into the inner cylindrical cavity of the insulator 20, of longitudinal axis AA '. Unlike some known devices, the one shown here does not have a double set of contacts. Usually, circuit breaker systems are provided with so-called permanent ones, at least one of which is the axis of the system, and, in addition, two arcing contacts of which, again, at least in fact the two movable contacts according to said contacts. one is mobile along the axis of the system. In this type of known system, the permanent contacts are, when opening the contact, open before the arcing contacts. Here, only two contacts are provided, at least one of which is movable relative to the other. No "permanent" contact is expected. An insulating tube 16, of longitudinal axis AA ', is mounted in a gastight manner, on the one hand against or against the fixed contact holder 17 and on the other hand on or against the movable contact holder 18. This tube 16 is for example chosen from the following materials: such as PPS (polyphenylene sulphide), PEEK (polyetheretherketone), PTFE (polytetrafluoroethylene), glass-ceramic (MACOR) or agglomerated mica (mica or mica muscovite or mica phlogopite ). As a non-limiting variant, the PPS or the PEEK can also be loaded, for example with mica.

For example, the periphery of a portion of each of the walls 17a and 18a bears against the inner surface of this insulating tube 16. The latter delimits radially, with the contact holders 17, 18, an automatic chamber. Expansion 19 (or a thermal volume) in which the arcing contacts 11 and 12 are arranged opposite each other. At least one of these contacts is slidably movable in the bore of the corresponding contact carrier. According to one embodiment, the fixed contact holder 17 may have the shape shown in FIG. 1B, with an end 171 of substantially cylindrical shape, of outside diameter D1, and traversed, along the longitudinal axis AA ', by a bore 171 , of diameter D2, less than D1, in which a portion 31 of the contact is inserted. The outside diameter D1 is substantially close to the inside diameter of the tube 16. This end 171 is extended by a substantially cylindrical body 172 of outside diameter D2 greater than D1. This body is inserted into the inner channel of the chamber insulator. The insulating tube 16 can bear against the outer surface of the end 171, and possibly bear against the end surface 172 'left free between this outer surface and the outer surface of the body 172. The movable contact carrier 18 may have the shape shown in Figure 1C, with an end 181 of substantially cylindrical shape, outer diameter Dl, and traversed, along the longitudinal axis AA ', a bore 181', of diameter D2, less than Dl, in which part 41 of the contact is inserted. The outside diameter D1 is substantially close to the inside diameter of the tube 16. This end 181 is extended by a substantially cylindrical body 182 of outside diameter D2 greater than D1. This body is inserted into the inner channel of the chamber insulator. The insulating tube 16 can bear against the outer surface of the end 181, and possibly bear against the end surface 182 'left free between this outer surface and the outer surface of the body 182.

Hoods 161 and 163 are respectively disposed on the fixed contact door 17 and the movable contact holder 18 so as to limit the peak effect.

In variant not shown, particularly in the case of an AIS type circuit breaker (air insulated switchgear), the insulating tube 16 is absent. In this case, it is preferable to provide on the inner surface of the chamber insulator 20 a protection against electric arcs, for example a sheet of Teflon. Other aspects of an embodiment of the fixed arcing contact 11 are also shown in FIG. 1B.

In this figure, this fixed contact has a portion 30, cylindrical and hollow, disposed along the axis AA 'of the device. It has a first outside diameter dl. It is formed at the end of a tubular portion 31 having a second outer diameter d2, less than dl. The portion 30 is said to be in the form of a section. This type of contact is therefore called "in section". In a variant not shown, the arc contact 11 comprises petals, that is to say projections which extend radially from a central portion, transversely to the axis AA '. Advantageously, these petals are inclined or curved in the same radial plane, about the axis AA '. A substantially cylindrical channel 35 extends in these two portions along the axis AA 'of the system.

A ring-shaped stiffener part 33, also of substantially cylindrical shape, may be disposed in the portion 30, its axis coinciding with that AA 'of the device.

The outer wall of the portion 30 and the stiffener 33 delimit between them an annular cavity 32. The inner wall of the portion 30 constitutes a portion of the wall of the channel 35. A pellet 34, in the form of a crown, may be fixed on the face, turned towards the other contact, of the portion 30. This pellet closes the annular cavity 32 but its central perforation leaves free access to the inlet of the channel 35. Here, the pellet 34 is assembled to the portion 30 by soldering under vacuum.

The channel 35 forms a gas exhaust duct. It is here of constant internal diameter, and is formed jointly by the tubular portion 31, by the stiffener 33 and by the central perforation of the pellet 34.

The channel 35 of the contact 11 brings in fluid communication with an exhaust chamber 14, isolated from the chamber 19 by the wall 17a of the contact carrier. This exhaust chamber 14 may have a cylindrical portion 143 extended by a conical portion 142 formed by the inner surface of the contact holder 17a. The exhaust chamber 14 extends longitudinally, for example to a not shown bottom wall. At the end of the fixed arc contact 11, at the end of the channel 35 which is turned towards the exhaust chamber 14, is disposed a unidirectional or non-return valve 50 (or a unidirectional or non-return valve) . This valve 50 can be opened under the pressure of the cutoff gases coming from the chamber 19, after opening of the contact: it then allows the evacuation of the cutoff gases to the chamber 14. It can not be opened in the opposite direction, c That is, to allow a flow of gas from the chamber 14 to the chamber 19. This valve 50, provided at the interface between the conduit 35 of the fixed contact 11 and the exhaust chamber 14, therefore allows the evacuation of the cutoff gases from the duct 35 to the chamber 14 but prevents their return into the duct 35. In FIGS. 1A and 1B, this valve is shown provided with a spring 51 which comes to apply the valve 50 against the end duct 35, opposite to the fixed contact. The valve 50 opens when the pressure exerted by the spring becomes lower than the pressure of the gases coming from the chamber 19. The movable arcing contact 12 can be structured in a manner similar to the fixed arcing contact 11 with, however, some differences. An embodiment is shown in Figure 1C. The arc contact 12 has a portion 40, cylindrical and hollow, disposed along the axis AA 'of the device. It has a first outside diameter of 1. It is formed at the end of a tubular portion 41 having a second outer diameter of 2, less than 1. The portion 40 is said to be in the form of a section. This type of contact is therefore also called "in section".

In a variant not shown, the arc contact 12 comprises petal projections as described with reference to the contact 11. A channel 45 of substantially cylindrical shape extends in these two portions, along the axis AA 'of the system. A piece 43, forming a stiffener, of annular shape, also of substantially cylindrical shape, may be disposed in the portion 40, its axis coinciding with that AA 'of the device. The outer wall of the portion 40 and the stiffener 43 delimit between them an annular cavity 42. The inner wall of the portion 40 constitutes a portion of the wall of the channel 45. A crown-shaped pellet 44 may be fixed on the face, facing the other contact, of the end portion 40. This pellet closes the annular cavity 42 but its central perforation leaves free access to the inlet of the channel 45. Here, the pellet 44 20 is assembled to the portion 40 by vacuum brazing. The channel 45 forms a gas exhaust duct. It is here of constant internal diameter, and is formed jointly by the tubular portion 41, the stiffener 43 and the central perforation 25 of the pellet 44. The channel 45 of the contact 12 brings in fluid communication with an exhaust chamber 15 isolated from the chamber 19 by the wall 18a of the contact carrier. This exhaust chamber 15 may have a cylindrical portion 153 extended by a conical portion 152 formed by the interior surface of the contact carrier 18a. The exhaust chamber 15 is extended longitudinally, for example up to a bottom wall not shown through a cutoff rod 22 (Figure 1) of the movable contact 12. The exhaust chamber 15 for example communicates with the internal volume of a carrier insulator (not shown) on which the insulator chamber 20. However, the presence of the carrier insulator is not a limiting aspect.

The movable arcing contact 12 is slidably mounted through its contact holder 18. For this purpose, it is provided with one or more bearings 21. The tubular portion 41 associated with the movable arcing contact 12 is longer than that of the channel associated with the fixed arcing contact 11, in order to facilitate the stroke of the movable contact 12 when opening the breaking mechanism 10. Preferably, one or more lateral holes 47 are provided in the conduit 45 of the movable contact to optimize the pressure rise of the expansion chamber and the operation of the gases from the expansion chamber 19. When extinguishing an arc, a part of the cutoff gases is discharged through the conduit 35 (Associated with the fixed contact 11), and part of the cutoff gas is discharged through the conduit 45 (associated with the movable contact 12), then, optionally, through the lateral orifices 47 formed therein. Spring means 13 (FIG. 1A) are arranged in the chamber 15, here in the insulator 20. These means make it possible to force the contact between the arcing contacts 11 and 12 to bring them into the closed position. Alternatively the movable contact may be provided with a washer or wall 120, shown in broken lines in Figure 1C. This washer 120 is carried by the movable contact 12, behind it with respect to the face of the movable contact facing the other contact 11. It is pierced to be arranged around a section of the tubular portion 41. The washer 120 is of smaller diameter than the inner surface 160 of the tube 16, leaving at least a gap 121 for the passage of gas between the washer 120 and the tube 16 and / or through the washer 120 itself.

Upon opening of the mechanism 10, the movable contact 12 moves from its closed position, shown in FIG. 2, to its open position, illustrated in FIG. 1A, compressing the gas contained in the chamber 410. part of the fresh gases contained in the volume 410 through the gap 121 to the rest of the chamber 19, because of the recoil movement of the movable contact 12, and therefore of the washer 120, towards the movable contact holder 18.

This washer 120 defines, with the front face or the wall 18a of the movable contact carrier 18 and with the inner surface of the insulating tube 16, a compression chamber 410 (see Figure 2). The washer 120 thus forms a piston for the compression of this chamber 410, making it possible to obtain an arc blowing pressure that is even greater than the previous solution. In a variant that is not shown, the washer 120 is injected, or else made in two parts that are fixed together to the assembly of the cut-off mechanism. According to this solution, the chamber 410 is made in the chamber 19 itself. it is partly delimited by the inner surface 160 of the insulating tube 16 itself. And it is located in front of the mobile contact door 18, which allows to gain even more compactness. When the mechanism 10 is in the closed state (this is the situation shown in FIG. 2), that is to say when current flows through it, the pads 34, 44 of the arcing contacts 11 and 12 are in contact, preferably plane, against each other. The spring 13 opposes the electrodynamic repulsion forces and ensures good contact between the fixed contact 11 and the movable contact 12 for the passage of the nominal current. During an opening order of the circuit breaker, transmitted by a mechanism such as a rod or rod connected to a free end of the movable contact 12, it separates from the fixed contact 11, to arrive in the position shown in Figure 1A. During opening, an electric arc is then formed between the two pellets 34, 44. This arc exchanges energy with the volume of surrounding gas, which causes a rise in pressure of the gas contained in the car chamber. 19. When approaching a current zero, the pressure generated is used to blow the arc and causes the breaking gases to escape through the conduits 35, 45 to the exhaust chambers 14 and 15.

One or more slots 36, 46 may be provided in the end portion 30, 40 of at least one of the contacts 11 or 12. As can be seen in FIGS. 1B, 1C, each slot 36 may be oriented inclined by relative to the axis AA 'of the device. Preferably, each slot 36 is thus oriented to force the flow of current in a direction that is non-axial, here, slightly at an angle from the pellets 34, 44 and outwards.

The positioning of these slots 36, 46 is such that the passage of the current in the contacts 11 and 12 generates a magnetic field with a radial component that generates an orthoradial force on the electric arc, forcing it to rotate, which contributes to its blowing. An example of orthoradial force F depending on the direction of the current I and the magnetic field B is shown schematically in FIG. 1B. In another embodiment, shown in FIG. 3, the tubular portion 31 of the fixed contact 11 is extended by a tube 310 in the exhaust chamber 14, beyond the wall 17a. A certain volume of fresh gas is available between this tube 310 and the fixed contact holder 17. At least one unidirectional valve 173, 173 'can then be provided through the wall 17a, to inject a part of the volume of fresh gas into the chamber 19 when the cutoff gases enter the exhaust chamber 14. This injection of gas into the chamber 19 can lower the temperature in the cutoff zone and better resorb the arc. In FIG. 3, the system is shown in the closed state of the contacts. The other references, common with those of FIG. 1A -1C and 2, designate the same elements therein. This embodiment can be combined with the other elements already described above (for example the slots 36, 46 for rotating the arc and / or the presence of a washer 120 on the moving contact). In another embodiment, shown in FIG. 4, a washer 120, of the type described with reference to FIG. 1C, is carried by the movable contact 12, behind it with respect to the face facing the Another contact 11. In FIG. 4 is also shown, instead of the valve 50, 51 of FIGS. 1A and 2, a fixed insulating cone 140, disposed at the outlet of the channel 35. The axis 20 of this cone is aligned with the AA 'axis of the device, the apex of this cone being directed towards the channel 35. Its large base 140' is turned towards the cylindrical portion of the chamber 14. This cone is connected to the wall 31 by one or more retaining rods 141 The volume delimited by this cone and the inner surface 142 of the contact carrier 17a decreases from the outlet of the channel 35 to the passage defined between the large base of the cone and the cylindrical wall 143 or the wall 142, of shape. it is also conical. In other words, the apex angle of the cone 140 is greater than the angle defined at the top by the conical wall 142. This shape ensures a passage of the gases from the chamber 19 and a restriction or limitation of their possible return 19. FIG. 5 shows an embodiment combining a washer 120 of the type described with reference to FIG. 1C, and with a fixed contact 11 provided with a tube 310 which extends it towards the cavity 14, a valve 173 disposed through the wall 17a as explained above with reference to Figure 3. In this figure the cut-off mechanism 10 is shown closed.

Claims (13)

REVENDICATIONS1. Circuit breaker device, comprising: - a first contact (11) and a second contact (12), one of which is mobile relative to the other, each contact having a central opening extended by a channel (35, 45) allowing exhausting a portion of the gases produced during an arc, 10 - the exhaust gas channel of one of them being provided with means (50, 51, 140, 310) to allow passage gases from the expansion chamber (19) to an exhaust chamber (14, 15) while limiting or preventing the return of these same gases to the expansion chamber (19). The circuit breaker device according to claim 1, the gas exhaust channel of at least one of the contacts having a tube (41, 310) which enters said exhaust chamber (14, 15). 3. circuit breaker device according to one of claims 1 or 2, one of the two contacts being a fixed contact, the gas escape channel of the fixed contact having means forming a unidirectional valve (50, 51) allowing a passing gases from the expansion chamber (19) to the exhaust chamber (14) of the fixed contact, while prohibiting the return of these gases to the expansion chamber (19). 4. circuit breaker device according to one of claims 1 to 2, one of the two contacts being a fixed contact, the gas contact exhaust channel of the fixed contact comprising means (140) allowing a passage of gases from the chamber of expansion (19) to the exhaust chamber (14) of the fixed contact, while limiting the return of these gases to the expansion chamber (19). 5. circuit breaker device according to claim 4, the means (140) allowing a passage of gases from the expansion chamber (19) to the chamber (14) of the exhaust of the fixed contact, while limiting the return of these gases to the expansion chamber (19) having a cone (140) whose apex is directed towards the outlet channel (35) of the fixed contact (11). 6. circuit breaker device according to one of claims 1 to 2, further comprising means for a gas inlet to the expansion chamber (19) from the chamber (14) exhaust. 25 7. circuit breaker device according to claim 6, further comprising means (173) forming a unidirectional valve allowing a passage of gas from the exhaust chamber (14) of a fixed contact to the expansion chamber (19). 30 8. circuit breaker device according to one of claims 1 to 7, one of the two contacts being a movable contact, the gas escape channel of the movable contact comprising a tube (41) which enters the chamber (15) of exhaust and which is provided with at least one lateral orifice (47) communicating the channel (45) with the expansion chamber (19) 9. circuit breaker device according to claim 8, wherein the position of the at least one orifice 47 is such that it is closed during an opening race of the circuit breaker device by crossing the wall (18a) of the movable contact holder, preventing communication through these orifices 47 between the channel (45) and the expansion chamber (19). 10. circuit breaker device according to the preceding claim, wherein the position of the at least one orifice 47 is such that it is closed 5 to 15 ms after the separation of the contacts (11, 12). 11. circuit breaker device according to one of claims 1 to 10, a wall (120) being associated with the movable contact (12), this wall for delimiting a chamber (410) of compression and let part of a gas when contained in this compression chamber (410) to the expansion chamber (19). Circuit-breaker device according to one of Claims 1 to 11, at least one of the fixed or movable contacts (11, 12) comprising at least one slot (36, 46) oriented in a direction inclined with respect to the longitudinal axis ( AZ ') of the device. 13. circuit breaker device according to one of claims 1 to 12, at least one of the fixed or movable contacts having magnetic means for rotating a portion of the electric arc formed when opening contacts.