Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
  • H01H33/02—Details
  • H01H33/53—Cases; Reservoirs, tanks, piping or valves, for arc-extinguishing fluid; Accessories therefor, e.g. safety arrangements, pressure relief devices
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/02—Bases, casings, or covers
  • H01H2009/0292—Transparent window or opening, e.g. for allowing visual inspection of contact position or contact condition
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H11/00—Apparatus or processes specially adapted for the manufacture of electric switches
  • H01H2011/0081—Apparatus or processes specially adapted for the manufacture of electric switches using double shot moulding, e.g. for forming elastomeric sealing elements on form stable casing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
  • H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
  • H01H33/66—Vacuum switches
  • H01H33/662—Housings or protective screens
  • H01H33/66207—Specific housing details, e.g. sealing, soldering or brazing
  • H01H2033/6623—Details relating to the encasing or the outside layers of the vacuum switch housings

Definitions

• the present invention relates to a high or medium voltage, leaktight electrical switchgear with pressurized insulating gas, comprising in a housing, interrupting contacts capable of occupying an open position and a closed position, and a system for locating the open or closed position of the interrupting contacts from outside the housing.
• thermoplastic for visualization This document describes the production of a transparent window made of thermoplastic material in an opening of an enclosure for electrical equipment. The window is inserted into the opening using a plastic injection molding method, the edge of the opening and the edge of the window being anchored together.
• the object of the invention is to propose a high or medium voltage electrical switchgear, with insulating gas under pressure, for external application which is of a simpler design and of increased reliability by allowing '' have a direct view of the position of the interrupt contacts.
• a rigorous selection of materials must be made to take into account the combined constraints applied to the equipment.
• the subject of the invention is pressure pressuring, of internal pressure greater than atmospheric pressure, generating an outward compression foxce.
• the invention aims to insert a display window for an electrical switchgear.
• the materials must meet the electrical criteria essential for these applications in the field of medium and high voltage, namely good resistance to electrical tracking and erosion.
• the materials used to make the viewing window as well as the methods used to make the junction of the window with the body of the insulator must make it possible to seal the apparatus.
• the admissible annual loss of insulating gas for the whole apparatus being less than or equal to 1%.
• the combination of these selection criteria results in a restriction in the choice of materials available to perform the function.
• the criteria for selecting the materials are clearly established in the invention to allow the production of high or medium voltage electrical switchgear with pressurized insulating gas comprising, in a housing, interrupt contacts capable of occupying a open position and closed position, and a system for locating the open or closed position of the interrupting contacts from outside the housing.
• the subject of the invention is a sealed high or medium voltage electrical switchgear comprising, in a housing, interrupt contacts capable of occupying an open position and a closed position, and a system for locating the open or closed position of the interrupting contacts from outside the housing, the housing being a composite insulator formed by a rigid tube surrounded by an elastomer casing whose external surface defines a succession of annular fins, characterized in that the rigid tube and the elastomeric envelope are arranged to define an at least translucent observation window through which the open or closed position of the interrupting contacts is visible, in that the rigid tube is made of translucent composite material or plastic material at least translucent and in which a transparent window in material filtering ultraviolet radiation or on which a transparent ultraviolet filter is bonded to the rigid tube, this window not being covered by the elastomer envelope and defining the observation window, the rigid tube being formed by assembling tubes, one of the tubes being made of glass or in at least translucent polymer, resistant to ultraviolet, in that all the materials in contact with solar radiation are
• materials in contact with solar radiation should not show signs of degradation, such as cracks, surface deformations (increase in surface roughness) or deterioration of transparency after accelerated aging of 1000 hours.
• materials in contact with solar radiation should not show signs of degradation, such as cracks, surface deformations (increase in surface roughness) or deterioration of transparency after accelerated aging of 1000 hours.
• the polymers which make up the outer casing or the porthole and which are in direct contact with solar radiation should advantageously be chosen from those which do not have no absorption of radiation in the range goose 300 to 400 nm of wavelength, ⁇ c is to say that the chemical structure of these polymers should not contain an aromatic ring
• An electrical switchgear according to the The invention may have the following particularities: the rigid tube is made of an at least translucent plastic material and a section of the envelope surrounding the interrupting contacts is made of an at least translucent elastomer material.
• the translucent section of the envelope is xealized by injection molding of a first elastomeric material and is interposed between two end sections of the envelope which are produced by injection molding of a second elastomeric material more loaded with fillers mineral cjue the first elastomeric material.
• the rigid tube is made of glass and an area of the rigid tube is not covered by the elastomer envelope, this area defining said observation window.
• the rigid tube is made of translucent composite material or of plastic material at least translucent and a transparent porthole made of material filtering ultraviolet radiation is bonded to the rigid tube, this porthole not being covered by the elastomer shell and defining the window d. observation.
• the rigid tube is formed by assembling tubes, one of the tubes being made of glass or of polymer resistant to ultraviolet radiation and not covered by the elastomer envelope defining the observation window.
• An apparatus according to the invention may also have the following particularities: the plastic material at least translucent is made of polymethyl methacrylate (PMMA), polycarbonate (PC), crystal polystyrene (PS), polyvinylidene fluoride (PVDF) or made of cycloaliphatic epoxy resin.
• PMMA polymethyl methacrylate
• PC polycarbonate
• PS crystal polystyrene
• PVDF polyvinylidene fluoride
• the elastomer material is silicone, ethylene-propylene rubber or fluorinated elastomer possibly loaded with mineral fillers.
• the rigid tube contains a dielectric insulation gas.
• the rigid tube is protected inside by deposit of transparent inert material chemically contxes the aggressions of the decomposition products of the
• the rigid tube in direct contact with the atmosphere is made of material resistant to solar radiation (in particular to ultraviolet radiation) or made using a material not resistant to ultraviolet radiation, and protected by a filter.
• Sun Creme a material resistant to solar radiation (in particular to ultraviolet radiation) or made using a material not resistant to ultraviolet radiation, and protected by a filter.
• Sun Creme a material not resistant to ultraviolet radiation
• polycarbonate based on a bisphenol motif and polystyrene containing Aromatic cycles must absolutely be protected from UV by the use of an UV filter or by the addition of an ultraviolet absorbent.
• Polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF) and cycloaliphatic epoxy resin can be used directly in contact with the atmosphere.
• the electrical switching device can be a high or medium voltage line disconnector in which the tube is filled with a dielectric insulating gas such as SF6 under a pressure of 2 to 3 bars.
• a dielectric insulating gas such as SF6 under a pressure of 2 to 3 bars.
• the opening of the interrupting contacts is done without voltage so that the transpaxent plastic tube is not subjected to significant temperatures due to the presence of electric arcs.
• the insulating gas is not ionized by electrical discharges and remains inert for the transparent plastic material of the tube.
• FIG. 1 very schematically illustrates an electrical switchgear according to the invention.
• FIG. 2 very schematically illustrates a second embodiment of an electrical switchgear according to the invention.
• FIG. 3 very schematically illustrates a third embodiment of a electrical switchgear according to the invention.
• FIG. 4 very schematically illustrates a fourth embodiment of an electrical switchgear according to the invention.
• FIG. 5 very schematically illustrates a line disconnector according to the invention.
• Figure 6 illustrates very schematically a line disconnector according to the invention comprising a vacuum interrupter with a viewing window.
• a high or medium voltage electrical switchgear 1 comprises interrupt contacts 2 capable of occupying an open position and a closed position and which are disposed in a composite insulator formed by a rigid tube 3 surrounded by an elastomer envelope 4.
• the interrupting contacts 2 comprise a fixed contact assembly in the tube and a movable contact assembly in the tube.
• the movable contact assembly is arranged in the middle region of the length of the tube as illustrated in FIG. 1.
• the elastomeric shell has an outer surface which defines a succession of annular fins such as 4A, 4B, 4C coaxial distributed along the tube 3 between two metallic end fittings 5, 6 of the composite insulator in which the two ends of the tube 3 are fixed respectively.
• the tube 3 shown has a cylindrical shape
• the invention extends to a tube having another form of revolution, for example a tube in the form of a truncated cone or even in the form of a barrel.
• the rigid tube 3 and the elastomer casing 4 are arranged to define an observation window 7 at least translucent through which the open or closed position of the interrupting contacts 2 (here an open position) is visible.
• the rigid tube 3 is produced by molding a transparent or at least translucent plastic material resistant to ultraviolet radiation, resistant to explosion and having good chemical resistance.
• This plastic material is for example a thermosetting polymer such as the cycloaliphatic epoxy resin crosslinked with a non-aromatic phthalic anhydride of the hexahydrophthalic type (HHPA) or a transparent thermoplastic polymer such as a safety glass made of polymethyl methacrylate (PMMA).
• HHPA non-aromatic phthalic anhydride of the hexahydrophthalic type
• PMMA polymethyl methacrylate
• Such a rigid tube 3, having a wall thickness of approximately 8 mm, can be filled with an electrically insulating gas, in particular SF 6 , under a pressure of approximately 2 to 3 bars.
• the rigid tube 3 can possibly be protected inside, against the aggressions of the decomposition products of SF 6 , by deposition of chemically inert transparent material. This protection can be achieved, for example, by a very thin layer of a few micrometers deposited under vacuum ("CVD", "Sputterinçj” ...) or by a thicker layer of polytetrafluoxoethylene (PTFE) or other fluorinated polymers (PFA, FEP).
• CVD very thin layer of a few micrometers deposited under vacuum
• PTFE polytetrafluoxoethylene
• PFA fluorinated polymers
• the tube can be protected from attack such as ultraviolet radiation by the addition of a UV filter based on the incorporation of an ultraviolet absorbent with an aromatic structure, for example from the family of fc> enzaldehydes.
• a transparent ultraviolet filter of the “Altuglas CN” type sold by the company Altuglas can be used.
• the assembly made up of the rigid tube, the hiublot and the UV filter must be UV-resistant, so that this assembly must not show signs of degradation, such as cracks, surface deformations (increase in surface roughness) or a deterioration in transparency after an accelerated aging of 1000 hours under UV radiation from a xenon arc source or under fluorescent UV lamps according to ISO 4892-2 and ISO 4892-3 standards.
• annular section 8 of the envelope surrounding the interrupting contacts 2 is made of an elastomeric material at least translucent and defines the observation window 7.
• This annular section 8 is a section of the casing which is disposed substantially in the central region of the length of the tube (central region in which the movable contact assembly is arranged) so that it is interposed between two other end sections 9, 10 of the envelope.
• the elastomer forming the envelope must have good mechanical properties, transparency and aging, and be resistant to ultraviolet radiation and abrasion by electric arcs. More particularly, the elastomer must have a tear strength greater than 6 N / mm. The elastomer must resist physicochemical aging and attack by water.
• the dielectric loss factor (tan ⁇ ) of the elastomer must remain below 0.2 after 50 days' immersion in water at 50 ° C.
• the elastomer must not show signs of degradation, such as cracks, surface deformations (increase in surface roughness) or deterioration in transparency after accelerated aging of 1000 hours under radiation.
• UV xenon arc source or UV fluorescent lamps according to ISO 4892-2 and ISO 4892-3 standards.
• the material must be at least class 1A3.5 according to method 1 (criterion A) of standard IEC 60587.
• the elastomers mentioned in the invention for producing the 'casing of electrical equipment does not have an aromatic chemical structure.
• FIG 1 there is shown in hatched lines the two end sections 9, 10 which are produced by injection molding of a first elastomeric material, for example silicone, ethylene-propylene rubber (EPR, EPDM) or fluorinated elastomer (“viton®”), loaded with mineral fillers which can be, for example, alumina, tri-hydrated alumina, titanium oxide or silica.
• EPR ethylene-propylene rubber
• viton® fluorinated elastomer
• mineral fillers which can be, for example, alumina, tri-hydrated alumina, titanium oxide or silica.
• the tri-hydrated alumina particles provide the elastomeric material, as is known to those skilled in the art, with increased resistance to dielectric stresses, but they make the elastomeric material opaque, which is illustrated by the hatched lines.
• the section 8 (shown without hatched lines) is produced by injection molding of a second much less loaded elastomeric material or of a second uncharged elastomeric material so that it remains translucent after molding.
• the rectangle 11 schematically represents an injection mold and the references 12, 13, 14 designate three injection ports for the elastomeric material.
• the injection inlets 12,13,14 are spaced along the tube 3.
• the injection inlet 13 is arranged substantially in the middle of the annular section 8 forming the observation window 7 while the injection inlets 12 and 14 are arranged substantially in the middle of the end sections 9 and 10 respectively.
• the envelope 4 For the formation of the envelope 4 around the transparent tube 3, elastomeric material loaded with alumina particles is injected into the inlets 12 and 14 and at the same time the elastomeric material is weakly or not injected into the inlet 13 loaded.
• the envelope 4 is produced with an annular section 8 at least translucent in the middle part of the envelope.
• the injection inlets 12, 13 and 14 can be offset along the tube 3 and the number of injection inputs can be increased to form the observation window on a selected area of the envelope.
• the injection formation of the envelope 4 around the transparent tube is carried out in two distinct stages.
• the elastomeric material weakly or not loaded with alumina is injected through the inlet 13 to form the observation window 7 on a chosen area of the envelope 8. Then, when the observation window 7 is finished , elastomeric material loaded with alumina particles is injected through the inlets 12 and 14 to form the end sections 9 and 10 respectively of the envelope.
• the deposition of the elastomeric material of the envelope can also be carried out by winding around the rigid tube rather than by injection.
• the system thus produced is waterproof and has an annual leakage rate of the order of or less than 0.5%.
• a 1 "high or medium voltage electrical switchgear comprises a composite insulator formed by a rigid tube 3 'surrounded in part by an elastomer casing 4', a part not surrounded by this casing 4 'serving as observation window 7' of the interrupting contacts 2 '
• the rigid tube 3' is made of glass which can be protected inside, against attack by the decomposition products of SF 6.
• the glass being resistant in abrasion by electric arc, the glass surface defining the observation window 7 ′ does not need to be surrounded by an elastomer envelope.
• the envelope 4 ′ of elastomer loaded with mineral fillers partially covering the rigid tube 3 can be formed either by injection or by extrusion (winding).
• adhesion primer a precursor chemical called adhesion primer.
• This precursor is generally a complex compound of silanes (Si-R 4 ), for example of epoxy silanes and of solvents.
• Si-R 4 silanes
• a process is followed which consists in using a mask to prevent the deposition of adhesion primer on the window area, then in depositing the elastomer on the entire surface of the tube rigid and finally to remove the elastomer from the window area and to clean the observation window with alcohol.
• the adhesion of the elastomer to the window area can be further reduced by depositing on this area a surfactant or fatty product before the deposition of the elastomer.
• Another solution consists in depositing a foam mask in the injection mold, for example intended to prevent the deposition of the elastomer in the viewing area.
• an electrical switchgear 1 '' high or medium voltage comprises a composite insulator formed by a rigid tube 3 '' partially covered by an elastomer casing 4 '' loaded with mineral charges, the part not covered by this 4 '' envelope serving as a 7 '' observation window for 2 '' interrupt contacts.
• the rigid tube 3 '' is made either of translucent composite material, composed of mineral fibers, possibly braided, inserted in a thermosetting polymer, or of plastic material at least translucent such as those presented for the rigid tube 3 of Figure 1. L the interior of the tube can be optionally protected against attack by the decomposition products of SF 6 .
• On the rigid 3 '' tube is a porthole
• This 15 '' at least translucent capable of filtering out ultraviolet radiation intended to serve as an observation window.
• This 15 '' porthole can be made of glass, possibly doped to better filter out ultraviolet radiation, or alternatively of translucent polymer, such as for example "Makrolon”, “Altuglas", polystyrene or PVDF, stabilized to resist radiation ultraviolet or covered with a UV filter.
• the 15 '' porthole is glued to the rigid 3 '' tube using a transparent epoxy, polyacrylate or silicone adhesive, possibly with prior machining of the 3 '' tube.
• FIG. 4 shows another embodiment of a 1 '''high or medium voltage electrical switchgear according to the invention comprising a composite insulator formed by a rigid 3''tube * partly surrounded by a 4 '''elastomer casing, a part not surrounded by this 4''' casing serving as a viewing window 7 '''of interrupt contacts 2' 1 '.
• the rigid 3''tube' is made in several parts.
• an insert tube 3''' a made of at least translucent material, glass or polymer resistant to ultraviolet radiation, is assembled between two tubes 3 '''b,3'''c for example in composite material, composed of mineral fibers, possibly braided, inserted in a thermosetting polymer such as polyurethane or epoxy. These elements rigid tube component 3 "'are glued or screwed and glued.
• the insert serves as a viewing window 7' and 11 is left uncovered by the envelope forming elastomer by the method described for Figure 2
• the elastomer covers the edges of the insert in order to ensure the leaktightness and insulation of the apparatus.
• the system thus produced is leaktight and has an annual leakage rate of around of or less than 0.5%.
• FIG. 5 an example of use has been illustrated with a line disconnector such as 1 in FIG. 1 according to the invention which is mounted in series with a circuit breaker 20 in a porcelain envelope for example, the switchgear assembly switchgear 1 used as a disconnector and circuit breaker 20 being mounted on the ground on a porcelain support insulator 21.
• the current I is first cut by the circuit breaker 20, the electrical switchgear 1 uses as a disconnector then being opened. Consequently, the transparent disconnector tube 3 is generally not subjected to the effects of electric arcs.
• the system thus produced is waterproof and has an annual leakage rate of the order of or less than 0.5%.
• FIG. 6 an example of use has been illustrated with a line disconnector such as that referenced 1 in FIG.
• the electrical switchgear assembly 1 used as a disconnector and circuit breaker 20 being mounted on the ground on a porcelain support insulator 21.
• the current 1 is first cut off by the circuit breaker 20, the electrical switchgear 1 uses as a disconnector then being opened. Consequently, the transparent disconnector tube 3 is generally not subjected to the effects of electric arcs.
• the system thus produced is waterproof and has an annual leakage rate of the order of or less than 0.5%.
• a disconnector according to the invention can also be installed in a V configuration with a circuit breaker or even in a U configuration, the base of the U being constituted by the circuit breaker and the two branches of the U being each constituted by a disconnector conforming to the invention.
• An electrical switchgear according to the invention has the advantage of being simple to manufacture and of having a system for direct identification of the position of the interrupting contacts.
• An electrical switchgear according to the invention could consist of a circuit breaker insofar as the plastic material of the tube is adapted to the attacks of electric arcs and is sufficiently resistant to pressures higher than 6 bars.

Landscapes

• Gas-Insulated Switchgears (AREA)
• Insulators (AREA)
• High-Tension Arc-Extinguishing Switches Without Spraying Means (AREA)
• Switch Cases, Indication, And Locking (AREA)
• Circuit Breakers (AREA)
• Organic Insulating Materials (AREA)
• Testing Relating To Insulation (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=34944423

Family Applications (1)

Country Status (7)

Families Citing this family (12)

Family Cites Families (10)

• 2004
  • 2004-04-07 FR FR0450697A patent/FR2868875B1/fr not_active Expired - Fee Related
• 2005
  • 2005-04-07 DE DE602005017756T patent/DE602005017756D1/de active Active
  • 2005-04-07 EP EP05748638A patent/EP1733409B1/de not_active Not-in-force
  • 2005-04-07 US US11/547,456 patent/US7989726B2/en not_active Expired - Fee Related
  • 2005-04-07 WO PCT/FR2005/050213 patent/WO2005101438A2/fr active Application Filing
  • 2005-04-07 AT AT05748638T patent/ATE449414T1/de active
  • 2005-04-07 CN CNB2005800120163A patent/CN100573766C/zh not_active Expired - Fee Related

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events