Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02B—BOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER
  • H02B13/00—Arrangement of switchgear in which switches are enclosed in, or structurally associated with, a casing, e.g. cubicle
  • H02B13/02—Arrangement of switchgear in which switches are enclosed in, or structurally associated with, a casing, e.g. cubicle with metal casing
  • H02B13/035—Gas-insulated switchgear
  • H02B13/0358—Connections to in or out conductors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B17/00—Insulators or insulating bodies characterised by their form
  • H01B17/42—Means for obtaining improved distribution of voltage; Protection against arc discharges
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B7/00—Insulated conductors or cables characterised by their form
  • H01B7/02—Disposition of insulation
  • H01B7/0291—Disposition of insulation comprising two or more layers of insulation having different electrical properties

Definitions

• the invention relates to a high-voltage device and a method for increasing the dielectric strength in a high-voltage device, the high-voltage device having an encapsulating housing and at least one bushing for at least one electrical conductor into the encapsulating housing and/or out of the encapsulating housing.
• High-voltage devices are designed for voltages in a two-digit kilovolt range up to a voltage range of a few hundred kilovolts, in particular 1200 kV, and for currents in the range of up to a few hundred kiloamperes.
• High voltage devices include e.g. B. High-voltage circuit breakers, isolators, transformers, arresters, instrument transformers and/or bushings.
• High-voltage devices, especially circuit breakers are z. B. designed as an outdoor and / or as a gas-insulated circuit breaker, d.
• H. Gas-insulated switchgears which as a live tank, i. H. at high voltage potential, with a switching unit arranged in an insulator, or as a dead tank, i. H. arranged with a switching unit in a grounded housing.
• Dead-tank gas-insulated circuit breakers have an encapsulating z. B. made of aluminum, which is designed in particular in the form of a cylindrical tank, and bushings for electrical conductors to connect switching units, which are arranged inside the encapsulating housing, with power consumers, power generators and / or power lines of a power grid.
• the electrical conductors are current-carrying conductors, e.g. B. with a closed circuit breaker and applied high voltage.
• the encapsulation housing in particular in the form of a kettle, is designed to be gas-tight, with e.g. B.
• the electrical conductors run, starting from the external connection lugs at a gas-tight sealed end of the insulators, to the openings in the encapsulating housing and through to z.
• the switching unit for the electrical connection of the switching unit to power consumers, power generators and/or power lines of the power grid.
• the encapsulating housing of the high-voltage device in particular of the circuit breaker, is arranged on a support, eg. B. on steel struts, which are anchored in a mechanically stable manner in particular in a concrete foundation.
• the enclosure housing is electrically grounded to minimize hazards to service personnel and/or bystanders.
• I insulators in particular in the form of elongated hollow cylinders, are arranged or mounted on one side of the encapsulating housing. fastened opposite the side of the wearer and have e.g. B. perpendicularly or at an angle away from the encapsulation housing, in particular upwards away from the encapsulation housing.
• connection lugs there is a sufficient electrically isolating distance between the connection lugs and the ground potential and/or foundation in order to prevent electrical flashovers.
• encapsulating housing and the insulators are filled with an insulating and/or switching gas, in particular SF 6 .
• the I insulating gas isolates z. B the switching unit and the electrical or current-carrying conductor inside the high-voltage device opposite the grounded encapsulation housing.
• the electrical conductors are arranged equidistantly from the encapsulating housing, in particular perpendicularly penetrating the circular plane of the openings in the center of the circle.
• the openings have a size or scope which, depending on the maximum voltage of the high-voltage device and the insulating gas used and its pressure, ensures sufficient dielectric strength to reliably prevent electrical flashovers between the conductor and the encapsulating housing.
• Electric fields or field peaks in the area of the openings are arranged inside the insulator by grounded electrodes, in particular circular, hollow-cylindrical metal electrodes and mechanically fastened to the flange of the encapsulating housing, starting from the current-carrying conductor changed or reduced, ie shielded.
• grounded electrodes in particular circular, hollow-cylindrical metal electrodes and mechanically fastened to the flange of the encapsulating housing, starting from the current-carrying conductor changed or reduced, ie shielded.
• High voltage levels of the high-voltage device require, for permanent, safe operation, large diameters of the openings in the encapsulating housing, which is associated with high costs for large-scale insulators, require switching gases with high dielectric strength, in particular SF 6 , and/or high pressures of the switching gases, which is associated with high costs for large wall thicknesses of the insulators and encapsulation housings in order to ensure sufficient mechanical stability over the long term.
• switching gases such as B. SF 6 are harmful to the climate.
• Alternative switching gases such as B. Clean Air, ie cleaned air, have a lower dielectric strength.
• the use of climate-friendly switching gases, e.g. B. of clean air thus requires larger ⁇ f f Vietnamese Switches Diameter of the openings in the encapsulating housing and / or higher pressures of the switching gas, with the disadvantages described above.
• Measures such as B. the use of grounded control electrodes increases the dielectric strength only to an extent that is not sufficient for certain voltage levels. This restricts the use of high-voltage circuit breakers.
• the object of the present invention is to specify a high-voltage device and a method for increasing the dielectric strength in a high-voltage device which solve the problems described above.
• it is the task of specifying a high-voltage device which enables high voltage levels to be used in a cost-effective and material-saving manner, especially when using alternative switching gases such as e.g. B. of clean air, with high dielectric strength in the area of bushings of the high-voltage device, especially when using switching gases with low gas pressures, e.g. B. in the area of the ambient air, and/or with diameters of the bushings in the range of bushings in high-voltage devices filled with SF 6 or smaller.
• alternative switching gases such as e.g. B. of clean air
• the specified object is achieved according to the invention by a high-voltage device having the features according to patent claim 1 and/or by a method for increasing the dielectric strength in a high-voltage device, in particular a high-voltage device described above, according to patent claim 14 .
• Advantageous refinements of the high-voltage device according to the invention and/or the method according to the invention for increasing the dielectric strength in a high-voltage device, in particular a high-voltage device described above, are specified in the dependent claims. Objects of the main claims can be combined with one another and with features of the subclaims, and features of the subclaims can be combined with one another.
• a high-voltage device comprises an encapsulating housing and at least one bushing for at least one electrical conductor.
• the at least one electrical conductor is coated with an insulating layer.
• the insulating layer enables the use of bushings with a small diameter, especially when using climate-friendly switching gases, such as e.g. B. Clean Air, in exchange for climate-damaging switching gases, such as e.g. B. SF6 .
• the high-voltage device with at least one electrical conductor, which is coated with an insulation layer, is thus designed to be cost-effective and material-saving, in particular due to the possibility of using bushings with a small diameter, especially when using climate-friendly switching gases such.
• B. Clean Air and enables the use of switching gases with low gas pressures, e .g . B. in the area of the ambient air, which allows encapsulation housings and insulators with low wall thicknesses, at high voltage levels, with high dielectric strength in the area of the bushings of the high-voltage device.
• the highest field strength occurs on the surface of the electrical conductor.
• the insulating layer applied to the electrical conductor creates a layered dielectric, which lowers the point of otherwise highest field strength on the surface of the electrical conductor and, with an optimally selected insulating layer thickness, the electrical field strength in the critical area is approximately evened out.
• the insulation layer also reduces the probability of free strong electrons initiating an electrical breakdown. Local field increases due to surface roughness are reduced or prevented. As a result, the reliability and service life of the high-voltage device is increased, and maintenance intervals can be reduced, which means that personnel and costs are reduced.
• the at least one electrical conductor can be completely coated with an insulating layer along its length. Insulation completely along the length of the electrical conductor has the advantages described above, not only in the area of the bushing, but along the entire conductor.
• the at least one electrical conductor can be coated with an insulating layer exclusively in the area of the leadthrough, in particular in the area of an opening in the encapsulating housing.
• material and costs are saved in comparison with a complete coating, and a targeted, advantageous influencing of the electric field in the area of the bushing is possible.
• flashovers in the bushing area can be reduced or prevented. be prevented, and the dielectric strength, especially in the implementation or. an opening in the encapsulating housing can be increased, with the area being a particularly critical area in terms of field strength and flashover or represents short-circuit probability.
• the insulating layer can have a relative permittivity in the range of 1, in particular greater than 1.
• the insulating layer applied to the electrical conductor whose relative permittivity is slightly greater than that of gas, i.e. greater than 1, creates a layered dielectric, which lowers the point of the otherwise highest field strength on the surface of the especially metallic inner conductor and at an optimal selected insulation layer thickness, the electric field strength in the critical area is approximately evened out.
• the field strength can be adjusted in such a way that the electric field strength at the metallic inner conductor, i.e. H . on the electrical conductor and on the surface of the applied insulating layer are identical.
• the insulating layer can consist of more than one layer, in particular with decreasing permittivity from layer to layer, in particular with the highest permittivity of the layer directly in connection with the at least one electrical conductor.
• the insulating layer can be made of silicone, Teflon, PTFE and/or PCTFE and/or can include silicone, Teflon, PTFE and/or PCTFE. These materials are inexpensive, easy to process, easy to apply in particular as a layer, with a permittivity greater than 1, electrically insulating and therefore well suited as an insulating layer.
• the insulating layer can be formed with a layer thickness in the range of millimeters and/or in the range of centimeters. In the case of several layers, a layer thickness in the millimeter range is particularly good electrical insulation, with a total layer thickness being able to be in the centimeter range. Depending on the material, layer thicknesses in the millimeter or centimeter range are sufficient to achieve the desired effect, with the advantages described above.
• the thickness and the dielectric permittivity of the insulating layer can be selected such that the field strength on the surface of the electrical conductor, particularly in uncoated areas, and on the outer surface of the insulating layer are the same size. As a result, flashovers through the insulating layer and between the conductor and the insulating layer are minimized or eliminated. locked out .
• the encapsulating housing can have a flange and an insulator, in particular a hollow tubular and/or circular cylindrical insulator, in particular made of silicone, ceramic and/or composite materials with in particular ribs on the outer circumference, can be attached to the flange in a mechanically stable manner, in particular with a central axis of the insulator congruent with a longitudinal axis of the at least one electrical conductor.
• a flange enables a mechanically stable, permanently strong and in particular gas-tight attachment of an insulator to the encapsulating housing.
• a gas-tight housing for the high-voltage device with an encapsulating housing and insulators is thus possible, which at least partially has electrically shielded conductors in the housing.
• the conductors, electrodes, and / or devices such.
• Switching units, in particular arranged in the I solator and/or encapsulation housing are thereby z.
• At least one electrode at ground potential can be included in the leadthrough, in particular spatially included.
• further shielding of electrical fields in the area of the openings in the encapsulating housing is provided, in particular good shielding of the openings from the electrical or current-carrying conductor.
• the combination of an electrode at ground potential with an insulating layer on the electrical conductor results in high dielectric strength in the area of the feedthroughs and/or in the area of the openings in the encapsulating housing, with the advantages described above.
• the combination increases the dielectric strength, particularly in the area of the feedthrough, in addition to using only one or more insulating layers.
• the arrangement of the at least one electrode at ground potential around the electrical conductor, spaced apart from the electrical conductor, which has at least one Is provided with an insulating layer allows a grounded arrangement or Attachment of the electrode to earth potential on the encapsulation housing or on the flange of the encapsulation housing around the openings, with a high shielding effect.
• the at least one electrode at ground potential can be made of a metal, in particular copper, aluminum and/or steel. consist, and / or made of a metallic alloy. Metals provide good electrical shielding effects, are inexpensive and easy to produce or mold in any form. easily editable .
• the I solator can be congruent with a central axis or identical to a central axis of at least one electrode at ground potential and / or the longitudinal axis of at least one current-carrying or. be arranged electrical conductor.
• At least one switching unit of a high-voltage power switch can be included, in particular arranged in the encapsulating housing and/or connected via the at least one electrical conductor to power consumers, power generators and/or lines of a power grid.
• Switching units of high-voltage circuit breakers are installed in encapsulating housings of the type described above, with at least one bushing for at least one current-carrying or Electrical conductors, with which the advantages described above are associated as high-voltage devices in particular for the high-voltage circuit breakers.
• the at least one electrical conductor can consist of a metal, in particular copper, aluminum and/or steel, and/or a metallic alloy.
• the at least one electrical conductor can have the shape of a, in particular, circular-cylindrical bar and/or a rod.
• metals such as B. Copper, aluminum, and/or steel are good electrical conductors and have low electrical losses even at high currents, especially in the range of up to a few hundred amperes, in a high-voltage device.
• the rounded shape of electrical conductors in particular in the form of circular-cylindrical beams and/or rods, in particular with a diameter in the range of centimeters, prevents excessive voltage increases at edges and results in electrical field distributions around the electrical conductor when current is flowing, which can cause electrical flashovers in the area of the Minimize or impede .
• the high-voltage device in particular the encapsulating housing and/or the bushing, can be filled with clean air.
• Clean Air is cost-effective and environmentally friendly, especially climate-neutral.
• a lower dielectric strength of Clean Air compared to conventional insulating gases such as e .g . B. SF 6 can through the use of an insulating layer on the electrical conductor, particularly in the area of openings in the encapsulating housing with current-carrying or electrical conductors, are balanced.
• a method according to the invention for increasing the dielectric strength in a high-voltage device comprises that at least one electrical conductor is coated with an insulating layer, in particular in a region of a passage for the at least one electrical conductor leading into an encapsulating housing of the high-voltage device and/or leading out of the encapsulating housing.
• Figure 1 schematically coated an electrical conductor 4 with an insulating layer 5, and the
• Figure 2 shows a schematic sectional view of a section of a high-voltage device 1 according to the invention, with an opening in an encapsulating housing 2, and with a bushing 3 for a current-carrying conductor 4 through the opening, the electrical conductor 4 being coated with an insulating layer 5.
• FIG. 1 shows an electrical conductor 4 which is used in a high-voltage device according to the invention as a current-carrying conductor for the electrical connection of power consumers, power generators and/or power lines in a power grid.
• the electrical conductor 4 is in the form of a circular cylindrical rod or. a circle cy- Linderf örmigen tube formed, with a lateral surface which is partially coated with an insulating layer 5.
• the electrical conductor 4 is z. B. from and / or includes copper, aluminum and / or steel. The diameter is z. B. in the range of 1 to 10 centimeters and the length is z. B. in the range of 1 to 10 meters.
• the insulating layer 5 is made of and / or includes z. B. silicone, Teflon, PTFE and / or PCTFE.
• the layer thickness is z. B. in the range of a few millimeters to centimeters, in particular 1 centimeter.
• the electrical conductor 4 is only partially coated with the insulating layer 5, e.g. B. only half its length.
• FIG. 2 shows a schematic sectional view of a section of a high-voltage device 1 according to the invention, with an opening in an encapsulating housing 2 of the high-voltage device 1.
• the opening comprises a flange 9 which is ring-shaped or rim-shaped.
• In the flange 9 are holes for fasteners such. B. screws.
• a hollow tubular insulator 10 is arranged standing perpendicularly on the flange 9 and is fastened to the flange 9 in a mechanically stable manner via the fastening means, in particular screws.
• the encapsulating housing 2 with flange 9 is z. B. made of a metal, in particular aluminum.
• the insulator 10 is z. B. ceramic, silicone and / or composite material f en.
• flange - shaped ribs are formed to lengthen leakage current paths .
• the hollow tubular insulator 10 with a circular cross section, has a longitudinal axis 6 which is perpendicular to the opening plane of the circular opening and intersects or pierces the opening in the encapsulating housing 2 at the center of the circle.
• a switching unit of a high-voltage circuit breaker comprised by the high-voltage device 1 according to the invention, arranged and electrically connected via conductor 4 to power consumers, power generators and / or power lines of a power grid outside of the encapsulating housing 2.
• An electrical conductor 4 which is a current-carrying conductor 4 when the high-voltage device 1 is in operation or when the switching unit is in the closed state, is particularly rod-shaped or bar-shaped, as shown in detail in Figure 1, with a longitudinal axis that is conclusive or identical to the longitudinal axis 6 of the insulator.
• the conductor 4 When current flows through the electrical conductor 4, there is an electrical and magnetic field around the conductor 4.
• the conductor 4 is at high voltage potential, in particular up to 1200 kV, and the encapsulating housing 2 is grounded, ie at ground potential.
• the potential difference between the grounded encapsulating housing 2 and the current-carrying conductor 4 can lead to flashovers and/or short circuits.
• the opening in the encapsulating housing 2 has a sufficient radius, which ensures a minimum distance between the conductor 4 and the encapsulating housing 4 that is large enough to prevent voltage flashovers.
• the minimum distance required depends on the insulating gas with which the encapsulating housing 4 and the insulator 10 are filled, e.g. B.
• the electrode 7 is made of a metal, in particular aluminum, copper and/or steel, in the form of a hollow cylinder or hollow tube, with a circular cross section.
• the hollow tubular electrode 7, with a circular cross section has a longitudinal or central axis 6 which is perpendicular to the opening plane of the circular opening and intersects or pierces the opening in the encapsulating housing 2 at the center of the circle.
• the longitudinal or central axis of the electrode 7 at ground potential is conclusive or identical to the longitudinal axis 6 of the insulator 10.
• the electrode 7 is secured with fastening means, e.g. B. screws, on the flange 9 of the encapsulating housing 2 mechanically stable and electrically conductive, and protrudes into the insulator 10 or in the cavity inside.
• the electrode 7 changes the electric field between the encapsulating housing 2 and the current-carrying conductor 4 in such a way that excess voltage at the opening of the encapsulating housing 2 or the flange 9 is shielded by the electrode 7 or is shifted into the interior of the insulator 10 .
• an insulating layer 5 on the electric conductor 4 changes the electric field along the electric conductor 4 in such a way that it is unified and further shifted into the interior of the insulator 10 and into the encapsulating housing 2 .
• the probability of free strong electrons initiating an electrical breakdown between the electrical conductor 4 and the encapsulating housing 2 is inhibited.
• Local field increases due to surface roughness on the surface of the electrical conductor 4 are reduced or prevented.
• High-voltage devices 1 include high-voltage circuit breakers, separators, transformers, arresters, instrument transformers and/or bushings.
• High-voltage devices 1, in particular circuit breakers are z.
• the basic principle, with an insulating layer on a conductor in a passage of the conductor through openings at ground potential, can also be used in outdoor circuit breakers or outdoor high-voltage devices.
• the invention can be used in dead-tank systems, ie arranged with a switching unit in a grounded housing.
• the electrical conductor 4 is z. B. circular-cylindrical. Other forms, e.g. B. with elliptical cross-section and / or designed as a truncated cone are also possible.
• the encapsulating housing 2 of the high-voltage device 1 is z. B. kettle-shaped, and sealed gas-tight on the insulators 10. Boilers are e.g. B. spherical or cylindrical, other shapes are also possible. Connections between elements of the high-voltage device are made z. B. mechanically stable fasteners, especially screws, and at least one flange.
• connection techniques in particular adhesive, welded and/or soldered connections, can also be used.
• seals for the gas-tight connection of elements in particular copper seals, is possible.
• the insulating layer 5 on the electrical conductor 4 is z. B. formed as a layer or as a layer stack of multiple layers.
• the layers can have different permittivities, in particular decreasing permittivity from layer to layer, e.g. B. with the highest permittivity of the layer directly in connection with the at least one electrical conductor 4.
• z. B. the permittivity of the inner layer is highest
• each additional layer is formed with a lower or with decreasing permittivity, but with a permittivity always greater than the permittivity of gas, ie greater than 1, a more pronounced equalization of the electric field in the can be achieved compared to just one layer in order to further relieve the dielectric load on the critical areas.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Gas-Insulated Switchgears (AREA)
• Insulating Bodies (AREA)
• Insulators (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=78032390

Family Applications (1)

Country Status (6)

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Family Cites Families (10)

• 2020
  • 2020-09-30 DE DE102020212384.5A patent/DE102020212384A1/de active Pending
• 2021
  • 2021-09-13 JP JP2023519119A patent/JP2023543237A/ja active Pending
  • 2021-09-13 US US18/029,446 patent/US20230377778A1/en active Pending
  • 2021-09-13 EP EP21783403.5A patent/EP4197073A1/de active Pending
  • 2021-09-13 WO PCT/EP2021/075060 patent/WO2022069197A1/de unknown
  • 2021-09-13 CN CN202180067414.4A patent/CN116438612A/zh active Pending

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