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
  • H02B13/0356—Mounting of monitoring devices, e.g. current transformers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
  • H01F38/20—Instruments transformers
  • H01F38/22—Instruments transformers for single phase ac
  • H01F38/28—Current transformers
  • H01F38/30—Constructions
• • 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
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
  • H01F38/20—Instruments transformers
  • H01F38/22—Instruments transformers for single phase ac
  • H01F38/28—Current transformers
  • H01F38/30—Constructions
  • H01F2038/305—Constructions with toroidal magnetic core
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
  • H01F38/20—Instruments transformers
  • H01F38/38—Instruments transformers for polyphase ac

Definitions

• aspects of the invention relate to the field of electrical current sensors, in particular the current transformer for switchgear for high or medium voltage.
• aspects relate to embodiments of a gas-insulated power conversion unit.
• current transformers are generally used. These consist for example of a ferrite core, on which a copper winding is wound. The annular power converter core is slid over one end of the nominal conductor for mounting so that the conductor passes through the interior of the ring. If a load current flows through the conductor, a voltage is induced in the winding of the current transformer core, which voltage is tapped off via a resistor and serves as a measure of the current through the nominal conductor.
• a nominal conductor is a primary conductor used to transmit the rated power during the operation of the switchgear.
• the or the current transformer cores can be arranged both inside and outside the gas encapsulation of the conductor, so the housing. Since the outer diameter of the current transformer cores clearly exceeds the outer diameter of the encapsulation of the nominal conductors in such a case, the minimum distance of the encapsulated nominal conductors, given the outer diameters of the current transformer cores and a concentric one, is arranged next to each other, parallel to one another, with gas-encapsulated nominal conductors each having a current transformer core Arrangement of the current transformer cores to the nominal conductors from each other ultimately determined by the dimensions of the current transformer.
• the dimensions of the current transformer cores are in turn determined by a metrologically required cross-section and manufacturing requirements.
• the current transformer cores therefore essentially determine the minimum achievable distance between the nominal conductors.
• Special designs of current transformer cores, for example, with a reduced compared to a standard design outside diameter are usually very costly and therefore, for example, to achieve an inexpensive switching field economically uninteresting and disadvantageous.
• the medium or high voltage switchgear has at least two current transformer units.
• Each of these current transformer units has the following elements:
• a current transformer core which is formed with respect to its central axis substantially rotationally symmetric and annular, wherein the current transformer core has a respect to its central axis radially inwardly directed inner circumferential surface and an outer diameter;
• the longitudinal axes of the nominal conductors can be arranged at given external diameters of the current transformer cores and with a concentric arrangement of the current transformer cores to the nominal conductors at a reference distance from one another.
• a minimum achievable distance is called the reference distance Longitudinal axes of two adjacent nominal conductor understood. This reference distance is justified as follows:
• switchgear is also understood in the following to be a component of a medium or high-voltage switchgear, such as a so-called switchgear module, which is used for the measurement of the electrical current flowing through the respective nominal conductors.
• the switchgear is further characterized by the fact that at least one of the two Stromwandlerkerne is eccentrically fixable to its nominal conductor due to the holding means that an achievable actual distance between the longitudinal axes of the nominal conductor at given outer diameters of the current transformer cores in the above case constellations ac smaller than the reference distance.
• This basic embodiment of a medium or high voltage switchgear allows the plant manufacturer and his customer the greatest possible design freedom of his switchgear, as can be both air-insulated switchgear, for example, outdoor facilities, as well as single-phase or multi-phase encapsulated embodiments gas insulated switchgear (GIS) realize.
• GIS gas insulated switchgear
• both switchgear can be realized, in which the Stromwandlerkerne are arranged outside the actual gas space, as well as embodiments in which the Stromwandlerkerne are arranged within the actual gas space.
• current transformer core is not to be understood in the following description and the claims as narrowing down to an iron core of a current transformer briefly mentioned in the following:
• the term “current transformer core” rather refers to the actual body or an envelope of the current sensor understood measuring device understood.
• current transformer core is therefore not limited to current transformers, which consist of a ferrite core with copper winding wound thereon, but also includes so-called Rogowski coils, in which the copper coil comprises a toroidal cavity because, with an eccentric arrangement of its central axis to the longitudinal axis of the nominal conductor, the measurement quality is not impaired.
• the nominal conductor of the current transformer units of each phase is arranged in each case gas-insulated within a metal-encapsulated enclosure.
• the encapsulation is arranged between the respective nominal conductor and the inner circumferential surface of the current transformer core assigned to it.
• the holding means of the current transformer units for example, each designed as at least one annular element which comprises a extending in the direction of the longitudinal axis of the nominal conductor holding means axis, and whose inner diameter substantially corresponds to an outer diameter of the associated encapsulation.
• the annular element has a holding means axis and at least one mounting geometry, which is arranged on a centerline to the holding means axis of the element eccentrically arranged.
• the current transformer core can be fastened to the attachment geometry of the holding means in such a way that it can be fastened concentrically to this circle on the holding means.
• the attachment geometry includes at least one of the elements of the list consisting of: a bore, a thread, a threaded sleeve, and a stud. If, for example, a particularly versatile and yet space-saving retaining means is required, the annular element may have a plurality of segments or consist of several, for example, chain-like members.
• the holding means allows to achieve an offset of the central axis of the current transformer to the longitudinal axis of the nominal conductor of more than about 5% of the nominal conductor diameter.
• an offset of between 5% and 50% of the nominal conductor diameter can be achieved.
• switchgear can be realized, the current transformer cores of the three power converter units are arranged side by side in a plane, and in which switchgear a height should be particularly compact.
• the longitudinal axes of the nominal conductors are arranged parallel to one another in a planar plane, and if each nominal conductor is arranged gas-insulated within a metal-encapsulated enclosure extending concentrically with the respective nominal conductor.
• the metal-encapsulated encapsulations are arranged at a regular distance along a straight line.
• Particularly small actual distances between at least two adjacent nominal conductors can be achieved for example by the fact that the current transformer cores are arranged by means of the holding means to the encapsulations of the two outer nominal conductor each eccentric to the longitudinal axes of the nominal conductor, that a largest gap between encapsulation and the inner circumferential surface of the current transformer core assigned to the respective encapsulation is located on a side of the encapsulation of the two outer nominal conductors facing away from the two other nominal conductors.
• the actual distance between two adjacent nominal conductors can be reduced alternatively or in combination additionally or, in such a switchgear with three current transformer units, at least two of the three current transformer cores in the direction of the longitudinal axis of the nominal conductor against each other offset can be arranged so that the current transformer cores seen in the direction of the longitudinal axis of their nominal conductor, overlap.
• each nominal conductor is arranged in a gas-insulated manner within a metal-encapsulated enclosure extending concentrically with the respective nominal conductor, wherein the metal-encapsulated enclosures are arranged at a regular distance along a straight line.
• the current transformer cores by means of the holding means on the encapsulations of the two outer nominal conductors each such eccentric to the longitudinal axes of the nominal conductor can be arranged that a largest gap between the encapsulation and the inner circumferential surface of the respective encapsulation associated Stromwandlerkerns on one of the two other nominal conductors facing away from the encapsulation of the two outer nominal conductor is located.
• the gap in the direction of the longitudinal axes of the nominal conductors has a crescent-shaped cross section, the largest gap being at an axis of symmetry of the crescent-shaped cross section.
• the present invention is advantageous not only in switchgear, where the mutually parallel longitudinal axes of the nominal conductors are in a common plane, but also in the so-called triangular arrangement.
• the longitudinal axes of the nominal conductors extend parallel to one another and penetrate a penetration plane extending at right angles to the longitudinal axes of the nominal conductors in three points, the three points in the penetration plane forming corner points of an isosceles triangle.
• the nominal conductors are different electrical phases in a common gas space by an insulating gas with each other and to a common housing comprises, which forms the enclosure and delimits the gas space.
• a common housing comprises, which forms the enclosure and delimits the gas space.
• three mutually parallel arranged nominal conductors which are arranged in a common gas-encapsulated housing, and three disposed within the housing current transformer units.
• D e of the three current transformer units at least one is a current transformer unit according to the basic embodiment mentioned at the beginning.
• the holding means makes it possible to achieve an offset of the central axis of the current transformer to the longitudinal axis of the nominal conductor of more than about 5% of the nominal conductor diameter.
• an offset between 5% and 50% of the nominal conductor diameter can be achieved.
• the medium or high voltage switchgear includes three power converter units whose power converter cores are arranged side by side in a common plane.
• the present invention is advantageous because it can reduce the reference distances between two adjacent nominal conductor sometimes as follows. This can be achieved, for example, by the longitudinal axes of the nominal conductors extending parallel to one another and penetrating a penetration plane extending at right angles to the longitudinal axes of the nominal conductors in three points, the three points forming an isosceles triangle in the penetration plane.
• Fig. 1 shows a side view / longitudinal sectional view of a switchgear with three
• Fig. 2 shows a cross-sectional view of the embodiment of Fig. 1;
• Fig. 3 shows a plan view of a holding means in the direction of the holding means axis
• FIG. 3a shows a side view of the holding means according to FIG. 3;
• Fig. 4 shows a side view / longitudinal sectional view of a switchgear with three
• FIG. 5 shows a cross-sectional view of a switchgear with three current transformer modules according to a third embodiment
• Fig. 6a is a cross-sectional view of a starting position for further embodiments of switchgear
• Fig. 6b is a cross-sectional view of a fourth embodiment of a switchgear
• Fig. 6c is a cross-sectional view of a fifth embodiment of a switchgear.
• Fig. 7 representation of the dependence of the offset a and the radius r of the current transformer in cross-sectional view.
• Fig. 1 shows in conjunction with Fig, 6a and Fig. 6b, an embodiment of the invention, which can be combined with other embodiments mentioned or shown here, and a gas-insulated high or medium voltage switchgear with three power converter units 1, 2, 3rd concerns.
• three current transformer cores 10, 20, 30 of the three current transformer units 1, 2, 3 by means of a respective holding means 50, 60, 70 attached to the enclosures 140, 150, 160 each of a nominal conductor 90, 100, 100 attached or fixed.
• the metal-encapsulated housings or encapsulations 140, 150, 160 are each arranged concentrically to the respective nominal conductors 90, 100, 100 and each have an encapsulation diameter 141, 151, 161.
• the holding means 50, 60, 70 serve to fix the current transformer core in a relative position to the nominal conductor 90, 100, 110, so that the central axis of the current transformer core 10, 20, 30 parallel to the longitudinal axis of the nominal conductor 90, 100, 1 10 extends.
• Each current transformer core defined by its annular cylindrical shape a central axis 15, 25, 35 and is substantially rotationally symmetric and annularly shaped, wherein the current transformer core 10, 20, 30 with respect to its central axis 15, 25, 35 radially inwardly (that is radially to directed inside) directed inner circumferential surface 11, 21, 31 and an outer diameter 12, 22, 32 has.
• Each nominal conductor 90, 100, 100 for transmitting a medium or high voltage in turn defines by its cylindrical shape a longitudinal axis 92, 102, 112 and has a nominal conductor diameter 91, 101, 111.
• Each holding means 50, 60, 70 has its own holding means axis 51, 61, 71.
• the holding means are designed and mounted in such a way that a parallel-eccentric arrangement of the current transformer cores with respect to the nominal conductors 90, 100, 100 or their encapsulations 140, 150, 160 results.
• the three identical current transformer cores 10, 20, 30 are arranged in a plane 170, and touch this plane 170 frontally.
• an offset of the longitudinal axes of the nominal conductors 90, 100, 100 can be brought about an actual distance 82 between two adjacent nominal conductors 90, 100, 100, which is smaller than a theoretical reference distance 80 given external diameters 12, 22, 32 the current transformer cores, in which the outside of the outer radial outside touch outside diameter on its outer diameters (see also the top view of FIG. 7).
• Fig. 2 shows a cross-sectional view of the embodiment according to the embodiment of the switchgear shown in Fig. 1.
• the outer diameter 12, 22, 32 of the current transformer cores 10, 20, 30 are shown enlarged with their central axes 15, 25, and 35 in relation to the sizes of the nominal conductors 90, 100, 110 and their encapsulations for illustrative purposes.
• the dimension a defines the offset between the longitudinal axis of the nominal conductor and the center axis of the current transformer core in all three current transformer units 1, 2, 3. The larger a, the closer the nominal conductors can be structurally brought together, provided that the dimensions of the encapsulations 140, 150, 160 and the dimensions of the current transformer cores are each the same size.
• the eccentricity a is typically from 5 mm to 40 mm, for example 12.5 mm, 16 mm, or 22 mm.
• the axes of the current transformer cores and the longitudinal axes of the nominal conductors or the encapsulations are typically parallel.
• the design of the eccentricity a is dependent on the dimensions of the plant and on the degree of freedom for a collapse in the sense of pushing the nominal conductors against one another, which is to be achieved by the eccentric arrangement.
• g is the amount of length by which each of the two outer Stromwandlerkerne can be moved closer to the inner or mounted.
• a schematic representation of the gain g between two adjacent current transformer cores 10, 20 as a function of a and r is shown by way of example in FIG. 7.
• the top figure shows the two transducers in the conventional initial state, the middle figure the two transducers after eccentric mounting of the left core by a down (an intermediate state shown for illustrative purposes only), and the bottom figure the two cores after passing through the the offset a allowed gain g were mounted closer to each other.
• the gain g is relatively low in such eccentric mounting only the middle of three power converter cores.
• transducer diameter of twice the radius (2r) of 300 mm results in an eccentricity a of 20 mm according to the above formula, a gain g of 2.7 mm, to which the outer cores closer can be mounted to the middle.
• a significantly higher profit is additionally due to the eccentric mounting of the two outer current transformer cores.
• the eccentricity with appropriate installation fully profit as an advantage, an eccentric mounting of the outer core by 20 mm so allows only a contraction by 20 mm of the outer with the middle Stromwandlerkerns.
• the mentioned 2.7 mm add up to each.
• the current transformer cores are each arranged so eccentrically on the encapsulations (140, 160) of the two outer nominal conductors (90, 110) by means of the holding means (50, 70) for maximum gain, in that the greatest distance between encapsulation (140, 160) of the nominal conductor and the inside of the current transformer core (10, 30) is typically located in a hemisphere of the encapsulation facing away from the other two nominal conductors. Preferably, these largest distances are located substantially on a common line, with the maximum profit is achieved.
• the inventive method or the proposed means are applicable to current transformer cores of all sizes, after appropriate adjustment of about the size of the holding elements 50, 60, 70.
• the current transformer cores 10, 20, 30 are on the enclosures 140, 150, 160 secured in one embodiment with holding means 50, 60, 70, which comprise annular elements.
• Such an element in the form of a disk is shown schematically in FIG.
• the disk typically has two or more annular segment-shaped segments 120, 130.
• Four fastening geometries 80 in the form of a through hole serve for fastening the current transformer core with screw through the segments 120, 130 hin trimckbaren.
• the attachment geometries 80 are arranged on a circle 83, the center of the circle is arranged offset by the eccentricity a relative to the geometric center of the annular disc in the form of the holding means axis 51.
• Segments 120, 130 are typically made of plastic or other non-magnetic materials, such as aluminum, its alloys, or non-magnetic steels.
• two support means 50, 60, 70 are provided per current transformer core, one on each side (as viewed with respect to the direction of the nominal conductor).
• the segments 120, 130 of the disc are positioned on the enclosure, wherein the inner diameter of the disc ring or the sub-segments 120, 130th typically corresponds approximately to the outer diameter of the encapsulation 140, 150, 160.
• the segments can then be fastened to one another or to the encapsulation using measures which belong to the prior art.
• the retaining element 50, 60, 70 fastened in this way serves as a fastening element for the current transformer core, with screws being inserted through the bores 80 and screwed into threads of the current transformer core. In this way, a stable, to the length a eccentric mounting position of the current transformer to the nominal conductor or its encapsulation can be achieved.
• FIG. 3 a shows a side view of the ring-shaped or disk-shaped holding element 50, 60, 70 from FIG. 3.
• the current transformer cores 10, 20, 30 are additionally arranged offset along the longitudinal axis of their respective nominal conductors 90, 100, 110 by at least the amount of their length, viewed in the direction of the nominal conductor, offset from each other.
• an even smaller distance of the nominal conductors from one another can be achieved (as viewed in the direction of the nominal conductor) an overlap of the outer lateral surfaces of the current transformer cores becomes possible, as shown in FIG , Fig. 5 shows another embodiment.
• three nominal conductors 90, 100, 110 arranged parallel to one another are arranged in a common gas-encapsulated housing 200.
• Each nominal conductor is enclosed in a longitudinal section radially by a current transformer core 10, 20, 30.
• the eccentric arrangement of the current transformer cores around the conductors makes smaller distances between the nominal conductors possible, with otherwise identical dimensions of the current transformer cores.
• This embodiment can also be combined with the example shown in FIG. Since in this example all three current transformers are located in the field of the three conductors, which typically represent different phases, additional measures must be taken to ensure reliable operation and measurement. This includes, for example, the attachment of metal sheets between the nominal conductors and the respective power transformer cores, wherein the sheets are at the potential of the common housing 200.
• the current transformer cores are each such eccentric to the longitudinal axes of the nominal conductor 90, 100, 1 10 arranged that a largest gap between encapsulation 140, 160 of the nominal conductor and the inner circumferential surface 1 1, 21, 31 of the associated Stromwandlerkerns 10, 30th is located in a hemisphere of the encapsulation facing away from the two other nominal conductors
• Fig. 6a shows the comparison between a conventional Stromwandler- arrangement (above) of an inventive arrangement for a three-phase switchgear with three current transformer units, the Stromwandlerkerne are identical, so that given the outer diameter 12, 22, 32 of the current transformer cores due to the eccentric Arrangement of the current transformer cores to the nominal conductors or to the encapsulations of the nominal conductors can be arranged closer to each other (see Fig. 6b), because the actual distance 82 is less than the reference distance 81.
• the three nominal conductors 90, 100, 110 having their enclosures 140, 150, 160 extending concentrically around them are arranged at regular intervals 81 on a common straight line 175.
• the straight line 175 extends mathematically normal to the longitudinal axes of the nominal conductors 90, 100, 110.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Transformers For Measuring Instruments (AREA)
• Gas-Insulated Switchgears (AREA)
• Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)

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Applications Claiming Priority (3)

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• 2011
  • 2011-06-22 RU RU2013102861/07A patent/RU2013102861A/ru not_active Application Discontinuation
  • 2011-06-22 KR KR1020127033553A patent/KR20130047695A/ko not_active Application Discontinuation
  • 2011-06-22 CN CN2011800310286A patent/CN103098154A/zh active Pending
  • 2011-06-22 EP EP11726793.0A patent/EP2586045A1/de not_active Withdrawn
  • 2011-06-22 WO PCT/EP2011/060387 patent/WO2011161129A1/de active Application Filing

Non-Patent Citations (1)

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