Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F27/00—Details of transformers or inductances, in general
  • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
  • H01F27/343—Preventing or reducing surge voltages; oscillations
  • H01F27/345—Preventing or reducing surge voltages; oscillations using auxiliary conductors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F27/00—Details of transformers or inductances, in general
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/2871—Pancake coils

Definitions

• the surge voltage resistance of transformer windings for nominal voltages from 220 kV is usually achieved in that the winding is made up exclusively of coils wound into one another or in that the surge voltage is reduced in the input region of the winding with graded external capacitances to such an extent that the rest of the winding is in a normal double-coil circuit, for example from wire ladders, is executable.
• the invention relates to a capacitively controlled high-voltage winding consisting of disk coils for transformers with large nominal powers with a main conductor designed as a stranded conductor and carrying the load current and with a control conductor spatially parallel to it.
• a capacitively controlled high-voltage winding is known from DE-OS 24 18 230.
• the high-voltage winding shown there has a plurality of disc coils arranged axially one above the other, which are continuously wound from a main conductor designed as a stranded conductor. Spatially parallel to the main conductor, a control conductor is continuously wound over a winding section of at least four disk coils.
• the control conductor is separated in the middle of this winding section and its beginning and end outside the winding are galvanically connected to each other. This connection made by soldering is practically unproblematic because the control conductor can be soldered without difficulty as a solid conductor.
• a further winding arrangement is known from German patent specification 1 297 217, which contains control conductors for the capacitive control of a solid main conductor.
• This winding is composed of continuously wound double coils and the control conductors are of different lengths in order to achieve graded longitudinal capacities in the double coils.
• the main conductor of the double coils is formed from two solid conductors which are electrically connected in parallel and run spatially in parallel and are thereby electrically insulated from one another, between which the control conductor designed as a metal foil is wrapped.
• the longitudinal capacitance and the surge voltage distribution are both in the winding design according to the German design specification 12 97 217 and in accordance with the DT 24 18 230 AI
• Winding also depends on the winding density. However, the winding density fluctuates undesirably with the manufacturing quality achieved in each case.
• a twisted pair for coils for transformers which consists of several flat subconductors which are guided in parallel and insulated from one another.
• the positions of the partial conductors in the cross section of the wire conductor are cyclically interchanged by cranking, so that each partial conductor cyclically occupies every possible position in the cross section of the wire conductor over the length of the wire conductor.
• a step winding for transformers which has several partial windings electrically connected in series.
• Each of the partial windings is formed from a single conductor, to which a respective one
• Control conductor is arranged spatially in parallel.
• the control conductors and the individual conductors are electrically isolated from each other.
• a transformer with a winding from a main conductor carrying the load current is known, which usually consists of a material with high conductivity.
• An additional conductor made of a resistive material is arranged spatially parallel to the main conductor over at least part of its length. The additional conductor serves to dampen vibrations.
• a high current conductor for the connecting lines of windings is known, in addition to which a shield conductor is spatially parallel.
• the shield conductor is galvanically connected to the current-carrying conductor via so-called “potential connections” in such a way that the total current in the shield conductor is zero.
• the shield conductor serves to shield the magnetic field from the current carried in the high-current conductor, so that structural parts exposed to its magnetic field are not impermissibly thermally stressed by eddy currents induced therein.
• the invention has for its object to provide a control conductor arrangement for high-voltage windings of the first-mentioned type, which has a larger longitudinal capacitance and also a comparatively simple and safe manufacture and high operational reliability of the high-voltage winding during use in a transformer.
• Longitudinal capacitance is understood to mean the electrical capacitance, based on a unit of length, between the winding-forming main conductors and the control conductor.
• Control conductor is arranged spatially within the main conductor, and that the control conductor is galvanically separated from the main conductor.
• control conductor lies within the main conductor designed as a twisted conductor, it is spatially very close to all the partial conductors from which a twisted conductor is usually formed, so that there is a large longitudinal capacitance.
• longitudinal capacitance of this high-voltage winding is independent of any axial cooling channels that may be present.
• a high-voltage winding can be produced particularly easily with such a main conductor because the main conductor and the control conductor can be wound at the same time.
• there is a high level of operational reliability in that the control conductor lies within the main conductor, that is to say it is shielded from the outside by the main conductor.
• the maximum voltage stress on the control conductor between two axially adjacent coils is due to this shielding only twice the voltage across a disc coil.
• control conductor is arranged spatially between two stacks of individual conductors lying flat on top of one another and forming the main conductor and stands upright between the two stacks of the individual conductors of the main conductor.
• the control conductor arranged in this way rests on the corresponding side faces of the stack. These side surfaces are very flat compared to the outer surface of a twisted pair conductor, so that there is a very small distance between the side surfaces and the control conductor and thus a very large longitudinal capacitance.
• control conductor forms a rectangle in cross section with a ratio of length to width of approximately 15: 1 and the overall cross section of the main conductor including the control conductor is approximately square.
• the control conductor is preferably formed from a plurality of individual conductors lying spatially parallel and electrically insulated from one another. This results in low eddy current losses in the control conductor.
• control conductor extends over a part of the disk coil and that a filling of insulating material is provided in the main conductor in the remaining part of the disk coil.
• the number of windings provided with a control conductor within a disk coil preferably decreases with increasing distance between the disk coil and the connection of the high-voltage winding.
• the longitudinal capacitance decreases from the connection into the high-voltage winding, and a distribution of a voltage surge occurring at the connection to a large number of turns in the high-voltage winding is achieved.
• An intermediate layer is preferably arranged between the two stacks of sub-conductors forming the main conductor in disc coils without control conductors.
• a connecting lug of the control conductor is led out of the outermost turn of a disk coil having a control conductor, and the connecting lugs of adjacent disk coils, the radially inner main conductor turns of which are connected by a coil connection, are galvanically coupled to one another via a control conductor connection.
• High-voltage windings designed in accordance with the invention are very advantageous because their longitudinal capacitance is significantly larger than in all known designs mentioned above due to the spatially extremely close coupling of the control conductor to the main conductor.
• the manufacturing effort required compared to the known solutions is rather less than higher.
• the high-voltage winding is held together after its completion by a clamping device which exerts an axial clamping force on the winding.
• FIG. 1 shows a high-voltage winding in section
• FIG. 2 shows a detail at A in FIG. 1 on a larger scale
• FIG. 3 shows a cross section through a main conductor with an integrated control conductor
• FIG. 4 shows a cross section through a main conductor with a filling
• 5 shows a cross section through a main conductor with a
• FIG 6 shows a cross section through a main conductor with a control conductor formed with several individual conductors.
• a high-voltage winding 1 of a transformer with a high rated power, for example more than 200 MWA and a rated voltage of 220 kV or more, which is directed along an axis 16, has connections 2 and 3, the connection 2 forming the high-voltage connection (see FIG. 1).
• the high-voltage winding 1 is composed of disk coils 4A to 4L (see FIG. 2).
• the disc coils 4A to 4L are wound from a main conductor 5 with a preferably approximately square cross section, the main conductor 5 in the disc coils 4A, 4C, 4E, 4G, 41 and 4K in each case from the outside inwards and in the disc coils 4B, 4D, 4F, 4H, 4J and 4L is wound inside out.
• the disk coils 4A to 4L are electrically connected in series via coil connections 6 located within the high-voltage winding 1 and via coil connections 7 located on the outer circumference of the high-voltage winding 1 (see FIG. 2).
• the disk coils 4A to 4L are electrically connected in series via coil connections 6 located within the high-voltage winding 1 and via coil connections 7 located on the outer circumference of the high-voltage winding 1 (see FIG. 2).
• the disk coils 4A to 4L are electrically connected in series via coil connections 6 located
• Disc coils 4A to 4L can also be in pairs (4a, 4B); (4C, 4D); (4E, 4F); (4G, 4H); (41, 4J) and (4K, 4L) are each combined in a double coil, and each double sink can be wound from a main conductor.
• the main conductor 5 (see FIGS. 3 to 5) consists of two stacks 16 and 17 lying parallel to one another and of partial conductors 8 lying against one another with their broad sides, which are insulated from one another but nevertheless electrically connected in parallel.
• entanglements 9, of which only one is shown alternate one of the partial conductors 8 from a stack 16 to guided another stack 17 and one of the partial conductors 8 from the other stack 17 to a stack 16 out.
• This exchange takes place cyclically along the main conductor 5, so that each partial conductor 8 occupies every possible partial conductor position per length section of the main conductor 5.
• This forms a so-called twisted pair which is also called Roebel rod in power generator construction.
• control conductor 10 has an approximately rectangular cross section, the rectangle being a length
• the control conductor 10 can be designed as an insulated solid conductor, in particular as a flat conductor, or similar to the main conductor 5 from a plurality of individual conductors 15 lying radially one above the other and insulated from one another (see FIG. 6).
• the filling 11 is made of insulating material, has the same cross section as the control conductor 10 and also has the same sheathing as this.
• the intermediate layer 12 has a cross section like the control conductor 10 including insulation.
• control conductor 10 the filling 11 with sheathing or the intermediate layer 12 stand upright between the two stacks of the individual conductors 8. This creates a close spatial arrangement of the individual conductors 8, in particular with respect to the control conductor 10.
• the parallel and spatially closely spaced individual conductors 8 on the one hand and the control conductor 10 on the other hand form a capacitor with a relatively high capacitance due to their small spatial distance from one another.
• one control conductor 10A or 10B in the first and second disk coil 4A or 4B extends over all five turns, one control conductor IOC or 10D in the third and fourth disk coil 4C or 4D over each three turns, one control wire 10E or 10F in the fifth and sixth disk coil 4E or 4F each with 2 turns and one control wire 10G to 10J in the seventh to tenth disk coil 4G to 4J each with one turn.
• the disc coils 4K and 4L which then follow in the high-voltage winding 1 are free of control conductors and are only padded with the intermediate layer 12.
• the fillings 11C to 11J are provided in the control conductor-free windings of the disk coils 4A to 4J instead of a control conductor.
• control conductors 10A-10J are each led out of their respective disk coils 4A-4J via a connecting lug 13A-13J and are electrically contactable.
• connection lugs 13A to 13J of the disk coils 4A to 4J which are directly connected to one another via a coil connection 6, that is to say the disk coils (4A, 4B); 4C, 4D); (4E, 4F); (4G, 4H) and (41, 4J) are electrically connected to each other outside the high-voltage winding 1 by a control conductor connection 14A to 14E.
• a control conductor connection 14A to 14E This means that the control conductors 10A and 10B or IOC and 10D or 10E and 10F or 10G and 10H or 101 and 10J are electrically connected in series.
• the longitudinal capacitance of the disk coils 4A and 4B is highest and the respective longitudinal capacitance of the disk coils 4B to 4J is the lowest. In other words: going from the connection 2 along the main conductor 5 into the high-voltage winding 1, the longitudinal capacitance drops. As a result, in particular high-frequency voltage surges with which connection 2 is acted upon are thus transmitted to the
• High-voltage winding 1 initiated that the voltage drop is distributed over many turns. In the ideal case, depending on the frequency of the voltage surge, an approximately uniform distribution of an incident voltage surge on the high-voltage winding 1 is forced by the decreasing longitudinal capacitance.
• the disk coils 4A-4L which are not shown in any more detail and which lie in the high-voltage winding 1 below section A according to FIG. 1, can be designed with a main conductor designed as a twisted conductor without a control conductor and without filling or intermediate layer.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Coils Of Transformers For General Uses (AREA)
• Coils Or Transformers For Communication (AREA)
• Thermistors And Varistors (AREA)
• Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
• Dc-Dc Converters (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

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Family Cites Families (9)

• 1999
  • 1999-06-10 DE DE19926540A patent/DE19926540C1/de not_active Expired - Fee Related
• 2000
  • 2000-06-09 BR BRPI0011458-8A patent/BR0011458B1/pt not_active IP Right Cessation
  • 2000-06-09 WO PCT/DE2000/001920 patent/WO2000077800A1/fr active IP Right Grant
  • 2000-06-09 CN CNB008086532A patent/CN1165057C/zh not_active Expired - Fee Related
  • 2000-06-09 DE DE50013938T patent/DE50013938D1/de not_active Expired - Lifetime
  • 2000-06-09 EP EP00949084A patent/EP1183696B1/fr not_active Expired - Lifetime
  • 2000-06-09 AT AT00949084T patent/ATE350756T1/de active
  • 2000-06-09 PT PT00949084T patent/PT1183696E/pt unknown

Non-Patent Citations (1)

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