WO2005045853B1

WO2005045853B1 - System for transmission of electric power

Info

Publication number: WO2005045853B1
Application number: PCT/SE2004/001615
Authority: WO
Inventors: Rongsheng Liu; Stefan Johansson; Bjoern Holmgren; Stefan Valdemarsson; David Larsson; Kenneth Johansson; Tord Bengtsson; Gerhard Brosig; Lin Jiang; Dierk Bormann
Original assignee: Abb Research Ltd; Rongsheng Liu; Stefan Johansson; Bjoern Holmgren; Stefan Valdemarsson; David Larsson; Kenneth Johansson; Tord Bengtsson; Gerhard Brosig; Lin Jiang; Dierk Bormann
Priority date: 2003-11-07
Filing date: 2004-11-05
Publication date: 2005-09-29
Also published as: SE0302966L; WO2005045853A1; SE0302966D0; SE527008C2

Abstract

The invention concerns a high voltage transmission wire or cable for transmitting AC or DC power between two points. Preferably at least one point is connected to one or more power networks. The conductor of the wire or cable comprises a semiconducting outer layer (10) including distributed magnetic particles. Other embodiments include an insulation layer (12) including distributed magnetic material, micro-particles, ribbons tapes etc, and an insulation screen. The invention increases the distance over which power may be transmitted and/or eliminates the necessity for power compensation reactors partially or totally. This is achieved by increasing inductance and reducing AC capacitance leakage currents in AC lines and, when operated as a DC line, by reducing high frequency harmonics.

Claims

ARTICLE 19PCT/SE2004/001615 original claims 1-35 replaced by claims 1-35]

1. A power conductor for transmitting high voltage electric power between two points (A, B) at least one of which is connected to one or more power networks, characterised in that said conductor comprises a first outer layer (10) that comprises nano-partides and has magnetic properties and that comprises a magnetic permeability of greater than 1.

2. A power conductor according to claim 1, characterised in that said conductor comprises a second outer layer (12) with insulating properties .

3. A power conductor according to claim 2 , characterised in that the second outer layer (12) has magnetic properties and comprises an electrical permittivity of between 1 and 8.

4. A power conductor according to claim 3 , characterised in that the first outer layer (10) abuts conductor 11 and comprises nano-particles including any element from the list of; iron, chromium, nickel, zinc, manganese, yttrium, indium.

5. A power conductor according to claim 1, characterised in that the first outer layer has a magnetic permeability of between 3 and 10,000 and most preferably for AC operation between 3 and 500.

6. A power conductor according to claim 5, characterised in that the first outer layer has properties of a semiconductor including an electrical resistivity of between 1 and 10⁵ ohm-cm.

7. A power conductor according to claim 2 , characterised in that the first outer layer and the second outer layer each comprise micro-particles with a particle size of between 1 nm and 50μm any of which may be coated or uncoated.

8. A power conductor according to any previous claim, characterised in that said conductor comprises a first outer layer with magnetic permeability greater than 1 and a second outer layer with electric permittivity greater than 1.

9. A power conductor according to claim 8, characterised in that the first outer layer and the second outer layer comprise micro-particles formed with a shape of any from the list of: spherical, ellipsoidal, elongated, plate-like, cylindrical.

10. A power conductor according to claim 9, characterised in that the micro-particles comprise nano-particles with a size of between lnm and 500nm.

11. A power conductor according to claim 10, characterised in that the micro-particles comprise particles with a size of between 0.1 and 50μm.

12. A power conductor according to any of claims 7-11, characterised in that the micro-particles comprise particles with a plurality of sizes of between lnm and 50μm.

13. A power conductor according to any of claims 7-12, characterised in that the micro-particles and nano-particles are arranged distributed in the first outer layer and/or the second outer layer in a substantially homogenous distribution.

14. A power conductor according to any of claims 7-12, characterised in that the micro-particles and nano-particles are arranged homogenously distributed at each level of depth of the first and/or second outer layers and that the concentration of micro-particles and nano-particles may vary at different depths in said layers .

AMENDED SHEET (ARTICLE 19)

15. A power conductor according to any of claims 2-14, characterised by a third outer layer (13, 13') enclosing the second and insulating layer (12) which comprises a semiconducting material with distributed magnetic particles, which layer forms an insulation screen.

16. A power conductor according to any of claims 10-15, characterised by magnetic means (73, 75) for smoothing voltage transients (71) .

17. A power conductor according to claim 16, characterised by magnetic areas or rings (73, 75) in or on an insulating layer

(12, 12') or semiconducting layer (13, 13') arranged to form areas of discrete changes in wave impedance for smoothing voltage transients.

18. A power conductor according to claim 16, characterised in that discrete magnetic areas or rings (73, 75) are arranged separated by a distance dependent on a wavelength of a transient.

19. A power conductor according to any of claims 8 to 15, characterised in that the first outer layer (10, 10a) comprises magnetic material in a linear form and is arranged wrapped around a conductor (11, 11a) of said power conductor.

20. A power conductor according to claim 19, characterised in that the first outer layer (10, 10a) is arranged to have a greater length than the length of the conductor (11, 11a) over a given length of said power conductor.

21. A power conductor according to claim 19, characterised in that the first outer layer (10, 10a) wrapped radially around a conductor (11, 11a) of said power conductor in a direction (14) dependent on the axial direction (19) of power transmission.

AMENDED SHEET (ARTICLE 19)

22. A power conductor according to claim 19, characterised by an outer magnetic shield (83) comprising one or more airgaps .

23. A system for high voltage transmission (1) transmitting electric power between two points (A, B) at least one of which is connected to one or more power networks, characterised in that at least one cable or wire of said system is arranged with a first outer layer (10) that comprises nano-particles and has magnetic properties and that comprises a magnetic permeability of greater than 1.

24. A system according to claim 23, characterised in that the at least one cable or wire comprises magnetic nano-particles distributed in a layer (10) surrounding a conductor (11, 11a) , whereby the transmitted power includes a reduced proportion of reactive power and capacitive losses under AC operation and reduced high frequency harmonics under DC operation.

25. A system according to claim 23, characterised in that at least one cable or wire for transmission of said system is arranged with a second and insulating outer layer (12, 12') comprising distributed magnetic nano-particles, thereby having an insulator with decreased electrical permittivity, whereby the transmitted AC power comprises reduced reactive power and minimized losses due to capacitive leakage currents.

26. A system according to claim 23, characterised in that impedance of said conductor is increased close to that of a wave impedance value in order to give reduced transport of reactive power in the cable lines under AC operation.

27. A system according to claim 23, characterised in that at least one cable or wire for transmission of said system is arranged with a first outer layer (10, 10a) comprising magnetic

AMENDED SHEET (ARTICLE 19) material and wrapped around a conductor (11, Ha) and having a length greater than the conductor (11, 11a) .

28. A system according to claim 23, characterised in that at least one cable or wire for transmission of said system is arranged with one or more series of pluralities of magnetic areas (73, 75) in which the magnetic areas or rings are separated by a distance dependent on a transient wavelength.

29. A system according to claim 23, characterised in that said power conductor has a first outer layer (10, 10a) arranged to reduce high frequency harmonics under DC operation.

30. A system according to claim 23, characterised in that one or more AC transmission cables may be an oil and paper insulated cable.

31. A system according to claim 23, characterised in that said one or more AC or DC transmission cables may be insulated with a polymer, elastomer or other plastic-based material.

32. Use of a system for high voltage transmission (1) for transmitting power between two points (A, B) according to claims 23-31 as a power feeder for large, densely populated urban or suburban areas.

33. Use of a system for high voltage transmission (1) for transmitting power over a distance between two points (A, B) according to claims 23-31 in which a part of the distance is across water.

AMENDED SHEET (ARTICLE 19)

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34. A power conductor for transmitting high voltage electric power between two points (A, B) at least one of which is connected to one or more power networks, characterised in that said conductor comprises a first outer layer (10) that comprises nano-particles and has magnetic properties and that comprises a magnetic permeability of greater than 1, and a second outer layer (12) with insulating properties.

35. A system for high voltage transmission (1) transmitting electric power between two points (A, B) at least one of which is connected to one or more power networks, characterised in that at least one cable or wire of said system is arranged with a first outer layer (10) that comprises nano-particles and has magnetic properties and that comprises a magnetic permeability of greater than 1, and a second outer layer (12) with insulating properties .

AMENDED SHEET (ARTICLE 19)

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