Member for potential equalising
(19)AUSTRALIAN PATENT OFFICE (54) Title Member for potential equalising (51)6 International Patent Classification(s) H02G 013/00 F03D 011/00 (21) Application No: 2003304681 (22) Application Date: 2003.10.31 (87) WIPO No: WO05/050808 (43) Publication Date : 2005 .06.08 (43) Publication Journal Date : 2005 .09.01 (71) Applicant(s) Vestas Wind Systems A/s (72) Inventor(s) Hibbard, Paul?(-1-1) Application NoAU2003304681 A1(19)AUSTRALIAN PATENT OFFICE (54) Title Member for potential equalising (51)6 International Patent Classification(s) H02G 013/00 F03D 011/00 (21) Application No: 2003304681 (22) Application Date: 2003.10.31 (87) WIPO No: WO05/050808 (43) Publication Date : 2005 .06.08 (43) Publication Journal Date : 2005 .09.01 (71) Applicant(s) Vestas Wind Systems A/s (72) Inventor(s) Hibbard, Paul?-1- A member for potential equalising in a wind turbine blade between a first conducting member, such as a member comprising carbon fibres, and a second conducting member, such as a lightning conductor is provided. Furthermore, methods for manufacturing of such members for potential equalising are provided. The member for potential equalising comprises a first contact part suitable for connection to a conducting member comprising carbon fibres, a second contact part and an electrical conductor between the contact parts and the first contact part, wherein the first contact part is shaped substantially as a ribbon. A member for potential equalising between a first conducting member and a second conducting member of a wind turbine blade comprising an electrical conductor, a first contact part for providing a potential equalising connection between said first conducting member of said wind turbine blade and said electrical conductor, a second contact part for providing a potential equalising connection between a second conducting member of said wind turbine blade and said electrical conductor, wherein said first contact part is shaped substantially as a ribbon and said first conducting member comprises carbon fibres.
A member for potential equalising according to claim 1, wherein said first contact part comprises a conducting metal ribbon such as e.g. a flexible sheet or a flexible mesh.
A member for potential equalising according to any one of the claims 1 to 2, wherein said conducting metal ribbon has a width of more than 1 cm, preferably said conducting metal ribbon has a width of between 2 to 30 cm, more preferably said conducting metal ribbon has a width of between 3 to 10 cm, such as 5 cm.
A member for potential equalising according to any one of the claims I to 3, wherein said first contact part further comprises a contact-enhancing layer connected to the side of said conducting metal ribbon to be oriented towards said first conducting member.
A member for potential equalising according to claim 4, wherein said contactenhancing layer extends beyond the conducting metal ribbon in at least one direction in the plane of the conducting metal ribbon.
A member for potential equalising according to any one of the claims I to 5, wherein said first contact part further comprises a cover layer connected to the side of said conducting metal ribbon to be oriented away from said first conducting member.
A member for potential equalising according to claim 6, wherein said cover layer extends beyond the conducting metal ribbon in at least one direction in the plane of the conducting metal ribbon.
A member for potential equalising according to any one of the claims 4 to 7, having a contact-enhancing layer and a cover layer, wherein said contactenhancing layer and said cover layer extend beyond the conducting metal ribbon in at least two directions in the plane of the conducting metal ribbon and said contact-enhancing layer extends beyond said cover layer in at least two directions in the plane of the conducting metal.
A member for potential equalising according to any one of the claims 4 to 8, wherein said cover layer and/or said contact-enhancing layer is a flexible and conductive material, more preferably said contact-enhancing layer comprises a loose non-woven material such as e.g. a web, a veil or a fleece material.
A member for potential equalising according to any one of the claims 4 to 9, wherein said cover layer and/or said contact-enhancing layer is at least partially impregnated with a resin such as a prepreg or a semi-preg, preferably a singleside-impregnated semi°preg.
A member for potential equalising according to any one of the claims i to 10, wherein said second contact part comprises a clamp for connecting to a lightning conductor, preferably a clamp for connection to a lightning conductor cable.
A member for potential equalising according to any one of the claims 1 to 10, wherein said second contact part is substantially equivalent to said first contact part.
A member for potential equalising according to any one of the claims 1 to 12, wherein said electrical conductor is a conducting metal ribbon.
A member for potential equalising according to claim 13, wherein said conducting metal ribbon is a part of and/or an extension of said conducting metal ribbon of said electrical conductor.
A member for potential equalising according to any one of the claims 2 to 14, wherein said conducting metal ribbon and said electrical conductor are good conductors and relatively inert, preferably said conducting metal ribbon and/or said electrical conductor comprise a metal selected from the group consisting of copper, steel, stainless steel, aluminium, nickel, chromium, tin and silver, more preferably said conducting metal ribbon and/or said electrical conductor comprise copper.
A member for potential equalising according to any one of the claims 4 to 10, wherein at least one of said cover layer and/or contact-enhancing layer is a good conductor and relatively inert, preferably said cover layer and/or said contactenhancing layer comprise a metal selected from the group consisting of copper, steel, stainless steel, aluminium, nickel, chromium, tin and silver, more preferably said cover layer and/or said contact-enhancing layer comprise stainless steel.
A member for potential equalising according to any one of the claims 15 to 16, wherein at least one of said conducting metal ribbon, cover layer, said contactenhancing layer and said electrical conductor comprises a combination of materials.
A member for potential equalising according to claim 17, wherein said combination of materials is inhomogeneous, preferably - a layered structure, such as silver-coated tin or silver-coated copper, and/or - a structure with particulate integrated material, such as a metal with a filler or a polymer with carbon black or metal particles, and/or - a structure comprising fibres, such as glass fibres, aramid fibres and/or carbon fibres.
A member for potential equalising according to any one of the claims I to 16 further comprising at least one further contact part for providing a potential equalising connection between one or more further conducting members of said wind turbine blade and said electrical conductor. 20. A member for potential equalising according to any one of the claims 1 to 19, wherein said first contact part is adapted to provide a potential equalising connection to said first conducting member, characterised in that said first conducting member comprises fibres such as reinforcement fibres in a carbon-fibre and/or glass-fibre reinforced plastic, preferably a significant part of the conductance of said first conducting member is provided for by a carbon fibre component of said first conducting member.
A member for potential equalising according to any one of the claims l to 20, wherein said conducting metal ribbon is oriented substantially orthogonal to at least some of the carbon fibres of said first conducting member, preferably said conducting metal ribbon is oriented substantially orthogonal to the main orientation of the carbon fibres of said first conducting member.
A member for potential equalising substantially as hereinbefore described with reference to the accompanying drawings.
A wind turbine blade comprising a member for potential equalising according to any one of the claims 1 to22, - a first conducting member connected to said first contact part of said member for potential equalising, said first conducting member optionally comprising carbon fibres and - a second conducting member connected to said second contact part of said member for potential equalising.
A wind turbine blade comprising a number of members for potential equalising according to any one of the claims 1 to 22, said members for potential equalising connected to said first and second conducting members are positioned at regular or irregular intervals along the length of said wind turbine blade.
Use of a member for potential equalising according to any one of the claims i to 22 for potential equalising of conducting members of a wind turbine blade.
Use of a number of members for potential equalising according to any one of the claims 1 to 22 for potential equalising of two or more conducting members of a wind turbine blade at regular or irregular intervals along the length of said wind turbine blade.
Use of a member for potential equalising according to any one of the claims 1 to 22 for transferring at least a part of a lightning current to a lightning conductor, such as from a conducting member comprising carbon fibres to a lightning conductor cable.
A method for manufacturing of a member for potential equalising according to any one of the claims 1 to 22, comprising the steps of:
providing a contact-enhancing layer at and/or near a first contact part, providing a conducting metal ribbon at least in said first contact part, providing an electrical conductor, - optionally providing a cover layer at and/or near said first contact part, and - providing a second contact part.
A method for manufacturing of a member according to any one of the claims 1 to 22, comprising the steps of:
- providing a first conducting member to be potential-equalised, - providing a contact-enhancing layer at least partially in contact with said first conducting member, - providing a conducting metal ribbon in contact with at least a part of said first conducting member and/or said optional contact-enhancing layer, providing an electrical conductor optionally providing a cover layer in contact with said conducting metal ribbon, and providing a second contact part.
A method for manufacturing according to any one of the claims 28 to 29, wherein said conducting metal ribbon and said electrical conductor are integrated.
A method for manufacturing according to any one of the claims 28 to 30, wherein at least one of said contact-enhancing layer and said optional cover layer is a prepreg, a semi-preg or a dry loose non-woven material such as a web, a veil or a fleece material, preferably a single-side-impregnated semi-preg.
A method for manufacturing according to any one of the claims 28 to 31, further comprising the step of:
providing a resin and/or an adhesive in contact with said contactenhancing layer and/or said conducting metal ribbon and/or said cover layer.
A method for manufacturing according to any one of the claims 28 to 32, further comprising the step of:
- pre-consolidating said member for potential equalising.
A method for manufacturing according to any one of the claims 28 to 33, further comprising the step of:
- curing said member for potential equalising, optionally by a cocuring process wherein said member for potential equalising and at least a part of said wind turbine blade are cured together.