Lightning protection system for a wind turbine
View Patent ↗In a wind turbine ( 104, 500, 704 ) having a plurality of blades ( 132, 404, 516, 744 ) and a blade rotor hub ( 120, 712 ), a lightning protection system ( 100, 504, 700 ) for conducting lightning strikes to any one of the blades and the region surrounding the blade hub along a path around the blade hub and critical components of the wind turbine, such as the generator ( 112, 716 ), gearbox ( 708 ) and main turbine bearings ( 176, 724 ).
1. A wind turbine, comprising:
a) a wind rotor comprising a wind rotor hub and a plurality of blades attached to the wind rotor hub, said wind rotor hub having a rotational axis and first and second sides spaced from each other along said rotational axis, each of said plurality of blades including a non-conductive portion proximate said blade rotor hub and at least one conductive portion radially outward from said rotational axis beyond said non-conductive portion;
b) an electrically grounded structure located on said second side of said wind rotor hub and stationary about said rotational axis when said wind rotor is in use; and
c) a lightning conducting path of least electrical resistance extending from said at least one conductive portion of each of said plurality of blades to said electrically grounded structure, said lightning conducting path spaced from said wind rotor hub so as to inhibit arcing between said lightning conducting path and said wind rotor hub.
2. A wind turbine according to claim 1 , wherein said lightning conductive path includes an electrical hub located at least partially on said first side of said wind rotor hub.
3. A wind turbine according to claim 2 , wherein said electrical hub comprises a plurality of elongate electrical conductors.
4. A wind turbine according to claim 3 , wherein said elongate conductive structures are cables.
5. A wind turbine according to claim 2 , wherein said electrical hub comprises a conductive ring located proximate said electrically grounded structure.
6. A wind turbine according to claim 2 , further comprising a nose cone substantially enclosing said wind rotor hub, said nose cone integrating said electrical hub.
7. A wind turbine according to claim 1 , wherein said lightning conductive path includes a plurality of elongate electrical conductors corresponding respectively to said plurality of blades, each said plurality of elongate electrical conductors having a first end in electrical communication with said at least one conductive portion of the corresponding one of said plurality of blades and a second end located proximate said electrically grounded structure.
8. A wind turbine according to claim 7 , wherein each of said plurality of elongate electrical conductors is a cable.
9. A wind turbine according to claim 7 , wherein said plurality of elongate electrical conductors at least partially form an electrical hub that extends partially around said wind rotor hub.
10. A wind turbine according to claim 9 , wherein said plurality of elongate electrical conductors cross one another on said first side of said wind rotor hub.
11. A wind turbine according to claim 9 , wherein said plurality of elongate electrical conductors are electrically coupled with one another.
12. A wind turbine according to claim 9 , wherein said electrical hub comprises a conductive ring located proximate said electrically grounded structure.
13. A wind turbine according to claim 1 , wherein said electrically grounded structure is a generator housing.
14. A wind turbine according to claim 1 , wherein said electrically grounded structure is a nacelle.
15. A wind turbine according to claim 1 , wherein said electrically grounded structure is a generator support structure.
16. A wind turbine according to claim 1 , wherein said lightning conducting path comprises at least one spark gap between said wind rotor and said grounded structure.
17. A wind turbine according to claim 16 , wherein said lightning conducting path further comprises at least one elongate electrical conductor having an end that forms part of said at least one spark gap.
18. A wind turbine according to claim 1 , wherein said lightning conducting path comprises a plurality of spark gaps located proximate said electrically grounded member and arranged so that at least one of said plurality of spark gaps will conduct a lightning strike regardless of the deflection of said wind rotor.
19. A wind turbine according to claim 1 , wherein each of said plurality of blades has a length and comprises a plurality of conductive portions spaced from one another along said length.
20. A wind turbine according to claim 1 , wherein said wind rotor further comprises a nose cone and said lightning conducting path comprises an electrical hub located between said blade rotor hub and said nose cone.
21. A wind turbine according to claim 1 , wherein said lightning conducting path comprises an electrical hub and said wind rotor further comprises a nose cone located between said electrical hub and said blade rotor hub.
22. A wind turbine, comprising:
a) a blade rotor hub having a rotational axis and a front side;
b) a plurality of blades each attached to said blade rotor hub and including a non-conductive portion proximate said blade rotor hub and at least one conductive portion radially outward from said rotational axis beyond said non-conductive portion; and
c) a lightning conductive path extending from said at least one conductive portion of each of said plurality of blades to an electrical ground when the wind turbine is grounded to the electrical ground, said lightning conductive path including an electrical hub at least partially located on said front side of said blade rotor hub and spaced from the blade rotor hub.