Lightning protection system for wind turbine blades with an effective injection area to carbon fiber laminates and a balanced lightning current and voltage distribution between different conductive paths

Patent metadata

Field	Value
Publication number	US-2016369781-A1
Application number	US-201615173896-A
Country	US
Kind code	A1
Filing date	Jun 6, 2016
Priority date	Jun 17, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

A lightning protection system for a wind turbine blade with one or two carbon fiber laminates and one or more down conductors equipotentialized with them by one or more auxiliary cables comprising at least one local lightning current injection area in the carbon fiber laminates associated with one auxiliary cable having secondary cables derived from the auxiliary cable and connected to conductive devices embedded in the carbon fiber laminates which are configured for avoiding overcurrents in the carbon fiber laminates. The invention also provides a lightning protection system for achieving a balanced distribution of currents and voltages between the down conductors and the carbon fiber laminates.

First claim

1 . A lightning protection system for a wind turbine blade ( 10 ) comprising at least a lightning receptor ( 15 ) connected to one or more down conductors ( 17 ) of a grounding arrangement of the wind turbine blade ( 10 ) and one or two carbon fiber laminates ( 11 , 13 ); the down conductors ( 17 ) being equipotentialized with the carbon fiber laminates ( 11 , 13 ) by one or more auxiliary cables ( 19 ) which are connected to conductive plates ( 31 ) embedded in the carbon fiber laminates ( 11 , 13 ) at various points along the wind turbine blade ( 10 ); characterized in that further comprises at least one local lightning current injection area ( 14 ) in the carbon fiber laminates ( 11 , 13 ) associated to one auxiliary cable ( 19 ) having one or more additional parallel conductive paths comprising secondary cables ( 33 ) derived from said auxiliary cable ( 19 ) and connected to conductive devices ( 45 ) embedded in the carbon fiber laminates ( 11 , 13 ) which are configured for avoiding overcurrents in the carbon fiber laminates ( 11 , 13 ).

2 . A lightning protection system according to claim 1 , comprising at least a resistor ( 41 ) in one secondary cable ( 33 ) of a local lightning current injection area ( 14 ).

3 . A lightning protection system according to claim 2 , wherein the resistance of said resistor 41 is comprised between 2-50 mΩ.

4 . A lightning protection system according to claim 1 , comprising at least two secondary cables ( 33 ) having different resistances R cond1 , R cond2 in a local lightning current injection area ( 14 ).

5 . A lightning protection system according to claim 1 , comprising at least two conductive devices ( 45 ) having different resistances R pl1 , R pl2 in one local lightning current injection area ( 14 ).

6 . A lightning protection system according to claim 5 , wherein said conductive devices ( 45 ) are conductive plates made of one of the following materials: steel alloys, copper, aluminium, brass, tungsten, nichrome, conductive composite materials and non-conductive composite materials with conductive additives.

7 . A lightning protection system according to claim 5 , wherein one of said conductive devices ( 45 ) is an ensemble of a conductive plate ( 51 ) and a metallic mesh ( 53 ).

8 . A lightning protection system according to claim 1 , comprising at least two additional conductive parallel paths wherein their conductive devices ( 45 ) are separated by a distance D between 10-300 cm.

9 . A lightning protection system according to claim 1 , wherein
the wind turbine blade ( 10 ) comprises one carbon fiber laminate ( 11 ); the lightning protection system is designed for a reference value of the impedance of the carbon fiber laminate ( 11 ); the lightning protection system further comprises one or more impedance devices ( 25 ) in said auxiliary cables ( 19 ) in the case of existing a negative difference exceeding a predetermined threshold between the impedance of the carbon fiber laminate ( 11 ) and said reference value; said one or more impedance devices ( 25 ) are configured for achieving a balanced distribution of currents and voltages between the one or more down conductors ( 17 ) and the carbon fiber laminate ( 11 ).

10 . A lightning protection system according to claim 9 , wherein said impedance devices ( 25 ) comprise one or more of the following passive elements: a resistor, an inductor, a capacitor.

11 . A lightning protection system according to claim 1 , wherein
the wind turbine blade ( 10 ) comprises two carbon fiber laminates ( 11 , 13 ); the lightning protection system further comprises one or more impedance devices ( 25 ) in said auxiliary cables ( 19 ) in the case of existing a difference exceeding a predetermined threshold between the impedances of the carbon fiber laminates ( 11 , 13 ); said one or more impedance devices ( 25 ) are configured for achieving a balanced distribution of currents and voltages between the one or more down conductors ( 17 ) and the carbon fiber laminates ( 11 , 13 ).

12 . A lightning protection system according to claim 11 , wherein said impedance devices ( 25 ) comprise one or more of the following passive elements: a resistor, an inductor, a capacitor.

Assignees

• Gamesa Innovation & Tech Sl

Inventors

• March Nomen Victor
• Montanya Puig Joan

Classifications

• F03D80/30 Primary

  Lightning protection · CPC title

• F03D1/0675 Primary

  of the blades · CPC title

• F05B2280/6013

  Fibres · CPC title

• F05B2280/1071

  Steel alloys · CPC title

• F05B2280/105

  Copper · CPC title