Fluid Turbine Lightning Protection System

Abstract

A fluid turbine lightning protection system includes at least one air termination device, formed at least in part of an electrically conductive material, that can be positioned on a shroud of a fluid turbine and placed in electrical communication with a down conduction system. The down conduction system is in electrical communication with an earth-termination system configured to dissipate electricity transferred thereto to the ground. The at least one air termination device is configured to intercept a lightning strike and direct it through the down conduction system, the earth-termination system, and into the ground. The at least one air termination device may be positioned on a turbine shroud based on a “Rolling Sphere” derivation wherein the “Rolling Sphere” derivation is derived from the equation r=10·I 0.65 , where I is the peak current in kiloamperes and r is the rolling sphere radius in meters.

1 . A fluid turbine lightning protection system, comprising:
 at least one air termination device positionable on a shroud of a fluid turbine, the air termination device formed at least in part of an electrically conductive material;   a down conduction system in electrical communication with the at least one air termination device; and   an earth-termination system in electrical communication with the down conduction system, the earth-termination system configured to dissipate electricity to the ground,   wherein the at least one air termination device is configured to intercept a lightning strike.   
     
     
         2 . The fluid turbine lightning protection system of  claim 1 , wherein the at least one air termination device comprises a plurality of air termination devices positioned on the shroud of the fluid turbine and configured to intercept a lightning strike based on a “Rolling Sphere” derivation. 
     
     
         3 . The fluid turbine lightning protection system of  claim 2 , wherein the “Rolling Sphere” derivation is derived from the equation r=10·I 0.65 , where I is defined as the peak current in kiloamperes and r is defined as the rolling sphere radius in meters. 
     
     
         4 . The fluid turbine lightning protection system of  claim 1 , wherein the fluid turbine includes an ejector shroud and at least one air termination device is positionable on the ejector shroud. 
     
     
         5 . The fluid turbine lightning protection system of  claim 1 , wherein the shroud of the fluid turbine further includes:
 an external electrically conductive material; and   an internal electrically conductive material,   wherein the external electrically conductive material is conductively engaged with the internal electrically conductive material, and the internal electrically conductive material is electrically engaged with the down conduction system.   
     
     
         6 . The fluid turbine lightning protection system of  claim 5 , wherein the internal electrically conductive material is in electrical communication with the down conductive system through a electrical wiper system. 
     
     
         7 . The fluid turbine lightning protection system of  claim 5 , wherein the external electrically conductive material is positioned at a leading edge of the turbine shroud. 
     
     
         8 . The fluid turbine lightning protection system of  claim 5 , wherein the internal electrically conductive material is integrated with the surface of the turbine shroud. 
     
     
         9 . The fluid turbine lightning protection system of  claim 4 , wherein the ejector shroud further comprises:
 an external electrically conductive material; and   an internal electrically conductive material,   wherein the external electrically conductive material is conductively engaged with the internal electrically conductive material, and the internal electrically conductive material is electrically engaged with the down conduction system.   
     
     
         10 . The fluid turbine lightning protection system of  claim 9 , wherein the internal electrically conductive material is in electrical communication with the down conductive system through an electrical wiper system. 
     
     
         11 . The fluid turbine lightning protection system of  claim 9 , wherein the external electrically conductive material is positioned at a trailing edge of the ejector shroud. 
     
     
         12 . The fluid turbine lightning protection system of  claim 9 , wherein the internal electrically conductive material is integrated with the surface of the ejector shroud. 
     
     
         13 . A lightning protected fluid turbine, comprising:
 a fluid turbine including a shroud;   at least one air termination device positioned on the shroud of the fluid turbine, the air termination system formed at least in part of an electrically conductive material;   a down conduction system in electrical communication with the at least one air termination device; and   an earth-termination system in electrical communication with the down conduction system, the earth-termination system configured to dissipate electricity to the ground,   wherein the at least one air termination device is configured to intercept a lightning strike so as to prevent the lightning from striking the fluid turbine.   
     
     
         14 . The lightning protected fluid turbine of  claim 13 , wherein the at least one air termination device comprises a plurality of air termination devices positioned on the shroud of the fluid turbine and configured to intercept a lightning strike based on a “Rolling Sphere” derivation. 
     
     
         15 . The lightning protected fluid turbine of  claim 14 , wherein the “Rolling Sphere” derivation is derived from the equation r=10·I 0.65 , where I is defined as the peak current in kiloamperes and r is defined as the rolling sphere radius in meters. 
     
     
         16 . The lightning protected fluid turbine of  claim 13 , wherein the fluid turbine includes an ejector shroud and at least one air termination device is positionable on the ejector shroud. 
     
     
         17 . The lightning protected fluid turbine of  claim 13 , wherein the shroud of the fluid turbine further includes:
 an external electrically conductive material; and   an internal electrically conductive material,   wherein the electrically conductive material is conductively engaged with the internal electrically conductive material, and the internal electrically conductive material is electrically engaged with the down conduction system.   
     
     
         18 . The lightning protected fluid turbine of  claim 17 , wherein the internal electrically conductive material is in electrical communication with the down conductive system through an electrical wiper system. 
     
     
         19 . The lightning protected fluid turbine of  claim 17 , wherein the external electrically conductive material is positioned at a leading edge of the shroud of the fluid turbine. 
     
     
         20 . The lightning protected fluid turbine of  claim 17 , wherein the internal electrically conductive material is integrated with the surface of the shroud of the fluid turbine. 
     
     
         21 . The lightning protected fluid turbine of  claim 16 , wherein the ejector shroud further includes:
 an external electrically conductive material; and   an internal electrically conductive material,   wherein the electrically conductive material is conductively engaged with the internal electrically conductive material, and the internal electrically conductive material is electrically engaged with the down conduction system.   
     
     
         22 . The lightning protected fluid turbine of  claim 21 , wherein the internal electrically conductive material is in electrical communication with the down conductive system through an electrical wiper system. 
     
     
         23 . The lightning protected fluid turbine of  claim 21 , wherein the external electrically conductive material is positioned at a trailing edge of the ejector shroud. 
     
     
         24 . The lightning protected fluid turbine of  claim 21 , wherein the internal electrically conductive material is integrated with the surface of the ejector shroud. 
     
     
         25 . A method of protecting a fluid turbine from a lightning strike, comprising:
 providing a fluid turbine including a shroud;   determining a peak lightning strike current;   calculating a “Rolling Sphere” circumference or radius based on the equation:
 r=10·I 0.65 , where I is defined as the peak lightning strike current in kiloamperes and r is defined as the rolling sphere radius in meters; and 
   positioning one or more air termination devices on the shroud that are in electrical communication with a down conduction system that is in electrical communication with a earth-termination system,   wherein the one or more air termination devices are positioned on the shroud such that the calculated “Rolling Sphere” contacts the one or more air termination devices before contacting the shroud when the “Rolling Sphere” is rolled along an exterior of the shroud.   
     
     
         26 . The method of protecting a fluid turbine from a lightning strike of  claim 25 , wherein the fluid turbine is provided with an ejector shroud and one or more air termination devices are positioned on the ejector shroud. 
     
     
         27 . The method of protecting a fluid turbine from a lightning strike of  claim 25 , wherein the shroud includes an electrically conductive material integrated therein and in electrical communication with the down conduction system. 
     
     
         28 . The method of protecting a fluid turbine from a lightning strike of  claim 27 , wherein the electrically conductive material is positioned at a leading edge of the shroud. 
     
     
         29 . The method of protecting a fluid turbine from a lightning strike of  claim 27 , wherein the electrically conductive material is integrated with a surface of the shroud.