Method and arrangement for detecting a shadow condition of a wind turbine

Abstract

A method for detecting a shadow condition from a wind turbine and a system for detecting a shadow condition are provided. An atmospheric condition detected from an atmospheric condition detector is compared to a threshold. From the comparison a determination is made that the atmospheric condition is shadow producing. The shadow condition is detected using said determination.

What is claimed is: 
     
         1 . A method of detecting a shadow condition from a wind turbine, the method comprising:
 determining a geometry condition is present which is effective to produce a shadow at a location of concern;   comparing an atmospheric condition, detected by an atmospheric condition detector, to a threshold;   determining the atmospheric condition is shadow producing from the comparison; and   detecting a shadow condition in response to the geometry condition determined to produce a shadow at the location of concern and to the atmospheric condition determined to be shadow producing.   
     
     
         2 . The method of detecting a shadow condition according to  claim 1 ,
 wherein the atmospheric condition is a cloud amount,   the atmospheric condition is determined to be shadow producing in response to the comparison of the cloud amount being below the threshold.   
     
     
         3 . The method of detecting a shadow condition according to  claim 2 ,
 wherein the threshold is overcast.   
     
     
         4 . The method of detecting a shadow condition according to  claim 2 ,
 wherein the threshold is broken.   
     
     
         5 . The method of detecting a shadow condition according to  claim 1 ,
 initiating a shutdown of the wind turbine in response to detecting a shadow condition.   
     
     
         6 . The method of detecting a shadow condition according to  claim 4 ,
 the initiating comprises sending a control message to the wind turbine.   
     
     
         7 . The method of detecting a shadow condition according to  claim 1 , comprising
 determining the geometry condition comprises establishing the location of the sun and determining the established location is within a threshold position.   
     
     
         8 . The method of detecting a shadow condition according to  claim 1 ,
 wherein the atmospheric condition detector includes LIDAR.   
     
     
         9 . The method of detecting a shadow condition according to  claim 1 ,
 wherein the atmospheric condition detector includes RADAR.   
     
     
         10 . The method of detecting a shadow condition according to  claim 1 ,
 wherein the atmospheric condition detector includes SONAR.   
     
     
         11 . The method of detecting a shadow condition according to  claim 1 ,
 wherein the atmospheric condition detector is a ceilometer.   
     
     
         12 . The method of detecting a shadow condition according to  claim 1 ,
 wherein the atmospheric condition comprises a height of the clouds or aerosol.   
     
     
         13 . A shadow detection system comprising:
 a atmospheric condition detector separated from a wind turbine by a distance; and   a controller communicatively coupled to the wind turbine by a network and configured for:
 determining a geometry condition is present which is effective to produce a shadow at a location of concern; 
 comparing an atmospheric condition, detected by an atmospheric condition detector, to a threshold; 
 determining the atmospheric condition is shadow producing from the comparison; and 
 detecting a shadow condition in response to the geometry condition determined to produce a shadow at the location of concern and to the atmospheric condition determined to be shadow producing. 
   
     
     
         14 . The shadow detection system according to  claim 13 ,
 wherein the atmospheric condition is a cloud amount,   the atmospheric condition is determined to be shadow producing in response to the comparison of the cloud amount being below the threshold.   
     
     
         15 . The shadow detection system according to  claim 14 ,
 wherein the threshold is overcast;   
     
     
         16 . The shadow detection system according to  claim 14 ,
 wherein the threshold is broken;   
     
     
         17 . The shadow detection system according to  claim 13 ,
 wherein the atmospheric condition detector is located remotely at a distance from the wind turbine.   
     
     
         18 . The shadow detection system according to  claim 13 ,
 wherein the atmospheric condition detector is a ceilometer.   
     
     
         19 . A wind turbine farm, comprising:
 a plurality of wind turbines; and   a shadow detection system according to according to  claim 13  for detecting shadows for each of the plurality of wind turbines.   
     
     
         20 . The wind turbine farm according to  claim 19 ,
 wherein the atmospheric condition detector is located remotely at a distance from at least one of the plurality of wind turbines.