Methods and apparatus for operating a wind turbine

Abstract

A method for operating a wind turbine having at least one blade includes determining an ambient air operating envelope and controlling a power output of the wind turbine at least partially based on the determined ambient air operating envelope. Determining an ambient air operating envelope includes measuring at least one of an ambient air temperature, an ambient air pressure, an ambient air humidity, and wind turbine power output. The method also includes comparing at least one of a measured ambient air temperature, a measured ambient air humidity and a measured ambient air pressure to predetermined ambient air temperature, pressure and humidity values. The method further includes referencing the predetermined ambient air temperature, pressure and humidity values to at least one operational parameter of the wind turbine. The method also includes determining if an existing wind turbine power output is within a range associated with the determined ambient air operating envelope.

1 . A method for operating a wind turbine, said method comprising:
 measuring an ambient air temperature; and   decreasing a power output of the wind turbine if the measured ambient air temperature is below a predetermined limit to thereby facilitate reducing loads acting on components of the wind turbine.   
     
     
         2 . A method in accordance with  claim 1  wherein the wind turbine is configured to withstand loads acting on the wind turbine within a predetermined ambient air temperature range having lower and upper limits with predetermined wind speed parameters, and wherein decreasing a power output of the wind turbine if the measured ambient air temperature is below a predetermined limit comprises decreasing the power output of the wind turbine if the measured ambient air temperature is below the lower limit of the predetermined ambient air temperature range. 
     
     
         3 . A method in accordance with  claim 1  further comprising decreasing a power output of the wind turbine if the measured ambient air temperature is above a predetermined limit to thereby facilitate reducing a potential for stalling of the wind turbine. 
     
     
         4 . A method in accordance with  claim 3  wherein the wind turbine is configured to mitigate the potential for stalling the wind turbine within a predetermined ambient air temperature range having lower and upper limits with predetermined wind speed parameters, and wherein decreasing a power output of the wind turbine if the measured ambient air temperature is above a predetermined limit comprises decreasing the power output of the wind turbine if the measured ambient air temperature is above the upper limit of the predetermined ambient air temperature range. 
     
     
         5 . A method in accordance with  claim 1  wherein decreasing a power output of the wind turbine comprises increasing a pitch angle of at least one rotor blade of the wind turbine. 
     
     
         6 . A method in accordance with  claim 1  wherein decreasing a power output of the wind turbine comprises decreasing a torque acting on a generator rotor of the wind turbine. 
     
     
         7 . A wind turbine comprising:
 a rotor comprising a hub and at least one rotor blade coupled to said hub;   a first sensor configured to measure ambient air temperature and generate and transmit an ambient air temperature signal; and   at least one processor coupled in electronic data communication to said first sensor, said at least one processor configured to facilitate reducing loads acting on components of said wind turbine by at least one of:
 receiving a measured ambient air temperature signal from said first sensor; 
 decreasing a power output of the wind turbine if the received ambient air temperature signal is below a predetermined limit. 
   
     
     
         8 . A wind turbine in accordance with  claim 7  further comprising at least one of:
 at least one blade pitch actuator coupled to said at least one rotor blade for controlling an angle of pitch of said at least one rotor blade and coupled in electronic data communication to said at least one processor, said at least one processor further configured to increase a pitch angle of said at least one rotor blade using said at least one blade pitch actuator when the ambient air temperature signal is below the predetermined limit; and   an electric power generation sub-system comprising at least one of an electric power generator and a frequency converter, said electric power generator comprising a stator, a rotor and a gap defined therebetween, said electric power generator electrically coupled to said frequency converter, said electric power generator and said frequency converter coupled in electronic data communication with said processor, said processor further configured to decrease a torque acting on said rotor induced within said gap when the ambient air temperature signal is below the predetermined limit.   
     
     
         9 . A wind turbine in accordance with  claim 7  wherein said at least one processor is further configured to facilitate mitigating a potential for stalling said wind turbine by decreasing a power output of the wind turbine if the ambient air temperature signal is above a predetermined limit. 
     
     
         10 . A wind turbine in accordance with  claim 7  further comprising at least one of:
 a second sensor configured to measure ambient air pressure and generate and transmit an ambient air pressure signal, said second sensor coupled in electronic data communication with said at least one processor; and   a third sensor configured to measure ambient air humidity and generate and transmit an ambient air humidity signal, said third sensor coupled in electronic data communication with said at least one processor.   
     
     
         11 . A wind turbine in accordance with  claim 10  wherein said at least one processor is further configured to:
 determine an ambient air operating envelope at least partially based on at least one of said ambient air temperature signal, said ambient air pressure signal, and said ambient air humidity signal; and   decrease the power output of said wind turbine at least partially based on said determined ambient air operating envelope.   
     
     
         12 . A wind turbine in accordance with  claim 7  wherein said predetermined limit comprises a lower limit of a predetermined ambient air temperature range referenced to a predetermined wind speed range, for which said wind turbine is configured to withstand loads acting thereon. 
     
     
         13 . A wind turbine in accordance with  claim 7  wherein said predetermined limit comprises an upper limit of a predetermined ambient air temperature range referenced to a predetermined wind speed range, for which said wind turbine is configured to mitigate a potential for stalling. 
     
     
         14 . A method for operating a wind turbine having at least one blade, said method comprising:
 determining an ambient air operating envelope; and   controlling a power output of the wind turbine at least partially based on the determined ambient air operating envelope.   
     
     
         15 . A method in accordance with  claim 14  wherein determining an ambient air operating envelope comprises:
 measuring at least one of an ambient air temperature, an ambient air pressure, an ambient air humidity, and wind turbine power output; and   comparing at least one of a measured ambient air temperature, a measured ambient air humidity and a measured ambient air pressure to predetermined ambient air temperature, pressure and humidity values; and   referencing the predetermined ambient air temperature, pressure and humidity values to at least one operational parameter of the wind turbine.   
     
     
         16 . A method in accordance with  claim 15  wherein referencing the predetermined ambient air temperature, pressure and humidity values to at least one operational parameter of the wind turbine comprises referencing the predetermined ambient air temperature, pressure and humidity values to at least one of a predetermined range of blade rotational speeds and a predetermined range of wind turbine power outputs. 
     
     
         17 . A method in accordance with  claim 14  further comprising determining if an existing wind turbine power output is within a range associated with the determined ambient air operating envelope. 
     
     
         18 . A method in accordance with  claim 14  wherein controlling a power output of the wind turbine comprises at least one of:
 controlling a pitch angle of at least one rotor blade of the wind turbine at least partially based on the ambient air operating envelope; and   controlling a torque of a generator rotor of the wind turbine at least partially based on the ambient air operating envelope.   
     
     
         19 . A method in accordance with  claim 14  wherein the wind turbine is configured to withstand loads acting on the wind turbine within at least one of a predetermined ambient air temperature range, a predetermined ambient air pressure range and a predetermined ambient air humidity range, wherein each of the temperature, pressure and humidity ranges have lower and upper limits referenced to at least one of predetermined wind speed parameters and predetermined wind turbine power outputs, and wherein controlling a power output of the wind turbine at least partially based on the determined ambient air operating envelope comprises decreasing the power output of the wind turbine to facilitate withstanding loads acting thereon. 
     
     
         20 . A method in accordance with  claim 14  wherein the wind turbine is configured to mitigate stalling of the wind turbine within at least one of a predetermined ambient air temperature range, a predetermined ambient air pressure range and a predetermined ambient air humidity range, wherein each of the temperature, pressure and humidity ranges have lower and upper limits referenced to at least one of predetermined wind speed parameters and predetermined wind turbine power outputs, and wherein controlling a power output of the wind turbine at least partially based on the determined ambient air operating envelope comprises decreasing the power output of the wind turbine to facilitate mitigating a potential for stalling thereon.