System and Method for Variation of the Pitch Angle Position of Rotor Blades of a Wind Energy Installation

Abstract

A system for variation of the pitch angle position of rotor blades of a wind energy installation includes drive units, closed-loop control devices, and system control connections. The drive units are in each case individually associated with the rotor blades. The closed-loop control devices are in each case individually associated with the drive units. The system control connections are switchable by switching means. By way of the system control connections, in the event of a failure or a malfunction of at least one closed-loop control device a drive unit which is associated with the at least one closed-loop control device is operated in parallel with and at the same time as another drive unit, by means of a closed-loop control device which is associated with the other drive unit.

1 . A system for altering the pitch of rotor blades of a wind turbine, comprising:
 a plurality of drive units, each drive unit of the plurality of drive units being individually associated with each of the rotor blades;   a plurality of regulating devices, each regulating device of the plurality of regulating devices being individually associated with each drive unit of the plurality of drive units; and   a plurality of activating connections, each activating connection of the plurality of activating connections being switchable by means of switching means,   wherein via the plurality of activating connections, in the event of a failure or a malfunction of at least one regulating device, a drive unit associated with the at least one regulating device is activated in parallel and simultaneously with another drive unit with a regulating device associated with the other drive units.   
     
     
         2 . The system as claimed in  claim 1 , wherein each drive unit of the plurality of drive units has an electromotor and a braking device that are connectable by the switching means simultaneously to the regulating device associated with the other drive units and is disconnectable from the regulating device associated with the other drive units. 
     
     
         3 . The system as claimed in  claim 1 , wherein each drive unit of the plurality of drive units has an electromotor in the form of an asynchronous motor. 
     
     
         4 . The system as claimed in  claim 1 , wherein each drive unit of the plurality of drive units has an electromotor in the form of a synchronous motor. 
     
     
         5 . The system as claimed in  claim 1 , wherein at least one drive unit of the plurality of drive units has a position sensor. 
     
     
         6 . The system as claimed in  claim 5 , further comprising:
 a further regulating device configured to activate the at least one drive unit can be effected in parallel with the other drive unit with the regulating device associated with the other drive unit.   
     
     
         7 . A method for altering the pitch of rotor blades of a wind turbine with a system having drive units individually associated with each of the rotor blades, regulating devices individually associated with each of the drive units, and activating connections that are switchable by means of switching means, comprising:
 activating a drive unit in parallel and simultaneously with another drive unit with a regulating device associated with the another drive unit in the event of failure or a malfunction of at least one other regulating device.    
     
     
         8 . The method as claimed in  claim 7 , further comprising:
 determining the pitches of the rotor blades and synchronizing the pitches by decelerating and/or adjusting motors of the drive units associated with the rotor blades.   
     
     
         9 . The method as claimed in  claim 7 , further comprising:
 reducing an activating power of the motor, when a critical rotor displacement angle of at least one motor of a drive unit is exceeded,   wherein the at least one motor is a synchronous motor, and   wherein the at least one motor is associated with one of the rotor blades.   
     
     
         10 . The method as claimed in  claim 9 , in which further comprising:
 (i) determining a mechanical angle of the motor, (ii) calculating an angle of a related electrical field, and (iii) comparing the mechanical angle with the angle of the electrical field in order to determine a rotor displacement angle of the at least one motor.