Abstract: The present invention relates to a system and a method for optimal yaw control of a wind turbine, comprising a tower carrying a rotatable nacelle rotated by a yaw motor, which nacelle comprises at least one generator connected by a shaft to a rotor, comprising one or more wings, which nacelle further comprises means for detecting wind direction and wind velocity, which system performs measurement and storing data related to power production, wind velocity and wind direction. The object of this invention is to optimize the yaw position of a nacelle to the wind direction. The object can be fulfilled by power production measured in a positive direction to actual yaw position is accumulated in a first storages related to measured wind direction and that power production measured in a negative direction to actual yaw position is accumulated in a second storages related to measured wind direction. By this system the power production of the wind turbine is optimized by self-calibrating yaw control.

Abstract: The present invention relates to a control system for thrust-limiting of wind turbines, which wind turbine comprises at least one tower, which tower carries at least one nacelle which nacelle comprises a rotating shaft, which shaft is rotated by one or more blades, which blades at pitch regulated by a pitch control system. It is the object of the present invention to reduce mechanical load and stress of a wind turbine. A further object is to reduce the maximal load on tower of a wind turbine. The thrust-limiting control system performs control of the pitch angle, which thrust-limiting control system performs regulation of the pitch angle based on at least a first input from a wind estimator and a second input from a turbulence estimator. By thrust-limiting control, reduction in the maximum mechanical load on a tower, or maybe also a nacelle, can be achieved by a relatively high percentage of the load in a way where it has only very limited influence on the power production of the wind turbine.

Abstract: The present invention relates to a system for dynamic pitch control primarily for wind turbine blades, which system calculates the pitch position of the wind turbine blades independently, which control system performs feedback regulation. The object of the pending patent application is to perform effective pitch regulation and hereby to reduce thrust on the tower and the rotor. This can be achieved if the system performs feed forward regulation of the pitch of the blades, based on the load of the previous blade in substantially the same position. Hereby it can be achieved that the actual load on the previous blade has passed the same position in relation to the wind blowing around the wind turbine. Hereby it can be achieved that measured parameters are used after a short delay to perform a very precise and highly efficient adjustment of the next wind turbine blade passing the same position.

Abstract: A system for electric pitch control primarily for wind turbine blades, has at least one first electric motor which is electrically coupled to a first electronic control device, which electronic control device controls the operation of the motor which drives a gear mechanism via a clutch that has a tooth wheel that drives a tooth ring which is mechanical fixed to the root of a wind turbine blade for performing pitch regulation. To improve the reliability of an electric pitch control system the system has at least one second motor which is electrically coupled to a second electronic control device which is coupled to the power grid and controls the operation of the second motor. The second motor has a shaft which drives a second gear mechanism via clutch. The second gear mechanism has at least one second tooth wheel, which second tooth wheel drives the tooth ring.

Abstract: The present invention relates to the wind power engineering and to the method of controlling a yaw angle of the wind turbine, equipped with a horizontal rotor shaft as well as to the wind turbine for implementing the method. According to the method of the present invention, the time difference between the time moments when the rotor blades are in the lower vertical position, the said time moments derived from the reference signal of the sensor connected to the rotor shaft, and the time moments when the blades are on one line with the wind direction and the tower, the said time moments_derived from the periodic signal of the spurious amplitude modulation generated by the AC generator and caused by aerodynamic interaction between the blades and the tower, is used as the indication of actual position of the wind turbine rotor relative to the wind direction.

Abstract: The invention relates to a procedure of connecting a polyphased asynchronous generator on a polyphased alternating voltage network. The connecting is carried out by means of an adjustable, electronic connecting based on thyristors or similar variable (adjustable) connecting items, the connecting degree of which is varied during a controlled connecting course, which is controlled in consideration of the wish of a “soft” connecting on the network and a limitation of the maximum amperage during the connecting course. During the whole connecting course a continuous determination of the generator phase angle &phgr; is carried out, and on basis of this determination a continuous adjustment of thyristors—the aperture angle is carried out, thus the aimed, successive load connection of the generator on the network (soft-connecting) is obtained.