There is provided a method of avoiding edgewise vibrations during a non-operational period of a wind turbine. The method comprises defining a non-operational period for a wind turbine arranged at a specific site, determining expected wind conditions at the specific site during the non-operational period and defining a plurality of potential yaw orientations for the wind turbine. The method further comprises determining the relative probability of edgewise vibrations occurring during the non-operational period for each potential yaw orientation based upon the expected wind conditions during the non-operational period, determining one or more preferred yaw orientations, which are the yaw orientations in which the probability of edgewise vibrations occurring is lowest, and arranging the wind turbine in one of the preferred yaw orientations during the non-operational period.

Invention relates to renewable Wind energy combining drag and lift forces into usable torque, having adjustable blades panels with sub blades. Its unique feature is to convert reverse drag into usable lift and combine the two forces in to one cohesive force. The system comprises output drive rotor arranged on a tower base, with its rotating arms with blade panel assemblies mounted rotatably. Each blade panel assembly comprises an auxiliary rotary shaft having sub-blade panels pivotable at one or more pivot points with primary or secondary control arrangements for blocking and/or allowing wind to pass through the blade panels partially or fully. The system further includes sensors to collect control information, coupled to Main Control Unit (MCU) and secondary control arrangements, configured to provide one or more energy forms.

A wind turbine drive control device according to one aspect of the present invention is a wind turbine drive control device for controlling at least one drive device for moving two structures included in a wind power generation device relative to each other, the wind turbine drive control device including: an obtaining unit for obtaining information related to a load occurring between the at least one drive device and one of the two structures that receives a force generated by the at least one drive device; and a control unit for controlling the at least one drive device so as to cause a force generated by the at least one drive device to be reduced or zero based on the information related to the load obtained by the obtaining unit during a stop period in which the two structures are stopped relative to each other.

A method for controlling a multirotor wind turbine comprising two or more energy generating units is disclosed. At least one load carrying structure is connected to a foundation or to a tower via a yaw arrangement, and the load carrying structure carries the at least two energy generating units. A requirement to a change in operation of at least a first of the energy generating units is detected. Control commands for the first energy generating unit and for at least a second energy generating unit, mounted on the same load carrying structure, are generated. The control commands cause the required change in operation, and the control commands cause coordinated operation of at least the first energy generating unit and the second energy generating unit. The control commands are generated under the constraint that a yaw moment of the yaw arrangement is maintained below a predefined threshold level.

The present invention relates to methods, apparatus and computer program products for controlling a wind turbine that comprises a nacelle and one or more turbine blades to reduce or prevent edgewise vibrations building up on the one or more turbine blades. It is identified 202 whether the nacelle is unable to yaw to an upwind position and initiating a corrective action 203 to prevent edgewise vibrations building up on the one or more turbine blades if the nacelle is unable to yaw to an upwind position.

A method and a system for managing loads on a wind turbine are provided. The method includes receiving a signal relative to a yaw misalignment of the wind turbine, generating a yaw error signal based on the yaw misalignment, and comparing the yaw error signal to a first predetermined yaw error threshold value. The method also includes regulating a speed of the rotor to a value determined by a predetermined tip speed ratio, reducing the yaw misalignment using a yaw control system, and restarting the wind turbine if the yaw error signal is reduced to less than a second predetermined yaw error threshold value within a predetermined period of time. The method further includes shutting down the wind turbine if the yaw error signal remains greater than the second predetermined yaw error threshold value beyond the predetermined period of time.

Disclosed is a power generation device (1), comprising a shaft column (11) and at least two blade units (12-17), wherein the blade units (12-17) are sheathed onto the shaft column (11) and capable of rotating around the shaft column (11), the adjacent blade units rotate in opposite rotational directions, each blade unit (12-17) has a plurality of arm portions (121-171) and a plurality of movable blades (122-172), the arm portions (121-171) extend radially outwardly from the shaft column (11), each of the movable blades is connected to one side of the corresponding arm portion and, after passing through a first radial center line (19) of the shaft column (11), expands gradually, and after being expanded, does not interfere with the adjacent blade unit, the first radial center line (19) is parallel to a fluid flow direction, and each of the movable blades is gradually closed after it rotates through a rotation angle. The power generation device (1) can maximize the use of energy in the fluid so as to improve power generation efficiency.

The present invention provides a conveyance device for an energy collector such as a wind turbine, solar collector, or a combination thereof. The conveyance device is configured to orient the energy collector by moving the device to compensate for a change in the source of energy such as a change in power, direction, speed, location and a combination thereof. The conveyance device includes a track configured to be positioned near a support structure such as a telecommunications tower and first and second electrical contacts configured to electrically connect the energy collector to an electrical load. The conveyance device is also configured to receive an energy collector configured to be attached to the track such that the energy collector is movable relative to the track. In this manner, there is provided a device for adjusting the orientation of the wind turbine or solar collector such that it collects energy efficiently.

The present disclosure is directed to systems and methods for de-icing a rotor blade of a wind turbine. The wind turbine has a nacelle mounted atop a tower. The nacelle has a rotor with a rotatable hub having rotor blade mounted thereto. The method includes shutting down the wind turbine in response to detecting ice on the rotor blade. The method also includes positioning the wind turbine in a de-icing position, the de-icing position including at least one of yawing the nacelle of the wind turbine such that the rotor is in a down-wind location of the tower or pitching the rotor blade such that a leading edge of the rotor blade is facing the tower. Another step includes de-icing the rotor blade while the rotor is in the de-icing position.

Systems and methods for increasing operational efficiency of wind turbines, especially offshore wind turbines. The invention discloses systems and methods for reducing the torque needed to rotate a rotor shaft axis with respect to the wind direction. Systems and methods for controlling the rotational speed of the rotor shaft axis are also disclosed.