Abstract: GaN based nanowires are used to grow high quality, discreet base elements with c-plane top surface for fabrication of various semiconductor devices, such as diodes and transistors for power electronics.

Abstract: A hybrid photovoltaic device (1) comprising a thin film solar cell (2) disposed in a first layer (21) comprising an array of vertically aligned nanowires (25), said nanowires having a junction with a first band gap corresponding to a first spectral range. The nanowires (25) form absorbing regions, and non-absorbing regions are formed between the nanowires. A bulk solar cell (3) s disposed in a second layer (31), positioned below the first layer (21), having a junction with a second band gap, which is smaller than said first band gap and corresponding to a second spectral range. The nanowires are provided in the first layer with a lateral density selected a such that a predetermined portion of an incident photonic wave-front will pass through the non-absorbing regions without absorption in the first spectral range, into the bulk solar cell for absorption in both the first spectral range and the second spectral range.

Abstract: GaN based nanowires are used to grow high quality, discreet base elements with c-plane top surface for fabrication of various semiconductor devices, such as diodes and transistors for power electronics.

Abstract: GaN based nanowires are used to grow high quality, discreet base elements with c-plane top surface for fabrication of various semiconductor devices, such as diodes and transistors for power electronics.

Abstract: The present invention relates to a yaw system 5 for a windmill 1, the windmill comprising a tower 2 and a nacelle 3, the tower and the nacelle being joined by the yaw system and the yaw system further comprising a bearing fixed to the tower, on which bearing the nacelle rests and slides in a yawing movement, and at least one yaw motor arranged to allow the nacelle to perform a rotary motion along the bearing, wherein the yaw system 5 further comprises control means 8 for continuously operating the at least one yaw motor in such a way that the yaw motor strives to maneuver the nacelle according to a setpoint.

Abstract: The present invention relates to a control system for a wind turbine, comprising an electrical device that is arranged for being used during normal operation of a wind turbine and a power source that is arranged to be used as an emergency power supply to a blade pitch motor, wherein the blade pitch motor is arranged to test at least one property of said power source. The invention also relates to a method for testing a power source.

Abstract: A device includes at least one nanoscale capillary and means for applying an electric voltage, said means being adapted to create an electric field at least in said capillary when said electric voltage is applied, so that, when said electric voltage is applied, a charged molecule or particle placed within the created electric field can be electrically controlled. A fluidic network structure includes the at least one nanoscale capillary. A method of using and manufacturing the fluidic network structure is also described.

Abstract: GaN based nanowires are used to grow high quality, discreet base elements with c-plane top surface for fabrication of various semiconductor devices, such as diodes and transistors for power electronics.

Abstract: The present invention relates to a method for balancing a wind turbine. The method includes the steps of a) measuring at least one property that is dependent on a motor workload of at least one yaw motor 52 of a soft yaw system 5 during a period of time, b) calculating an unbalance based on the measurement of step a), c) determining a pitch offset angle for at least one turbine blade 41 based on the calculation of step b), and d) changing the pitch of the at least one turbine blade according to the pitch offset angle of step c) for decreasing the unbalance. The present invention also relates to a system for balancing a wind turbine.

Abstract: A method for preventing a possible overspeed of a wind turbine rotor with at least one rotor blade is provided. The method includes detecting a yaw misalignment of the rotor, and imposing a restriction on changes of a pitch angle towards a feathered position of the at least one rotor blade after detecting the yaw misalignment. Further, a wind turbine having a rotor and a control system configured to prevent a possible overspeed of the rotor is provided.

Abstract: The present invention relates to a control system for a wind turbine, comprising an electrical device that is arranged for being used during normal operation of a wind turbine and a power source that is arranged to be used as an emergency power supply to a blade pitch motor, wherein the blade pitch motor is arranged to test at least one property of said power source. The invention also relates to a method for testing a power source.

Abstract: The present invention relates to a method for balancing a wind turbine. The method includes the steps of a) measuring at least one property that is dependent on a motor workload of at least one yaw motor 52 of a soft yaw system 5 during a period of time, b) calculating an unbalance based on the measurement of step a), c) determining a pitch offset angle for at least one turbine blade 41 based on the calculation of step b), and d) changing the pitch of the at least one turbine blade according to the pitch offset angle of step c) for decreasing the unbalance. The present invention also relates to a system for balancing a wind turbine.

Abstract: A method for preventing a possible overspeed of a wind turbine rotor with at least one rotor blade is provided. The method includes detecting a yaw misalignment of the rotor, and imposing a restriction on changes of a pitch angle towards a feathered position of the at least one rotor blade after detecting the yaw misalignment. Further, a wind turbine having a rotor and a control system configured to prevent a possible overspeed of the rotor is provided.

Abstract: A method of adjusting a yaw angle of a wind turbine. The wind turbine includes a nacelle that is rotatably coupled to a tower. The method includes coupling a yaw drive assembly to the nacelle for adjusting an orientation of the nacelle with respect to a direction of wind. A first sensor that is coupled to the wind turbine transmits at least a first monitoring signal that is indicative of an operating condition of the wind turbine to a control system. A yaw angle of the nacelle with respect to the direction of wind is calculated by the control system based at least in part on the first monitoring signal. The yaw drives assembly is operated to adjust a yaw of the nacelle based at least in part on the calculated yaw angle.

Abstract: An electric power generating device comprising a wind power plant 1 with a rotatably turbine shaft 2, a generator 3 connected to a power grid 5, means for rotating the turbine shaft within the generator thus generating AC electrical power, a plurality of frequency converters 4 for converting the frequency of the AC electrical power to the frequency of the power grid, wherein the plurality of frequency converts are electrically connected in parallel in between the generator and the power grid wherein the power generating device further comprises means 48 for registering the amount of power generated in the generator, and means 10 for registering data in the form of the temperature and utilization of each frequency converter respectively, and means for using the registrated data for automatically bringing each of the frequency converters online sequentially and/or means for automatically alternating the order in which the frequency converters are brought online.

Abstract: The present invention relates to a back-up power system 200 for controlling a wind power plant in case of a power outage. The wind power plant includes one or more rotor blades. The back-up power system includes a plurality of electrical energy storage devices 204 connected in a series connection. The back-up power system also includes a DC-to-AC converter which converts DC from the plurality of electrical energy storage devices to AC and supplies the AC to an electrical motor coupled to the one or more rotor blades for controlling the pitch angle of the rotor blades. Further, the back-up power system includes a step-up DC-to-DC converter 201 coupled in series between the plurality of electrical energy storage devices and the DC-to-AC converter. The step-up DC-to-DC converter amplifies the DC voltage supplied by the plurality of electrical energy storage devices and provides the amplified DC voltage to the DC-to-AC converter.

Abstract: A wind turbine (10) is provided. The wind turbine includes a rotor (18), at least one rotor blade (22) coupled to the rotor, and a yaw system (92). The yaw system (92) includes at least one yaw motor (94) for adjusting a yaw angle of the wind turbine (10). The yaw system (92) is configured for generating a yaw drive signal corresponding to at least one of: i) a property from the at least one yaw motor (94); or ii) a control signal for operating the at least one yaw motor. The wind turbine (10) further includes an asymmetric load control assembly (100) configured to receive the yaw drive signal. The asymmetric load control assembly (100) is further configured to mitigate an asymmetric load acting on the rotor (18) using the yaw drive signal. A control system for operating a wind turbine (10) and a method thereof are also provided.

Abstract: The present invention relates to a yaw system 5 for a windmill 1, the windmill comprising a tower 2 and a nacelle 3, the tower and the nacelle being joined by the yaw system and the yaw system further comprising a bearing fixed to the tower, on which bearing the nacelle rests and slides in a yawing movement, and at least one yaw motor arranged to allow the nacelle to perform a rotary motion along the bearing, wherein the yaw system 5 further comprises control means 8 for continuously operating the at least one yaw motor in such a way that the yaw motor strives to manoeuvre the nacelle according to a setpoint.

Abstract: A method of adjusting a yaw angle of a wind turbine. The wind turbine includes a nacelle that is rotatably coupled to a tower. The method includes coupling a yaw drive assembly to the nacelle for adjusting an orientation of the nacelle with respect to a direction of wind. A first sensor that is coupled to the wind turbine transmits at least a first monitoring signal that is indicative of an operating condition of the wind turbine to a control system. A yaw angle of the nacelle with respect to the direction of wind is calculated by the control system based at least in part on the first monitoring signal. The yaw drives assembly is operated to adjust a yaw of the nacelle based at least in part on the calculated yaw angle.