Abstract: A method (1000, 2000, 3000) for operating a wind turbine (100-100d) is disclosed. The wind turbine includes a power conversion system (114, 118, 210, 234, 410, 420, 430) configured to provide electrical output power (P) to a grid (242), and an air-cooling system (450) configured, in a cooling mode, to cool an ambient air (28a) and provide the cooled ambient air as a cooling air (28c) to the power conversion system (114, 118, 210, 234, 410, 420, 430). The method (1000, 2000, 3000) includes operating (1100, 2100, 3100) the air-cooling system (450) in the cooling mode if at least one operating parameter (APD, RPD, TGB, TBS) of the power conversion system (114, 118, 210, 234, 410, 420, 430) is equal to or greater than a respective threshold (Th1_APD, Th1_RPD, Th1_TGB, Th1_TBS).

Abstract: A slip ring system for a wind turbine for electrically connecting a first electrical device and a second electrical device, wherein the first electrical device is mounted to a rotor of the wind turbine, and the second electrical device is mounted to a nacelle of the wind turbine, is provided. The slip ring system comprises a slip ring apparatus and a rotational damping apparatus, with which an electrical connection between the first electrical device and the second electrical device can be established. The slip ring apparatus has a rotatable component with a rotatable electrode and a non-rotatable support electrode, wherein the rotatable electrode is electrically connected to the first electrical device, and the support electrode is electrically connected to the second electrical device.

Abstract: A slip ring system for a wind turbine for electrically connecting a first electrical device and a second electrical device, wherein the first electrical device is mounted to a rotor of the wind turbine, and the second electrical device is mounted to a nacelle of the wind turbine, is provided. The slip ring system comprises a slip ring apparatus and a rotational damping apparatus, with which an electrical connection between the first electrical device and the second electrical device can be established. The slip ring apparatus has a rotatable component with a rotatable electrode and a non-rotatable support electrode, wherein the rotatable electrode is electrically connected to the first electrical device, and the support electrode is electrically connected to the second electrical device.

Abstract: Systems and methods for increasing the power output of wind turbines in a wind farm are disclosed. In particular, a wind farm can include first and second doubly fed induction generator wind turbine systems. The rotational rotor speed of the first wind turbine system can be regulated at reduced wind speeds based at least in part on data indicative of rotor voltage to increase power output of a doubly fed induction generator. The rotor speed can be regulated such that the rotor voltage does not exceed a voltage threshold. The power output of the first wind turbine system can be further increased by reducing its reactive power output. The reduced reactive power output of the first wind turbine system can be compensated for by an increased reactive power output of the second wind turbine system.

Abstract: Systems and methods for increasing the power output of wind turbines in a wind farm are disclosed. In particular, a wind farm can include first and second doubly fed induction generator wind turbine systems. The rotational rotor speed of the first wind turbine system can be regulated at reduced wind speeds based at least in part on data indicative of rotor voltage to increase power output of a doubly fed induction generator. The rotor speed can be regulated such that the rotor voltage does not exceed a voltage threshold. The power output of the first wind turbine system can be further increased by reducing its reactive power output. The reduced reactive power output of the first wind turbine system can be compensated for by an increased reactive power output of the second wind turbine system.

Abstract: Systems and methods for increasing the power output of wind turbines in a wind farm are disclosed. In particular, a wind farm can include first and second doubly fed induction generator wind turbine systems. The rotational rotor speed of the first wind turbine system can be regulated at reduced wind speeds based at least in part on data indicative of rotor voltage to increase power output of a doubly fed induction generator. The rotor speed can be regulated such that the rotor voltage does not exceed a voltage threshold. The power output of the first wind turbine system can be further increased by reducing its reactive power output. The reduced reactive power output of the first wind turbine system can be compensated for by an increased reactive power output of the second wind turbine system.

Abstract: Systems and methods for increasing the power output of wind turbines in a wind farm are disclosed. In particular, a wind farm can include first and second doubly fed induction generator wind turbine systems. The rotational rotor speed of the first wind turbine system can be regulated at reduced wind speeds based at least in part on data indicative of rotor voltage to increase power output of a doubly fed induction generator. The rotor speed can be regulated such that the rotor voltage does not exceed a voltage threshold. The power output of the first wind turbine system can be further increased by reducing its reactive power output. The reduced reactive power output of the first wind turbine system can be compensated for by an increased reactive power output of the second wind turbine system.

Abstract: A method for scheduling the replacement of wind turbine batteries is disclosed. The method may include monitoring an air temperature of a location at which a battery is stored within a wind turbine, determining with a controller a predicted lifetime for the battery based on the air temperature and determining when to replace the battery based at least in part on the predicted lifetime.

Abstract: Tower sections for towers of wind turbines and methods for installing towers of wind turbines are disclosed. A tower includes a preassembled power module having a first cross-sectional area. The tower section includes a wall having an inner surface and an outer surface. The inner surface defines a tower interior and has a first diameter. The tower section further includes a tower flange extending from the wall into the tower interior and having a second diameter less than the first diameter. Further, the tower section includes a platform assembly affixed to the wall and having a third diameter greater than the second diameter. The platform assembly defines an aperture having a second cross-sectional area greater than the first cross-sectional area.

Abstract: A method for scheduling the replacement of wind turbine batteries is disclosed. The method may include monitoring an air temperature of a location at which a battery is stored within a wind turbine, determining with a controller a predicted lifetime for the battery based on the air temperature and determining when to replace the battery based at least in part on the predicted lifetime.

Abstract: Tower sections for towers of wind turbines and methods for installing towers of wind turbines are disclosed. A tower includes a preassembled power module having a first cross-sectional area. The tower section includes a wall having an inner surface and an outer surface. The inner surface defines a tower interior and has a first diameter. The tower section further includes a tower flange extending from the wall into the tower interior and having a second diameter less than the first diameter. Further, the tower section includes a platform assembly affixed to the wall and having a third diameter greater than the second diameter. The platform assembly defines an aperture having a second cross-sectional area greater than the first cross-sectional area.

Abstract: Systems and methods for determining thrust on a wind turbine are disclosed. In one aspect, a system is described that can be comprised of a wind turbine comprising a rotor, wherein one or more rotor blades of the wind turbine are affixed to the rotor; and one or more sensors located on or within the rotor, wherein the one or more sensors measure deflection of the rotor. In one aspect, the measured deflection is correlated with thrust on the wind turbine and the measured thrust can be used to determine at least in part a pitch angle for at least one of the one or more rotor blades during peak shaving.

Abstract: A protection and control system for an electric power system includes at least one electric power generation device and at least one voltage measurement device. The system also includes at least one memory device coupled to the voltage measurement device. The memory device is configured to store a plurality of voltage measurements of the electric power system. The system further includes at least one processor coupled in communication with the memory device. The processor is programmed to determine a change of voltage induced by an electric power generation device, and, determine an approximate location of an electrical fault as a function of the change of voltage induced by the electric power generation device.

Abstract: A method of operating a wind power plant during grid loss is disclosed. The method includes powering a blade pitch drive of the wind power plant by an energy storing unit, and adjusting the pitch of the rotor blades of the wind power plant by means of the blade pitch drive, wherein a rotor shaft keeps rotating and the wind power plant enters a self-sustaining power generating mode upon adjustment of the pitch of the blades.

Abstract: A method for controlling operation of a wind turbine is described. The wind turbine includes a rotor having a plurality of rotor blades. The method includes measuring an atmospheric condition associated with the environment surrounding the wind turbine, providing the measured atmospheric condition to a processor, and determining at least one monitor set point limit based at least partially on the measured atmospheric condition. The method also includes applying the at least one monitor set point limit to wind turbine operation.

Abstract: The disclosure concerns a method for operating a wind turbine having an electrical system, the electrical system comprises a permanent magnet generator having a rotor and a stator, and a power electronic device electrically connected to the permanent magnet generator, wherein the power electronic device and a circuit breaker are electrically disposed in series between the permanent magnet generator and a grid, wherein the permanent magnet generator has permanent magnets and a generator winding into which a voltage is induced by the permanent magnets when the rotor is rotating, the method comprising: generating a signal for tripping the circuit breaker based on a field modification that is modifying the field of the permanent magnets of the permanent magnet generator. Further, the disclosure concerns a method for determining the temperature of at least one permanent magnet of a permanent magnet machine and a controller for a wind turbine.

Abstract: A method of operating a wind power plant during grid loss is disclosed. The method includes powering a blade pitch drive of the wind power plant by an energy storing unit, and adjusting the pitch of the rotor blades of the wind power plant by means of the blade pitch drive, wherein a rotor shaft keeps rotating and the wind power plant enters a self-sustaining power generating mode upon adjustment of the pitch of the blades.

Abstract: The disclosure concerns a wind power plant and its operation during grid loss, wherein the wind power plant comprises a plurality of rotor blades, a blade pitch drive, a rotor shaft, an electric generator, and a control unit for controlling the operations of the wind power plant, wherein the plurality of rotor blades are rotatably connected to the rotor shaft, such that the pitch of the rotor blades can be adjusted by the blade pitch drive under the control of the control unit, and wherein the rotor shaft is operatively connected to the electric generator for generating electric energy, the wind power plant further comprising an energy storing unit for powering the blade pitch drive, wherein the control unit comprises a control module for adjusting the rotor blades and for entering a self-sustaining mode of operation of the wind power plant.

Abstract: A yaw drive system for a wind energy system includes a hydraulic yaw motor for adjusting the yaw angle of a nacelle of a wind energy system, at least one hydraulic pump adapted for providing a pressurized hydraulic fluid, a hydraulic line system, including at least one line connecting the at least one hydraulic pump and the at least one hydraulic yaw motor, and at least one overpressure valve. The at least one overpressure valve is connected to at least one flow path of the hydraulic fluid between the at least one hydraulic pump and the at least one hydraulic motor. Further, a method for changing a yaw angle of a wind turbine nacelle is provided.

Abstract: The disclosure concerns a method for operating a wind turbine having an electrical system, the electrical system comprises a permanent magnet generator having a rotor and a stator, and a power electronic device electrically connected to the permanent magnet generator, wherein the power electronic device and a circuit breaker are electrically disposed in series between the permanent magnet generator and a grid, wherein the permanent magnet generator has permanent magnets and a generator winding into which a voltage is induced by the permanent magnets when the rotor is rotating, the method comprising: generating a signal for tripping the circuit breaker based on a field modification that is modifying the field of the permanent magnets of the permanent magnet generator. Further, the disclosure concerns a method for determining the temperature of at least one permanent magnet of a permanent magnet machine and a controller for a wind turbine.