FIELD

The present disclosure relates in general to wind turbines, and more particularly to systems and methods for controlling wind turbines in the presence of solar heating.

BACKGROUND

Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The nacelle includes a rotor assembly coupled to the gearbox and to the generator. The rotor assembly and the gearbox are mounted on a bedplate support frame located within the nacelle. The one or more rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy and the electrical energy may be transmitted to a converter and/or a transformer housed within the tower and subsequently deployed to a utility grid. Modern wind power generation systems typically take the form of a wind farm having multiple such wind turbine generators that are operable to supply power to a transmission system providing power to an electrical grid.

In certain instances, the capturing of the kinetic energy of the wind by the rotor blades may result in a displacement of the nacelle from a neutral position. As operational controls of the wind turbines become more sensitive, the displacement of the nacelle may be employed in the generation of various setpoint commands. Accordingly, in order to accurately control the wind turbine, it may be desirable to differentiate a nacelle displacement resulting from an operation of the wind turbine from a nacelle displacement resulting from other factors.

Thus, the art is continuously seeking new and improved systems and methods that address the aforementioned issues relating to the displacement of the nacelle. As such, the present disclosure is directed to systems and methods for controlling a wind turbine in the presence of solar heating.

BRIEF DESCRIPTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In one aspect, the present disclosure is directed to a method for controlling a wind turbine. The wind turbine may have a nacelle mounted atop the tower. The method may include determining, via a controller, a thermal gradient of the tower due to solar heating for a given sun position. The controller may then determine a displacement of a reference point of the wind turbine from a nominal position resulting from a thermal expansion of a portion of the tower. The displacement may include a displacement magnitude and a displacement direction, and the displacement direction may be in a radial direction opposite a location of a maximal peak of the thermal gradient on the tower. The method may also include determining, via the controller, a correction factor corresponding to the displacement, wherein the correction factor is configured to mitigate an impact of the displacement resulting from the thermal expansion of the portion of the tower. Additionally, the method may include generating, via the controller, a setpoint for a component of the wind turbine based, at least in part, on the correction factor. Further, the method may include establishing an operating state of the wind turbine based, at least in part, on the setpoint.

In another aspect, the present disclosure is directed to a method for controlling a plurality of wind turbines of a wind farm. The plurality of wind turbines may include a designated turbine having a nacelle mounted atop a tower. The method may include determining, via a controller, a thermal gradient of the tower of the designated turbine due to solar heating for a given sun position. The controller may also determine a displacement of a reference point of the designated turbine from a nominal position resulting from a thermal expansion of a portion of the tower. The displacement may include a displacement magnitude and a displacement direction, with the displacement direction being in a radial direction opposite a location of a maximal peak of the thermal gradient on the tower. The controller may also determine a correction factor corresponding to the displacement. The correction factor may be configured to mitigate an impact of the displacement resulting from the thermal expansion of the portion of the tower. The method may also include implementing, via the controller, the correction factor at each additional wind turbine of the plurality of wind turbines and determining, via the controller, a setpoint for a component of each wind turbine of the plurality of wind turbines based, at least in part, on the correction factor. Additionally, the method may include establishing an operating state of each wind turbine of the plurality of wind turbines based, at least in part, on the setpoint.

In another aspect, the present disclosure is directed to a system for controlling a wind turbine. The system may include a tower having a plurality of vertically arranged tower segments and a nacelle mounted atop the tower. Additionally, the system may include a controller. The controller may include at least one processor configured to perform a plurality of operations. The plurality of operations may include any of the operations and/or features described herein.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

