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 nacelle fixed atop a tower, a generator and a gearbox housed with the nacelle, and a rotor configured with the nacelle having a rotatable hub with one or more rotor blades. The 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 that may be deployed to a utility grid.
At least some known nacelles include a yaw system for controlling a perspective of the rotor relative to a direction of wind. Such wind turbines also include sensors for sensing a direction of the wind. Thus, the wind turbine controller is configured to adjust the yaw of the wind turbine via the yaw system based on the sensed wind direction.
If the wind turbine controller is offline, however, then there is no way to operate the yaw system. Without the yaw system, the wind turbine may be subjected to increased loads (e.g., asymmetric loads) that result from yaw misalignment which may contribute to significant fatigue cycles on the wind turbine components. As the wind turbine components become worn, the wind turbine becomes less effective.
Thus, there is a need for a new and improved system and method for wind turbine yaw control that addresses the aforementioned issues. More specifically, an autonomous system and method for controlling the yaw of the wind turbine that does not rely of the main controller of the wind turbine would be advantageous.