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 nacelle mounted on the tower, a generator positioned in the nacelle, and one or more rotor blades. The one or more rotor blades convert kinetic energy of wind into mechanical energy using known airfoil principles. A drivetrain transmits the mechanical energy from the rotor blades to the generator. The generator then converts the mechanical energy to electrical energy that may be supplied to a utility grid.
Wind turbines typically include a yaw drive, which adjusts a yaw angle (i.e., the angle of the nacelle relative to the tower) of the wind turbine to properly orient the rotor blades relative to the direction of the wind. In this respect, the yaw drive may include one or more yaw adjustment mechanisms, which rotate the nacelle relative to the tower. Furthermore, the wind turbine includes a yaw drive control system for controlling the operation of the various components of the yaw drive, such as the yaw adjustment mechanisms.
During maintenance operations, various components of the yaw drive control system (e.g., power supplies, controllers, sensors, etc.) may be disabled, removed from the wind turbine, or otherwise non-operational. When this occurs, the yaw angle of the wind turbine cannot be adjusted. During certain maintenance activities, it may be necessary to move maintenance equipment, such as cranes, relative to the nacelle. The movement of such equipment increases the duration and the cost of the maintenance operation. Furthermore, an inability to adjust the yaw angle of the wind turbine may result in undesirable aerodynamic loading on nacelle and/or rotor.
Accordingly, a system for controlling a yaw drive of a wind turbine when a native yaw drive control system is non-operational would be welcomed in the art.