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, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy from wind using known foil principles and transmit the kinetic energy through rotational energy 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.
The uptower components of the wind turbines require periodic maintenance, inspection, and repair, and the safety of personnel conducting such procedures is paramount. The rotating components of the rotor, drivetrain, and yaw system all present risks to personnel, and it is an important safety consideration to prevent the rotation of such components while personnel are performing certain procedures in the nacelle or rotor hub. In various jurisdictions around the world, permits for installation and operation of wind turbines require interlocks between the rotor and yaw systems with the hatches in the nacelle that give access to the respective components/systems.
In this regard, U.S. Patent Publication No. 2010/0232978 describes a locking arrangement for locking a hub of a wind turbine against rotational movements relative to a base frame of the nacelle of the wind turbine. Such a locking arrangement is, e.g., required for safety purposes in order to prevent the hub from rotating during maintenance of the wind turbine. The locking arrangement may include a safety system that prevents access to an interior part of the hub when certain components of the locking arrangement are in the release position. The safety system may, e.g., be coupled to a locking system of a hatch or a door arranged across an opening creating access to the hub, wherein the safety system prevents the locking system from being unlocked if the locking components are in the release position, i.e. if the hub is allowed to rotate relative to the base frame. Thereby it is ensured that maintenance personnel can only gain access to the interior part of the hub if the hub is securely locked to the base frame.
Accordingly, there is an ongoing need for improved safety systems and procedures related to controlling access to areas of the nacelle and rotor hub when rotating components present a risk to personnel.