Device and method for protecting a wind generator in the event of violent winds and wind generator provided with such a device

A device for protecting a wind generator (1) in the event of violent winds, characterized in that it comprises a connecting part (5) of a blade (6) of a wind generator (1) to the hub (4) of said wind generator (1) comprising one or several blade(s) (6) and as many connecting parts (5) as blades (6), both ends (5.1-5.2) of said connecting part (5), one connected to the hub (4) and the other connected to the blade (6), are characterized by the fact that their respective central axis (B1-B2) forms a non-zero angle (α) with respect to each (B1) other (B2), the connecting part (5) is adapted to be connected to the hub (4) via a drive mechanism such that said connecting part (5) can rotate around the central axis (B1) of its end (5.1) connected to said hub (4), the operation of this drive mechanism causes the tilting according to an angle (β) of the blade (6) which is adapted to be connected to the other end (5.2) of the connecting part (5) via a variable pitch setting mechanism, when said blade (6) is tilted, it is inclined according to said angle (β) in the direction of the nacelle (3), in the safety position (6.2) or conversely in the operating position (6.1), the connecting part (5) is adapted to be blocked by rigidly coupling with the hub (4) by blocking elements (25), the power transmission system of said wind generator (1) is also adapted to be rigidly blocked by blocking elements (14) which block the rotation of the rotor, therefore the operations being performed on all connecting parts (5), the blades (6) inclined in the direction of the nacelle (3), the connecting parts (5) rigidly blocked to the hub (4) and the blocked rotation of the rotor form the protection position of said wind generator (1), remotely controllable in the event of violent winds, wherein said two ends (5.1-5.2) of the connecting part (5) are circular connecting flanges connected by a hollow tube, the walls of which facing said ends (5.1-5.2) are partially removed and connected by reinforcing bars (28), said end (5.1) of the connecting part (5) connected to the hub (4) is at a distance (b) from the central axis (B2) of the other end (5.2) of said connecting part (5) connected to the blade (6), said other end (5.2) of the connecting part (5) connected to the blade (6) is at a distance (a) from the central axis (B1) of the end (5.1) of said connecting part (5) connected to the hub (4), said connecting parts (5) are connected to the hub (4) at equal distances from each other in the case of said rotor comprising several blades (6), and in the circumferential direction of said hub (4), the central axis (B1) of the end (5.1) of said connecting part (5) connected to said hub (4) extends in a radial direction with respect to the rotation axis (A) of said hub.

A method for protecting a wind generator (1) in the event of violent winds, characterized in that it comprises the phases consisting in:

• selecting and sizing the parts, systems, processes, mechanisms, circuits, interfaces of the device for protecting the wind generator (1);
• taking into account, in the conceptual arrangements of the wind generator (1), the impact of the features of the device for protecting the wind generator (1), as well as the loads and load cases induced by the installation and operation of the device for protecting the wind generator (1) on the wind generator (1);
• obtaining the weather information relating to the formation and the movement of violent wind phenomena from a specialized regional meteorological centre;
• when the probability of occurrence of a violent wind event is proved, taking the decision to operate the device for protecting the wind generator (1) such that the wind speed on the site where the wind generator (1) is installed is within the range of that allowing to operate the device for protecting the wind generator (1);
• wherein all operations relating to the operation of the device for protecting the wind generator (1) as shown below are automatically and remotely performed from the wind generator operation centre (31) by sending, by selected communication means, a command for placing in protection position (30.1) or placing in operating state position (30.2) or for starting the wind generator (30.3), to the control-command device (30) of the wind generator (1) pre-programmed to that end, and characterized by the next sequence presented herein, which relates to a wind generator (1) comprising 3 blades (6) connected to three connecting parts (5), respectively, connected at equal distances from each other to the hub (4), in the circumferential direction of said hub (4), and is to be adapted according to the number of blades (6) of the wind generator (1);
• wherein from the operating state position of the wind generator (1), characterized by the operating position (6.1) of the blades (6), the connecting parts (5) rigidly coupled to the hub (4) and the unblocked rotation of the rotor, the sequence of automatic operations for placing in the protection position said wind generator (1) comprises the phases consisting in:
• stopping the rotor, the central axis of the end (5.1) connected to the hub (4) of one of the 3 connecting parts (5) is in the 6 o'clock position with respect to the rotation axis (A) of the hub;
• placing in feathered position the blades (6) of the wind generator (1);
• blocking the rotor by operating the blocking elements (14) of the power transmission system of the wind generator (1);
• unblocking the blocking elements (25) which block the connecting part (5) to the hub (4), both connecting parts (5), the central axis (B1) of the end (5.1) of which, connected to the hub (4), is in the 10 o'clock position for one and the 2 o'clock position for the other with respect to the rotation axis (A) of the hub;
• operating the drive mechanism of both connecting parts (5), the central axis (B1) of the end (5.1) connected to the hub (4) of which is in the 10 o'clock position for one and the 2 o'clock position for the other with respect to the rotation axis (A) of the hub, the pitch setting of the two blades (6) which are connected to these two connecting parts (5) is active so as to promote the rotation of the drive mechanism, the operation of the drive mechanism causes these two connecting parts (5) to rotate around the central axis (B1) of their end (5.1) connected to the hub (4), which causes the blades (6) which are connected to the other end (5.2) of these two connecting parts (5) to tilt, once tilted according to an angle (β) with respect to their operating position (6.1), the two blades (6) are inclined in the direction of the nacelle (3) and of the support tower (2) of the wind generator (1), in their safety position (6.2), the variable pitch setting mechanism of these two blades (6) is active so as to limit the loads acting thereon;
• blocking the blocking elements (25), which block the connecting part (5) to the hub (4), both connecting parts (5), the central axis (B1) of the end (5.1) connected to the hub (4) of which is in the 10 o'clock position for one and the 2 o'clock position for the other with respect to the rotation axis (A) of the hub;
• unblocking the rotor by operating the blocking elements (14) of the power transmission system of the wind generator (1);
• rotating the rotor according to a 60° angle with respect to the rotation axis (A) of the hub in the counterclockwise direction, the connecting part (5), the central axis (B1) of the end (5.1) connected to the hub (4) of which was in the 6 o'clock position with respect to the rotation axis (A) of the hub, has its central axis (B1) of the end (5.1) connected to the hub (4) in the 4 o'clock position with respect to the rotation axis (A) of the hub;
• blocking the rotor by operating the blocking elements (14) of the power transmission system of the wind generator (1);
• unblocking the blocking elements (25), which block the connecting part (5) to the hub (4), the connecting part (5), the central axis (B1) of the end (5.1) connected to the hub (4) of which is in the 4 o'clock position with respect to the rotation axis (A) of the hub;
• operating the drive mechanism of the connecting part (5), the central axis (B1) of the end (5.1) connected to the hub (4) of which is in the 4 o'clock position with respect to the rotation axis (A) of the hub, the pitch setting of the blade (6) which is connected to this connecting part (5) is active so as to enhance the rotation of the drive mechanism, the operation of the drive mechanism causes this connecting part (5) to rotate around the central axis (B1) of its end (5.1) connected to the hub (4), which causes the blade (6) which is connected to the other end (5.2) of this connecting part (5) to tilt, once tilted according to an angle (β) with respect to their operating position (6.1), the blade (6) is inclined in the direction of the nacelle (3) and of the support tower (2) of the wind generator (1), in its safety position (6.2), the variable pitch setting mechanism of this blade (6) is active so as to limit the loads acting thereon;
• blocking the blocking elements (25) which block the connecting part (5) to the hub (4), the connecting part (5), the central axis (B1) of the end (5.1) connected to the hub (4) of which is in the 4 o'clock position with respect to the rotation axis (A) of the hub;
• electrically supplying said wind generator (1) by the autonomous and independent electrical source of the electrical network provided in case of a power cut thereof;
• wherein the thus-formed position is the position for protecting the wind generator in the event of violent winds of the present invention, wherein said protection position is characterized by the blades (6) in the safety position (6.2), the connecting parts (5) rigidly blocked to the hub (4) and the blocked rotation of the rotor, wherein during this operation and in this position, the orientation mechanism (17) of the nacelle (3) with respect to the wind direction is active;
• after the violent wind event has dissipated and the probability of occurrence of this risk is definitely ruled out by the specialized regional meteorological centre, the command (30.2) for placing the wind generator (1) back in its operating state is remotely transmitted to the control-command system (30) of the wind generator (1), which triggers thereby the sequence opposite to that previously-described such that the connecting parts (5) are blocked to the hub (4) in the operating position (6.1) of the blades (6) and that the power transmission system of said wind generator (1) is unblocked;
• when said wind generator is in its operating state position, an automatic self-control sequence (30.6) of the functions of the wind generator (1) is operated by the control-command device (30) of said wind generator (1) and gives rise to a report (30.7) transmitted to the operation centre (31) of said wind generator (1), if the transmitted report (30.7) is positive, said wind generator (1) is re-operated by the corresponding remote control (30.3) of the control-command device (30) of the wind generator (1), if said wind generator (1) is damaged, the required measures are taken by the operation centre (31) of the wind generator (1).