LOCKING SYSTEM FOR A ROTATABLE MOUNTED UNIT OF A WIND TURBINE, WIND TURBINE AND METHOD FOR OPERATING A LOCKING SYSTEM

Abstract

A locking system for a rotatable mounted unit of a wind turbine is provided, including at least one lock adapted to lock and unlock the rotatable mounted unit, wherein the locking system includes first and second devices to prevent rotation, wherein the lock is prevented from changing from the locked state if at least one of the devices to prevent rotation is in a secure state, wherein a control unit is adapted to generate a control command changing the first device to prevent rotation into the secure state if the lock currently locks the rotatable mounted unit, wherein the locking system automatically changes the second device to prevent rotation into the secure state if an access condition is fulfilled, wherein the access condition is fulfilled if a recorded access information indicates that a room with the rotatable mounted unit is currently accessed or going to be accessed.

Claims

1. A locking system for a rotatable mounted unit of a wind turbine, comprising at least one lock configured to lock and unlock the rotatable mounted unit wherein the locking system comprises a first device to prevent rotation and a second device to prevent rotation, wherein the lock is prevented from changing from the locked state into the unlocked state if at least one of the devices to prevent rotation is in a secure state, wherein a control unit is configured to generate a control command changing the first device to prevent rotation into the secure state if the lock currently locks the rotatable mounted unit, wherein the locking system is configured to automatically change the second device to prevent rotation into the secure state if an access condition is fulfilled, wherein the access condition is fulfilled if a recorded access information indicates that a room with the rotatable mounted unit is currently accessed or going to be accessed via an entrance.

2. The locking system according to claim 1 wherein the device to prevent rotation includes switches configured to disconnect the power supply of at least one actuator of the lock.

3. The locking system according to claim 2, wherein the at least one actuator is a valve of a hydraulic drive of the lock or an electric motor.

4. The locking system according to claim 1, wherein at least one key station for storing a key to lock and unlock at least one entrance for the room is provided, wherein the access information depends on whether the key currently stored in or at the key station, wherein the access condition is fulfilled if the key is removed from the key station.

5. The locking system according to claim 4, wherein the key station comprises a key receiver configured to hold or carry the key when the key is stored in or at the key station.

6. The locking system according to claim 5, wherein the key receiver is or comprises a key hole where the key is to be inserted for storage, wherein, for storing the key, the key is inserted into the key hole and turned and, for removing the key, the key is turned back before it can be pulled out, wherein turning the key back before removing the key changes the second device to prevent rotation into the secure state or leaves the second device to prevent rotation in the secure state.

7. The locking system according to claim 4, wherein a further control unit is configured to generate a control command changing the second device to prevent rotation into the secure state when the key is removed from the key station or in that the key station is coupled with the second prevent device to prevent rotation by a coupling mechanism configured to change the second device to prevent rotation into the secure state when the key is removed from the key station.

8. The locking system according to claim 4, wherein at least two key stations, each storing a key, are provided, wherein the locking system is configured to automatically change the second device to prevent rotation into the secure state if the key from at least one of the key stations is removed.

9. The locking system according to claim 4, wherein the control unit or a further control unit is configured to generate a control command changing the at least one key station into a state generally allowing the removal of the key from the key station, if the lock currently lock the rotatable mounted unit.

10. The locking system according to claim 1, wherein the control unit is configured to generate a control command allowing the first device to prevent rotation to leave the secure state only if the at least one entrance is closed and/or if the access condition is fulfilled, in particular if the or all of the key stations store its respective key.

11. The locking system according to claim 1, wherein at least one pad-lock provided, wherein the pad-lock can be attached to the at least one entrance to mark and/or prevent the entrance being closed.

12. The locking system according to claim 1, wherein at least one pin or latch of the lock engages into at least one recess or hole of the rotatable mounted unit for locking the rotatable mounted unit.

13. A wind turbine comprising at least one rotatable mounted unit, at least one entrance leading to a room with the rotatable mounted unit and a locking system according to claim 1.

14. A method for operating a locking system for a rotatable mounted unit of a wind turbine, comprising at least one locking configured to lock and unlock the rotatable mounted unit, wherein a first device to prevent and a second device to prevent rotation are used, wherein the lock is prevented from changing from the locked state into the unlocked state if at least one of the devices to prevent rotation is in a secure state, wherein the first to prevent rotation is changed into the secure state if the lock currently locks the rotatable mounted unit, wherein the second device to prevent rotation automatically change into the secure state if an access condition is fulfilled, wherein the access condition is fulfilled if a recorded access information indicates that a room with the rotatable mounted unit is currently accessed or going to be accessed via an entrance.

15. A locking system for a rotatable mounted unit of a wind turbine, comprising at least one locking means configured to lock and unlock the rotatable mounted unit, wherein the locking system comprises a first prevention means and a second prevention means, wherein the locking means is prevented from changing from the locked state into the unlocked state if at least one of the prevention means is in a secure state, wherein a control unit is configured to generate a control command changing the first prevention means into the secure state if the locking means currently lock the rotatable mounted unit, wherein the locking system is configured to automatically change the second prevention means into the secure state if an access condition is fulfilled, wherein the access condition is fulfilled if a recorded access information indicates that a room with the rotatable mounted unit is currently accessed or going to be accessed via an entrance means.

Description

DETAILED DESCRIPTION

[0039] FIG. 1 depicts a wind turbine 1 with a locking system 2, wherein details of the locking system 2 are shown in FIG. 2. The wind turbine 1 comprises several rotatable mounted units 3, namely a hub 4 with blades 5 and a main shaft 6 which connects the hub 4 with a generator 8 via a bearing system 7 to convert the rotational energy of the hub 4 into electrical energy. The main shaft 6, the bearing system 7 and the generator 8 are located within a room 9 of a nacelle 10, which is located on top of a tower 11 of the wind turbine 1.

[0040] The room 9 with the rotatable mounted units 3 can be accessed, e.g., by a technician 12 to perform maintenance work on the rotatable mounted units 3, via an entrance means or entrance 13, namely a door 14 leading from a section 15 of the nacelle 10 without a rotatable mounted units 3 into the room 9. The entrance means 13 can also be a hatch or the like.

[0041] If maintenance work has to be performed on or in the vicinity of the rotatable mounted units 3, i.e., within the room 9, the rotatable mounted units 3 have to be locked. Otherwise, the technician 12 could be in serious danger if the rotatable mounted units 3 start to rotate unexpectedly. Hence, a locking means or lock 16 is provided to lock and unlock the rotatable mounted units 3, in particular the hub 4. The locking means 16 comprises a pin 17 which engages into a rotating part of the wind turbine 1, in particular into a hole 18 of the hub 4 or a flange of the hub 4 in a locked state. To change the locking means 16 from the locked state, where it locks the rotatable mounted unit 3, into an unlocked state, where it does not lock the rotatable mounted unit 3, the pin 17 can be moved along its longitudinal pin axis out of the hole 18 via a hydraulic drive 19 which comprises a cylinder 20 and valves 21. Alternatively, the locking means 16 can be driven by an electric motor (not shown).

[0042] The locking system 2 comprises a first prevention means or first device to prevent rotation 22 and a second prevention means or second device to prevent rotation 23. The prevention means 22, 23 are electrical switches 24 to connect and disconnect the power supply 25 of actuators 26 of the locking means 16, i.e., of the valves 21. If one of the prevention means or devices 22, 23 is in a secure state, the respective switch 24 is open and the power supply 25 of the actuator 26 is interrupted. As a consequence, the locking means 16 cannot change its current state, in particular it cannot change from the locked state into the unlocked state.

[0043] A control unit 27 is adapted to generate a control command changing the first prevention means 22 into the secure state if the locking means 16 currently locks the rotating part, in particular the hub 4. As a consequence, the locking means 16 is prevented from changing into the unlocked state unintentionally. As a result, a first protection layer is realized preventing the rotatable mounted unit 3 from rotating while maintenance work is performed in the room 9. To sense the current state of the pin 17, the control unit 27 is connected with sensors 28, 29. The sensor 28 is used to sense if the locking means 16 is in the unlocked state. To avoid wrong detections indicating erroneously that the locking means 16 is in the locked state, two sensors 29 are used to detect this state. To allow the first prevention means 22 to leave the secure state, the control unit 27 is adapted to generate a respective control command.

[0044] To realize a second protection layer preventing the rotatable mounted unit 3 from rotating, the locking system 2 is adapted to automatically change the second prevention means 23 into the secure state if an access condition is fulfilled. The access condition is fulfilled, if an access information indicates that the room 9 is currently accessed or going to be accessed via the entrance means 13. Hence, even if the first prevention means 22 leaves the secure state erroneously, the open switches 24 of the second prevention means 23 prevent the locking means 16 to change into the unlocked state.

[0045] For instance, five key stations 30 are provided for storing a key 31 each. Alternatively, the locking system 2 can comprise only one key station 30 adapted to store several keys 31. The keys 31 are adapted to lock and unlock the door 14 and/or other entrance means 13 leading into the room 9. Although the keys 31 are classic keys, the keys can also be key cards, security tokens, in particular with an RFID-transponder, or the like. The access information is fulfilled if at least one of the keys 31 is removed from its respective key station 30.

[0046] Each entrance means 13 comprises and/or is dedicated to one of five key boxes 32 to lock and unlock a dedicated entrance means 13. In FIG. 2, the key 31 of one key station 30 has been removed. As a consequence, also the second prevention means 23 has been changed into the secure state. The respective key 31 has been used at the key box 32 to unlock the door 14, which is the entrance means 13 which is dedicated to the key box 32.

[0047] It is only possible to unlock the door 14 and, hence, to get access into the room 9 after the respective key 31 has been removed from the key station 30 and inserted in the key box 32. The second protection layer is based on the idea that this removing of the key 31 from the key station 30 causes the change of the second prevention means 23 into the secure state. As a consequence, it is not possible to get access into the room 9 while the second prevention means 23 is not in the secure state and, thus, while the rotatable mounted units 3 are not locked.

[0048] In other words, the only possibility to get access into the room 9, namely by removing the key 31 from the key station 30, causes an automatic change of the second prevention means 23 into the secure state. Furthermore, it is only possible to leave the second prevention means 23 from the secure state, after the key 31 is back again at its key station 30, which is only possible after the door 14 has been locked again.

[0049] Next, the key stations 30 will be described in more detail. Each of the key stations 30 comprises a key receiver 33, namely a keyhole. To store the key 31 at the key station 30, the key is plugged into the respective key receiver 33. After this, the key 31 can be turned, e.g., around an angle of 90°, until the head of the key 31 is exemplarily into a vertical position. In this position, the key 31 cannot be removed from the key receiver 33. To remove the key 31, the key has to be turned back, e.g., around −90°, before it can be pulled out.

[0050] Assuming that all keys 31 are currently stored in the respective key stations 30, if one of the keys 31 is turned in order to remove it, the second prevention means 23 automatically changes into the secure state. After this, further keys 31 can be removed from the key stations 30 which does not lead to a change of the secure state of the second prevention means 23. To leave the secure state of the second prevention means 23, all keys 31 have to be stored again in the key stations 30. In other words, only if the last of the missing keys 31 has been brought back to the key stations 30, the turning of this key 31 automatically closes the switches 24 of the second prevention means 23.

[0051] To change the current state of the second prevention means 23 when the key 31 is removed from or brought back to the key station 30, a, regarding the control unit 27, further control unit (not shown) is adapted to generate a respective control command. Alternatively, the control unit 27 can be adapted to generate this control command. In an embodiment, however, a mechanical coupling mechanism adapted to automatically change the second prevention means 23 into or leave it from the secure state when the key 31 is turned, is provided.

[0052] The control unit 27 is adapted to generate a control command changing the key stations 30 into a state generally allowing the removal of the keys 31, if the locking means 16 currently locks the rotatable mounted unit 3. Hence, if the rotatable mounted unit 3 is currently not locked, it is not possible to remove the keys 31 from the key stations 30. If the key stations 30 are in this state, signal lights 34 of the key stations 30 are green. Otherwise, the signal lights 34 are red or off.

[0053] Furthermore, the control unit 27 is adapted to generate a control command allowing the first prevention means 22 to leave the secure state only if all entrance means 13 are closed and locked. This control command can also be generated if the access condition is not fulfilled, i.e., if none of the keys 31 is removed from the key station 30. To detect whether the entrance means 13 are closed or locked, the control unit 27 is connected with the key boxes 32 and/or sensors (not shown) which are provided in the vicinity of the entrance means 13.

[0054] The locking system 2 comprises at least one pad-lock 35. If several technicians 12 are present at the wind turbine 1, each technician 12 has his own pad-lock 35. When entering the room 9, the respective technician 12 attaches his pad-lock 35 to the respective entrance means 13. This marks the door 14 to indicate that somebody is currently inside the room 9 and prevents the door 14 from being closed. The number of pad-locks 35 attached to the entrance means 13 indicates the number of technicians 12 who are currently within the room 9.

[0055] As shown in FIGS. 1 and 2, the technician 12 is currently working within the room 9 and has marked the door 14 with the pad-lock 35. Hence, it can be seen from the section 15 that somebody is currently inside of the room 9. Additionally, the pad-lock 35 physically prevents the door 14 from being closed and locked and, since the key 31 can only be removed from the key box 32 if the door is closed, the key 31 is prevented from being brought back to the key station 30. As a consequence, the second prevention means 23 cannot leave the secure state if the pad-lock 35 is attached to the door 14 and the technician 12 is inside the room 9.

[0056] In the following, details according to the method according to embodiments of the present invention are described on the basis of the FIGS. 1 and 2. To lock or engage the rotatable mounted units 3, the hub 4 has to be brought into a position where the pin 17 can engage into the hole 18. A turbine controller or, alternatively, the control unit 27 changes the locking means 16 into the locked state by activating the hydraulic drive 19. This can be triggered by the technician 12 via a control device (not shown) of the wind turbine 1. Alternatively, a respective signal can be generated from remote. After the locking means 16 has reached the locked state, the sensors 29 give a respective signal to the control unit 27.

[0057] Next, the control unit 27 generates the control command changing the first prevention means 22 into the secure state.

[0058] To open the switches 24 of the first prevention means 22, the control unit 27 generates a control command. Another control command generated by the control unit 27 changes the key station 30 into a state generally allowing it to remove the key 31. In addition, the signal light 34 turns from red or from the off-state into green colour. Next, one of the keys 31 is removed from the key station 30, e.g., by the technician 12, wherein the second prevention means 23 automatically changes into the secure state by opening the respective switches 24. The removed key 31 can now be inserted into the key box 32 of the entrance means 13 to unlock the entrance means 13. Next, the pad-lock 35 is attached to the door 14.

[0059] To unlock or retract the rotatable mounted units 3, all pad-locks 35 have to be removed from the entrance means 13 after all technicians 12 have left the room 9. Next, the entrance means 13 are locked by the keys 31 which are then stored in the respective key stations 30. While the last key 31 is turned into the vertical position, the second prevention means 23 automatically leaves the secure state, i.e., the respective switches 24 are closed. The key stations 30 provide a dual channel signal to the control unit 27 indicating that all entrance means 13 are closed and locked leading the control unit 27 to generate a control command which causes the first prevention means 22 to leave the secure state, i.e., to close the respective switches 24. Next the control unit generates a control command, e.g., to the turbine controller, which changes the locking means 16 into the unlocked state. After the locking means 16 has reached the unlocked state, the sensor 28 gives a respective signal to the control unit 27.

[0060] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0061] For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.