Device and method for assisting in mounting or dismounting rotor blades

Abstract

There is described a device and a method for mounting or dismounting at least one rotor blade (6) on or from a rotor (4) of a wind turbine (1), the wind turbine (1) comprising: an external power source; a generator (5) of the wind turbine (1), the generator (5) comprising a frequency converter and being mechanically connected to the rotor (4) and electrically connected by the frequency converter to an external power source for supplying power to the generator (5) to rotate the rotor (4); and a control device configured to control the generator (5). The generator (5) is controlled to rotate the rotor (4) to a predetermined position. When the rotor (4) is located at a predetermined position, the blades (6) are attached to or detached from the rotor (4).

Description

Technical Field

[0001] The present invention relates to a device for assisting in mounting at least one rotor blade onto a rotor of a wind turbine or for dismounting from the rotor of a wind turbine, and a method for mounting at least one rotor blade onto a rotor of a wind turbine or for dismounting from the rotor of a wind turbine. Background Art

[0002] During the installation of a wind turbine, during the single blade installation process, each blade is individually installed one by one. During such a single blade installation process, it is necessary to rotate the rotor after installing a blade so that the next blade can be installed in a horizontal position. Rotating an unbalanced rotor and locking the rotor for installation / assembly is a technical challenge.

[0003] In some wind turbines, the rotor is rotated by means of a hydraulic tool. Recently, as the size of the turbine has increased significantly, the capacity of the tool to rotate the rotor must be increased during blade installation. As a result, the size and weight of the hydraulic tool have also increased over time, and more challenges are created in the manipulation and use of the tool during blade installation. On the one hand, the tool takes longer to rotate the rotor during blade installation, and on the other hand, the rotation speed must be increased so that more and more turbines can be installed in less time.

[0004] There may be a need for a device for assisting in mounting at least one rotor blade onto a rotor of a wind turbine or for dismounting from the rotor of a wind turbine, and a method for mounting at least one rotor blade onto a rotor of a wind turbine or for dismounting from the rotor of a wind turbine, which is conducive to mounting the rotor blade onto the rotor. Summary of the Invention

[0005] This need can be met by the subject matter of the independent claims. Advantageous embodiments of the present invention are described by the dependent claims.

[0006] According to a first aspect of the present invention, there is provided a device for assisting in mounting at least one rotor blade onto a rotor of a wind turbine or for dismounting from the rotor of a wind turbine. The device includes: an external power supply; a generator of the wind turbine, the generator including a frequency converter and being mechanically connected to the rotor and electrically connected to the external power supply through the frequency converter for supplying power to the generator to rotate the rotor; and a control device configured to control the generator to rotate the rotor to a predetermined position in which the blade will be mounted onto the rotor or dismounted from the rotor.

[0007] This aspect of the invention is based on the idea that the rotation of the rotor can be achieved in a quick and precise manner without any hydraulic tools.

[0008] According to another embodiment of the invention, the device further comprises: a brake for decelerating the rotor; an encoder for detecting the rotor position and / or the rotor speed; a locking device for locking and unlocking the rotor; at least one sensor for detecting a locking indicator arranged at the rotor, the locking indicator indicating the locked position of the rotor; wherein the control device is configured to: control the generator to rotate the rotor towards a target position when the locking device is in an unlocked state and the brake is in a released state, while the actual rotor position is determined by the encoder; control the generator to stop or decelerate the rotor when the actual rotor position corresponds to the target position of the rotor; control the generator to rotate the rotor towards the locked position, which is the predetermined position; control the brake to hold the rotor together with the generator when the sensor detects the locking indicator, such that the rotor is in the locked position; and control the locking device to lock the rotor when the rotor is in the locked position. In this embodiment, the rotation of the rotor is achieved in two steps, namely, a first step of rotating the rotor quickly close to the target position which can be near the predetermined position, for example, rotating 120°. The control device uses the encoder to monitor the rotor speed and / or position in this first step. The second step is a fine adjustment, in which the control device uses the sensor to align the locking device, for example, aligning the locking hole with the locking pin. The brake usually already exists in a wind turbine.

[0009] According to another embodiment of the invention, the wind turbine comprises a power socket which is configured to connect the generator to the power grid during the operation of the wind turbine, wherein, during the installation or removal of the blade, the power socket is disconnected from the power grid and connected to the power line of an external power source. In this embodiment, the socket already existing in the wind turbine is used.

[0010] According to another embodiment of the invention, the device further comprises at least one circuit breaker which connects and interrupts at least one of the power lines between the external power source and the generator.

[0011] According to another embodiment of the invention, the external power source is an external generator, an external battery arranged on the helicopter platform of the wind turbine, or an external power grid. The external power source can also be a power source in or at the installation vessel, wherein the power is transmitted through a temporary or fixed cable in the tower of the wind turbine to the generator (or converter) in the nacelle of the wind turbine.

[0012] According to another embodiment of the present invention, the locking indicator is a locking hole provided in the rotor, in particular in the brake disc of the brake, and the locking device includes a locking pin provided in the fixed frame of the wind turbine, wherein when the rotor is in the locked position, the locking pin can be inserted into the locking hole to lock the rotor.

[0013] According to another embodiment of the present invention, two sensors are provided at positions diametrically opposite on the diameter of the locking pin, wherein the sensors are configured to respectively detect the circumferential edge of the locking hole. This embodiment uses a simple sensor configuration.

[0014] According to another embodiment of the present invention, the sensor is a camera configured to detect the circumferential edge of the locking hole.

[0015] To unlock the locking device, the control device according to another embodiment is configured to: control the generator to rotate the rotor to a position where the locking pin is out of contact with the circumferential edge of the locking hole, and control the locking device to withdraw the locking pin from the locking hole to unlock the rotor. For example, if two sensors are provided at positions diametrically opposite on the diameter of the locking pin, the control device may be configured to: determine which of the two sensors is closer to the circumferential edge of the locking hole; control the generator to rotate the rotor to a position where the locking pin is out of contact with the circumferential edge of the locking hole; and control the locking device to withdraw the locking pin from the locking hole, thereby unlocking the rotor. In any case, the locking pin can be withdrawn from the locking hole in the unloaded state.

[0016] According to another aspect of the present invention, a method of mounting at least one rotor blade to or removing it from the rotor of a wind turbine is provided. The wind turbine includes an external power source, a generator, and a control device. The generator includes a frequency converter and is mechanically connected to the rotor and electrically connected to the external power source through the frequency converter for supplying power to the generator to rotate the rotor. The control device is configured to control the generator. The method includes the following steps: controlling the generator to rotate the rotor to a predetermined position; and when the rotor is in the predetermined position, mounting the blade to or removing it from the rotor.

[0017] According to another embodiment of the present invention, the wind turbine further comprises: a brake for decelerating the rotor; an encoder for detecting the rotor position and / or the rotor speed; at least one sensor for detecting a locking indicator arranged at the rotor, the locking indicator indicating a locked position of the rotor; and a locking device for locking and unlocking the rotor. The method comprises the steps of: when the locking device is in an unlocked state and the brake is in a released state, controlling the generator to rotate the rotor towards a target position while determining the actual rotor position by the encoder; when the actual rotor position corresponds to the target position of the rotor, controlling the generator to stop or decelerate the rotor; controlling the generator to rotate the rotor towards the locked position, the locked position being the predetermined position; when the sensor detects the locking indicator, controlling the brake to hold the rotor together with the generator such that the rotor is in the locked position; controlling the locking device to lock the rotor; and when the rotor is locked by the locking device, mounting or removing the rotor blades to or from the rotor.

[0018] According to another embodiment of the present invention, the external power source is an external generator or an external battery, which is preferably temporarily arranged on the helicopter platform of the wind turbine, and at least one of the encoder and the at least one sensor is temporarily mounted to the wind turbine; and after mounting or removing the at least one blade, at least one of the external power source, the encoder and the at least one sensor is removed.

[0019] According to another embodiment of the present invention, the wind turbine comprises a plurality of blades, and each blade is mounted to or removed from the rotor substantially in the same longitudinal blade orientation, preferably the horizontal orientation of the blade.

[0020] According to another embodiment of the present invention, wherein the generator is mounted in the nacelle of the wind turbine, and the method further comprises: yawing the nacelle to the mounting or removal position before mounting or removing the blade.

[0021] According to another embodiment of the present invention, the method further comprises at least one of the following steps: the brake includes a brake disc and friction pads operated by a caliper, wherein the caliper keeps the friction pads in continuous contact with the brake disc, even in the released state of the brake; the locking indicator is a locking hole provided in the rotor, and the locking device includes a locking pin provided in a fixed frame of the wind turbine, wherein when the rotor is in the locked position, the locking pin can be inserted into the locking hole to lock the rotor, wherein the locking pin is operated by a hydraulic pump, and the hydraulic pump is activated before inserting the locking pin into the locking hole or withdrawing the locking pin from the locking hole; the locking indicator is a locking hole provided in the rotor, and the locking device includes a locking pin provided in a fixed frame of the wind turbine, wherein when the rotor is in the locked position, the locking pin can be inserted into the locking hole to lock the rotor, wherein a hydraulic accumulator is provided to support and reserve hydraulic fluid for at least one of the locking device and the brake.

[0022] In another embodiment, the actuator of the locking pin can be an electric motor, preferably having gears.

[0023] It must be noted that embodiments of the present invention have been described with reference to different subjects. In particular, some embodiments have been described with reference to method-type claims, while other embodiments have been described with reference to device-type claims. However, those skilled in the art will understand from the above and the following description that, unless otherwise stated, any combination between features related to different subjects, in particular any combination between the features of method-type claims and the features of device-type claims, is also considered to be disclosed with this document, in addition to any combination of features belonging to one type of subject.

[0024] The above and other aspects of the present invention are apparent from the examples of the embodiments described below and are explained with reference to the examples of the embodiments. The present invention will be described in more detail below with reference to the examples of the embodiments, but the present invention is not limited to these embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A wind turbine according to an embodiment is shown;

[0026] Figure 2 The power socket of the generator of a wind turbine according to an embodiment is shown;

[0027] Figure 3 A locking device according to an embodiment is shown;

[0028] Figure 4 A torque diagram during rotation of the rotor according to an embodiment is shown;

[0029] Figure 5Shows a user interface during yawing of the nacelle according to an embodiment;

[0030] Figure 6 Shows a user interface during rotation of the rotor according to an embodiment; and

[0031] Figure 7 Shows a user interface during rotation of the rotor according to an embodiment;

[0032] Figure 8 Shows a user interface during rotation of the rotor according to an embodiment. Detailed Description

[0033] The illustrations in the drawings are schematic. Note that in different figures, similar or identical elements or features are provided with the same reference numerals or reference numerals that differ only in the first digit from the corresponding reference numerals. To avoid unnecessary repetition, elements or features that have been described with reference to the foregoing embodiments will not be described again later in the specification.

[0034] In addition, spatial relative terms, such as "front" and "rear", "above" and "below", "left" and "right", etc., are used to describe the relationship of an element to another or other elements shown in the figure. Thus, the spatial relative terms may apply to an orientation different from the orientation depicted in the figure during use. Obviously, all these spatial relative terms refer only to the orientation shown in the figure for the sake of description and need not be restrictive, since the device according to an embodiment of the present invention may assume an orientation different from the orientation shown in the figure during use.

[0035] Figure 1 Shows a wind turbine 1. The wind turbine 1 includes a nacelle 3 and a tower 2. The nacelle 3 is mounted on top of the tower 2. The nacelle 3 is rotatably mounted relative to the tower 2 by means of a yaw bearing. The axis of rotation of the nacelle 3 relative to the tower 2 is referred to as the yaw axis 9.

[0036] The wind turbine 1 further includes a rotor 4 having three rotor blades 6 (two of the rotor blades 6 are shown in Figure 1 ). Each blade 6 is configured to pitch about the pitch axis of the blade 6 at a pitch angle. The rotor 4 is mounted by means of a main bearing 7 to be rotatable about an axis of rotation 8 (rotor axis) relative to the nacelle 3.

[0037] The wind turbine 1 further includes a generator 5. The generator 5 in turn includes a rotor that connects the generator 5 to the rotor 4. If the rotor 4 is directly connected to the generator 5, the wind turbine 1 is referred to as a gearless direct drive wind turbine. Such a generator 5 is referred to as a direct drive generator 5. As an alternative, the rotor 4 can also be connected to the generator 5 via a gearbox. This type of wind turbine 1 is referred to as a geared wind turbine. The present invention is applicable to both types of wind turbines 1.

[0038] The generator 5 is housed within the nacelle 3. The generator 5 is arranged and configured to convert the rotational energy from the rotor 4 into electrical energy in the form of AC power.

[0039] According to the present invention, there is provided a device for assisting in mounting a blade 6 onto or removing it from the rotor 4 of a wind turbine 1. The device includes an external power source (not shown). The external power source can be an external generator or an external battery, which is preferably arranged on the helicopter platform of the wind turbine 1. The external power source can also be an external power grid, such as the power grid to which the wind turbine 1 is intended to be connected. The device for assisting in mounting a blade 6 onto or removing it from the rotor 4 further includes the generator 5 of the wind turbine 1, wherein the generator 5 includes a frequency converter, and is mechanically connected to the rotor 4 and electrically connected to the external power source through the frequency converter for supplying power to the generator 5 to rotate the rotor 4 such that the generator 5 operates as a motor. The device further includes a control device (not shown) configured to control the generator 5 to rotate the rotor 4 to a predetermined position at which the blade 6 is to be mounted onto the rotor 4. When the rotor 4 is in the predetermined position, the blade 6 is mounted onto the rotor 4.

[0040] The generator 5 operates as a motor, but depending on the expected movement of the installed blade 6, the generator 5 can additionally operate in the generator mode. For example, when lowering the blade 6, the generator 5 can operate in the generator mode to generate power for braking or decelerating the rotor 4.

[0041] Each blade 6 is mounted onto the rotor 4 substantially in the same blade longitudinal orientation (preferably, the horizontal orientation of the blade 6). Additionally, the nacelle 3 having the rotor 4 can be yawed to the installation position before installing the blade 6.

[0042] The device for assisting in mounting a blade 6 onto or removing it from the rotor 4 further includes: a brake for decelerating the rotor 4 (which can include Figure 3the brake disc 14 therein, which is in any case provided in a wind turbine of the prior art); and an encoder for detecting the rotor position and / or the rotor speed. Preferably, two encoders can be used: The first encoder can be an x / y gravity sensor in the rotor 4, providing the absolute rotor azimuth position as shown in Figure 5 the right hand side and Figure 6 , 7 and 8. The first encoder can be an integral part of the rotor 4 and is used herein to show the actual rotor azimuth and as a reference for the (coarse) target position for rotating the rotor 4, where 0 (zero) degrees equals the blade A at the 12 o'clock position. The other second encoder can be a high-resolution temporary incremental encoder, which runs on the inner edge of the brake disc 14 and provides the rotational speed. When the coarse target position is reached, the second encoder can be used to assist in the fine positioning relative to the sensor 15.

[0043] The device for assisting in the installation or removal of the blade 6 further comprises: at least one sensor for detecting a locking indicator arranged at the rotor 4, wherein the locking indicator indicates the locked position of the rotor 4; and a locking device for locking and unlocking the rotor 4. When the rotor 4 is locked by the locking device, the rotor blade 6 is mounted to the rotor 4.

[0044] The control device is configured to: when the locking device is in the unlocked state and the brake is in the released state, control the generator 5 to rotate the rotor 4 towards the target position, while the actual rotor position is determined by the encoder.

[0045] The target position can be a position close to the final locked position. For example, the target position can have an angular distance of 120°. The control device (e.g., implemented by a converter controller) can ramp up the torque of the generator 5 to rotate the rotor 4 by 120°.

[0046] The control device is configured to: when the actual rotor position corresponds to the target position of the rotor 4, control the generator 5 to stop or decelerate the rotor 4, to control the generator 5 to rotate the rotor 4 towards the locked position, which is a predetermined position; when the sensor detects the locking indicator, control the brake to hold the rotor 4 together with the generator 5; and when the rotor 4 is in the locked position, control the locking device to lock the rotor 4. The rotor 4 can be additionally held in place by controlling the torques of both the brake and the generator 5.

[0047] Figure 2The power socket 11 of the generator 5 is shown. More specifically, the wind turbine 1 generally includes a frequency converter (not shown) for converting the frequency of the power generated by the generator 5. The socket 11 is arranged and internally electrically connected at the grid side of the converter. The power socket 11 is configured to connect the generator 5 to the grid during the operation of the wind turbine 1, wherein during the installation of the blade 6, the power socket 11 is disconnected from the grid and connected to the power line of an external power source. The device for assisting in the installation of the blade 6 onto the rotor 4 or for removing it from the rotor 4 also includes at least one circuit breaker that connects and interrupts at least one of the power lines between the external power source and the generator 5.

[0048] The external power source can be a diesel generator or a battery pack with a circuit breaker to provide power for rotating the rotor 4 during the installation of the blade 6. The external power source can be a temporary power source that is lifted from a ship to the top of the nacelle 3 and preferably can be placed on the helicopter platform during the installation of the blade 6. The power requirement for installing the blade 6 of one wind turbine 1 is around one MW, and a sufficient fuel capacity of the diesel generator is required such that the diesel generator does not require any fuel replenishment when it is on the helicopter platform. The circuit breaker in the breaker box located at the external power source can have a plug connection for quick and safe electrical connection. The converter of the wind turbine 1 can be designed to have a permanently pre-installed socket, as Figure 2 shown, which is internally electrically connected at the grid side of the converter power circuit.

[0049] During the installation of the blade 6, a temporary power cable with a pre-installed plug can be connected to this socket and provide power at the grid side of the converter. Such a pre-installed socket at the converter enables a faster and safer connection of the temporary external power source. All three sockets can be connected to the three AC phases from the diesel generator, but if the external power source is a DC battery pack, only two sockets can be used.

[0050] During the installation of the blade 6, the auxiliary system of the wind turbine 1 can be powered by a three-phase 690 V auxiliary power source from the ship through the tower cable.

[0051] Figure 3 A locking device according to an embodiment is shown. The locking device includes a locking pin 12 provided in the fixed frame of the wind turbine 1, wherein when the rotor 4 is in the locked position, the locking pin can be inserted into a locking hole 13 provided in the brake disc 14 of the rotor 4 to lock the rotor 4. For example, if the wind turbine 1 includes three blades 6, the three locking holes 13 can be provided in the brake disc 14 at an angular distance of 120°.

[0052] In this embodiment, the locking indicator is implemented by the locking hole 13. In a variant, the locking indicator can be an optical marker, which is provided separately from the locking hole 13.

[0053] Two sensors 15 are provided, which are configured to detect the circumferential edge of the locking hole 13 respectively. The sensors 15 can be optical sensors. The detection of the circumferential edge of the locking hole 13 can be carried out by light blocking plate detection, by image recognition or by distance detection. The sensors 15 are preferably arranged at diametrically opposite positions of the locking pin 12. The mutual distance between the sensors 15 is preferably less than the diameter of the locking hole 13. The sensors 15 are preferably arranged on an imaginary line that coincides with the diameter of the locking hole 13. This imaginary line is preferably perpendicular to the radius of the brake disc 14. The sensors 15 can be mounted to a special bracket (not shown). For example, the bracket can be temporarily attached at the locking pin 12.

[0054] In order to detect the circumferential edge of the locking hole 13 during the installation of the vane 6, the two sensors 15 can be temporarily mounted on the bracket with precise adjustment options. The pluggable sensor cables can connect the two sensors 15 to a control device, which uses the hole detection signal to align the locking pin 12 and the locking hole 13 so that the rotor 4 can be locked and unlocked. The physical connection of the control cable can be routed (through the cable of the external power supply) to the external power supply. The control cable can be connected from the external power supply to the control device, which communicates with the external power circuit breaker and the sensors 15.

[0055] When the rotor 4 reaches the above-mentioned target position, before the locking operation, fine adjustment can be performed by means of the sensors 15. The control device controls the generator 5 to rotate the rotor 4 from the target position towards the locking position, which is a predetermined position in the meaning of this patent application. Then, when the sensors 15 detect the locking indicator (i.e., the locking hole 13, especially the circumferential edge of the locking hole 13), the control device controls the brake to hold the rotor 4. When the rotor 4 is in the locking position, the control device controls the locking device to lock the rotor 4, that is, the control device can control the hydraulic pump for inserting the locking pin 12 into the locking hole 13.

[0056] In the case of an unbalanced rotor 4, the rotor 4 will rest on the locking pin 12 until a generator torque is applied to counteract the moment due to gravity. In this case, due to the friction between the locking pin 12 and the locking hole 13, a large pulling force will be required to withdraw the locking pin 12 from the locking hole 13. In order to withdraw the locking pin 12, it is important that the locking pin 12 is unloaded. When the rotor 4 is to be unlocked by the locking device, the control device is configured to: determine which of the two sensors 15 is closer to the circumferential edge of the locking hole 13, and control the generator 5 to rotate the rotor 4 to a position where the locking pin 12 is out of contact with the circumferential edge, and control the locking device to withdraw the locking pin 12 from the locking hole 13 to unlock the rotor 4.

[0057] In a variant, the sensor for detecting the locking indicator / locking hole 13 can be implemented by a camera (not shown). In this modified embodiment, the sensors 15 can be omitted. The camera can be used to center the locking pin 12 in the locking hole 13 such that the rotor 4 rotates in such a way that the locking pin 12 is out of contact with the surface of the locking hole 13. The camera can be attached in proximity to the locking pin 12.

[0058] The external power supply, encoder, and sensors 15 can be temporarily installed on the wind turbine 1, which means that they can be removed after the blades 6 have been installed. The temporarily installed encoder can include a pluggable cable connected to a wheel that runs on the inner circumference of the brake disc 14. The other side of the cable can be connected to a pre-installed socket in the converter, and the converter can use this signal to accurately measure the rotor speed or rotor position.

[0059] Figure 4 A torque diagram during rotation of the rotor 4 according to an embodiment is shown. A person skilled in the art can interact with the control device using a handheld terminal. Here, the control device is commanded to rotate the rotor 4 to the next blade installation position. Then, the control device automatically withdraws the locking pin 12 from the locking hole 13, uses the converter and the generator 5 to rotate the rotor 4, and then inserts the locking pin 12 again. During rotation of the rotor 4, the control software of the converter and the control device can monitor and control the position of the rotor 4 by controlling the input power and torque of the generator 5, which mainly operates as a motor in this system.

[0060] If the nacelle 3 having the rotor 4 is yawed to the installation position before the blades 6 are installed, the control device can request confirmation that the yaw position of the nacelle 3 is safe before withdrawing the locking pin 12.

[0061] The rotor 4 with only one or two blades 6 mounted thereon will tend to rotate to the neutral position. If the converter trips due to any error during rotation, the rotor 4 will start to rotate freely. Therefore, it is crucial to confirm that there are no obstacles in the rotor plane before the user withdraws the locking pin 12 by means of a handheld terminal or a user interface. Otherwise, this function ensures that as long as there is an obstacle in the rotor plane, the locking pin 12 remains inserted in the locking hole 13 and eliminates the risk of rotor movement.

[0062] The function of rotating the rotor 4 can be divided into three parts, namely: (a) unlocking the locking device by withdrawing the locking pin 12 and releasing the brake, (b) then rotating the rotor 4 to the locking position, and (c) finally applying the brake and inserting the locking pin 12. This function can be initiated from a handheld terminal or a user interface, which can be a human-machine interface (HMI) for controlling the device or a turbine controller. Once the user starts the program to rotate the rotor 4, the first control step can request confirmation via the user interface that there are no obstacles in the rotor plane. If the user receives confirmation that the yaw position is safe for unlocking the locking device, the control device can communicate with the converter controller to start withdrawing the locking pin 12.

[0063] (Incremental, temporary) encoders and brakes are not essential for the present invention. The encoder or the brake or both can be omitted. In a variant, the rotation of the rotor 4 to the target position can be omitted, such that the rotor 4 moves directly to the locking position as a predetermined position. The control of rotating the rotor 4 to the locking position can be achieved by one sensor 15 or by two sensors 15 or by means of a camera. In this case, the encoder can be omitted. The braking of the rotor 4 can be achieved by controlling the generator torque of the generator 5.

[0064] As described above, in the case of an unbalanced rotor, the rotor 4 will rest on the locking pin 12 until a generator torque is applied to counteract the gravitational torque. In this case, due to the friction between the surfaces of the locking pin 12 and the locking hole 13, a large pulling force is required to release the locking pin 12. To release the locking pin 12, it is important that the locking pin 12 is unloaded.

[0065] As Figure 3As shown, the distance from the circumferential edge of the locking hole 13 to the sensor 15 provides very clear information about which side of the locking pin 12 is resting against the surface of the locking hole 13. Once the control device (i.e., the converter controller) receives information about which sensor 15 is closer to the circumferential edge of the locking hole 13 (e.g., from the turbine controller), the converter controller starts to ramp up the torque of the generator 5 in the opposite direction to unload the locking pin 12. Then, the control device (e.g., implemented by the turbine controller) can issue a command to the hydraulic valve of the locking device to withdraw the locking pin 12 and release the mechanical brake.

[0066] After the locking pin 12 is withdrawn from the locking hole 13 and the mechanical brake is released, by continuously monitoring the rotor speed and position via an encoder and by virtual sensing via high-frequency injection (HFI), the control device (e.g., implemented by the converter controller) can ramp up the torque of the generator 5 to rotate the rotor 4 by 120° (e.g., as an input reference via the HMI user interface from the turbine controller).

[0067] Once the rotor position reaches the locking position, the control device (e.g., implemented by the converter controller) can maintain the generator torque just sufficient to keep the rotor 4 stationary and can expect a signal from the turbine controller for very small movements for precise alignment between the locking hole 13 and the locking pin 12 until both sensors 15 detect the respective locking hole 13.

[0068] Once the control device (turbine controller) determines that both sensors 15 are active / valid, which means both sensors are within the locking hole 13, the control device activates the mechanical brake to ensure that the rotor 4 is firmly held before the locking pin 12 is inserted. Once the locking pin 12 is inserted into the locking hole 13, a signal can confirm to the control device (turbine controller) that the locking pin 12 is in the locked position. Finally, the control device (turbine controller) can instruct the converter control to ramp down the generator torque.

[0069] Now, in the case where the yaw position for safe rotor rotation is different from the yaw position for blade installation, the user can yaw the nacelle 3 to the installation position.

[0070] To ensure that the locking and unlocking of the rotor 4 occur as quickly and safely as possible, the following different measures can be taken:

[0071] The brake may include a brake disc 14 and friction pads operated by a caliper, where the caliper keeps the friction pads in continuous contact with the brake disc 14, even in the released state of the brake.

[0072] The locking indicator can be a locking hole 13 provided in the rotor 4, in particular in the brake disc 14, and the locking device includes a locking pin 12 provided in the fixed frame of the wind turbine 1, wherein when the rotor 4 is in the locked position, the locking pin 12 can be inserted into the locking hole 13 to lock the rotor 4, and the locking pin 12 is operated by a hydraulic pump which is activated before inserting the locking pin 12 into the locking hole 13 or withdrawing it from the locking hole 13.

[0073] A hydraulic accumulator can be provided to support and reserve hydraulic fluid for at least one of the locking device and the brake. In another embodiment, the actuator of the locking pin can be an electric motor, preferably with gears.

[0074] Figures 5 to 7 A user interface during the rotation of the rotor 4 according to an embodiment is shown. The system also allows the rotor 4 to be rotated to other positions than the three positions for horizontal blade mounting. In addition, the system can be used in the "opposite" order for blade disassembly.

[0075] The entire operation (eHSBM) can be automatically controlled by software, and all relevant control and status information related to the operation can be displayed in the user interface (HMI), in particular in its graphical user interface (GUI). The user interface can guide the operator to make important decisions before starting the actual rotation.

[0076] Reference Figure 5 , the yaw operation of the nacelle 3 can be carried out clockwise or counterclockwise, or even automatically towards a specific angle. During the operation of installing the blade 6, the yaw position of the nacelle 3 is important because in the case where the operation is aborted before completion, the entire rotor plane must be free of any obstacles, such as a ship or a crane.

[0077] Another prerequisite for software operation is the configuration of the blade state, because the software calculates the gravitational load and the required converter torque based on the number of blades 6 currently installed on the rotor 4.

[0078] Reference Figure 6 , when configuring the yaw position and the current blade state, the user can proceed to the next step, in which the actual operation is controlled and monitored. Radio buttons can be used to select blade A, B, or C to be installed, and then the start button can be pressed. Then, the software can automatically adjust the rotor position using the sensor 15 to ensure that the rotor 4 does not lean against the locking hole 13, set the brake, and then unlock the locking device. Now, the rotor 4 can be controlled by the converter torque, and the brake can be released to the caliper holding mode, in which the brake pads still contact the brake disc 14 to ensure quick braking later during the process.

[0079] The target rotor position and the actual rotor position are visually shown in Figures 6 to 8 and are also shown as the values below in Figures 6 to 8 The status of the locking device, the torque converter torque, and the brake are also shown. In the case where the energy is provided by the battery, the available energy status of the battery is also shown.

[0080] Reference Figure 7 , when the rotation of the rotor 4 has reached the locking position, the software can automatically ensure that the rotor 4 is in the position where the locking pin 12 is aligned with the corresponding locking hole 13 in the brake disc 14 by using two sensors 15, set the brake, and automatically insert the locking pin 12 into the locking hole 13 to lock the locking device.

[0081] In the case where the rotor 4 is fully locked, the brake is automatically released, and the converter torque slowly ramps down so that the rotor 4 smoothly leans against the surface of the locking hole 13.

[0082] After the blade 6 has been physically installed, the user can switch the "Installed" button in the user interface to complete the operation for the blade 6.

[0083] At any time, the user can decide to stop by pressing the "Stop" button. Here, the software will automatically continue to rotate to the nearest position where the locking device can be locked, and then the software will set the brake, lock the locking device, release the brake, and ramp down the torque converter torque.

[0084] Reference Figure 8 , for example, in the case where the fully installed rotor 4 needs to be rotated by a certain angle to avoid an obstacle on the ship, the "Manual Rotation" button can also be used to request the rotor 4 to rotate to a specific angle. Here, the procedure is the same as the above procedure and will be completed by the fully locked locking device.

[0085] It should be noted that the term "comprising" does not exclude other elements or steps, and the use of the article "a" or "an" does not exclude a plurality. In addition, the elements described in connection with different embodiments can be combined. It should also be noted that the reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. A device for assisting in mounting at least one rotor blade (6) onto a rotor (4) of a wind turbine (1) or for dismounting from said rotor, said device comprising: An external power supply; A generator (5) of the wind turbine (1), said generator (5) including a frequency converter and being mechanically connected to the rotor (4) and electrically connected to the external power supply via the frequency converter for supplying electrical power to the generator (5) to rotate the rotor (4); And A control device configured to control said generator (5) to rotate the rotor (4) to a predetermined position in which the blade (6) will be mounted onto the rotor (4) or dismounted from the rotor; Wherein the wind turbine (1) includes a power socket (11) which is arranged and internally electrically connected at the grid side of the frequency converter and is configured to connect the generator (5) to the grid during operation of the wind turbine (1), and wherein during mounting or dismounting of the blade (6), the power socket (11) is disconnected from the grid and connected to the power line of the external power supply.

2. The device according to the preceding claim, further comprising: A brake for decelerating the rotor (4); An encoder for detecting the rotor position and / or rotor speed; A locking device for locking and unlocking the rotor (4); At least one sensor (15) for detecting a locking indicator arranged at the rotor (4), said locking indicator indicating the locked position of the rotor (4); Wherein the control device is configured to: When the locking device is in the unlocked state and the brake is in the released state, control the generator (5) to rotate the rotor (4) towards the target position while the actual rotor position is determined by the encoder; When the actual rotor position corresponds to the target position of the rotor (4), control the generator (5) to stop or decelerate the rotor (4); Control the generator (5) to rotate the rotor (4) towards the locked position, which is the predetermined position; When the sensor detects the locking indicator, control the brake to hold the rotor (4) together with the generator (5) such that the rotor (4) is in the locked position; and When the rotor (4) is in the locked position, control the locking device to lock the rotor (4).

3. The device according to any one of the preceding claims, further comprising: At least one circuit breaker connecting and interrupting at least one of the power lines between the external power supply and the generator (5).

4. The device according to any one of the preceding claims, wherein: The external power supply is an external generator, an external battery provided on a helicopter platform of the wind turbine (1), an external grid, or a power supply in or at an installation vessel, wherein the power is conveyed to the generator (5) through a temporary or fixed cable in the tower (2) of the wind turbine (1).

5. The device according to any one of claims 2 to 4, wherein: The locking indicator is a locking hole (13) provided in the rotor (4), in particular in the brake disc (14), and the locking device includes a locking pin (12) provided in the fixed frame of the wind turbine (1), wherein when the rotor (4) is in the locked position, the locking pin (12) can be inserted into the locking hole (13) to lock the rotor (4).

6. The device according to the preceding claim, wherein: Two sensors (15) are provided at diametrically opposite positions of the locking pin (12), and the sensors (15) are configured to respectively detect the circumferential edge of the locking hole (13).

7. The device according to any one of claims 2 to 6, wherein: The sensor (15) is a camera configured to detect the circumferential edge of the locking hole (13).

8. The device according to claims 5 to 7, wherein, To unlock the locking device, the control device is configured to: Control the generator (5) to rotate the rotor (4) to a position where the locking pin (12) is out of contact with the circumferential edge of the locking hole (13); And Control the locking device to withdraw the locking pin (12) from the locking hole (13) to unlock the rotor (4).

9. A method of mounting at least one rotor blade (6) onto or removing the same from a rotor (4) of a wind turbine (1), the wind turbine (1) including an external power source, a generator (5) and a control device, the generator (5) including a frequency converter and being mechanically connected to the rotor (4) and electrically connected to the external power source through the frequency converter for supplying power to the generator (5) to rotate the rotor (4), the control device being configured to control the generator (5), the method comprising: Controlling the generator (5) to rotate the rotor (4) to a predetermined position; And When the rotor (4) is in the predetermined position, mounting the blade (6) onto or removing the same from the rotor (4); Wherein the wind turbine (1) includes a power socket (11) which is arranged and internally electrically connected at the grid side of the frequency converter and is configured to connect the generator (5) to the grid during operation of the wind turbine (1), and wherein during mounting or removal of the blade (6), the power socket (11) is disconnected from the grid and connected to the power line of the external power source.

10. The method according to the preceding claim, the wind turbine (1) further including a brake for decelerating the rotor (4), an encoder for detecting the rotor position and / or rotor speed, at least one sensor (15) for detecting a locking indicator arranged at the rotor (4), and a locking device for locking and unlocking the rotor (4), the locking indicator indicating the locked position of the rotor (4), the method comprising: When the locking device is in the unlocked state and the brake is in the released state, control the generator (5) to rotate the rotor (4) towards the target position while the actual rotor position is determined by the encoder; When the actual rotor position corresponds to the target position of the rotor (4), control the generator (5) to stop or decelerate the rotor (4); Control the generator (5) to rotate the rotor (4) towards the locking position, which is the predetermined position; When the sensor detects the locking indicator, control the brake to hold the rotor (4) together with the generator (5) such that the rotor (4) is in the locking position; Control the locking device to lock the rotor (4); and When the rotor (4) is locked by the locking device, mount or dismount the rotor blade (6) onto or from the rotor (4).

11. The method according to claim 10, wherein: The external power source is an external generator or an external battery, which is preferably temporarily arranged on the helicopter platform of the wind turbine (1), and at least one encoder and the at least one sensor (15) are temporarily mounted to the wind turbine (1); and After mounting or dismounting the at least one blade (6), remove at least one of the external power source, the encoder, and the at least one sensor (15).

12. The method according to any one of claims 9 to 11, wherein: The wind turbine (1) includes a plurality of blades (6), and each blade (6) is mounted to or dismounted from the rotor (4) substantially in the same longitudinal blade orientation, preferably the horizontal orientation of the blade (6).

13. The method according to any one of claims 9 to 12, wherein: The generator (5) is mounted in the nacelle (3) of the wind turbine (1), and the method further includes: yawing the nacelle (3) to the mounting or dismounting position before mounting or dismounting the blade (6).

14. The method according to any one of claims 10 to 13, further including at least one of the following: The brake includes a brake disc (14) and friction pads operated by calipers, wherein the calipers keep the friction pads in continuous contact with the brake disc (14), even in the released state of the brake; The locking indicator is a locking hole (13) provided in the rotor (4), and the locking device includes a locking pin (12) provided in the fixed frame of the wind turbine (1), wherein when the rotor (4) is in the locked position, the locking pin (12) can be inserted into the locking hole (13) to lock the rotor (4), wherein, The locking pin (12) is operated by a hydraulic pump, which is activated before inserting the locking pin (12) into or withdrawing it from the locking hole (13); The locking indicator is a locking hole (13) provided in the rotor (4), and the locking device includes a locking pin (12) provided in the fixed frame of the wind turbine (1), wherein when the rotor (4) is in the locking position, the locking pin (12) can be inserted into the locking hole (13) to lock the rotor (4), and a hydraulic accumulator is provided to support and reserve hydraulic fluid for at least one of the locking device and the brake.

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