JP6916221B2 - Windmill lightning current transmission system - Google Patents

Description

The present disclosure relates to a lightning current transmission system for a wind turbine.

Wind turbines such as wind turbines installed offshore or on land are equipped with a lightning current transmission system for discharging lightning current generated by lightning strikes, etc. by transmitting it via a predetermined path. be. The lightning current transmission system forms a path for transmitting lightning current, for example, by wiring a conductive wire having electrical conductivity to a windmill.

Patent Document 1 is an example of this type of lightning current transmission system. In Patent Document 1, a conductive wire for transmitting a lightning current is guided from the tip of the blade of the wind turbine blade to the inside of the hub to which the wind turbine blade is attached via the blade root portion, and further through the inside of the hub of the nacelle. It is disclosed that the lightning current generated by the wind turbine blade is transmitted to the nacelle side by being wired so as to reach the inside.

U.S. Pat. No. 9752560

In Patent Document 1, a conductive wire extending from a wind turbine blade is wired through the inside of a hub and a nacelle. However, bearings, cables, pipes, equipment, etc. related to the operation of the wind turbine are provided inside the hub and the nacelle. Therefore, if the conductive wires serving as the transmission paths of the lightning current are arranged in the same paths as these, there is a possibility that the lightning current may have an electromagnetic effect when flowing through the conductive wires. Even when no lightning current is generated, noise or the like may be generated in the lightning current transmission path due to an electromagnetic influence from the outside. These are factors that cause malfunctions and malfunctions of the wind turbine. Further, by passing a lightning current to the nacelle side without passing through the spindle bearing, deterioration and damage of the bearing can be avoided.

At least one embodiment of the present invention has been made in view of the above circumstances, and the conductive wire that transmits the lightning current affects the bearings, cables, pipes, devices, and the like arranged from the hub to the nacelle. It is an object of the present invention to provide a lightning current transmission system for a wind turbine that can suppress the above.

(1) The lightning current transmission system for a wind turbine according to at least one embodiment of the present invention is designed to solve the above problems.
It is a lightning current transmission system for wind turbines.
An intra-blade conductive wire extending through the inside of the wind turbine blade of the wind turbine to the root of the wind turbine blade,
An intermediate conductive wire that is drawn out of the hub through the internal space of the hub of the wind turbine and is provided along the outer surface of the hub and electrically conducts to the conductive wire in the blade.
A conductive member provided on the nacelle side of the wind turbine and electrically connected to the end of the intermediate conductive wire on the side opposite to the inner conductive wire.
To be equipped.

According to the configuration of (1) above, the lightning current generated at the time of a lightning strike is transmitted to the blade root portion by an in-blade conductive wire provided inside the wind turbine blade. At the wing root, the in-blade conductive wire is conducted to the intermediate conductive wire, and the lightning current is guided to the outside of the hub through the internal space of the hub by the intermediate conductive wire and further transmitted along the outer surface of the hub. .. On the outer surface of the hub, the intermediate conductive wire is electrically connected to the conductive member, and the lightning current is transmitted to the nacelle side by the conductive member. In this way, the lightning current is transmitted from the wind turbine blade to the nacelle side by the conductive wire in the blade, the intermediate conductive wire, and the conductive member.
Here, the intermediate conductive wire is drawn out of the hub through the internal space of the hub. Therefore, even if there are other bearings, cables, pipes, devices, etc. arranged from the internal space of the hub to the inside of the nacelle, the influence on these can be effectively avoided during the transmission of the lightning current. ..
Even when no lightning current is generated, noise or the like may be generated in the lightning current transmission path due to an electromagnetic influence from the outside. Even in such a case, by pulling out the intermediate conductive wire to the outside of the hub and wiring it so as to connect it to the conductive member on the nacelle side, other cables, pipes, devices, etc. arranged in the hub or nacelle, etc. Can be shielded from noise by the housing of the hub.

(2) In some embodiments, in the configuration of (1) above,
The intermediate conductive wire is supported by an in-blade support portion at an end portion on the wind turbine blade side, and is supported by an in-hub support portion provided in the internal space on the hub side from the end portion.
The intermediate conductive wire has a slack portion so that the length from the blade inner support portion to the hub inner support portion is larger than the distance between the blade inner support portion and the hub inner support portion.

According to the configuration of (2) above, the length of the transmission line from the blade inner support portion to the hub inner support portion is set to be larger than the distance between the blade inner support portion and the hub inner support portion, so that the transmission path is set. A slack part (margin) is provided in the. Therefore, even if the distance between the blade inner support portion and the hub inner support portion changes due to the pitch drive of the wind turbine blade with respect to the hub, the change is absorbed by the slack portion and the transmission path (inside the blade). It is possible to prevent the conductive wire and the intermediate conductive wire from breaking.

(3) In some embodiments, in the configuration of (2) above,
The intermediate conductive wire is supported so as to form a curved portion between the blade inner support portion and the hub inner support portion.
The curved portion has a radius of curvature of a predetermined value or more.

According to the configuration of (3) above, the intermediate conductive wire has a curved portion between the blade inner support portion and the hub inner support portion, so that the distance between the blade inner support portion and the hub inner support portion changes during pitch drive. Even when a load is applied to the intermediate conductive wire, the load can be suppressed and the intermediate conductive wire can be effectively prevented from breaking due to fatigue.

(4) In some embodiments, in the configuration of (2) above, the intermediate conductive wire has a connecting portion at the position of the in-blade support portion or on the wing side, and the position of the in-hub support portion or the more hub. It has a connecting part on the side so that the conductive wire between each connecting part can be exchanged.

According to the configuration of (4) above, since there is a risk of fatigue fracture in the intermediate conductive wire corresponding to the slack portion, this portion can be replaced.

(5) In some embodiments, in the configuration of (3) above,
The wind turbine blade has a pitch movable angle range θ with respect to the hub in a projection plane perpendicular to the central axis of the wind turbine blade.
On the projection surface, the first movable distance L1 of the wing inner support portion to the feather state side and the fine side at the shortest position where the distance between the wing inner support portion and the hub inner support portion becomes the minimum value. The second movable distance L2 is
L1 = distance A1 to position B + minimum bending radius r of the conductive material
L2 = distance A2 to position B + minimum bending radius r of the conductive material
Specified in
The length L of the slack portion is set to be larger than the sum of the minimum value of the distance and the larger of the first movable distance L1 and the second movable distance L2.

According to the configuration of (5) above, the length L of the slack portion is the first movable distance L1 or the second movable distance L2, as compared with the minimum value of the distance between the blade inner support portion and the hub inner support portion. It is set larger than the larger one. As a result, when the wind turbine blades are pitch-driven with respect to the hub, the slack portion does not fully extend even when the margin of the slack portion is minimized, so that the intermediate conductive wire is accurately prevented from breaking. can.

(6) In some embodiments, in the configurations (2) to (5) above,
The wind turbine blade has at least one opening which is a plate-shaped member arranged perpendicular to the central axis of the wind turbine blade, which is formed so as to project inward from the inner wall of the wind turbine blade or the inner ring of the pitch bearing. Have a support plate to have
The intermediate conductive wire has the in-blade support portion that passes through the opening of the support plate and is fixed at least one place on the support plate and is arranged so as to have a slack portion thereafter.
The support portion in the hub will support the intermediate conductive wire on the hub side after passing through the slack portion.

According to the configuration of (6) above, the intermediate conductive wire can be efficiently arranged by utilizing the support plate while securing the slack portion on the hub side.

(7) In some embodiments, in the configuration of (6) above,
One of the first element or the second element is an annular member extending at least partially along the circumferential direction of the wind turbine blade, and the other is a brush slidable on the annular member.

According to the configuration (7) above, by configuring the first electrical connection portion with the annular member and the brush, the electrical connection between the two is suitably maintained even when the wind turbine blades are pitch-driven with respect to the hub. can.

(8) In some embodiments, in the configuration of (6) or (7) above,
The wind turbine blade is connected to the hub via a pitch bearing.
The first element and the second element are electrically insulated from the pitch bearing.

According to the configuration (8) above, since the first element and the second element constituting the first electrical connection portion are insulated from the pitch bearing, the pitch bearing can be suitably protected from lightning current.

(9) In some embodiments, in any one of the above (1) to (8),
The intermediate conductive wire is electrically connected to the conductive member via a second electrical connection portion.
The second electrical connection is
A third element connected to the intermediate conductive wire and supported by the hub,
A fourth element connected to the conductive member and supported by the nacelle,
including.

According to the configuration of (9) above, by providing the second electrical connection portion including the third element and the fourth element, when the hub and the nacelle rotate relative to each other during the operation of the wind turbine, the electrical connection is made. The state can be secured accurately.

(10) In some embodiments, in the configuration of (9) above,
One of the third element or the fourth element is an annular member extending at least partially along the circumferential direction of the main shaft of the wind turbine, and the other is a brush slidable on the annular member.

According to the configuration (10) above, by configuring the second electrical connection portion with the annular member and the brush, the electrical connection between the two can be suitably maintained even when the hub rotates with respect to the nacelle.

(11) In some embodiments, in the configuration of (9) above,
One of the third element or the fourth element is an annular member extending at least partially along the circumferential direction of the main shaft of the wind turbine, and the other is conductive so as to face the annular member through a gap. It is a department.

According to the configuration of (11) above, by configuring the second electrical connection portion with the annular member and the conductive portion facing each other via the gap, even when the hub rotates with respect to the nacelle, both are electrically connected. The connection can be held favorably.

(12) In some embodiments, in any one of the above (9) to (11) configurations.
The hub is connected to the nacelle via a spindle bearing.
The third element and the fourth element are electrically insulated from the spindle bearing.

According to the configuration (12) above, since the third element and the fourth element constituting the second electrical connection portion are insulated from the spindle bearing, the spindle bearing can be suitably protected from lightning current.

(13) In some embodiments, in the configuration of (12) above,
The spindle bearing includes an inner ring connected to the spindle connected to the hub and an outer ring connected to the nacelle.

According to the configuration of (13) above, the nacelle side element of the second electrical connection portion can be easily attached by setting the outer ring side of the spindle bearing to the stationary side. In addition, the inner ring side is connected to a rotating hub, and there are many structures in which wind turbine blades, pitch bearings, etc. are projected on the hub, and the second electrical connection can be easily attached using such a protruding structure. can.
The spindle bearing can also be configured to include an outer ring connected to the spindle connected to the hub and an inner ring connected to the nacelle.

(14) In some embodiments, in any one of the above (9) to (12) configurations.
The second electrical connection portion electrically connects the third element and the fourth element at a plurality of positions along the circumferential direction of the main shaft of the wind turbine.

According to the configuration of (14) above, by making the electrical connection by the second electrical connection portion at a plurality of places, the electrical connection between the two can be suitably maintained even when the hub rotates with respect to the nacelle. ..

(15) In some embodiments, in any one of the above (1) to (14) configurations.
The intermediate conductive wire extends on the outer surface of the hub so as to partially surround the wing root portion of the wind turbine blade.

According to the configuration (15) above, the intermediate conductive wires extending along the outer surface of the hub can be arranged in an efficient layout.

According to at least one embodiment of the present invention, the lightning current of a wind turbine that can suppress the influence of the conductive wire that transmits the lightning current on the bearings, cables, pipes, devices, etc. arranged from the hub to the nacelle. A transmission system can be provided.

It is an overall block diagram of the wind turbine which concerns on at least one Embodiment of this invention. It is a perspective view of the wind turbine rotor of FIG. It is a schematic diagram which transparently shows the portion of the conductive wire of FIG. 2 from the blade inner space of the wind turbine blade to the inner space of the hub from the front side of the wind turbine rotor. FIG. 2 is an M cross-sectional view of FIG. It is an enlarged view of the N part of FIGS. 3 and 4. It is explanatory drawing which shows the positional relationship of the blade inner support part, the hub inner support part, and the slack part at the time of pitch drive by projecting onto the vertical plane in the blade length direction (case 1). It is explanatory drawing which shows the positional relationship of the blade inner support part, the hub inner support part, and the slack part at the time of pitch drive by projecting onto the vertical plane in the blade length direction (case 2). It is explanatory drawing which shows the positional relationship of the blade inner support part, the hub inner support part, and the slack part at the time of pitch drive by projecting onto the vertical plane in the blade length direction (case 3). It is a modification of FIG. This is an example of an electrical connection diagram of a conductive wire between a hub and a nacelle. It is a top view which shows the 4th element of FIG. 8 from the axial direction of the rotation axis. It is another example of the electrical connection diagram of the conductive wire between the hub and the nacelle. It is a schematic diagram of the S direction view of FIG. It is a schematic diagram which extracts the 3rd element and the 4th element of FIG. 10 and shows along the axial direction of a wind turbine rotor.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely explanatory examples. Only.

FIG. 1 is an overall configuration diagram of a wind turbine 1 according to at least one embodiment of the present invention, and FIG. 2 is a perspective view of the wind turbine rotor 2 of FIG. In the following embodiment, a wind power generator having a generator will be described as an example of the wind turbine 1, but any wind turbine according to the embodiment of the present invention has a configuration capable of converting wind energy into a driving force. It can also be applied to the equipment of.

The wind turbine 1 includes a wind turbine rotor 2 that rotates in response to wind, a main shaft 6 connected to a hub 4, and a generator 7 that generates electric power using the rotational energy of the main shaft 6. The rotation axis O of the main shaft 6 is slightly inclined upward with respect to the horizontal direction.

The wind turbine 1 may include a drive train (accelerator) for transmitting the rotational energy of the main shaft 6 to the generator 7. Further, various devices including the main shaft 6 are housed in the nacelle 8. The nacelle 8 rotatably supports the wind turbine rotor 2 and is rotatably installed on the tower 9.

The wind turbine rotor 2 includes at least one wind turbine blade 3, a hub 4 to which these wind turbine blades 3 are attached, and a spinner 5 that covers the hub 4. In the present embodiment, as shown in FIG. 2, a configuration in which three wind turbine blades 3 are attached to the hub 4 is illustrated, but the number of wind turbine blades 3 may be arbitrary. The spinner 5 may be installed arbitrarily.

The wind turbine blade 3 extends along the blade length direction and has a blade tip portion 3a and a blade root portion 3b. The wind turbine blade 3 has a hollow structure in which an outer skin is bonded to each other and an inner space 3c (see FIG. 3) is formed inside. At least a part of the wind turbine blade 3 may be made of fiber reinforced plastic such as GFRP (glass fiber reinforced plastic) or CFRP (carbon fiber reinforced plastic).

By attaching the wind turbine blade 3 to the hub 4 via the pitch bearing 10, the wind turbine blade 3 can be pitch-driven with respect to the hub 4. The hub 4 is made of a conductive material, for example, cast iron. The hub 4 has a hollow structure including an internal space 4b, and has an opening 4c on the front side that opens the internal space 4b so as to communicate with the outside. Although not shown in FIG. 2, the internal space 4b of the hub 4 is provided with cables, pipes, scaffolding for work, and other equipment related to the operation of the wind turbine 1. The internal space 4b of such a hub 4 is configured to communicate with the blade internal space 3c of the wind turbine blade 3 via the pitch bearing 10.

The spinner 5 is provided so as to cover the hub 4, and rotates together with the wind turbine blade 3 and the hub 4. The spinner 5 is made of an insulating material. Specifically, the spinner 5 may be made of non-conductive fiber reinforced plastic, for example, GFRP (glass fiber reinforced plastic). Although not shown in FIG. 2, between the hub 4 and the spinner 5, for example, a support structure for supporting the spinner 5 with respect to the hub 4, a scaffold for work, and the like are provided.

Further, the hub 4 constituting the wind turbine rotor 2 is rotatably supported by the nacelle 8 rotatably installed on the tower 9 via the spindle bearing 20. The nacelle 8 is also provided with cables, pipes, scaffolding for work, and other equipment related to the operation of the wind turbine 1 inside.

The wind turbine 1 having the above configuration includes a lightning current transmission system for transmitting a lightning current generated when a lightning strike occurs on the wind turbine blade 3. The lightning current transmission system includes a conductive wire 30 made of a cable-shaped conductor having a predetermined cross-sectional area made of a conductive material, and is configured to be capable of transmitting a lightning current through a predetermined path.

A receptor 14 (see FIG. 1) for receiving a lightning strike is provided on the blade tip portion 3a side of the outer surface of the wind turbine blade 3. The receptor 14 is connected to the end of the conductive wire 30 arranged in the blade inner space 3c of the wind turbine blade 3, and the lightning current input from the receptor 14 is transmitted by the conductive wire 30. The conductive wire 30 is wired over the wind turbine blade 3 and the hub 4, and is electrically connected to the conductive member 16 provided in the nacelle 8. Since the conductive member 16 is grounded underground or underwater, the lightning current input from the receptacle 14 is transmitted from the conductive wire 30 via the conductive member 16 so as to finally escape to the ground or water. NS.

As shown in FIG. 2, the conductive wire 30 is wired so as to pass through the inner space 3c of the wind turbine blade 3, the internal space 4b of the hub 4, and the outside of the hub 4, respectively, and reach the conductive member 16 of the nacelle 8. .. Here, the wiring path of the conductive wire 30 will be described in detail with reference to FIG. FIG. 3 is a schematic cross-sectional view of the portion of the conductive wire 30 of FIG. 2 from the blade inner space 3c of the wind turbine blade 3 to the internal space 4b of the hub 4 as viewed from the front side of the wind turbine rotor 2.

The conductive wire 30 connected to the receptacle 14 provided at the blade tip portion 3a of the wind turbine blade 3 extends the blade interior space 3c of the wind turbine blade 3 toward the blade root portion 3b along the blade length direction (see FIG. 1). ). At the wing root portion 3b, the conductive wire 30 passes through the inside of the pitch bearing 10 and reaches the internal space 4b of the hub 4. Then, the conductive wire 30 is guided to the outside from the internal space 4b of the hub 4 via the wall of the hub 4 at a predetermined position of the hub 4. The conductive wire 30 guided to the outside of the hub 4 is supported by the outer surface of the hub 4 and extends toward the nacelle 8, and is electrically connected to the conductive member 16 provided on the nacelle 8 side.

Such wiring of the conductive wire 30 does not pass through the inside of the main shaft 6 from the internal space 4b of the hub 4 to the internal space of the nacelle 8. Therefore, when the cables, pipes, scaffolding for work, and other equipment related to the operation of the wind turbine 1 are arranged so as to pass through the inside of the main shaft 6 from the internal space 4b of the hub 4 to the internal space of the nacelle 8. However, when a lightning current flows through the conductive wire 30, it is possible to avoid the influence on these configurations.

In general, even when no lightning current is generated, noise or the like is generated in the lightning current transmission path due to an external electromagnetic influence, and the cables, pipes, or cables existing inside the hub 4 or nacelle 8 are generated. It may affect the equipment. In that respect, since the conductive wire 30 of the present embodiment is drawn out from the wall of the hub 4 at a predetermined position of the hub 4 and supported by the outer surface of the hub 4 for wiring, noise generated in the conductive wire 30 and the like are generated. By keeping a predetermined distance, the influence on the cables, pipes, devices, etc. existing inside the hub 4 and the nacelle 8 can be effectively suppressed.

The conductive wire 30 is composed of the functions of a plurality of conductive wires. Specifically, the conductive wire 30 is an intermediate conductive wire that connects the inner conductive wire 30A extending in the blade inner space 3c of the wind turbine blade 3 and the inner conductive wire 30A and the conductive member 16 on the nacelle 8 side. Functionally includes wire 30B.

The in-blade conductive wire 30A is electrically connected to the receptacle 14 on the blade tip portion 3a side of the wind turbine blade 3, and extends the blade in-blade space 3c of the wind turbine blade 3 to the blade root portion 3b. The end portion of the blade inner conductive wire 30 on the blade root portion 3b side is electrically connected to the intermediate conductive wire 30B in the blade inner space 3c of the wind turbine blade 3. As shown in FIG. 3, the in-blade conductive wire 30A and the intermediate conductive wire 30B may be connected by a connecting portion 13 provided on the wind turbine blade 3 side of the pitch bearing 10 to facilitate assembly. As described above, the intermediate conductive wire 30B is guided to the internal space 4b of the hub 4 via the pitch bearing 10, and is further guided to the outside from the wall of the hub 4 at a predetermined position, and is a nacelle along the outer surface of the hub 4. It extends toward the conductive member 16 on the 8 side. By forming the conductive wire 30 from a plurality of conductive wires in this way, if a part of the conductive wires is damaged or broken, it can be recovered by replacing only the conductive wires. Therefore, the work load and cost can be effectively suppressed as compared with the case where the entire conductive wire 30 is replaced.
In the following description, when the in-blade conductive wire 30A and the intermediate conductive wire 30B are not distinguished, they are simply referred to as "conductive wire 30".

Subsequently, the wiring structure of the conductive wire 30 in the vicinity of the pitch bearing 10 will be described in detail. FIG. 4 is a diagram showing the arrangement of the conductive wire 30 (intermediate conductive wire 30B) in the vicinity of the thickness direction of the M cross-sectional view of FIG. 2, and FIG. 5 is an enlarged view of the N region of FIGS. 3 and 4. As shown in FIG. 2, the M cross section is defined as a plane passing through the central axis C of the wind turbine blade 3 and the rotation axis O of the wind turbine rotor 2.

A pitch bearing 10 that rotatably supports the wind turbine blade 3 with respect to the hub 4 is provided between the wind turbine blade 3 and the hub 4. The pitch bearing 10 includes an inner ring 10a to which the wind turbine blade 3 is fixed, an outer ring 10b to which the hub 4 is fixed, and a rolling element 10c provided between the inner ring 10a and the outer ring 10b. The inner ring 10a has a ring shape corresponding to the blade root portion 3b of the wind turbine blade 3, and the inner space 3c of the wind turbine blade 3 and the internal space 4b of the hub 4 communicate with each other inside the inner ring 10a. The conductive wire 30 (intermediate conductive wire 30B) is guided from the wind turbine blade 3 side to the hub 4 side through the communication space provided inside the inner ring 10a in this way without being exposed to the outside.
Although different from FIG. 4, even when the wind turbine blade 3 is fixed to the outer ring 10b and the hub 4 is fixed to the inner ring 10a, the same effect as described above can be obtained.

In the vicinity of such a pitch bearing 10, the conductive wire 30 (intermediate conductive wire 30B) is supported by the blade inner support portion 32 on the wind turbine blade 3 side and the hub inner support portion 34 on the hub 4 side, respectively. In FIG. 4, the inner wall of the wind turbine blade 3 or the inner ring 10a of the pitch bearing 10 to which the wind turbine blade 3 is fixed is formed so as to project inward, and in the present embodiment, it is perpendicular to the central axis of the wind turbine blade 3. , The first support plate 36 and the second support plate 38, which are plate-like members arranged in parallel with each other, are shown. The first support plate 36 is provided on the blade tip 3a side as compared with the second support plate 38.
Although different from FIG. 4, when the wind turbine blade 3 is fixed to the outer ring 10b and the hub 4 is fixed to the inner ring 10a, the wind turbine blade 3 is formed so as to project inward from the outer ring 10b of the pitch bearing 10 of the wind turbine blade 3. Only the first support plate 36, which is a plate-shaped member perpendicular to the central axis C of the wind turbine blade 3, may be used.

The conductive wire 30 (intermediate conductive wire 30B) is supported by such a first support plate 36 and a second support plate 38 on the wind turbine blade 3 side. Although different from FIG. 4, when the wind turbine blade 3 is fixed to the outer ring 10b and the hub 4 is fixed to the inner ring 10a, the conductive wire 30 (intermediate conductive wire 30B) is supported by the first support plate 36. As shown in FIGS. 4 and 5, when the intermediate conductive wire 30B reaches the first support plate 36 along the inner wall of the wind turbine blade 3, it is deflected along the surface direction of the first support plate 36. The intermediate conductive wire 30B extends along the surface of the first support plate and is fixed by the fixing portions 36a and 36b provided on the surface of the first support plate 36. The intermediate conductive wire 30B is further deflected toward the second support plate 38 through the opening 39 of the first support plate 36, through the opening 40 of the second support plate 38, and under the second support plate 38. After forming the curved portion 41 on the side, the wiring is made so as to be fixed by the fixing portion 38a of the second support plate 38 along the surface of the second support plate 38. By forming the curved portion 41 as described above on the conductive wire 30 (intermediate conductive wire 30B), the conductive wire 30 (intermediate conductive wire 30B) is formed when the conductive wire 30 (intermediate conductive wire 30B) is deflected to form the wiring pattern. The load on the wire 30B) is reduced, and the risk of breakage or damage is reduced. The in-blade conductive wire 30A extends the wiring in an appropriate direction by the above-mentioned function of the intermediate conductive wire 30B, and the intermediate conductive wire 30B is further fixed by the in-blade support portion 32 and then extends to the slack portion 42.

As shown in FIG. 4, the hub internal support portion 34 of the intermediate conductive wire 30B is formed so as to be supported by a support portion from an inner wall that defines the internal space 4b of the hub 4.

In this way, the conductive wire 30 (intermediate conductive wire 30B) is supported on the wind turbine blade 3 side by the blade inner support portion 32 and supported on the hub 4 side by the hub inner support portion 34 in the vicinity of the pitch bearing 10. .. Therefore, when the wind turbine blade 3 is pitch-driven with respect to the hub 4, the distance between the blade inner support portion 32 and the hub inner support portion 34 changes, and such a change in the distance is caused by the conductive wire 30 (intermediate conductive wire 30B). ) Is preferably absorbed by the slack portion 42 provided in).

The length of the conductive wire 30 (intermediate conductive wire 30B) in the slack portion 42 is designed to be sufficiently larger than the distance between the blade inner support portion 32 and the hub inner support portion 34. As a result, even when the wind turbine blade 3 is pitch-driven with respect to the hub 4, the slack portion 42 does not extend completely, and breakage or damage of the conductive wire 30 (intermediate conductive wire 30B) can be prevented.

6A to 6C are explanatory views showing the positional relationship between the blade inner support portion 32, the hub inner support portion 34, and the slack portion 42 during pitch drive by projecting them onto a vertical plane in the blade length direction. In FIGS. 6A to 6C, the positions A1 and A2 correspond to the positions of the in-blade support portions 32 when the wind turbine blades 3 are in the feather state and the fine state, respectively. That is, assuming that the pitch movable angle range with respect to the central axis O of the wind turbine blade 3 is an angle θ, the angle formed by the straight line A1-O connecting the position A1 and the position O and the straight line A2-O connecting the position A2 and the position O. Defined as a range. The support portion B in the hub and the central axis O are connected by a straight line projected on a vertical plane in the blade length direction, the intersection of the pitch movable arc between A1 and A2 is set to A3, the angle of A1 is zero, and the angle of A2 is set. Is defined as θ, and A3 is an angle α. Case 1 of FIG. 6A is a case where the straight line of BO is in the arcs of A1 and A2. In case 2 of FIG. 6B, A3 protrudes to the feather side of the arc and α is negative, and case 3 of FIG. 6C is an arc. A3 protrudes to the fine side of the above, and α becomes θ or more. In FIG. 6A, the in-blade support 32 moves only between A1 and A2 according to the definition, so α is between zero and θ. In this range, A3 minimizes the distance between the blade inner support portion 32 and the hub inner support portion 34. However, since the hub inner support portion 34 is not the same plane as the blade inner support portion 32 in the plane perpendicular to the central axis of the wind turbine blade 3, not only the distance between B and A3 but also the distance between the planes. It is necessary to add it.

From the above definition, the position of the blade inner support portion 32 that minimizes the distance between the blade inner support portion 32 and the hub inner support portion 34 is A3. When A3 is within the pitch movable range θ, the distance from A1 to B is L1 and the distance from A2 to B is L2.

The length L of the slack portion 42 described above uses the larger L2 of the distance L1 between the position A1 and the position B and the distance L2 between the position A2 and the position B building, and the following equation L> Max (L1, L2). )
It should be designed to meet the requirements. As a result, when the wind turbine blade 3 is pitch-driven with respect to the hub 4, the slack portion 42 does not fully extend even when the margin of the slack portion 42 is minimized (because there is not a little margin left). , It is possible to accurately prevent the conductive wire 30 (intermediate conductive wire 30B) from breaking.

Further, as shown in FIGS. 6A to 6C, the slack portion 42 is configured so that at least one curved portion 44 is formed when the wind turbine blade 3 is pitch-driven with respect to the hub 4. The curved portion 44 is formed according to the load applied to the conductive wire 30 (intermediate conductive wire 30B) during pitch drive, and is designed so that the radius of curvature r of the curved portion 44 is equal to or greater than a predetermined value. It is good. By designing in this way, when a load is applied to the conductive wire 30 (intermediate conductive wire 30B) as the distance between the blade inner support portion 32 and the hub inner support portion 34 changes during pitch drive. However, the load can be suppressed and the conductive wire 30 (intermediate conductive wire 30B) can be effectively prevented from breaking due to fatigue.

As shown in FIG. 4, the wind turbine blade 3 is a plate-shaped member arranged perpendicular to the central axis C of the wind turbine blade 3 and is formed so as to project inward from the inner wall of the wind turbine blade 3 or the pitch bearing 10. The intermediate conductive wire 30B has a first support plate 36 and a second support plate 38 having at least one openings 39 and 40, respectively, and the intermediate conductive wire 30B is an opening 39 of the first support plate 36 and a second support plate. It has an in-blade support 32 that passes through the opening 40 of 38 and is fixed at least one on these support plates and is arranged to have a slack 42 thereafter, and has an in-hub support 34. Supports the intermediate conductive wire 30B on the hub 4 side after passing through the slack portion 42.

In the present embodiment, by having the slack portion 42 as described above, the conductive wire 30 (intermediate conductive wire 30B) is prevented from being broken or damaged, but even if the conductive wire 30 (intermediate conductive wire 30B) is broken or damaged, the intermediate conductive wire is prevented from being broken or damaged. Of 30B, an intermediate portion having a connecting portion at the position of the wing inner support portion 32 or the wing side, having a connecting portion at the position of the hub inner support portion 34 or the more hub 4 side, and including a slack portion 42 between the connecting portions. Restoration can be easily performed by replacing only the conductive wire 30.

In the above-described embodiment, the conductive wire 30 (intermediate conductive wire 30B) includes a slack portion 42 having a sufficient length to avoid breakage or damage during pitch driving, but this is caused by the slack portion 42. Alternatively, it can be achieved by electrical connection with the brush or gap shown in FIG.

In the modified example of FIG. 7, by providing the first electrical connection portion 50 instead of the slack portion 42, it is possible to avoid breakage or damage of the conductive wire 30 during pitch drive. The first electrical connection portion 50 includes an annular member extending at least partially along the circumferential direction of the wind turbine blade 3 and a brush slidable on the annular member. Even in such an embodiment, breakage or damage of the conductive wire 30 can be suitably prevented.

Further, each element constituting the first electrical connection portion 50 is electrically insulated from the pitch bearing 10. As a result, when a lightning current is generated, it is possible to prevent the lightning current from flowing from the conductive wire 30 to the pitch bearing 10, so that the pitch bearing 10 can be suitably protected.

In the example of FIG. 7, the case where the first electrical connection portion 50 is configured as a brush is illustrated, but it may be configured as a gap.

Subsequently, the electrical connection configuration between the conductive wire 30 (intermediate conductive wire 30B) and the conductive member 16 on the nacelle 8 side will be described in detail with reference to FIGS. 8 to 9. FIG. 8 is an example of an electrical connection diagram of the conductive wire between the hub and the nacelle, and FIG. 9 is a plan view showing the fourth element 60B of FIG. 8 from the axial direction O of the main shaft 6.

The wind turbine rotor 2 including the hub 4 is rotatably supported with respect to the nacelle 8 via the spindle bearing 20. The spindle bearing 20 includes an inner ring 20a fixed to the hub 4, an outer ring 20b fixed to the nacelle 8, and a rolling element 20c interposed between the inner ring 20a and the outer ring 20b. By setting the outer ring 20b side of the spindle bearing 20 to the stationary side in this way, the nacelle 8 side element of the second electrical connection portion 60 can be easily attached. Further, the inner ring 60A side is coupled to a rotating hub 4, and the hub 4 has many structures in which a wind turbine blade 3, a pitch bearing 10, and the like are projected, and the second electrical connection portion 60 utilizes such a protruding structure. Can be easily installed.

The conductive wire 30 (intermediate conductive wire 30B) on the hub 4 side is connected to the conductive member 16 on the nacelle 8 side via the second electrical connection portion 60, so that the hub 4 and the nacelle are connected during the operation of the wind turbine 1. It is configured to ensure an electrical connection when the 8s rotate relative to each other. The second electrical connection portion 60 is a third element 60A connected to the conductive wire 30 (intermediate conductive wire 30B) and supported by the hub 4, and a fourth element connected to the conductive member 16 and supported by the nacelle 8. Including 60B. In the present embodiment, the third element 60A is configured as a brush provided at the end of the conductive wire 30 (intermediate conductive wire 30B) on the hub 4 side. As shown in FIG. 8, the third element 60A is supported by the hub 4 via the first support member 62 and the second support member 64. The first support member 62 is a bracket member that is fastened together with bolts 65 for connecting the hub to the outer ring of the pitch bearing 10. The second support member 64 is a bracket member further connected to the end of the first support member 62. The first support member 62 and the second support member are configured so that the third element 60A provided at the tip thereof can come into contact with the fourth element 60B provided on the nacelle 8 side.

The first support member 62 and / or the second support member 64 is made of an insulating material such as FRP, from the conductive wire 30 (intermediate conductive wire 30B) and the third element 60A to the pitch bearing 10. The lightning current is prevented from flowing, and the pitch bearing 10 is protected.

As shown in FIG. 9, the fourth element 60B is an annular member that extends at least partially along the circumferential direction of the wind turbine rotor 2 of the wind turbine 1. The fourth element 60B is arranged at a position in the nacelle 8 that can come into contact with the third element 60A. In the present embodiment, the fourth element 60 has a ring shape extending along the entire circumferential direction, and the conductive members 16 are electrically connected to each other at positions 180 degrees different from each other. The third element 60A and the fourth element 60B are electrically connected by contacting each other, and are static on the nacelle 8 side even when the hub 4 is rotationally driven with respect to the nacelle 8 during operation of the wind turbine 1. The third element 60A supported on the hub 4 side comes into contact with the fourth element 60B supported by the nacelle while sliding, so that the electrical connection state is maintained.

The fourth element 60B is attached to the main body of the nacelle 8 via, for example, an insulating material 63 made of plastic, so that when a lightning current flows to the main body of the nacelle 8, the lightning current flows to the main body of the nacelle 8. Is insulated so that it does not flow.

In the present embodiment, the case where the third element 60A is configured as a brush and the fourth element 60B is configured as an annular member is illustrated, but the third element 60A is configured as an annular member. At the same time, the fourth element 60B may be configured as a brush.

In the above-described embodiment, the second electrical connection portion 60 is composed of a third element 60A and a fourth element 60B that slide on each other, but this may be substituted or used in combination with the following configuration. 10 is another example of the electrical connection diagram of the conductive wire 30 between the hub 4 and the nacelle 8, FIG. 11 is a schematic view of the S direction of FIG. 10, and FIG. 12 is the third element 60A of FIG. It is a schematic diagram which extracts the 4th element 60B and shows along the axial direction of the wind turbine rotor 3. In FIGS. 10 to 12, common reference numerals are given to the parts corresponding to the above description, and duplicate description will be omitted as appropriate.

As shown in FIG. 10, also in this modification, the conductive wire 30 (intermediate conductive wire 30B) on the hub 4 side is electrically connected to the conductive member 16 on the nacelle 8 side via the second electrical connection portion 60. Be connected. The second electrical connection 60 is composed of a third element 60A and a fourth element 60B that form a spark gap structure.

The third element 60A is supported on the hub 4 side, and is configured as an annular member extending at least partially along the circumferential direction of the main shaft of the wind turbine 1. In this embodiment, as shown in FIG. 12, the third element 60A is configured as a plate having a ring shape extending over the entire circumference. A conductive wire 30 (intermediate conductive wire 30B) extending from the hub 4 side is connected to the third element 60A.

Note that FIG. 12 shows a case where the third element 60A having a ring shape extending over the entire circumference is composed of one member in order to simply show the configuration, but the third element 60A has a plurality of elements. It may be completed by assembling partial annular members to each other (that is, the third element 60A may be divided into a plurality of arcuate members).

One fourth element 60B is supported on the nacelle 8 side, and is configured as a conductive portion facing the third element 60A via a gap. The fourth element 60B is arranged so as to face the third element 60A from the hub 4 side, and the conductive member 16 of the nacelle 8 is connected to the fourth element 60B. In the present embodiment, as shown in FIG. 10, the third element 60A provided on the hub 4 has a space on the opposite side to the nacelle 8, and the fourth element 60B is a hub using the space. It is arranged so as to face the third element 60A from the 4th side.

Further, as shown in FIGS. 10 and 11, the fourth element 60B has a bracket plate shape extending perpendicularly to the third element 60A, and a concave-convex shape 66 is formed at the tip thereof. By providing the concave-convex shape 66 at the tip of the fourth element 60B in this way, the discharge property between the gaps is improved.

The third element 60A and the fourth element 60B are arranged so as to face each other with a predetermined gap (gap) of about 0 to 5 mm.

As shown in FIG. 12, the fourth element 60B having the above configuration is provided at three positions different in the circumferential direction with respect to the third element 60A having a ring shape over the entire circumference. Each conductive wire 30 (intermediate conductive wire 30B) corresponding to the three wind turbine blades 3 is connected to these third elements 60A, and even if there is a lightning strike on any of the wind turbine blades 3, The lightning current is accurately discharged to the conductive member 16 on the nacelle 8 side.

As described above, according to the above embodiment, the wind turbine 1 capable of suppressing the influence of the conductive wire that transmits the lightning current on the cables, pipes, devices, and the like arranged from the hub 4 to the nacelle 8. A lightning current transmission system can be provided. In this configuration, since the hub 4 is electrically insulated from the nacelle 8 side, equipotential bonding is necessary. Therefore, the hub 4 and the fourth element 60B are electrically connected.

At least one embodiment of the present invention can be used in a wind turbine lightning current transmission system.

1 Windmill 2 Windmill rotor 3 Windmill blade 3a Blade tip 3b Blade root 3c Blade inner space 4 Hub 4b Internal space 5 Spinner 6 Main shaft 7 Generator 8 Nacelle 9 Tower 10 Pitch bearing 14 Receptor 16 Conductive member 20 Main shaft bearing 30 Conductive wire 30A In-blade conductive wire 30B Intermediate conductive wire 32 In-blade support 34 In-hub support 36 First support plate 38 Second support plate 39 Opening 40 Opening 41 Curved part 42 Loose part 44 Curved part 50 First electrical connection Part 60 Second electrical connection part 60A Third element 60B Fourth element 62 First support member 64 Second support member 66 Concavo-convex shape

Claims (15)

It is a lightning current transmission system for wind turbines.
An intra-blade conductive wire extending through the inside of the wind turbine blade of the wind turbine to the root of the wind turbine blade,
An intermediate conductive wire that is drawn out of the hub through the internal space of the hub of the wind turbine and is provided along the outer surface of the hub and electrically conducts to the conductive wire in the blade.
A conductive member provided on the nacelle side of the wind turbine and electrically connected to the end of the intermediate conductive wire on the side opposite to the inner conductive wire.
A wind turbine lightning current transmission system. The intermediate conductive wire is supported by an in-blade support portion at an end portion on the wind turbine blade side, and is supported by an in-hub support portion provided in the internal space on the hub side from the end portion.
1. The intermediate conductive wire having a slack portion so that the length from the blade inner support portion to the hub inner support portion is larger than the distance between the blade inner support portion and the hub inner support portion. The lightning current transmission system for wind turbines as described in. The intermediate conductive wire is supported so as to form a curved portion between the blade inner support portion and the hub inner support portion.
The lightning current transmission system for a wind turbine according to claim 2, wherein the curved portion has a radius of curvature of a predetermined value or more. The intermediate conductive wire has a connecting portion at the position of the in-blade support portion or on the wing side, has a connecting portion on the position of the in-hub support portion or on the more hub side, and exchanges conductive wires between the connecting portions. The lightning current transmission system for a wind turbine according to claim 2, wherein the lightning current transmission system of the wind turbine is enabled. The wind turbine blade has a pitch movable angle range θ with respect to the hub in a projection plane perpendicular to the central axis of the wind turbine blade.
On the projection surface, the first distance L1 of the blade inner support portion to the feather state side at the maximum position where the distance between the blade inner support portion and the hub inner support portion is maximum, and the second on the fine side. Distance L2 is
L1 = distance A1 to position B + minimum bending radius r of the conductive material
L2 = distance A2 to position B + minimum bending radius r of the conductive material
Specified in
The lightning current transmission system for a wind turbine according to claim 3, wherein the length L of the slack portion is set to be larger than the first distance L1 or the second distance L2, whichever is larger. The wind turbine blade has at least one opening which is a plate-shaped member arranged perpendicular to the central axis of the wind turbine blade, which is formed so as to project inward from the inner wall of the wind turbine blade or the inner ring of the pitch bearing. Have a support plate to have
The intermediate conductive wire has the in-blade support portion that passes through the opening of the support plate and is fixed at least one place on the support plate and is arranged so as to have a slack portion thereafter.
The hub supporting portion, after through the loosened portions, so to support the intermediate conductive wire hub side, the wind turbine lightning current transmission system according to any one of claims 2 to 5. Before SL comprises a first element Ru annular member der that extends at least partially along the circumferential direction of the wind turbine blade, and a second element which is slidable brush in said annular member, according to claim 6 Windmill lightning current transmission system. The wind turbine blade is connected to the hub via a pitch bearing.
The lightning current transmission system for a wind turbine according to claim 6 or 7, wherein the first element and the second element are electrically insulated from the pitch bearing. The intermediate conductive wire is electrically connected to the conductive member via a second electrical connection portion.
The second electrical connection is
A third element connected to the intermediate conductive wire and supported by the hub,
A fourth element connected to the conductive member and supported by the nacelle,
The lightning current transmission system for a wind turbine according to any one of claims 1 to 8, comprising the above. One of the third element or the fourth element is an annular member extending at least partially along the circumferential direction of the main shaft of the wind turbine, and the other is a brush slidable on the annular member. Item 9. The lightning current transmission system for a wind turbine. One of the third element or the fourth element is an annular member extending at least partially along the circumferential direction of the main shaft of the wind turbine, and the other is a conductive member facing the annular member through a gap. The lightning current transmission system for a wind turbine according to claim 9, which is a unit. The hub is connected to the nacelle via a spindle bearing.
The lightning current transmission system for a wind turbine according to any one of claims 9 to 11, wherein the third element and the fourth element are electrically insulated from the spindle bearing. The lightning current transmission system for a wind turbine according to claim 12, wherein the spindle bearing includes an inner ring connected to the spindle connected to the hub and an outer ring connected to the nacelle. The second electrical connection portion according to any one of claims 9 to 12, wherein the third element and the fourth element are electrically connected at a plurality of positions along the circumferential direction of the main shaft of the wind turbine. Windmill lightning current transmission system. The lightning current transmission of the wind turbine according to any one of claims 1 to 14, wherein the intermediate conductive wire extends on the outer surface of the hub so as to partially surround the blade root portion of the wind turbine blade. system.

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