WIND POWER PLANT WITH LINEAR SYSTEM

Description

Technical field

[0001] The invention relates to a wind turbine with a busbar arrangement. Technical background

[0002] Wind turbines play a crucial role in the generation of renewable energy. A typical wind turbine consists of a nacelle mounted on a tower, which houses a generator connected to a wind turbine blade. To feed the electrical energy generated by the generator into a power grid, the generator is connected directly or indirectly to a power line installed within the wind turbine tower. A direct connection is possible in wind turbines with a gearbox, while in gearless wind turbines, a converter adapts the generator's output voltage to the grid frequency and phase, thus connecting the generator to the power line indirectly via the converter.

[0003] Space inside the gondola is naturally limited, and maintenance and installation work inside the gondola is complicated.

[0004] Against this background, the invention aims to introduce an improved wind turbine. A conductor rail arrangement with round spacers intended for use in a wind turbine is known from US 10,570,891 B2. Summary of the invention

[0005] The invention solves the problem by means of a wind turbine according to claim 1. Advantageous embodiments of the invention form the respective subject matter of the dependent claims.

[0006] The wind turbine according to the invention comprises a tower, a nacelle, and a wind turbine, the nacelle including a generator connected to the wind turbine. Furthermore, a busbar arrangement is provided, which connects an output of the generator to a conductor bundle arranged in the tower. The busbar arrangement has a plurality of busbars, each subdivided into individual busbar sections. The busbar sections are as shown in Fig. 6The invention shows a connection point connecting two adjacent busbar sections, which are electrically and mechanically connected. In each of the two busbar sections, two adjacent busbars are aligned parallel to each other within a busbar housing and are electrically and spatially separated from each other by an insulator disk located between the two busbars. The busbar arrangement also features active cooling, which is designed to move air through the busbar housing along a main flow direction. The insulator disk has a diameter that increases continuously along the main flow direction between an approach point of the insulator disk and a maximum diameter of the insulator disk. According to the invention, the maximum diameter of the insulator disk is larger than the diameter of the busbars.

[0007] Busbars are used in electrical installations to distribute electricity from a mains connection to loads within the installation, eliminating the need for free-running wiring. Busbars of various pre-assembled lengths can be used to adapt the distribution to the specific conditions of the installation. Busbar arrangements for distribution over longer distances can be divided into sections, each bridged by a set of busbars of the required length. At connection points between individual busbar sections, the busbars of each section are then overlapped, bringing the adjacent busbars into electrical contact.To distribute different current intensities, several busbars can be mounted in series and electrically connected in parallel to increase the conductor diameter. Insulating discs can be inserted at the connection points between the busbars, which serves both to improve cooling due to the spacing of the busbars and to provide electrical isolation between busbars on different electrical phases or potentials.

[0008] Due to the high currents carried by the busbars, these heat up, leading to thermal expansion of the busbars, which in turn causes mechanical stress on the busbar assembly. To carry the highest possible currents with constant conductor diameters and thus constant material usage, while simultaneously limiting the thermal expansion of the busbars, it is known to actively cool the busbars, for example, using fans.

[0009] The use of busbars for the electrical connection of a wind turbine generator to the conductor string in the tower is not yet known. For this connection, which is always the same length for a series of wind turbines and is also usually convoluted, pre-assembled cables have been used until now. The busbar arrangement provided according to the invention, however, is easier to install than a cable, even under the limited space conditions of a nacelle, and has the further advantage that the insulator discs, which are arranged at regular intervals at the connection points of the busbar sections and there restrict the flow channel for the cooling air, are flow-optimized so that the necessary insulator discs impair the flow resistance through the busbar housing as little as possible.In contrast to the square insulator disks commonly used in the prior art, which present one side of their square shape to the flow, the invention provides shapes with a continuously increasing diameter between the inlet point and the maximum diameter of the insulator disk. This shape allows for largely laminar flow around the insulator disk, enabling a higher volume flow rate than the turbulence of cooling air that inevitably occurs with angular shapes. Due to the reduced flow resistance and / or the increased volume flow rate, the busbars can be cooled more efficiently, resulting in a lower operating temperature for constant currents or the ability to carry higher currents for the same operating temperature. This allows the busbar to accommodate the relatively low generator voltages and high generator currents present over the short distance to the converter.The converter may have a transformer on the output side to transport power over the long distances through the tower and, if necessary, the wind farm at a higher voltage.

[0010] The diameter of the insulator disk is particularly advantageous if it is not only continuous but also smooth along the main flow direction between the point of inflow and the maximum diameter. This means that the mathematical derivative of the profile along the main flow direction is also continuous. This avoids edges in the profile, which further improves the laminar flow around the insulator disk.

[0011] For example, the insulator disc can have a circular circumference. Such an insulator disc can be mounted regardless of the main flow direction and, due to its rotationally symmetrical shape, always possesses the same advantageous flow characteristics.

[0012] Alternatively, the insulator disk can have a flow profile with a profile thickness and a profile chord, similar to that found, for example, on airfoils. The profile thickness is between 0.3 and 0.7 times the length of the profile chord. This means that the insulator disk has a smaller dimension perpendicular to the main flow direction than along the main flow direction. For example, the insulator disk can have a teardrop shape when viewed from the side.

[0013] The distance between opposing walls of the busbar housing, perpendicular to the main flow direction, is preferably at least 1.5 times the maximum diameter of the insulator disk. This ensures sufficient space between the walls and the nearest edge of the insulator disk for adequate airflow. However, this distance should not exceed twice the maximum diameter, as otherwise the busbar housing would become too large.

[0014] The busbar assembly can be equipped with a plurality of retaining elements, which are arranged directly or indirectly between the busbar housing and the plurality of busbars. The retaining elements are designed to hold the busbar housing at defined distances from the busbars. Each retaining element has at least one opening pointing in the main flow direction. The openings in the retaining elements allow the cooling air flowing through the busbar housing to pass through the retaining elements along the main flow direction, so that the flow of the cooling air is only minimally obstructed. Preferably, the openings in the retaining elements occupy at least half of the area encompassed by the retaining elements in the main flow direction.

[0015] Preferably, the active cooling of the busbar assembly comprises a plurality of air inlets and / or outlets distributed along the main flow direction. This makes it possible to release heated air from the busbar housing and supply cooler ambient air into the busbar housing. Furthermore, the distance over which the air flows through the busbar housing is shortened, which correspondingly reduces the flow resistance.

[0016] The active cooling system can comprise a plurality of fans distributed along the main flow direction. In principle, a fan can be arranged in any orientation, i.e., blowing air into or out of the busbar housing. For example, one fan can blow air in at an air inlet and another fan can draw air out at an air outlet. This also applies to embodiments according to the invention in which the active cooling system comprises a fan arranged in the inverter housing of a converter, and the busbar housing is fluidically connected to the fan arranged in the converter housing. The busbar arrangement connects the generator indirectly to the conductor train via the converter.This means that the active cooling fan does not have to be located directly on the busbar assembly, but can also be advantageously combined with other cooling systems for other components such as the inverter.

[0017] The busbar arrangement can be divided into several segments angled towards each other, with each segment comprising at least one busbar section. This allows the busbars to be routed in variable directions, simplifying installation in confined and angled spaces. Brief description of the images

[0018] The invention is explained in more detail below with reference to illustrations of exemplary embodiments. These show: Figure 1 a view of a conductor rail arrangement provided for a wind turbine according to the invention; Figure 2a top view of a first embodiment of an insulator disk as it can be used within the scope of the invention; Figure 3 a side view of the embodiment shown in Figure 2; Figure 4 a top view of a second embodiment of an insulator disk as it can be used within the scope of the invention; Figure 5 a partial view of busbars as they can be used for the busbar arrangement within the scope of the invention; Figure 6 a cross-section through a busbar assembly as it can be used within the scope of the invention; and Figure 7 a cross-section through an embodiment of a busbar arrangement for a wind turbine according to the invention. Detailed description of the illustrations

[0019] Figure 1Figure 1 shows a view of a busbar arrangement 1 provided for a wind turbine according to the invention, which in the example shown comprises three busbar sections 2 angled relative to each other. The actual busbars are not visible in the illustration, as they are arranged inside a busbar housing 3, which serves to insulate the busbars from the environment. Active cooling, in this case designed as a fan 4, which blows ambient air into the busbar housing 3 and directs it along a main flow direction 5 through the busbar housing 3, serves to cool the busbars so that they can carry a higher electrical current at the same temperature and expansion (see the relevant explanations above). Depending on the cooling requirements and the length of the busbar arrangement 1, fans 4 can be provided at both ends of the busbar housing and / or along the busbar arrangement 1.Likewise, multiple inlets and outlets for cooling air can be provided. It is also possible to fluidically connect the busbar housing 3 to a fan located in a converter of the wind turbine, so that the fan does not have to be provided on the busbar assembly itself, although a fan arranged in this way is considered part of the busbar assembly in this case.

[0020] Figure 2 Figure 1 shows a top view of a first embodiment of an insulator disk 6, as it can be used within the scope of the invention. The insulator disk 6 of Figure 2 It has a circular circumference. The insulator disk 6 is thus rotationally symmetrical about a hole 9 located in its center, so that the diameter of the insulator disk 6 increases continuously between a flow point 7 and a maximum diameter 8 along the main flow direction 5.

[0021] Around the hole 9, collars 10 are provided on both sides of the insulator disc 6, extending beyond the respective main extension planes of the respective side of the insulator disc 6. The collars 10 extend a cylindrical volume of the hole 9 and make it possible to electrically insulate a fastening element, such as a clamping bolt, passing through the hole 9 from busbars arranged on the sides of the insulator disc 6, thus allowing the fastening element to pass through one or more busbars without short-circuiting them.

[0022] Figure 3 shows a side view of the embodiment of the insulator disk 6 of Figure 2The illustrated embodiment has a stepped shape in the side view, in which a central area around the collars 10 serves as a bearing surface for the busbars and a thinner peripheral ring-shaped area serves to extend the creepage distance between opposing busbars resting on the insulator disk 6.

[0023] The thinner peripheral area of ​​the insulator disc 6 also offers lower flow resistance compared to a design in which the peripheral area has the same thickness as the central area of ​​the insulator disc 6, which serves as the contact surface for the busbars. A circular design of the insulator disc 6, as shown in the Figures 2 and 3The circular insulator disc 6 simplifies the assembly of the insulator disc 6, as it is not necessary to pay attention to the orientation of the insulator disc 6 relative to the main flow direction 5. However, the circular insulator disc 6 presents a higher flow resistance for cooling air guided through the busbar housing 3 than the embodiment of an insulator disc 6 shown below, as it can be used in the busbar arrangement according to the invention.

[0024] Figure 4Figure 1 shows a top view of a second embodiment of an insulator disk 6, which in this top view is shaped according to a flow profile, similar to those known from airfoils. However, according to the invention, it is advantageous to make the insulator disk 6 symmetrical about a profile chord line 11, since the flow profile is obviously not intended to generate lift. A profile thickness 12 is preferred, which in the example shown coincides with the maximum diameter 8 of the insulator disk 6, and is less than the profile chord line 11. For example, the profile thickness can be between 0.3 and 0.7 times the length of the profile chord line. In the example shown, the profile thickness 8 passes through the hole 9 of the insulator disk 6, but this is not necessary.

[0025] Figure 5Figure 1 shows a partial view of busbars 13 as they can be used for the busbar arrangement 1 within the scope of the invention. Two busbars 13, shown only partially, are electrically contacted over each other in a surface-to-surface manner, so that current can flow through the busbars 13. An insulator 6 is arranged between the busbars 13 and further busbars (adjacent busbars) located behind the busbars 13 shown in the view. In the example shown, this insulator is arranged according to the embodiment of the Figures 2 and 3 The conductor rail sections 2 of the conductor rail arrangement 1 are divided according to the individual conductor rails 13, which are oriented at an angle to each other in this case.

[0026] Figure 6 shows a cross-section through a busbar assembly as it can be used within the scope of the invention. The cross-section is in Figure 6at a junction point of two busbar sections 2. The example shown depicts a total of nine pairs of busbars 13 stacked on top of each other, whereby the two busbars 13 of each pair are in planar electrical contact with each other. In each pair of busbars 13, the busbars 13 point in at least approximately opposite directions, i.e., one busbar 13 points into the depth of the illustration and one points outwards.

[0027] In the example shown, three pairs of busbars 13 are provided for each of the three electrical phases. Of course, other numbers are possible, depending on the amount of electrical current to be carried, the cross-sectional area of ​​the busbars 13, the materials from which the busbars 13 are made, and the length of the busbar assembly or the maximum permissible resistance of the busbar assembly for a given application.

[0028] The busbars 13 of each pair are electrically and spatially separated from the adjacent busbars 13 by insulating discs 6. The busbars located furthest to the sides of the busbar assembly are also insulated laterally by insulating discs 6. The insulating discs 6 have a larger diameter than the busbars 13 in order to create increased creepage distances between adjacent busbar pairs.

[0029] The busbar assembly is held together by a clamping bolt 14, with spring elements 15 provided on both sides to exert a defined spring force on the superimposed busbars 13 and the insulator discs 6.

[0030] The clamping bolt 14 can also serve to attach a busbar housing (not shown) to the busbar assembly, which shields the busbars 13 from the environment. Alternatively, the busbar housing can be designed to be self-supporting, being supported or held only at the opposite ends of the busbar assembly and / or at support points distributed along the busbar assembly.

[0031] Cooling air can be directed through the busbar housing, with the cooling air shown in the cross-sectional drawing of the Figure 6at least approximately in or against a depth direction of the representation (main flow direction). While the cross-section in the example of the Figure 6 Due to the maximum diameters of the insulator discs 6, the flow points of the insulator discs 6 lie in a plane either in front of or behind the clamping bolt 14, depending on whether the main flow direction points in the direction of or against the depth direction shown in the illustration. Along the main flow direction, the insulator discs 6 have a diameter that increases continuously between the flow points of the insulator discs 6 and their maximum diameters.

[0032] The busbar housing can have opposing walls, preferably spaced apart from the insulator discs 6. The greater the distance, the greater the volume of cooling air that can be channeled through the busbar housing. The cooling capacity of the active cooling system increases with the volume of cooling air. However, the size of the busbar assembly is limited by the application. Therefore, the distance between the opposing walls of the busbar housing is preferably at least one and a half times the maximum diameter of the insulator discs 6 in one direction of spacing and perpendicular to the main flow direction. This leaves at least one-quarter of the maximum diameter of the insulator discs as free space at the junction of two busbar sections on each side of the busbar assembly.However, the distance between the opposing walls of the busbar housing should preferably not be more than twice the maximum diameter of the insulator discs in the spacing direction, as otherwise the busbar housing and the volume of the overall arrangement would become too large.

[0033] Figure 7 shows a cross-section through an exemplary embodiment of a busbar arrangement for a wind turbine according to the invention. The cross-section of the Figure 7 is located in the central area of ​​a conductor rail section, away from a connection to an adjacent conductor rail section, which is why the conductor rails 13 are not arranged in pairs as in Figure 6 but are to be seen individually spaced apart from one another. Insulators 16 are arranged between the busbars 13, which accordingly have at least approximately twice the thickness of the insulator discs 6. Figure 6Due to the increased creepage distances between adjacent busbars 13 caused by the greater thickness, the maximum circumference of the insulators 16 can be significantly smaller than that of the insulator discs 6 at the connections between adjacent busbar sections. In the example shown, the insulators 16 have annular ridges to increase the creepage distances. Depending on the application, the ridges can be enlarged, several ridges can be arranged side by side, or they can be omitted altogether.

[0034] The busbars 13 and insulators 6 are held by a bolt (not shown) guided through an axial opening in the insulators 6, the insulators 6 electrically isolating the bolt from the busbars 13. During transport and installation of the busbar assembly, the bolt can be used as a suspension point for lifting tools, cranes, rigging, and the like, so that the busbar housing 3 is not mechanically stressed by the weight of the busbars 13 inside it.

[0035] The busbar housing 3 can be held by retaining elements 17, which are also attached to the bolt, at defined distances from the sides and edges of the busbars 13. The retaining elements 17 of the exemplary embodiment of Figure 7The side walls of the busbar housing (shown on the left and right in the figure) maintain a lateral distance from the respective outermost busbars 13 of the busbar assembly. They also support the walls shown above and below in the figure, so that these are held at an advantageous distance from the edges of the busbars 13, as described above. The exemplary retaining elements 17 have openings or recesses 18 through which cooling air can pass in or against the depth direction of the illustration, i.e., in the main flow direction. This minimizes the obstruction of the cooling air flow through the busbar assembly by the retaining elements 17. To reduce the obstruction of the cooling air flow as much as possible, the openings 18 preferably occupy at least half of the area encompassed by the retaining elements 17 in the main flow direction.

[0036] The distances between the retaining elements 17 along the main flow direction of the cooling air can be half a meter or more, so that between the (in the Figure 7 (Staggered in depth direction) retaining elements 17 allow cooling air to flow freely along the side surfaces of the busbars 13.

[0037] The invention has been explained in more detail using exemplary embodiments. These examples serve to improve understanding and are not intended to limit the invention, which is defined exclusively by the following patent claims. Reference symbol list

[0038] 1 Busbar arrangement 2 Busbar section 3 Busbar housing 4 Active cooling 5 Main flow direction 6 Insulator disc 7 Inlet point 8 Maximum diameter 9 Hole 10 Collar 11 Profile chord 12 Profile thickness 13 Busbar 14 Clamping bolt 15 Spring element 16 Insulator 17 Retaining element 18 Opening

Claims

1. Wind power installation having a tower, a nacelle and a wind turbine, wherein the nacelle comprises a generator connected to the wind turbine, wherein a busbar arrangement (1) which connects an output of the generator to a line section arranged in the tower is also provided, wherein the busbar arrangement (1) comprises a plurality of busbars (13) divided into respective busbar portions (2), wherein two adjacent busbar portions (2) are connected at a connection point, whereby a respective busbar (13) of each of the two busbar portions (2) are in electrical contact, laid flat one on top of the other, at the connection point, wherein the respective busbars (13) of the two busbar portions (2) point at least approximately in opposite directions, wherein two adjacent busbars (13) of the same busbar portion (2) are aligned parallel to one another in a busbar housing (3) and are electrically and physically separated from one another by an insulator disc (6) arranged between the two busbars (13), a clamping bolt (14) which is designed to hold the busbars (13) together at the connection point, wherein spring elements (15) are provided on both sides of the clamping bolt (14) and are designed to exert a defined spring force on the busbars (13) lying one on top of the other and the insulator disc (6), and an active cooling system (4) which is designed to move air through the busbar housing (3) along a main flow direction (5), wherein the insulator disc (6) has a continuously increasing diameter along the main flow direction (5) between an inflow point (7) of the insulator disc (6) and a maximum diameter (8) of the insulator disc (6), wherein the maximum diameter (8) of the insulator disc (6) is greater than a diameter of the busbars (13).

2. Wind power installation of the preceding claim, in which the diameter of the insulator disc (6) runs evenly along the main flow direction (5) between the inflow point (7) and the maximum diameter (8).

3. Wind power installation of either of the preceding claims, in which the insulator disc (6) has a circular perimeter.

4. Wind power installation of either of Claims 1 and 2, in which the insulator disc (6) has a flow profile having a profile thickness (12) and a profile chord (11), wherein the profile thickness (12) is between 0.3 times and 0.7 times the length of the profile chord (11).

5. Wind power installation of one of the preceding claims, in which a distance between mutually opposite walls of the busbar housing (3), transversely with respect to the main flow direction (5), is at least 1.5 times the maximum diameter (8) of the insulator disc (6).

6. Wind power installation of one of the preceding claims, in which the busbar arrangement (1) is equipped with a plurality of holding elements (17) which are arranged directly or indirectly between the busbar housing (3) and the plurality of busbars (13) and are designed to hold the busbar housing (3) at defined distances from the busbars (13), wherein each holding element (17) has at least one through-hole (18) pointing in the main flow direction.

7. Wind power installation of one of the preceding claims, in which the active cooling system (4) comprises a plurality of air inlets and / or air outlets arranged distributed along the main flow direction (5).

8. Wind power installation of the preceding claim, in which the active cooling system (4) comprises a plurality of fans (4) arranged distributed along the main flow direction (5).

9. Wind power installation of one of Claims 1 to 7, in which the active cooling system (4) comprises a fan (4) arranged in a converter housing of a converter, wherein the busbar arrangement (1) connects the generator to the line section indirectly via the converter and wherein the busbar housing (3) is fluidically connected to the fan (4) arranged in the converter housing.

10. Wind power installation of one of the preceding claims, in which the busbar arrangement (1) is divided into a plurality of segments which are angled with respect to one another, wherein each segment comprises at least one busbar portion (2).