Pre-assembled bus bar module

Abstract

A pre-assembled bus bar module for mounting to a stator of a generator of a wind turbine, comprising: a plurality of bus bars spaced across an angle to be covered at the stator; a plurality of bus bar supporting devices, the bus bars are installed on the plurality of bus bar supporting devices, and the plurality of bus bar supporting devices are distributed on the angle interval; a mechanical interface for mounting the pre-assembled bus module to a mounting surface of the stator; and an electrical interface for electrically connecting the bus bar to a stator winding of the stator.

Description

TECHNICAL FIELD

[0001] The present invention relates to a pre-assembled busbar module for mounting to a stator of a generator of a wind turbine. BACKGROUND

[0002] Busbars are generally used for conducting large currents and typically comprise a metal bar or strip, the metal being for example copper. Busbars are used for transmitting and / or distributing large amounts of electrical power. One exemplary application is a wind turbine generator, wherein the busbars can be connected to the stator of the generator to transmit electrical power away from the generator.

[0003] The busbars have to be positioned in a specific arrangement with a specific distance to each other. This distance can depend on the voltage level, the cooling system, the size of the busbars and / or the space provided for the installation of the busbars. Therefore, busbar supports are used for mounting the busbars to a mounting surface and for positioning the busbars in this specific arrangement.

[0004] Busbar arrangements, especially for wind turbines, are known in the prior art. For example, EP 3 800 349 A1 discloses a busbar arrangement for a wind turbine generator, wherein the generator comprises a stator and a rotor arranged to rotate about an axis, wherein each busbar is arranged at a separate radial distance from the axis and at a separate axial position along the axis.

[0005] Another example of a busbar arrangement with several segments is described in WO 2020 / 108809 A1. This document discloses a stator for an electrical machine, in particular a generator of a wind turbine. The stator comprises a plurality of stator segments with several busbar segments connected to stator coils, wherein a segmented busbar is provided by connecting the busbar segments of adjacent stator segments belonging to the same phase using a segment connection mechanism. The segmented busbars of each phase are spaced apart from each other.

[0006] However, conventional busbar mounting is based on separate component mounting. The busbar support device and the busbars are positioned and mounted separately. Typically, the busbar support device is placed on a mounting surface and subsequently the busbars are stacked on top of each other, wherein the busbar supports of the busbar support device and the busbars are arranged continuously. The busbar support device needs to be adjusted in order to comply with the position requirements before the entire assembly is tightened. These production steps are very time consuming and are typically done at one production location, which leads to a reduced production flow. Due to the increased handling time, the existing series production for manufacturing wind turbine generators is negatively affected, in particular. SUMMARY

[0007] It is therefore an object of the present invention to provide a pre-assembled busbar module which improves the manufacturing of a wind turbine generator, in particular reduces the process time of the separate production processes, and improves the production flow.

[0008] This object is achieved by providing a pre-assembled busbar module for mounting to a stator of a generator of a wind turbine according to independent claim 1. Advantageous embodiments of the present invention are described in the dependent claims.

[0009] According to the present invention, a pre-assembled busbar module for mounting to a stator of a generator of a wind turbine is provided. The pre-assembled busbar module comprises: - a plurality of busbars spanning an angular interval to be covered at the stator; - a plurality of busbar support devices to which the busbars are mounted and which are distributed over the angular interval; - a mechanical interface for mounting the pre-assembled busbar module to a mounting surface of the stator; and - an electrical interface for electrically connecting the busbars to stator windings of the stator.

[0010] Thus, it is proposed to pre-assemble a busbar module which already comprises all busbars, their support and interfaces, thereby facilitating a quick and easy mounting on a support surface. By means of such a pre-assembled busbar module, the production of a wind turbine generator can be improved. The assembly of the busbar module and its mounting to a stator of a generator of a wind turbine can be performed in two separate production processes. The busbar module can be assembled in a first production process at a first production site. Then, the pre-assembled busbar module can be transported and mounted at the stator in a second production process at a second production site. Thus, the time-consuming assembly of the busbar module can be outsourced or performed at a production site different from the production site for mounting the pre-assembled busbar module to the stator. In this way, the production time of the second production process, i.e. the mounting, can be significantly reduced due to the less handling required. As a result, the production flow can be improved. In other words, the pre-assembled busbar module can be obtained from a supplier as a ready-to-mount module in order to avoid in-house production and the corresponding assembly.

[0011] The pre-assembled busbar module can be mounted to a stator or to a segment of a stator, respectively. In the following description, if it is referred to a mounting to a stator, it is to be understood that this also applies to a mounting to a stator segment.

[0012] The busbars of the pre-assembled busbar module are curved and can in particular be described as ring segments. The advantage of the curved shape of the busbars is that a plurality of pre-assembled busbar modules can be mounted to a stator, in particular to a respective stator segment, such that the modules form a ring following the typical ring shape of the stator.

[0013] The number of busbars in the pre-assembled busbar module can differ depending on the specific use case. For example, one busbar can be provided for each phase. The number of busbar support devices can differ depending on the size and weight of the busbars or the current transmitted by the busbars. In a preferred embodiment, the pre-assembled busbar module comprises three busbars and four busbar support devices evenly distributed over the angular interval of the busbars.

[0014] Preferably, the mechanical interface for mounting the pre-assembled busbar module to the stator is at least partially provided at one or more of the busbar support devices. Since the busbar support devices are used to position the busbars at a specific distance from each other, it is advantageous to also use the busbar support devices to provide the mechanical interface. Thus, the busbar support devices can be used for both positioning and mounting of the busbars. In this way, the busbar support devices provide a dual function and it is not necessary to provide a mechanical interface at the busbars, which can thus have a simple geometry compared to the busbar support devices.

[0015] In embodiments, the mechanical interface comprises a mounting mechanism for mounting the busbar support devices to a mounting surface. Such a mounting mechanism can be a bolt or a screw, which is driven into the mounting surface of the stator. Any type of component suitable for mounting the pre-assembled busbar module to the stator can be used as the mounting mechanism. Preferably, however, a mounting mechanism is used which is typically used for connecting multiple components.

[0016] In embodiments, at least one of the mounting mechanisms at least partially fixes multiple components of the busbar support devices together. By using a mounting mechanism which is not only used for mounting the pre-assembled busbar module to the stator but also for fixing multiple components of the busbar support devices together, the total number of mounting mechanisms and fastening mechanisms required can be reduced. This leads to a more efficient and simplified construction of the pre-assembled busbar module.

[0017] In preferred embodiments, each busbar support device comprises stackable busbar supports comprising a receiving section for each busbar, in particular for parallel extending busbars, for supporting the busbars. This allows the busbars to be arranged in a stacked manner along a stacking direction, wherein the busbar supports of the busbar support devices are positioned between the stacked busbars to provide the respective specific distance.

[0018] Each busbar support can advantageously comprise a receiving section for fixing the busbar. The receiving section can be referred to as a recess in the busbar support into which the busbar can be inserted, in particular slipped. After the second busbar support is stacked onto the busbar support with the first busbar, the first busbar is fixed by means of the two busbar supports compressing the first busbar and thus exerting a pressure force in the stacking direction. The receiving section of the busbar support can also serve as a fixing of the busbar in the radial direction, which refers to the angular interval covered by the curved busbar.

[0019] Preferably, the busbar support arrangement and thus the busbar support provides an insulation, in particular a rubber band or a polymer, to electrically insulate the busbars from each other and / or from the mounting surface. Additionally or alternatively, the busbar support arrangement and thus the busbar support can be made of an electrically insulating material, in particular EPG (Enhanced Protection Glass) or HGW (German: Hartgewebe) or a composite material comprising a resin matrix reinforced with glass fabric. Preferably, such a composite material has thermal, mechanical and electrical insulation properties which are sufficient for this particular application. The composite material can be manufactured by different methods, for example molding or lamination.

[0020] In an embodiment, the busbar support is fixed to the mounting plate, in particular between the mounting plate and the end plate, by means of a fastening member which is positioned laterally at the busbar support in the radial direction of the pre-assembled busbar module. The busbar support as well as the end plate and the mounting plate can comprise a through-hole which is positioned laterally at the busbar support, at the mounting plate and at the end plate. Preferably, the fastening member is a bolt or a screw which can extend through the through-hole and each busbar support arrangement can comprise two fastening members which, when tightened, fix the busbar by exerting a pressure force onto the busbar, in particular between the mounting plate and the end plate. In general, any type of fixing part can be used as a fastening member. However, a bolt is preferred.

[0021] In a further embodiment, each busbar support arrangement can comprise a first and a second fastening member, in particular a bolt, wherein the first fastening member fixes the end plate and the busbar support to the mounting plate, wherein the second fastening member also engages the mounting surface of the stator to fix the busbar support arrangement to the stator. Thus, the first fastening member is not used for any purpose of mounting the busbar support arrangement or even the pre-assembled busbar module to the mounting surface. The first fastening member can only fix the busbar support arrangement, in particular the mounting plate and the end plate as well as the busbar. However, the second fastening member can be one of the mounting mechanisms as it fixes the busbar support arrangement to the mounting surface of the stator.

[0022] As long as the pre-assembled busbar module is not mounted to the stator, the second fastening means cannot exert a pressure on the pre-assembled busbar module. Thus, the second fastening means cannot be used to fix the busbar support means and the busbar together. However, when mounting the pre-assembled busbar module to the stator, the second fastening means, which are preferably bolts, are driven into the mounting surface and exert a pressure to fix the busbar and the busbar support means, while also being used to mount the pre-assembled busbar module to the stator.

[0023] Thus, the mounting plate of each busbar support can comprise two lateral holes. One of these lateral holes can comprise an inner thread, such that the first fastening means can be fixed to the mounting plate, in particular by means of a threaded connection. However, the second of the lateral holes can be configured to allow the second fastening means to pass through the mounting plate, in order to provide a connection to the mounting surface on the side of the mounting plate opposite the busbar.

[0024] Each busbar support means can comprise one or more first and second fastening means. In any case, the mounting plate, the end plate and the busbar support need to provide a number of holes, the number of which corresponds to the number of first and second fastening means, wherein in the mounting plate one hole with an inner thread needs to be provided for each first fastening means and one through hole needs to be provided for each second fastening means.

[0025] As mentioned above, as long as the pre-assembled busbar module has not been mounted to the stator, it can not be firmly fixed. In order to avoid damaging the pre-assembled busbar module before the mounting process and / or to prevent the pre-assembled busbar module from being disassembled, an auxiliary fixing tool can be used. Thus, in a preferred embodiment, the pre-assembled busbar module comprises an auxiliary fixing tool, which is used to fix the components of each busbar support means together as long as the mounting mechanism has not been mounted. The auxiliary fixing tool can fix the pre-assembled busbar module when it fixes the components of each busbar support means together. Using the auxiliary fixing tool, only one bolt of each busbar support means can be sufficient to fix the respective end plate and the busbar support to the mounting plate.

[0026] Preferably, one auxiliary fixing tool can be provided for each busbar support means. Each auxiliary fixing tool can be fixed to the mounting plate of its respective busbar support means, such that the auxiliary fixing tool can easily be removed after mounting the pre-assembled busbar module to the stator. For example, the auxiliary fixing tool can be fixed to the mounting plate of its respective busbar support means using a screw. This fixing can be established by at least one bolt passing through the mounting plate, which bolt is essentially perpendicular to the mounting mechanism.

[0027] The auxiliary fixing tool preferably can provide at least essentially a U-shaped frame which serves as a clamp to exert a pressure between the mounting plate and the end plate of the respective busbar support device. In particular, the auxiliary fixing tool can comprise a fixing portion which is fixed to the mounting plate of the respective busbar support device and a plate which is fixed to the fixing portion by means of two connectors, in particular threaded rods with nuts. When fixed to the busbar support device, the plate can lie flat on the end plate of the busbar support device. In this way, the top plate and the mounting plate of the busbar support device can be pressed towards each other, thereby firmly holding the busbar and the busbar support between them. Since the auxiliary fixing device can be designed in a minimalistic way, it can be cheap and quickly manufactured.

[0028] In an advantageous embodiment, the busbar support device also supports a neutral conductor, in particular a neutral conductor which extends parallel to the busbar. Preferably, the electrical interface of the pre-assembled busbar module can comprise an additional connector for the neutral conductor. Providing such a neutral conductor can be advantageous, since the neutral conductor allows to divert a fault current from a generator which is separated from the busbar. In a preferred embodiment, the neutral conductor is electrically isolated or insulated from the busbar and the busbar support device. Thus, the neutral conductor can comprise an insulating top layer, for example a paint or a coating or an insulating tape. The neutral conductor can be glued or tied to the busbar support device. The neutral conductor can alternatively be fixed to the busbar support device by means of a form fit or a force fit.

[0029] In an embodiment, the electrical interface of the pre-assembled busbar module comprises electrical connectors which extend from the busbar and / or the neutral conductor to electrical contacts at a free end. The electrical contacts preferably have a flat surface for electrically connecting to the stator winding. All electrical contacts can be oriented such that the pre-assembled busbar module can be easily positioned on the mounting surface of the stator without collisions of the electrical contacts and the winding contacts of the stator. To achieve such a collision-free positioning, the electrical contacts can be oriented parallel or perpendicular to the mounting surface of the stator.

[0030] With the advantageous positioning and orientation of the electrical contacts, the electrical contacts are contactable or almost contactable with the winding connections of the stator after the pre-assembled busbar module is mounted (mechanical interface) to the mounting surface of the stator.

[0031] In a preferred embodiment, the electrical contacts are pre-soldered to the busbars. Each busbar can already comprise the plurality of electrical contacts required to connect the busbar to the winding contacts. In other words, the electrical contacts can be described as ready-to-solder contacts. This can be advantageous, because the electrical contacts are already connected to the busbars and thus do not need to be connected to the busbars during the installation process of the pre-assembled busbar module. However, the electrical contacts provide a surface for connecting the respective busbar to the respective winding contact by means of soldering or sintering. Thus, the installation process can be simplified, since the electrical contacts can already be arranged in a defined position on the busbar. This leads to an easy and fast installation, which reduces the process time of installing the pre-assembled busbar module to the stator and thus reduces the production flow. Since no additional soldering or sintering material is required, the required storage space can also be reduced.

[0032] Preferably, the electrical connectors are located in a section of the busbar which is not supported, in particular between the busbar support devices or at a side of the outer busbar support device. Thus, a collision of the busbar support devices or tools acting in the area of the busbar support devices or tools when pre-assembling the busbar module or installing the pre-assembled busbar module with the electrical contacts can be avoided. It can also be advantageous to position the electrical contacts with respect to the covered angular interval at a sufficient distance in the circumferential direction to provide an adjustment range for the busbar support devices in the circumferential direction.

[0033] In the radial direction, the electrical contacts are preferably only arranged on one side of the busbar, in particular on the radially outer side, with respect to the angular interval covered by the busbar.

[0034] In a further advantageous embodiment, the pre-assembled busbar module comprises at least one busbar interface, preferably two busbar interfaces, which are positioned transversely to the circumferential direction of the pre-assembled busbar module for mechanically and / or electrically connecting the busbar to the busbar of an adjacent pre-assembled busbar module and / or to the electrical connection device for the stator. The busbar interface allows the busbar of two or more pre-assembled busbar modules, in particular of such modules, to be coupled together or the busbar of one pre-assembled busbar module to be connected to the electrical connection device for the stator. The electrical connection device can be used to transmit the electrical power of the busbar away from the generator, for example by connecting one or more busbar interfaces having the electrical connection device to one or more conductors, preferably three conductors, of the wind turbine. In particular, the connection can be a connection to a power converter of the wind turbine.

[0035] The busbar interface enables the size of the pre-assembled busbar module, in particular the size of the angular interval to be covered at the stator, to be varied. Thus, depending on the specific requirements, the pre-assembled busbar module can be designed as a large or small module, wherein all modules can be interconnected by means of the busbar interface, independently of the number of modules.

[0036] Preferably, the surface of the busbar interface is electrically conductive, wherein the remaining part of each busbar comprises an electrical insulator, such as a coating or paint or an insulating tape layer. Thus, the electrical connection between two busbar interfaces or to a busbar interface can be achieved by means of mechanically connecting the two busbar interfaces or the non-insulated conductor and the busbar interface. If no sintering or welding material is required to strengthen the electrical connection, a bolt or a clamp can be sufficient to mechanically and electrically connect the two busbar interfaces or the connection device and the busbar interface. As already described for the preparation of soldered electrical contacts, this simplifies the installation process of the busbar module and can reduce the process time and the installation time.

[0037] To provide a firm mechanical connection between two busbar interfaces, each busbar interface can preferably comprise a plurality of openings, in particular four openings, wherein each opening is configured to receive a bolt. In other embodiments, the busbar interfaces of two pre-assembled busbar modules can be interconnected mechanically and electrically by means of a busbar connector, thereby bridging the gap between the two busbar interfaces. The busbar connector can be configured to provide a mechanically rigid connection between the busbar interfaces. Alternatively, the busbar connector can be movable or flexible to provide a connection that can be adapted to a given environment. For example, larger or smaller gaps can be bridged with the same busbar connector. The busbar connector can comprise a plurality of copper cables or similar insulated or non-insulated conductors.

[0038] In alternative embodiments, two busbar interfaces or one busbar interface and one electrical connection device can not be connected by means of a bolt, but by means of a clamp that exerts sufficient mechanical pressure to achieve a sufficient electrical and mechanical connection. However, the connection can alternatively be established by means of soldering or welding.

[0039] In a preferred embodiment, the pre-assembled busbar module comprises at least one auxiliary spacing tool that can be attached to the busbar interface, preferably by using a bolt, for maintaining the spacing of the busbar when the pre-assembled busbar module is not installed to the stator. Such an auxiliary spacing tool can be fixed to the circumferential end of the busbar of the pre-assembled busbar module that is configured as a busbar interface. In this way, the stability of the pre-assembled busbar module that is not installed can be further improved. With the same connection devices or methods already described for connecting two busbar interfaces or a busbar interface and a connection device, the auxiliary spacing tool can be fixed to the busbar interface.

[0040] Preferably, the auxiliary spacing tool can be reversibly attached to the busbar interface. Thus, the auxiliary spacing tool is not welded or soldered to the busbar interface. This is advantageous because the auxiliary spacing tool can simply be removed from the pre-assembled busbar module after the module has been installed to the installation surface of the stator.

[0041] The auxiliary spacing tools can be made of flat metal sheets which are welded, glued or screwed together.

[0042] The auxiliary spacing tools can further comprise one or more transport mounting means to be mounted to the transport vehicle and / or to the mounting surface of the stator. When the auxiliary spacing tools are attached to the pre-assembled busbar module, the transport mounting means can be oriented identically to the mounting means of the busbar support devices. Thus, for transport, by means of the mounting means of the pre-assembled busbar module and the transport mounting means of the auxiliary spacing tools, the pre-assembled busbar module and its attached auxiliary spacing tools can be mounted to the transport vehicle. Preferably, the pre-assembled busbar module further comprises an auxiliary fixation tool for each busbar support device. With the one or more auxiliary spacing tools and the auxiliary fixation tools in combination with the transport vehicle, the pre-assembled busbar module can be transported very securely, wherein movements of the busbars or the busbar support devices relative to each other can be prevented.

[0043] The pre-assembled busbar module can be installed using a method of installing a pre-assembled busbar module to a stator of a generator of a wind turbine, as explained below. The method comprises providing a pre-assembled busbar module with an auxiliary fixation tool fixed to each busbar support device and an auxiliary spacing tool fixed to each busbar interface of the pre-assembled busbar module. The auxiliary fixation tool and the auxiliary spacing tool are fixed to the pre-assembled busbar module, in particular by means of bolts.

[0044] Thereafter, the pre-assembled busbar module and its auxiliary fixation tools and auxiliary spacing tools are mounted to the stator by means of the mounting means and the transport mounting means, both of which are in particular bolts.

[0045] In a next step, the busbar support devices are additionally fixed to the stator by means of the second fastening members.

[0046] Finally, as the pre-assembled busbar module is now securely mounted to the stator, all auxiliary fixation tools and auxiliary spacing tools are detached from the pre-assembled busbar module. The electrical contacts of the busbar module and the windings of the stator are connected by means of brazing. The brazing can alternatively be performed before the auxiliary tools are detached.

[0047] The method can be performed using a pre-assembled busbar module comprising several auxiliary fixation tools and two auxiliary spacing tools with which the pre-assembled busbar module is mounted to a transport vehicle by means of mounting means and transport mounting means. For mounting the pre-assembled busbar module to a mounting surface of a stator, the transport vehicle needs to be detached from the pre-assembled busbar module before starting the mounting process according to the above-described method.

[0048] The method can utilize a pre-assembled busbar module having any of the configurations described herein. The above-mentioned advantages can also be achieved by the method according to the present application.

[0049] The present application also relates to a wind turbine having a generator with a stator, wherein at least one pre-assembled busbar module according to the present application is mounted to the stator.

[0050] It is to be understood that the features mentioned above and those to be explained below can be used not only in the specified combinations, but also in other combinations or in isolation, without departing from the scope of the present application. In particular, features of different aspects of the application can be combined with each other, unless stated otherwise. BRIEF DESCRIPTION OF DRAWINGS

[0051] Further objects and features of the present application will become apparent from the following detailed description, taken in conjunction with the accompanying drawings. However, the drawings are merely schematic and are therefore not to be considered limiting of the application. The drawings show: Figure 1 is a schematic view of a pre-assembled busbar module according to an embodiment; Figure 2 is a schematic cross-sectional view of the pre-assembled busbar module of Figure 1 Figure 3 is a schematic view of the back side of a mounting plate of a busbar support device; Figure 4 is a schematic view of a busbar support device according to an embodiment with an auxiliary fixing tool; Figure 5 is a schematic view of a pre-assembled busbar module according to an embodiment with an attached auxiliary spacing tool; Figure 6 is a schematic view of a pre-assembled busbar module with electrical connectors connected to stator windings; Figure 7 is a schematic view of a stator of a wind turbine generator with a plurality of pre-assembled busbar modules according to an embodiment; and Figure 8 shows a wind turbine according to the present application. DETAILED DESCRIPTION

[0052] Figure 1 An example of a pre-assembled busbar module 1 for mounting to a stator 2 of a generator of a wind turbine is schematically shown. The pre-assembled busbar module 1 comprises three busbars 3 which span an angular interval to be covered at the stator 2. The pre-assembled busbar module 1 further comprises four busbar support devices 4 supporting the busbars 3, wherein the busbar support devices 4 are equally distributed over the angular interval of the busbars 3.​

[0053] The pre-assembled busbar module 1 further comprises a mechanical interface 5 for mounting the pre-assembled busbar module 1 to a mounting surface 6 of the stator 2. The mechanical interface 5 is provided at the busbar support arrangement 4 and comprises mounting means 7, in particular bolts, to mount each busbar support arrangement 4 and busbar 3 to the mounting surface 6 of the stator 2. The busbar support arrangement 4 comprises several busbar supports 8 having receiving sections 9 configured to hold the busbar 3. An example of the busbar support arrangement 4 is illustrated in a cross-sectional view in Figure 2 .

[0054] In the following, further features of the exemplary pre-assembled busbar module 1 will be described with reference to Figures 2 to 6 . Figure 1 The coordinate system illustrates three directions (axial direction 200, circumferential direction 100 and radial direction 300) for a better understanding of the figures.

[0055] Figure 2 An example of a busbar support arrangement 4 according to the present application is illustrated. The busbar support arrangement 4 comprises a plurality of busbar supports 8 having receiving sections 9 stacked on top of each other along the axial direction 200. Furthermore, a mounting plate 10 and an end plate 11 are provided to which the busbar 3 and the busbar supports 8 are fixed by means of first fastening members 12 and second fastening members 13. The first fastening members 12 and the second fastening members 13 can be bolts.

[0056] Figure 2 The first fastening members 12 are exemplarily illustrated as rods having threaded end portions. Advantageously, the threads of the fastening members 12 do not touch the inner surfaces of the holes of the busbar supports 8. The threads of the first fastening members 12 are only provided on the portions of the members 12 that extend in the mounting plate 10 and on the portions of the members 12 that are located to the right of the end plate 11. The second fastening members 13 can be designed in the same way as the first fastening members 12 and only have threaded portions in the portions of the fastening members 13 that are driven into the stator 2 and that are located to the right (outside) of the end plate 11.

[0057] The first fastening members 12 fix the end plate 11 and the busbar supports 8 and the busbar 3 to the mounting plate 10, while the second fastening members 13 also engage the mounting surface 6 of the stator 2 to fix the busbar support arrangement 4 to the stator 2. Thus, the second fastening members 13 do not exert any pressure on the busbar support arrangement 4 in the axial direction 200 when the pre-assembled busbar module 1 is not mounted to the stator 2.

[0058] As Figure 1 and 2As shown, the second fastening element 13 serves as one of the mounting mechanisms 7 that fix the busbar support device 4 to the mounting surface 6. Advantageously, the second fastening element 13 not only fixes the busbar 3 and the busbar support device 4 in axial direction 200, but also serves as one of the mounting mechanisms 7. Due to the dual function of the second fastening element 13, less mounting mechanisms 7 are required and the number of required components of the pre-assembled busbar module 1 is reduced.

[0059] The busbars 3 are arranged parallel to each other in axial direction 200 and are held in receiving sections 9 of the busbar supports 8, which can be described as recesses arranged in the busbar supports 8. In the shown embodiment, the recesses of two busbar supports 8 form one receiving section 9. Alternatively, the receiving section 9 can be formed by the recess of only one busbar support 8 and a flat surface of a second busbar support 8 located on the opposite side in axial direction 200.

[0060] For a better understanding of the first and second fastening members 12, 13, Figure 3 A schematic view of the rear surface of the mounting plate 10 is shown, which comes into contact with the mounting surface 6 of the stator 2 when mounted onto the stator 2. The two mounting mechanisms 7 have already been shown in Figure 1 The mounting mechanisms 7 protrude from the mounting plate 10 and are driven into the mounting surface 6 of the stator 2. The fastening members 12 have already been shown in Figure 2 The fastening members 12 are screwed onto the mounting plate 10, but do not protrude from the mounting plate 10 in axial direction 200 opposite the busbars 3. Therefore, an inner thread is provided in the hole of the mounting plate 10 into which the first fastening members 12 are screwed. Finally, Figure 2 A left end of the second fastening member 13 is shown, which protrudes from the mounting plate 10 in axial direction 200 on the side opposite the busbars 3.

[0061] In an alternative embodiment, the busbar support device 4 can provide more than one first and / or second fastening member 12, 13. However, the number of holes of the mounting plate 10 and the holes with inner thread needs to be adapted to the respective number of first and second fastening members 12, 13. The number of holes in the busbar supports 8 and the end plate 11 needs to be adapted accordingly.

[0062] As long as the pre-assembled busbar module 1 is not mounted to the stator 2, the second fastening members 13 cannot be used to fix the busbar support device 4 and the busbars 3 together. Only the first fastening mechanisms 12 can be used for the fixation. To ensure the positioning of the busbars 3 relative to the busbar support device 4, an auxiliary tool is used.

[0063] Figure 4An example of an auxiliary fixation tool 14 is shown, which can be attached to the busbar support device 4 by means of two bolts 15, which fix a first part 16 of the auxiliary fixation tool 14 to the mounting plate 10 of the busbar support device 4. The auxiliary fixation tool 14 further comprises a second part 17, which is a u-shaped plate, wherein the first part 16 and the second part 17 are connected to each other by means of a screw rod 18. The u-shaped shape of the plate allows access to insert and fix the second fastening elements 13.

[0064] When attached to the mounting plate 10 of the busbar support device 4, the auxiliary fixation tool 14 can be used to exert a pressure, in particular in axial direction 200, to fix the top plate 11, the mounting plate 10 and the busbar support 8 as well as the busbars 3 (not shown) supported in the receiving sections 9 together. As the bolts 15 are oriented perpendicular to the mounting mechanism 7, the auxiliary fixation tool 14 can be detached from the mounting plate 10 and thus from the pre-assembled busbar module 1 after the pre-assembled busbar module 1 has been mounted to the stator 2. The first part 16 provides a stand which facilitates the detachment of the auxiliary fixation tool 14, in particular in radial direction 300. Figure 4

[0065] Before detaching the auxiliary fixation tool 14, the second fastening members 13 can be provided and driven into the mounting surface 6 of the stator 2 to fix the busbar support device 4 and the busbars 3 (not shown) to the stator 2. Thus, the u-shaped plate as second part 17 advantageously provides recesses 19 at the end plate 11 and thus free space for mounting the second fastening members 13.

[0066] Referring back to Figure 1 , the pre-assembled busbar module 1 further comprises two busbar interfaces 20, which are positioned laterally in circumferential direction 100. At each busbar interface 20, the busbar 3 is not electrically conductive, thus not insulated, and comprises four holes 21, which are used to mechanically connect the busbar 3 to the busbar 3 of an adjacent busbar module 1 or to an electrical connection device of the stator 2. As the busbar 3 is not isolated at the busbar interface 20, an electrical connection can be achieved by mechanical contact. Thus, bolts and nuts can be used with the holes 21 to connect two adjacent busbar interfaces 20 or one busbar interface 20 and an electrical connection device. Other connectors, such as clamps, can be used instead of bolts and nuts.

[0067] As long as the pre-assembled busbar module 1 is not mounted to the stator 2, the busbar interfaces 20 can be used to hold the pre-assembled busbars 3 in place. In this embodiment, an auxiliary spacing tool 22 is used to fix the busbar interfaces 20, thus the end sections of each busbar 3, to maintain the spacing between the busbars 3. One example of such an auxiliary spacing tool 22 is shown in Figure 5 ​A further embodiment of the pre-assembled busbar module 1 is shown in Fig. 2. In this embodiment, the auxiliary spacing means 22 comprises a plurality of metal plates which fix the end portions of the busbar 3. The auxiliary spacing means 22 further comprises a transport mounting mechanism 23 which is mountable to a transport vehicle (not shown) or to the mounting surface 6 of the stator 2. As Figure 5 shown, the transport mounting mechanism 23 is preferably a bolt.

[0068] In order to achieve a reliable transport of the pre-assembled busbar module 1, one auxiliary spacing means 22 is attached on each of the two busbar interfaces 20. The pre-assembled busbar module 1 and the auxiliary spacing means 22 are then mounted to the transport vehicle by means of the mounting mechanism 7 and the transport mounting mechanism 23. In addition, the aforementioned auxiliary fixing means 14 are attached to the mounting plate 10 of each busbar support device 4. In this way, the pre-assembled busbar module 1 is supported and can be reliably transported. By means of the auxiliary spacing means 22 and the auxiliary fixing means 14 and the transport vehicle (not shown), unwanted movements of the busbar 3 or the busbar support devices 4 are prevented.

[0069] In order to enable a current flow from the generator, in particular from the windings of the stator 2, the pre-assembled busbar module 1 shown in Figure 1 Fig. 2 further comprises an electrical interface 24. With this electrical interface 24, the busbar 3 of the pre-assembled busbar module 1 can be electrically connected to the stator windings 28 of the stator 2 (cf. Fig. 3). Figure 6 The pre-assembled busbar module 1 further comprises a neutral conductor 25 which extends parallel to the busbar 3. With the neutral conductor 25, an unbalanced voltage generated by the generator or the power converter can be measured during testing. The neutral conductor 25 is glued or tied to the busbar support devices 4 and is electrically isolated from the busbar 3 and the busbar support devices 4.

[0070] In order to establish an electrical connection between the busbar 3 and the stator windings 28 and between the neutral conductor 25 and the stator windings 28, the electrical interface 24 comprises electrical connectors 26 which extend from the busbar 3 and the neutral conductor 25 to electrical contacts on the free end 27. In Figure 6 Fig. 3, an example of the electrical connection of the stator windings 28 to the electrical connectors 26 is shown.

[0071] The free end 27 of the electrical connectors 26 is soldered to the stator windings 28 to provide electrical contact and to transport electrical power away from the stator windings 28.

[0072] The electrical contacts 26 are oriented such that they contact or almost contact the stator windings 28 when the pre-assembled busbar module 1 is mounted to the stator 2. Thus, there is an overlap of the electrical connectors 26, in particular of the free end 27 of the electrical connectors 26, and the stator windings 28 when the pre-assembled busbar module 1 is mounted to the stator 2. Since the electrical contacts 26 are already provided on the busbar 3, a faster mounting can be achieved and thus a reduced handling time and an increased production flow.

[0073] As Figure 1 and Figure 6 shown, the electrical connectors 26 are located in the unsupported portion of the busbar 3, in particular between the busbar supports 4. In this way, there is sufficient space in the circumferential direction 100 to position the busbar support devices 4 as desired.

[0074] Figure 7 An exemplary view of a generator 29 with a stator 2 comprising six stator segments 30 is shown, wherein three of the six stator segments 30 each form a winding system capable of generating electrical power independently. One busbar system 41, 42 is connected to one of the two winding systems of the stator 2, wherein one preassembled busbar module 1 is mounted to each stator segment 30. All preassembled busbar modules 1 comprise two busbar interfaces 20 (not shown), wherein the busbar interfaces 20 of two adjacent preassembled busbar modules 1 of one busbar system 41, 42 are electrically and mechanically connected by means of a busbar connector 31. In other embodiments, the busbar interfaces 20 of the segments can also be at least partially connected to a corresponding connection device 32, thereby allowing each stator segment 30 to generate electrical power independently of the other stator segments 30.

[0075] Such a busbar connector 31 can comprise one busbar segment, in particular an arcuate busbar segment, which is designed to be bolted or clamped or welded to the end portions of the two busbars 3 of the adjacent busbar interfaces 20 in the circumferential direction 100. Alternatively, the busbar connector 31 can be a copper cable, in particular with a clamp, to connect the end segments of the two busbars 3 adjacent in the circumferential direction 100. However, the busbar connector 31 can be a braided copper wire tape. Each busbar interface 20 comprises a plurality of busbar end segments, the number of which corresponds to the number of busbars 3 in the corresponding preassembled busbar module 1. The busbar end segments of two adjacent preassembled busbar modules 1 are connected such that one busbar 3 of one preassembled busbar module 1 is connected to only one busbar 3 of its adjacent preassembled busbar module 1. However, the busbar interfaces 20 of two adjacent preassembled busbar modules can be connected without the use of a busbar connector 31. The adjacent busbar interfaces 20 can be bolted or screwed together using only the holes 21 of the busbar interfaces 20.

[0076] The preassembled busbar modules 1 of each busbar system 41, 42 are interconnected by means of the busbar connectors 31. Thus, the angular intervals of the respective busbars 3 are connected to form a larger continuous busbar, wherein in each busbar system 41, 42 the number of continuous busbars corresponds to the number of busbars 3 in one preassembled busbar module 1.

[0077] The neutral conductor 25 ( Figure 7(Not shown) are connected such that each stator segment 30 has its own neutral conductor 25. The neutral conductor 25 is connected only to the stator winding 28. Therefore, unlike bus 3, the neutral conductors 25 of the multiple pre-assembled bus modules 1 are not interconnected.

[0078] exist Figure 7 In the purely illustrative example shown, one bus interface 20 of each bus system 41, 42's two pre-assembled bus modules 1 is electrically connected and mechanically connected to the electrical connection device 32 of the stator 2. Through the electrical connection device 32, power transmitted from the bus 3 is carried away from the bus 3 using separate conductors 33, each conductor 33 carrying current from one of the bus 3. Alternatively, as described above, each stator section 30 may have its own one or more pre-assembled bus modules 1, with each pre-assembled bus module's own connection device 32 operating independently of the other stator sections 30 or groups of stator sections.

[0079] When pre-assembled busbar modules 1 are installed onto stator 2, the busbar interfaces 20 of two adjacent pre-assembled busbar modules 1 may not be in contact with each other. A gap may exist between two adjacent busbar interfaces 20 along the circumferential direction 100. A busbar connector 31 can be used to bridge such gaps and provide both mechanical and electrical connections between two adjacent busbar interfaces 20 (i.e., adjacent ends of the busbar 3). In other embodiments, the busbar connector 31 may be flexible (e.g., copper cable) or extendable to provide electrical connections between two adjacent busbar interfaces 20, but not rigid mechanical connections. This can be advantageous because one type of busbar connector 31 can be used for pre-assembled busbar modules 1 of different sizes.

[0080] Figure 8 A wind turbine 35 according to the present invention is shown. The wind turbine 35 includes blades 36 mounted on a rotor hub 37, which is connected to a rotor 38 of a generator 29 having a stator 2. The generator 29 is housed in a nacelle 39 supported by a tower 40.

[0081] Although the present invention has been described in detail with reference to preferred embodiments, the invention is not limited to the disclosed examples, and those skilled in the art can derive other variations from the examples without departing from the scope of the invention.

[0082] Individuals who are male or female are included in the terminology, independent of grammatical usage.

Claims

1. A pre-assembled busbar module (1) for mounting to a stator (2) of a generator (29) of a wind turbine, comprising: - a plurality of busbars (3) spanning an angular interval to be covered at the stator (2); - a plurality of busbar support devices (4) to which the busbars (3) are mounted and which are distributed over the angular interval; - a mechanical interface (5) for mounting the pre-assembled busbar module (1) to a mounting surface (6) of the stator (2); and - an electrical interface (24) for electrically connecting the busbars (3) to stator windings (28) of the stator (2).

2. The pre-assembled busbar module (1) according to claim 1, characterized in that the mechanical interface (5) is at least partially provided at one or more of the busbar support devices (4).

3. The pre-assembled busbar module (1) according to claim 1 or 2, characterized in that the mechanical interface (5) comprises a mounting mechanism (7) for mounting a busbar support device (4) to the mounting surface (6).

4. The pre-assembled busbar module (1) according to claim 3, characterized in that at least one mounting mechanism (7) further at least partially fixes a plurality of components (8, 10, 11) of a busbar support device (4) together.

5. The pre-assembled busbar module (1) according to claim 4, characterized in that the pre-assembled busbar module (1) comprises an auxiliary fixation means (14) for fixing the components (8, 10, 11) of each busbar support device (4) together as long as the mounting mechanism (7) has not been mounted.

6. The pre-assembled busbar module (1) according to any of the preceding claims, characterized in that each busbar support device (4) comprises a stackable busbar support (8) comprising a receiving section (9) for each busbar (3), in particular a parallel extending busbar, for supporting the busbar (3).

7. The pre-assembled busbar module (1) according to claim 6, characterized in that the busbar support (8) is fixed to a mounting plate (10), in particular between the mounting plate (10) and an end plate (11), by means of a fastening member (12, 13) which is positioned laterally at the busbar support (8) in a radial direction (300) of the pre-assembled busbar module (1).

8. The pre-assembled busbar module (1) according to claim 7, characterized in that each busbar support device (4) comprises a first and a second fastening member (12, 13), in particular a bolt, wherein the first fastening member (12) fixes the end plate (11) and the busbar support (8) to the mounting plate (10), wherein the second fastening member (13) further engages the mounting surface (6) of the stator (2) to fix the busbar support device (4) to the stator (2).

9. The pre-assembled busbar module (1) according to any of the preceding claims, characterized in that The busbar support device (4) also supports a neutral conductor (25), in particular a neutral conductor which extends parallel to the busbar (3).

10. The pre-assembled busbar module (1) according to any one of the preceding claims, characterized in that The electrical interface (24) comprises an electrical connector (26) which extends from the busbar (3) and / or the neutral conductor (25) to an electrical contact at the free end (25).

11. The pre-assembled busbar module (1) according to claim 10, characterized in that The electrical contact is located in a section of the busbar (3) which is not supported, in particular between busbar support devices (4), or at one side of an external busbar support device (4).

12. The pre-assembled busbar module (1) according to any one of the preceding claims, characterized in that The pre-assembled busbar module (1) comprises at least one busbar interface (20), preferably two busbar interfaces (20), which are positioned transversely to the circumferential direction (100) of the pre-assembled busbar module (1) for mechanically and / or electrically connecting the busbar to the busbar (3) of an adjacent pre-assembled busbar module (1) and / or for the electrical connection device (32) of the stator (2).

13. The pre-assembled busbar module (1) according to claim 12, characterized in that The pre-assembled busbar module (1) comprises at least one auxiliary spacing tool (22) which can be attached to the busbar interface (20), preferably by using a bolt, for maintaining the spacing of the busbar (3) when the pre-assembled busbar module (1) is not installed to the stator (2).

14. The pre-assembled busbar module (1) according to claim 13, characterized in that The auxiliary spacing tool (22) comprises a transport mounting mechanism (23) which is to be mounted to a transport vehicle and / or to a mounting surface (6) of the stator (2).

15. A wind turbine (35) comprising a generator (29) having a stator (2), wherein At least one pre-assembled busbar module (1) according to any one of the preceding claims is installed to the stator (2).

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