Multifunctional electrical busbar

Abstract

An electrical busbar comprises a first and second terminals and supports conductance of an electric current between them. The electrical busbar is at least partly manufactured by additive manufacturing to comprise at least one auxiliary function region, for example one or more of a heat transfer region, an electrically insulated region, a flexible region, a mechanical support region, a mounting region, a flow guiding region, a reduced material region, or combinations thereof. An electrical system comprises electrical components connected to electrical conductors, of which one or more are the electrical busbar having auxiliary function regions.

Description

MULTIFUNCTIONAL ELECTRICAL BUSBARField of the invention

[0001] The present invention relates to an electrical busbar with an auxiliary function region formed by additive manufacturing.Background of the invention

[0002] Electrical busbars typically comprise a rectangular block, bar or rail of solid copper for conducting a high current in a high-power electrical system. Bolt holes may be drilled for connection and mounting points, and simple bends may be applied, but apart from this, busbars offer no additional features. Also, the heavy, rigid and solid busbars are challenging to work with in connection with installation and maintenance, requiring supplementing numerous additional items like bolts, insulation, heat fins, flexible shunts, etc., to achieve required or desired functionality, or simply to be able to mount the busbar in an electrical system. Flexible busbars exist in the form of braided or laminated copper strands. However, while being flexible with respect to their physical geometry, such busbars are even less flexible with respect to mounting or other requirements, as they cannot simply be drilled, cut, insulated, mounted, etc.Summary of the invention

[0003] The inventors have identified the above-mentioned problems and challenges related to busbar requirements besides current conductance, and subsequently made the below-described invention which improve busbars to better facilitate or comply with desires or requirements, without hindering the main purpose of conducting high currents.

[0004] The invention relates to an electrical busbar comprising at least one first terminal and at least one second terminal and being configured to support conductance of an electric current between said at least one first terminal and said at least one second terminal, wherein said electrical busbar is at least partly manufactured by additive manufacturing to comprise at least one auxiliary function region.

[0005] Besides the main purpose of an electrical busbar to support conductance of current between at least two terminals, the present invention advantageously provides for further auxiliary functions of the busbar created by means of additive manufacturing, also referred to as 3D-printing. The entire busbar, or portions thereof, may be 3D-printed. Usually, a busbar is formed by an elongated solid block of copper or aluminum, or by braided or laminated copper strands where flexibility is required. Additive manufacturing according to the invention can further significantly improve the flexibility options and achieve further auxiliary functions as described herein.

[0006] By electrical busbar is understood a component for electrical distribution in a system, e.g. in an electrical cabinet, including main busbars mounted along a top, back, side or bottom of a cabinet, or transition busbars, connecting busbars, shunts, etc., connecting electrical components or other busbars with the main busbars, in- or out- feed cables, etc.

[0007] As described in more detail below, possible advantageous auxiliary functions of the auxiliary function region may comprise one or more of improved heat transfer, electrical insulation, flexibility, mechanical support or mounting options, cooling fluid flow guiding, reduced material consumption and weight, etc. Preferably, the auxiliary function region, at least when placed in the current conductance path between the first and second terminals, should maintain electrical properties at least corresponding to the normal busbar it replaces and / or at least corresponding to the requirements of the system it forms part of.

[0008] All or part of the electrical busbar, at last in connection with the auxiliary function region, is manufactured by additive manufacturing, also popularly referred to as 3D printing. Such manufacturing process may be based on, but not limited to, one of the following additive manufacturing processes: 3D printing, layer by layer printing, Wire Arc Additive Manufacturing, Fused Deposition Modeling FDM, Direct Energy Deposition, Direct Metal Deposition, sintering based processes, laser based processes such as selective laser melting SLM or selective laser sintering SLS, cold spray additive manufacturing CSAM, etc. The particular additive manufacturing technology to utilize may be selected based on the requirements for materials, such as copper,aluminum or alloys for conductors and various plastics or plastic-like materials for insulators, as well as based on the desired extend of the busbar, manufacturing precision, specific auxiliary functions, etc.

[0009] In an embodiment said at least one auxiliary function region comprises one or more from the list of a heat transfer region, an electrically insulated region, a flexible region, a mechanical support region, a mounting region, a flow guiding region, a reduced material region, or combinations thereof.

[0010] In particular when combining several of the mentioned auxiliary function regions with the main purpose of current conductance, a highly advantageous electrical busbar may be provided. The various kinds of regions mentioned will be described and exemplified in more detail below.

[0011] In an embodiment said at least one auxiliary function region comprises a heat transfer region comprising at least one internal cooling fluid channel.

[0012] By heat transfer region is understood a segment, surface area or otherwise part of the electric busbar, which is designed with improved heat transfer capabilities compared to a traditional solid metal block busbar. A heat transfer region may preferably comprise surface increasing features and / or cooling fluid channels, such as cooling fins, branched conductors, web-like, bionic or other ‘airy’ geometries, cooling channels, etc. In some embodiments, the heat transfer region may comprise a different material than the rest of the electrical busbar The heat transfer region may advantageously facilitate better heat dissipation to the surrounding air or cooling fluid, most efficiently by increasing the surface area or by integrated cooling channels, and may be arranged for passive or active cooling systems.

[0013] In an embodiment said heat transfer region comprises at least one integrated heat sink.

[0014] An integrated heat sink may be advantageous in that not only may it improve cooling of the electrical busbar itself, e.g. when used as a high-power busbar for conducting currents to or from a component to which it is connected. But suchintegrated heatsink advantageously also enables cooling of a connected electrical component such as a power electronic component such as a power module by mounting the power modules with a thermal connection to the busbar with an integrated heat sink. Thereby eliminating or reducing the need of separate heat sinks for the power module.

[0015] The heat sink may provide a larger surface area of the busbar where it is located compared to other parts of the busbar where no heat sink is located. In addition, or alternatively a heat sink may provide a more open surface of the busbar, also referred to as ‘airy design’, particularly of the heat transfer region, compared to portions of the busbar which have no heat sink.

[0016] It should be mentioned that a heat sink may be made of two or more materials and thus the busbar and the heat sink could be referred to as polylithic. Hence, despite two materials a polylithic busbar with heat sink is still composed of the two materials without joints or seams.

[0017] In an embodiment said at least one heat sink is removably attached to said electrical busbar at said heat transfer region.

[0018] Thereby it may be possible to adjust the position of the heat sink on the busbar. Thus, it is possible to adjust heat sink capacity directly to a hot spot e.g. of an electrical component or an area which need cooling by airflow. In fact, it may be possible during operation of an electrical system to establish a thermography of the electrical system and based on an evaluation of the resulting picture adjust or position one or more heat sinks to increase cooling at relevant areas.

[0019] In an embodiment said at least one heat sink is an integrated part of said electrical busbar at said heat transfer region.

[0020] Thereby no additional components may be needed to remove heat from a heat generating component.

[0021] In an embodiment said electrical busbar comprises integrated fan fastening points at said heat transfer region.

[0022] Thereby a fan may be mounted directly to the electrical busbar, preferably directly above an integrated heat sink e.g. of a middle part of the electrical busbar between the terminals. Thus, a flow of cooling air may be generated by a fan directly towards the heat sink of the electrical busbar, towards an additional heat sink, towards an electrical component, etc.

[0023] In an embodiment said integrated heat sink is formed by an electrically conductive material of a middle segment of said busbar at said heat transfer region.

[0024] This is advantageous in that the electrical busbar itself becomes a heat transferring heat sink. The middle part of the electrical busbar thereby has a dual purpose of transferring heat from a component and conducting current to or from a component.

[0025] In an embodiment said integrated heat sink forms part of said electrical busbar at said heat transfer region, and wherein said integrated heat sink is at least partly manufactured with an air penetrating geometry, for example by comprising a plurality of conductor branches having airgaps between them.

[0026] An air penetrating geometry is advantageous in that a flow of cooling fluid such as air is allowed to flow between conductor branches of the heat transfer region of the busbar. Thereby is obtained a better transfer of heat from the individual conductor branches and for example from a heat generating component connected to it. The air penetrating geometry may be selected from the list comprising: gyroid-like design, branch-like design, bionic design, web-like design, honeycomb design and spongy design. Such designs may be advantageous in that a cooling air flow is able to enclose the electrical busbar. Further, these designs may comprise or be designed with air guides for guiding the cooling air flow towards a desired hot spot of a heat generating component air. In this way heat may be effectively removed from large areas surrounding the electrical busbar.

[0027] In an embodiment said first terminal is comprised by a first end and second terminal is comprised by a second end, and wherein said heat transfer region with said heat sink is integrated in said first end and / or in said second end.

[0028] Having a heat sink at the surface of the ends of the electrical busbar is advantageous in that heat generated at the connection between the terminals of the busbar and an electrical component to which it is connected can be removed. In this and similar situations, an integrated heat sink is advantageous over known ways of removing heat such as simple extending the ends of the busbar to establish more area of the busbar. By the heat sink of the present embodiment, the same heat dissipating areas or even larger areas can be provided with less material and at the same time without compromising the free space needed for mounting the electrical busbar to the electrical component.

[0029] In an embodiment said middle segment of said busbar with said integrated heat sink is manufactured as one monolithic geometry by additive manufacturing.

[0030] A monolithic geometry is advantageous in that the middle segment including an integrated heat sink as a heat transfer region is manufactured in one piece. The additive manufacturing allows for a high degree of freedom in designing a part of the busbar with the auxiliary function of a heat transfer region.

[0031] In an embodiment said monolithic geometry comprises one or more protrusions or one or more recesses, such as one or more outgrowing cooling fins.

[0032] Protrusions / outgrowths are advantageous in that they increase the area of the electrical busbar where a flow of cooling fluid is able to remove heat. More specifically, the area is increased by using a minimum of material.

[0033] In an embodiment said heat transfer region is thermally connected with a heat generating electrical component wherein a physical location of said thermal connection at said electrical component is different from a physical location of an electrical connection from said electrical component to an electrical busbar, such as said busbar.

[0034] This is advantageous in that it has the effect that heat can be transferred from the component to the heat transfer region of the busbar and thus to the ambient via the heat sink. More specifically, heat may be removed from the component at a locationof the component that is different from the location where the busbar is electrically connected to the component. This is also true if the busbar comprising the heat sink is also the busbar which is electrically connected to the component.

[0035] In an embodiment said heat transfer region is connected directly to said heat generating electrical component.

[0036] This is possible if the busbar with the heat sink is also supplying the electrical component, or vice versa. This is advantageous in that no additional components are needed to also achieve the heat transfer auxiliary function. With this said a thermal conductive paste may be used to ensure that no air pockets are present in the thermal path between heat sink of busbar and component. The busbar may be fastened to the component with screws, adhesives, cold spray, etc.

[0037] A thermal connection to the heat transfer region from a heat generating electrical component may be highly advantageous to achieve a dual function of supplying power to the electrical component and removing heat from the electrical component. Doing the latter via an integrated heat sink as described, may significantly improve the heat handling compared to known electrical busbars with no means for removing heat other than their planar surfaces which are not optimized for heat removal.

[0038] An additional heat sink may also be inserted between the electrical component and the heat transfer region of the electrical busbar and achieve the effect that a minimum distance between the component and the busbar can be ensured. This minimum distance may be a requirement form the producer of the electrical component to protect electronics, switches, etc. in the component. The additional heat sink may be screwed to the heat transfer region of the busbar and to the component, or it may be fastened by a pivotable clamp fixed to the additional heat sink or the busbar and secured on the component. The additional heat sink is preferably is at least partly manufactured from an electrically insulating material, to further provide galvanic isolation between the heat transfer region of the busbar, and the thermal connection point of the electrical component. As an example, the additional heat sink may be of aceramic material, plastic / polymer, etc. Thus, the additional heat sink may guide a flow of air so that the air flow is passing by e.g. a backplate of the electrical busbar and passing by the integrated heat sink of the electrical busbar. The flow may be generated by a fan that may be positioned / connected to the additional heat sink or the electrical busbar. Heat sinks in the form of protrusions or outgrowths are advantageous in that in addition to guiding heat away from the busbar, they may also be used for guiding a flow of air in a predetermined direction.

[0039] In an embodiment said heat transfer region with integrated heat sink is located in an electrical cabinet at a location of a cold spot.

[0040] A cold spot should be understood as a location inside an electrical cabinet where a flow of cooling air is higher than other locations. A cold spot could be established by installing air guides strategic inside the electrical cabinet and thereby guide a flow of air, which may be provided by a fan, towards one side, middle section or the like. Hence, in such cold spot it may be advantageous to locate a heat sink of an electrical busbar due to the high flow of cooling fluid such as cooling air.

[0041] In an embodiment said heat transfer region with integrated heat sink is located in an electrical cabinet at a location of a hot spot.

[0042] A hot spot should be understood as a location inside an electrical cabinet where more heat is generated than other locations. A hot spot is typically at an electrical component such as a busbar, a power module, a reactor, etc. It is advantageous to connect a part, such as the heat transfer region comprising a heat sink, thermally to such heat generating electrical component. Thermally connection may be understood as a direct connection between the integrated heat sink and the heat generating component, a connection via a thermal paste, via an additional heat sink, or the like.

[0043] In an embodiment said heat transfer region comprises at least one internal cooling fluid channel.

[0044] Providing an internal cooling fluid channel in the heat transfer region of the busbar allows for circulating a cooling fluid, such as a liquid coolant or gaseous coolant, such as air. A liquid coolant may, e.g., be selected as a type of oil which may be non-electrical conductive and thereby work as both cooling fluid and isolator. Other liquid coolant may comprise water, deionized water, Glycol, liquid, metal such as Gallium, mercury, etc. An attached cooling system may circulate the cooling fluid in a temperature regulation loop, which in this case may be referred to as a cooling loop, with a flow speed in the range of 4L / min to lOL / min per power module. Therefore, the cooling system should be able to provide a flow of cooling fluid in the range of 48L / min to 120L / min in electrical systems having parallel power modules on each of three phases (12 power modules x 4-10L7min). The temperature of the cooling fluid is preferably below 55°C in that it is often desired to maintain a temperature below 55°C in the high-power electric system.

[0045] The internal cooling channel may be configured to guide a cooling fluid through the busbar, such as a high-power busbar, at the heat transfer region. In this way, the temperature of the high-power busbar, especially around the internal cooling channel, can be reduced. Sufficient cooling via the internal cooling channel may lead to an increase in the current capacity of the busbar, e.g. in relation to a power module and / or handled by a power module. This is because temperature is then no longer as limiting a factor compared to power modules of known electric system only cooled by an air flow on the outside of the busbar.

[0046] The cooling system of the temperature regulation system may include a heat pump, heat exchanger or similar for facilitating a temperature decrease of the cooling fluid circulated in the internal channel.

[0047] In an embodiment, the internal cooling channel may instead or in addition be configured to circulate a heating fluid, which may be advantageous e.g. as part of starting up an electrical system after standstill of the electrical system. It may be critical both to safety and functionality that the busbars are dry and moisture condensation disappearing prior to power up a high voltage system, and this may be ensured by heating up the busbar by means of the internal cooling fluid channel. Thesame fluid circulated in the internal channel may be used for heating or cooling depending on the temperature of this fluid and the ambient temperature such as the temperature of the busbar. Hence, prior to start-up, the busbar may have a temperature that is below the temperature of the fluid and thus the fluid may act as a heater for the busbar. During operation, the temperature of the fluid may be lower than the temperature of the busbar and thus act as a cooler for the busbar. Thus, even though the channel may be referred to as a cooling channel it may in fact be used to heat up the busbar before start of operation of the electric system.

[0048] In an embodiment said at least one internal channel extends in a longitudinal direction of said busbar.

[0049] Note, that the internal channel does not necessarily need to extend between the terminals or the first and second ends of the busbar. The ends may also comprise the internal channel, i.e., the internal channel may extend from one end to the other of the busbar. It should be mentioned that a non-linear extending channel, e.g. bending and twisting, e.g. having an S-like form from side to side in the transversal direction of the busbar, is also considered as extending in the longitudinal direction of the busbar. This S-shape or zigzagging through the busbar, or similar non-linear channel paths, may have the effect that a large area of the busbar may be cooled or temperature regulated by a flow of fluid in the channel. Such design is a trade-off between the desired cooling of the entire busbar, flow of fluid and conductance of current through the busbar.

[0050] Having more than one internal cooling channel may be advantageous in that the busbar then has more surface when high frequency current is conducted due to the skin effect. Further, a larger part of the cross-sectional area of the busbar is possible to temperature regulate. Further, it has the effect, that heating / cooling fluid having different temperatures can flow through different parts of the busbar. A plurality of channels also allows to circulate the same coolant forth and back between the ends of the busbar, or allows to have several separate flows. A plurality of internal channels may be provided in different layers of the cross-sectional area of the busbar, for example aligned, to reduce impact om the current path through the busbar. Severalseparate internal cooling channels also allows for cooling different parts, different heat transfer regions, of the busbar differently. As an example, where the busbar has the highest temperature (and an internal channel), the fluid with the lowest temperature may advantageously be conducted. Accordingly, a return path, carrying less cool coolant, may be passed through a part of the busbar with less heat challenges.

[0051] An internal cooling channel may also branch off into two or more internal channel branches. This may be advantageous as it allows the internal channel to follow several or all conductor branches of a busbar that comprises a plurality of conductor branches, for example in connection with a flexible region.

[0052] In an embodiment said at least one internal cooling fluid channel has a geometry selected from the list comprising: gyroid-like, web-like, circular, oval, triangular, rectangular, square, pentagon and multi sided.

[0053] The design of the geometry of the internal cooling channel should preferably provide as little flow resistance as possible. With this said it may be appreciated to establish some swirling effects in the flow through the internal channel to increase e.g. a cooling effect thereof. This may be achieved by providing the walls of the internal channel with recesses in a predetermined pattern such as known from a rifle barrel. In addition, as mentioned, it is desired to have a surface of the channel that is as large as possible to increase, e.g., the cooling capacity. The combination of these demands may, e.g. by the software designing the busbar, result in what is referred to as a bionic design, i.e. a logic design in which current paths are not predictable in size or direction.

[0054] In an embodiment said at least one internal channel is configured to receive tubing.

[0055] Tubing, such as a pipe, polymer tube, etc., e.g. in the form of an insulated hose may be inserted into the internal channel e.g. when the busbar with internal cooling channel is manufactured, prior to mounting, or after the busbar is mounted in its target system. This is advantageous in that it has the effect, that no connection of an external channel to the internal cooling channel is needed. The tubing may simplybe circulating the cooling fluid from a heat exchanger through the electrical busbar via the internal cooling channel and back to the heat exchanger.

[0056] In an embodiment said at least one internal channel comprises a plurality of flow guides.

[0057] Flow guides are advantageous in that they may be designed to establish a particular flow of cooling fluid inside the internal channel. Such particular flow may include establishing a swirling effect in the flow of e.g. a cooling fluid inside the internal channel and thereby increase cooling effect of the cooling fluid. The individual flow guides may have non-uniform geometries, i.e. different geometries, such as one flow guide being cylindrical, another oval, one may be triangular, etc. Having flow guides with non-uniform geometries is advantageous as a non-uniform flow of cooling fluid through the internal cooling channel is obtained, which may lead to an increased cooling effect of said cooling fluid in the heat transfer region. The individual flow guides may be outgrowing from an inner wall of the internal cooling channel in different directions. Hence in an embodiment, one flow guide may outgrow from one side of a rectangular internal channel towards an opposite second side, and another flow guide may outgrow from the second side towards the one side. Another flow guide may outgrow from one of the third and fourth sides, etc. Such varying outgrowing flow guides may lead to a desired or controlled flow of cooling fluid which may increase or decrease flow speed, create a swirling effect, etc.

[0058] In an embodiment said at least one internal channel is monolithically formed with a channel extension.

[0059] A channel extension facilitates easy connection to e.g. a cooling loop of an external cooling channel. Monolithically forming the internal channel and the channel extension makes connection of the internal channel to e.g. a cooling system easy. The channel extension may be seen as the internal channel extending outside the busbar’s footprint to facilitate external connection. An external channel / cooling loop such as a plastic pipe may be connected to the channel extension and thereby with the inner channel. Thus, easy mounting of cooling loop is possible. It should be mentioned thatthe channel extension may be of a different type of material than the busbar. In such case it may be more correct to refer to a polylithic formed internal channel and channel extension. The channel extension may comprise a threaded part, for easy connection to a hose or pipe with a union not or bushing. The channel extension may be manufactured by additive manufacturing in the same electrically conductive material as the busbar, thereby simplifying manufacturing in one process with the busbar.

[0060] In an embodiment said internal cooling channel is monolithically formed with said busbar in an electrically conductive material.

[0061] Manufacturing an electrical busbar with a heat transfer region, for example comprising an internal cooling channel, by an additive manufacturing process is advantageous in that not only the internal cooling channel may be monolithically formed with the busbar, but also cooling channel inlets and outlets may be monolithically formed with the busbar. Thereby the internal cooling channel do not require separate fittings, union nots, etc., for connecting the internal cooling channel to an external cooling channel.

[0062] In an embodiment said at least one auxiliary function region comprises an electrically insulated region.

[0063] By electrically insulated region is understood a segment, surface area or otherwise part of the electric busbar, which comprises an electrically insulating layer or separator to shield operators and technicians, allow for mounting on metallic structures, provide required separation to adjacent busbars, components or mechanical structures and / or reduce the risk of short circuits. The electrical insulation region may be applied by additive manufacturing to a provided busbar, or the busbar with integrated electrically insulating region may be produced by two-material additive manufacturing as described below. Electrical insulation regions located at selected portions of the busbar surface may avoid a manual post-process of applying electrical insulation material, avoid separate insulation elements for mounting and busbar crossings, and allow for irregular insulation region shapes and locations targeting the specific insulation requirements of the electrical system without any additional effort.An electrically insulated region provided by additive manufacturing may also comprise internal electrical insulation, e.g. inside a cooling channel to enable using more or less conductive cooling fluids, or be provided between busbar strands or coprinted two or more phase conductor busbars for busbar separation. An electrically insulated region that is manufactured by additive manufacturing may in an embodiment be formed to further define channels or other cavities or enclosures, for example to convey cooling fluid and / or liquid insulators, or to hold sensors, wires for communication or control signals, etc.

[0064] In an embodiment said busbar comprises an electrically conducting component and said electrically insulated region is formed by an electrically insulating component formed by an electrically insulating component.

[0065] Combining insulating and conducting material in one assembly which is at least partly 3D-printed or otherwise manufactured by additive manufacturing, may be highly advantageous, as it facilitates more freely designing shapes, geometries, profiles, etc., of the busbar, for example when utilizing the opportunity in additive manufacturing of producing geometries or profiles that would not be possible to manufacture by traditional methods like moulding or extrusion. Likewise, new features of partly insulated busbars may be facilitated by the present invention, which are also not possible or feasible to achieve with traditional methods.

[0066] More detailed examples are described below with reference to the drawings, while here just mentioning a few non-limiting examples, such as a busbar having integrated insulation inside channels in the conducting component to allow internal cooling or insertion of wires, sensors, etc.; a busbar being insulated on a non-uniform web-like or bionic-like part of the conducting component to facilitate better cooling or flexibility while still ensuring proper insulation; targeted partly or non-uniform coverage by insulation at exposed or accessible portions of the busbar in particular for high-power systems; inherent non-insulation by design at terminals and other locations where access to the conducting component is required to avoid manual removal of insulation with possible damaging the conductor at such locations; a busbar having several conductors or conductor strands or branches which are interweaved in a waythat is not easily achieved by combining individually manufactured conductors, and which require insulation between them to allow for small inter-conductor distances; a busbar having insulated mounting points thereby avoiding manually adding mounting points and insulation in post-processing or mounting on non-conducting structure; etc.

[0067] The present invention may be particularly advantageous for specialized busbars where certain shape, flexibility, rigidity, cooling options, mounting, terminals, etc., is required or beneficial in combination with certain insulation requirements. A busbar with one or more of a complex shape, integrated flexibility at a certain location, larger cooling surface area than simple circular or rectangular cross sections allow, with predetermined mounting points and terminal points, targeted partial insulation or internal insulation, etc., may advantageously be provided by manufacturing one or more insulating component together with, or directly on, one or more conducting component of the busbar by additive manufacturing.

[0068] An electrically insulating component is configured to provide electrical insulation of one or more of the electrically conducting components, for example of the entire surface, selected parts of the surface, or between electrically conducting components that are intended to carry individual electrical potential. The electrical insulating component may be based on or contain a material, such as a solid or enclosed liquid or gas, in which electric current does not flow freely, i.e. has a higher, preferably significantly higher, electrical resistivity than materials typically used for conductors and semiconductors. As all insulators may conduct very small currents and / or breakdown at certain high voltages or temperatures, the material and design of the electrically insulating component is preferably based on the intended properties and use case of the busbar, in particular its electrical and thermal properties such as intended voltage and current, required thermal endurance, the physical dimensions of the busbar and distances to other conductors, structures or persons during use. For instance, a different insulation material and / or thickness may be selected for high- voltage busbars compared to busbars intended for low-volage electronics.

[0069] In embodiments where both the conducting and insulating components, i.e. different materials, are manufactured by additive manufacturing, the manufacturingtechnology may preferably support application of different materials in one work process, such as simultaneously or synchronously, such as alternatingly, to facilitate producing the busbar including electrically insulated region as one single workpiece. Synchronously, as used herein, refers to coordination in time and / or space, for example providing two different materials at two different locations on the part at the same time, or providing two different materials alternatingly, for example providing the conducting material for a particular additive manufacturing layer, then the insulating material for the same particular layer, then moving on with the conducting material for the next layer, etc. Additive manufacturing technologies supporting applying two or more materials simultaneously, synchronously or alternatingly, i.e. multi-material additive manufacturing, may for example include fused deposition modeling FDM when provided with two nozzles and two filaments, one being a conducting material and the other an insulating material, or may for example include cold spray additive manufacturing CSAM when provided with two spray nozzles for spraying conductive and insulating material, respectively. Other two-material 3D printing technologies also exist, including combinations of two technologies for conducting parts and insulating parts, respectively. Multi-material additive manufacturing, as used herein, generally means that a part consisting of more than one material, can be produced using additive manufacturing without intermediary manual steps being required, such as moving a part from a metal printer to a plastic printer, or the like.

[0070] In embodiments, where the electrically insulating component is applied to a busbar as a separate manufacturing step, it may advantageously be performed by for example cold spray additive manufacturing CSAM, fused deposition modeling FDM, stereolithography SLA, etc.

[0071] In an embodiment said electrically insulating component is manufactured together with said electrically conducting component by multi-material additive manufacturing.

[0072] Complex busbars requiring insulation may advantageously be produced by multi-material additive manufacturing, where an electrically insulating material and an electrically conducting material are applied alternatingly or simultaneously to formthe desired busbar, thereby enabling creation of busbars that would not be possible to obtain as one single piece before. For busbars where one of the components are not strictly necessary to manufacture by additive manufacturing, it may anyway be beneficial to utilize multi-material additive manufacturing to achieve the complete busbar in one process step. Some of the possible technologies for multi-material additive manufacturing are mentioned above.

[0073] In an embodiment said electrically insulating component is manufactured by additive manufacturing onto a surface of said electrically conducting component.

[0074] The electrically conducting component may be provided from, e.g., extrusion or a molding process or any other manufacturing technology for conductors, including a separate additive manufacturing process, e.g. selective laser melting SLM. The electrically conducting component may for example be in the form of an elongated sheet or slab, a bar or rail, etc., onto which the electrically insulating component can be created by additive manufacturing to form together a busbar having an electrically insulated region. The pre-manufactured electrically conducting component may also be a complex geometry, such as web-like or bionic, onto which insulation is applied by additive manufacturing to form the final busbar. The application of electrically insulating component by additive manufacturing may for example be achieved by fused deposition molding FDM, cold spray additive manufacturing CSAM, stereolithography SLA, etc.

[0075] In an embodiment the electrically insulating component forms one or more transversal bands on the electrically conducting component.

[0076] In various embodiments, it may be advantageous that the busbar is covered with an insulating band at positions along its extent, at regular or irregular intervals, for example at mounting or support locations, or other busbar crossings.

[0077] In an embodiment said electrically insulating region comprises a material selected from the list of polymers, ceramics, thermoplastics, glass reinforced plastic, rubber, glass, wood, paper, oil, deionized water, or combinations thereof.

[0078] In embodiments where ceramic coating is feasible, this may be an advantageous option for the electrically insulating component, due to excellent electrical insulation properties, in combination with having better thermal conductivity than many other electrically insulating materials. In embodiments where a liquid insulator is feasible, oil may be an advantageous choice, as it may additionally serve as a cooling fluid.

[0079] In an embodiment said at least one auxiliary function region comprises a flexible region wherein said plurality of conductor branch elements are spaced apart by airgaps establishing a line-of-sight through said electrical busbar.

[0080] By flexible region is understood a segment, surface area or otherwise part of the electric busbar, which has increased flexibility compared to a traditional solid metal block busbar. The provided flexibility may be in one or more directions, such as allowing for one or more of twisting, bending, cushioning, vibration absorption, etc. A flexible region may for example be able to facilitate on-the-fly adjustments during mounting or replacements to accommodate tolerances, absorb mechanical shocks and vibrations, be tolerant to temperature-induced changes in dimensions, etc., any of which may be improvements over rigid busbar bending machined at a workshop, ad- hoc drilling of new mounting points and terminals, and / or welding or otherwise connecting together separate busbar parts to match other parts of the electrical system.

[0081] An electrical busbar with a flexible region may facilitate manoeuvrability, e.g. by allowing deforming so that it fits to the application to which it is designed. The flexible region may be designed and manufactured with a base tension to maintain a given posture in relaxed state i.e. when no external force is applied (except from gravitational force).

[0082] Line of sight should be understood as possible to see through by a human eye i.e. line of sight should not be understood as an airgap which only allow e.g. a flow of air. Line of sight may be in a particular direction or a plurality of different locations along the length of the busbar

[0083] In an embodiment said flexible region comprises a middle segment of said busbar formed by a plurality of conductor branch elements, such as one or more conductor branches.

[0084] This may have the effect, that the geometry of the middle segment, and thereby the busbar, is able to change upon applying a force. The force may be applied by a person or a component mechanically connected / in contact with the busbar. In this way a flexible busbar is provided which is easy to mount and may absorb vibrations. A change in geometry lead to a change of position and / or orientation in space of at least one of the ends of the busbar.

[0085] The busbar may be considered comprising at least one first end segment, at least one second end segment, and the segment of the busbar defining the flexible region being a middle segment somewhere between the first and second ends.

[0086] A busbar with a flexible region may facilitate damping of vibrations, e.g. in an electrical installation. Particularly, a busbar with end segments monolithically coupled electrically and mechanically by a plurality of conductor branches spatially separated in two different transversal directions of the busbar, may be capable of improved vibrational damping in any of the transversal directions while potentially minimizing the risk of structural damage. Further, the spatial separation of conductor branches in two transversal directions may additionally permit improved heat dissipation while potentially minimizing the risk of the above-mentioned structural damage. Large currents and varying weather conditions may result in a large span of temperatures in renewable energy facilities. By having the plurality of conductor branches monolithically formed with the first and / or second end and distributed in two transversal directions, the busbar may be able to better tolerate thermal expansion under such conditions.

[0087] A conductor branch may be understood as an elongated protrusion for facilitating flow of charge and damping of vibrations, preferably in combination with other conductor branches. The conductor branches may have the shape of a cylindrical or polygonal rod, e.g. a square or hexagonal cross section, or more irregular shapes,such as web-like, bionic, etc. A conductor branch may fork into two, or even more than two diverging conductor branch twigs. Such diverging conductor branch twigs may connect with other conductor branches in intersection points.

[0088] The first and / or second end of the busbar and the conductor branches are monolithically formed, which may be understood as consisting of a single unit, part, or piece, manufactured in a single process. For example, the conductor branches may be formed with the first end without seams or joints. The flexible region, i.e. the conductor branches providing the flexibility are manufactured by additive manufacturing.

[0089] In an embodiment a plurality of conductor branches are mutually twisted without physical contact between the individual conductor branches in the longitudinal direction of the middle segment.

[0090] The conductor branches are both electrically and mechanically connected at the first and second ends, but along the longitudinal direction of the middle segment, in this embodiment, there are no electrical and mechanical connection between the individual conductor branches. In other words, even though the conductor branches are twisted, they keep transversal distance to each other, at least in a base position with no force applied. A twisted busbar design may be advantageous in that it allows for obtaining tolerances both in the longitudinal direction, sideways, and axial.

[0091] In an embodiment the busbar comprises a first end and a second end spaced apart by said middle segment, and wherein at least part of at least two of said plurality of conductor branch elements are spaced apart by an airgap in a longitudinal direction of the busbar.

[0092] The airgap should be understood as a space between part of two conductor branch elements, and is ensuring that the two parts of the two conductor branch elements are not in physical contact when the busbar is in a resting position i.e. when there is no force apart from gravitation acting on the busbar. The two conductor branch elements may be elements of the same conductor branch, or two different conductor branches.

[0093] The airgaps are spacing apart parts of the conductor branch elements in the longitudinal direction of the busbar. Hence, such airgaps may be defined from a position at a part of one conductor branch to a position on a part of another conductor branch in the direction towards one of the two ends. The conductor branches may be designed and subsequently produced in a harmonica-like shape, spiral-like shape, etc. leading to a plurality of airgaps between parts of the same busbar.

[0094] The plurality of conductor branch elements may form a single conductor branch. It should be mentioned that an electrical busbar may be built from a mix of conductor branch elements formed by individual conductor branches and by one or more conductor branch(es) forming two or more conductor branch elements.

[0095] The busbar is preferably manufactured as a monolithic part including terminals, first and second ends and middle segment in one and the same piece without having to physically connect two or more of these elements. Thereby the manufacturing of the electrical busbar can be done in one process step, i.e. an additive manufacturing process.

[0096] In an embodiment said airgap is in the range of 0.01cm to 40cm, for example below 20cm, 15cm or 10cm, such as below 1cm, such as below 0.5cm, for example below 0.25cm,

[0097] As can be understood, the size of the airgap is a design choice which may depend on the dimensions of the busbar, the intended current and voltage ratings, the kind of electrical installation in which the busbar is installed and the required degree of flexibility. Typically, larger electrical installation may require larger airgaps.

[0098] In an embodiment said conductor branches are configured so that said airgaps change geometry as consequence of a force applied to said busbar.

[0099] A change in geometry may include a change is distance between two points in one way or the other i.e. the distance between two conductor branch elements may either increase or decrease. If the airgap is a closed airgap defined by e.g. four parts of two or more conductor branch elements, the airgap may be a rhomb-like form. Suchrhomb-like form may change geometry by changing distance between the diagonal corners of the rhomb-like form.

[0100] It should be mentioned that the deformation creating the change in geometry of the airgap may happen distant from the parts between which the airgap is established. Hence, the parts between which the airgap is established may be straight parts between bended parts of the conductor branch elements. Thus, the deformation may happen at the bended parts and not at the straight parts.

[0101] A plurality of airgaps may be established between the plurality of conductor branch elements in the longitudinal direction of said electrical busbar. This is advantageous if a highly flexible / deformable busbar is required in that the more airgaps, the more flexible the busbar becomes.

[0102] The plurality of conductor branch elements may be configured to deform so as to change geometry of one subset of said plurality of airgaps differently from a second subset of said plurality of airgaps. While a first subset of airgaps is increased in size e.g. the distance between two conductor branch elements is increased, the distance between a second subset of airgaps is decreased in size e.g. the distance between two conductor branch elements is decreased.

[0103] In an embodiment said airgap is extending between at least two of said conductor branches and separates said at least two conductor branches in the longitudinal direction of said conductor branch between said first end and said second end.

[0104] At least two of the plurality of conductor branch elements may meet in an intersection point and at least two conductor branch elements may branch off from the intersection point. This may have the effect, that an electrical busbar is established that maintain a desired strength (determined yield point) with a minimum of material. Thereby reducing the cost of material which as mentioned is electric conductive and therefor relatively expensive. It should be mentioned that the two conductor branch elements meeting in the intersection point may be the same two conductor branch element leaving that intersection point. Alternatively, two other conductor branchelements may leave the intersection point, however this may be a question of definition of a conductor branch element.

[0105] Web-like structure and bionic structure are advantageous in that they both may provide strength and current conducting capability required by the busbar. A bionic designed structure should be understood as a structure with a design that technically implements abstracted principles of nature. Bionic design may at first glance look unpredictable, but is in essence an optimized minimalistic and logic structure optimised according to strength, structure, cooling, use of material, conductance of current, etc. An example could be a support structure or electric conductor that is computer generated to comply with certain requirements leading to a structure / design that is not possible or very difficult and time consuming for a person to establish.

[0106] In an exemplary embodiment the airgap is an axial airgap, which is understood as an airgap that is following conductor branches / conductor branch elements forming a tubular electrical busbar around the tubular perimeter. In this way, two conductor branches may extent between the ends along a path that is not the shortest therebetween and all along this path the axial airgap is separating the two conductor branches. This is advantageous in that such design of a busbar is flexible i.e. elastically deformable.

[0107] In an exemplary embodiment the airgap separate said at least two conductor branch elements in a transversal direction of said busbar.

[0108] In an exemplary embodiment, at least one of said plurality of conductor branch elements is longer than the shortest distance between said first and second end, and wherein said busbar is configured to change geometry by a deformation of said one or more conductor branch elements. This may achieve the effect, that the busbar becomes flexible, enabling the busbar to absorb vibrations and allows for flexible mounting to mounting points of an electric component that is not completely aligned with fastener holes of the terminals.

[0109] Change of geometry should be understood as physically stretching, twisting, bending, etc. of the electrical busbar as consequence of a force being applied to part of the electrical busbar. Such change of geometry has the effect that the distance between the first and second ends is changing, orientation in space of the first and second ends relative to each other is changing, rotation around a longitudinal axis of the busbar of one of the first and second ends relative to the other, etc.

[0110] The force applied to the busbar is typically applied to one of its two ends, more specifically to the terminals connecting the busbar to another electric part e.g. in an electric panel. The force can be applied from any orientation e.g. perpendicular to the longitudinal axis of the busbar which will result in a bend of the busbar. Alternative, the force may be applied parallel to the longitudinal axis of the electrical busbar which will result in a compression of the busbar. Alternative, the force may be applied between parallel and perpendicular to the longitudinal axis leading to a mix of bend and compression of the busbar. The force can also come from the weight of the busbar itself by gravitation.

[0111] It should be noted, that in an embodiment the plurality of conductor branch elements are implemented as what may be referred to as a plurality of individual conductor branches. Hence, the flexible region of the busbar may include a conductor branch that is longer than the shortest distance between two ends of the flexible region, and wherein the busbar is configured to change geometry by a deformation of the one or more conductor branches.

[0112] Preferably, the deformation is an elastic deformation, meaning that the electrical busbar can be adapted to fit in different configurations and still be able to return (deform back) to its originally form / geometry. Thus, the busbar is configured to reshape to its original geometry as consequence of removal of the deforming force. The force required to elastically deform the busbar is depending on one of the cross- sectional area, length, geometry, etc. of the conductor branches. Further, designing an electrical busbar utilizing a plurality of branches / branch elements will provide a more flexible component than if it was designed in the traditional way, i.e. with one solid cross-section. Thus, the force needed to flex, i.e. elastically deform, the electricalbusbar of the present invention is less than to deform a traditional busbar complying with the same requirements to current conductance. It should be mentioned that the force required to reach the level of stress corresponding to the material yield point is a design choice and therefore the force required to elastically deform an electrical busbar is typically a design choice and thus often individual for a certain electrical busbar.

[0113] In an exemplary embodiment the deformation is a plastic deformation, which may be advantageous as the electrical busbar can be adapted to fit in configurations that, if no deformation of the electrical busbar was made, did not allow use of the busbar. Hence, a busbar of the present invention may be partly mounted or inserted in a panel, then plastically deformed, e.g. behind or beside other components of the panel, to make it fit to the space allowed for the electrical busbar. Put in another way, the geometry of an electrical busbar according to the present invention can be offset providing flexibility relative to a new relaxed shape. Configuration in this context should be understood as electric systems in general.

[0114] In an embodiment the cross-sectional areas of individual of said one or more conductor branches are equal to or below 200mm2, preferably below 150 mm2, preferably below 100mm2, preferably below 50 mm2, preferably below 10 mm2, most preferably between 0.5 mm2and 5 mm2.

[0115] The busbar with flexible region having plurality of conductor branches is advantageous in that even with relatively thick conductor branches of, e.g. cross sections of 10mm2or 20mm2, the busbar may still be flexible. It is however evident that the thinner conductor branches, the less a force is needed to deform the busbar. Further, this is advantageous that different cross-sections can change the flexibility of the busbar.

[0116] In an embodiment conductor branches of the flexible region are manufactured by additive manufacturing.

[0117] As understood form the above-described embodiments of a flexible region based on a plurality of conductor branches in various configurations, it may be impossible or highly challenging to manufacture a busbar with such a flexible regionby normal production methods. Using additive manufacturing for this may be highly advantageous, as it allows for complex interweaved, twisted, bent, etc., geometries of the flexible region, further achieving a high degree of freedom for the designer to take into account other requirements or desires, such as reducing material, matching certain outer maximum dimensions or other external limitations, allowing for various cooling systems, etc.

[0118] In an embodiment said at least one auxiliary function region comprises a mechanical support region.

[0119] By mechanical support region is understood a segment, surface area or otherwise part of the electric busbar, which is designed specifically for mechanically supporting other components or conductors of an electrical system. For example, a mechanical support region may comprise bolt holes, tongues or grooves, hooks, slots, flanges, etc., at which electrical components or conductors can be mounted or supported, e.g. by fastening, hanging, sustaining, binding, clamping, etc. In various embodiments, mechanical support regions may for example hold insulations sheets or other separators in place between electrical components, or hold the electrical components themselves in place.

[0120] In an embodiment said mechanical support region comprises additional busbar material or an increased density of busbar material, compared to an average of the busbar.

[0121] The additional material or increased density of material, such as conductive material, e.g. copper, aluminum or conductive alloys, at the mechanical support region, may for example be designed and provided for allowing sufficient fastening of screws or clamps without damaging possibly less robust segments, e.g. a heat transfer region comprising an ‘airy’ geometry.

[0122] In an embodiment said mechanical support region comprises protrusions from said busbar.

[0123] Besides facilitating safety clearance and organization of components, objects and panel structure, a protruding mechanical support regions may also avoid influencing the primary current path of the busbar by the auxiliary function of mechanical support.

[0124] In an embodiment said mechanical support region comprises one or more support items selected from the list of: through hole for bolts or screws, protruding rod, threaded protruding rods, flange, hook, clamp, clip, groove, threaded bolt hole, a polygonal countersunk cavity to receive a bolt head, or combinations thereof.

[0125] In an embodiment said mechanical support region is monolithically formed with said busbar by additive manufacturing.

[0126] In an embodiment said at least one auxiliary function region comprises a mounting region.

[0127] By mounting region is understood a segment, surface area or otherwise part of the electric busbar, which is designed specifically for mechanically mounting or supporting the busbar itself to another structure. For example, a mounting region may comprise bolt holes, tongues or grooves, hooks, slots, flanges, etc., at which the busbar can be mounted or supported, e.g. by fastening, hanging, sustaining, binding, clamping, etc. In various embodiments, mounting regions may for example be used mount or support the busbar at a mechanical support structure, e.g. a frame, cabinet, panel, etc.

[0128] In an embodiment said mounting region comprises additional busbar material or an increased density of busbar material, compared to an average of the busbar.

[0129] The additional material or increased density of material, such as conductive material, e.g. copper, aluminum or conductive alloys, at the mounting region, may for example be designed and provided for allowing sufficient fastening of screws or clamps without damaging possibly less robust segments, e.g. a heat transfer region comprising an ‘airy’ geometry.

[0130] In an embodiment said mounting region comprises protrusions from said busbar.

[0131] Besides facilitating safety clearance and organization of the busbar, a protruding mounting region may also avoid influencing the primary current path of the busbar by the auxiliary function of mounting region.

[0132] In an embodiment said mounting region comprises one or more support items selected from the list of: through hole for bolts or screws, protruding rod, threaded protruding rod, flange, hook, clamp, clip, groove, threaded bolt hole, a polygonal countersunk cavity to receive a bolt head, or combinations thereof.

[0133] In an embodiment said mounting region is monolithically formed with said busbar by additive manufacturing.

[0134] In an embodiment said at least one auxiliary function region comprises a flow guiding region.

[0135] By flow guiding region is understood a segment, surface area or otherwise part of the electric busbar, which is designed to guide a flow, preferably a flow of cooling fluid such as air being circulated inside an electrical system cabinet, or cooling fluids, e.g. liquids, flowing through cooling channels of the electrical busbar. A flow guiding region may for example comprise fins, dents, vortex generators, etc., to control, guide, focus, diffuse or disturb cooling fluid flow. Thereby cooling of an electrical system can be improved with a reduced amount of separate flow guiding arrangements.

[0136] In an embodiment said flow guiding region comprises at least one air guide.

[0137] An electrical busbar comprising an air guide is advantageous in that it has the effect, that it facilitates both guiding a cooling fluid, such as air, to and possible also around an electrical component to which it is connected or passing by in an electrical cabinet. Such catching and guiding of air flow is achieved while, at the same time, improving the cooling of the electrical busbar itself and supplying the electrical component with power without the need for additional air guiding components.

[0138] In an embodiment said at least one air guide is removably attached to said electrical busbar at said flow guiding region.

[0139] This is advantageous in that it has the effect, that it is possible to adjust the position of the air guide on the busbar. Thus, it is possible to adjust airflow directly to a hot spot e.g. of an electrical component or an area which need cooling by airflow. In fact, it may be possible during operation of an electrical system to establish a thermography of the electrical system and based on an evaluation of the resulting picture adjust or position one or more the air guides to guide flow of air to relevant areas. Air guides may be attached to the busbar by clamping, screwing or the like. Air guides may be made of a resin, polymer or other suitable materials, preferably materials that are possible to use to manufacture the air guides by additive manufacturing. The flow guiding region of the busbar may comprise air guide fasteners configured to fix the air guides. Having guide fasteners formed in / as part of the surface of the busbar is advantageous as external air guides are easy to mount and adjust on the busbar at the correct position and with a correct angle for guiding an air flow e.g. to a heat generating component. Such integrated guide fasteners are advantageous in that they can be manufactured simultaneously with the manufacturing of the busbar, for example by additive manufacturing.

[0140] In an embodiment said at least one air guide is an integrated part of said electrical busbar at the flow guiding region.

[0141] An integrated air guide is advantageous in that it has the effect, that no additional components are needed to distribute an air flow around or along the electrical busbar.

[0142] In an embodiment said middle segment with said at least one integrated air guide is one monolithic geometry manufactured by additive manufacturing.

[0143] A middle segment and an integrated air guide monolithically formed is advantageous in that it eliminates the need for mounting the air guide on said the surface of said middle segment. This is because the middle segment and the air guide is one and the same structure.

[0144] In an embodiment said at least one air guide is integrated as part of said electrical busbar as a protrusion at the surface at said flow guiding region.

[0145] An air guide in the form of a protrusion is advantageous in that by the design of the protrusion, the flow of air can be directed to a predetermined area or location in the vicinity of the electrical busbar.

[0146] In an embodiment a plurality of individual air guides is outgrowing from the surface of said busbar at the flow guiding region in different directions.

[0147] Hence in an embodiment, air guides outgrow from different sides of a rectangular busbar. Such varying outgrowing air guides may lead to a desired or controlled flow of cooling fluid which may increase or decrease flow speed, create a swirling effect, etc. and thereby increase the overall cooling of the electrical cabinet or increase the area inside the electrical cabinet cooled by the flow of cooling fluid. Protrusions or outgrowths are advantageous in that in addition to guiding air they may also act as heat sinks and thereby be used to cool the busbar and / or the component to which the busbar is connected.

[0148] In an embodiment said at least one air guide is integrated as part of said electrical busbar as a recess at the flow guiding region.

[0149] An air guide in the form of a recess is advantageous in that by the design of the recess, the flow of air can be directed to a predetermined area or location in the vicinity of the electrical busbar.

[0150] In an embodiment the surface of flow guiding region is dimpled.

[0151] This is advantageous in that it has the effect, that a dimpled surface creates a turbulent flow of air over the surface of the busbar and thereby an increased cooling of this surface.

[0152] In an embodiment said at least one air guide has a geometry selected from the list comprising: circular, oval, triangular, rectangular, square, pentagon and multi sided.

[0153] The design of the geometry of the air guide may be determined by the desired way to split or guide the flow of cooling fluid inside e.g. an electrical cabinet.

[0154] In an embodiment said at least one air guide is formed by the electrically conductive material of said busbar.

[0155] Forming the air guide in an electrically conductive material is advantageous in that it then may be formed in the same material as the electrical busbar. Thus, the electrical busbar and the air guide may be formed simultaneously i.e. as the surface of the busbar is formed or manufactured, the integrated air guide may also be formed or manufactured by additive manufacturing.

[0156] In an embodiment said at least one air guide is formed as a concave geometry in the surface of said busbar at the flow guiding region.

[0157] This is advantageous in that such concave geometry may form a funnel like geometry guiding a flow of air caught by said funnel to an inlet opening of an internal cooling channel of said electrical busbar. Additional air guides provided in the surface of said electrical busbar may assist in guiding a flow of air into said funnel or through the electrical busbar if the design thereof allows so.

[0158] In an embodiment said at least one air guide is integrated in a first and / or second end of said busbar.

[0159] Having air guides at the surface of the ends of the electrical busbar is advantageous in that heat generated at the connection between the terminals of the electrical busbar and an electrical component to which it is connected can be removed. In this and similar situations, an air guide is advantageous over known ways of controlling a flow of air inside an electric cabinet to remove heat. By the present invention, this may be obtained simply by extending the ends of the electrical busbar beyond one or more of the terminals to establish more area of the busbar which can be used as air guides.

[0160] In an embodiment said at least part of busbar and said air guide are manufactured at least partly, simultaneously, by an additive manufacturing process.

[0161] Manufacturing an electrical busbar according to the present invention by an additive manufacturing process is advantageous in that the ends and middle segment of the busbar including air guides may be monolithically formed. This is advantageous in that it has the effect, that the air guides are perfectly secured to the busbar and thus the risk of them falling off is reduced significantly.

[0162] In an embodiment said at least one auxiliary function region comprises a reduced material region.

[0163] By reduced material region is understood a segment, surface area or otherwise part of the electric busbar, which has reduced material density or reduced cross section area compared to a traditional solid metal block busbar, and / or compared to an average material density or cross section area of the busbar. Using additive manufacturing for the busbar, it is feasible and advantageous to design the busbar with different densities or cross section areas along the busbar, e.g. depending on the current paths, locations of terminals and mounting regions, heat transfer opportunities at different locations, etc. Heat transfer regions as described above may also make it feasible to create reduced material regions due to the lower temperature requiring less material to carry the same current.

[0164] Hence, an electrical system comprising a busbar as described here, with a reduced material region manufactured by an additive manufacturing process is advantageous in that weight and cost of materials are reduce due to less material being used for the electrical busbars.

[0165] In an embodiment the busbar at the reduced material region comprises a plurality of conductor branch elements.

[0166] This is advantageous in that it has the effect of using less material for making the electrical busbar. The reduced material region with conductor branches has a greater surface area than a conventional solid busbar, which besides saving material, can also help cooling down the electrical busbar. The cooling at the greater surface areas for the busbar elements makes it possible to have the same current in the electrical busbar while having less material.

[0167] Note, that it is particularly challenging to reduce weight and amount of material of a component, such as a busbar, which has requirements relating to vibrational damping, susceptibility to structural damage, and / or current carrying capabilities. Simply removing material may not be feasible since it may lower the capabilities of the electrical busbar below its requirements for a given application, e.g., a particular electrical installation in a particular renewable energy facility. Thus, the prospect of saving / removing material may be evaluated in combination with minimally reducing, maintaining, or even improving other attributes of the electrical busbar.

[0168] In an embodiment the busbar at the reduced material region is manufactured in a geometry from the list comprising: bionic, web, sponge, honeycomb, wavelike, gyroid-like and branch-like.

[0169] Such geometry of the busbar is advantageous in that when one of the above- mentioned geometries are chosen, the amount of material used for the electrical busbar is reduced. It is also an advantage that the surface of such geometries of the electrical busbar is increased in that more surface is then available for cooling and conducting high frequency currents.

[0170] For all the bionic, web, sponge, honeycomb, etc. like geometries these structures, are good for cooling down the electrical busbar. The geometries all comprise less material with a big surface, so the smaller amount of material is easier to cool down and provides a more compact geometry / electrical busbar. Due to the more efficient cooling, it is possible to conduct the same amount of current in the electrical busbar of the present invention using less material compared to a known massive electrical busbar.

[0171] In an example the electrical busbar of the invention could comprise a shell structure and inside a grid of bionic, web, sponge, honeycomb like geometries. The material removed from the classical electrical busbar compared to an embodiment of an electrical busbar according to the present invention forms holes which may be used for cooling the busbar.

[0172] It is also advantageous in that the busbar can be manufactured in specific shapes and dimension according to where the busbar is supposed to be used. The busbar could be made more “airy” if the space is available to optimize the cooling for the busbar and to save material. The busbar could be shaped to curve around other electrical components in e.g., an electrical cabinet, or to have a greater distance to other electrical components to ensure electrical insulation.

[0173] In an embodiment said reduced material region is monolithically formed with said busbar by additive manufacturing.

[0174] In an embodiment said at least one auxiliary function region comprises a heat transfer region and an electrically insulated region.

[0175] The combination of auxiliary function regions of this embodiment may be particularly advantageous for main busbars or transition busbars.

[0176] In an embodiment said at least one auxiliary function region comprises a heat transfer region and a flexible region.

[0177] The combination of auxiliary function regions of this embodiment may be particularly advantageous for transition busbars or shunts.

[0178] In an embodiment said at least one auxiliary function region comprises a heat transfer region, a flexible region and a mounting region.

[0179] The combination of auxiliary function regions of this embodiment may be particularly advantageous for transition busbars or shunts.

[0180] In an embodiment said at least one auxiliary function region comprises at least two partly or fully overlapping auxiliary function regions.

[0181] In some embodiments, the same region or area of the electrical busbar may feature several auxiliary functions. It may be advantageous to combine a heat transfer region and a flexible region for example by branching the busbar into displacedparallel or twisted strains or a web-like or bionic structure with air or other cooling fluid flowing through the branches.

[0182] In an embodiment one or more of the at least one auxiliary function region, such as a heat transfer region or a flexible region, extends to substantially the entire electrical busbar, such as at least 75%, e.g. more than 90% of the busbar surface.

[0183] In some embodiments, an auxiliary function region covers most of the busbar, or even the entire busbar. It may, for example, be advantageous in some embodiments, to build the busbar, except for example the terminals and mounting points, as a heat transfer region by branching most of the busbar into displaced parallel or twisted strains or a web-like or bionic structure.

[0184] In an embodiment one or more of the at least one auxiliary function region is distributed into a plurality of sub regions, e.g. a plurality of electrically insulated regions, mechanical support regions or mounting regions.

[0185] Some auxiliary functions may advantageously be provided at several locations on the electrical busbar, and may thus be considered distributed sub-regions of the auxiliary function region.

[0186] In an embodiment the electrical busbar is manufactured by additive manufacturing as a single workpiece.

[0187] The busbar including the main purpose of current conductance and the at least one auxiliary function region, may advantageously be manufactured as a single workpiece by additive manufacturing. This provides for previously impossible configurations and combinations of auxiliary functions, as well as improved freedom of design. Further is avoided cumbersome manual adaptation of busbars, like drilling holes, which also changes the electrical properties of a busbar, welding pieces, e.g. rigid and flexible portions, to form a complete busbar, bending or otherwise shaping busbars to match the spatial requirements, etc. A single workpiece busbar may also be referred to as a monolithic busbar. When referring to manufacturing by additivemanufacturing as a single workpiece this may also include standard post-processing, such as abrasion, sanding, polishing, coating, etc.

[0188] In an embodiment the additive manufacturing comprises multi -material additive manufacturing.

[0189] This may be particularly advantageous when different materials are preferred for the main function of current conductance and for the auxiliary function, and / or for different auxiliary functions. Multi-material additive manufacturing may for example be utilized for electrically insulating regions, flexible regions, heat transfer regions, etc. Some materials for additive manufacturing may be selected for their electrical conductance or electrical insulation, their heat transfer properties, their rigidity or flexibility, their strength, etc. The manufacturing technology may preferably support application of different materials simultaneously or alternatingly, to facilitate producing the electrical busbar as one single workpiece. Additive manufacturing technologies supporting two simultaneous or alternating materials, i.e. multi-material additive manufacturing, may for example include fused deposition modeling FDM when provided with two nozzles and two filaments, e.g. one being a conducting material and the other an insulating material, or may for example include cold spray additive manufacturing CSAM when provided with two spray nozzles for spraying different materials. Other two-material or multi-material 3D printing technologies also exist, including combinations of two technologies for different auxiliary function regions.

[0190] In an embodiment the additive manufacturing comprises selective laser melting SLS, selective laser sintering SLM or cold spray additive manufacturing CSAM.

[0191] In an embodiment the electrical busbar is a component configured for electrical distribution in an electrical system, e.g. in an electrical cabinet.

[0192] In an embodiment the electrical busbar comprises a main busbar to be mounted along a top, back, side or bottom of an electrical cabinet.

[0193] A main busbar should be understood as an electrical conductor distributing current in an electrical cabinet, a switchgear, panel board or busway enclosure, typically, from one or more cables entering the electrical cabinet to electrical components located inside the electrical cabinet. Typically, the main busbar extends in the width (X direction) or in the height (Y direction) of the electrical cabinet. The main busbar may be fastened to a back plate of the electrical cabinet.

[0194] In an embodiment the electrical busbar comprises a transition busbar, a connecting busbar or a shunt, configured to connect electrical components or other busbars with main busbars or cables.

[0195] A transition busbar, connecting busbar or shunt should be understood as a busbar connecting a main busbar or cable with another main busbar, another transition busbar, with an electrical component, or the like. A transition busbar may also be referred to as a connection or transition piece for connecting two or more electrical components. Typically, a transition busbar extends in two or more directions, where one of these directions is towards the opening of the electrical cabinet (Z direction). Another of these directions is typically perpendicular or parallel to e.g. the main busbar to which transition busbar is connected. The transition busbar may comprise two legs at one end for connecting e.g. two paralleled power modules to one main busbar or to another transition busbar. Transition busbar, connecting busbar or a shunt may also be referred to as a current balancing busbar to connect busbars, branches, terminals, power modules, conductors etc. that ideally should be at the same electrical potential, e.g. corresponding terminals of parallel-coupled power modules or other components, thereby facilitating an improved distribution and balancing of current and heat among the terminals or branches.

[0196] Hence, a current balancing busbar should be understood as a variant of a transition busbar. A current balancing busbar may e.g. be a transition busbar having two or more legs or sets of terminals allowing the connection of two or more power modules i.e. allowing parallelling the power modules. This is advantageous in that it has the effect, that if such current balancing busbar is connected to e.g. two power modules, then the current into or out of these two power modules can be balanced.Such balancing is done via designing the current balancing busbar so that the current path through the two legs of the current balancing busbar has the same ohmic resistance. When this is achieved an equal share of current to and from the power modules is conducted via the two legs. Thereby it is achieved that losses are the same in both legs leading to equal wear and temperature increase.

[0197] In an embodiment the electrical busbar comprises two or more, such as three, separate phase conductors, each having first and second terminals and supporting individual current conductance between the respective first and second terminals, preferably wherein each separate phase conductor comprises at least one of said at least one auxiliary function region.

[0198] This embodiment may be highly advantageous as for example a high-power three-phase busbar for energy distribution in high-power electrical systems, which can be manufactured in a single unit by additive manufacturing, and can be mounted and replaced as a single unit. The auxiliary function region may advantageous, for example, comprise an electrically insulating region as described above, to separate the three separate phase conductors, to commonly insulate the assembly from surroundings, to provide mechanical support for the phase conductors, provide insulated mounting points for the busbar, or combinations thereof. The auxiliary function region may in addition or instead advantageously, for example, comprise a heat transfer region and / or flow guiding region as described above for facilitating conductance of high currents at lower temperature and loss. The auxiliary function region may in addition or instead advantageously, for example, comprise a flexible region as described above for absorbing vibrations and loosen the tolerance requirements for mounting and electrical connections. The auxiliary function region may in addition or instead advantageously, for example, comprise a mechanical support region and / or mounting region as described above for facilitating installation and maintenance. The auxiliary function region may in addition or instead advantageously, for example, comprise a reduced material region as described above for reducing weight and costs, and / or allowing for airy geometries to also improve heat dissipation.

[0199] In an embodiment said electrical busbar has a resonance vibration frequency of at least 5 Hz, for example at least 20 Hz, for example at least 30 Hz, for example at least 70 Hz, for example at least 150 Hz for example at least 300 Hz, for example at least 500 Hz.

[0200] The electrical busbar is advantageously designed and subsequent manufactured so that it has a resonance vibration frequency associated with relative motion between the first end second ends that is does not coincide with a natural frequency of the electrical system in which it is included. This is to avoid vibrations initiated by natural frequencies from such electric system or mechanical system. An example of a mechanical system is a wind turbine which may have a natural frequency of, for example, around 5Hz.

[0201] In an embodiment the electrical busbar is a high-power electrical local connecting busbar.

[0202] The present invention is particularly advantageous for electrical busbars designed for high-power electrical systems, e.g. from lOkW and up, such as 22kW, 50kW, HOkW, 150kW, 225kW, 300kW, 350kW, 500kW, 800kW, 1MW, 2MW, 3 MW, or even higher, such as e.g. 5MW or 10MW systems, with voltages of e.g. 110V, 230V, 400V, 690V, 800V, 1000V, 1500V, 6kV or e.g. lOkV, and currents from e.g. 16A, 32A or 64A, to several hundreds, e.g. 100A, 200A or 500A, or even thousands, e.g. 1000A to 4000A. By local connecting busbar is referred to busbars for local connections inside such a high-power electrical system, e.g. contained inside an electrical cabinet housing a power converter, inverter, transformer, generator, electric motor, breaker, high-power battery system, battery charger, or similar power systems, possibly including capacitors, reactors or inductors, power resistors, dump loads, etc.

[0203] Non-limiting examples of such electrical installations / systems include energy facilities such as grid components such as substations with grid support, voltage regulation, power to x plants, etc., energy generating systems such as wind turbines, wind farms, solar plants, etc., electric installations in a private homes and industry, industrial machines, household appliances, etc. and means for transportation such asairplanes, heavy duty vehicles, light duty vehicles such as automobiles, trains, ships, etc.

[0204] In a high-power electric system, the busbars may be spaced apart and / or isolated from each other with greater distances than what is possible e.g. in an electrical motor. Further, the cross-sectional area of a current path through a busbar according to the present invention is larger than the cross-sectional area of e.g. a winding of an electric motor. This may be true both with respect to a cross-sectional area at a given point of the busbar and over a distance of e.g. 20cm or 30cm in the longitudinal direction of the busbar and physical dimensions. Busbars of a high-power installation or system typically require fastened to a structure comprising the system for every 25- 35cm. Fastening may be achieved with bolts screwed into a support structure such as an electric cabinet or by clamping to the support structure. The busbars need to be electrically insulated from the support structure. In such high-power installations where the primary aim of conductors is to distribute electric energy to components, the magnetic field around a busbar of the present invention is not as important as it is e.g. around a winding of an electrical motor. Thus, since the magnetic field is not the main purpose for manufacturing the electrical busbar for a high-power installation the busbar is typically not designed to have a certain magnetic field when conducting current.

[0205] Manufacturing a high-power electrical local connecting busbar by an additive manufacturing process is advantageous in that additive manufacturing is suitable for manufacturing complex shapes and is thus advantageous to employ for manufacturing of electrical busbars where these are used in narrow spaces such as in an electrical cabinet. Particularly, geometrical features of the electrical busbar, such as individual conductor branches, outgrowths, recesses, internal structures, etc. may be directly manufactured additively. Thus, using additive manufacturing for manufacturing an electrical busbar of a high-power converter or other high-power appliance is advantageous since it may permit tailoring the geometry of the electrical busbar to the conditions / design of the high-power converter and / or the electrical cabinet comprising the high-power converter or appliance.

[0206] Hence, a converter or other appliance according to the present invention comprising an at least partly insulated electrical busbar manufactured by an additive manufacturing process is advantageous in that weight and cost of materials may be reduced due to less material being used for the electrical busbars. Further, cooling of the converter or appliance is improved in that surface area of the electrical busbar can be increased and the electrical busbar can be manufactured with internal cooling channels. Further, assembling of the converter or appliance may be faster due to a reduced number of connections of electrical busbars and to more flexible electrical busbars compared to known busbars. These effects may further all contribute to a more compact design of a power converter or other appliance.

[0207] Further, the electrical busbar may be designed to improve airflow from an air inlet to an air outlet of an electric cabinet. In fact, the electrical busbar may be designed with a geometry that is guiding air flow or other cooling fluid flow in a predetermined direction. A predetermined direction may be towards a heat sink, a connection between busbar and component, an opening to an internal channel of the busbar, etc.

[0208] The invention relates to an electrical system comprising one or more electrical components connected to one or more electrical conductors, at least one of the electrical conductors being an electrical busbar at least partly manufactured by additive manufacturing to comprise at least one auxiliary function region.

[0209] Electrical systems comprise electrical components connected to conductors between the components and / or between the components and a power supply or an output. Advantageously, the present invention provides for an electrical busbar serving the purpose of electrical connection, while further featuring auxiliary functions of the busbar created by means of additive manufacturing. Instead of a typical busbar formed by an elongated solid block of copper or aluminum, or by braided or laminated copper strands for flexibility, the present invention may significantly improve the flexibility options and achieve further auxiliary functions as described herein, due to additive manufacturing.

[0210] The properties and features of the electrical busbar of the electrical system correspond to the above description of an electrical busbar of the invention and are further elaborated herein.

[0211] As described in more detail above and below, possible advantageous auxiliary functions of the auxiliary function region may comprise one or more of improved heat transfer, electrical insulation, flexibility, mechanical support or mounting options, cooling fluid flow guiding, reduced material consumption and weight, etc., all of which individually or in various combinations may be highly advantageous when implemented in an electrical system having challenges like fitting several electrical components into as small a space as possible, and providing individual electrical connections between the components and system inputs and outputs with required safety clearances and / or insulation, and ensuring sufficient cooling to maintain system efficiency and avoid damages and breakdowns.

[0212] In an embodiment the electrical system is a high-power electrical system and the electrical busbar is a high-power electrical local connecting busbar.

[0213] High-power electrical systems and high-power electrical local connecting busbars are described above, and the auxiliary function region of the electric busbar is particularly advantageous in such a configuration, where traditional busbars suffer from problematic heat transfer due to high currents, high rigidity due to large cross sections, etc.

[0214] In an embodiment the electrical busbar is the electrical busbar according to any of the above described busbar embodiments.

[0215] In an embodiment the electrical system is comprised in an electrical cabinet or panel.

[0216] In an embodiment the electrical system comprises a power converter, such as an AC -DC converter, a DC-AC inverter, an AC-DC-AC converter, a frequency control driver, a battery charger, etc.

[0217] In an embodiment at least one of the one or more electrical components is a power module, preferably a switch mode power module, such as an insulated-gate bipolar transistor IGBT power module or a metal-oxide-semiconductor field-effect transistor MOSFET power module, etc.

[0218] Power modules, in particular switch mode power modules, are highly useful in converter applications of all sorts. MOSFET power modules may be preferably for high frequency switching, but have lower power capability than IGBT power modules. Conversely, IGBT power modules are highly advantageous for high-power, lower switching frequency applications.

[0219] In an embodiment the electrical system is a three-phase electrical system.

[0220] In an embodiment the electrical system comprises at least three of said electrical busbar.The drawings

[0221] Various embodiments of the invention will in the following be described with reference to the drawings where figs, la-lc illustrate various concepts of busbars with auxiliary function regions according to embodiments of the present invention, fig. 2 illustrates a method of manufacturing a busbar with an auxiliary function region, figs. 3a - 3b illustrate a perspective view and a cross section of a partial busbar according to an embodiment of the invention, fig. 4 illustrates a non-limiting, simplified example of a dual-material additive manufacturing equipment, fig. 5 illustrates a multi-phase electric busbar according to an embodiment of the invention, figs. 6a-6b illustrate two perspective views of a busbar with multiple auxiliary function regions according to an embodiment of the invention, fig. 7 illustrates an embodiment of an electrical busbar with auxiliary function regions according to the invention, fig. 8 illustrates an embodiment of a separate additive manufacturing of auxiliary function regions, figs. 9a-9b illustrate a projection of an electrical system being a power converter, and a detail view of a power module with busbars of an embodiment of the invention, fig. 10 illustrates a busbar 1 of the invention with an internal cooling fluid channel, and figs. 11-12 illustrate further embodiments of busbar with auxiliary function regions.Detailed description

[0222] Fig. la - 1c illustrates various concepts of busbars 1 with auxiliary function regions according to embodiments of the present invention. Fig. la illustrates an electrical busbar 1 having a twisted geometry / design. The electrical busbar 1 comprises a first end 2 and a second end 3, where the second end 3 being distal to the first end 2 and spaced apart from each other by a middle segment 4.

[0223] The middle section 4 in this particular embodiment comprises a plurality of conductor branches 5. In this particular embodiment the individual conductor branches are spaced apart by air gaps 6 both in the longitudinal and 6a transversal direction 6b of the electrical busbar 1. This twisted design of the conductor branches adds flexibility to the busbar 1 and thus the ability to absorb vibrations. Further, the design is lightweight and easy to mount.

[0224] In this particular embodiment, the first end 2 comprises a first terminal 7 and the second end 3 comprises a second terminal 8. The first and second terminals 7, 8 may comprise one or more terminal holes 10 for connecting the electrical busbar 1 to other electrical components. The electrical busbar 1 is configured to support conductance of an electric current between the first and second terminals 7, 8.

[0225] Each of these two terminals 7, 8 may, via terminal holes 10, clamps, plugs or other electrical connection means, for example be galvanically coupled to terminals, busbars, components (such as breakers, contactors, power modules, reactors, etc.) and other electrical busbars according to the present invention, etc. of an electrical installation. Typically, the electrical busbar 1 and thus the terminals, busbars, components, etc. to which it may be connected would be comprised by an electric box1.e. located inside an enclosure such as a panel, cabinet, etc.

[0226] In various embodiments, the electrical busbar 1 may have several first ends2, several second ends 3, several first terminals 7, and / or several second terminals 8.

[0227] The middle segment 4, which in this embodiment comprises the plurality of conductor branches 5, may also be considered an auxiliary function region 70 of thebusbar 1. Besides the main purpose of the electrical busbar 1 to support conductance of current between the two terminals 7, 8, the present invention advantageously provides for further auxiliary functions of the busbar 1. The auxiliary function is achieved by means of additive manufacturing, also referred to as 3D-printing.

[0228] In the embodiment of fig. la, the auxiliary function region 70, is also a heat transfer region 71. The airy design of multiple conductor branches 5 with mutual airgaps 6 instead of a solid busbar may have better heat dissipation due to larger surface and better air cooling possibilities.

[0229] The auxiliary function region 70 is further a flexible region 73. The conductor branches 5 allows for slightly bending and twisting the busbar 1, thereby facilitating installation and mitigation of vibrations.

[0230] Further, the auxiliary function region 70, is also a reduced material region 77, as a larger combined cross section area would be required with a solid design due to heat buildup, etc.

[0231] Fig. lb illustrates an electrical busbar 1 having a web-like or lattice-like geometry / design. As the electrical busbar 1 illustrated in fig. la, the electrical busbar illustrated in fig. lb comprises a first end 2 and a second end 3 separated by a middle section 4. The first end 2 may comprise a first terminal 7 and the second end 3 may comprise a second terminal 8. The first and second terminals 7, 8 may comprise one or more terminal holes 10 for connecting the electrical busbar 1 to other electrical components.

[0232] Between the two terminals 7, 8 conductor branches 5 in a web-like structure extend (only one is highlighted). These conductor branches meet and branch off in a plurality of intersection points 9. Note that the first and second ends 2, 3 are also partly manufactured as a web-like design as the middle segment 4. Also note, that the first and second terminals 7, 8 comprise more than one terminal hole 10. The terminal holes 10 of the terminals 7, 8 is made in a part of the ends 2, 3 which has non-perforated surface i.e. a surface different from the web-like surface of e.g. the middle segment 4 of the electrical busbar in this particular embodiment. The planar contact surface ofthe terminals 7, 8 around the terminal holes 10 is preferred to provide a connection surface to another flat surface with as little resistance as possible and sufficiently strong contact surface between bolt / nut and electrical busbar 1.

[0233] The busbar of fig. lb comprises auxiliary function regions 70 as introduced above. Besides the main purpose of the electrical busbar 1 to support conductance of current between the two terminals 7, 8, this busbar also provides for further auxiliary functions. The auxiliary function is achieved by means of additive manufacturing, also referred to as 3D-printing.

[0234] At the first end 2 is illustrated 6 first terminals 7, the larger through holes. However, the smaller through hole in the middle is a mounting hole for securing the busbar mechanically to an electrical component. Hence, this through hole is an auxiliary function region, in particular a mounting region 75.

[0235] Most of the airy busbar 1 further serves at least three auxiliary function with most of its extent. Hence, the entire web-like structure may be considered an auxiliary function region 1, in particular a heat transfer region 71 and a reduced material region 77, as described above.

[0236] Fig 1c illustrate an electrical busbar having a bionic geometry / design. As the electrical busbar 1 illustrated in fig. la and lb, the electrical busbar illustrated in fig. 1c comprises a first end 2 and a second end 3 separated by a middle section 4. The first end 2 may comprise a first terminal 7 and the second end 3 may comprise a second terminal 8. The first and second terminals 7, 8 may comprise one or more terminal holes 10 for connecting the electrical busbar 1 to other electrical components.

[0237] The middle segment 4 in this embodiment is of a so-called bionic design, preferably achieved as a computer generated design. Such computer-generated design is provided based on input to a computer program controlling an additive manufacturing machine / process or able to export data to a controller of an additive manufacturing machine / process such as from a user or another computer. Input may include dimension, maximum current to be conducted, required strength, maximum deflection (elastic or plastic), etc. As the electrical busbar illustrated in fig. lb, theelectrical busbar of this particular embodiment comprises both longitudinal conductor branches 5a and transversal conductor branches 5b. It is noted, that together the conductor branches 5a, 5b forms a transversal conductor branch outgrowth i.e. if seen in a side view, the electrical busbar 1 of fig. 1c would be thicker at the middle section 4 than at the ends 2, 3. The conductor branches 5 are spaced apart in space by air gaps 6 in both X (6a), Y (6b) and Z (6c) directions. Further note, that the terminals 7, 8 are designed with a planar surface to obtain best possible contact with a component having a planar surface, to which the electrical busbar 1 is to be connected to, such as clamped against, via for example bolt and nuts. Also note, that independent from the geometry of the ends 2,3, the terminals 7,8 are aligned / raised so that the contact surface for, e.g., all three terminals 7 are in the same plane.

[0238] The above embodiments of an electrical busbar 1 all feature airy geometries having air gaps 5 between conductor branches 6. The electrical busbar 1 of the present invention may in other embodiments feature other airy geometries such as web-like, gyroid-like, lattice-like, etc., as described in more detail herein, which in various embodiments may provide improved cooling, reduced material consumption, improved flexibility, and / or other advantages described in more detail herein. The term ‘-like’ is used in connection with gyroid-like, lattice-like, etc., to emphasize that it is an airy geometry resembling the named structure, rather than a specific systematic structure, that is relevant in preferred embodiments of the invention.

[0239] The busbar of fig. 1c comprises auxiliary function regions 70 as introduced above. Besides the main purpose of the electrical busbar 1 to support conductance of current between the two terminals 7, 8, this busbar also provides for further auxiliary functions. The auxiliary function is achieved by means of additive manufacturing, also referred to as 3D-printing.

[0240] At least the bionic design of the middle segment 4 serves as auxiliary function region 70, particularly as heat transfer region 71 and as reduced material region 77, as described above.

[0241] It should be noted that the three different designs of electrical busbars of the present invention illustrated in fig. la-lc is not limiting for the designs or geometries or structures that is possible to manufacture according to the present invention. Other designs that are possible to represent digitally and transfer to an additive manufacturing device and thus manufacture by additive manufacturing is considered to fall with the scope of the present invention. This includes designs having plane surfaces with internal ducts, manufactured by different materials, manufactures with protrusions or recesses, manufactured to have auxiliary functions beside conducting current, etc. Particularly, high-power conductors are advantageous to manufacture according to the present invention.

[0242] Note that embodiment of the invention, such as the above-described electrical busbars, may comprise further terminals 7, 8 between the ends 2, 3, which are not illustrated. Also note, that a plurality of the illustrated electrical busbars 1 may be connected to form a complete electrical busbar. In this case the first and second end 2, 3, is referred to as the ends of the complete electrical busbar which may comprise terminals 7,8 and e.g. terminal holes 10 for connecting the complete electrical busbar to other components. Between these first and second ends 2, 3 of the complete electrical busbar, terminals 7, 8 of a plurality of electrical busbars as illustrated may be connected.

[0243] Further, embodiment of the invention, such as the above-described electrical busbars, may comprise additional or alternative auxiliary function regions, for example heat transfer regions, electrically insulated regions, flexible regions, mechanical support regions, mounting regions, flow guiding regions, reduced material regions, etc.

[0244] The cross-sectional area of the busbar / conductor branches can be exploited to its full potential in an electrical busbar of the present invention. The busbar is designed and manufactured to have a cross-sectional area that is able to comply with requirements to current to be conducted without have excess of material used. The design of the present busbar may not have surplus material which is not used for conducting current when nominal current is supplied e.g. to a 1400A power module.If extra material is used, this is used for cooling the busbar or a safety margin. The amount of such extra material can be determined relatively precise by the software which is used to design the busbar. As a rule of thumb, the larger surface for cooling, the higher amps is possible to conduct. The design software may be able to put weight on amps, cooling properties (cooling medium, surface, etc.), frequency of the current when designing the geometry of the busbar, etc. when designing the busbar. Accordingly, a conducting cross-sectional area of a busbar as illustrate in fig lb may be 80mm2 may in certain embodiments be sufficient to conduct a current of 1300 A due to the airy design allowing a very advantageous cooling. In fact, tests have shown that the temperature of a conventional massive busbar with a conducting cross- sectional area of 516mm2 conducting 1300A increases to a temperature where neighboring components of plastic is in risk of melting.

[0245] Hence, it should be noted that the busbar may be designed and subsequently manufactured so that a percentage of the cross-sectional area of the electrical busbar e.g., above 80% such as between 90% and 100% is used to conduct current during normal operation. This is in contrary to known massive busbars that does not exploit the material in its center to conductor current. This is at least true for most frequencies of currents conducted in high-power systems including renewable systems, vehicles and the like.

[0246] The high percentage of utilization of cross-sectional area for conducting current compared to known massive busbar is possible to obtain in that the busbar of the present invention and thus the individual conductor branches because they are designed with a cross-sectional area that sums up to be able to conduct a current of a given frequency. Further, the material reduction is also made possible because of the possibility of cooling also inside the busbar. In fact, a conductor branch may along most of its length, in some embodiments along all of its length, be cooled from all angles i.e. a 360° cooling of the conductor branches is possible.

[0247] As mentioned, a busbar of the present invention may form an airy geometry which depending on the kind of airiness may not facilitate a secure or robust platform or structure for fastening the conductor e.g. to the electric cabinet. Accordingly, inproximity of through-holes for fastening the conductor or through-holes, e.g. terminal holes, for connecting the conductor to components or other conductors, the geometry of the busbar may not be airy. Preferably, around a through-hole the density of the conductor is higher or more concentrated to form an, e.g., planar surface and thereby provide the best possible preconditions for conducting current between two parts of a joint and to distribute the force required to fastening a conductor in the joint or to a support structure. Hence, a through-hole may be designed as a cylinder through which a bolt may pass through and with planar upper and lower parts extending from the periphery of the cylinder to facilitate the force and / or current distribution in the joint. Other mounting and / or terminal points may be preferred in some embodiments, such as flanges, protrusions, plugs or sockets, etc., with or without through-holes, but with the same consideration of ensuring sufficient robustness and stability of the electrical busbar for the intended mounting or connection method. The through-holes could be 6mm, 8mm, 10mm or 12mm in diameter.

[0248] It should be mentioned that terminals for electrical connection may be positioned at or between the ends of an electrical busbar. Thus, in principle, a busbar may be manufactured by an additive manufacturing process and when the first end and first part of the middle segment is manufactured these may be rolled onto a conductor holder as the middle segment is continued to be manufactured. Alternative, the busbar is guided out of the printing areas e.g. by a conveyer belt as the busbar is manufactured. This may result in a long busbar with two ends. Either during manufacturing or after, terminals may be made in the busbar and also after manufacturing, the busbar may be cut into desired lengths. In this way, terminals may be manufactured or provided either at the ends or between the ends of the busbar.

[0249] The term monolithic is in this description used to describe the geometry or structure of an electrical busbar according to the present invention. Such busbar is preferably manufactured by an additive manufacturing process and thereby, it is manufactured as a single piece, unit or block from one end to the other or at least one end and a middle segment is manufacture as a single piece. Such busbar may thus be formed from a single material as a single piece, unit or block where its one or moreends are monolithically formed with a middle segment connecting the one or more ends i.e. monolithically formed should be understood as made in one continuous process with no need for additionally adding one part to another I.e. one or more ends are manufactured together with the middle segment as one unit with no connections such as welding, soldering, or by any clamping or fastening means, except for the type of micro binding intrinsic to the particular additive manufacturing technology utilized, such as, e.g., layer-by-layer melting, sintering, liquid binding, spraying, etc. With this said, it should be mentioned, that it is possible to add additional elements such as terminals, cooling fins, etc in a post manufacturing process e.g., by a cold spray process.

[0250] Put in another way a busbar of the present invention is the result of a process forming the busbar in one structure, a busbar composed of an electrically conductive material without joints or seams and thus constituting a busbar as a rigid whole exhibiting a rigidly fixed uniformity. To such busbar it is possible to connect additional conductors via terminals and thereby branch off one current path to two or more current paths or vice versa.

[0251] It should be mentioned that the busbar may be manufactured from more than one type of material. In this situation, the busbar could be said to be polylithic. The term polylithic should in this context be understood as a geometry or structure of an electrical busbar that is manufactured in one piece as a monolithic structure, as described above, where the busbar is manufactured from two or more materials. Hence, a polylithic busbar of the present invention is a conductor resulting from a process forming the busbar in one structure where the process is using two or more different materials. Such two or more materials may be a combination of electrical conductive or non-conductive materials.

[0252] In most embodiments, the electrical busbar 1 is designed to comply with high voltages i.e. voltages above 24V such as 110V, 230V, 400V, 690V, 1000V, 1500V and up to kV systems, just to mention a few voltage levels of an electrical installation in which the electrical busbar 1 of the present invention would be suitable. In terms of current, an electrical busbar 1 according to the present invention may be designed toconduct several hundreds of amps (16, 32, 64, and so on up to 100, 200 and so on up to e.g. 900 A) up to a couple of thousand amps (1000A-3000A). Electrical busbars may be designed to conduct higher currents than 3000 A e.g. by improving cooling of the busbar in combination with an increased cross-sectional area of the conducting part of the busbar.

[0253] Mentioning these voltages, it should be noted, that in principle there are no lower limits as to the voltage and current. I.e., versions of the electrical busbar may be designed to be used in, e.g., 3.3V, 5V, 9V, 12V, 15V, 20V, 24V or 48V systems, such as USB power delivery PD systems, conducting currents below, e.g., 10A, such as 5A, 3 A, 2.4A, or 2A just to mention a few examples.

[0254] Thus, the electrical busbar 1 of the present invention is suitable for use in almost any type of electrical installation. This includes everything from low voltage to high voltage AC and or DC systems where transfer / conducting of current or communication signals is needed.

[0255] The present invention is particularly advantageous for electrical busbars designed for high-power electrical systems, e.g. from lOkW and up, such as 22kW, 50kW, HOkW, 150kW, 225kW, 300kW, 350kW, 500kW, 800kW, 1MW, 2MW, 3 MW, or even higher, such as e.g. 5MW or 10MW systems, with voltages of e.g. 110V, 230V, 400V, 690V, 800V, 1000V, 1500V, 6kV or e.g. lOkV, and currents from e.g. 16A, 32A or 64A, to several hundreds, e.g. 100A, 200A or 500A, or even thousands, e.g. 1000A to 4000A. By local connecting busbar is referred to busbars for local connections inside such a high-power electrical system, e.g. contained inside an electrical cabinet housing a power converter, inverter, transformer, generator, electric motor, breaker, high-power battery system, battery charger, or similar power systems, possibly including capacitors, reactors or inductors, power resistors, dump loads, etc. A system, component or busbar may be categorized as a high-power system, component or busbar if it is operating at currents in the range of 800-1000A or higher.

[0256] Non-limiting examples of such electrical installations / systems include energy facilities such as grid components such as substations with grid support, voltageregulation, power to x plants, etc., energy generating systems such as wind turbines, wind farms, solar plants, etc., electric installations in a private homes and industry, industrial machines, household appliances, etc. and means for transportation such as airplanes, heavy duty vehicles, light duty vehicles such as automobiles, trains, ships, etc.

[0257] Accordingly, the electrical busbar may be a high-power electric conductor of a high-power electric system. In a high-power electric system, conductors may be spaced apart and / or isolated from each other with greater distances than what is possible e.g. in an electrical motor. This distance is referred to as a safety clearance and the size of it depends on the voltage differences in the system. Thus, when depending on air as isolator between an otherwise non-isolated busbar / conductor and another conductor or structure of conductive material such as a metal cabinet, the distances must be taken into account in compliance with safety regulations. It should be mentioned that air quality / pollution degree, such as humidity and particle content, may also be relevant for the distance of the safety clearance. In case a busbar is used in a high-voltage system the surface is manufactured to reduce field concentrations.

[0258] Further, the cross-sectional area of a current path through a busbar according to the present invention is larger than the cross-sectional area of e.g. a winding of an electric motor. This may be true both with respect to a cross-sectional area at a given point of the busbar and over a distance of e.g. 20cm or 30cm in the longitudinal direction of the busbar and physical dimensions.

[0259] Current conducting busbars of a high-power installation or system is typically fastened to a structure comprising the system for every 25-35cm. If the current is conducted by cables, the distance between cable fasteners may be even smaller. The fastening may be made by screwing bolts into a support structure such as an electric cabinet or by screwing clamps to the support structure which is then closed and thereby fastening the cable / busbar. The conducting cables / busbars are of course insulated from the support structure.

[0260] In such high-power installations where the primary aim of busbars is to distribute electric energy to components, the magnetic field around a busbar of the present invention is not as important as it is e.g. around a winding of an electrical motor. Thus, since the magnetic field is not the main purpose for manufacturing the electrical busbar for a high-power installation the busbar is typically not designed to have a certain magnetic field when conducting current.

[0261] Further, again comparing to e.g. a winding of an electrical motor, a busbar of the present invention would as a general rule be designed with a surface area that is as large as possible to optimize the possible advantages of the invention as described herein. Depending on the purpose of the busbar, the surface may for example be designed for conducting current, conducting current and heat dissipation or heat dissipation. Thus, even though all portions of a busbar of the invention may comprise an electric conductive material, not all portions are necessarily used for conducting current through the busbar. In general, the available area around a busbar is exploited to expand the surface of the busbar for one of, for example, the heat dissipation or current conducting purposes, or other described purposes such as improved flexibility, reduced material consumption, air guidance, etc. The available area is limited by safety clearances to other conductors of different phases having different voltage levels, grounded structures such as elements of an electric cabinet, etc.

[0262] An example of a portion of a busbar that is primarily used for non-conducting purposes such as heat dissipation or air guidance, is an outgrowth from the surface of the busbar which is not connected at the distal end of where it is growing from the surface of the busbar. Such outgrowth or protrusion may for heat dissipation purposes preferably comprise some kind of bionic design with airgaps between branches, possibly with a continuous surface towards a direction of air flow for air guidance purposes. Such portions would be referred to as conductor branches if these were part of the middle segment conducting current form one end to the other. Such outgrowth may in principle take any form or geometry exploiting the free space around the area as long as safety clearance distances are maintained. In such examples, the fraction ofcurrent conducted by the surface area of the outgrowing busbar portion is very small if not zero.

[0263] An example of a portion of a busbar that is only used for conducting a current may in principle not be possible in that heat dissipates even from a solid block and a planar surface. What should be understood by a portion of a busbar primarily used for conducting current, is a varying structure or geometry for a middle segment of the busbar between the first and second terminals. When space is narrowed between components in an electrical system, if other conductors are to be passed, if the busbar has to pass through a current sensor or bushing, etc., the surface area of that particular portion of a busbar middle segment may be reduced to comply with available space, thereby typically increasing the busbar density to achieve a narrower outer dimension. In this example, at this particular portion of the busbar, the current conducting portion of the surface area of the busbar becomes high; possibly so high that a hot spot is created where additional cooling is required to continue to maintain a certain current conduction capacity. Hence, this is an example which may benefit from a combination of the conducting portion with an outgrowth portion, as described above, e.g. on each side of the narrowed part of the busbar. In this way, heat generated at the narrow space can be dissipated via the nearby outgrowths, e.g. further in combination with internal cooling channels.

[0264] An example of a portion of a busbar that is used for both heat dissipation and current conduction is a middle part between the terminals, with an airy design or geometry. In such example, the surface areas having the main purpose of dissipating heat and conducting current, respectively, may be the same or close to be the same. This is due to a geometry comprising conductor branches spaced apart from each other so that a flow of cooling air may pass freely by each conductor branch, i.e., through air gaps defined by the conductor branches. In this example the current conducting surface area is large compared to traditional conductors / busbars and windings e.g. of an electric motor. Another difference between a motor winding and a busbar of the present invention may be found in the circumference of the busbar. The limited space inside a motor obviously limits the circumference of the winding. This is not the caseto the same extent e.g. in an electrical cabinet comprising a busbar of the present invention. More space is available and thus the circumference can be made larger leading to an airy design with airgaps for increased cooling. Further, the cross- sectional area of the individual conductor branches of a busbar according to the present invention is often lower than the cross-sectional area of a motor winding.

[0265] As mentioned, the electrical busbar 1 may comprise first and second ends 2, 3 spaced apart by a middle segment 4. One complete or final electrical busbar may comprise a plurality of interconnected electrical busbars 1 of the types illustrated / described above. In such embodiment the illustrated electrical busbars may be used as sections of the final or complete electrical busbar. Thus, a final or complete electrical busbar may comprise first and second ends 2, 3, with a plurality of first and second terminals 7, 8 at the ends or between them, e.g. with terminal holes 10 for connecting a plurality of the illustrated / described electrical busbars to form the final or complete electrical busbar.

[0266] The terminals 7, 8 may comprise one or more terminal holes 10 or other structures for connecting the electrical busbar 1 to other electrical busbars such as busbars, cables or the above-described electrical busbars, electrical components such as breakers, power modules, batteries, etc.

[0267] Alternatively, in an embodiment, one or both of the terminals 7, 8 of the electrical busbar 1 form part of an electrical component as an alternative to being provided as freely connectable locations at the busbar 1.

[0268] A terminal 7, 8 may in a simple embodiment comprise a terminal hole 10 through the terminal 7, 8. Via such hole, a bolt can go through and continue through a component with which the electrical busbar 1 is to be connected. The electrical busbar and the component are then clamped together via a nut and the bolt.

[0269] Alternatively, a terminal 7, 8 may be a click terminal that is either designed to receive a click part form a component to which the electrical busbar is the be connected or designed with a click part that is to be inserted into such other components.

[0270] Alternatively, a terminal 7, 8 at an end 2, 3 of the electrical busbar may be manufactured with a threat which when engaging with a bolt is able to assist in clamping a component to the electrical busbar 1.

[0271] Further, it should be noted, that an electrical busbar as illustrated or a complete electrical busbar comprising a plurality of electrical busbars such as the above described may have more than one first end 2 or more than one second end 3. Hence, one end of an electrical busbar 1 may branch off in e.g. three terminals each with a terminal hole. This may be advantageous in that the geometry of the electrical busbar is then designed specifically to the component to which it is to be connected. Branching off the ends into several terminals may also improve heat dissipation capacity at the possibly denser terminal portions, improve electrical connection between the busbar and components, and avoid additional connection pieces or shunts in order to connect adjacent components to a common busbar.

[0272] The middle segment 4 may comprise one, but preferably a plurality of conductor branches 5. The conductor branches 5, like the end segments 2, 3, are at least partly made of an electric conductive material such as copper or aluminium or alloys thereof, enabling the electrical busbar 1 to conduct a current between its terminals 7, 8. The design of the conductor branch(es) 5 may be optimized according to a specific purpose such as cooling, material consumption, flexibility (control in a particular direction), footprint, etc. Thus, depending on which parameter(s) the electrical busbar 1 is designed according to, the conductor branches may be designed as longitudinal cylinders (or other geometries such as oval, square, etc.), web, bionic, gyroid-like design, lattice-like design, branch-like design, or sponge-like design, coil or solenoidal designs, spirals, etc.

[0273] Thus, the electrical busbar may have a perforated surface, a non-perf orated surface, a massive structure or a structure with internal channels optimizing the electrical busbar according to skin-effect and cooling, etc.

[0274] Two or more conductor branches 5 may meet in an intersection point 9 and two or more conductor branches 5 may branch off from an intersection point 9. Thishas the effect, that an electrical busbar is established that maintain a desired strength (determined yield point) with a minimum of material. Among others, this may reduce the cost of the electrically conductive material and reduce the weight of the busbar. It should be mentioned that two conductor branches meeting in the intersection point 9 may be the same two conductor branches leaving that intersection point 9. Alternatively, two other conductor branches may leave the intersection point, however this may be a question of definition of a conductor branch. Further one conductor branch may branch off to a plurality of conductor branches and a plurality of conductor branches may meet and form a lower number of conductor branches.

[0275] Further, it should be mentioned that the electrical busbar 1 may be designed as a plurality of electrical busbars, e.g. as a combination of three phase conductors or as a wire harness or printed circuit board traces of a printed circuit board used for mounting in an electric panel.

[0276] At least a first end 2 and a middle segment 4, but preferably also the second end 3, of the electrical busbar 1 of the present invention are monolithically formed, since they are manufacturing from a single bulk of material, which is machined to provide the electrical busbar 1. Here bulk of material should be understood as the material such as electrically conductive material of which the electrical busbar 1 is made, e.g. a solid, powder, liquid, wire, etc. Here machined should be understood as manufactured by additive manufacturing, i.e. the electrical busbar 1 is made in one piece without any mechanical connections of the first end 2, second end 3 and middle segment 4.

[0277] Note that more than one type of material, e.g. two bulks of material, may be used to manufacture the electrical busbar. One of such two or more bulks of material may be electrically non-conductive.

[0278] Note that in some embodiments it may be necessary to manufacture the electrical busbar in more than one piece. In this situation the electrical busbar may be referred to as a complete or final electrical busbar which comprises a plurality of electrical busbars 1 as described above. This may be the case e.g. if the electricalbusbar needs to be mounted in a location where it cannot be inserted unless the electrical busbar is separated in two or more pieces or if the complete electrical busbar has to be larger than what is possible to manufacture by additive manufacturing. In such situation, terminals of two electrical busbars are connected, extending the length of the middle section and thereby the current path between the first end 2 and the second end 3 and thus of the complete electrical busbar. Such connection may be prepared by designing terminal holes in the busbar where, e.g., fish plates or other joints may be fastened and thereby connecting the two middle segments.

[0279] It should be noted that the electrical busbar 1 may have a non-uniform geometry / design. The design / geometry may take any machinable / printable shape. Such shape may be optimized according to conducting current (skin effect), cooling, guidance of flow of cooling fluid, other components in a panel, resistance, power loss or current displacements, etc.

[0280] In a particular embodiment, the electrical busbar 1 may have a non-uniform diameter (measured in a transversal direction) along the lengthwise direction. A well- defined diameter may nevertheless be determined e.g. at a transversal plane at which that electrical busbar 1 has its smallest diameter.

[0281] Moreover, in an embodiment of the invention the perimeter length of the electrical busbar 1 or its conductor branch(es) 5 may vary in transversal planes at different positions in the lengthwise direction of the electrical busbar 1. The perimeter length of a given part of the middle segment may simply be measured as the sum of all lengths of perimeters of branches in a given transversal plane. Hence, the perimeter length at a given part may thus be the length of the perimeter of conductor branches measured across / perpendicular to the longitudinal direction of the electrical busbar at that part. A part of a busbar may also be referred to as a portion of a busbar and should be understood as a reference to a specific portion of the busbar such as an end or middle segment.

[0282] The perimeter length of the conductor branches 5 may be the sum of lengths of perimeters of all individual conductor branches 5. As one conductor branch maysplit from a stem to two or more twigs, i.e. branches of a branch, the perimeter at one part of the conductor branch may be different from one part (e.g. a twig part) to another part (e.g. a stem part). Hence, the sum of lengths of perimeters of the conductor branches may be the sum of all individual twigs or of all the individual stems. In case of multiple different possible perimeter lengths for the busbar parts along the length of the electrical busbar, the smallest perimeter length may preferably be used in calculation of current conduction capability of the electrical busbar 1.

[0283] In the same way, the cross-sectional area of an electrical busbar at a given part is measured as the sum of the cross-sectional area of all conductor branches at a given part along the length of the electrical busbar. The cross-sections at that part should be measured perpendicular to the longitudinal direction of the electrical busbar.

[0284] In an embodiment, the electrical busbar 1 may comprise one or more cooling channels, where the cooling channel may be placed inside the one or more conductor branches, transversally and / or longitudinally.

[0285] The manufacturing of the electrical busbar 1 with auxiliary function region 70 may be done by an additive manufacturing process. Such manufacturing process may be based on, but not limited to, one of the following additive manufacturing processes: 3D printing, layer by layer printing, Wire Arc Additive Manufacturing, Fused Deposition Modeling FDM, Direct Energy Deposition, Direct Metal Deposition, sintering based processes, laser based processes, for example Powder Bed Fusion PBF, such as selective laser melting SLM or selective laser sintering SLS, cold spray additive manufacturing CSAM, binder jetting or binder jet 3D printing, etc. It should be mentioned that the actual additive manufacturing process used to print or build the electrical busbar 1 may not be important as long as the material of which the electrical busbar is built is an electrically conductive material.

[0286] Fig. 2 illustrates method steps for machining an electrical busbar 1 according to an embodiment of the invention. The particular method relates to forming an electrical busbar with two ends or two terminals, namely a first end / terminal and asecond end / terminal via a middle segment, but may be used for producing any kind of electrical busbar of the present invention.

[0287] It should be mentioned that this may include manufacturing both ends and the middle segment in one process. Hence, with additive manufacturing along the longitudinal direction of the busbar, the method may start by manufacturing, such as printing, one end, then a transition to the middle segment, possibly one or more conductor branches, then the middle segment, then a transition to the second end and finally the second end. In another embodiment, the additive manufacturing occurs transversal to the busbar’s longitudinal direction, thereby for example manufacturing portions of both ends and the middle segment simultaneously, increasing the cross section with each applied layer. In another embodiment, the additive manufacturing is radial, or even arbitrary, to the busbar’s longitudinal direction, for example using cold spraying CSAM or Fused Deposition Modeling FDM while rotating or freely moving either the busbar unit being built or the nozzle, or both. Preferably, the mentioned segments are manufactured in one process, e.g. as one segment is manufactured, the next segment is being manufactured. A transition part may be made between such two segments which may start or include the first segment. Similarly, the second segment may include a transition part or is connected to such transition part.

[0288] It should also be mentioned that the method could in some embodiments comprise manufacturing the middle segment and afterwards connect the end segments. The end segments could be connected while being additive manufactured or could be connected with an additive manufacturing thermal paste or glue after being made. The end segments could also be welded, glued or connected in any other way to the middle segment, e.g. by cold spraying CSAM.

[0289] In an embodiment, the auxiliary function region 70 is added to a provided busbar by additive manufacturing. An appropriate additive manufacturing technology for this may depend on the busbar configuration and the kind of auxiliary function region 70 to be built, in particular the kind of material. Cold spraying additive manufacturing CSAM may be an advantageously be used to add auxiliary function regions 70 to busbars in many different configuration, as also described further below.

[0290] An additional embodiment of the invention could be a manufacturing method that comprises two or more middle segments being additive manufactured. The two or more middle segments could be additive manufactured in the same process with the two end segments to form the electrical busbar. The two or more middle segments could also be additive manufactured separately and connected afterwards to form the electrical busbar.

[0291] The two or more middle segments could be identical or could be two differently shaped or otherwise characterized middle segments depending on where the electrical busbar should be placed in e.g., an electrical cabinet.

[0292] A transition may straightforwardly be defined as a change of size of a layer compared to a previous layer. In this way a transition may be formed as a perpendicular transition between an end segment and a conductor branch of the middle segment. Alternative, subsequent layers may change in cross-sectional area and thus form a transition as a rounded transition which may be advantageous in terms of a reduced resistance for current conducted between the ends of the electrical busbar.

[0293] A monolithic busbar according to the present invention is made from one material. One or more additional materials may be used e.g. as isolation, for heat dissipation, etc. in this case the busbar may be referred to as a polylithic busbar. No matter the number of materials, a busbar produced by additive manufacturing is produced bit-by-bit starting at a first spatial coordinate (x, y, z) and ending at a second spatial coordinate. At least when the busbar is finished the first and second spatial coordinates are electrically / mechanically connected. As mentioned several methods of manufacturing a busbar exists all including some kind of material depositing, joining or soldering to manufacture a busbar in one monolithic form.

[0294] In this document a busbar may be referred to as being manufactured layer- by-layer no matter the additive manufacturing method used. Hence, if a busbar is sliced (no matter in which orientation) and one is looking at the cross-section of the busbar it is easy to imagine that the busbar is manufactured starting with material in first point, then with material in a second point and so on. Since the busbar is volumetric i.e. hasa three dimensional geometry the first point is different from the second and subsequent points at least in one of the spatial X, Y and Z directions / plans. Thus, with reference to the spatial X, Y and Z planes a busbar could be said to be built from a plurality of subsequent layers even though when manufactured all material in one plane such as X=1 and Y=0 and Z=0 is not provided as a one layer or in one layer before material in a next layer (e.g. an X=2 layer) is provided.

[0295] Hence, no matter which of the processes of manufacturing a three- dimensional object such as a busbar that is used, it can be said that the busbar is manufactured layer-by-layer even though some of these manufacturing processes are based on deposited, joined or solidified with material being added together in areas, lines, pointwise, etc. This is because no matter the additive manufacturing process the busbar is manufactured one point after the other. A plurality of points in the same plan (e.g. X=3) is considered one layer also if they are not physically connected in this plane. And when all points of this layer are added, points of the next layer (e.g. X=4) is added to the points in the X=3 layer. As mentioned, a layer may be defined in any of the planes of a spatial Cartesian coordinate system.

[0296] Alternatively, the ends may be separate segments that are connected via the middle segment. The middle segment may be printed, and during the manufacturing of the middle segment it may be attached to the ends such as printed, heated, glued or the like onto the ends. The middle segment may be joined to the ends by means of welding, printing, soldering, etc.

[0297] It should be noted that the ends may comprise terminals for connecting the electrical busbar to other electric parts / conductors / windings of an electric system. Such terminals may be manufactured like the rest of the electrical busbar by additive manufacturing i.e. monolithically formed with the ends.

[0298] In a step SI of this particular method, considering additively manufacturing a busbar in its longitudinal direction from the first end towards the second end, the first end segment and middle segment in the form of conductor branches of a plurality of conductor branches are monolithically formed via individual transitions that may ormay not include rounded connections to shape concavely rounded interior corners between the first end segment and conductor branches of the plurality of conductor branches and to spatially separate conductor branches of said plurality of conductor branches.

[0299] The step of monolithically forming the first end segment and conductor branches may be implemented using various methods, for example methods such as additive manufacturing such as 3D printing, casting, and simply removing of material, via machining, from a bulk metal slab to form conductor branches combined with a first end segment.

[0300] More specifically, a known massive conductor such as a main busbar with a length of e.g. 3-5m may conduct 1-2A per mm2. If the same busbar was made in an airy design and e.g. with an internal cooling, then due to the improved cooling the same 1-2 A per mm2 may be conducted with the same efficiency despite the removal of material. Typical conductor materials such as aluminium and copper have temperature coefficients at approximately 0.4% / deg C. If such busbar is efficiently cooled so that the temperature is e.g. 25 deg C lower compared to a conventional busbar, the resistance is reduced by approximately 10%. Hence approximately 10% of the material can be removed without compromising the losses. Furthermore, in AC busbars the current is not evenly distributed across the conductor volume. Typically, the current density is reduced towards the center of the busbar. Taking such considerations into account can allow for further removal of material without compromising the efficiency of the busbar.

[0301] In a step S2 of the method, the first end segment becomes electrically coupled and mechanically coupled to a second end segment via the middle segment of the electrical busbar formed by the plurality of conductor branches. This may also be monolithically achieved, e.g. by continuing the additive manufacturing, as described in step S 1.

[0302] The coupling of the end segments to the middle segment could also be done by welding, gluing, male / female locking mechanism or any other way that would connect the segments both mechanically and electrically.

[0303] An optional, additional step of the method of manufacturing the busbar of the invention comprises a step prior to the step of additive manufacturing any of the first, second or middle segments. The step prior to manufacturing the electrical busbar is a step where a digital representation of the electrical busbar is designed in a software program, e.g. a 3D CAD software. The step of designing the digital representation of electrical busbar in a software program includes taking the electrical, mechanical, structural, geometry and other aspects of the physical electrical busbar into account. Thus, based on these inputs, e.g. provided by a user of the 3D CAD software, a digital representation of the busbar is provided by the 3D CAD software. When the digital representation of the electrical busbar is complete the additive manufacturing process can be started.

[0304] A further optional step may be applied i.e. a heat treatment to the finalized conductor. A heat treatment may e.g. be 4 hours at 400C and upwards depending on the material. An advantage of heat treatment is that the particles of the manufactured conductor is mutual positioning or merging leading to higher conductivity both thermal and electrical. This is at least true for Aheadd® CPI 20 / 63 aluminium powders and other aluminium-iron-zirconium powder solutions. Such powders may be used in laser powder bed fusion machineries. Using this type of powder and heat treatment may lead to higher thermal stability, thermal conductivity, corrosion performance and surface finishing as well as higher electrical conductivity.

[0305] The middle segment may in principle have any design / geometry, for example providing flexibility thereto allowing the electrical busbar to deform. It may be formed by conductor branches being solid or having internal cavities to reduce the amount of material that is needed to manufacture the electrical busbar. It may be formed by a web or as a hybrid between conductor branches or web just to mention a few possible designs.

[0306] Internal cavities may be used as cooling channels and / or additional surface for conducting high frequency current. Accordingly, the end segments and middle segments may be designed for the particular panel / electric system in which it is used, for a particular type of current to conduct, for having a desired or dual functionality, etc.

[0307] One such functionality, beside the above-mentioned may be as a structural support. Hence, if needed the electrical busbar may be designed to assist in carrying the weight of electric components connected thereto. Hence, its dimensions may be larger than what is needed by it for carrying the required current. Similarly, its geometry may be designed for the combined purpose of mechanical support and electric conductance. This is especially true if such support is flexible / deformable in that it may both assist in supporting and at the same time assist in absorbing vibrations.

[0308] It should be mentioned that the electrical busbar 1 may be manufactured in two or more resolutions. The thicker layer the faster manufacturing. The layer thickness depends on the material and printing apparatus and may vary from a few millimetres to 20um, using some combinations the layer thickness is between 50um and 150um. In case of additive manufacturing resolution may be defined by thickness of the layers of which the electrical busbar is built (another word for machined and processed). A first resolution that is finer i.e. having thinner layer size than a second resolution may be used when manufacturing the interface between the electrical busbar and the part to which it is connected. Such interface may be the part of the terminal that is in contact with the other part. Alternatively, resolution may be determined by material deposition rate, material flow rate, etc. depending on the type of additive manufacturing used.

[0309] To avoid electric losses in connections between two electrical busbars it is preferred that the two parts have mating surfaces, which is most simply achieved by having planar surfaces, but may also be achieved by convex and concave combinations, mortise or finger joints, engaging teeth, cylinder and peg, tongue and groove, slide lock, etc., to further achieve additional advantages, e.g. larger surface area of connection, easier assembly of electrical busbars such as busbars in electricalsystems by self-locking, etc., as long as good electrical connection is prioritized. The finer these interfaces are manufactured the better / the less post manufacturing processing is needed to ensure sufficiently mating surfaces, such as planar surfaces.

[0310] The second resolution manufactured e.g. with thicker layers would be more rough leading to more surface area. At least for middle and high frequency currents this may lead to conductance of more current without increasing the need for material / dimensions of the busbar. In fact, the middle segment may be manufactured intentionally with a corrugated surface to increase the current-carrying outer surface of the electrical busbar (current-carrying with medium and high frequencies) because of more efficient cooling due to the turbulence of, e.g., cooling air flow created due to the corrugated surface. It should be noted, that if the busbar includes an interior space, the inner surface of the busbars creating such interior space may also be corrugated for the same purpose. A corrugated surface has the effect, apart from offering a larger surface area, that it introduces turbulence in the flow of cooling fluid such as air. Increased speed of cooling fluid may lead to higher cooling effect.

[0311] As an example, the depth into the busbar which is used for conducting current at medium and high frequencies may in a specific embodiment be approximate 1 ,5mm. In this specific example, the busbar is made of copper with a resistivity of approximate 1.68pQ cm, a relative permeability of approximate 1 at a frequency of 2kHz. Thus, a busbar for this particular embodiment may be hollow having busbar thickness of 2 times 1 ,5mm. In practice such busbar may be manufactured with a thickness of 4-5mm leaving room for a cooling in the interior or simple reduction of busbar material and thereby weight.

[0312] Knowing that skin effect also appears at e.g. 50Hz, a reference to a medium frequency with respect to skin effect is a reference to frequency starting around 500Hz where the design of the busbar may account for the skin effect. The medium frequency range may be between 500Hz and 10kHz, above 10kHz may be referred to as high frequency where skin effect is a fact (the higher frequency, the closer to the surface the current will be conducted).

[0313] Further, it should be mentioned that the outer surface may also be corrugated or designed with fins for increasing heat dissipation from the electrical busbar.

[0314] The electrical busbar resulting from the method may be used as an electrical busbar of an electrical installation. The electrical installation may be an electric panel which may be part of a renewable energy facility such as a wind turbine, solar system, grid, substation, etc. The electrical installation or system in which the electrical busbar is used may be an electric vehicle, battery system, power to x facility, ship or other minor or larger electric systems. Further, an electrical busbar resulting from the method can be used inside an electric panel, i.e. in a cabinet / enclosure, or outside such panel, it can be used to connect separated panels, etc.

[0315] A variant of an electrical busbar according to the present invention is connected to a traditional cable or busbar. In such embodiment, a traditional busbar e.g. in the back of an electric panel or a traditional cable e.g. between two electric panels may be connected to an electrical busbar of the invention. In this way a traditional cable or busbar may be connected to a component via a busbar according to the invention. Thereby, an easy connection is facilitated due to the flexibility of the electrical busbar of the invention.

[0316] However, note that manufacturing the electrical busbar, and thus accomplishing the electrical and mechanical coupling between the first end segment and the second end segment, is typically performed prior to installing the electrical busbar in the electrical installation, and prior to installing the electrical installation in the renewable energy facility. Thus, according to typical embodiments of the invention, the electrical and mechanical coupling is performed prior to installation / integration of the electrical busbar. Nevertheless, methods according to the invention are not necessarily restricted to a particular sequence of steps. Further, various methods according to the invention may comprise additional steps, such as performing digital geometry optimization, additively manufacturing the electrical busbar, and conducting current.

[0317] Summing up, a designer is designing a digital representation of the busbar according to electrical, mechanical, structural, etc. requirements in e.g. a 3D CAD software such as Solidworks. Files (digital representation) from such 3D developing tool is exported to e.g. a 3D printer, where the busbar is printed according to the CAD files.

[0318] Fig. 3a - 3b illustrates a perspective view and a cross section of a partial busbar 1 according to an embodiment of the invention. A first end 2 and a portion of the middle segment 4 is illustrated. A first terminal 7 is located in connection with the first end 2, and the first terminal 7 comprises a couple of through holes 10 and a planar, uninsulated bottom surface for establishing a firm and good electrical connection to an electrical component or another conductor, such as a busbar. The middle segment 4 comprises a plurality of conductor branches 5 spaced apart by air gaps 6.

[0319] The busbar 1 comprises an electrically conducting component 20 and an electrically insulating component 30. In the example of figs. 3a-3b, the electrically insulating component 30 generally covers the electrically conducting component 20, except around the first terminal 7. A material of the electrically conducting component 20 may for example be selected from the list of copper, aluminum, silver, gold, tin, steel, or alloys or combinations thereof. Provided the electrically insulating component 30 is a continuous surface establishing an enclosure, the electrically conducting component 20 may also be selected from mercury, gallium, electrolyte or other nonsolid electrically conducting materials, or alloys or combinations thereof, preferably in combination with a solid metal for the first terminal 7. A material of the electrically insulating component 30 may for example be selected from the list of polymers, ceramics, thermoplastics, glass reinforced plastic, rubber, glass, wood, paper, oil, deionized water, or combinations thereof.

[0320] The electrically conducting component 20 is illustrated as a solid core of the busbar 1, but may in other embodiments comprise other geometries, shapes or configurations as described above, for example an airy geometry like bionic, latticelike or web-like to save material and weight, and / or comprise integrated cooling channels. In such embodiments, the electrically insulating component 30 may matchthe geometry and configuration of the electrically conducting component 20 more or less closely, for example comprising a slightly larger version of the same geometry to match the shape of the electrically conducting component, and / or comprising a smoother, larger version to accommodate the electrically conducting component without taking on its shape completely.

[0321] The busbar 1 of figs. 3a-3b comprises a number of auxiliary function regions 70, which are substantially overlapping in this particular embodiment. Due to the configuration with conductor branches 5, a heat transfer region 71, flexible region 73 and reduced material region 77 are achieved in addition to the main purpose of current conduction. Further, due to the electrically insulating component 30, an additional auxiliary function region 70 comprises an electrically insulated region 72. In fact, this electrically insulated region 72 extends over the entire insulated surface of busbar 1 (for simplicity not indicated in the drawing).

[0322] The embodiment of figs. 3a-3b may preferably be manufactured by two- material additive manufacturing, were both the electrically conducting component 20 and the electrically insulating component 30 are built simultaneously, or at least as one single process, e.g. with synchronous or alternating addition of material to the components. The arrow 66 illustrates a preferred additive manufacturing direction 66 for the example embodiment of figs. 3a-3b, but any other printing direction, depending on the additive manufacturing technology, may be usable, such as transversal, radial or arbitrary. Two-material additive manufacturing may be achieved by, for example, dual nozzle Fused Deposition Modelling FDM, where one nozzle delivers an electrically conducting material in form of a wire of, preferably, copper, aluminum or an alloy, or filament comprising a mixture of metal powder in a binder. Another nozzle delivers an electrically insulating material in form of a filament, e.g. made of thermoplastics such as polylactic acid PLA or acrylonitrile butadiene styrene ABS filament. Another possibility is cold spray additive manufacturing CSAM, again with at least two nozzles, one building the electrically conducting component 20, and the other simultaneously or synchronously, such as alternatingly, building the electrically insulating component 30, e.g. with polymer or ceramics. Yet another possibility isbinder jetting, where powders of electrically conducting material and electrically insulating material, respectively, may alternatingly be spread across the part being built, and after each spread, an inkjet print head is depositing binder appropriate for the particular powder at the locations where the particular powder should form the electrically conducting component 20 or electrically insulating component 30, respectively. Other dual-material additive manufacturing technologies may be applied in other embodiments.

[0323] In an alternative embodiment, the busbar 1 of figs. 3a-3b may be manufactured by providing the electrically conductive component 20, and afterwards applying the electrically insulating component 30 by surface treatment, e.g. coating or surface modification, or by a second additive manufacturing process. The electrically conducting component 20 may for example be manufactured by a powder bed fusion PBF technology such as selective laser melting SLM or selective laser sintering SLS, or any other suitable metal 3D-printing technology, using for example aluminum, copper or alloys, or any of the electrically conducting materials mentioned above. The electrically insulating component 30 may for example as mentioned be applied by surface treatment, e.g. painting or spraying, dip coating, etc., using any of the electrically insulating materials mentioned above. Alternatively, the electrically insulating component 30 may for example as mentioned be applied by additive manufacturing, e.g. by cold spraying CSAM or other suitable technologies, using any of the electrically insulating materials mentioned above. Thereby the auxiliary function region 70 may be provided by additive manufacturing.

[0324] Fig. 4 illustrates a non-limiting, simplified example of a dual-material additive manufacturing equipment 60, which in this example is in the process of manufacturing a busbar 1 with auxiliary function regions 70 as described above with reference to figs. 3a-3b. The additive manufacturing equipment illustrated may be a Fused Deposition Modelling FDM equipment, having a first nozzle 62 applying electrically conductive material for building the electrically conductive component 20, and a second nozzle 64 applying electrically insulating material for building the electrically insulating component 30. For simplicity, the illustration does not showmounting and movement systems for the nozzles and the table, material storing and conveying means, temperature control systems, controllers, power supplies, user interfaces, or other parts of the additive manufacturing equipment 60 known to the skilled person. The two nozzles 62, 64 may be actively applying material simultaneously or synchronously, such as altematingly, so that the busbar 1 is built step by step as a single polylithic unit. The same additive manufacturing equipment 60 may be utilized for manufacturing other embodiments with auxiliary function regions 70 described herein.

[0325] In various other embodiments, the additive manufacturing equipment 60 may be arranged for binder jetting, whereas the nozzles are replaced by binder inkjet-like heads, or for example for powder bed fusion PBF, where the nozzles are replaced with, e.g., laser emitters.

[0326] Fig. 5 illustrates a multi-phase electric busbar 1 according to an embodiment of the invention, in this example particularly 3 phases LI, L2, L3. The electric busbar 1 comprises three galvanically separate electrical conductor components 20 to carry the 3 separate phases LI, L2, L3, and correspondingly three of each first terminals 7 and second terminals 8. The multi -phase busbar 1 may preferably be utilized as a main busbar or connecting busbar, also referred to a high-power electrical local connecting busbar, in high-power electrical systems, e.g. power converters.

[0327] In the particular configuration of fig. 5, the terminals are manufactured with planar surfaces for simple and firm electrical connection to other conductors or electrical components, whereas the electrically conducting components 20 between the terminals are manufactured in an airy bionic, web-like or lattice-like geometry. Electrical busbar embodiments of such geometry are described above, with the various description and alternatives also applicable here, for example regarding conductor branches 5, airgaps 6, intersection points 9, ends and middle segments 2, 3, 4, etc., auxiliary functions like flexibility, cooling, heat dissipation, etc., various manufacturing methods, etc. Other geometries of the electrically conducting component 20 as described herein are also applicably to the busbar 1 of fig. 5. Further, in the particular configuration of fig. 5, electrically insulating components 30 areprovided at various select portions of the busbar 1. For example, electrically insulating components 30 may be formed between separate phase conductors LI, L2, L3 to allow for reduced safety clearance which in turn may reduce the footprint of, for example a main busbar replaced by the multi-phase busbar 1. For example, electrically insulating components 30 may be formed at select surface portions of the phase conductors LI, L2, L3 where operators or service technicians may come close to the busbar in connection with their work. For example, electrically insulating components 30 may be formed as support structures for maintaining the relative position of the separate phase conductors LI, L2, L3 to each other. For example, electrically insulating components 30 may be formed as mounting points for mounting the multi -phase busbar 1 to a cabinet or panel, for example for each 25 to 35 cm, without requiring further insulating material to be provided for the mounting. Alternatively, insulated mounting points may be formed as hooks, clamps, latches, etc., for easy mounting without bolts. For example, electrically insulating components may be formed as support structures to support other electrical components or conductors, for example insulated support structures provided adjacent to the terminals as in the illustrated example.

[0328] The multi -phase busbar 1, in addition to its main purpose of current conduction and distribution, comprises a number of auxiliary function regions 70. For example, electrically insulated regions 72 are provided in multiple regions in the example. For example, heat transfer regions 71 and reduced material regions 77 are provided in a similar way as described above with reference to figs, lb and 1c. For example, mechanical support regions 74 are provided, in this example to support the three phase conductors to each other, and to provide additional support to connected electrical component adjacent to second terminals 8. For example, mounting regions 75 are provided for mounting the multiphase busbar 1 at regular intervals along a cabinet frame or the like. Advantageously, all the auxiliary function regions 70 described may be manufactured by additive manufacturing, either together with the multiphase busbar 1 as one polylithic part, or by adding them to a multiphase busbar 1 by additive manufacturing, e.g. by cold spray CSAM or other suitable AM technology.

[0329] The busbar 1 of this embodiment may advantageously be manufactured completely by additive manufacturing to form a polylithic unit, where the phase conductors LI, L2, L3, although galvanically separate, are interweaved in a way that may not be easily achieved, if possible at all, by combining individually manufactured conductors, and further are intrinsically combined by patches of electrically insulating component 30. The alternative manufacturing methods described in relation to other embodiments herein are also applicable for this embodiment, such as manufacturing, e.g., the electrically conducting components 20 by additive manufacturing, and the forming the electrically insulating components 30 by a separate additive manufacturing step, or by surface treatment methods, such as coating or surface modification.

[0330] A multi -phase busbar 1 may be highly advantageous for multiphase electrical systems as it may replace conventional, separate busbars consisting of heavy solid copper bars or rails, which require large safety clearances, several different connecting busbars for the difference phases, manual insulation application, additional insulation for mounting, separate mounting means, etc. The present invention allows for providing a single unit which offers all the relevant functions for a high-power multiphase busbar. Further advantages which are not conventionally achieved include that all phase conductors may have the same distance between the terminals, to avoid discrepancies in resistive loss, heat distribution, etc. The multi-phase busbar 1 may in various embodiments comprise any number of galvanically separate electrically conducting components 20, such as one, two, three, four, five, six, or any other number of busbars. While the multi-phase busbar 1 is shown here with a twisted wire-like configuration, the phase conductors may in various embodiments comprise any interconductor geometry, including parallel phase conductors, etc.

[0331] Figs. 6a-6b illustrate two perspective views of a busbar 1 with multiple auxiliary function regions 70 according to an embodiment of the invention. A relatively solid electrically conducting busbar region extends between first terminal 7 and second terminal 8 with the main purpose of conducting current between the terminals.

[0332] Along the solid busbar part, heat transfer regions 71 have been added by additive manufacturing as auxiliary function regions 70. In this example they are designed with a web-like or bionic geometry, and protrude significantly from the solid busbar part. Thereby they become effective in transferring heat from the solid part of the busbar to the ambient air, which may further preferably be actively blown through the heat transfer regions 71. This may have the effect that the cross section of the solid part can be reduced in comparison to conventional solid busbars without heat transfer region 71.

[0333] Near the first terminal 7, in this example, a flow guiding region 76 is provided as an auxiliary function region 70 by additive manufacturing to the busbar 1. In this example it consists of printed protrusions which forms numerous small dimples in the busbar surface. The dimples cause air flowing over the surface to become more turbulent, thereby improving heat transfer from the busbar.

[0334] Also near the first terminal 7 is illustrated a mounting region 75 as another auxiliary function region 70 provided by additive manufacturing on the busbar 1, and facilitates mounting of the busbar 1 to a frame or other support structure without requiring additional clamps, separate flanges, etc.

[0335] Fig. 7 illustrates an embodiment of an electrical busbar 1 with auxiliary function regions 70 according to the invention. The busbar 1 is based on the busbar 1 described above with reference to figs, lb, and all the above description also applied to this embodiment, including the auxiliary function regions 70 comprising at least a mounting region 75, a heat transfer region 71 and a reduced material region 77, as described above.

[0336] Further, the embodiment of fig. 7 comprises further auxiliary function regions 70 provided by additive manufacturing on the busbar 1. The busbar 1 comprises an electrically conducting component 20 which may preferably be manufactured by additive manufacturing as described above, as well as an electrically insulating component 30 covering a part of the surface of the electrically conducting component 20. The electrically insulating component 30 forms an auxiliary function region 70being an electrically insulated region 72. The partial insulation of the conducting part facilitates reduced safety clearance at those portions, which may be beneficial when the electrical busbar 1 is to pass through narrow spaces as described above, or when it is beneficial to allow the busbar to pass by another conductor at low or no distance. This embodiment is particularly advantageous for high-power electrical systems, e.g. as a high-power electrical local connection busbar, with high voltages requiring larger safety clearance when relying on air insulation.

[0337] The electrically insulating component 30 is illustrated with a complex shape providing a non-flat outer surface, as well as several air channels between the electrically conducting component 20 and the electrically insulating component 30. For illustration purposes, the complex shape and air channels are shown to a much larger scale than preferred. The non-flat outer surface may facilitate turbulence of air flow for cooling, and the air channels between the conducting and insulating components may facilitate heat dissipation even where the busbar is covered by insulation. It is also noted that the web-like design of this embodiment allows cooling air to pass through inside the conductor outer perimeter, and thereby also unrestricted flow through the insulated portion. Thereby the embodiment also comprises a flow guiding region 76 as another auxiliary function region 70, provided by additive manufacturing. In various embodiments, the electrically insulating component 30 may be a simpler geometry, such as a flat-surfaced sleeve, or even more complex geometries, possibly comprising air guides, mounting points, etc. In various embodiments, the electrically insulating component 30 may form several connected or separate transversal bands on the electrical busbar 1.

[0338] In the embodiment of fig. 7 the electrically insulating component 30 may preferably be manufactured and applied to the electrically conducting component 20 in one process by using additive manufacturing, e.g. simultaneously or synchronously with the manufacturing of the electrically conducting component 20, or by a subsequent, separate additive manufacturing step.

[0339] Fig. 8 illustrates an embodiment of a separate additive manufacturing of auxiliary function regions 70. The present example is based on the embodiment of fig.7, but the other auxiliary function regions 70 described elsewhere herein may be manufactured accordingly. A cold spray additive manufacturing CSAM equipment 60 is provided. In various embodiments, the part 1 and / or the nozzle 62 may be fixedly mounted, or may preferably, as illustrated, be moveably mounted, preferably by means of multi -joint arms, allowing a high degree of freedom of moving and rotating both part 1 and nozzle 62, and thereby allowing for arbitrary additive manufacturing direction, whereby this direction is not indicated in the drawing. In some embodiments the part 1 or nozzle 62 may be mounted in a turning lathe to only allow rotatably motion, thereby causing the additive manufacturing direction to be radial to the rotation axis, and allowing the applied layers to be curved.

[0340] In an embodiment, the cold spray additive manufacturing CSAM equipment 60 may further include two nozzles with different spray material in order to manufacture, e.g., electrically conducting component 20 and electrically insulating component 30 simultaneously or synchronously.

[0341] Fig. 9a illustrates a projection of an electrical system 40 here being a high- power converter 50 according to an embodiment of the invention. This converter 50 is enclosed in an electrical cabinet 42 comprising electrical components 48 such as circuit breakers of which the back side is illustrated. This circuit breakers are also connected to a power infeed of converter 50. The power supply to the converter 50 may be the grid or a local power generator such as a wind turbine or a solar panel.

[0342] The circuit breakers 48 are in this embodiment connected to other electrical component 48 such as reactors or inductors 48 in the bottom of the cabinet 42 with cables. Further, cables connects the reactors 48 to power modules 52.

[0343] The output side of the power modules 52 are in this embodiment connected to a laminated busbar plates behind the power modules 52, which via busbars le are connected to main output busbars If. This main output busbars is connected to outfeed of the power converter 50, to which, e.g., a load or grid may be connected.

[0344] Fig. 9b illustrate a power module 52 in more detail. An output side of the power module 52 in in this embodiment connected to a laminated busbar plate behindthe power modules 52, which via busbars le are connected to main output busbars If (fig. 9a). This main output busbars is connected to outfeed of the power converter 50, to which, e.g., a load or grid may be connected.

[0345] Transition busbars la-ld (fig. 9b) are provided to receive cable connections from the reactors / inductors. The transition busbars la-ld are highly specialized to achieve various auxiliary function regions 70, to fit the available space and clearance requirements, and to achieve a sufficient heat transfer and cooling in the cabinet 42. Due to the specialization, convention busbar manufacturing is disadvantageous, and the busbars la-ld may advantageously be printed by additive manufacturing including auxiliary function regions 70.

[0346] The busbars la-lf may advantageously comprise auxiliary function regions 70 manufactured by additive manufacturing as described herein. Highly advantageous is heat transfer regions 71, for example achieved by web-like or bionic or other non- uniform geometries of the busbars. Also advantageous may be electrically insulated regions 72, flexible regions 73, mechanical support regions 74, mounting regions 75, flow guiding regions 76, reduced material regions 77, etc.

[0347] A busbar la-lf of the present invention may be manufactured at least partly by an additive manufacturing process and thus the geometry may be tailor made to the footprint, available space, cooling capacity, current capacity, etc. that is limiting or required from the transition busbar. A few examples of geometry and design of suitable busbars are illustrated above in figures la-lc, 3a-3b, 5, 6a-6b and 7.

[0348] It should be mentioned that studs may be provided on the surface of busbars 1 comprised by the cabinet 42 of the present invention. Studs are advantageous in that if located e.g. every 5mm then they will create a turbulence at the surface which increases the cooling efficiency of the busbars. The studs may be attached during manufacturing such as during additive manufacturing or post manufacturing e.g. via cold spray.

[0349] The power modules 52 comprise a plurality of semiconductor switches such as IGBTs. These power modules 52 are controlled by a converter controller so as toperform the function of e.g. an inverter or rectifier. On that node, the illustrated power converter 50 is an AC to DC converter where three phases e.g., from the utility grid enter the converter 52 and is converted to a DC supply e.g., for an electrolyser. It should be noted that the converter 52 may also be a DC to AC, DC to DC, or AC-AC converter.

[0350] The converter 52 may comprise a filter e.g. comprising capacitors, damping resistors, and trap chokes. This filter may be included in the converter to ensure that the output voltage from the converter is smoothed e.g. to comply with grid codes.

[0351] The converter 50 may comprise a cooling system 43. The cooling system may include cooling loops via which the components such as the reactor, filter and power modules are cooled. The cooling system may circulate a cooling fluid, such as a liquid or gaseous coolant. Such liquid coolant may e.g. be selected as a type of oil which may be non-electrical conductive and thereby work as both cooling fluid and isolator, water, deionized water, Glycol, liquid, metal such as Gallium, mercury, etc. The cooling system may circulate the cooling fluid in the cooling loop with a flow speed in the range of 4L / min to lOL / min per power module. Therefore, the cooling system should be able to provide a flow of cooling fluid in the range of 48L / min to 120L / min in electrical systems having parallel power modules on each of three phases (12 power modules x 4-10L7min). The temperature of the cooling fluid is preferably below 55C in that it is desired to maintain a temperature below 55C in the high-power electric system.

[0352] In addition to traditional converter cooling systems, the converter 50 may furthermore be cooled via the busbars 1. The busbars may be provided with heat transfer regions 71 in the form of internal channels that may be part of the cooling loops. In this way the cooling fluid may be directed closer to the electrical components 48, 52, and more important it may cool components that with known technology is not possible to include in a cooling loop.

[0353] This is possible in that e.g. the transition busbar carrying a high current to a power module thereby is generating a temperature increase can be cooled from a fluid conducted in an internal channel which is included in a cooling loop.

[0354] The cabinet 42 comprising the converter 50 may in addition to the cooling from closed internal channels described above also be cooled by an air flow from one or more fans. Such air flow may be provided between an air inlet and an air outlet in the cabinet 42. This flow of air may also transport heat from inside of the cabinet or more particular from the surface of the busbars such as the transition busbars and out of the cabinet.

[0355] This traditional way of cooling a cabinet has a rather limited effect on cooling the components such as the conductors of the cabinet. However, in the present invention where e.g. transition busbars are manufactured in an airy design as a heat transfer region 71, such air flow has an improved cooling effect. This is because a transition busbar or a conductor branch thereof may along most of its length, in some embodiments along all of its length, be cooled from all angles i.e. a 360° cooling of the conductor branches is possible.

[0356] More specific, a known massive conductor such as a main busbar with a length of e.g. 3-5m may conduct 1-2A per mm2. If the same busbar was made in an airy design and e.g. with an internal cooling, then due to the improved cooling the same 1-2 A per mm2 may be conducted with the same efficiency despite the removal of material. Typical conductor materials such as aluminium and copper have temperature coefficients at approximately 0.4% / deg C. If such conductor is efficiently cooled so that the temperature is e.g. 25 deg C lower compared to a conventional conductor, the resistance is reduced by approximately 10%. Hence approximately 10% of the material can be removed without compromising the losses. Furthermore, in AC conductors the current is not evenly distributed across the conductor volume. Typically, the current density is reduced towards the center of the conductor. Taking such considerations into account can allow for further removal of material without compromising the efficiency of the conductor.

[0357] Further, a conductor such as a transition busbar having internal cooling channel and an airy design having a length of e.g. l-2m may conduct 10-15 A per mm2 and in an extreme case with massive cooling an a distance no longer than e.g. 10cm, such conductor may conduct 50A per mm2. Care should be taken when reducing the cross-sectional area in that more heat is generated which need to be removed if the same current should be conducted by a smaller cross-sectional area. The loss increases quadratic with the increase of current. Therefore, the efficiency of the conductor is also reduced when the material hereof is reduced.

[0358] In addition to the above-mentioned features, the busbars 1 may include one or more of several additional features which makes it advantageous over prior art busbars. One such feature is a non-uniform geometry of busbars 1. With non-uniform and tailormade busbars 1 it is possible to make a more compact design of the electrical system 40, e.g. power converter 50, in that the busbar (including main and transition busbars) may be shaped according to available space and location of components in the cabinet. This may include branching off in two or more conductor branches, change to an airy design if additional cooling for some reason is required, narrow the cross- sectional area of the conductor 1 and thereby establish a heater if required for some reason of if the conductor 1 has to go through a current sensor, etc. As an example of the advantage of being able to create heat could be mentioned that during start up, if a certain part of a cabinet is prone to condensation, that part of the cabinet may be heated up by conducting current through a narrow cross-sectional area of the conductor in such area. Another example is a circuit breaker which may require a certain heat dissipation from a connected conductor. Such requirement to heat dissipation may be complied with, with less material by a conductor with varying / airy geometry compared to known massive conductors. In fact, it may be possible to rate up the circuit breaker due to the optimized heat dissipation from the conductor connected to the circuit breaker.

[0359] Another such feature is electrical busbars such as those denoted la-ld of fig. 9b. These busbars may, by additive manufacturing, be monolithically formed as one single busbar including all the benefits from the individual busbars. Hence, onemultifunctional busbar may be manufactured having varied cross-sectional area according to where cables are connected (la), conducting of current (lb), cooling (la, 1c), facilitates mount of several such as five ferrite cores (1c) and flexibility (Id). By manufacturing one multifunctional busbar with two or more of these characteristics’ material may be saved, better cooling may be obtained, more flexible busbar may be provided leading to easier mounting, the number of connections of busbars is reduced and a more compact layout of the converter 1 may be achieved Such multifunctional busbar may have a wedge formed part for connecting cables, a twisted design allowing the conductor to form a solenoid of five windings around a core and a branch off for connecting to the power modules.

[0360] Further, mounting such multifunctional busbar is faster than connecting four individual busbars and less manual mounting eliminate sources of errors and when connecting two parts requires space for tool and larger distances to other components in general due to concerns of tolerances. Further, by using busbars with airy design and / or internal cooling channels the design can be more compact because of the optimized cooling and thus busbars 1 may be located closer to other components.

[0361] Fig. 10 illustrates a busbar 1 of the invention with an internal cooling fluid channel 12 connected to a cooling system 43 via tubing.

[0362] It should be mentioned that the cooling loop may include more than one channel 12. Thus, channels 12 of two busbars 1 may be connected with a pipe or hose of a non-conductive material. The outlet of one busbar may be fluidly connected to the inlet of another busbar and in this way establish an extended loop which includes a plurality of channel 12 of one or more busbars 1. If the hose is of a non-conductive material in principle, the busbars may not need to be of the same phase. In this case it may be preferred to have a fluid circulated in the hoses which is non-conductive.

[0363] The internal cooling channel 12 may e.g. be formed as or with a channel extension, so that, as the busbar 1 is manufactured, the inlet and / or outlet of the channel 12 may also be manufactured by additive manufacturing. In this way the fluid connections to the channel 12 by the loop is easy to establish simply by a providing aloop pipe over the extension and e.g. in addition provide a hose clamp around the pipe. Such extension may be designed in any desired relevant way and thus be relatively long for it to end at a desired location. Such desired location may be desired e.g. with respect to service and maintenance, mounting, etc.

[0364] The busbar 1 thereby comprises an auxiliary function region 70 being a heat transfer region 71 formed by the internal cooling channel 12 provided by additive manufacturing of the busbar 1.

[0365] The surface of the busbar 1 may be airy or flat and it may comprise nonillustrated air guides for guide a flow of air in a predetermined direction, thereby comprising also a flow guiding region 76 for an additional auxiliary function region. Further, the busbar 1 may include a heat sink for transporting heat from the surface of the busbar to the surroundings. Both the air guide and the heat sink may be integrated i.e. manufactured as an outgrowth from the surface of the busbar. Hence, during manufacturing of the busbar, the air guide and / or the heat sink may be monolithic formed as one with the busbar. Alternatively, the heat sink and / or the air guide may be external mounted to the busbar. Such mounting may be via incorporated mounting points of the busbar. Such mounting points may be monolithic formed as one with the busbar during manufacturing of the busbar.

[0366] The embodiment of a busbar 1 with auxiliary function regions 70 illustrated in fig. 11 could be said to be an advantageous combination of several different busbar designs. The busbar 1 illustrated on fig. 11 is of a twisted type. It has three central body segments. A first is separating one larger twisted part into six twisted parts individually having a smaller diameter than the larger twisted part of the electrical busbar. The central body segments allow insertion of a ferromagnetic core for filtering. The six twisted conductor branches each terminate in a first end 2. These six first end segments are connected to an additional electric component via a nut and bolt connection. The second end 3 is also connected to an additional electric component via a nut and bolt connection.

[0367] All of the central body segments are built of conductor branches 5 having airgaps 6 therebetween.

[0368] The embodiment illustrated in fig. 11 is one example of a busbar 1 having different dimensions i.e. a thick part connected to the second end 3 and to a thinner inductor part which again is connected to a thick part.

[0369] Reducing the diameter at certain portions may come with the disadvantage that the thinner part becomes hotter than the thicker part in that the same current is running through the two parts. However, the busbar may be designed so that it is just before the coiled part starts, the diameter is reduced and just after the coiled part ends, the diameter is reshaped back to the thicker diameter again. In such design heat may be dissipated from the coiled / inductor part (thinner part) towards and into the thicker part. Further, the coiled part is small so this part having higher resistance than the remaining part of the busbar is which will reduce the heat generations. Further, the design illustrated where it may be possible to circulate air through the twisted conductor branches, may facilitate better cooling.

[0370] Thereby, as described, the busbar 1 provides several auxiliary function regions 70, most notably a high degree of flexibility at several flexible regions 73.

[0371] Fig. 12 is another embodiment of a busbar 1 with auxiliary function region 70 provided by additive manufacturing. The auxiliary function regions 70 at least comprise heat transfer region 71, flexible region 73, flow guiding region 76 as air is guided through the accordion parts, and a reduced material region 77.List of reference signs:1 Electrical busbar2 First end3 Second end4 Middle segment5 Conductor branch5’ Conductor branch element6 Air gap7 First terminal8 Second terminal9 Intersection point10 Terminal hole11 Integrated heat sink12 Internal cooling fluid channel13 Coolant flow guide14 Air guide20 Electrically conducting component30 Electrically insulating component40 Electrical system42 Electrical cabinet43 Cooling system44 Main busbar46 Transition busbar, connecting busbar, shunt48 Electrical components50 Power converter52 Power module60 Additive manufacturing equipment62 Additive manufacturing first nozzle64 Additive manufacturing second nozzle66 Additive manufacturing direction70 Auxiliary function region71 Heat transfer region72 Electrically insulated region73 Flexible region74 Mechanical support region75 Mounting region76 Flow guiding region77 Reduced material regionLI, L2, L3 Separate phase conductors

Claims

Claims1. An electrical busbar (1) comprising at least one first terminal (7) and at least one second terminal (8) and being configured to support conductance of an electric current between said at least one first terminal (7) and said at least one second terminal (8), characterized in that said electrical busbar (1) is at least partly manufactured by additive manufacturing to comprise at least one auxiliary function region (70).

2. The electrical busbar (1) of claim 1, wherein said at least one auxiliary function region (70) comprises one or more from the list of a heat transfer region (71), an electrically insulated region (72), a flexible region (73), a mechanical support region (74), a mounting region (75), a flow guiding region (76), a reduced material region (77), or combinations thereof.

3. The electrical busbar (1) of claim 1 or 2, wherein said at least one auxiliary function region (70) comprises a heat transfer region (71) comprising at least one internal cooling fluid channel (12) and / or wherein said heat transfer region (71) comprises at least one integrated heat sink (11).

4. The electrical busbar (1) of the claim 3, wherein said integrated heat sink (11) forms part of said electrical busbar (1) at said heat transfer region (71), and wherein said integrated heat sink (11) is at least partly manufactured with an air penetrating geometry, for example by comprising a plurality of conductor branches (5) having airgaps (6) between them.

5. The electrical busbar (1) of any of the claims 3-4, wherein said middle segment (4) of said busbar (1) with said integrated heat sink (11) is manufactured as one monolithic geometry by additive manufacturing, wherein said monolithic geometry comprises one or more protrusions (11b) or one or more recesses (11c), such as one or more outgrowing cooling fins.

6. The electrical busbar (1) of any of the claims 3-5, wherein said heat transfer region (71) is thermally connected with a heat generating electrical component (48) wherein a physical location of said thermal connection at said electrical component (48) isdifferent from a physical location of an electrical connection from said electrical component (48) to an electrical busbar, such as said busbar (1).

7. The electrical busbar (1) of any of the claims 3-6, wherein said heat transfer region (71) with integrated heat sink (11) is located in an electrical cabinet (42) at a location of a hot spot.

8. The electrical busbar (1) of any of the claims 3-7, wherein said heat transfer region (71) comprises at least one internal cooling fluid channel (12), wherein said at least one internal cooling fluid channel (12) has a geometry selected from the list comprising: gyroid-like, web-like, circular, oval, triangular, rectangular, square, pentagon and multi sided.

9. The electrical busbar (1) of any of the claims 3-8, wherein said at least one internal channel (12) is monolithically formed with a channel extension.

10. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises an electrically insulated region (72), wherein said busbar (1) comprises an electrically conducting component (20) and said electrically insulated region (72) is formed by an electrically insulating component (30),11. The electrical busbar (1) of claim 10, wherein said electrically insulating component (30) is manufactured together with said electrically conducting component (20) by multi-material additive manufacturing.

12. The electrical busbar (1) of any of the claims 10-11, wherein the electrically insulating component (30) forms one or more transversal bands on the electrically conducting component (20).

13. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises a flexible region (73).

14. The electrical busbar (1) of claim 13, wherein said flexible region (73) comprises a middle segment (4) of said busbar (1) formed by a plurality of conductor branchelements (5’), such as one or more conductor branches (5) wherein said plurality of conductor branch elements (5’) are spaced apart by airgaps (6) establishing a line-of- sight through said electrical busbar.

15. The electrical busbar (1) of any of the claims 13-14, wherein said airgap (6) is in the range of 0.01cm to 40cm, for example below 20cm, 15cm or 10cm, such as below 1cm, such as below 0.5cm, for example below 0.25cm.

16. The electrical busbar (1) of any of the claims 13-15, wherein said conductor branches (5) are configured so that said airgaps (6) change geometry as consequence of a force applied to said busbar (1).

17. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises a mechanical support region (74), wherein said mechanical support region (74) comprises additional busbar material or an increased density of busbar material, compared to an average of the busbar.

18. The electrical busbar (1) of claim 17, wherein said mechanical support region (74) comprises protrusions from said busbar (1).

19. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises a mounting region (75).

20. The electrical busbar (1) of claim 19, wherein said mounting region (75) comprises additional busbar material or an increased density of busbar material, compared to an average of the busbar.

21. The electrical busbar (1) of any of the claims 19-20, wherein said mounting region (75) comprises protrusions from said busbar (1).

22. The electrical busbar (1) of any of the claims 19-21, wherein said mounting region (75) comprises one or more support items selected from the list of: through hole for bolts or screws, protruding rod, threaded protruding rod, flange, hook, clamp, clip, groove, threaded bolt hole, a polygonal countersunk cavity to receive a bolt head, or combinations thereof.

23. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises a flow guiding region (76), wherein said flow guiding region comprises at least one air guide (14)as an integrated part of said electrical busbar (1) at the flow guiding region (76).

24. The electrical busbar (1) of claim 23, wherein said at least one air guide (14) is integrated as part of said electrical busbar (1) as a protrusion at the surface at said flow guiding region (76).

25. The electrical busbar (1) of any of the claims 23-24, wherein a plurality of individual air guides (14) is outgrowing from the surface of said busbar (1) at the flow guiding region (76) in different directions.

26. The electrical busbar (1) of any of the claims 23-25, wherein said at least one air guide (14) is integrated as part of said electrical busbar (1) as a recess at the flow guiding region (76).

27. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises a reduced material region (77).

28. The electrical busbar (1) of claim 27, wherein the busbar (1) at the reduced material region (77) comprises a plurality of conductor branch elements (5’), wherein the busbar (1) at the reduced material region (77) is manufactured in a geometry from the list comprising: bionic, web, sponge, honeycomb, wavelike, gyroid-like and branchlike.

29. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises a heat transfer region (71) and an electrically insulated region (72).

30. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises a heat transfer region (71) and a flexible region (73).

31. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises a heat transfer region (71), a flexible region (73) and a mounting region (75).

32. The electrical busbar (1) of any of the preceding claims, wherein said at least one auxiliary function region (70) comprises at least two partly or fully overlapping auxiliary function regions (70).

33. The electrical busbar (1) of any of the preceding claims, wherein one or more of the at least one auxiliary function region (70), such as a heat transfer region (71) or a flexible region (73), extends to substantially the entire electrical busbar (1), such as at least 75%, e.g. more than 90% of the busbar surface.

34. The electrical busbar (1) of any of the preceding claims, wherein one or more of the at least one auxiliary function region (70) is distributed into a plurality of sub regions, e.g. a plurality of electrically insulated regions (72), mechanical support regions (74) or mounting regions (75).

35. The electrical busbar (1) of any of the preceding claims, wherein the electrical busbar (1) is manufactured by additive manufacturing as a single workpiece.

36. The electrical busbar (1) of any of the preceding claims, wherein the additive manufacturing comprises multi-material additive manufacturing.

37. The electrical busbar (1) of any of the preceding claims, wherein the electrical busbar (1) comprises a main busbar (44) to be mounted along a top, back, side or bottom of an electrical cabinet (42), wherein the electrical busbar (1) comprises a transition busbar, a connecting busbar or a shunt (46), configured to connect electrical components (48) or other busbars (46) with main busbars (44) or cables.

38. The electrical busbar (1) of any of the preceding claims, wherein the electrical busbar (1) comprises two or more, such as three, separate phase conductors (LI, L2, L3), each having first and second terminals (7, 8) and supporting individual current conductance between the respective first and second terminals (7, 8), preferablywherein each separate phase conductor comprises at least one of said at least one auxiliary function region (70).

39. The electrical busbar (1) of any of the preceding claims, wherein the electrical busbar (1) is a high-power electrical local connecting busbar (1).

40. Electrical system (40) comprising one or more electrical components (48) connected to one or more electrical conductors (44, 46), at least one of the electrical conductors being an electrical busbar (1) at least partly manufactured by additive manufacturing to comprise at least one auxiliary function region (70).

41. The electrical system (40) of claim 40, wherein the electrical system (40) is a high- power electrical system (40) and the electrical busbar (1) is a high-power electrical local connecting busbar (1).

42. The electrical system (40) of claim 40 or 41, wherein the electrical busbar (1) is the electrical busbar (1) according to any of the claims 1 - 39.

43. The electrical system (40) of any of the claims 40-42, wherein the electrical system (40) is comprised in an electrical cabinet (42) or panel.

44. The electrical system (40) of any of the claims 40-43, wherein the electrical system (40) comprises a power converter (50), such as an AC -DC converter, a DC-AC inverter, an AC -DC-AC converter, a frequency control driver, a battery charger, etc.

45. The electrical system (40) of any of the claims 40-44, wherein at least one of the one or more electrical components (48) is a power module (52), preferably a switch mode power module, such as an insulated-gate bipolar transistor IGBT power module or a metal-oxide-semiconductor field-effect transistor MOSFET power module, etc.

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