Conductor for an electric machine
By designing a region layout with higher and lower conductivity in the motor conductor, the energy loss problem caused by eddy current and skin effects during high-frequency operation is solved, and the motor performance is improved, and the conductor is manufactured simple and inexpensive.
Patent Information
- Application Number
- CN202280096539.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2022-05-27
- Publication Date
- 2025-02-25
AI Technical Summary
The existing motor conductors are highly energy loss due to eddy current and skin effects when operating at high frequency, which affects motor performance, and the Leeds line is expensive to manufacture and difficult to assemble.
A conductor is designed that includes two regions with higher conductivity and one region with lower conductivity. The areas with lower conductivity are composed of conductive materials with multiple breakpoints, and the areas with lower conductivity are arranged between areas with higher conductivity to reduce energy loss from eddy currents and skin effects.
Through this conductor design, energy loss caused by eddy current and skin effects can be effectively reduced, without suppressing the flow of current in the length of the conductor, and improving motor performance. In addition, the manufacturing of the conductor is simple and inexpensive.
Smart Images
Figure CN119522527A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a motor, and in particular to a conductor used in the motor. Background Art
[0002] An electric motor includes at least one current-carrying component in the form of an electrically conductive conductor or wire. Energy losses incurred when passing current through a conductor can be detrimental to the performance of the motor. These losses can be due to: resistance to direct current ("DC") electron flow in the wire; losses due to skin effect; and losses due to eddy currents.
[0003] The losses typically cause the temperature in the motor to rise. Lower temperatures, typically achieved through active cooling, often limit the maximum performance of the motor, so reducing the energy losses from the conductors can significantly improve performance.
[0004] For inverter driven motors operating at a high fundamental frequency, the resistive (DC) component of the losses is relatively small. The high fundamental frequency may be at least 1 kHz or may be greater than 10 kHz. For example, the total losses in a copper wire may be 2.5 times higher when subjected to alternating current ("AC") than when the same direct current is passed through the same wire. A large portion or most of these losses may be the result of noise generated by the inverter switching frequency, which may be at least 10 times the fundamental frequency of the motor. The inverter switching frequency of an inverter driven motor may be at least 10 kHz, and optionally may be at least 20 kHz.
[0005] In inverter-driven machines running at more modest frequencies, the skin effect may be relatively low and a greater proportion of the losses may be due to eddy currents, where these currents flow perpendicular to the intended direction of travel. Moderate frequencies may be less than or equal to 1 kHz.
[0006] A common solution to eddy currents and skin effect is to use Litz wire. Litz wire includes multiple conductors (i.e., wires), each of which is independently insulated from the others and braided or twisted in a specific arrangement. It is known that each conductor of Litz wire is uniform in composition and conductivity. It is known that each conductor of Litz wire includes a homogeneous conductive material.
[0007] The insulation between the wires may include enamel and prevent the wires from acting like bar wire and experiencing skin effect and eddy current effects. Twisting or braiding the wires makes the electromotive force ("EMF") applied to each wire uniform, which avoids circulating currents within the wires and balances the current flowing through all the wires, which also reduces energy losses. The combination of insulation between the wires and the braiding gives a conductor with reduced energy losses.
[0008] However, Litz wire can be expensive to manufacture, difficult to assemble into a stator, and in an electric machine, the slot fill factor can be poor. Heat dissipation from the Litz wire can also be limited due to the low thermal conductivity of the wire insulation (e.g., enamel) within the Litz wire bundle.
[0009] Therefore, there is a need for improved conductors for electric machines. Summary of the invention
[0010] A first aspect of the present invention provides a conductor for an electric machine. Wherein, the conductor comprises: two areas of higher conductivity; and a region of lower conductivity, the region of lower conductivity comprising a conductive material having a plurality of discontinuities in the conductive material such that the region of lower conductivity has a lower conductivity than the region of higher conductivity; The region with lower electrical conductivity is arranged between the two regions with higher electrical conductivity so as to at least partially separate the two regions with higher electrical conductivity along the length direction of the conductor.
[0011] This aspect has the advantage of reducing energy losses due to eddy currents and skin effect without inhibiting the flow of current in the length direction of the conductor. Specifically, the area of higher conductivity allows the current to flow unrestricted along the length direction of the conductor, while the area of lower conductivity restricts the current to flow in the lateral direction of the conductor. This directional conductivity reduces eddy currents and associated energy losses. This aspect also provides a conductor that is simple and inexpensive to manufacture. This aspect also provides a conductor with improved thermal conductivity. For example, compared to the insulation in Litz wire, the area of lower conductivity has improved thermal conductivity.
[0012] The conductor may be additively manufactured. The conductor may have a microstructure indicating that it has been manufactured using additive manufacturing. Additive manufacturing may involve depositing particles and sintering or otherwise fusing the deposited particles together, for example by using an energy beam. This has the advantage of providing a conductor that is simple and inexpensive to manufacture.
[0013] The chemical composition of the conductive material of the regions of lower conductivity may be substantially the same as the material of the regions of higher conductivity. This has the advantage of providing a conductor that is simple and inexpensive to manufacture. One or more of the regions of lower conductivity and / or the regions of higher conductivity may comprise copper. This has the advantage of providing a conductor that is not thermally limited.
[0014] The region of lower conductivity may include a plurality of particles. The discontinuities may be voids or pores between particles. The discontinuities may be cracks or microcracks at the points where the particles are closest or in contact (i.e., at the intersections between particles), and / or the discontinuities may be voids between particles. The region of higher conductivity may include a plurality of sintered particles. The region of lower conductivity may be more porous than the region of higher conductivity. The discontinuities may include voids, gaps, cracks, or microcracks.
[0015] Regions of higher conductivity may be connected to each other through regions of lower conductivity. Regions of higher conductivity may be mechanically connected to each other through regions of lower conductivity. The density of regions of higher conductivity may be higher than the density of regions of lower conductivity.
[0016] Along the length of the conductor there may be at least one longitudinal section or zone without any areas of lower conductivity. This has the advantage of providing a conductor which reduces energy losses in areas where energy losses are typically detrimental while having high conductivity in areas where energy losses are less likely or less detrimental to the overall performance of the motor.
[0017] The region of lower conductivity may extend in the length direction of the conductor. The region of lower conductivity may extend substantially parallel to the outer surface of the conductor. The region of lower conductivity may be substantially uniform along its length. This has the advantage of providing a particularly efficient arrangement in which the conductive path for the flow of DC current is provided between or around the region(s) of lower conductivity.
[0018] One or more bridge portions may be provided across regions of lower conductivity to mechanically and / or electrically connect these regions of higher conductivity to each other. This has the advantage of providing a conductor with improved structural or mechanical integrity.
[0019] The conductor may include multiple regions of lower conductivity. Optionally, the conductor includes at least three regions of lower conductivity. Multiple regions of lower conductivity may extend parallel to each other along the length of the conductor. This provides a conductor with reduced energy losses. The conductor may include at least three regions of higher conductivity.
[0020] The bridging portions spanning different regions of lower conductivity may be spaced apart from one another in the length direction of the conductor. This provides a conductor with reduced energy losses.
[0021] One or more regions of lower conductivity may be arranged so as to reduce eddy currents in the conductor. Regions of higher conductivity and regions of lower conductivity are preferably arranged to inhibit transverse current flow in the conductor. Regions of higher conductivity and regions of lower conductivity are preferably arranged to allow longitudinal current flow in the conductor. One or more regions of lower conductivity are preferably arranged to mimic the insulating layer between conductors in a Leeds conductor arrangement. This may be arranged, for example, in a sinusoidal or spiral arrangement. This may be a braided, plaited or woven arrangement.
[0022] An electric machine including a winding may be provided. The winding may include a conductor as described herein. The electric machine optionally includes at least one rotor and at least one stator. The conductor may be arranged in one or more slots in the rotor or the stator. Partitions of the conductor within the one or more slots may have regions with lower electrical conductivity. Partitions of the conductor outside the one or more slots may not have regions with lower electrical conductivity.
[0023] According to a second aspect, there is provided a method of manufacturing a conductor for an electric machine, the method comprising: Two areas of higher conductivity are formed. forming a region of lower conductivity, the region of lower conductivity comprising a conductive material having a plurality of discontinuities in the conductive material such that the region of lower conductivity has a lower conductivity than the region of higher conductivity; The region with lower electrical conductivity is arranged between the two regions with higher electrical conductivity so as to at least partially separate the two regions with higher electrical conductivity along the length direction of the conductor.
[0024] This aspect has the advantage of producing a conductor that reduces energy losses due to eddy currents and skin effect without inhibiting current flow in the length of the conductor.
[0025] Forming the two regions of higher conductivity and / or forming the region of lower conductivity may be performed using one or more additive manufacturing processes.
[0026] Forming the region of lower conductivity may involve depositing particles. Forming the two regions of higher conductivity may involve depositing particles and may involve sintering the deposited particles.
[0027] Forming regions of lower conductivity may involve creating gaps, cracks, or microcracks. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Embodiments of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic illustration of an aircraft including an electrical system; Figure 2is a cross-sectional view of a conductor; Figure 3 is a partially cutaway perspective view of the motor of the first embodiment; Figure 4 It passes through Figure 3 The cross section of the motor; Figure 5 It passes through Figure 3 an enlarged view of a cross section of a conductor of a motor; Figure 6 is a cross section through a portion of the motor of the second embodiment; Figure 7 yes Figure 6 An enlarged view of the slot of the motor; Figure 8 is a graph showing AC losses versus DC losses modeled in different variations of conductors; and Fig. 9 is the cross-section of the conductor passing through the motor. DETAILED DESCRIPTION
[0029] The following detailed description and drawings provide examples of how the invention may be implemented and should not be considered limiting examples, but rather illustrations of how the various features of the conductor may be combined or used. Other alternative variations and combinations will be apparent upon reading the following description in light of the drawings.
[0030] Features of the present invention are defined in the appended claims.While particular combinations of features have been presented in the claims, it will be appreciated that other combinations, such as those provided above, may be used.
[0031] As used herein, the terms: "region of lower conductivity" and "region of higher conductivity" are defined relative to one another in that the conductivity of the region of lower conductivity is lower than the conductivity of the region of higher conductivity. The region of lower conductivity is conductive but offers greater resistance to the flow of electrical current than the region of higher conductivity.
[0032] The conductor of the present invention is configured for use in an electric machine that may be used in an aircraft.
[0033] Figure 1 An aircraft 1 is schematically represented in FIG. The aircraft 1 comprises a prime mover 2 , a shaft 3 and an electric machine 100 in an electrical system 10 .
[0034] The electric machine 100 may be arranged as a generator configured to deliver power to accessories of the aircraft 1 and / or to provide motive force to a propulsion system of the aircraft (such as one or more propellers). The electric machine 100 includes a rotor 101 and a stator 110. The rotor 101 may be configured to carry a plurality of permanent magnets. The stator 110 may include a plurality of electrical conductors. Similarly, the rotor 101 may be configured to carry a plurality of electrical conductors, and the stator 110 may include a plurality of permanent magnets.
[0035] When the rotor 101 rotates about the axis of rotation within the stator 110, the magnetic field of the rotor 101 also rotates. This causes a rotating magnetic field which interacts with the electrical conductor and thus generates a voltage with the electrical conductor in the usual manner.
[0036] As previously mentioned, energy losses generated when passing current through conductor(s) can be detrimental to the performance of the motor. These losses can be due to: the resistance of the wires to the flow of DC electrons; losses due to the skin effect; and losses due to eddy currents. The present invention mitigates these energy losses, particularly those from eddy currents.
[0037] Figure 2 An embodiment of a conductor 500 of the present invention is shown in FIG. Figures 3 to 5 2 shows the conductors installed in the first embodiment of the electric machine 200. Figure 6 and Figure 7 3 shows a conductor 500 installed in a second embodiment of the electric machine 300. Those skilled in the art will appreciate that the conductor 500 may be installed in different variations or embodiments of the electric machine that may not be described or shown herein.
[0038] The conductor or each conductor 500 comprises: two regions of higher conductivity 520; and a region of lower conductivity 510. The regions of lower conductivity 510 comprise a conductive material in which there are a plurality of discontinuities 512 so that the regions of lower conductivity 510 have a lower conductivity than the regions of higher conductivity 520. Figure 2 As shown, the lower conductivity region 510 is arranged between the higher conductivity regions 520 so as to at least partially separate the two higher conductivity regions 520 along the length direction X of the conductor 500 .
[0039] Conductor 500 may be additively manufactured. Conductor 500 may have a microstructure that indicates it has been manufactured using additive manufacturing.
[0040] As used herein, the term "additive manufacturing" refers to any process that forms a three-dimensional object by adding material to the object one layer at a time. Example processes include: photopolymerisation; material jetting; binder jetting; material extrusion processes such as fused filament fabrication; sheet lamination processes such as ultrasonic additive manufacturing and laminated object fabrication; directed energy deposition 3D printing processes such as laser engineering net shaping; and powder bed fusion processes such as direct metal laser sintering, electron beam melting, selective thermal sintering, selective laser melting and selective laser sintering.
[0041] In a preferred arrangement, additive manufacturing may involve depositing particles and sintering the deposited particles, for example, by using an energy beam. Exemplary energy beams include electron beams or electromagnetic radiation, such as laser beams, for sintering or melting powdered materials. A three-dimensional conductor may be formed from a digital model or another electronic data source by an additive process in which successive layers or regions of material are laid down and subsequently solidified. A laser beam or electron beam may be used to fuse previously flattened layers of powder surface into a solid sheet of material. Another layer of powder may be applied on top of the previously fused sheet, and the process may be repeated until a three-dimensional object is built layer by layer. This may be referred to as powder bed fusion (PBF), laser selective melting, or direct laser metal sintering. The additive manufacturing process may be carried out in a chamber filled with an inert gas to prevent unwanted chemical reactions or oxidation of the molten metal.
[0042] The region of higher conductivity 520 of the conductor 500 may include a plurality of sintered particles 521. As such, the region of higher conductivity 520 may have a microstructure indicative of sintering or melting of the particles.
[0043] The region of lower conductivity 510 may include a plurality of particles 511. The particles 511 may be unsintered or partially sintered. The discontinuities may be spaces or pores 512 between the particles 511. Alternatively or additionally, the discontinuities may be manufactured gaps, cracks or microcracks, such as in Figure 5 As shown in the lower conductivity region 510 in the.
[0044] The one or more regions of lower conductivity 510 may include a series of substantially homogeneous particles, such as Figure 2 As shown in the left and right lower conductivity regions 510 with particles 511 and pores 512 in FIG. Alternatively, one or more lower conductivity regions 510 may have a braided, woven or twisted arrangement, such as Figure 2 As indicated at 580. Figure 2Only one braided region 580 of the regions of lower conductivity 510 is shown, but multiple or all regions of lower conductivity 510 in the conductor 500 may be braided, woven, or twisted. The braided, braided, or twisted arrangement 580 may be manufactured using additive manufacturing (optionally involving sintering particles). Thus, the braided, braided, or twisted elongated strands formed in the arrangement may be directly produced in their braided, braided, or twisted configurations by an additive manufacturing process. Thus, a process step of braiding, braiding, or twisting previously unbraided, unbraided, or untwisted strands to form the arrangement 580 may be unnecessary, as the desired structure may be produced in an additive manufacturing process (such as sintering of particles) or any other suitable additive manufacturing process.
[0045] Alternatively or additionally, the regions of higher conductivity 520 themselves may be created in a braided, woven, or twisted configuration, with Figure 2 This is in contrast to the straight extension of the region of higher conductivity 520 shown in FIG. Fig. 9 , wherein the regions of higher conductivity 520 are themselves formed in a braided, woven or twisted configuration. The regions of higher conductivity 520 may provide a nonlinear conductive path through the conductor 500. The regions of higher conductivity 520 may extend substantially in the length direction X of the conductor 500. The regions of higher conductivity 520 may extend such that these regions of higher conductivity deviate from the length direction X in the width direction Y of the conductor 500 and / or in the depth direction Z of the conductor 500. The regions of higher conductivity 520 may cross each other and / or interweave around each other. The configuration in which the regions of higher conductivity 520 are arranged may be a regular pattern or may be an irregular pattern. The regions of higher conductivity 520 may have one or more features as described in any other embodiment described herein. A region of lower conductivity 510 having a matrix or filler type configuration may be provided, with the regions of higher conductivity being arranged in the matrix or filler type configuration. The regions of lower conductivity 510 may surround, be substantially separated from, and / or at least partially disposed between regions of higher conductivity 520. The regions of lower conductivity 510 may maintain the regions of higher conductivity 520 separated from one another. The regions of lower conductivity 510 may have one or more features as described in any other embodiment described herein.
[0046] like Figure 2As shown, the region of lower conductivity 510 may extend in the length direction X of the conductor. The region of lower conductivity 510 may extend substantially parallel to the outer surface of the conductor 500. The region of lower conductivity 510 may extend in the length direction X of the conductor 500. The region of lower conductivity 510 may be substantially uniform along its length. There may be multiple regions of lower conductivity 510. Preferably, the conductor 500 includes at least three regions, preferably at least four, preferably at least five regions of lower conductivity 510. Figure 2 , Figure 5 and Figure 7 , three regions of lower conductivity 510 are shown. The regions of lower conductivity 510 may be evenly spaced apart from each other, aligned with each other, and / or parallel to each other. The regions of lower conductivity 510 may be arranged so that they do not intersect each other. The regions of lower conductivity 510 may be spaced apart from each other in the width direction Y of the conductor 500. The regions of lower conductivity 510 may extend in the depth direction Z of the conductor 500. The regions of lower conductivity 510 may extend partially or completely along the depth of the conductor 500.
[0047] The conductor 500 may be configured to have a substantially uniform cross-section along its length. The conductor 500 may have a substantially elongated or flat cross-section. The conductor 500 may have a rectangular cross-section, for example, as shown in the figure. In the case where the conductor 500 has an elongated cross-section, two longer sides defining the cross-section and two shorter sides defining the cross-section, one or more or each region 510 of lower conductivity may be arranged to extend partially or completely from one longer side of the conductor 500 to another longer side of the conductor 500. The regions 510 of lower conductivity may be equally spaced between the shorter sides of the conductor 500. Those skilled in the art will appreciate that other shapes and configurations of the conductor 500 are possible.
[0048] The conductor 500 may have a substantially uniform chemical composition along its length, width, and / or depth. The conductive material of the region of lower conductivity 520 may have substantially the same chemical composition as the material of the region of higher conductivity 510.
[0049] For example Figure 2 As shown, one or more bridge portions 530 may be arranged to span or pass through (multiple) lower conductivity regions 510 to mechanically connect higher conductivity regions 520 to each other. The bridge portions 530 spanning or passing through different lower conductivity regions 510 may be spaced apart from each other in the length direction X of the conductor 500, for example, as shown in FIG. Figure 2As shown. Providing one or more bridge portions 530 can improve the structural characteristics of the conductor 500. Likewise, the conductor 500 can be free of the bridge portion 530. The conductor 500 without the bridge portion 530 can reduce the loss.
[0050] The one or more regions of lower conductivity 510 may be arranged to reduce eddy currents within the conductor 500, for example by providing a resistive barrier to current flow in directions other than the length X in the conductor 500. The regions of higher conductivity 520 and the regions of lower conductivity 510 are preferably arranged to inhibit lateral current flow within the conductor 500. The regions of higher conductivity 520 and the regions of lower conductivity 510 are preferably arranged to allow current flow in the longitudinal or lengthwise direction within the conductor 500. The one or more regions of lower conductivity 510 are preferably arranged to mimic an insulating layer between conductors in a Leeds conductor arrangement. This may be arranged, for example, in a sinusoidal or spiral arrangement.
[0051] As previously described, conductor 500 may be used in various embodiments of electric machines. Figure 3 FIG. 2 shows a partial cross-sectional view of a first embodiment of a motor 200. The motor 200 of the first embodiment may include a rotor 201 and a stator 210. Figure 1 Compared to the motor shown in , the rotor 201 can be arranged outside the stator, but those skilled in the art will understand that variations in the relative arrangement and configuration of the rotor 201 and the stator 210 are permissible for the present invention. The rotor 201 may include a plurality of fixed magnets 202. The stator 210 may include a plurality of posts 211. The (multiple) conductors 500 may be arranged in a winding around one or more posts 211. The (multiple) conductors 500 may be arranged to surround one or more posts 211 in a spiral or substantially spiral arrangement. As shown in FIG. Figure 4 and Figure 5 As shown, the conductor 500 can be wound to stack on itself. In the case where there are multiple conductors 500, the conductors 500 can be stacked on each other. In the case where the conductor 500 has an elongated cross-section, such as a rectangular cross-section, the longer sides of the conductors 500 can be juxtaposed or aligned with each other.
[0052] Along the length direction X of the conductor 500, there may be at least one sub-region without any region of lower conductivity 510. The at least one sub-region without any region of lower conductivity 510 may be a sub-region of the conductor that is not subjected to the highest electromagnetic field. Figure 3In an embodiment of the present invention, the winding may have a first partition 508 between the posts 211 and / or the rotor 201 and a second partition 509 outside the posts 211 and / or the rotor 201. The first partition 508 may have a substantially straight shape. Specifically, the conductor(s) in the first partition 508 may be substantially straight. The second partition 509 may be substantially curved. Around each post 211, two first partitions 508 and two second partitions 509 may be provided, and the two first partitions and the two second partitions may together surround the post 211 in a circular arrangement. The first partition 508 may be subjected to a higher magnetic field than the second partition 509. The conductor(s) 500 in the first partition 508 may include one or more regions 510 of lower conductivity. The conductor(s) in the second partition 509 may be free of regions 510 of lower conductivity. The conductor(s) 500 in the second partition 509 may include regions 520 of higher conductivity, substantially contain regions of higher conductivity, or consist of regions of higher conductivity.
[0053] As an alternative or in addition to the distribution of regions in the first partition 508 and the second partition 509, the one or more conductors 500 may have no regions of lower conductivity 510 in the radially outer region of the winding and may have only regions of higher conductivity 520. In the radially inner region of the winding, the one or more conductors 500 may include regions of lower conductivity 510 and regions of higher conductivity 520. In the radially inner region of the winding, the one or more conductors 500 may include a distribution of regions of lower conductivity 510 and regions of higher conductivity 520 as described with respect to the first partition 508 and the second partition 509.
[0054] Figure 6 A second embodiment of the motor 300 is shown in FIG. The motor 300 of the second embodiment may include a rotor 301 and a stator 310. Figure 3 Compared to the motor shown in , the rotor 301 can be arranged inside the stator 310, but those skilled in the art will understand that changes in the relative arrangement and configuration of the rotor 301 and the stator 310 are permissible for the present invention. The rotor 301 may include a plurality of fixed magnets. The stator 310 may include a plurality of slots 311. (Multiple) conductors 500 may be disposed in the plurality of slots 311. Each slot 311 may include an inner section 315 and an outer section 316, such as Figure 7As shown. The conductor 500 may be arranged in each of the inner section 315 and the outer section 316. In the case where the conductor or each conductor 500 has an elongated configuration, the conductor or each conductor 500 may be oriented to extend in the direction of the slot 311 it occupies, i.e. in the radial direction of the motor 300. The conductor or each conductor 500 may be configured to be substantially aligned with the inner wall of the slot 311 it occupies. The areas 510 of lower conductivity may be spaced and distributed equidistantly from each other, for example as Figure 7 As shown. However, in the motor of the second embodiment, the regions of lower conductivity 510 may be concentrated towards the radially inner side of the slot or each slot 311. This may mitigate eddy currents that would otherwise exist in these inner regions. The radially outer region of the slot or each slot 311 may be free of regions of lower conductivity 510, or may include or consist of regions of higher conductivity 520.
[0055] As will be appreciated by those skilled in the art from the description and drawings, the conductor 500 of the present invention has the advantage of reducing energy losses from eddy currents and skin effect while allowing sufficient current to flow through the conductor 500 in the intended direction. In some embodiments, such as in an inverter driven machine operating at a fundamental frequency of 1 kHz, the conductor 500 of the present invention has the advantage of reducing energy losses from eddy currents. The conductor 500 is also easy and inexpensive to manufacture due to its simplicity and because the arrangement facilitates additive manufacturing, optionally using a single particle starting material.
[0056] Figure 8 is a model showing the performance of two examples relative to the claimed conductor. Axis X is the International Annealed Copper Standard ("IACS") of the layers within the conductor, and axis Y is the energy loss percentage. Segment 70 represents AC losses, and segment 71 represents DC losses. Figure 8 A comparison of three conductors is shown: a conventional copper rod with homogeneous copper but no regions of lower conductivity ("100%", referring to 100% IACS of homogeneous copper), and an example with a perfect insulation layer but no regions of lower conductivity between homogeneous copper regions ("0%", referring to 0% IACS of a perfect insulation layer). In terms of energy loss, the performance of an embodiment of the claimed conductor ("50%", referring to 50% IACS of regions of lower conductivity between homogeneous copper regions) is between these two examples. Figure 8As shown, embodiments of the claimed conductors outperform standard bar copper (100%) while being easier and cheaper to manufacture than Litz wire or other laminate or insulation alternatives. The conductivity along the length of the homogenous copper is the same in all of these arrangements. However, due to the presence of areas of lower conductivity and insulation layers and having a non-zero cross section along the width of the conductor, the lengthwise conductivity of the conductor as a whole may vary between the three conductors shown in the figure.
[0057] Although specific forms and arrangements of conductors, motors, and methods have been described and shown in the drawings, it should be understood that various aesthetic, structural, and operational changes may be made to the aspects and embodiments shown while still performing the functions of the invention as defined in the appended claims. Other variations of the conductors shown and described may be envisioned without departing from the scope of protection as defined in the appended claims.
[0058] When the word "or" appears, it should be interpreted as "and / or" such that the mentioned items are not necessarily mutually exclusive and can be used in any appropriate combination.
[0059] Reference signs used in the claims should be construed as merely a guide to the possible embodiment or embodiments and should not be construed as limiting the scope of the claims.
Claims
1. A conductor for a motor, the conductor comprising: two areas of higher conductivity; as well as A region of lower conductivity having a plurality of discontinuities in the conductive material such that the region of lower conductivity has a lower conductivity than the regions of higher conductivity; The region with lower electrical conductivity is arranged between the regions with higher electrical conductivity so as to at least partially separate the regions with higher electrical conductivity along the length direction of the conductor.
2. The conductor according to claim 1, wherein The conductor is additively manufactured.
3. A conductor as claimed in claim 1 or claim 2, wherein: The conductive material has substantially the same chemical composition as the material of the regions of higher conductivity.
4. A conductor as claimed in any one of the preceding claims, wherein: The lower conductivity regions include a plurality of particles, the discontinuities are pores between the particles, and the higher conductivity regions include a plurality of sintered particles; or, These discontinuities include voids, gaps, cracks or microcracks.
5. A conductor as claimed in any one of the preceding claims, wherein Along the length of the conductor there is at least one longitudinal portion or zone that is free of any areas of lower conductivity.
6. A conductor as claimed in any one of the preceding claims, wherein The region of lower conductivity extends in the length direction of the conductor, substantially parallel to the outer surface of the conductor, and wherein the region of lower conductivity is preferably substantially uniform along its length.
7. A conductor as claimed in any one of the preceding claims, wherein One or more bridge portions are disposed across the lower conductivity region to mechanically and / or electrically connect the higher conductivity regions to each other.
8. A conductor as claimed in any preceding claim, comprising a plurality of regions of reduced electrical conductivity, preferably at least three regions of reduced electrical conductivity.
9. A conductor as claimed in claim 8 when dependent on claim 7, wherein The bridge portions spanning different regions of lower conductivity are spaced apart from one another in the length direction of the conductor.
10. A conductor as claimed in any preceding claim comprising at least three regions of higher conductivity.
11. A conductor as claimed in any one of the preceding claims, wherein The one or more regions of lower conductivity are arranged to reduce eddy currents within the conductor; wherein the regions of higher conductivity and the regions of lower conductivity are preferably arranged to inhibit transverse current flow within the conductor and allow longitudinal current flow within the conductor; and Therein, the one or more regions of lower conductivity are preferably arranged to mimic the insulating layers between conductors in a Leeds conductor arrangement, such as by being arranged in a sinusoidal or spiral arrangement.
12. An electric machine comprising a winding, the winding comprising a conductor as claimed in any one of claims 1 to 11; in, The electric machine includes a rotor and a stator, the conductor is arranged in one or more slots in the rotor or the stator, and a partition of the conductor in the one or more slots has a region with lower electrical conductivity.
13. A method of manufacturing a conductor for an electric machine, the method comprising: Two regions of higher conductivity are formed; as well as forming a region of lower conductivity having a conductive material with a plurality of discontinuities in the conductive material such that the region of lower conductivity has a lower conductivity than the regions of higher conductivity; The region of lower conductivity is arranged between the regions of higher conductivity so as to at least partially separate the regions of higher conductivity along the length of the conductor.
14. The method of claim 13, wherein: Forming the regions of higher conductivity and / or forming the regions of lower conductivity may be performed using additive manufacturing.
15. A method according to claim 13 or claim 14, wherein: Forming the region of lower conductivity involves depositing particles; and / or Forming these regions of higher conductivity involves, among other things, depositing particles and sintering the deposited particles.