METHOD FOR PRODUCING AN ELECTRICAL POWER DEVICE BY ADDITIVE MANUFACTURING TECHNIQUES

Abstract

A method for producing an electrical power device from subsequently manufactured parts by an additive manufacturing technique includes determining a target spatial distribution of a physical property of the electrical power device, the physical property being an electrical property and/or a mechanical property; forming a part of the electrical power device; selecting a physical property of a subsequent part of the electrical power device corresponding to the determined spatial distribution of the physical property such as to be different from a corresponding physical property of the part; and by means of the additive manufacturing technique, forming the subsequent part such that it is at least partially in contact with the part.

An electrical power device is obtainable by the method, and the electrical power device may be used as an AC or DC insulator in an HVAC or HVDC apparatus.

Claims

1. A method for producing an electrical power device from subsequently manufactured parts by an additive manufacturing technique, the method comprising: determining a target spatial distribution of a physical property of the electrical power device, the physical property being at least one of an electrical property or a mechanical property; forming a part of the electrical power device; selecting a physical property of a subsequent part of the electrical power device corresponding to the determined spatial distribution of the physical property; and forming the subsequent part using the additive manufacturing technique such that it is at least partially in contact with the part.

2. The method according to claim 1, wherein the spatial distribution of the physical property is a target electrical field pattern (E) of the electrical power device when mounted in a given electrical environment, or a target mechanical strength of the electrical power device.

3. The method according to claim 1, the physical property being an electrical property comprising at least one of a dielectric permittivity, an electric conductivity, or a combination thereof.

4. The method according to claim 1, wherein the part and the subsequent part are insulating parts.

5. The method according to claim 1, wherein the selected physical property of the subsequent part is substantially a material inherent property.

6. The method according to claim 1, wherein the part is formed using an additive manufacturing technique.

7. The method according to claim 16, wherein determining the spatial distribution of target mechanical strength of the electrical power device includes identifying a path (P) of principal mechanical stress of the electrical power device; wherein performing the selection of the mechanical property of the subsequent part and the forming of the subsequent part includes forming one or more of the subsequent parts having a mechanical strength equal to or greater than a predetermined strength threshold value along the identified path (P) of principal mechanical stress.

8. The method according to claim 2, wherein performing the selection of the electrical property of the subsequent part and the forming of the subsequent part according to the determined target electrical field pattern (E) includes varying a material ratio of at least two different materials from the forming of the part to the forming of the at least one subsequent part.

9. The method according to claim 16, wherein performing the selection of the mechanical property of the subsequent part and the forming of the subsequent part according to the determined spatial distribution of the target mechanical strength includes varying a material ratio of at least two different materials from the forming of the part to the forming of the at least one subsequent part.

10. The method according to claim 1, comprising forming multiple subsequent parts using an additive manufacturing technique, wherein a material ratio of at least two different materials is varied to obtain the multiple subsequent parts.

11. An electrical power device produced using the method according to claim 1.

12. The electrical power device according to claim 11, comprising an electrical field grading part formed as one or more of the subsequent parts, the electrical field grading part being configured, at a time the electrical power device is subjected to an electrical field, particularly an HVAC or HVDC electrical field, to alleviate an electrical field density of the electrical field.

13. The electrical power device according to claim 11, comprising an elastic relaxation part formed as one or more of the subsequent parts, the elastic relaxation part being configured to transfer an externally applied stress into a plastic deformation of the elastic relaxation part.

14. (canceled)

15. (canceled)

16. The method according to claim 1, wherein the spatial distribution of the physical property is a target mechanical strength of the electrical power device.

17. The method according to claim 1, the physical property being a mechanical property comprising at least one of a mechanical strength, an elasticity, a plasticity, or a combination thereof.

18. The method according to claim 10, wherein the material ratio of the at least two different materials is gradually varied to obtain the multiple subsequent parts.

19. The electrical power device of claim 11, the electrical power device being at least one of an electrical insulator device or an electrical field grading device.

20. A method comprising: providing an electrical power device produced by a process comprising: determining a target spatial distribution of a physical property of the electrical power device, the physical property being at least one of an electrical property or a mechanical property; forming a part (50) of the electrical power device; selecting a physical property of a subsequent part (51) of the electrical power device corresponding to the determined spatial distribution of the physical property; and forming the subsequent part (51) using the additive manufacturing technique such that it is at least partially in contact with the part (50); and using the electrical power device in at least one of an HVAC or HVDC apparatus.

21. The method of claim 20, wherein the electrical power device in at least one of an HVAC or HVDC apparatus further comprises using the electrical power device as at least one of an AC or DC insulator in at least one of an HVAC or HVDC switchgear or an HVAC or HVDC circuit breaker.

22. The method of claim 20, wherein the electrical power device in at least one of an HVAC or HVDC apparatus further comprises using the electrical power device as a field grading device in at least one of an HVAC or HVDC cable joint.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Embodiments of the present disclosure will be described with reference to the accompanying drawings in which:

[0046] FIGS. 1a-1c are schematic sectional views of electrical power devices according to embodiments of the present disclosure;

[0047] FIG. 2 is a schematic perspective view of an electrical power device according to an embodiment of the present disclosure;

[0048] FIG. 3 is a schematic sectional view of an electrical power device according to an embodiment of the present disclosure installed in a switchgear apparatus; and

[0049] FIG. 4 is a schematic sectional view of an electrical power device according to an embodiment of the present disclosure mounted in a cable joint.

DESCRIPTION OF EMBODIMENTS

[0050] FIGS. 1a-1c are each a schematic sectional view of an electrical power device 100. The parts common to the electrical power devices 100 shown in FIGS. 1a-1c are described once and not repeated for the single electrical power devices. The electrical power device 100 has an insulating base body 50 through which a conductor electrode 200 is passed and fixed from both sides. The electrode 200 is e. g. made of a metal material and has a high voltage applied thereto, which is to be insulated by the insulating base body 50 of the electrical power device 10, e. g. vis--vis a ground electrode (not shown). The ground electrode is for example a part of a housing of a gas insulated switchgear (GIS) compartment. In the exemplary case of a GIS, electrical power device 100 needs to be gas-tight from one side to the other (in the drawings, gas-tight in the left-right direction.

[0051] Thus, the electrical power devices 100 in the embodiments shown herein mechanically support the electrode 200, provide an electrical insulating function between ground and phase (phase-to-phase is also common in other types of applications), and provide a mechanical withstand of pressure differences in the GIS application.

[0052] In the embodiments shown in the drawings, the insulating base body 50 is formed as a part of the electrical power device 100. The part 50 may be formed, for example, by an additive manufacturing technique such as 3D printing, e. g. by vat photopolymerization, material extrusion, material jetting, powder based 3D printing, or lamination based 3D printing. The part 50 may exhibit defined physical properties of one or more of an electrical property, a mechanical property, a thermal property, a magnetic property. One or more of the physical properties may be substantially uniform; alternatively, one or more of the physical properties may vary throughout the part 50, for example show a gradient behavior. Typically, a gradient behavior of the part 50 is in the direction substantially perpendicular to the running direction of the electrode 200.

[0053] In addition, the electrode 200 or parts of the electrode 200, such as an electrode insert of the electrical power device 100, may also be formed by an additive manufacturing technique that is suitable for processing a metal material, such as powder based 3D printing. The electrode 200 may also be formed in a traditional electrode forming process.

[0054] In each of the embodiments of FIGS. 1a-1c, at least one subsequent part 51, 52, 53, 54 is formed by means of an additive manufacturing technique such as 3D printing, e. g. by vat photopolymerization, material extrusion, material jetting, powder based 3D printing, or lamination based 3D printing.

[0055] The electrical power devices 100 in the embodiments are mainly axially symmetric. Thus, the additive manufacturing may include providing a rotating substrate (e. g., a part of the electrode 200 such as an electrode insert) and moving a 3D printer head along the rotating substrate, i. e. in the two translator directions perpendicular to the axis of rotation. In this way, the parts 50, 51, 52, 53, 54 can be built up. However, the electrical power devices 100 are not limited to an axially symmetric shape and the additive manufacturing method involving a rotating substrate.

[0056] As soon as one of the parts 50, 51, 52, 53, 54 is finished, the part that is to be formed next becomes the subsequent part, as used herein, which refers to its antecedent part. Prior to performing the additive manufacturing process of any of the subsequent parts 51, 52, 53, 54, a physical property, such as an electrical property and a mechanical property, of the respective subsequent part 51, 52, 53, 54 is selected. The physical property may be selected such as to be different from a corresponding physical property of the (antecedent) part. In general, at least one physical property, typically at least one of the electrical property and the mechanical property, is changed (i. e., selected to be different) when transitioning to a subsequent part from its respective antecedent part.

[0057] A physical property of the (antecedent) part need not necessarily be uniform. For example, as mentioned above, a physical property of the part 50 may show a gradient behavior, typically a gradient behavior in a direction substantially perpendicular to the electrode. The respective physical property of the subsequent part 51, 52, 53, 54 may also show a gradient behavior, i. e. be selected such as to be different to the respective physical property in the adjacent region of the (antecedent) part 50.

[0058] In FIG. 1a, on the insulating base body 50, a subsequent part 51 has been applied over the entire radial direction (r-direction) of the electrical power device 100. In the selecting, as an exemplary case, it has been decided to change multiple physical properties, e. g. both the electrical and the mechanical properties. The exemplary subsequent part thus 51 has electrical and mechanical properties selected to be different from those of its antecedent part 50. It could also have been decided to only change one physical property, e. g. one of the electrical and mechanical properties, such that another exemplary subsequent part 51 only has the corresponding property changed in comparison to its antecedent part 50.

[0059] In FIG. 1b, on the insulating base body 50 of the electrical power device 100, a subsequent part 51 has been applied in a part in the radial direction r, and subsequent part 52 has been applied in another part in the radial direction r. Again, as described before with reference to FIG. 1a, the subsequent part 51 has a physical property, such as an electrical property, a mechanical property, or both, different from its antecedent part 50. Likewise, the subsequent part 52 has the corresponding physical property or properties, such as the electrical property, the mechanical property, or both, different from its antecedent part 51.

[0060] FIG. 1c shows another example of an electrical power device 100. On the insulating base body 50, a subsequent part 51 has been applied in a part in the radial direction r. In another part in the radial direction, a stackingin the z-directionof subsequent parts 52 and 53 has been applied. In another part in the radial direction, a subsequent part 54 has been applied. Again, as described before with reference to FIG. 1a, the subsequent part 51 has a physical property, such as an electrical property, a mechanical property, or both, different from its antecedent part 50. Likewise, the subsequent part 52 has the corresponding physical property or properties, e. g. the electrical property, the mechanical property, or both, different from its antecedent part 51. Likewise, the subsequent part 53 has the corresponding physical property or properties, e. g. the electrical property, the mechanical property, or both, different from its antecedent part 52. Likewise, the subsequent part 54 has the corresponding physical property or properties, e. g. the electrical property, the mechanical property, or both, different from its antecedent part 53.

[0061] FIG. 2 shows a schematic perspective view of an electrical power device 100 according to an embodiment of the present disclosure. The electrical power device 100 has a base body 50 made of an insulating material, the base body 50 having an electrode insert 200 of an electrical conducting material. On the base body 50, a layer of insulating material 51 has been applied, the layer 51 forming a subsequent part of the electrical power device (having the base body 50 as the antecedent part), and the insulating material of the layer 51 being selected such as to have a physical property different from a corresponding physical property of the base body. For example, the insulating material of the layer 51 is selected such as to have an electrical property different from a corresponding electrical property of the base body 50, a mechanical property different from a corresponding mechanical property of the base body 50, or both.

[0062] FIG. 3 shows a schematic sectional view of the electrical power device 100 of FIG. 2 in a gas insulated switchgear apparatus. Inner conductive support parts 220a, 220b of the gas insulated switchgear support an electrode attached to the electrode insert 200 of the electrical power device 100, the electrode being on a high voltage. Outer conductive support parts 210a, 210b forming a housing part of the gas insulated switchgear support a radially outer part of the electrical power device 100. A region left and right from the electrical power device 100 in FIG. 3 is filled with insulating gas, such as SF.sub.6 gas, in order to achieve an advantageous insulating behavior.

[0063] The electrical properties of the base body 50 have an insulating behavior sufficient for insulating the electrode 200 vis--vis the housing 210a, 210b. The electrical properties of layer 51 have been selected to allow a field grading of an electrical field present inside the gas insulated switchgear apparatus. As an example, by the field grading properties, the electrical field lines E in FIG. 3 do not end on the insulator surface, preventing an accumulation of charges particularly in HVDC applications.

[0064] In FIG. 3, P denotes an exemplary path of principal mechanical stress of the electrical power device 100. An exemplary force F acts on the electrical power device 100. The mechanical properties of layers 50 and 51 have been selected to allow a mechanical grading of the electrical power device 100 by varying the flexibilities of the materials involved. Thereby, higher overall mechanical strength along the path P is achieved. Not only can the stresses be reduced by such a selected distribution of different materials; also elastic relaxation zones may be implemented where stresses from the outside can be macroscopically transferred into plastic deformation and thus removed from the insulator supporting structure.

[0065] FIG. 4 shows a schematic sectional view of an electrical power device 450 as a part of a cable joint 400, such as a high voltage DC cable joint. In FIG. 4, r denotes the radial direction, whereas z denotes the axial direction. In a powered state, a cable conductor 410 and a cable connector, or deflector, 420 are on a high voltage, whereas a screen 430 is on ground potential. The cable conductor 410 and the cable connector 420 abut on each other in the axial direction z. A cable insulation 445 covers the cable conductor 410, in the axial direction z, up to the cable connector 420. A joint insulation 440 extends from the area of the cable connector 420 up to a predetermined distance in the axial direction z.

[0066] The electrical power device 450 is sandwiched in between cable insulation 445 or the cable connector 420, respectively, on the one side in the radial direction r, and the screen 430 or the joint insulation 440, respectively, on the opposite side in the radial direction r. In the embodiment of FIG. 4, the electrical power device 450 serves as a field grading element, or field grading tube. Furthermore, the electrical power device 450 has to bear a considerable mechanical stress.

[0067] In the embodiment of FIG. 4, for a given geometrical and electrical configuration of the electrical power device 450 in the cable joint 400, a target spatial distribution (a desired spatial distribution) of the electrical field is determined. Likewise, for the given configuration of the electrical power device 450 in the cable joint 400, a target spatial distribution (a desired spatial distribution) of the mechanical strength is determined.

[0068] The electrical power device 450 is manufactured via a method as disclosed herein according to the determined spatial distribution of the electrical field and according to the determined spatial distribution of the mechanical stress. For example, the target electrical field pattern (the desired electrical field pattern) of the electrical power device 450 in the installed state is determined, e. g. by way of simulation. Likewise, for example, a path of principal mechanical stress of the electrical power device 450 is determined, e. g. by way of simulation.

[0069] At least one electrical property, such as a conductivity or a dielectric permittivity, an electric conductivity, or a combination thereof, that complies or comply with the target electrical field pattern for the electrical power device 450 is selected for the corresponding location during the manufacturing process via the additive manufacturing technique.

[0070] Likewise, at least one mechanical property, such as a mechanical strength, an elasticity, a plasticity, or a combination thereof, that complies or comply with the path of principal mechanical stress of the electrical power device 450 is selected for the corresponding location during the manufacturing process via the additive manufacturing technique.

[0071] Thereby, the electrical power device 450 according to the present embodiment of FIG. 4, i. e. the field grading tube 450 for the cable joint 400, is obtained.

[0072] The present disclosure has been mainly described with reference to embodiments; however, a person skilled in the art will readily appreciate that other embodiments than the ones described above are part of the present disclosure, wherein the scope is defined by the appended claims.