Power cable

Abstract

To provide a power cable for reducing shrink back or axial movement of an insulation system relative to a conductor.SOLUTION: A power cable includes: a conductor (2), an insulation system arranged around the conductor (2), a tape arrangement (30) forming an interface between the conductor (2) and the insulation system, the tape arrangement (30) having one or several layers (32, 34) of which a first layer has an inner facing surface arranged to face the conductor (2), where the inner facing surface of the first layer of the tape arrangement (30) is coated with friction-enhancing material.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure generally relates to a power cable comprising a power cable and a tape device having a coating of a friction enhancing material.

Background Art

[0002] A power cable typically comprises a conductor covered by an insulation system including, for example, a semiconductor layer and an insulating layer. The insulation system can move axially relative to the conductor due to thermal shrinkage, particularly in the vicinity of the cable ends or at rigid joints close to conductor joints. As a result, a portion of the conductor may be exposed, i.e., the surrounding insulation system may no longer be present. The length of the exposed conductor is referred to as shrink-back. Shrink-back typically reaches a steady state after several thermal cycles.

[0003] There are several ways to reduce shrink-back. For example, as disclosed in European Patent No. 1158638, respective circumferential grooves connected by anchor elements can be provided at the connection sleeve of the rigid joint and at the end of the insulation system adjacent to the connection sleeve. Nevertheless, it is considered desirable to provide alternative means for reducing the shrink-back or axial movement of the insulation system relative to the conductor.

Summary of the Invention

[0004] An overall object of the present disclosure is to provide a power cable that solves or at least alleviates the problems of the prior art.

[0005] Accordingly, according to the first aspect, there is provided a power cable comprising a conductor, an insulating system disposed around the conductor, and a tape device forming an interface between the conductor and the insulating system, the tape device having one or more layers, wherein a first layer of the tape device has an inward-facing surface disposed so as to face the conductor, and the inward-facing surface of the first layer of the tape device is coated with a friction-enhancing material.

[0006] The friction-enhancing material can adjust the friction between the conductor and the tape device, such as the outward-facing surface of the conductor, and can increase it compared to the case of a tape device without such a coating of the friction-enhancing material. Thereby, shrink-back can be reduced. In other words, the axial contraction force can be better handled. The friction-enhancing material provides good gripping of the conductor. In other words, the coated inward-facing surface of the first layer of the tape device reduces the shrink-back of the insulating system disposed around the conductor. Thereby, the risk of defects due to the shrink-back of the insulating system is reduced.

[0007] In other words, the coating of the friction reinforcement material is disposed in contact with the conductor, such as on the outer or outward-facing surface of the conductor. One or more layers of the tape device are to be understood as being disposed around the conductor. The friction reinforcement material may be coated over the entire inward-facing surface or only over a portion of the inward-facing surface. According to one embodiment, the friction reinforcement material is coated over a majority of the inward-facing surface, for example covering at least 50% of the inward-facing surface. The coating of the friction reinforcement material may form part or at least part of the inward-facing surface. In other words, the coating of the friction reinforcement material may be included in the first layer. The friction reinforcement material may form the inward-facing surface of the first layer or at least part thereof. Thus, the inward-facing surface having the friction reinforcement coating may be disposed in contact with the conductor. Alternatively, the coating of the friction reinforcement material may form a separate layer and be disposed to cover, or at least partially cover, the inward-facing surface of the first layer. Thus, the coating may be formed as a layer separate from the first layer or may be formed to form part of the first layer.

[0008] According to one embodiment, the first layer of the tape device is the innermost layer of the tape device. Thereby, the innermost layer of the tape device is coated with the friction reinforcement material. According to one embodiment, the first layer of the tape device is a single layer of the tape device, and the single layer is coated with the friction reinforcement material.

[0009] According to one embodiment, the tape device comprises a winding layer disposed helically around the conductor. Thereby, the winding layer is disposed around the conductor in a helical arrangement. The winding layer may be, for example, the aforementioned first layer, innermost layer, or single layer of the tape device.

[0010] According to one embodiment, the tape device comprises a longitudinally disposed layer disposed along the longitudinal axis of the conductor. The longitudinally disposed layer may be, for example, the aforementioned first layer, innermost layer, or single layer of the tape device.

[0011] According to one embodiment, the tape device includes a swelling layer. Accordingly, the swelling layer is disposed around the conductor. The swelling layer may be a longitudinal arrangement layer disposed along the longitudinal axis of the conductor. The swelling layer is typically configured to swell when in contact with water. That is, the material of the swelling layer is configured to react upon contact with water to swell into the voids and spaces within the power cable and provide a seal against moisture. The swelling layer may be, for example, the aforementioned first layer, the innermost layer, or a single layer of the tape device.

[0012] According to one embodiment, the tape device is a multi-layer tape device including a first layer that is the innermost layer of the tape device and a second layer disposed radially outside the first layer. The second layer typically directly contacts the first layer. The second layer may or may not contain a friction enhancing material.

[0013] According to one embodiment, the multi-layer tape device includes a winding layer and a swelling layer. Thereby, the winding layer and the swelling layer can be favorably disposed around the conductor with the first layer having an inward-facing surface coated with a friction enhancing material as the innermost layer of the multi-layer tape device.

[0014] According to one embodiment, the swelling layer is the innermost layer of the tape device. Accordingly, the swelling layer can include an inward-facing surface coated with a friction enhancing material. For example, in the multi-layer tape device, the swelling layer may be disposed radially inward of the aforementioned winding layer. Accordingly, the winding layer may be disposed to fix the swelling layer in place. Thus, the tape device can include at least two separate layers, namely the swelling layer and the winding layer, with the swelling layer being the innermost layer.

[0015] According to one embodiment, the winding layer is the innermost layer of the tape device. Thus, the winding layer can have an inward-facing surface coated with a friction-enhancing material. For example, the winding layer may be disposed radially inward of the aforementioned swelling layer in a multi-layer tape device. Thus, the swelling layer may be arranged to fix the winding layer in place. According to one embodiment, the winding layer is the outermost layer of the tape device.

[0016] According to one embodiment, the friction-enhancing material contains at least 25 wt% of a polymer. According to one embodiment, the friction-enhancing material contains at least 50 wt% of a polymer. The polymer may be a copolymer such as an ethylene-based copolymer. For example, it may be EVA (ethylene-vinyl acetate) with a VA content of, for example, 10 wt% to 50 wt%, or an ethylene acrylic rubber such as EEA (ethylene ethyl acrylate) or EBA (ethylene butyl acrylate). Alternatively, the polymer may be a graft copolymer such as graft polyethylene, for example maleic anhydride graft polyethylene. Alternatively, the polymer may be an elastomer or rubber, for example EPDM (ethylene propylene diene monomer rubber) or EPR (ethylene propylene rubber).

[0017] According to one embodiment, the friction-enhancing material, typically a polymer-based material, contains carbon black. Thereby, the conductivity of the friction-enhancing material can be adjusted.

[0018] According to one embodiment, the coefficient of friction between the coated friction-enhancing material and the conductor is at least 0.25. Such a coefficient of friction is beneficial for achieving the necessary friction between the conductor, such as the outward-facing surface of the conductor, and the tape device. For example, such a coefficient of friction conveniently reduces the shrink-back of a power cable. In other words, the friction-enhancing material is selected such that the coefficient of friction between the coated friction-enhancing material and the conductor is at least 0.25, taking into account the material of the conductor.

[0019] According to one embodiment, the coefficient of friction between the coated friction enhancement material and the conductor is at least 0.30 or at least 0.35. For example, the coefficient of friction between the coated friction enhancement material and the conductor is between 0.25 and 2.0, such as between 0.30 and 1.5. For example, the coefficient of friction between the coated friction enhancement material and the conductor is between 0.25 and 1.0, such as between 0.30 and 0.95 or between 0.30 and 0.75. For example, in an embodiment where the friction enhancement material is a polymer, such as a copolymer such as the ethylene-based copolymers exemplified above, the two contacting surfaces, namely the coated inner surface and the conductor, have an interaction that prevents or impedes one surface from sliding on the other surface, and such an interaction is approximately proportional to the force pressing one surface against the other surface. That is, the microscopic forces involved are molecular interactions at the microscopic scale between the contact points between the two surfaces. According to at least one embodiment, the friction enhancement material does not form a chemical bond with the conductor. That is, according to at least one embodiment, the friction enhancement material is not an adhesive.

[0020] According to one embodiment, the tape device has an outer surface disposed in contact with the insulation system, and the coefficient of friction between the coated friction enhancement material and the conductor is less than the coefficient of friction between the outer surface and the insulation system.

[0021] According to one embodiment, the conductor is a profile wire conductor having a central longitudinal axis and comprising individual profiled wires arranged in concentric wire layers around the central longitudinal axis. In the case of a profile wire conductor, also called a keystone wire conductor, the individual profiled wires are shaped so that a very high degree of filling is achieved when the profiled wires are twisted into concentric wire layers (e.g., by a twisting machine). Thus, the profiled wires are combined almost seamlessly into a circular conductor. The individual twisted profiled wires may be arranged helically along the central longitudinal axis, and the coating of the friction enhancing material on the inward facing surface of the first layer contacts the outermost wire layer and thus follows the twist of the profiled wires of the outermost wire layer. Thereby, the coating of the friction enhancing material extends longitudinally along the profile wire conductor and also extends circumferentially along the profile wire conductor, resulting in an increase in friction both longitudinally and circumferentially along the profile wire conductor.

[0022] According to one embodiment, the insulation system comprises a semiconductor layer arranged in contact with a tape device. Thus, the insulation system can comprise a semiconductor layer (or, semiconductor conductor shield) arranged closest to the conductor, i.e., closest with respect to the insulation system. Typically, the insulation system further comprises an insulating layer, or electrical insulation layer, arranged outside the semiconductor layer in contact with the semiconductor layer. Optionally, the semiconductor layer is a first semiconductor layer, and the insulation system further comprises a second semiconductor layer (or, semiconductor insulation shield) arranged outside the insulating layer in contact with the insulating layer. Optionally, the power cable or insulation system further comprises one or more outer layers arranged outside the second semiconductor layer, such as, for example, a metal shield and / or a sheath or jacket.

[0023] The semiconductor layer and / or the insulating layer may contain a thermosetting polymer. The thermosetting polymer may be, for example, XLPE, crosslinked ethylene propylene diene monomer rubber (EPDM), or crosslinked ethylene propylene rubber (EPR). The semiconductor layer typically contains a conductive compound such as carbon black, for example.

[0024] According to one embodiment, the semiconductor layer and / or the insulating layer are thermoplastic, that is, formed from a thermoplastic composition containing, for example, polypropylene, LDPE, and / or LLDPE.

[0025] The semiconductor layer and / or the insulating layer may be layers formed by extrusion.

[0026] According to one embodiment, the insulation system has a thickness exceeding 8 mm. For example, the insulation system has a thickness between 8 mm and 45 mm, such as a thickness between 8.3 mm and 38 mm, or a thickness between 8.8 mm and 40.5 mm. The coating of the friction reinforcement material is particularly efficient for reducing the shrink-back of the insulating layer of such a relatively thick insulation system. For example, the semiconductor layer (or semiconductor conductor shield) has a thickness between 0.3 mm and 3 mm, and the insulating layer has a thickness between 8 mm and 35 mm. According to one embodiment, the second semiconductor layer (or semiconductor insulation shield) has a thickness between 0.5 mm and 2.5 mm.

[0027] According to one embodiment, the tape device has a radial spread between 0.05 mm and 1 mm, such as between 0.1 mm and 0.2 mm or between 0.1 mm and 0.8 mm. In other words, the tape device may have a thickness between 0.05 mm and 1 mm, or a thickness between 0.1 mm and 0.2 mm. In the case of an embodiment having a plurality of tape layers, the innermost tape layer is provided with a friction reinforcement material on its inward-facing surface.

[0028] The tape device is sometimes called a conductor tape device. The tape device is typically tightly arranged on the conductor, and a coating of friction-enhancing material is pressed against the outer surface of the conductor. For example, referring to the foregoing embodiment where the conductor is a profile wire conductor, the tape device is arranged to fix the individual twisted profile wires while bringing about an increase in friction due to the coating of friction-enhancing material.

[0029] According to one embodiment, the coating of friction-enhancing material projects radially inward from the inner-facing surface of the first layer. Thereby, the aforementioned friction between the conductor and the tape device can be further increased.

[0030] The power cable may be, for example, a high-voltage power cable for voltages higher than 72 kV. According to one example, the power cable is a high-voltage power cable or an extra-high voltage cable for voltages higher than, for example, 450 kV, or higher than 550 kV, or higher than 800 kV.

[0031] The power cable may be an AC power cable or a DC power cable, such as, for example, a high-voltage direct current (HVDC) cable.

[0032] According to a second aspect, a method for manufacturing at least a part of a power cable is provided. The method includes · providing a conductor, · coating the first surface of the tape device with a friction-enhancing material or coating the conductor with a friction-enhancing material, · arranging the tape device on the conductor such that the first surface becomes the inner-facing surface facing the conductor and the like.

[0033] The effects and features of the second aspect are substantially the same as the effects and features described above in relation to the first aspect. The embodiments mentioned in relation to the first aspect, particularly those mentioned in relation to the tape device and the friction enhancement material, are generally applicable to the second aspect. Accordingly, the coating of the friction enhancement material is arranged to contact the conductor, such as the outer-facing surface of the conductor. That is, the first surface of the tape device contacts the coating of the friction enhancement material.

[0034] According to one embodiment, the coating is carried out by spray coating, for example, by spray coating the friction enhancement material onto the first surface of the tape device or onto the conductor. Alternatively, the coating is carried out by extruding a string of the friction enhancement material onto the conductor. According to one embodiment, the first tape layer of the tape device comprising the coating of the friction enhancement material is first arranged on the conductor, and then the second tape layer of the tape device is arranged on top of the first tape layer. The second tape layer may or may not include the coating of the friction enhancement material.

[0035] According to one embodiment, the method further comprises · wrapping the tape device with an insulation system and further includes.

[0036] The insulation system may be the insulation system described in relation to the first aspect.

[0037] In general, all terms used in the claims should be construed according to their ordinary meaning in the art, unless specifically defined otherwise herein. References to elements, devices, components, means, etc. should all be construed non-exclusively as referring to at least one instance of that element, device, component, means, etc., unless specifically stated otherwise.

[0038] Next, specific embodiments of the concept of the present invention will be described as examples with reference to the accompanying drawings.

Brief Description of the Drawings

[0039]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

MODE FOR CARRYING OUT THE INVENTION

[0040] Next, the concept of the present invention will be further fully described below with reference to the accompanying drawings showing exemplary embodiments. However, the concept of the present invention can be embodied in many different forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided by way of example so that this disclosure is thorough and complete and fully conveys the scope of the concept of the present invention to those skilled in the art. Throughout the specification, like numbers refer to like elements.

[0041] Figure 1 shows an example of a power cable 1. In Figure 1, a radial cross-section of the power cable 1 is shown. The radial cross-section is a cross-section in the radial direction r of the power cable 1, that is, a cross-section perpendicular to the central longitudinal axis 200 (better shown in Figure 4). The power cable 1 may be defined, for example, by cylindrical coordinates (the radial distance r, the azimuth angle φ which is an angle along the circumferential direction, and the axial coordinate along the longitudinal axis 200).

[0042] The power cable 1 includes a conductor 2, an insulating system 5 arranged around the conductor 2, and a tape device 30 that forms an interface between the conductor 2 and the insulating system 5.

[0043] The insulating system 5 in Figure 1 includes a first semiconductor layer (or semiconductor conductor shield) 3 arranged closest to the conductor 2. Further, the insulating system 2 includes an insulating layer (electrical insulating layer) 4 that contacts the first semiconductor layer 3 and is arranged outside the first semiconductor layer 3. Further, the insulating system 5 may include a second semiconductor layer (or semiconductor insulating shield) 9 that contacts the insulating layer 4 and is arranged outside the insulating layer 4. Thus, the semiconductor conductor shield 3 can be called the inner semiconductor layer 3, and the semiconductor insulating shield 9 can be called the outer semiconductor layer 9.

[0044] Optionally, the power cable 1 may include one or more outer layers arranged outside the insulating system 5, such as a waterproof barrier 7, for example a metal shield, and a sheath or jacket layer 11.

[0045] The semiconductor layers 3, 9 and / or the insulating layer 4 may include a thermosetting polymer. The thermosetting polymer may be, for example, XLPE, cross-linked ethylene propylene diene monomer rubber (EPDM), or cross-linked ethylene propylene rubber (EPR). The semiconductor layers 3, 9 typically include a conductive compound such as carbon black, for example.

[0046] According to one embodiment, the semiconductor layers 3, 9 and / or the insulating layer 4 are thermoplastic, i.e., formed from a thermoplastic composition containing at least one of polypropylene, LDPE, and LLDPE.

[0047] Referring to FIG. 2, an enlarged view of the semiconductor conductor shield 3 of the conductor 2, the tape device 30, and the insulating system 5 of FIG. 1 is shown. In the exemplary embodiment of FIG. 2, the tape device 30 is a multi-layer tape device, comprising two layers 32, 34, wherein the first layer 32 is the innermost layer 32 of the tape device 30, and the second layer 34 is the outermost layer 34 of the tape device 30. The first layer 32 has an inward-facing surface 32a arranged to face the conductor 2, and the conductor 2 has an outward-facing surface 2a arranged to face the tape device 30. In other words, the inward-facing surface 32a of the first layer 32 of the tape device 30 faces the outward-facing surface 2a of the conductor 2. The inward-facing surface 32a of the first layer 32 of the tape device 30 may be arranged to at least partially contact the outward-facing surface 2a of the conductor 2. The inward-facing surface 32a is coated with a friction-enhancing material 33, and the friction-enhancing material 33 is arranged in contact with the outward-facing surface 2a of the conductor 2 (shown better in FIG. 3).

[0048] FIG. 3 is an enlarged cross-sectional view of a portion of the conductor 2 and the tape device 30 of FIG. 2. More specifically, the friction-enhancing material 33 is coated on the inward-facing surface 32a of the first layer 32 of the tape device 30, and thus arranged in contact with the outward-facing surface 2a of the conductor 2. The coating of the friction-enhancing material 33 is shown here as a coherent or continuous coating on the inward-facing surface 32a, but it may be a discontinuous or intermittent coating. Thus, in the intermittent spaces between the coatings, the inward-facing surface 32 may contact the outward-facing surface 2a of the conductor 2, i.e., a coating of the friction-enhancing material 33 need not be arranged between them. Also as shown in FIG. 3, the second layer 34 includes an outward-facing surface 34b facing away from the conductor 2 and an inward-facing surface 34a facing towards the conductor 2. The inward-facing surface 34a of the second layer 34 is arranged in contact with the first layer 32 in the example of FIG. 3.

[0049] Figure 4 is a side view of the conductor 2 and the tape device 30 of FIG. 2. As shown in FIG. 4, the second layer 34 is a winding layer arranged in a spiral around the conductor 2, and the first layer 32 is arranged longitudinally along the longitudinal axis 200 of the conductor 2. Here, the first layer 32 is preferably a swelling layer configured to swell when contacting water. Therefore, in the example of FIG. 4, the swelling layer is the innermost layer of the tape device 30 and is provided with a coating of a friction enhancing material (not shown in FIG. 4).

[0050] Figure 5 shows a cross-section of another embodiment of the tape device 130. The tape device 130 of FIG. 4 may be used instead of the tape device 30 of the power cable 1 of FIG. 1.

[0051] The tape device 130 includes a layer corresponding to the aforementioned first layer. That is, the tape device 130 includes a first layer 132 having an inward-facing surface 132a arranged to face the conductor 2 or the outer surface 2a of the conductor 2. The inward-facing surface 132a is coated with a friction enhancing material 133 in a corresponding manner as shown for the tape device 30 of FIG. 3.

[0052] Except for the coating of the friction enhancing material 133 (which may or may not be regarded as a separate layer of the tape device 130), the first layer 132 is a single layer of the tape device 130 in the exemplary embodiment of FIG. 5.

[0053] The first layer 133 of the tape device 130 may correspond to either the winding layer or the swelling layer of FIG. 4, or a combination thereof (i.e., a swelling layer arranged in a spiral around the conductor 2). Therefore, according to at least one example, the winding layer is the innermost layer of the tape device 130 and is provided with a coating of the friction enhancing material 133.

[0054] The coatings 33, 133 of the aforementioned friction enhancement materials typically contain at least 25 wt% of a polymer, or at least 50 wt% of a polymer. Thereby, the coefficient of friction between the coated friction enhancement materials 33, 133 and the conductor 2 can be made at least 0.25. Such a coefficient of friction is beneficial for achieving the necessary friction between the conductor 2, such as the outer surface 2a of the conductor 2, and the tape devices 30, 130. For example, such a coefficient of friction advantageously reduces the shrink-back of the power cable 1 in FIG. 1. In other words, the coating of the friction enhancement material interacts with the conductor 2 or the outer surface 2a of the conductor. Thereby, the frictional force and / or torsional force between the conductor 2 and the tape devices 30, 130, and further the insulation system 5 increases, and the axial contraction force decreases. Therefore, the coatings 33, 133 of the friction enhancement materials reduce the shrink-back of the insulation system 5 disposed around the tape devices 30, 130 and the conductor 2. The polymer is preferably a copolymer such as an ethylene-based copolymer, for example, EVA (ethylene-vinyl acetate) with a VA content of, for example, 10 wt% to 50 wt%, or an ethylene acrylic rubber such as EEA (ethylene ethyl acrylate) or EBA (ethylene butyl acrylate).

[0055] Referring briefly to FIG. 3 again, the tape device 30 has an outer surface 34b (which is the outer surface 34b of the aforementioned second layer 34) disposed in contact with an insulation system (here, the first semiconductor layer shown in FIG. 1). Therefore, the tape device 30 includes an inner surface 32a facing the conductor 2 and an outer surface 34b facing away from the conductor 2. In the exemplary embodiment of FIG. 5, the first layer 130 has a corresponding outer surface 132b. According to an example, the coefficient of friction between the coated friction enhancement materials 33, 133 and the conductor 2 is smaller than the coefficient of friction between the outer surfaces 34b, 132b and the insulation system, as described above. According to an example, the outer surfaces 34b, 132b are at least partially integrated with the insulation system, for example, by at least partially melting into the insulation system.

[0056] Next, referring to FIGS. 6 and 7, an exemplary embodiment of a conductor 201 is shown, which has a central longitudinal axis 200 and comprises individual profile wires 210 twisted together and arranged in concentric wire layers 222, 224 around the central longitudinal axis 200. The individual twisted profile wires 210 are typically arranged in a helical manner along the central longitudinal axis 200 as shown in FIG. 7. The conductor 201 of FIGS. 6 and 7 can replace the conductor 2 of the power cable 1 of FIG. 1.

[0057] The concentric wire layers of the profile wire conductor 201 include at least a first inner wire layer 224 formed from profile wires 214 (only one of which is indicated in FIG. 6) having the same radial cross-sectional shape in both shape and size, and an outermost wire layer 222 formed from profile wires 212 (only one of which is indicated in FIG. 6) having the same radial cross-sectional shape in both shape and size. However, the shape and size of the radial cross-sectional shape of the profile wires 214 of the first inner wire layer 224 may be the same or different compared to the profile wires 212 of the outermost wire layer 222. The profile wire conductor 201 may include two or more inner wire layers. That is, the profile wire conductor 201 may include a plurality of inner wire layers arranged concentrically inside the outermost wire layer 222. As seen in FIGS. 6 and 7, the profile wire conductor 201 includes a central wire having a circular radial cross-sectional shape. Accordingly, the inner wire layer 224, or the plurality of inner wire layers, is arranged between the central wire and the outermost wire layer 222.

[0058] As shown in FIG. 6, a tape device 230, which may be the same as the tape devices 30 and 130 described above, is disposed around the conductor 201, bringing about the advantageous effects as described above. Thus, the coating of the friction-enhancing material on the inward-facing surface of the first layer of the tape device 230 may be disposed in contact with the outermost wire layer 222, and thus can follow the twist of the profile wire 212 of the outermost wire layer 222. Thereby, the coating of the friction-enhancing material extends longitudinally along the profile wire conductor 201 and also extends circumferentially along the profile wire conductor 201, resulting in an increase in friction both longitudinally and circumferentially.

[0059] Next, a method for manufacturing at least a part of a power cable such as the power cable 1 of FIG. 1 will be described with reference to the flowchart of FIG. 8.

[0060] In a first step S10, a conductor is provided. The conductor may be the conductor 2 of FIGS. 1 to 5 or the conductor 201 of FIGS. 6 and 7.

[0061] In an optional second step S20a, the first surface of the tape device is coated with a friction-enhancing material. In an optional second step S20b, the conductor is coated with a friction-enhancing material. The tape device may be any of the tape devices 30, 130, and 230 described with reference to FIGS. 1 to 6.

[0062] In a third step S30, the tape device is disposed on the conductor such that the first surface faces the inward-facing surface facing the conductor. Thus, since the first surface of the tape device is an inward-facing surface such as the innermost inward-facing surface of the tape device, the friction-enhancing material may be coated on the tape device when the tape device is disposed on the conductor. That is, the coating of the friction-enhancing material may be a shared coating between the conductor and the tape device. Thus, the coating of the friction-enhancing material is disposed in contact with the conductor such as the outward-facing surface of the conductor and in contact with the first surface of the tape device, as described above.

[0063] In a fourth optional step S40, the tape device is encapsulated by an insulation system. The insulation system may be the insulation system 5 described with reference to FIG. 1, or alternatively may comprise at least one of the aforementioned layers, namely the first semiconductor layer (or semiconductor conductor shield), the insulation layer (electrical insulation layer), and the second semiconductor layer (or semiconductor insulation shield). The layers of the insulation system are preferably extruded onto the conductor and the tape device.

[0064] The concept of the present invention has been described above mainly with reference to several examples. However, as can be easily understood by those skilled in the art, other embodiments other than the above-described embodiments of the disclosure are equally possible within the scope of the concept of the present invention as defined by the appended claims.

Claims

1. A conductor (2, 201), an insulating system (5) disposed around the conductor (2, 201), and a tape device (30, 130) forming a contact surface between the conductor (2, 201) and the insulating system (5). The power cable (1) is provided with: the tape device (30, 130) has one or more layers (32, 34, 132), and a first layer (32, 132) of the layers (32, 34, 132) has an inward-facing surface (32a, 132a) disposed to face the conductor (2, 201). The inward-facing surface (32a, 132a) of the first layer (32, 132) of the tape device (30, 130) is coated with a friction-enhancing material (33, 133).

2. The first layer (32, 132) of the tape device (30, 130) is the innermost layer of the tape device (30, 130). The power cable (1) according to claim 1.

3. The tape device (30, 130) includes a winding layer (34, 132) spirally disposed around the conductor (2, 201). The power cable (1) according to claim 1 or 2.

4. The tape device (30) includes a swelling layer (34). The power cable (1) according to any one of claims 1 to 3.

5. The swelling layer (34) is the innermost layer of the tape device (30). The power cable (1) according to any one of claims 2 to 4.

6. The winding layer (132) is the outermost layer of the tape device (130). The power cable (1) according to any one of claims 2 to 5.

7. The tape device is a multi-layer tape device including the first layer, which is the innermost layer of the tape device, and a second layer disposed radially outside the first layer. The power cable (1) according to any one of claims 1 to 6.

8. The multi-layer tape device includes the winding layer and the swelling layer. The power cable (1) according to claim 3, 4, or claim 7.

9. The friction-enhancing material (33, 133) contains at least 25% by weight of a polymer. The power cable (1) according to any one of claims 1 to 8.

10. The power cable (1) according to any one of claims 1 to 9, wherein the coefficient of friction between the coated friction reinforcement material (33, 133) and the conductor (2, 201) is at least 0.

25.

11. The tape device (30, 130) has an outer surface (34b, 132b) arranged in contact with the insulation system (5), and the coefficient of friction between the coated friction reinforcement material (33, 133) and the conductor (2, 201) is smaller than the coefficient of friction between the outer surface (34b, 132b) and the insulation system (5). The power cable (1) according to any one of claims 1 to 10.

12. The conductor (201) has a central longitudinal axis (200), and is a profile wire conductor provided with twisted individual profile wires (210, 212) arranged in concentric wire layers (222, 224) around the central longitudinal axis (200). The power cable (1) according to any one of claims 1 to 11.

13. The insulation system (5) includes a semiconductor layer (3) arranged in contact with the tape device (30, 130). The power cable (1) according to any one of claims 1 to 12.

14. A method for manufacturing at least a part of a power cable, comprising: - providing a conductor (2, 201) (S10); - coating a first surface of a tape device (30, 130) with a friction reinforcement material (33, 133) (S20a), or coating the conductor (2, 201) with the friction reinforcement material (33, 133) (S20b); - arranging the tape device on the conductor such that the first surface becomes an inner surface (32a, 132a) facing the conductor (2, 201) (S30). A method including the above steps.

15. - further including wrapping the tape device (30, 130) with an insulation system (5) (S40). The method according to claim 14, further including the above step.

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