SE1600316A1 - A composite power cable filler device and a power cable comprising the same - Google Patents

Description

15 20 25 In case the power cable of SE 530 277 C2 would be installed in ultra deep- water, i.e. at depths starting at 1500 m, the filler walls may collapse during installation due to the large radial forces from tensioners.

SUMMARY In view of the above, an object of the present disclosure is to provide a power cable which solves or at least mitigates existing problems.

There is hence according to a first aspect of the present disclosure provided a power cable filler device adapted to bear against a first power core and a second power core in a power cable, wherein the power cable filler device comprises: a first arced wall which defines a portion of a first circle having a first diameter, a second arced wall defining a portion of a second circle and a third arced wall defining a portion of a third circle, each of the second circle and the third circle having a second diameter which is smaller than the first diameter, wherein a chamber is formed between the first arced wall, the second arced wall and the third arced wall, a first partitioning wall in the chamber, extending between the first arced wall and the second arced wall, and a second partitioning wall in the chamber, extending between the first arced wall and the third arced wall, wherein the first partitioning wall and the second portioning wall are made of a first material and the majority of the first arced wall, the second arced wall and the third arced wall are made of a second material, wherein the first material has a higher stiffness and strength than the second material.

The power cable filler device is hence built by materials of different qualities as a composite filler profile. The first material has high stiffness and strength and is used in the regions where it is needed most for transfer of the external load to the power cores. The second material, with lower strength and stiffness, is used in the rest of the filler profile to reduce its torsional stiffness.

A low torsional stiffness is advantageous in the manufacturing process of a power cable. 10 15 20 25 According to one embodiment a region of the first arced wall which constitutes the continuation of the first partitioning wall and a region of the first arced wall which constitutes the continuation of the second partitioning wall are made of the first material.

According to one embodiment a region of the second arced wall which constitutes the continuation of the first partitioning wall is made of the first material.

According to one embodiment a region of the third arced wall which constitutes the continuation of the second partitioning wall is made of the first material.

It should be noted that any of the above regions may have a wider extension in the tangential direction than the width of the corresponding partitioning wall, or the widths may be equal, or the regions may be narrower.

According to one embodiment the first material is high density polyethylene.

According to one embodiment the second material is medium density polyethylene.

There is according to a second aspect of the present disclosure provided a power cable comprising: an external sheath, a first power core, a second power core, and a third power core enclosed by the external sheath, and three power cable filler devices according to the first aspect presented herein, wherein a first power cable filler device is arranged between the external sheath, the first power core and the second power core, a second power cable filler device is arranged between the external sheath, the second power core and the third power core, and a third power cable filler device is arranged between the external sheath, the first power core and the third power core.

According to one embodiment the second power core, and the third power core are twined.

According to one embodiment the power cable is a subsea power cable. 10 15 20 25 According to one embodiment the power cable is a high voltage power cable.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical ñeld, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, etc., unless explicitly stated otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS The specific embodiments of the inventive concept will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows a cross-sectional view of an example of an example of a power cable filler device; and Fig. 2 shows a cross-sectional view of an example of power cable comprising power cable filler devices shown in Fig. 1.

DETAILED DESCRIPTION The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplifying embodiments are shown. The inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art.

Like numbers refer to like elements throughout the description.

Fig. 1 shows a cross-section of an example of a power cable filler device 1.

Power cable filler device 1 comprises a first arced wall 3, a second arced wall 5 and a third arced wall 7. In cross-section of the power cable filler device 1, the first arced wall 3 defines a portion of a first circle having a first diameter.

Similarly, the second arced wall 5 defines a portion of a second circle and the 10 15 20 25 30 third arced wall 7 defines a portion of a third circle, both the second and the third circle having a second diameter which is smaller than the first diameter.

The first arced wall 3, the second arced wall 5 and the third arced wall 7 of the power cable filler device 1 defines the external surface of the power cable filler device 1.

The first arced wall 3, the second arced wall 5 and the third arced wall 7 form outer walls of a chamber 9.

The power cable filler device 1 has a first partitioning wall 11a and a second partitioning wall 11b. The first partitioning wall 11a extends between the first arced wall 3 and the second arced wall 5, in the chamber 9. The second partitioning wall 11b extends between the first arced wall 3 and the third arced wall 7, in the chamber 9. The two walls 11a and 11b partition the chamber 9 into a number of spaces.

The first partitioning wall 11a and the second partitioning wall 11b are made of a first material. The first material may for example be high density polyethylene. The maj ority of the first arced wall 3, the second arced wall 5 and the third arced wall 7 are made of a second material. The first material has a higher strength and stiffness than the second material. The second material may for example be medium density polyethylene. It should be noted that different material than polyethylene may be used as the first material and the second material.

According to one example, a region R1 of the first arced wall 3 which constitutes or forms the continuation of the first partitioning wall 11a and a region R2 of the first arced wall 3 which constitutes or forms the continuation of the second partitioning wall 11b may be made of the first material. In case the first partitioning wall 11a and the second partitioning wall 11b are separate parts, not forming part of the external structure of the power cable filler device 1, the two regions R1, R2 of the first arced wall 3 are those which bear against a respective partitioning wall 11a and 11b. The regions made of the first material only form a limited portion of the first arced wall 3. 10 15 20 25 30 According to one example, a region R3 of the second arced wall 5 which constitutes or forms the continuation of the first partitioning wall 11a may be made of the first material. A region R4 of the third arced wall 7 which constitutes or forms the continuation of the second partitioning wall 11b may be made of the first material. In case the first partitioning wall 11a and the second partitioning wall 11b are separate parts, not forming part of the external structure of the power cable filler device 1, the regions R3 and R4 of the second arced wall 5 and the third arced wall 7 are those which bear against a respective partitioning wall 11a and 11b. The regions R3, R4 made of the first material only form a limited portion of the second arced wall 5 and the third arced wall 7.

The power cable filler device could according to one example include more than two partitioning walls, for example four partitioning walls, or more than four partitioning walls.

Fig. 2 shows a cross-sectional view of an example of a power cable 13 comprising an external sheath 19, an armour layer 17, a plurality of power cores 15a, 15b, 15c, and three power cable filler devices 1. According to the present example, the power cable 13 comprises three power cores, one for each electrical phase. The power cores 15a-15c comprise electrical conductors for conducting current, and insulation systems for electrically insulating the electrical conductors.

For each power cable filler device 1 the arced wall 3 is arranged adjacent to the armour layer 17, the second arced wall 5 is arranged adjacent to a respective power core 15a-15c and the third arced wall 7 is arranged adjacent to another power core 15a-15c.

The external sheath 19 encloses the armour layer 17 and the armour layer 17 encloses the power cable filler devices 1 and the power cores 15a-15c. It should be noted that according to Variations of the power cable 1, there could be additional armour layers 17, or the power cable could be without armour layers. 10 The power cores 15a-15c are twined along the length of the power cable 1, and the power cable filler devices 1 are twisted as they extend longitudinally between pairs of adjacent power cores 15a-15c.

The power cable filler devices 1 typically have a cross-sectional geometry which is constant along their entire longitudinal extension, or essentially along their entire longitudinal extension.

The power cable 13 may for example be a subsea power cable, in particular a high voltage subsea power cable. It is envisaged that power cable presented herein may be utilised in subsea applications such as subsea power transmission or subsea power distribution.

The inventive concept has mainly been described above with reference to a few examples. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims.

Claims (10)

10 15 20 25 CLAIMS

1. A power cable filler device (1) adapted to bear against a first power core (15a) and a second power core (15b) in a power cable (13), wherein the power cable filler device (1) comprises: a first arced wall (3) which defines a portion of a first circle having a first diameter, a second arced wall (5) defining a portion of a second circle and a third arced wall (7) defining a portion of a third circle, each of the second circle and the third circle having a second diameter which is smaller than the first diameter, wherein a chamber (9) is formed between the first arced wall (3), the second arced wall (5) and the third arced wall (7), a first partitioning wall (11a) in the chamber (9), extending between the first arced wall (3) and the second arced wall (5), and a second partitioning wall (11b) in the chamber (9), extending between the first arced wall (3) and the third arced wall (7), wherein the first partitioning wall (11a) and the second portioning wall (11b) are made of a first material and the majority of the first arced wall (3), the second arced wall (5) and the third arced wall (7) are made of a second material, wherein the first material has a higher stiffness and strength than the second material.

2. The power cable filler device (1) as claimed in claim 1, wherein a region (R1) of the first arced wall (3) which constitutes the continuation of the first partitioning wall (11a) and a region (R2) of the first arced wall (3) which constitutes the continuation of the second partitioning wall (11b) are made of the first material.

3. The power cable filler device (1) as claimed in claim 1 or 2, wherein a region (R3) of the second arced wall (5) which constitutes the continuation of the first partitioning wall (11a) is made of the first material. 10 15 20 25

4. The power cable filler device (1) as claimed in any of the preceding claims, wherein a region (R4) of the third arced wall (7) which constitutes continuation of the second partitioning wall (11b) is made of the first material.

5. The power cable filler device (1) as claimed in any of the preceding claims, wherein the first material is high density polyethylene.

6. The power cable filler device (1) as claimed in any of the preceding claims, wherein the second material is medium density polyethylene.

7. A power cable (13) comprising: an external sheath (19), a first power core (15a), a second power core (15b), and a third power core (15c) enclosed by the external sheath (19), and three power cable filler devices (1) according to any of claims 1-6, wherein a first power cable filler device (1) is arranged between the external sheath (19), the first power core (15a) and the second power core (15b), a second power cable filler device (1) is arranged between the external sheath (19), the second power core (15b) and a third power core (15c), and a third power cable filler device (1) is arranged between the external sheath (19), the first power core (15a) and the third power core (15c).

8. The power cable (13) as claimed in claim 7, wherein the first power core (15a), the second power core (15b), and the third power core (15c) are twined.

9. The power cable (13) as claimed in claim 7 or 8, wherein the power cable (13) is a subsea power cable.

10. The power cable (13) as claimed in any of claims 7-9, wherein the power cable (13) is a high voltage power cable.