Polymer composition for W and C application with advantageous electrical properties
The invention relates to power cable polymer composition which comprises a single site polyethylene (SSPE), a power cable, for example, a high voltage direct current (HV DC), a power cable polymer insulation, use of a polymer composition for producing a layer of a power cable, and a process for producing a power cable.
1. A non-crosslinked power cable polymer composition consisting essentially of a composition selected from the group consisting of a multimodal single site polyethylene (SSPE) and a multimodal single site polyethylene (SSPE) with one or more antioxidants, wherein the power cable polymer composition is configured to have and has a DC electrical conductivity of 5.0 fS/m or less when measured at 70° C. and 30 kV/mm mean electric field on a 1 mm thick plaque sample consisting of the power cable polymer composition.
2. A power cable polymer composition according to claim 1 , wherein the single site polyethylene has a density of from 930 to 945 kg/m 3 .
3. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition is a thermoplastic power cable polymer composition.
4. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition is a high voltage (HV) and/or extra-high voltage (EHV) power cable polymer composition.
5. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition is a high voltage direct current (HV DC) and/or an extra high voltage direct current (EHV DC) power cable polymer composition.
6. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition has a DC electrical conductivity of 0.05 to 5.0 fS/m when measured at 70° C. and 30 kV/mm mean electric field on a 1 mm thick plaque sample consisting of the power cable polymer composition.
7. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition has a DC electrical conductivity of 4.0 fS/m or less when measured at 70° C. and 30 kV/mm mean electric field on a 1 mm thick plaque sample consisting of the power cable polymer composition.
8. A power cable polymer composition according to claim 1 , wherein the single site polyethylene is a medium density single site polyethylene (MD SSPE).
9. A power cable comprising a conductor which is surrounded at least by an inner semiconductive layer, an insulation layer and an outer semiconductive layer, in that order, wherein the insulation layer consists of the power cable polymer composition according to claim 1 .
10. A power cable polymer insulation consisting of the power cable polymer composition according to claim 1 .
11. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition has a DC electrical conductivity of 0.01 to 3.0 fS/m when measured at 70° C. and 30 kV/mm mean electric field on a 1 mm thick plaque sample consisting of the power cable polymer composition.
12. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition has a DC electrical conductivity of 0.01 to 2.0 fS/m when measured at 70° C. and 30 kV/mm mean electric field on a 1 mm thick plaque sample consisting of the power cable polymer composition.
13. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition has a DC electrical conductivity of 3.0 fS/m or less when measured at 70° C. and 30 kV/mm mean electric field on a 1 mm thick plaque sample consisting of the power cable polymer composition.
14. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition has a DC electrical conductivity of 2.0 fS/m or less when measured at 70° C. and 30 kV/mm mean electric field on a 1 mm thick plaque sample consisting of the power cable polymer composition.
15. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition has a DC electrical conductivity of 1.0 fS/m or less when measured at 70° C. and 30 kV/mm mean electric field on a 1 mm thick plaque sample consisting of the power cable polymer composition.
16. A power cable according to claim 9 , wherein the power cable is a high voltage direct current (HV DC) power cable and/or an extra high voltage direct current (EHV DC) power cable.
17. A power cable polymer insulation according to claim 10 , wherein the power cable polymer insulation is a high voltage direct current (HV DC) power cable polymer insulation and/or an extra high voltage direct current (EHV DC) power cable polymer insulation.
18. A power cable polymer composition according to claim 1 , wherein the single site polyethylene is an MDPE having a density of from 930 to 945 kg/m 3 or an HDPE having a density of more than 945 kg/m 3 .
19. A power cable polymer composition according to claim 1 , wherein the power cable polymer composition consists of the multimodal single site polyethylene.
20. A method for producing a power cable, comprising:
polymerizing at least ethylene and one or more comonomer(s) in the presence of a single site catalyst to produce a non-crosslinked power cable polymer composition consisting essentially of a composition selected from the group consisting of a multimodal single site polyethylene (SSPE) and a multimodal single site polyethylene (SSPE) with one or more antioxidants, the power cable polymer composition having a DC electrical conductivity of 5.0 fS/m or less when measured at 70° C. and 30 kV/mm mean electric field on a 1 mm thick plaque sample consisting of the power cable polymer composition and
producing the cable with the power cable polymer composition.
21. A method according to claim 20 wherein the power cable comprises a conductor surrounded by at least an inner semiconductive layer, an insulation layer and an outer semiconductive layer, in that order, said method further comprising:
producing at least one layer of the power cable with the power cable polymer composition.
22. A method according to claim 21 , wherein the power cable is a direct current (DC) power cable.
23. A method according to claim 21 , further comprising:
producing the insulation layer with the power cable polymer composition.
24. A method according to claim 21 , wherein the insulation layer consists of the power cable polymer composition.
25. A method according to claim 20 , wherein said power cable is a direct current (DC) power cable.