Electrical Characterization of a New Crosslinked Copolymer Blend for DC Cable Insulation
Journal article, 2020

To design reliable high voltage cables, clean materials with superior insulating properties capable of operating at high electric field levels at elevated temperatures are required. This study aims at the electrical characterization of a byproduct-free crosslinked copolymer blend, which is seen as a promising alternative to conventional peroxide crosslinked polyethylene currently used for high voltage direct current cable insulation. The characterization entails direct current (DC) conductivity, dielectric response and surface potential decay measurements at different temperatures and electric field levels. In order to quantify the insulating performance of the new material, the electrical properties of the copolymer blend are compared with those of two reference materials; i.e., low-density polyethylene (LDPE) and peroxide crosslinked polyethylene (XLPE). It is found that, for electric fields of 10–50 kV/mm and temperatures varying from 30 °C to 70 °C, the DC conductivity of the copolymer blend is in the range of 10−17–10−13 S/m, which is close to the conductivity of crosslinked polyethylene. Furthermore, the loss tangent of the copolymer blend is about three to four times lower than that of crosslinked polyethylene and its magnitude is on the level of 0.01 at 50 °C and 0.12 at 70 °C (measured at 0.1 mHz and 6.66 kV/mm). The apparent conductivity and trap density distributions deduced from surface potential decay measurements also confirmed that the new material has electrical properties at least as good as currently used insulation materials based on XLPE (not byproduct-free). Thus, the proposed byproduct-free crosslinked copolymer blend has a high potential as a prospective insulation medium for extruded high voltage DC cables.

surface potential decay

dielectric response

crosslinked polyethylene (XLPE)

cable insulation

copolymer

DC conductivity

trap energy

low-density polyethylene (LDPE)

Author

Sarath Kumara

Chalmers, Electrical Engineering, Electric Power Engineering, Power grids and Components

Xiangdong Xu

Chalmers, Electrical Engineering, Electric Power Engineering, Power grids and Components

Thomas Hammarström

Chalmers, Electrical Engineering, Electric Power Engineering, Power grids and Components

Yingwei Ouyang

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Christian Müller Group

Amir Masoud Pourrahimi

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Christian Müller Group

Christian Müller

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Christian Müller Group

Yuriy Serdyuk

Chalmers, Electrical Engineering, Electric Power Engineering, Power grids and Components

Energies

1996-1073 (ISSN)

Vol. 13 6 1434-1449

Advanced characterization of new insulation materials for next generation of HVDC power cables

Chalmers, 2019-01-01 -- 2020-12-31.

Areas of Advance

Energy

Subject Categories

Polymer Technologies

Other Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.3390/en13061434

More information

Latest update

6/11/2020