Towards an ultra-high voltage DC cable insulation – adsorption of charge carriers in polyethylene swegrids-logo

SweGRIDS research area MATERIAL
SweGRIDS project code ML8
Project type PhD
Status completed
Researcher Mattias Karlsson   (webpage)
University KTH (CBH)
Project period 2015-04-07 to 2020-03-31   
Project supervisor Richard Olsson   (webpage)
Industrial sponsors

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Project abstract

This PhD project is aimed at providing a fundamental understanding about DC conductivity of polyethylene-based high voltage direct current (HVDC) cable insulation regarding recently developed metal oxide nanocomposites. The composites show ca. 100 times better insulation capability than neat polyethylene but the mechanism(s) for the improvement is not very well understood. A lower conductivity of the HVDC cable insulation is a key parameter for improving the insulation material that will enable a higher operating voltage, lower the losses and therefore enhance the length of power transmission.

The inorganic particles have been synthesized and surface modified in-house to have well-characterized systems. Improved understanding of conduction in nanocomposites will be obtained by studying new composite systems with different morphologies and surface functionalities of the metal oxide nanoparticles.

Also the effect of polar species (moisture, by-products from crosslinking) on the DC conductivity in the various systems (pristine LDPE and selected nanocomposites) will be studied. Polar molecules, that are present in the crosslinked polyethylene for HVDC cable insulation, will be used to investigate the hypothesis that polar/ionic species are adsorbed onto the particles, thus providing fewer impurities in the polyethylene and lower DC conductivity for the composite.

Summary of work


Study regarding water uptake for magnesium oxide (MgO) low-density polyethylene (LDPE) nanocomposites and its influence on the DC conductivity (published 2017).

The first part for the study of atomic terminations for zinc oxide (ZnO) particles in LDPE nanocomposites have been completed where the growth of ZnO particles with dominantly zinc terminations have been studied (published 2018).


The second part of the study on atomic terminations of ZnO particles in LDPE nanocomposites and its influence on the DC conductivity is ongoing (expected publishing in the beginning of 2020).

The uptake of polar molecules in Al2O3 LDPE nanocomposites and the adsorption of polar molecules on the Al2O3 nanoparticles are studied along with the diffusion of polar molecules that are present in crosslinked polyethylene for HVDC cable insulation materials (expected publishing in the beginning of 2020).

A study regarding the influence of polymer morphology and oxidation in LDPE materials on the DC conductivity is ongoing in collaboration with Chalmers technical university (expected publishing in the beginning of 2020).

A study of synergistic mechanisms for decreased DC conductivity of metal oxide LDPE nanocomposites and polymer blends (delayed publishing, Borealis patent).

Event log

2017. Nordic Insulation Symposium, Västerås, Sweden, “DC Conductivity Measurements of LDPE: Influence of Specimen Preparation Method and Polymer Morphology”.

2017. Participated in the PhD course of synchrotron characterization methods in fibre and polymer technology, DESY, Hamburg, Germany.

2018. Nordic polymer days, Copenhagen, Denmark “Influence of water uptake and polymer morphology on the DC conductivity of metal oxide LDPE nanocomposites”.

2019. Nordic polymer days, Trondheim, Norway “Influence of polymer morphology and oxygen containing species on the DC conductivity for low-density polyethylene”. Received Best Poster award from MDPI “Polymers” journal, for this poster.

Project reference-group

Assoc. Prof. Richard Olsson,  KTH Fibre and Polymer Technology (main supervisor)
Professor Ulf W. Gedde,  KTH Fibre and Polymer Technology (assistant supervisor)
Adjunct Prof. Henrik Hillborg,  ABB Corporate Research (assistant supervisor)
Professor Mikael Hedenqvist,  KTH Fibre and Polymer Technology (assistant supervisor)

MSc etc theses connected to the project

Internship project, “Optimization of manufacturing parameters for the creation of nanocomposites with improved electrical insulation”, A. Boucheron, 2016.

Internship project, “Study of pre-mixing methods to control the absorption of crosslinking by-products in neat polyethylene insulation for High-Voltage Direct Current cables”, B. Gnassounou, 2016.

BSc theses “Synthesis of zinc oxide nanorods via the formation of sea urchin structures”, Y. C. Mamie, 2017.

BSc thesis, “Atomic planes terminations’ impact on DC conductivity of multifaceted ZnO crystal LDPE nanocomposites for HVDC cables”, A. Calamida, 2017.

BSc thesis, “Determination of water content in high voltage direct current (HVDC) cable insulation and its influence on the conductivity”, R. Dahl, E. Lallo and F. Persson, 2018.

MSc thesis, "Silanisation of flakes as high surface area fillers", B. Birdsong

MSc thesis, “Life-time prediction of polymers for sustainable usage”, I. Wacha, 2019.

Publications by this researcher

See alternatively the researcher's full DiVA list of publications, with options for sorting.
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Nanocomposites and polyethylene blends : two potentially synergistic strategies for HVDC insulation materials with ultra-low electrical conductivity
Fritjof Nilsson,   Mattias E. Karlsson,   Ulf W Gedde,   Roland Kadar,   Karolina Gaska,   Christian Mueller,   Per-Ola Hagstrand,   Richard Olsson,   Mikael S. Hedenqvist,   Thomas Gkourmpis.
2021,   Composites Part B: Engineering, vol. 204

Lamellae-controlled electrical properties of polyethylene - morphology, oxidation and effects of antioxidant on the DC conductivity
Mattias E. Karlsson,   Xiangdong Xu,   Henrik Hillborg,   Valter Ström,   Mikael S. Hedenqvist,   Fritjof Nilsson,   Richard Olsson.
2020,   RSC Advances, vol. 10(8)

Solubility and Diffusivity of Polar and Non-Polar Molecules in Polyethylene-Aluminum Oxide Nanocomposites for HVDC Applications
Shima L. Holder,   Mattias E. Karlsson,   Richard S. Olsson,   Mikael S. Hedenqvist,   Fritjof Nilsson.
2020,   Energies, vol. 13(3)

The effect of ZnO particle lattice termination on the DC conductivity of LDPE nanocomposites
Mattias E. Karlsson,   A. Calamida,   Daniel Forchheimer,   H. Hillborg,   Valter Ström,   James M. Gardner,   Mikael S. Hedenqvist,   Richard Olsson.
2020,   MATERIALS ADVANCES, vol. 1(6)

Fundamentals of Polyethylene Composites for HVDC Cable Insulation – Interfaces and Charge Carriers
Mattias E. Karlsson.
2020,   Thesis (PhD), KTH Royal Institute of Technology, TRITA-CBH-FOU 2020:27

Characterization of Reduced and Surface-Modified Graphene Oxide in Poly(Ethylene-co-Butyl Acrylate) Composites for Electrical Applications
Carmen Sanchez,   Martin Wåhlander,   Mattias E. Karlsson,   Diana C. Marin Quintero,   Henrik Hillborg,   Eva Malmström,   Fritjof Nilsson.
2019,   Polymers, vol. 11(4)

Precision electric characterization of LDPE specimens made by different manufacturing processes
X. Xu,   K. Gaska,   Mattias E. Karlsson,   H. Hillborg,   Ulf W Gedde.
2018,   IEEE International Conference on High Voltage Engineering and Application (ICHVE), SEP 10-13, 2018, Athens, Greece

Streamer Inception from Ultra-Sharp Needles in Mineral Oil Based Nanofluids
Mauricio Aljure,   Marley Becerra Garcia,   Mattias E. Karlsson.
2018,   Energies, vol. 11(8)

Erratum to : Aljure, M.; Becerra, M.; Karlsson, E.M. Streamer inception from ultra-sharp needles in mineral oil based nanofluids
Mauricio Aljure,   Marley Becerra Garcia,   Mattias Karlsson.
2018,   Energies, vol. 11(11)

Synthesis of Zinc Oxide Nanorods via the Formation of Sea Urchin Structures and Their Photoluminescence after Heat Treatment
Mattias E. Karlsson,   Yann C. Mamie,   Andrea Calamida,   James M. Gardner,   Valter Ström,   Amir Masoud Pourrahimi,   Richard Olsson.
2018,   Langmuir, vol. 34(17)

DC Conductivity Measurements of LDPE: Influence of Specimen Preparation Method and Polymer Morphology
Mattias Karlsson,   Xiangdong Xu,   Karolina Gaska,   Henrik Hillborg,   Stanislaw Gubanski,   Ulf Gedde.
2017,   25th Nordic Insulation Symposium on Materials, Components and Diagnostics, Västerås, Sweden, June 2017

Influence of water uptake on the electrical DC-conductivity of insulating LDPE/MgO nanocomposites
Fritjof Nilsson,   Mattias Karlsson,   Love K. H. Pallon,   Marco Giacinti,   Richard T. Olsson,   Davide Venturi,   Ulf W Gedde,   Mikael S. Hedenqvist.
2017,   Composites Science And Technology, vol. 152

Publication list last updated from DiVA on 2021-09-18 22:01.

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Last generated: 2021-09-18