A Review of Polyolefin-Insulation Materials in High Voltage Transmission; From Electronic Structures to Final Products.

This review focuses on the use of polyolefins in high-voltage direct-current (HVDC) cables and capacitors. A short description of the latest evolution and current use of HVDC cables and capacitors is first provided, followed by the basics of electric insulation and capacitor functions. Methods to determine dielectric properties are described, including charge transport, space charges, resistivity, dielectric loss, and breakdown strength.

Coarse-Grained Model for Prediction of Hole Mobility in Polyethylene.

Electrical conductivity measurements of polyethylene indicate that the semicrystalline structure and morphology influence the conductivity. To include this effect in atomistic charge transport simulations, models that explicitly or implicitly take morphology into account are required. In the literature, charge transport simulations of amorphous polyethylene have been successfully performed using short oligomers to represent the polymer.

Electronic conductivity of polymer electrolytes: electronic charge transport properties of LiTFSI-doped PEO.

The electronic structure of poly(ethyleneoxide) with and without a common electrolyte lithium bis(trifluoromethane)sulfonimide salt is calculated from first principles. Introducing the salt into the polymer electrolyte significantly reduces the band gap, down to 0.6 eV.

Understanding the Ionic Conduction in Dielectric Polymers at High Electric Fields Using Molecular Dynamics Simulations.

Applying molecular dynamics, we have studied ionic transport in polyethylene at moderate and high electric fields. The ion mobility of a variety of species is calculated and compared with existing theories. It reveals that ion mobility starts to deviate from the Einstein relation and increase roughly linearly with field beyond 100 MV/m, which results in a superlinear increase of the ionic current at high field that is consistent with the experimental results.

First-principle simulations of electronic structure in semicrystalline polyethylene.

In order to increase our fundamental knowledge about high-voltage cable insulation materials, realistic polyethylene (PE) structures, generated with a novel molecular modeling strategy, have been analyzed using first principle electronic structure simulations. The PE structures were constructed by first generating atomistic PE configurations with an off-lattice Monte Carlo method and then equilibrating the structures at the desired temperature and pressure using molecular dynamics simulations. Semicrystalline, fully crystalline and fully amorphous PE, in some cases including crosslinks and short-chain branches, were analyzed.