Comparison of Different Methods for Characterization of DC Conductivity of Insulating Polymers
Paper in proceeding, 2020

Knowledge of the electrical conductivity of polymer insulation materials is important for designing cable components for high-voltage direct-current (HVDC) applications. The aim of this study is to compare three measuring techniques, namely, charging current, surface potential decay (SPD) and dielectric response measurements. The first method is time consuming because it requires that the bulk current through a material is recorded while a direct-current (DC) voltage is applied for a prolonged period of time. The DC conductivity is calculated from the steady state current, which is typically only approached after several hours to days. In SPD experiments, the decay of a surface potential, induced by corona charging, is monitored and utilized
to estimate the field-dependent conductivity from one single measurement. Frequency domain dielectric spectroscopy (FDS) measurements allow to estimate the DC conductivity from the low frequency response. Two materials, low density polyethylene (LDPE) and cross-linked polyethylene (XLPE), were used. The SPD measurements overestimated the conductivities of both materials compared to those obtained by the charging current method for the entire studied range of temperature (30-70 ºC) and electric field (10–50 kV/mm). At the same, FDS measurements underestimated the temperature dependency of the conductivity for both LDPE and XLPE. It was noticed that the SPD technique demonstrated a very good repeatability and required significantly shorter measuring time compared to other methods.

charging current

electric conductivity

dielectric response

Frequency domain dielectric spectroscopy

polymeric insulation

surface potential


Sarath Kumara

Chalmers, Electrical Engineering, Electric Power Engineering

Xiangdong Xu

Chalmers, Electrical Engineering, Electric Power Engineering

Thomas Hammarström

Chalmers, Electrical Engineering, Electric Power Engineering

Amir Masoud Pourrahimi

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Christian Müller

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Yuriy Serdyuk

Chalmers, Electrical Engineering, Electric Power Engineering

Proceedings of the 2020 IEEE 3rd International Conference on Dielectrics, ICD 2020

435-438 9342018
9781728189833 (ISBN)

IEEE International Conference on Dielectrics
Valencia, Spain,

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

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

Areas of Advance


Subject Categories

Polymer Technologies

Other Electrical Engineering, Electronic Engineering, Information Engineering



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