Dielectric Properties of Transformer Oils for HVDC Applications
Journal article, 2012

The knowledge of the behavior of electric conductivity in mineral oils for possible applications in HVDC converter transformers is of paramount importance for proper design of their insulation system. This study presents the results of measurements of dielectric properties of various transformer oils by means of frequency response technique as well as time domain measurements, including measurements of ion mobility using the reversal polarity method. Influences imposed by varying the measurement voltage level and temperature are investigated. Some important parameters of the investigated oils, e. g. their conductivities, ion mobilities, ionic concentrations and effective ionic radiuses are compared and discussed. The results show that despite of similarities in various physical parameters of insulating mineral oils available on the market, the dielectric behavior and especially ionic conduction vary greatly between different oil types. Changes of these properties with temperature are characterized by different activation energies.

ion mobility

transformer oil

HVDC converter transformer

dielectric properties


Lijun Yang

Stanislaw Gubanski

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

Yuriy Serdyuk

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

Joachim Schiessling

IEEE Transactions on Dielectrics and Electrical Insulation

1070-9878 (ISSN) 15584135 (eISSN)

Vol. 19 6 1926-1933 6396949

Driving Forces

Sustainable development

Areas of Advance


Materials Science

Subject Categories

Other Electrical Engineering, Electronic Engineering, Information Engineering



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4/5/2022 6