Electrical Conduction In Impregnants For All-film Power Capacitors

Abstract

The conduction properties of some impregnants (monodibenzyltoluene and phenylxylylethane) used in the all‐film capacitors technology are investigated. The intent of this research contribution is to perform detailed investigations of these properties in a substantial range of electric fields (from 10−2 to 102 V μm−1). Measurements of the macroscopic charge transport properties (conductivity, mobility, and viscosity) at low field are reported for the temperature range 293–373 K. Evidence of ionic conduction is found from these results. It is possible to evaluate the ionic dissociation parameter of ionic species [e.g., TBAP (tetrabutylammonium picrate)] by studying solutions of known electrolytes in well‐purified solvents. Combining this information with the corresponding investigation in well‐purified liquids, it is found that the residual ionic conductivity of these fluids corresponds to 10−10–10−11 mol/l equivalent TBAP. In the high‐field region, particular emphasis is given to the quantitative interpreta...