There are not only such solid medium as silicone rubber (SR)

EPDM rubber (EP) and insulating self-adhesive tape

but also such liquid medium as dimethyl silicone oil or polyisobutene (PIB) in high voltage oil-filled cable terminals. The compatibility of liquid and solid mediums is directly related to the stability of insulation performance and reliability of high voltage oil-filled cable terminals. In this paper

the compatibility test among PIB

SR and EP at 120 ℃ is performed for 168 h firstly

then the physical and chemical properties and electrical properties of liquid solid medium index is measured. It is concluded that the compatibility of PIB and SR is superior to that of PIB and EP in accordance with the physical and chemical performance variation characteristics of the liquid and solid medium at different aging time and the that of different liquid and solid medium combination at the same aging time

as well as in combination with the physical meaning of the dielectric performance and comprehension comparison. For defining the compatibility mechanism among PIB

SR and EP

the Materials Studio software is used further in this paper to construct the molecular model and interface structure of liquid and solid medium. The enthalpy values of PIB -SR interface and PIB-EP interface at different temperatures are obtained by molecular dynamics technology. The calculation result shows that when the temperature is increased from 363 K to 393 K

the enthalpy variation of PIB-EP interface is less than 0 and tends to dissolve

while the enthalpy variation of PIB-SR interface is more than than 0. Therefore

the PIB-SR interface is more stable than the PIB-EP interface. The conclusion in this paper can provide a theoretical basis for the selection of liquid and solid medium in high voltage oil-filled cable.