Research of the reason to increase stray conductance and tgδ of impregnant of capacitor voltage transformer

Mineral oil was used as the liquid dielectric in electromagnetic device of capacitor voltage transformer (CVT) previously. At present the Alkyl Benzene oil (AB oil) is applied. However, the stray conductance and tg_δ of AB oil were once been larger. This paper studies the practicability of the AB oil as impregnant in the electromagnetic device, and simulated electromagnetic device has been placed in the AB oil and mineral oil separately. Then, specimens were aged for 1440 h. The stray conductance and capacitance for two kinds of specimens (oil) are tested so that the reason of increasing the stray conductance and tg_δ of impregnant can be found