Ester fluid Midel 7131 as PCB-substitute for distribution transformers

Abstract

The electric and dielectric behavior of ester fluid considered as a substitute for PCB is examined. After a short description of the insulating fluid, the authors consider the influence of temperature differences and aging condition of the insulation on the breakdown behavior of the fluid-paper combined dielectric. Furthermore, a comparison of the breakdown and aging behavior of cellulose-ester impregnated and aramid-ester impregnated insulating materials is given. Finally, the influence of partial discharge prestressing on the breakdown behavior of the fluid-paper combined dielectric is shown.<>