Solid Dielectric Barrier in Oil Insulator under Uniform and Non-Uniform Electric Fields

Abstract

This paper presents the dielectric barrier (PVC, PMMA, and glass) breakdown voltage test in transformer oil in uniform field, slight non-uniform field and highly non-uniform field generated by plate-plate, plate-point, and point-point electrodes, respectively. It was found that PVC can withstand the maximum breakdown voltage that is higher than PMMA and glass. The dielectric barrier with 1 mm thick placed next to the high voltage electrode and ground electrode can withstand the higher breakdown voltage than dielectric barrier with 2 mm thick placed next to the ground electrode and at the middle of electrodes. PVC for point-point, plate-point and plate-plate electrodes can withstand the maximum breakdown voltage of 216.5, 195.7 and 181 kV, respectively. The breakdown voltage of solid insulations is different because of the shape of electrode. These results lead to design the solid insulator in transformer oil under uniform and non-uniform electric fields.