AC Breakdown Voltage and Dielectric Properties of Palm Oil As Insulating Liquid with The Presence of Copper Particles

The performance of liquid insulation in power transformers is susceptible to conductive particles. This paper presents the experimental study of the influence of copper particles of on the AC breakdown voltage and dielectric properties of palm insulating oil (PO). The PO used in this study is the Refined Bleached and Deodorized Olein type (RPDPO). The PO was contaminated with copper particles of various concentrations (0.1g, 0.5g and 1g). The AC breakdown voltage and dielectric properties such as dielectric dissipation factor, relative permittivity, and resistivity were measured in this experiment. Similar experiments were conducted for mineral oil (MO) for comparison purpose. From this study, the AC breakdown voltage of PO and MO reduces with the increase of copper particle concentration. The copper particles having less effect on the AC breakdown voltage of the PO than on MO. This is due to it has a higher viscosity. The relative permittivity and dissipation factor of PO and MO increase with increasing of copper particle concentration while the resistivity shows opposite relationship. The influence of copper particles on PO and MO is significant at higher temperatures than low temperatures. Similar results were observed for MO.