Breakdown Voltage of Palm Oil under Inhomogeneous Electric Field

This paper presents the results of research on the breakdown voltages of palm oil under the influence of an inhomogeneous electric field distribution. The field distribution has been obtained using an arrangement of needle-plate electrodes. Three levels of needle sharpness have been considered, by using the sharpness angle of 0 degrees, 45 degrees, and 60 degrees. The high voltage AC and DC with the distance between electrodes of 2.5mm and 5mm have been used during the experiment. The homogeneity of the electric field has been examined through simulation using the free FEMM 4.2 software. The results show that at a certain distance of electrodes considered, the heterogeneity level increases with the increase of the sharpness angle of the needle electrode. The field efficiency of the needle-plate electrodes arrangement with the sharpness angles of 0 degrees, 45 degrees, and 60 degrees were respectively 40.6%, 18.6% and 11.4%. The experiments on the breakdown voltage of the spacing gap using the same sharpness angles indicate that the obtained peak values of the AC breakdown voltage were respectively 25.5kV, 22.0kV, and 19.7kV, whereas for the DC breakdown voltage the values were 41.0kV, 31.1kV, and 27.2kV respectively.