PERFORMANCE OF INSULATION TESTING FOR POWER TRANSFORMER BY USING MIXTURE OF REFINED BLEACHED DEODORIZED (RBD) CORN AND MINERAL OIL

Abstract

Transformer is one of the most important equipment in electrical power system. Nearly, all high voltage transformers are filled with oil to act as cooling medium and insulator. Generally, petroleum-based mineral oil is used as transformer oil. However, due to environmental concern and life-cycle of mineral oil, renewable resource such as corn oil is chosen as the best option to replace the mineral oil. Past researches have shown that corn oil have an equivalent dielectric properties to substitute the mineral oil as liquid dielectric in electrical power transformer. However, the kinematic viscosity does not fulfill the IEC 60296 standard requirements and need to be improved. This research was carried out the detailed study on dielectric properties of mineral and Refined Bleached Deodorize (RBD) corn oil with follow the method of international electro technical commission number. The results shows that the data of the corn oils is critically compared with that of the mineral oil and appropriate causes for similarities and differences have been discussed. The properties has been observed in this research are dielectric strength, dissipation factor (tan δ), relative permittivity (dielectric constant), kinematic viscosity and breakdown voltage. The comparison results between the mineral oils and RBD corn oil has come out with suggestion that corn oils also can be used as transformer oil.