International Congress on Engineering, Sciences and Innovative Technologies (ICESIT 2020) - Kuala Lumpur - Malaysia (2020-02-13)

Electrical Performance Analysis of Palm Oil-Based Carbon Nanotubes Nanofluids for Transformer Application
Petroleum-based mineral oil is used as insulation in transformer since decades due to its insulating features. However, it is non-biodegradable, high installation and maintenance costs, and high flammability. Due to these concerns, natural ester oil is recommended and has huge potential to replace mineral oil as insulation. As nanotechnology have played a very important role in electrical industry and previous studies proved that nanomaterial able to enhance the properties of mineral oil, hence, this paper studies the electrical efficiency of carbon nanotubes (CNT) with nano-sized diameter inserted into palm based oil at various concentrations (0, 0.0125, 0.025, 0.0375, 0.05, 0.125, 0.25 and 0.5 g/L). Dispersion methods, including sonication and drying process were systematically applied for producing stable CNT nanofluids. Several parameters such as electrical properties (AC breakdown voltage) and dielectric properties (dissipation factor, relative permittivity and resistivity) were measured accordingly based on IEC 60156 and IEC 60247 international standards. The test results reveal that the higher concentration of CNTs dispersed in palm oil, the lower AC breakdown voltages produced. At 0.5 g/L concentration, the average of 50 breakdown was 22.30 kV, which is 72.33% decrement compared to palm oil without any nano-filler. Besides, the permittivity and resistivity of CNT nanofluids decrease as concentrations increased, while dissipation factor increase along with CNT concentrations. In order to further support this indication, Raman analysis is measured to relate the behaviour of AC breakdown voltages and chemical structure of CNT nanofluids. Based on the Raman spectra at 2800-3200 cm-1 region, it is shown that the value of total unsaturated fatty acid and total fatty acid decreased as concentrations of CNT increased. This occurrence directly influences the degradation performance of AC breakdown voltages. It can be computed that dispersing CNT with palm based oil may be inappropriate for insulation purposes, however, further investigation on the preparation process or stability of nanofluids may well be recommended in the future.
Miss NUR SABRINA SUHAIMI, Mr. Yin Tan Chong, Dr. Muhamad Faiz Md Din, Mr. Abdul Rashid Abdul Rahman