This paper gives information on the electrical and physiochemical characteristics of six different types of palm oil compared with traditional mineral oil. We found that natural processed crude palm oil (PO-C) had a higher resistance to AC breakdown voltage than other types of palm oil, including traditional mineral oil. The results of the positive lightning impulse voltage test for PO-C were still the highest compared to other types of palm oil, including traditional mineral oil, at 58.26%. The summarised dissipation factors of all tested crude palm oils were significantly higher than those of mineral oils, which will make the palm oil less insulating, especially in PO-A palm oil (36.197%), where the values were higher than those of other oils, while mineral oil has a slightly increased dispersion factor. For relative permittivity, all palm oils were compared, and it was found that PO-C had a lower relative permittivity than the other oils. In terms of physical and chemical properties, in the moisture content test on all oils, PO-C had the percentile with the highest moisture content decrease of 58.74%. In the case of testing the surface tension value, it was found that traditional mineral oil had the highest value (48.46 m/Nm) when compared to palm oil. On the other hand, the acidity in traditional mineral oil is the lowest (0.03 mg KOH/g) compared to all palm oils. Results from studies demonstrate the possibility of using natural processed crude palm oil, or PO-C, as a replacement for traditional mineral oil. This is consistent with the results of electrical properties that show PO-C is higher than other types of palm oil and includes traditional mineral oil.

The purpose of this study was to investigate the electrical properties of pressboard impregnated with mineral oil-based nanomaterial. The nanomaterial focused on in this study was magnetite (Fe₃O₄) at ratios of 0.01, 0.03, and 0.05 by mineral oil volume. The electrical tests were performed on the AC breakdown strengths and positive-negative lightning impulse breakdown strengths on impregnated pressboard were carried out in compliance with IEC 60641 and IEC 60243, respectively. Scanning electron microscopy (SEM) and X-ray Diffraction (X-RD) were used to study the micro surface and show that Fe₃O₄ nanoparticles of nanoscale size were adhered to the pressboard surface and exist in an amorphous state. The results found that the AC breakdown strengths of pressboard impregnated with mineral oil-based Fe₃O₄ nanofluids at 0.03 wt were increased the most. Moreover, the lightning impulse breakdown strengths of pressboard impregnated with mineral oil-based Fe₃O₄ nanofluids at 0.03 wt were increased the most in both positive and negative polarities. The results, thus, showed promising directions for applications of Fe₃O₄ nanomaterials to improve the electrical properties of pressboard.

The present study aimed to develop the electrical performance of outdoor insulators using a nano-TiO₂ coating for railway electrification systems. The prototype design of porcelain insulators with normal coatings and using a nano-TiO₂ coating is based on IEC 60815-1. The first test was performed to measure the low-frequency flashover AC voltage under both dry and wet conditions. In addition, the other test was conducted to measure the lightning impulse critical-flashover voltage at positive and negative polarity under dry-normal and wet-contaminated conditions. X-ray diffraction (X-RD) and Scanning electron microscopy (SEM) were used to examine the micro surface and show that the nano-TiO₂ coating was adhered to the surface of the outdoor porcelain insulator and exists in an amorphous state. Additionally, it was observed and discovered that scattered nano-TiO₂ strengthens the glassy matrix and creates a sturdy barrier that causes flashover voltage to be reduced under conditions of high dielectric strength. Nanostructured ceramic formulations outperform ordinary porcelain in terms of breakdown voltage strength, particularly for the insulators’ low-frequency flashover performances under dry and wet test conditions. However, a significant change in the lightning impulse critical-flashover voltage characteristics is observed and is not much better when adding the nano-TiO₂ coating to the porcelain insulators.

The objective of this research was to study the use of rice bran oil mixed with nanoparticles as liquid insulation in transformers by enhancing the efficiency of properties for rice bran oil. To clarify, 3 types of nanoparticles were mixed, i.e., magnetite (Fe₃O₄), titanium dioxide (TiO₂), and aluminium oxide (Al₂O₃). All of these were mixed in rice bran oil at a 0.01 wt% concentration of rice bran oil volume to improve its electrical, chemical, and physical properties. According to the electrical test, it was found that rice bran oil mixed with 0.01 wt% Fe₃O₄ nanoparticles of rice bran oil volume contained the highest AC breakdown voltage, with the best lightning impulse breakdown voltage at anode and cathode. As for power loss in the insulators, it was found that Fe₃O₄, TiO₂, and Al₂O₃ nanoparticles added into rice bran oil could reduce power loss factors in rice bran oil, indicating better electrical efficiency. Besides, rice bran oil mixed with these nanoparticles also contained close relative permittivity to regular rice bran oil and transformer oil. In the test of electrical resistance, it was discovered that transformer oil and rice bran oil mixed with nanoparticles had lower resistance than regular rice bran oil. This meant that the mixture was better at insulating. The chemical property test showed that rice bran oil mixed with nanoparticles had more water than mineral oil and more acidity than transformer oil. This suggests that rice bran oil might still have some issues with long-term use if the right amount of water and acidity are not controlled. The physical property test showed that the surface tension of rice bran oil mixed with all three types of nanoparticles was higher than that of regular transformer oil. For the dynamic light scattering test (DLS) to observe dispersity of nanoparticles in oil, it was found that rice bran oil mixed with Fe₃O₄ nanoparticles contained a better polydispersity index (PDI) than rice bran oil mixed with TiO₂ and Al₂O₃ nanoparticles, indicating that Fe₃O₄ nanoparticles added could encourage efficient dispersity. This research revealed the efficiency of nanoparticles to improve properties of rice bran oil, particularly when mixed with 0.01 wt.% Fe₃O₄ nanoparticles that brought better electrical properties of rice bran oil in terms of breakdown voltage and lower power loss while enhancing its insulatability.

This study aims to evaluate the potential for the use of refined, bleached, and deodorised palm oil (RBDPO) as a sustainable insulating fluid for power transformers by enhancing its properties through the addition of nanoparticles. Specifically, Fe₃O₄, TiO₂, and Al₂O₃ nanoparticles were each added to RBDPO at a concentration of 0.01 wt% in order to assess their impacts on dielectric and physical characteristics. A series of experiments were conducted, including lightning impulse breakdown voltage (BDV) testing, Weibull statistical analysis, dissipation factors, resistivity, and dynamic light scattering (DLS) to evaluate particle dispersion. The results show that TiO₂ nanoparticles provided the greatest enhancement. Compared to unmodified RBDPO, the BDV at 63.2% probability increased by 32.80% (positive polarity) and 32.01% (negative polarity). Furthermore, RBDPO with TiO₂ exhibited the lowest dielectric loss (tan δ = 1.996%), the highest resistivity (9.84 × 10⁹ Ω·m), and the smallest particle size with the best dispersion (PDI = 0.077). In conclusion, TiO₂ nanoparticles at 0.01 wt% significantly improved the electrical and physical properties of palm oil, confirming its suitability as an alternative liquid dielectric for high-voltage transformer applications.