Potential application of palm oil products as electrical insulating medium in oil‐immersed transformers

Abstract

The physico-chemical and electrical insulating properties of certain palm oil products, including triglyceride oils, fatty acids, fatty esters, and glycerol were evaluated for use in oil-immersed transformers. The studied triglyceride oils have excellent kinematic viscosity values: 30.25-40.49 mm 2 s À1 at 40 C, 6.46-8.34 mm 2 s À1 at 100 C; flash point: 278-320 C; moisture content: 16-175 mg kg À1 and dielectrical breakdown voltage: 29.1-40.9 kV. Fatty acids and fatty esters have relatively lower kinematic viscosity and flash point values than triglyceride oils. The type of hydrocarbon chain, hydrocarbon chain length and molecular size were shown to have substantial effects on the physico-chemical and electrical properties of the studied oils. The drying process imposed on refined-bleached-deodorized palm olein (RBD POo) has reduced the moisture from 400 mg kg À1 to 100 mg kg À1 and improved the dielectrical strength from 31.1 kV to 76.8 kV. Blending of RBD POo with fatty acids or fatty esters has improved the kinematic viscosity of RBD POo and offers even higher flash and fire points than mineral oil. This study showed that palm oil and palm oil products have strong potential to serve as coolants and may be safer for use in oil-filled transformers as compared to mineral oil.

A Review on Palm Oil-Based Nanofluids as a Future Resource for Green Transformer Insulation System

“…5 and Table II depict various ACBDV results of PO by various researchers that used 2.5 mm gap distances of electrodes as a benchmark. Mohd N. K. et al [73] compared the ACBDV of RBDPO olein, RBDPKO, and CPO, where it was figured out that CP obtained the highest ACBDV value, followed by RBDPO olein and RBDPKO. However, experimental findings demonstrated that RBDPO olein, after being blended with oleic acid (OA), produces the highest ACBDV compared to other PO samples.…”

“…However, only a few studies have found that the results of fire points exceed the limit. Senthilkum et al [180] and Aditama et al [181] studied the flash point of RBDPO and obtained high flash point values of 320 o C and 424 o C. Mohd et al [73] compared the flash point and fire points of several types of RBDPO with and without additives. It was discovered that RBDPO without any additives has a significant flash point and fire points that also exceed 300 o C temperature.…”

“…It contradicts the theory, which could be due to the low-fat content of the PO examined by the author. In terms of kinematic viscosity at 100°C, all the oil samples tested by the researchers were below the ASTM recommendation value.In the year 2021, Mohd et al[73] measured the kinematic viscosity of different types of PO at 40 o C and 100 o C. In comparison to the acceptable limit specified in ASTM D6871, all the studied PO have lower values ranging from 16.68 mm 2 s -1 (RBDPO with methyl laurate) to 40.49 mm 2 s -1…”

Assessing Electrical and Physicochemical Performance of Chemically Modified Palm Oil as an Alternative Transformer Liquid

“…The conversion of triglycerides to methyl ester appeared to be the primary cause of the viscosity reduction. Low viscosity transformer oils are preferred because they promote heat transfer and circulation (Mohd et al, 2021;Walvekar et al, 2022). NPs employed increased, the water content of their NF decreased.…”