Lightning breakdown voltages of refined bleached and deodorised palm oil under needle-plane configuration

In recent years, vegetable oil such as Palm Oil (PO) has been identified as a potential alternative dielectric insulating fluid for transformers. It is biodegradable, non-toxic and has high flash and fire points. In this paper, a study on the positive lightning impulse breakdown voltages of PO under non-uniform field is carried out. The testing was carried out using needle-plane electrodes configuration at gap distances of 25 mm and 50 mm. Rising voltage, 1 and 3 shots per step testing methods were used and 3 types of Refined Bleach and Deodorized Palm Oil (RBDPO) and Mineral Oil (MO) were examined. It was found there is no significant effect on the breakdown voltages of all samples. The breakdown voltages of all RBDPO at 50% probability are comparable with MO. At 1% probability and gap distance of 50 mm, the breakdown voltages of all RBDPO are lower than MO

Development of palm - based neopentyl glycol diester as dielectric fluid and its thermal aging performance

The potential of palm-based neopentyl glycol diester as dielectric insulating fluid was investigated. The details of the transesterification of high oleic palm oil methyl ester (POME) with neopentyl glycol (NPG) with the final product yield of more than 90 wt% of NPG diester were discussed. The thermal aging performance of NPG diester was compared with conventional mineral insulating oil at 90, 110 and 130 °C. This paper focused mainly in the effects of aging to chemical, physical and electrical properties of NPG diester. Apart from being fully biodegradable and non-toxic, the synthesized diesters exhibited high flashpoint and the breakdown voltage was comparable to mineral oil. The result indicated that throughout the aging period, NPG diester exhibited lower acid value than mineral oil and no significant change in viscosity was observed. The study on mechanical properties of insulating paper aged in NPG diester shows higher tensile strength than paper aged in mineral oil. The synthesized esters have shown great potential to be used as transformer oil

Investigation on the effect of moisture on AC breakdown voltage of refined, bleached, and deodorized palm oil

The effect of moisture on the AC breakdown voltage of palm oil was studied in this paper. The type of palm oil used in this study was Refined, Bleached and Deodorized Palm Oil (RBDPO) olein. RBDPO with different moisture contents were prepared by oven drying method. The AC breakdown voltage measurement was carried out based on ASTM D1816 at a gap distance of 1 mm. The AC breakdown voltage data were analyzed statistically by normal, lognormal and Weibull Cumulative Distribution Function (CDF). It is found that the AC breakdown voltage of RDBPO decreases almost exponentially as the moisture content increases. Weibull CDF can represent most of the AC breakdown voltage data of RBDPO at different moisture content

Effects of different types of surfactants on AC breakdown voltage of refined, bleached and deodorized palm oil based CuO nanofluids

In this paper, the effects of different types of surfactants on AC breakdown voltage of Refined, Bleached and Deodorized Palm Oil (RBDPO) olein in the presence of Copper (II) Oxide (CuO) nanoparticle were investigated. The AC breakdown voltage measurement was carried out based on ASTM D 1816 at gap distances of 1 mm. Sodium Dodecyl Sulfate (SDS) as anionic surfactant, oleic acid (OA) as non-ionic surfactant and Cetyl Trimethyl Ammonium Bromide (CTAB) as cationic surfactants were used to investigate the influence of different concentrations surfactants on the AC breakdown performance of RBDPO. The concentrations were varied at 25%, 40%, 50%, 60% and 75% of volume percentage based concentration of 0.05% CuO. The results showed an enhancement of AC breakdown voltage under presence of SDS, OA and CTAB until 50% volume of concentration

Influence of electrode geometry on the lightning impulse breakdown voltage of palm oil

This paper presents a study of lightning impulse breakdown voltage of palm oil under needle/plane and needle/sphere electrode configurations. All tests were carried out at gap distance of 25 mm under both positive and negative polarities. Two types of palm oil and mineral oil were used in this study. The results show that the different electrode geometry has significant impact on the lightning impulse breakdown voltage. It was found that needle/plane geometry has lower breakdown voltage than needle/sphere. The voltage polarity also showed some influence on the lightning breakdown voltage for all fluid samples. Comparing both positive and negative polarities, the percentage of difference between all samples is much higher under needle/plane electrode configuration which can be up to 43%. The positive mean lightning breakdown voltage of palm oil is comparable with the mineral oil

Pre-breakdown streamer propagation and breakdown characteristics of refined bleached and deodorized palm oil under lightning impulse voltage

This paper presents the investigation on the breakdown characteristics and pre-breakdown streamer propagation of Palm Oil (PO) impregnated aged pressboard under positive lightning impulse voltages. The experimental work was carried out under a non-uniform field with needle-plane electrodes configuration. The streamer stopping length and breakdown voltage of 2 types of refined, bleached, and deodorized palm oil were examined in the presence of new and aged pressboards. The pressboard was placed in parallel to the needle-plane electrode at a gap distance of 50 mm. The lightning breakdown voltage was applied to the samples based on 1 shot per step rising voltage method under positive polarity as per IEC 60897. The presence of impregnated pressboard in both PO slightly increases the 50% positive lightning breakdown voltages. PO impregnated pressboards have lower 50% positive lightning breakdown voltages than MO. After subjected to ageing, the positive lightning breakdown voltages for PO and MO impregnated pressboards decrease. In the presence of aged pressboard, the streamers in PO generally propagate further than MO at the same voltage level

Investigation on the dielectric, physical and chemical properties of palm oil and coconut oil under open thermal ageing condition

In this paper, a study is carried out to investigate the dielectric, physical and chemical properties of Palm Oil (PO) and Coconut Oil (CO) under open thermal ageing condition. The type of PO used in this study is Refined Bleached and Deodorized Palm Oil (RBDPO) Olein. The ageing experiment was carried out at 85 °C and 115 °C for 1, 3, 5, 7 and 14 days. Several parameters were measured such as AC breakdown voltage, dielectric dissipation factor, relative permittivity, resistivity, viscosity, moisture and acidity throughout the ageing duration. Based on the study, it is found that there are no significant changes on the AC breakdown voltages and relative permittivities for both RBDPO and CO. At ageing temperature of 115°C, there are clear reduction trends of dielectric dissipation factor for CO and resistivities for most of RBDPO. On the other hand, no clear trends are observed for viscosities, moisture and acidities of RBDPO and CO throughout the ageing duration

A study on the dielectric properties of palm oil and coconut oil

One of the important parameter for insulating fluid is the dielectric properties. With the introduction of vegetable oil as possible alternative fluid for transformers application, it is essential to ensure this type of oil could meet the dielectric properties requirement. In this paper, a study is carried out to investigate the dielectric properties of Palm Oil (PO) and Coconut Oil (CO). The type of PO used in this study is Refined, Bleached and Deodorized Palm Oil (RBDPO) Olein. Several parameters such as AC breakdown voltage, dielectric dissipation factor, relative permittivity and resistivity are examined for both as-received and dried samples. It was found that there are differences on the dielectric dissipation factor and resistivity between RBDPO and CO and the dielectric properties performances of all samples are improved after subjected to the drying procedure

Investigation on the lightning breakdown voltage of palm oil and coconut oil under non-uniform field

The increasing interests on the Palm Oil (PO) and Coconut Oil (CO) as a potential alternative for dielectric insulating fluid in transformers encourage a number of researches on different aspects of these oils. Among the common areas under study is the lightning breakdown voltage. In this paper, the lightning breakdown voltage of PO and CO is examined. The type of PO used in this study is Refined, Bleached and Deodorized Palm Oil (RBDPO) Olein. The testing was carried out under non-uniform electric field using needle-sphere electrodes configuration. The influence of the testing methods, rising-voltage and up-and-down on the breakdown voltages are investigated for both types of oils. It was found that the lightning breakdown voltage performance for some of the RBDPO is comparable to Mineral Oil (MO)

A study on the AC breakdown voltages of as-received palm oil and coconut oil under presence of TiO2

This paper presents a study on the AC breakdown voltages of Palm Oil (PO) and Coconut Oil (CO) with presence of TiO2. The type of PO used in this study is Refined, Bleached and Deodorized Palm Oil (RBDPO). TiO2 was added into RBDPO and CO at volume concentration of nanoparticles ranging from 0.001% to 0.05% In total, 50 measurements of AC breakdown voltages were recorded and analyzed by Weibull and normal distributions. Based on the test results and statistical analyses, it was found that the TiO2 could improve the AC breakdown voltages of RDBPO and CO