On the physical significance and di-electric response of Castor oil processed in Nigeria as transformer insulating fluid

International Journal of Research and Innovation in Applied Science (IJRIAS) |Volume VIII, Issue III, March 2023|ISSN 2454-6194

On the physical significance and di-electric response of Castor oil processed in Nigeria as transformer insulating fluid

Oyinkanola L.O.A, Aremu O.A, Fajemiroye J. A, Makinde .S.O
Physics Department, The Polytechnic, Ibadan. Nigeria
Received: 24 October 2022; Accepted: 04 November 2022; Published: 07 April 2023

Abstract: – In view of castor oil as non-toxicity and good di-electric properties which can be used as dielectric fluid inside transformer. Castor oil, a polar liquid dielectric of vegetables origin is studied. This paper presents a description of frequency domain dielectric response technique with the physical and mathematics background.
The measurements were made using the L-C-R meter connected by co-axial cable and signal generator. Relative permittivity of castor oil was determined at frequency ranging from 25Hz to 150 KHz and temperature ranging from 270C to 1000C.
The data obtained have been statistically analysed. It was observed that the real part of the relative complex permittivity was frequency independent. It also shows that there is a slight deviation between complex permeability of the oil sample and temperature increases compared with the result of typical transformer oil.

I. Introduction

Transformer that are normally use in electric domain are of a homing type and the distribution transformer selection, whether for residential, commercial, industrial, or utility application, has long-term ramifications. Transformer can have live span of 15, 30 and even 50 years or more, depending on their design, loading, application, protection, and maintenance. It is important to evaluate all the transformer attributes that effect the purchase decision. (Paranjpe etal., 1935). Liquid-filled transformer are often not considered as an option for indoor installations due to historical issues of fire safety, environment concerns, and special containment. Because of these perceptions, vacuum pressure impregnates (VPI) dry-type and cast-resin transformer have often replace liquid-filled transformers for indoor and adjustment to building installations (Dervos et al., 2005). With this trend, significant advantages like superior life, efficiency, sound level, overload capacity, contamination resistance, and online diagnostics which are characteristics of liquid transformers have been lost Safety and environmental issues have been improved due to changing in the transformer fluids and listing requirements, so that the benefits of liquid-filled transformers can be retained for indoor and adjust to building installation (Cigke, 2005).
Since the 1970s, the public has been sensitized to the polychlorinated biphenyl (PCB) based transformer oils. In 1976, the Toxic Substance Control Act targeted PCB. The beginning of further production and commercialization of PCBs, and increasingly restrictive Federal and state regulations, led to the introduction of other fire-resistant transformer types. While most PBC oil filled transformers have been replace with PCB free mineral oil, fire resistance hydrocarbon fluids, or silicone oil, the replacement fluid have still not been environmentally preferred (Nozaki, 2005). Vegetable oils are increasingly used in the electrical industry as an insulator since they are non-toxic to the environment, biodegradable if spilled and have high flash and fire points. Vegetable oils. However, have to be traded-off their benefits with biodegradable characteristics. Thus, they are generally used in system with no exposure to the atmospheric oxygen. ( Boonchoo, 2007 )

Highly insulation oil used to suppress partial discharge, increase the dielectric strength and increase the effective permittivity (dielectric constant) of the capacitor die-electric (Nozaki, 2005) Oil-filled film capacitors used at high voltage, such as ceramic capacitors (Rawlins, 1985).
Vegetable-oil based insulating fluid has not been accepted because of their high pour point and inferior resistance to oxidation relative to mineral oil they. We are also believed to be more expensive compared with the mineral oil has been in use for electrical insulation in transformers and other oil-filled electric equipment. With recent frequent increase in the prices of petroleum and uncertainly concerning petroleum products availability, accelerated research and development are on around Nigeria in search for alternative to petroleum products. Part of this is a renewed interest in the use Groundnut oil, Cotton seed oil soyabean oil and castor oil as industrial insulating fluid since this is yielding positive result in some other part of the world, but their viscosities are lower than the castor oil ( Schneuwly et al., 1990). Also, castor oil has hydroxide content of about 5%, is an important polysaccharide reagent. The chemical composition of this unsaturated oil which has a high relative permittivity between 4.2 and 4.5. Castor oil has therefore found wide application as impregnating agent in power capacitors such as transformers (Boonchoo, 2007)

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