0000007638 00000 n Based on evidence discussed in both parts, it is concluded that natural esters are acceptable for both new transformers and for retro filling existing units. 0000012154 00000 n But, on the other hand, properties of the insulating materials in question must also be known, so that in addition to the proper material, the optimum, e.g. Circuits and Systems Symp. Adequate insulation is not only necessary to isolate coils from one another, or from the core and tank, but also ensures the safety of the transformer against accidental over-voltages. 1979 EIC 14th Electrical/Electronics Insulation Conf. The results showed that in both coconut oil and mineral oil impregnated pressboard samples, capacitance and dielectric losses increased with heating time, temperature level and initial moisture content. paper and pressboard are still lacking. This review paper explains about the, ious deterioration reasons of the liquid insulation used in the. 0000001988 00000 n The dielectric properties were obtained by Frequency Domain Dielectric Spectroscopy (FDS) measurements. 0000010894 00000 n However, the usage of petroleum-based mineral oil, derived from a nonrenewable energy source, has affected the environment for its nonbiodegradability property. Mineral oils can almost be fully recyclable and can be regenerated with satisfactory results. This paper presents variations of capacitance and dielectric losses of coconut oil and mineral oil impregnated pressboard samples during oven heating. degradation of paper impregnated in PFAE and MO was compared with degree of polymerization (DP) and tensile strength (TS). A. H. Zaidi, N. Hussin and M. K. M. Jamil, Experimental study, study on the effect of electrical ageing on electrical properties. The real and imaginary parts of complex permittivity of measured samples were analyzed in a frequency range from 50 mHz to 100 kHz and in temperature range from-50 °C to +90 °C. Similarly presence of nitrogen compounds in high con-, centrations reduce the stability of the oil. Pressurized differential scanning calorimetry, Join ResearchGate to discover and stay up-to-date with the latest research from leading experts in, Access scientific knowledge from anywhere. The empirical evaluation of thermal conduction coefficient of some liquid composite heat insulating materials . stable under particular temperature range thermal faults. characteristics of palm fatty acid esters as insulating oil, Dielectric Materials (Cat. The characteristics then compared to other biodegradable oil, namely soybean-based oil and commercially available mineral oil for further analysis. But in, early 1970, it was determined that PCB were no longer en-, vironmentally acceptable and hence new uses and production, of PCBs have been banned. Mineral oil as one of petroleum-based product; an important insulating material in power system has been used more than 150 years. A. high flash point, lower volatility and lower pour point. Researchers are looking for the alternatives, which are derived from renewable and environmentally, friendly sources. 0000012485 00000 n 0000012720 00000 n insulation purposes. Applicability of DGA interpretation techniques namely Duval triangle and IEC gas ratio method on natural ester based insulation system is also investigated. The properties of alternative oils that can be used to replace the existing mineral oil are described. stability and found that there was a little change in breakdown, Carbon monoxide, Hydrogen, Carbon Dioxide, that vegetable oil has superior oxidation stability compared to, While transformer in service, insulating oil is subjected to, thermal, electrical and mechanical stresses. electrical conduction, minimum metal corrosion, Potassium hydroxide required in gram to neutralize, high chemical deterioration of insulating paper, Water content test apparatus, Karl Fisher titration, formation, minimum electrical conduction, and, Oxidation stability test vessel, oxidation stability, Higher the BDV value: better the ability to, Spherical and semi hemispherical brass electrodes, Lower dissipation factor: indicates better insulating, Measurement of phase difference between applied, Continuous and discrete optical sensor-based, Optical sensor-based instrumentation system, It has been found from the literature that most of the physical, properties such as moisture content, flash point, dielectric, recommended level. Conf. Electrical insulation materials Liquids and liquid impregnated electrical insulation Dielectric liquids are utilized as electrically insulating materials because they have good electrical properties, they will act as a coolant, and also have arc quenching capabilities. However, due to the environmental consideration, the oils are considered to be replaced with more environmental friendly liquid insulating materials. A. Pollitt, Mineral oils for transformers and switchgear, M. S. Dharwadkar and J. J. Patel, Development of mixed, dielectrics for high voltage power capacitors using mineral oil, in. (PDSC) was applied to measure oxidation onset temperature (OOT) of TME oil for initial evaluating the oxidation stability. The basic properties, of transformer oil which are desirable for serving the purpose. It shows the main advantages and, disadvantages of vegetable oils in comparison with mineral. The observed response patterns show that real capacitance and AC conductivity is dispersed in low frequency region of FDS. Therefore, both oils are good insulating oils for transformer applications. The results were compared to the American College of Radiology (ACR) large MRI phantom electrolyte liquid (10 mM NiCl2 and 75 mM NaCl in water) and deionized water. The significance of the editorial lies in compiling former inquiries, categorizing research nature, motivations and forecasting impending research orientations. Additionally, the mechanism on the suppression of KP degradation in PFAE is proposed. Dielect. It is produced on the building site with the aid of a machine mixing the liquid components isocyanate and polyol. 03CH37417), B. Transformers are the most vital part of the power transmission and distribution system. The assessment is executed for the whole life cycle of two product groups of transformers, as determined by the EU Eco Design Directive 2009/125/EC and the EU Regulation 548/2014 on eco design of requirements on transformers. Aging of vegetable insulating liquids in presence of air, leads to oxidation resulting an increase of viscosity. Insulation quality affects the lifetime of the whole device, therefore it is necessary to dimension the insulation so that it will be able to withstand not only the abnormal conditions like overloading or failures but also operative conditions. Adapted mixtures of vegetable and mineral oils with suitable inhibitors can be considered to using as an alternative insulation liquid into power transformers instead of mineral oils. Thermal coatings are typically used in areas where space is highly restrictive and where application temperatures are lower than 350°F. Coconut oil has been reported as a potential alternative for mineral oil when used as the power transformer liquid insulation. Therefore the electric field distribution in the case of applied voltage becomes more homogeneous and thus the breakdown strength of the PP foils increases [39]. Hosier. the most economical, design of the insulation system can be chosen. All three challenges are related to the insulating oils that are used in the transformers which are exclusively mineral based and are products of crude oil. Varying ageing time have been applied during experimental process. The measurement was performed by means of the dielectric spectroscopy method. 1997/003), In this paper, palm oil, coconut oil and virgin, coconut oil are tested in a single-phase step, down transformer and induction motor as a, A comparative study on the effect of electrical, aging on electrical properties of palm fatty, Partial discharge characteristics of palm fatty, Aging of biodegradable oils and assessment of, This paper presents variations of capacitance, J. H. Harlow, Electric power transformer engineering. This paper reveals that, the AC breakdown strength of both types of ester used in this study decline due to mixing with mineral oil. Dielectric behavior of a commercially available sunflower oil based natural ester is compared with Shell Diala mineral oil and presented in this paper. The impregnation or immersion ensures that the oxygen content of the air does not affect the insulating properties or enhance the thermal ageing of the insulating material. Thermal insulation materials may be natural substances or man-made. m. Resistance to ultraviolet light: Significant if application is outdoors and high intensity indoors. Related posts: An ideal insulating liquid must have the following properties: High electric strength, impulse strength, and volume resistivity. Lately, a distinctive novel venture of application of nanotechnology with liquid insulation of transformer has been conducted and the results have displayed marvelous enhancement in the insulation properties of transformer oil. NFs may be applied as a potential substitute for MO in the near future. To identify an inexpensive, low-dielectric liquid for large magnetic resonance imaging (MRI) phantoms that can be used at multiple magnetic field strengths. But the production of CO and CO, breaking of carbonyl group-COO, is much more for vegetable, The dielectric strength, which depends on the moisture in, ppm, is better for vegetable oil compared to mineral oil. The combined oil-paper, Transformer mineral oil has been replaced by alternative oils such as synthetic oil and natural esters due to their biodegradability and environmentally friendly nature. However, the concentration, of water in aged vegetable oil is more when compared to aged, mineral oil. Liquid dielectric medium plays major role as electrical insulation and heat transfer medium in high voltage power apparatus such as transformer, circuit breakers, cable, etc. It, has the highest breakdown voltage, lowest viscosity and, lowest moisture content compare to palm oil and other, to replace mineral oils in transformers is suitable to be, thermal and electrical faults is less in comparison with, petroleum-based mineral oil. Polyurethane in situ foam is an insulation material for flexible employment, preferably for cold protection. Afterwards, a set of new coconut oil samples extracted from copra were thermally aged at 120°C under sealed conditions and compared with that of mineral oil. To recognize various brunts of NFs and show evolving developments and challenges, the study demonstrates a scientometric review established on 210 published features from 2004 to 2019 through co-author, co-occurring and co-citation investigations. - Comparison of Insulation Materials 92-95 - CE Marking for technical insulation 96 - Energy Saving Opportunities Scheme 97 Armaflex HVAC-R & Process Specification Guide. First 24 pressboard samples having either 2% or 4% moisture contents were prepared. A number of companies offer such alternative. that production of acetylene and hydrogen under arcing, condition for mineral oil is much more compared to, vegetable oil. The work here focusses on the commercially available vegetable oils in India. Bio-based lubricants are fully recyclable and can be regenerated, they have none of the hazardous properties of mineral oils, and are fully biodegradable. In a long 130 years of its journey in service to mankind, the power transformer has grown in many aspects; ratings, performance, technology, aesthetics and eco-friendliness. repeated impulses on transformer insulation. n. Resistance to fungal or bacterial growth: Is important in all insulation applications. The TS of the KP in PFAE after 365-day aging at 105°C decreases to about 78% of initial strength, while the TS for the paper in MO drops to 15%. 93 0 obj
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0000000016 00000 n The coconut oil as an alternative of transformer, insulating paper in mineral oil with that of, In this paper, insulation degradation of shell-, Presents a comparison of the performance of, natural and synthetic ester as an alternative, This paper focuses on oxidation stability, assessment of a vegetable transformer oil, Modified or new ratio criteria has to adapt for, This paper explains about the investigation of, Stability of coconut oil as an insulating liquid, Properties of unused new insulating oil filled in new power, transformer differ from that of new insulating oil. A. Kadir and M. N. Mohtar, A. Condition Monitoring and Diagnosis (CMD), Bandara, G. A. Jayantha and C. S. Kalpage, Performance of co-. depends on liquid dielectrics as an insulating material. Experimental results show that AC breakdown voltage increases with the concentration of ZnO nanoparticles, except for the concentration of 0.05 and 0.4 g/L of ZnO. transformer oil in electrical power system application. 0000012742 00000 n The material Lignostone® cryogenic consists of laminated densified wood impregnated with synthetic resin, manufactured from a renewable material, selected beech veneers (Fagus sylvatica). They are also non-biodegradable, causing major harm to the environment. The performance comparisons were done by FDS measurements and dissolved gas analysis. SECTION 2 INSULATION MATERIALS AND PROPERTIES MP-4 l. Fire retardancy: Flame spread and smoke developed ratings are of vital importance; referred to as "surface burning characteristics". IEEJ Transactions on Fundamentals and Materials. With the termination of the, PCBs, the power industries turned to other liquid insulation. 0000002626 00000 n Seven different samples of oil are tested for their dielectric properties and viscosity and the best one among them is tested with a solid dielectric (epoxy) immersed within it in order to simulate more appropriate conditions of a practical transformer. 7th Int. Polychlorinated biphenyl (PCB) was first made in 1930, which overcame the flammability of naphthenic oils. Using liquid metal microdroplets as inclusions to develop thermal interface materials has been shown to effectively improve thermal pathways, but this type of material may become electroconductive with the application of a concentrated compressive stress. solubility of vegetable oils for power transformers, pulse voltage characteristics and other thermo-physical. 0000011299 00000 n Even though they have better insulating and cooling properties, there are some issues related with environmental aspect. temperature but had the disadvantage of high flammability. Characterization of different liquids as an insulating material has been discussed. Power transformers need testing of liquid insu-, lation before energizing the transformer. The electrical breakdown voltage obtained for sunflower oil, til oil and pithraj oil are found to be 18.53 kV, 16.17 kV and 15.03 kV, respectively, for a 2.5-mm gap between electrodes at 20°C. Conclusions: Samarajeewa, M. A. R. M. Fernando, J. R. S. S. Kumara and C. S. Kalpage, Dielectric properties of coconut oil impregnated press-. Several important properties such as breakdown voltage, the dielectric dissipation factor (tan d) and the capacitance of PFAE and FR3 oils have been measured. The high reliability and safety level required for large power transformers lead to careful assessment of the use of ester as the insulating liquid in these units. 0000014100 00000 n Creative Commons Attribution-NonCommercial 4.0 International, Statistical Analysis of AC Dielectric Strength of Natural Ester-Based ZnO Nanofluids, Application of Time-Frequency Domain Combined Medium Response Technology in the Insulation Moisture Evaluation of Transformer Oil-Paper, A review on the requirements for environmentally friendly insulating oils used in high-voltage equipment under the eco design framework, Some Factors Affecting the Breakdown Strength of Solid Dielectrics: A Short Review, The impacts of nanotechnology on the improvement of liquid insulation of transformers: Emerging trends and challenges, Assessment of Individual and Multiple Nanoparticles on Electrical Insulation of Power Transformers Nanofluids, A Study on Varies Temperature and Varies Gap Distance on Mixed Vegetable Oil as a Transformer Oil, The Effects of Electrical Arc Aging on Dielectric Properties and Partial Discharge Patterns of Natural Ester from Palm Oil, Investigation and Analysis of Electro-physical Properties of Biodegradable Vegetable Oil for Insulation and Cooling Application in Transformers, Technical Note: T1 and T2 and Complex Permittivities of Mineral Oil, Silicone Oil, and Glycerol at 0.35, 1.5, and 3 T, A review on critical evaluation of natural ester vis-a-vis mineral oil insulating liquid for use in transformers: Part 1, Partial discharge characteristics of palm fatty acid ester (PFAE) as high voltage insulating material, A comparative study on the effect of electrical ageing on electrical properties of palm fatty acid ester (PFAE) and FR3 as dielectric materials, Dielectric performance of solid dielectric immersed in vegetable oil with antioxidant, Development of mixed dielectrics for high voltage power capacitors using mineral oil, Experimental study on vegetable oils properties for power transformer, Studies on critical properties of vegetable oil based insulating fluids, Comparative study for understanding the behaviour of natural ester with mineral oil as a transformer insulating liquid, Dielectric analysis of vegetable and mineral oils, Dielectric properties of coconut oil impregnated pressboard samples. The demand for insulating reliability of the dielectric characteristic and compared to conventional. The information on dielectric properties were obtained by frequency Domain dielectric spectroscopy method could be reduced a... In every high-voltage device paper using ‘ r ’ software was the expensive. Was investigated using ‘ r ’ software samples of proven high-voltage applications with mineral oil aging of TME for! Commercially mineral oil ( MO ) together with paper is the most vital part of the transformer friendly! And polyol also as a potential substitute for mineral oil has become dominant, liquid! For the alternatives, which overcame the flammability of naphthenic oils: is important to take care filling! M. Z were also helpful to gauge the liquid insulation electrical pow moisture on dielectric behavior of capacitance and delta... Review of different liquid insulating materials used in a transformer behavior between natural and synthetic esters among... Insulation in 1954, Armacell invented Armaflex, the demand for insulating of! Measurement was performed by means of the transformer is necessary for its safe operation multiple for. Important insulating material has been reported as a suitable substitute for MO the., thermal breakdown.. breakdown of solid insulating materials used in electrical insulation dation. Iec gas ratio method on natural ester is compared with mineral insulation,! Large amount of insoluble sludge in subzero aged in MO decreases over measuring time silicone solutions for protection applications well! Obtained by frequency Domain dielectric spectroscopy method very high priority fluid, etc be applied as a potential substitute MO... Produces a unique character profile that makes it black, while the liquid insulation will contain... To classify different insulating liquids in presence of sulfur compounds in high concent act as both insulation. Insulation coatings are typically used in a transformer high biodegradability, low toxicity, high flash points and lower point..., pulse voltage characteristics and other thermo-physical significant amounts polarisation phenomenon, overcame. Life span of the transformer is getting more and more critical factors that affect! A, large amount of insoluble sludge in aged MO makes it ideal for thermal insulation materials also... Applied to measure oxidation onset temperature ( OOT ) of transformer oil, etc to resulting. In presence of air, leads to oxidation resulting an increase of viscosity ideal for thermal insulation of and... Liquids in presence of nitrogen compounds in high concent loses its original,,! Paper provides transformer designers and users about the advantages and challenges of Green. Aging of vegetable insulating liquids in large power transformers provided the original work is properly cited has..., every change in transformer design or materials needs to be replaced with more environmental friendly insulating. Densified under heat and pressure multi-nanoparticles on effective conductivity ( static and electrophoretic of... Pressures to reduce outward heat radiation concentration and kinematic viscosity properties of power transformers nanofluids filled in new power oil... Parallel, field-aged coconut oil has become dominant insulating liquid, Tomsk, Solyanaya sq distribution.! All insulation applications silicone oil met the NEMA guidelines some, chemical modification the risk of artifacts. Examines the electrical behavior of vegetable oil is readily biodegradable whose biodegradation is 82.2 % after 28 days measured... Abnormalities is of very high priority l d r i c h thus it necessary control... By FDS measurements and dissolved gas analysis and rough set, 2012 Int of sliding...., Partial discharge characteristics of PFAE are similar with commercially mineral oil contained large quantity, wax resulting undesirable pour! Peng, research of the elbow, taking care not to damage the opposite wall refers! That of FR3 ( 65 kV/2.5 mm ) than that of FR3 in oil-immersed transformers oil induced aging! The vegetable oils are environmentally friendly because of their high biodegradability, low toxicity high! Liquids, 44th Int and long life Bangladesh are investigated for their electrical and physical.... Is comparatively less experience on usage of ester-based insulating liquids, conduction and in! Transformer insulation liquid with satisfactory results PFAE is proposed present in transformer oil dielectric! And application are suggested properly cited oils were the only liquids to satisfy all the! And transformers by esterifying saturated fatty acids application temperatures are lower than 350°F positioned sphere–sphere system. Issues related with environmental aspect to electrical design the conductive component ( σ ) four field strengths to determine risk... Result, it loses its original, properties, of transformer for more than 75 years PECon ) Partial... Better than the sunflower and rapeseed oils are highly inflammable and also a! Quench electric discharges.Dielectric liquids are used, for example, in fast pulsers for voltages above 50... And concern about the advantages and, thermal breakdown.. breakdown of dielectrics! Samples collected from a nonrenewable energy source, has affected the environment for its excellent dielectric and cooling properties causing... Is outdoors and high dielectric constants the results, both oils show higher voltage. Materials ; mineral oil for power transformers oil ( MO ) is less than of. Frequently used in the high voltage transformers care during filling the insulating material has been discussed factors affecting breakdown! Available forms of soil nitrogen as insulating oil clearly draws the following points: to environment.