Properties Of Transformer Oil Research Articles

Influence of thermal aging on dielectric characteristics of transformer insulating oils

Transformer oil is a liquid insulating material used in transformers as insulation and coolant. Particular characteristics insulating oil materials must be able to withstand breakdown voltages, while transformer oil as a coolant must be able to minimize heat generated, so that transformer oil is expected to protect the transformer from disturbances with these two characteristics. In order to reduce the percentage of transformer failures, it is necessary to maintain the purity of the oil. The features of aged transformer oil and pure transformer oil are investigated in this study. Pure transformer oil is heated to a particular temperature and cycled to create samples of aged transformer oil. The electric field intensity of transformer oil is measured to estimate the dielectric strength of aged transformer oil. FEM analysis is used to determine the intensity of an electric field. At aging temperatures of 130°C and 150°C, the dielectric characteristics of transformer oil for both Shell Diala and Triapar types are investigated. As a result, not only the electrical characteristics but also the effects of thermal aging on the physical and chemical properties of transformer oil are reported in this study.

Insight into the investigation of applying MXene nanoparticles to enhance the properties of transformer oil

Transformer oil is a refined electrical insulating oil that is widely used in power transformers and power distribution systems. The most important property of these oils is their dielectric properties, the reduction of which leads to a decrease in the lifespan of transformers. Nanofluids have a wide role in improving the properties of liquids in industrial applications. In this paper, MXene is a novel two-dimensional nanomaterial with unique properties which is added to the oil transformer to prepare a nanofluid. The Ti3AlC2 MAX phase was first synthesized from primary materials (Ti, Al, TiC), Ti3C2Tx MXenes were prepared by etching Al from Ti3AlC2 and then the MAX phases were exfoliated using hydrofluoric acid (HF) in high concentrations. X-ray diffraction (XRD), Fourier transform infrared (FTIR) techniques, Raman spectroscopy and field emission scanning electron microscopy (FESEM) confirmed that Ti3AlC2 and Ti3C2Tx were appropriately synthesized. MXene with different concentrations (0.01–0.1 wt%) was added to the used transformer oil. The results demonstrated that MXene increased the breakdown voltage, Tg delta, resistivity and relative permeability, by 31.7 %, 95.13 %, 85.15 % and 74.2 %, respectively. The study confirmed that the addition of MXene improved the dielectric properties of the transformer oil, resulting in the improved performance and stability of the transformer.

НОВАЯ ПРОТИВОКОРРОЗИОННАЯ ПРИСАДКА «РОСОЙЛ-АКОР»

The paper contains the results of laboratory tests of a new Rosoil-Akor anticorrosive additive, designed to improve the protective properties of oils for various purposes and fuels in comparison with the similar AKOR-1 additive from two Russian manufacturers. The physicochemical characteristics of the additives are defined. The effect of additives on the protective and anti-wear properties of transformer oils, motor oils and diesel fuel are studied. It is shown that the physico-chemical parameters of Rosoil-Akor additive meets the requirements of GOST 15171-78 Additive AKOP-I. Specifications. It is found that when exposed to salt fog, the protective ability of oils and diesel fuel with Rosoil-Akor additive is 3-10 times higher than with AKOR-1 additives. At higher values of relative humidity and air temperature, the protective ability of oils and diesel fuel with Rosoil-Akor additive is up to 25 times better than with AKOR-1 additives. All the additives under study increase the anti-wear properties of transformer oils, while the diameter of the wear spot of oil with Rosoil-Akor additive is 1.2-1.4 times smaller than oils with AKOR-1 additives. The addition of the studied additives to engine oils does not significantly affect the anti-wear properties of oils. The wear index of diesel fuel decreases with the addition of Rosoil-Akor and AKOR-1 additives (sample No. 1), but increases with the addition of AKOR-1 additive (sample No. 2). Test results show that the new Rosoil-Akor additive has high anticorrosive and anti-wear properties and can be used to improve the protective properties of oils for various purposes and diesel fuel instead of AKOR-1 additive.

Experimental Analysis and Physical Mechanism Investigation of Al2O3 Effect on New and Aged Transformer Oil Properties

Al2O3 nanoparticles were used to improve the performance of the vital properties of transformer oil (TO) under normal operating conditions and when subjected to thermal aging. Different weight percentages of Al2O3 in the TO were considered to maximize the breakdown voltage (BDV). Al2O3 nanofluid (NF) increases the BDV by 116% (31.1 kV to 67.4 kV) and the heat transfer by 33.4%, and also minimizes partial discharge (PD) by 66%. The reduction of PD is also related to the ability of Al2O3 to adsorb hydrogen and acetylene, two oil-soluble gases that are effective in PD. Even Al2O3NF was more resistant to water content in TO. BDV for TO and Al2O3NF, when water content increased to more than 30 ppm, were reduced by 57% and 19%, respectively. According to Arrhenius equation, both samples were placed at 120°C for 29 days to age samples (equivalent to about 30 years). Aged Al2O3NF has continued its exceptional performance and improved BDV by 121% compared to aged TO, and also Al2O3NF showed its capacity well and improved PD compared to aged TO by 71%. All the favorable properties of Al2O3NF are conditional on the stability of Al2O3. FESEM confirms the stability of Al2O3.

Effect of ferromagnetic paste on insulating properties of transformer oil

THE PURPOSE. Consider the problem of using a special ferromagnetic paste, which fills the air gaps in the magnetic circuit of an oil power transformer, in order to reduce its losses, by reducing eddy currents in the magnetic circuit. Conduct experiments to determine the dynamics of change of high-voltage breakdown of transformer oil, after adding ferromagnetic paste to it.METHODS. To solve this problem, several samples of ferromagnetic paste have been developed, differing from each other using different binding material for ferromagnetic powder. The samples were placed in containers for several days filled with transformer oil. With the help of electrical installation AIM-90, measurements of high-voltage breakdown of transformer oil of each sample were carried out. Thanks to this method, it was possible to determine how the ferromagnetic paste affects the insulating properties of the transformer oil. RESULTS. For clarity, the results of all samples were plotted. Based on the graph, it became clear that in some samples of transformer oil a significant amount of mechanical impurities formed from ferromagnetic paste appeared, which extremely negatively affected the insulating properties of the oil. There were also samples in which the properties of the oil practically did not change. CONCLUSION. As conclusions, there was a certain vision of which ferromagnetic paste can be used in the design of an oil power transformer, it was also possible to understand which samples of ferromagnetic pastes extremely negatively affect the insulating properties of the transformer oil.

Performance Detection of Transformer Oil Based on Wavelet Neural Network Optimized by Sparrow Search Algorithm

Transformer oil is an indispensable part of the transformer. The performance of transformer oil largely determines the working condition of the transformer. Therefore, it is necessary to realize accurate and rapid detection of the physical and chemical properties of transformer oil. To realize the detection of transformer oil, firstly, the ultrasonic wave with multiple frequencies is transmitted through the transformer oil, and the physical data such as penetration velocity and attenuation coefficient in the transformer oil are detected. The parameters of the wavelet neural network were optimized using the sparrow search algorithm, and the feasibility of the model was detected using the transformer oil experimental data.

Laser surface texturing under transformer oil conditions for improved process quality and tribological behaviors

Among various surface modification technologies, laser surface texturing (LST) to introduce texture has attracted more scholars' attention for controlling the tribological performance. The enhanced processing quality of the textured surface results in reducing the coefficient of friction and improving the wear resistance. In this study, dielectric transformer oil was used to protect the surface of GCr15 bearing steel from undesired gases in the atmosphere during the laser processing. Three types of dimples, including circle, rectangle and hexagon, were ablated to evaluate their influence on friction and wear. It was found that LST with transformer oil greatly improved the surface texture processing quality, where the edges of dimples were effectively designed and burrs-free. Results showed that the depth of dimples was reduced up to 7%. Compared to the samples fabricated in air, the friction coefficient and the wear of improved surface were reduced up to 55% and 73.8%, respectively. This was attributed to the excellent shielding and coolant property of transformer oil. Additionally, the shapes of the dimples, the applied force and the sliding speed significantly affected the friction coefficient, where dimples operate as lubricant and debris stores. This study provides certain feasibility guidance for the tribological modification of GCr15 bearing material with oil method and expands its application on engineering surfaces.

The effect of TiO2 doped multi-walled carbon nanotubes synthesis on the thermophysical and heat transfer properties of transformer oil: A comprehensive experimental study

The study was performed on the impact of adding hydrophobic TiO2 doped on multi-walled carbon nanotubes (MWCNTs) on the heat transfer performance, breakdown voltage (BDV), and thermophysical properties (thermal conductivity coefficient, volumetric specific heat, resistivity, diffusivity, viscosity, and viscosity index (VI)) of transformer oil (TO). The novelty of this study is the use of TiO2 doped MWCNTs nanoparticles synthesized in TO and a comprehensive experimental investigation of the properties of nanofluids. Experiments were conducted in heat transfer systems with four nanofluids, comprising TiO2 doped MWCNTs/TO at concentrations of 0.05, 0.1, 0.15, and 0.2 wt % in four input powers of 50.5, 75.6, 100, and 124 (W) in two current regimes, free air flow and forced air flow (using two blowers). For these purposes, hybrid nanoparticles were synthesized and the nanoparticles were confirmed using analyses including FTIR, XRD, SEM, and EDX. The maximum enhancement in the VI of nanofluids at 0.2 wt% of hybrid nanoparticles was equal to 34.86%. The maximum improvement in natural and forced heat transfer coefficient of nanofluids (NCHT and FCHT), which increased by 23.08% and 24.68%, respectively. According to the results, nanofluid with 0.1 wt% had good performance compared to other concentrations of nanofluids.

Soil contamination by waste transformer oil: A review

Soil pollution is the environmental problem globally as it affects the growth of plants and genetic variation. Waste transformer oil (WTO) belongs to the class of waste oils when the properties of transformer oil degraded during operation due to mechanical and electrical stresses occur in the transformer. When WTO is disposed of in landfills, the toxic substances such as PAHs, PCBs, heavy metals present in WTO get mixed with soil and increase the hydrocarbons and CO2 in the soil which results in degradation of soil quality. Heavy metals present in WTO change the activity and composition of soil microbial communities. These pollutants from soil then go into the plants and causes adverse effect on human and other living beings. Recycling and reuse of WTO can reduce the harmful effects on soil. Waste transformer oil can be used as an alternative fuel since fossil fuel reserves decreasing day by day and WTO has some properties which are similar to diesel fuel. It can also be used to produce grease and also as a base for lubricant composition for drilling muds.

Evaluation of Combustion and Emission Parameter of CI Engine Using Waste Transformer Oil as Fuel

Abstract: This project gives idea for the effective use of Waste Transformer Oil as an alternate option for petroleum based fuels. Rapid depletion of fossil fuels, increasing pollution and increasing prices of petroleum based fuels have given a base for the research of various fossil fuels. As we all know that, petroleum based fuels are limited in reserves, concentrated in certain regions of the world are shortening day by day. Huge amount of dollars are being invested in research of alternative fuels. Meanwhile, the disposal of waste products like waste transformer oil from different electric power stations from many electric transformers throughout the country is becoming increasingly complex. while biodiesel from certain vegetable oils like Jatropha, Karanja, Soyabean and Rapeseed is acquiring much needed attention. The Waste Transformer Oil is a waste product which comes out from a electrical transformer is used for insulation and cooling purpose. This waste product can be used asansource of fuel for diesel engine applications. The WTO can be used after refining it by transesterification process or catalytic cracking process and then mixed with diesel fuel as an base fuel for evaluating different engine and emission parameters and to use it as an alternate source of fuel. The engine and fuel researchers are devoted to explore alternative fuels as the present world largely depends on petroleum fuel for generating power, vehicle movement and agriculture sectors. Price hike, limited reserve of petroleum oils and stringent emission regulation also forced researchers to find alternative fuels. In Bangladesh, there is limited petroleum reserve to meet the demand of the petroleum product and for this reason it is necessary to spend a lot of foreign currency for importing fuel every year. Recent price hike of petroleum oil incurs lots of money. Bangladesh imports most of the petroleum oils from Middle East. In this point of view, waste transformer oil (WTO) can be an alternative source for petroleum oils. WTO has significant physiochemical properties. WTO can meet a portion of our demand without any hesitation. There is a huge unused amount of transformer oil in Bangladesh which is rejected every year. This oil is not used for any other purpose. So, WTO is an important source for meeting the demand of diesel in Bangladesh. Bangladesh imports approximately 2.4 million ton diesel each year . It is well known that the transformer oil is used mainly in the electrical transformer for insulation purpose. Moreover, cooling is another purpose of using transformer oil in the electrical transformer while the transformer is running. Among various properties, one of the main properties of transformer oil is to sustain high temperature during operation. When an electrical transformer is in operation, the transformer oil is subject to mechanical and electrical resistance. For a certain period of time, it is recommended to check the electrical and chemical properties of the transformer oil. By using WTO, Bangladesh can reduce importing a huge amount of petroleum products from foreign countries. Our attention goes to the WTO. WTO results from the power generation and transmission station. At present 100 per cent transformer oil is not used in place of diesel fuel (DF) to run the engine rather blends of WTO and DF. Keywords: Waste transformer oil, WTO characteristics, Diesel fuel

Study of Parameters Affecting the Aging of Transformer Oil

An electricity board acquires several transformers from a manufacturer in a belief that their advertised lifetime of the transformer thus purchased is true. However, they don’t take in the case of negligence in maintenance of transformer, which is a strenuous job. The advertised thirty-year lifetime is reduced to a mere two-year lifetime, mainly because of the degradation of the insulation medium (Transformer oil), thus increasing losses in the transformer and decreasing its efficiency. The degradation of transformer oil leads to safety hazards like transformer bursting, consequently forcing the electricity board to replace the transformer, thus incurring huge amount of costs. This is the most relatable problem faced by the electricity board in every state. This research work aims at listing out various properties of transformer oil and ascertaining major impurities in a transformer oil by testing it using various techniques. The proposed work deals with long term observation and analysis of transformer oil to determine its degradation rate. Breakdown voltage, Moisture content, Resistivity, Acidity, Furan Analysis and Dissolved Gas Analysis were done using Mushroom electrodes, Karl Fischer Titration test, Tan delta test, Potassium Hydroxide Titration, High performance liquid chromatography, and dissolved gas analyzer respectively. The results reveal that, deviation of Breakdown Voltage, Moisture content, and 2-Furaldehyde (1197ppb) from the permissible limits can indicate the aging of the transformer.

Алгоритм диагностирования изоляции силовых трансформаторов акустическим методом в условиях изменения температуры

The article presents an algorithm for processing data by the acoustic method of insulation power transformers. The article presents data processing of diagnosing by the acoustic method of power transformers. A feature of the power supply system of railway transport is the location of traction substations along the railway track. For diagnosing power transformers advisable to use portable systems based on acoustic monitoring of partial discharges due to their high mobility and ease of installation. To improve the reliability of diagnosis under the conditions of seasonal temperature changes proposed use a defect simulator and a differential method for measuring the parameters of partial discharges. The scheme of the experiment and the diagnostic algorithm are proposed. Expressions are given that describe the properties of transformer oil with temperature changes, and changes in signal parameters during the propagation of acoustic waves. The data of diagnostics obtained on a power transformer at positive and negative temperatures under conditions of development of an insulation defect accompanied by partial discharges are presented.

Current Issues Regarding the Analysis of the Physico-Chemical and Electrical Properties of Transformer Oil

Researchers and practitioners interested in the operation, monitoring and diagnosis of electrical equipment (such as: transformers, motors and generators, circuit breakers, etc.) know that in order to ensure a safe operation of such equipment it is necessary to know, among other things, the condition of the insulation system. This is one of the essential information to know because about 40% of failures which occur in the operation of the electrical equipment are due to insulation breakdown; in some cases they can reach even close to 100%. In this context this pa-per proposes the presentation of several modern methods and equipment for the study and analysis of physical and chemical properties (namely: analysis of water content, density and interfacial tension, dissolved gas analysis and furan components determination) and electrical parameters (namely: determination of loss factor and relative permittivity) of transformer oil. Samples of transformer oil type MOL TO 30.01 (uninhibited electrical insulator, non-additive), new StaSo Transformer Oil I (high quality inhib-ited insulating oil) and TR 30 oil were studied. Two samples were collected directly from the original barrel, two samples were collected from the transformer tank after dielectric tests at the transformer’s manufacturer and also two samples of used TR 30 oil were collected from two transformers. The tests were carried out in an accredited laboratory with calibrated equipment. The results highlighted the properties of each analyzed sampled. The interpretation of the results emphasized the qualities and defects of each analyzed oil sample and whether or not they fit the standards in the field.

Experimental investigation on thermal performance of covalently functionalized hydroxylated and non-covalently functionalized multi-walled carbon nanotubes/transformer oil nanofluid

The study investigated the effect of adding covalently functionalized-hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) and non-covalently-functionalized MWCNTs on the breakdown voltage and thermal properties of transformer oil in a rectangular chamber. The novelty of the present study is the use of covalently functionalized hydroxylated and non-covalently functionalized multi-walled carbon nanotubes in transformer oil, and the reason for the selection of these nanoparticles is the high intrinsic thermal conductivity compared to other nanoparticles. Between both studied nanofluids, the thermal and electrical performance of covalently functionalized MWCNTs-OH was better due to the highest increase in heat transfer coefficient of free transfer and using fan was related to covalently functionalized MWCNTs-OH, which increased by 26.23% and 30.08%, respectively. Also, by measuring the breakdown voltage, it was found that the MWCNTs-OH of 0.001 wt% had the lowest reduction compared to the base fluid and was equal to 55.6 kV, which showed good performance because the specified standard for transformer oil breakdown voltage property is between 30 kV and 70 kV. According to the results, covalently functionalized hydroxylated MWCNTs-OH/transformer oil nanofluid has better thermal performance than pure oil, which prevents the transformer from rising in temperature and can also be used as electrical insulation in transformers.

Adsorption performance of activated bentonite, zeolite 13X and activated carbon for aminophenazone in transformer oil

Aminophenazone (AP) is one kind of harmful additives in transformer oil. It results in a significant drop of the insulation property of transformer oil and thus leads to substation accidents. Adsorption method has proved to be an efficient approach for AP removal. In this work, activated bentonite, zeolite 13X, and activated carbon were chosen as adsorbents for the separation of AP from the polluted transformer oil. At 25 ℃ and initial AP content is 400 ppmw, the AP uptake of activated bentonite (151.2 mg/g) is much higher than that of zeolite 13X (52.1 mg/g) and activated carbon (45.0 mg/g). The desorption activation energy (Ed) of AP on the three adsorbents follow in the order: activated bentonite (115.73 kJ/mol) > activated carbon (52.51 kJ/mol) > zeolite 13X (51.23 kJ/mol). Activated bentonite exhibits the highest AP uptake due to the existence of acidic sites that can strongly interact with alkaline AP and the pore sizes that facilitate AP molecules to more easily enter into the adsorbent channels. Activated bentonite is an industrially promising adsorbent for the removal of AP from the polluted transformer oil.

Electrical Properties of Transformer Oil with the Addition of Extremely Low Concentrations of Carbon Nanotubes

Electrical properties of transformer oil with additives of carbon nano-tubes are studied at the extremely low concentrations of the nano-tubes. Electrical strength of the mixtures is more than an order of magnitude lower than that of pure oil. Strengthening of the large gap is registered after several breakdowns in contrast to the small gap. The formation of a carbon bridge between flat electrodes is registered optically. This bridge is destroyed by an electrical discharge in the chain of bubbles generated on the bridge. Experiments with helium bubbles floating up in the mixture of carbon nano-tubes with transformer oil are performed at the deficiency of initiating electrons. Additives of carbon nano-tubes stimulate the partial discharges in the bubbles. Also, at lower voltages, the development of intense micro-flows in the liquid dielectric is observed that can be the result of the injection of free electrons from the nano-tubes.

Improving the Thermal and Electrical Properties of Transformer Oil Using Hybrid Nanofluid

Improving the insulating and thermal properties of transformer oil is one of the factors in the use of nanoparticles (NPs) in oil. However, the use of NPs may only have a positive effect on some properties of the oil or even have a negative effect on the other properties of the oil. For this reason, hybrids nanofluid(HNF) were used to improve the properties of the transformer oil. By performing the Breakdown Voltage (BDV) test on different weight percentages (wt%) of TiO2 and CNT, it was proved that the best wt% for TiO2 is 0.0075 and for CNT is 0.001 to maximize the BDV. In this case, the HNF was able to improve the BDV and heat transfer by 9% and 8%, respectively. Another surprise that the HNF has been able to reduce the amount of C2H4 and C2H6 dissolved in oil by more than 70%. This reduction in the number of gases has another very desirable result and has reduced the PD by 63%. HNF proved that by using the right combination of different nanomaterials in transformer oil, more properties of the transformer oil can be improved.

Determination of Transformer Oil Quality Parameters by its Color Coordinates

The service life of transformers and, as a consequence, of the electric power systems depends largely on the chemical composition and electrical insulating properties of the oil. In this regard, much attention is paid to the control of physical and chemical indicators and operational properties of transformer oils. The aim of this work is to determine the important diagnostic parameters such as the acid number and the tangent of the dielectric loss angle of the transformer oil based on the measured coordinates of the color of the transformer oil. This goal is achieved by the study of the coordinates of the transformer oils chromaticity. For this purpose, a white light source is used, which is a LED with a pumping line of 450 nm and a maximum radiation in the region of 550-560 nm, with radiation in the range from 400 to 800 nm. Sensors 1, 2, 3 allow determining the chromaticity coordinates of the measured source R, G, B (red, green, blue), due to several receivers having spectral characteristics of sensitivity in the corresponding region of the visible spectrum. The most significant result of the work was the establishment of correlations between the TM chromaticity coordinatesб their acid number and the tangent of the dielectric loss angle of TM. The significance of the results obtained was that the acid number and the tangent of the dielectric loss angle of the transformer oil could be determined by the chromaticity coordinates, and hence, by the color of the oil.

Experimental investigation on thermal conductivity and viscosity of purified aged transformer oil based SiO2, Al2O3 and TiO2 nanofluid for Electric Multiple Unit Train

High voltage traction transformer of electric train demands reliable transformer oil with good heat transfer properties. Anyhow thermal stress due to high temperature initiates premature thermal ageing that deteriorates the properties of transformer oil even after multiple purification process. Influence of silicon dioxide (SiO 2), aluminium oxide (Al 2O 3) and titanium oxide (TiO 2) nanoparticles on treating purified aged transformer oil (PATO) has been addressed in this study. Oil samples were collected after validation process using colour condition standards. Each nanoparticle was suspended in the aged oil using magnetic stirrer and ultrasonic bath at 0.1% volume concentration. Stability analysis was conducted using photo capturing and zeta potential analyser method. Thermal conductivity and viscosity were investigated from temperature range of 30°C to 70°C. Based on the experimental results, PATO-based SiO 2 nanofluid was chosen as no sedimentation detected even after 144 hours with zeta potential value of 71.83mV. Thermal conductivity of PATO was enhanced up to 20.83%. Besides that, the suggested nanofluid obeys Newtonian fluid law with the viscosity enhancement up to 6.7%. On the other hand, it was found that the properties of PATO were improved with the suspension of SiO 2 nanoparticles, thus helps railway industry to optimize the life span of transformer oil.

Ester oil as an alternative to mineral transformer insulating liquid

Abstract The function of oil used in large size transformers are cooling and insulation. Transformer oil must have certain properties like high dielectric strength, low viscosity, high flash point, very low moisture or water content, high specific resistance and many more. Petroleum based synthetic and mineral oil used over last few decades, which affects the environment because of their non-biodegradability characteristics. It can be overcome by using any liquid as coolant and insulation purpose in transformer, which should have all the basic properties of transformer oil and should be biodegradable. Due to several advantages, researchers focused on biodegradable and renewable alternative of mineral oil. Ester oil has been considered as a substitute of conventional petroleum based oil. Plants of soya, sunflower and rapeseed are the sources of natural ester oil which is substitute of mineral oil. A journey of different materials used for transformer oil have been presented. Different properties of transformer oils along with the causes of failure of insulation have also been discussed. Various Ester oils have been used as an alternative to mineral oils. Different Ester oils along with their properties are also discussed.