scholarly journals Experimental Investigation on Vegetative Oils under Accelerated Thermal Ageing against Their Dielectric Strength

2017 ◽  
Vol 7 (3) ◽  
pp. 1588
Author(s):  
Siti Sufiah Abd Wahid ◽  
Mohd Fikri Hilmi Mohd Taib ◽  
Yanuar Z. Arief ◽  
Mohd Hafizi Ahmad ◽  
Noor Azlinda Ahmad ◽  
...  
Keyword(s):  
Power Transformer ◽  
Research Work ◽  
Dielectric Strength ◽  
Mineral Oil ◽  
Thermal Ageing ◽  
Transformer Oil ◽  
Accelerated Ageing ◽  
Insulation Material ◽  
Low Dielectric ◽  
High Dielectric

Insulation is one of the most important parts in high voltage apparatus such as power transformer. Most power transformer use liquid insulation material, known as power transformer oil. Petroleum-based oil so called mineral oil has been used for many years as power transformer oil. This is due to its high dielectric field strength, low dielectric loses and good long-term performance. This research work has been carried out to investigate the effect of thermal accelerated ageing on electrical properties for several vegetative-based oils. The oil samples that have been used in this research work are soy bean-based oil (FR3) and commercial palm-based oil (PFAE). As comparison, Hyrax mineral oil has also been investigated. The results revealed that vegetative-based oils have as well as dielectric strength compared with mineral oil.  It was found that the dielectric strength for all oil samples decreased when undergo the thermal accelerated ageing process.

Influence of electrical and thermal ageing on the mineral insulating oil performance for power transformer applications

2020 ◽  
Vol 62 (4) ◽  
pp. 222-231
Author(s):  
C Ranga ◽  
A Kumar ◽  
R Chandel
Keyword(s):  
Power Transformer ◽  
Stress Test ◽  
Oxidation Stability ◽  
Chemical Properties ◽  
Mineral Oil ◽  
Thermal Ageing ◽  
Test Cell ◽  
Transformer Oil ◽  
Power Transformers ◽  
Solid Dielectrics

In the present work, a new electrothermal combined stress test cell has been designed and fabricated to conduct accelerated electrothermal ageing. The fabricated test cell includes all possible real working conditions of the transformers. The effects of accelerated electrothermal ageing on the performance of power transformers with thermally upgraded Kraft (TUK), Nomex-910 and Nomex-410 solid dielectrics in conjunction with mineral oil have been investigated. The accelerated electrothermal ageing has been performed for a temperature range of 100°C to 220°C, along with 10 kV electrical stress. Subsequently, several electrical, thermal, mechanical and chemical properties of transformer oil and different paper dielectrics have been determined. It has been observed from the diagnostic test results that Nomex impregnated mineral oil samples have better electrothermal performance as well as oxidation stability when compared to the thermally upgraded Kraft oil samples. Therefore, Nomex insulating materials in conjunction with mineral oil are suggested as alternative solid dielectrics for power transformers in order to achieve better oxidation stability, improved thermal performance for long service runs and reduced operating and maintenance costs. It is envisioned that the present experimental study will be very beneficial to utility managers and end-users of power transformers.

scholarly journals Pengujian Sifat Fisika dan Listrik Minyak Kelapa Sebagai Alternatif Isolasi Pada Trafo Daya

2021 ◽  
pp. 174-185
Author(s):  
Ni Made Seniari ◽  
Sumawarti Sumawarti ◽  
IK Wiryajati ◽  
Supriyatna Supriyatna ◽  
I.A.Sri Adnyani ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Physical Properties ◽  
Power Transformer ◽  
Coconut Oil ◽  
Dielectric Strength ◽  
Transformer Oil ◽  
Added Value ◽  
Insulation Material ◽  
Test Results ◽  
Renewable Materials

Transformer oil insulation material is the result of processes from petroleum, the material that is not able to be renewed, increasingly scarce, expensive, an imported commodity, and the need is increasing. So it is necessary to strive for alternative transformer oil that comes from renewable materials, based on domestic production, increases the added value of a commodity and environmentally friendly. The alternative transformer oil in this case is coconut oil. For this reason, it is necessary to test the feasibility of coconut oil as an alternative to transformer oil which includes testing of physical, chemical and electrical properties. The test results are compared with the standard transformer oil according to the IEC. The test results, the flashpoint and dielectric strength are feasible as an alternative to transformer oil, the density, volume expansion coefficient and viscosity of coconut oil are not suitable for use as an alternative to power transformer insulation oil. The percentage in terms of physical properties is 25%, with 4 tests of 10 existing physical properties. The feasibility of electrical properties is 50% with 1 test of 2 existing electrical properties.

Adhesion and Dielectric Strength of Ultra-Low Dielectric Constant PTFE Thin Films

1997 ◽  
Vol 476 ◽  
Author(s):  
C.T. Rosenmaver ◽  
J. W. Bartz ◽  
J. Hammes
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Strength ◽  
Low Dielectric Constant ◽  
Thermal Treatments ◽  
Test Results ◽  
Low Dielectric ◽  
Metal Insulator Metal ◽  
Thickness Standard ◽  
High Dielectric

AbstractPrevious work has demonstrated the potential of polytetrafluoroethylene (PTFE) thin films for ULSI applications. The films are deposited from PTFE nanoemulsions. They have an ultra-low dielectric constant of 1.7 to 2.0, a leakage current of less than 1.0 nA/cm2 @ 0.2 MV/cm and a dielectric strength of from 0.5 to 2.4 MV/cm. They are thermally stable (isothermal weight loss < 1.0 %/hr at 450 °C), uniform (thickness standard deviation < 2%), and have excellent gap-fill properties (viscosity of 1.55 cP and surface tension of 18 mN/m). The films are inert with respect to all known semiconductor process chemicals, yet they are easily etched in an oxygen plasma.This paper discusses the processing technology that has been developed to process PTFE films with these properties. Specifically, it addresses two recent discoveries: 1) Good adhesion of spin-coated PTFE to SiO2 surfaces; and 2) high dielectric strength of PTFE thin films spin-coat deposited onto rigid substrates. The adhesion-promoting and thermal treatments necessary to produce these properties are detailed. Stud pull test results and test results from metal-insulator-metal (MIM) capacitor structures are given.

Preparation of Aramid Mica Composite Insulation Material

2011 ◽  
Vol 214 ◽  
pp. 16-20 ◽  
Author(s):  
Xiao Wei Zhang ◽  
Shu Peng Liu ◽  
Yu Peng Qian ◽  
Ying Bo Zhu
Keyword(s):  
Composite Material ◽  
Heat Resistance ◽  
High Strength ◽  
Dielectric Strength ◽  
Insulation Material ◽  
Aramid Fibers ◽  
Insulation Property ◽  
Mica Composite ◽  
High Dielectric ◽  
Paper Insulation

While mica papers are used as insulation material binders and reinforcement materials are needed to enhance the mechanical strength which might reduce insulation property of mica paper materials. In this paper aramid fibers and mica flakes are mixed to make composite paper insulation, both have the high strength, heat resistance of aramid fibers and high dielectric strength, corona resistance of mica flakes. When this composite material is preparing, process of mix pulp papermaking was chosen, combined with mica flake and aramid fiber modification. Prepared composite material has properties of high tensile strength, dielectric strength, heat resistance, softness, can be used as high quality insulation.

Condition Monitoring of High Voltage Transformer using Dissolved Gas Analysis Methods

2021 ◽  
Vol 9 (VI) ◽  
pp. 1759-1770
Author(s):  
Dayyala Ravi
Keyword(s):  
Power Transmission ◽  
Power Transformer ◽  
Accurate Method ◽  
Mineral Oil ◽  
Gas Analysis ◽  
Transformer Oil ◽  
Dissolved Gas ◽  
Voltage Transformer ◽  
Transformer Protection ◽  
Dissolved Gas Analysis

Power transformer plays a significant role in the entire power transmission network; thus, transformer protection requires more attention for fault free electric supply. when the mineral oil and insulation inside the transformer is subjected to high thermal and electrical stresses, gases are created by the decay of mineral oil and cellulose. Different gases create different faults, Identification of faults inside the power transformer before they occur reduces its failure rate during its service period. For Knowing the fault condition of power transformer, Dissolved Gas Analysis (DGA) is proven to be as accurate method based on combination of concentration of gases like CO, CO2, H2, C2H6, C2H4, C2H2 etc., Dissolved gas analysis is the most important test in determining the fault condition of a transformer and it is the first indicator of a problem and can identify deteriorating insulation and oil, overheating hot spots, partial discharge and arcing. For developing this DGA Techniques, the MATLAB GUIDE interface can be used for making easy interaction between the user and software developed. This software is designed using some conditional statements and logical functions to get the type of faults in transformers based on the concentration of gases in transformer oil. The faults in transformer using dissolved gases analysis are detected using methods such as key gas, Roger’s methods, IEC ratio, Doernenburg ratio, Duval triangle and the Combined DGA methods. In this paper, these four methods of dissolved gas analysis (DGA) are presented and explained briefly.

Characteristics of Mineral Oil-based Nanofluids for Power Transformer Application

2017 ◽  
Vol 7 (3) ◽  
pp. 1530 ◽  
Author(s):  
I. H. Zakaria ◽  
M. H. Ahmad ◽  
Y. Z. Arief ◽  
N. A. Awang ◽  
N .A. Ahmad
Keyword(s):  
Electrical Properties ◽  
Breakdown Strength ◽  
Power Transformer ◽  
Atmospheric Pressure Plasma ◽  
Mineral Oil ◽  
Transformer Oil ◽  
Before And After ◽  
Cold Atmospheric Pressure Plasma ◽  
The Stability ◽  
Physical Changes

Trends in the field of nanomaterial-based transformer oil show most of the conducted works have focused only on the transformer oil-based nanofluids but limited studies on the stability of transformer oil-based nanofluids. Since mineral oil-based nanofluids still can produce the sedimentation, thus the cold-atmospheric pressure plasma method is proposed to functionally modify the Silicon Dioxide (SiO<sub>2</sub>) nanofiller in order to enhance the electrical properties of the mineral oil-based nanofluids. The AC breakdown strength oil samples before and after modification were measured. It was found that the plasma treated nanofluids have higher AC breakdown voltage compared to pure oil and untreated nanofluids. Also, Fourier Transform Infrared (FTIR) Spectroscopy has been used in this study to analyse the physical changes of oil samples. It is envisaged that the added silica nanofiller has significant effect on electrical properties of the transformer oil-based nanofluids which would enable to the development of an improved class of liquid dielectric for the application of power transformer.

Research of the thermal aging mechanism of polycarbonate and polyester film

e-Polymers ◽  
2017 ◽  
Vol 17 (1) ◽  
pp. 45-56
Author(s):  
Wei Wang ◽  
Dongxin He ◽  
Kai Yang ◽  
Shiyuan Liu ◽  
Shu Song ◽  
...  
Keyword(s):  
Thermal Aging ◽  
Power Transformer ◽  
Polymeric Materials ◽  
Decomposition Temperature ◽  
Transformer Oil ◽  
Gravimetric Analysis ◽  
Insulation Material ◽  
Scanning Calorimetry ◽  
Insulating Paper ◽  
Polyester Film

AbstractInsulating paper is a traditional insulation material used for transformer insulation. Transformer development is not only limited to small sizes and large capacities, but also limited to insulation life as insulating paper cannot withstand high temperatures. Therefore, recent studies have focused on improving the performance of insulation paper and discovering better insulation materials. In this study, two types of polymeric materials, polycarbonate (PC) and polyester film (PET), were chosen for comparative analysis. In order to test whether these two materials could be used in oil-immersed transformers, the PC and PET were placed in transformer oil for thermal aging at 110°C and 130°C, respectively. The thermal cracking processes and fragmentation mechanisms of the PC, PET, and insulation paper were analyzed using thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and atomic force microscopy (AFM), as well as their degrees of polymerization and surface morphologies. According to the test results, the initial thermal decomposition temperature of PC and PET are higher than insulation paper and exhibited a better thermal resistance. PC and PET have the potential to substitute insulation paper for large capacity power transformer.

scholarly journals Methanol Marker for the Detection of Insulating Paper Degradation in Transformer Insulating Oil

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3969 ◽  
Author(s):  
Jalbert ◽  
Rodriguez-Celis ◽  
Arroyo-Fernández ◽  
Duchesne ◽  
Morin
Keyword(s):  
Kinetic Studies ◽  
Field Measurements ◽  
Field Testing ◽  
Thermal Ageing ◽  
Degree Of Polymerization ◽  
Transformer Oil ◽  
Accelerated Ageing ◽  
Insulating Paper ◽  
Field Samples ◽  
Solid Insulation

This manuscript presents a comprehensive literature review with the aim to provide readers a reference document with up-to-date information on the field of methanol use as a chemical marker. It has been a little more than a decade since methanol was first introduced as a marker for assessing solid insulation condition in power transformers. It all started when methanol was identified in the laboratory during thermal ageing tests carried out with oil-immersed insulating papers and was subsequently also identified in transformer field samples. The first publication on the subject was released in 2007 by our research group. This review covers the methanol fundamentals such as the analytical methods for its determination in transformer oil, which is generally performed by headspace gas chromatography with mass spectrometry or flame ionization as a detector. Current standardization efforts for its determination include ASTM working group 30948 and IEC TC10. Kinetic studies have confirmed the relationship between methanol generation, the number of broken 1,4-β-glycosidic bonds of cellulose and changes in mechanical properties. Laboratory tests have confirmed its stability at different accelerated ageing temperatures. Several utilities have identified methanol during field measurements, case studies on power and some distribution transformers are presented, as well as transformer postmortem investigations. These field-testing results demonstrate its utility in monitoring cellulosic insulation degradation. Recently, a model of methanol interpretation has become available that allows for evaluation of the average degree of polymerization of core type transformer cellulose winding. Methanol has a role as an indicator of cellulosic solid insulation ageing in transformer mineral oil, and it is expected that in the future it will be in routine use by utilities.

scholarly journals Investigation of the Dielectric Strengths of Locally Sourced Vegetable Oil as an Alternative to Mineral Based Transformer Oil

2020 ◽  
Vol 5 (6) ◽  
pp. 366-369
Author(s):  
Prof. Eze,Anthony N ◽  
Dr. Okoye,Peter I.
Keyword(s):  
Dielectric Constant ◽  
Moisture Content ◽  
Vegetable Oil ◽  
Pour Point ◽  
Dielectric Strength ◽  
Mineral Oil ◽  
Transformer Oil ◽  
Sample Collection ◽  
Value Determination ◽  
Electrical Transformers

The main purpose of the study was to investigate the dielectric strengths of locally produced vegetable oils from Nigerian farms to compare the dielectric strength of the vegetable oil with the mineral oil to see if vegetable oil can be used as an alternative for insulating and cooling of transformers. It was an experimental research. The experimental procedures adopted in carrying out the investigation were sample collection, processing of sample and storing and testing for different properties such as pour point, flash point, peroxide value determination (aging), moisture content, and breakdown voltage test were conducted and results obtained. The findings of the study indicated that vegetable oil has the highest dielectric constant when placed on the same temperature with the mineral oil. One of the recommendations was that owners and managers of electrical transformers should see the urgent need of using vegetable oil as alternative to mineral oil.

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