Negative discharge response of blend oil (ester-based insulating oil with aging mineral oil) in a non-uniform field

2017 ◽  
Author(s):  
K. Takahashi ◽  
K. Miyagi ◽  
R. Hanaoka
Keyword(s):  
Mineral Oil ◽  
Uniform Field ◽  
Insulating Oil

scholarly journals Behavior of Biodegradable Oil under Impulse Voltages

2015 ◽  
Vol 785 ◽  
pp. 320-324 ◽  
Author(s):  
Nurul Izzatul Akma Katim ◽  
Mohd Taufiq Ishak ◽  
A.M. Ishak ◽  
M.Z.A.A. Kadir
Keyword(s):  
Breakdown Voltage ◽  
Palm Oil ◽  
Coconut Oil ◽  
Mineral Oil ◽  
Electrical Performance ◽  
Uniform Field ◽  
Testing Methods ◽  
Environmental Compatibility ◽  
Impulse Voltage ◽  
Lightning Impulse

The properties of Palm Oil (PO) and Coconut Oil (CO) offer the potential for transformers with non-toxicity, high fire and flash points and better environmental compatibility while compared with those filled with Mineral Oil (MO). This potential has led to intensive studies of electrical performance of biodegradable oil especially in evaluating the electrical performance under lightning impulse voltage in recent years. This paper presents the investigation on the impulse breakdown voltage of PO and CO in such a uniform field. The PO used in this study is Refined, Bleached and Deodorized Palm Oil (RBDPO) Olein type. Two testing methods, rising-voltage and up-and-down are considered for both oils with different gap distances (2.0 mm and 3.8 mm). Testing methods including rising-voltage method and up-and-down method have no notable influence on the breakdown voltages of RBDPOs and CO compared to MO.

Breakdown Strength Characteristic of RBDPO and Mineral Oil Mixture as an Alternative Insulating Liquid for Transformer

2013 ◽  
Vol 64 (4) ◽  
Author(s):  
Yusnida M. ◽  
Kiasatina Azmi ◽  
Mohd Azmier Ahmad ◽  
Zulkifli Ahmad ◽  
Mohamad Kamarol
Keyword(s):  
Breakdown Voltage ◽  
Strength Characteristic ◽  
Palm Oil ◽  
Kinematic Viscosity ◽  
Breakdown Strength ◽  
Environmental Concern ◽  
Mineral Oil ◽  
Electrical Insulation ◽  
Insulating Oil ◽  
Insulating Liquid

Mineral oil (MO) works as an important electrical insulation and coolant in transformer which is non-biodegradable and nearly running out. Therefore, for sustainable and environmental concern, an alternative biodegradable insulating oil that potential to replace the mineral oil is introduced. In view of that, the breakdown strength characteristic of Refined Bleached Deodorized Palm Oil (RBDPO) and MO mixtures were investigated by varying the mixing percentage of RBDPO from 0% to 100% at 40oC. The results showed that the breakdown strength of the oil mixture abruptly decline to the minimum breakdown voltage of 50 kV at  20% of  RBDPO mixture and gradually increased when  the ratio of the RBDPO is added. The highest breakdown strength is achieved 87kv at 80% of RBDPO content. The result of kinematic viscosity is also presented.

Electrical Breakdown Voltage of Palm Oil and Nano Graphene Filler in Nanofluids Application on Transformer Insulating Oil

2021 ◽  
Vol 902 ◽  
pp. 59-63
Author(s):  
Kanin Wajanasoonthon ◽  
Amnart Suksri
Keyword(s):  
Breakdown Voltage ◽  
Palm Oil ◽  
Electrical Breakdown ◽  
High Viscosity ◽  
Mineral Oil ◽  
Power Transformers ◽  
Environment Friendly ◽  
Insulating Oil ◽  
Graphene Nanoparticles ◽  
Nano Graphene

Generally, power transformers have been using mineral oil as a liquid insulator due to its availability and excellent dielectric property. However, petroleum sources are depleting, which implies that mineral oil is going to be limited in availability. So, this research is to investigate on vegetable oil with nanographene filler as a substitution. Vegetable insulating oil is considered as environment-friendly insulating oil due to their superiority of biodegradable, nature-friendly, high fire-point, and good level of breakdown voltage (BV). Nevertheless, vegetable insulating oil have high viscosity, leading to a slow flow rate on the cooling performance of power transformers. To solve this problem, a process of transesterification was used to produce palm oil methyl ester (POME) from a refined bleached deodorized palm olein (RBDPO) to reduce its viscosity. RBDPO and POME were used as two kinds of fluid-based to combine with graphene nanoparticles (GNPs). Electrical breakdown voltage tests were performed by the IEC60156 standard. The results shown that POME have higher BV than RBDPO but adding GNPs may lead to lower BV even with a small amount of concentration. Nevertheless, every nanofluid has a higher BV than 30 kV.

Behavior of positive streamers in ester liquids and mineral oil in a non-uniform field with and without insulating pressboard barrier

2021 ◽  
Author(s):  
Pawel Rozga ◽  
Filip Stuchala ◽  
Dariusz Hantsz ◽  
Feipeng Wang ◽  
Zijia Shen ◽  
...  
Keyword(s):  
Mineral Oil ◽  
Uniform Field ◽  
Positive Streamers

scholarly journals Optical Chemo-Sensors for Specific Markers in Transformer Insulating Oil Exploiting Molecularly Imprinted Polymers and Plasmonic Optical Fibers

2021 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Letizia De Maria ◽  
Francesco Arcadio ◽  
Maria Pesavento ◽  
Antonella Profumo ◽  
Nunzio Cennamo ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Molecularly Imprinted Polymers ◽  
Mineral Oil ◽  
Transformer Oil ◽  
Power Transformers ◽  
Molecularly Imprinted ◽  
Insulating Oil ◽  
Insulating Liquid ◽  
Paper Insulation ◽  
By Products

2-FAL (2-furaldehyde) and furanic derivatives are the main by-products of the thermal degradation of cellulose paper insulation of power transformers’ windings. The detection of these compounds in the insulating oil of transformers is essential to investigate the ageing of the oil-paper system in order to avoid failures. To this aim, a non-conventional surface plasmon resonance (SPR) platform in plastic optical fiber (POF) was proposed for the monitoring of a biomimetic receptor specific to detect 2-FAL in transformer oil. In particular, the investigation was performed in mineral oil, which is currently the main insulating liquid for power transformers. A molecularly imprinted polymer (MIP) receptor was used, giving the sensor device a noticeable selectivity and many advantages with respect to the biological counterparts. Furthermore, the study was extended to safer and more environmentally acceptable insulating fluids representing an alternative to mineral oil (i.e., esters). To this aim, the principle and limitations of the SPR chemo-sensor performances have been discussed in this work.

Prebreakdown and breakdown phenomena under uniform field in liquid nitrogen and comparison with mineral oil

2003 ◽  
Vol 10 (6) ◽  
pp. 970-976 ◽  
Author(s):  
P.E. Frayssines ◽  
O. Lesaint ◽  
N. Bonifaci ◽  
A. Denat ◽  
F. Devaux
Keyword(s):  
Liquid Nitrogen ◽  
Mineral Oil ◽  
Uniform Field

A High Performance Energy Analyzer for Use in Electron Scanning Microscopy

1969 ◽  
Vol 27 ◽  
pp. 14-15
Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson
Keyword(s):  
High Performance ◽  
Vertical Plane ◽  
Median Plane ◽  
Electron Gun ◽  
Uniform Field ◽  
Loss Mechanism ◽  
Electron Scanning Microscopy ◽  
Sector Type ◽  
Double Focusing ◽  
Electron Energy Loss

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).

Resolution in photoelectron microscopy

1991 ◽  
Vol 49 ◽  
pp. 458-459
Author(s):  
G. F. Rempfer
Keyword(s):  
Electron Microscopy ◽  
Electric Field ◽  
Ultraviolet Light ◽  
Uniform Field ◽  
Virtual Image ◽  
Lens System ◽  
Photoemission Electron Microscopy ◽  
Planar Electrode ◽  
Electron Lens ◽  
Photoemission Electron

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.

Critical Levels of Mineral Oil Affecting the Absorption of Vitamin A

1952 ◽  
Vol 20 (4) ◽  
pp. 587-594 ◽  
Author(s):  
Frederick Steigmann ◽  
Hans Popper ◽  
Hattie Dyniewicz ◽  
Irene Maxwell
Keyword(s):  
Vitamin A ◽  
Mineral Oil ◽  
Critical Levels
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