• Transactions on Electrical and Electronic Materials
• /
• v.11 no.6
• /
• pp.288-291
• /
• 2010

Accidents can occur as a result of streaming electrification when transformer oil is used as an insulating oil in large ultra-high voltage transformers. Methods for adding a streaming electrification inhibitor to reduce the streaming electrification has been studied extensively. In this paper, in order to develop a method for reducing streaming electrification effectively, 4 different specimens were prepared by the addition of benzotriazole (BTA) to a virgin specimen with constant stirring. The specimens were examined to determine the appropriate amount of BTA addition that would suppress the streaming electrification most effectively. The results showed that the streaming electrification characteristics of the specimen in the streaming transformer oil were best when the amount of BTA addition was about 10 ppm. The streaming electrification current was reduced by adding 30 ppm BTA until the temperature reached $65^{\circ}C$. The polarity of the streaming electrification current was negative when the temperature exceeded $65^{\circ}C$. Therefore, the streaming electrification current, which can be a cause of transformer accidents, can be suppressed in large ultra high voltage transformer oil. This paper reports on the optimal amount of BTA addition and the best conditions for controlling the streaming velocity of transformer oil.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.6 no.5
• /
• pp.38-44
• /
• 1992

In this paper, electrification pipe modeled on the oil path that insulating oil flow in the high power transformer is manufactured in order to prevent the accident cause from streaming electrification generated when insulating off flow at a solid-liquid interface, and the streaming current is measured and analyzed according to the shape of oil path in electrification pipe. From the result of this study, the streaming current increases linearly with increasing of a oil velocity and it increases at lower temperature and decreases at higher temperature than [$46^{\circ}C$]. The smoother the flow of insulating oil is the more the streaming current decreases.

• Journal of the Korean Chemical Society
• /
• v.5 no.1
• /
• pp.80-83
• /
• 1961

Solution of the diffusion problem applicable to steady state reduction at the ideal streaming mercury electrode are presented, with special attention being given to the influence of stream contraction caused by the gravity. To eliminate the convection occurring in the layer between the streaming mercury and the electrolytic solution, a new method have been invented, in this case the solution being tested was streamed with same velocity of the streaming mercury. Experiment have been made in order to compare the experimental value with the theoretical value and the experimental diffusion current was approached more to the theoretical value than the value obtained by earlier form of the streaming mercury electrode used by Heyrovsky.

• Electrical & Electronic Materials
• /
• v.7 no.3
• /
• pp.236-242
• /
• 1994

In this paper, the streaming electrification characteristics of insulating oil were examined when the oil is contacted with solid materials in a circulating system. The streaming current($I_s$) increases with increasing oil velocity and temperature, and electrification properties depend on species of metal materials. $I_s$ in the gauze-contained electrification apparatus increases with increasing oil temperature below the temperature of 43[>$^{\circ}C$], but decreases above 43[>$^{\circ}C$]. On the other hand, $I_s$ is positive electrificated for the pipe of Fe, Cu, while it is negative electrificated for Sus. When insulating oil flows through a car fuel filter, $I_s$ increases linearly with increasing oil temperature.

• Journal of the Korean Society of Safety
• /
• v.20 no.3 s.71
• /
• pp.42-46
• /
• 2005

The static electricity by thinner flow and discharge energy is investigated experimentally for the purpose of preventing the electrostatic discharge and damage. Test system for evaluating streaming electrification consists of a teflon pipe, a reservoir tank a pump, flowmeters and an electrometer. When dielectric liquid flows through a pipe from one vessel to another, the potential difference generated in the collecting vessel is due to the accumulation of charges. These charges result from the convection of a part of the electrical double layer existing in the tube at the contact between the liquid and the inner wall. When the fluid velocity increases, the electric current increases proportionally. The charging current and accumulated charges by streaming electrification at the thinner velocity of 40cm/s are measured a range of 5 nA and $0.27{\mu}C$ respectively. This amount of static discharge energy generated by streaming electrification is enough to ignite flammable solvent. Therefore surface electric potential should decrease by using electrostatic shielding and ground.

• International Journal of Contents
• /
• v.17 no.2
• /
• pp.1-8
• /
• 2021

Online streaming wars are intensifying. Netflix is known as the market leader in the streaming business. However, since 2019, Netflix has been losing subscribers in the United States and is at a turning point where it needs to reassess its current position in the market. While Netflix is losing dominance, rivals Amazon Prime and Hulu continue to gain market shares. Studies from Deloitte and PricewaterhouseCoopers indicated a new shift in the streaming landscape caused by the abundance of streaming options and rising subscription costs. Recent surveys showed that consumers are excited about new streaming services, such as Disney +. Nearly two-thirds of consumers intend to terminate or downgrade one or more of their current subscriptions to make room for a new service. Moreover, it seems that consumers want ad-supported options. In Deloitte's latest Digital Media Trends survey, 65% responded that they would watch ads to eliminate or reduce subscription costs. Seventy percent of Hulu's subscribers choose its lower-priced ad-supported plan. NBC recently launched its own streaming service, Peacock, with a free ad-supported option. This opposes Netflix's brand identity of "no ads" and premium differentiation. With increasing pressure from competition and the growing risk of subscriber loss, Netflix needs to diversify its price plans. The company could try implementing the lower-priced mobile-only plan they are currently testing or plan to test in other regions. Netflix should also consider features or benefits for loyal subscribers to maintain a stronger consumer base.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.11a
• /
• pp.357-360
• /
• 1995

Since the streaming electrification phenomena of transformer were made clear on 1970s, many researches have been continued on the improvement of the transformer. This paper describes the effect of additive (BTA, DBPC) and temperature on the streaming electrification of the various materials. The streaming current in the various materials decreases in proportion to the concentration of BTA, results in the inverse electrification. We believe that these results will contribute to the optimal design of HV large-capacity transformer.

• Proceedings of the KIEE Conference
• /
• 1998.07d
• /
• pp.1436-1437
• /
• 1998

In this paper, the result of experimental investigation into the streaming electrification phenomena of insulating oil under an external dc field effect is described. Energization by positive dc voltage enhanced the streaming electrification. but when the applied voltage was negative, the polarity of streaming current was field strength dependent.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.11a
• /
• pp.329-333
• /
• 1996

In this Paper, the streaming electrification of transformer oils generated at the interface of transformer oils and the AC breakdown with impurity is studied. The electrification current is measured by the electrometer connected the faraday cage. And a oil velocity is maintained equally. In case of the AC breakdown test, the temperature are 30[$^{\circ}C$], 50[$^{\circ}C$], 80[$^{\circ}C$] and 90[$^{\circ}C$], repetitively. As a result of breakdown experiment, the dielectric breakdown strength is decreased in low temperature region and is increased in high temperature region according to increase of contained sodium. In case of streaming electrification experiment, the streaming current is more increased with the specimen contained sodium than the original specimen.

• Electrical & Electronic Materials
• /
• v.10 no.4
• /
• pp.334-341
• /
• 1997

Streaming electrification on insulating paper and pressboard under D.C. and A.C. electric field was investigated by using paper tubes and oil circulation apparatus. At first, flowing of static charges as measured with no electric field. As the temperature of oil increased, the measured current curve hows peak. As the velocity increased, it shows increasing exponential curve. Then, we applied A.C. and D.C. electric field on paper tube and the current from relaxation tank to earth was measured, which other factors such as temperature and velocity were varied like case of no electric field. The ions in oil carry the charges. So electric field makes asymmetry effect, and electrophoretic effect on ions in oil. We find that as the electric field intensity increased, the charges which were made by electric double layer were increased. The charge vs. velocity curve made peak point at a velocity.