전철화 편익 적용방안과 실증적 효과분석

문진수,김덕광 한국교통연구원 2010 交通硏究 Vol.17 No.4

This study aims at investigating the benefits of the rail electrification. The effects of rail electrification was evaluated by applying the benefits proposed in the existing study to the 31 rail projects. In the case of electrification of non-electrified railway lines, all of the four rail electrification benefits proposed in the existing study turned out to be positive additional benefits. However, in the case of construction of newly electrified railway lines, the benefit of greenhouse gas reduction turned out to be a only benefit to be considered as an additional benefit with negative impact. The analysis showed that, in the case of electrification of non-electrified railway lines, the impact of additional benefits was substantial showing 22.9% of benefit increase and the benefit increase rate was still a substantial level of 11.2% when a couple of projects with high benefit increase rate are removed from the calculation. The benefit of air pollution decrease showed the biggest impact on the increase of total benefit followed by the benefits of green house gas decrease and energy saving. The benefit of noise reduction showed the limited impact on the increase of total benefit. In the case of newly electrified railway lines, it turned out that the total benefit decreased due to the inclusion of negative benefit of greenhouse gas. However, the degree of benefit change was almost an ignorable level of -1.0%. The benefits of rail electrification are expected to contribute substantially to the increase of total benefits in rail electrification projects. Efforts are needed to include these benefits in the feasibility evaluation guidelines in Korea. 본 연구에서는 기존 연구에서 제시한 철도전철화 사업 시 발생되는 전철화 편익의 적용방안을 제시하고 실제 31개 철도 사업에 적용하여 그 효과를 실증적으로 분석하였다. 검토결과 기존선 전철화 사업의 경우 기존 연구에서 제시한 에너지 절감편익, 온실가스 절감편익, 대기오염 감소편익, 소음 감소편익이 추가편익으로 고려 가능한 것으로 나타났다. 그러나 신규 전철노선 건설사업의 경우에는 온실가스 감소편익을 불(-)편익으로 고려해야 하는 것으로 나타났다. 본 연구에서는 이러한 검토결과를 토대로 실제 31개 철도사업에 전철화 편익의 적용방안을 제시하고 전철화 효과를 분석하였다. 분석결과에 의하면 기존선 전철화 사업의 경우 전철화 추가편익을 고려 시 기존 편익 대비 편익 증가율이 평균 22.9%에 달하는 것으로 나타났으며, 일부 편익 증가율이 큰 사업을 제외할 경우에도 편익 증가율은 11.2%에 달하는 것으로 나타나 기존선 전철화 사업의 경우 전철화 추가편익의 효과는 상당한 것으로 나타났다. 한편 전철화 편익 항목별 영향도는 사업에 따라 상이하여 일반화하기 어려운 점이 있으나, 전반적으로 대기오염물질배출 편익의 영향도가 가장 큰 것으로 나타났으며, 온실가스 배출 감소편익, 에너지 절감편익 순으로 나타났다. 소음 절감편익은 전체 편익 증가에 미치는 영향이 매우 제한적인 것으로 나타났다. 신규 전철노선 건설사업의 경우 신규 열차운행에서 배출되는 온실가스로 인해 불편익이 발생하여 편익이 소폭 감소하는 것으로 분석되었으나, 총 편익에 미치는 영향도는 평균 -1%의 편익 상승률에 불과해 그 영향이 미미한 것으로 나타났다. 전철화편익은 기존선 전철화 시 편익 증대에 상당한 기여를 할 것으로 보여 타당성평가 지침에 반영하기 위한 노력이 필요하며, 전철화 편익항목의 확대 적용을 위한 연구가 이루어질 필요가 있다.

Electricity Pricing Policy Alternatives to Control Rapid Electrification in Korea

Changseob Kim,Jungwoo Shin 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.2

Although South Korea experienced a rolling blackout in 2011, the possibility of a blackout in South Korea continues to increase due to rapid electrification. This study examines the problems of energy taxation and price distortions as possible reasons for the rapid electrification in South Korea, which is occurring at a faster rate than in Japan, Europe, and other developed countries. Further, we suggest new energy taxation and price systems designed to normalize electricity prices. In order to do so, we consider two possible scenarios: the first imposes a tax on bituminous coal for electricity generation and the second levies a tax to provide compensation for the potential damages from a nuclear accident. Based on these scenarios, we analyze the effects of a new energy system on electricity price and demand. The results show that a new energy system could guarantee the power generation costs and balance the relative prices between energy sources, and could also help prevent rapid electrification. Therefore, the suggested new energy system is expected to be utilized as a basis for energy policy to decrease the speed of electrification, thus preventing a blackout, and to induce the rational consumption of energy in South Korea.

Electricity Pricing Policy Alternatives to Control Rapid Electrification in Korea

김창섭,신정우 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.2

Although South Korea experienced a rolling blackout in 2011, the possibility of a blackout in South Korea continues to increase due to rapid electrification. This study examines the problems of energy taxation and price distortions as possible reasons for the rapid electrification in South Korea, which is occurring at a faster rate than in Japan, Europe, and other developed countries. Further, we suggest new energy taxation and price systems designed to normalize electricity prices. In order to do so, we consider two possible scenarios: the first imposes a tax on bituminous coal for electricity generation and the second levies a tax to provide compensation for the potential damages from a nuclear accident. Based on these scenarios, we analyze the effects of a new energy system on electricity price and demand. The results show that a new energy system could guarantee the power generation costs and balance the relative prices between energy sources, and could also help prevent rapid electrification. Therefore, the suggested new energy system is expected to be utilized as a basis for energy policy to decrease the speed of electrification, thus preventing a blackout, and to induce the rational consumption of energy in South Korea.

Electricity Pricing Policy Alternatives to Control Rapid Electrification in Korea

Kim, Changseob,Shin, Jungwoo The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.2

Although South Korea experienced a rolling blackout in 2011, the possibility of a blackout in South Korea continues to increase due to rapid electrification. This study examines the problems of energy taxation and price distortions as possible reasons for the rapid electrification in South Korea, which is occurring at a faster rate than in Japan, Europe, and other developed countries. Further, we suggest new energy taxation and price systems designed to normalize electricity prices. In order to do so, we consider two possible scenarios: the first imposes a tax on bituminous coal for electricity generation and the second levies a tax to provide compensation for the potential damages from a nuclear accident. Based on these scenarios, we analyze the effects of a new energy system on electricity price and demand. The results show that a new energy system could guarantee the power generation costs and balance the relative prices between energy sources, and could also help prevent rapid electrification. Therefore, the suggested new energy system is expected to be utilized as a basis for energy policy to decrease the speed of electrification, thus preventing a blackout, and to induce the rational consumption of energy in South Korea.

Theoretical study of micro/nano roughness effect on water-solid triboelectrification with experimental approach

Lee, Jeong-Won,Hwang, Woonbong Elsevier 2018 Nano energy Vol.52 No.-

<P><B>Abstract</B></P> <P>The application of micro and nano surface roughness in solid-solid contact electrification based triboelectric nanogenerators (TENGs) has been a widely accepted method for pursuing higher energy output. However, the roughness enhancement needs to be reconsidered in the case of TENGs based on water-solid contact electrification because water-solid contact has clearly different interfacial behavior from solid-solid contact. This study reports a theory for investigating the effect of micro/nano roughness on water-solid contact electrification. The relation between micro/nano roughened surface and water-solid contact electrification is developed and specified by utilizing wetting and rheological properties such as fraction of the area in contact and thickness of the air gap layer. For the fabrication of water-driven TENG (WTENG), aluminum plates are anodized and fluorinated to form the dielectric layer and triboelectric layer, respectively. Three types of surface roughness were fabricated by adjusting the fabrication conditions. The WTENG with the lowest roughness shows approximately 14 times higher current and 9 times higher voltage than the WTENGs with higher roughness. The theoretical equations for water-solid contact electrification correspond well with the experimental results with high accuracy. The theory derived in this work is the first insightful perspective on roughness related liquid-solid electrification.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A precise theoretical model for water-solid triboelectrification was established. </LI> <LI> Water driven triboelectric nanogenerators with various roughness were fabricated. </LI> <LI> The experimental results well corresponded with theoretical calculation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Water droplet-driven triboelectric nanogenerator with superhydrophobic surfaces

Lee, Jeong Hwan,Kim, SeongMin,Kim, Tae Yun,Khan, Usman,Kim, Sang-Woo Elsevier 2019 Nano energy Vol.58 No.-

<P><B>Abstract</B></P> <P>A bouncing water droplet not only contains mechanical energy, but also electrostatic energy due to the triboelectric charges on its surface that are generated by its contacts with the surrounding environment. Here, we report development of contact electrification-based water droplet-driven triboelectric nanogenerator (Wd-TENG) for harvesting energy from the water-droplet bouncing between two superhydrophobic surfaces. The Wd-TENG consists of polytetrafluoroethylene balls on the bottom and zinc oxide nanosheets on the top; two surfaces of the device obtain electric energy during the contact electrification from the bouncing water, and additionally, maximize the bouncing motions of the droplets. The device produced a short-circuit current and an open-circuit voltage of 1.3 μA and 1.4 V, respectively. Besides, power-generating performances of the Wd-TENG at various angles of inclination were also investigated, and it showed voltage outputs of 5.5 V, 16 V, 9.8 V, and 6.8 V at the inclination angles of 52°, 58°, 64°, and 70°, respectively. These results demonstrate that the Wd-TENG is potentially a strong candidate for scavenging energy from raindrops.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We report development of contact electrification-based water droplet-driven triboelectric nanogenerator (Wd-TENG). </LI> <LI> The Wd-TENG consists of polytetrafluoroethylene balls and zinc oxide nanosheets to effectively harvest from dropping water. </LI> <LI> It is suggested that Wd-TENG is potentially a strong candidate for scavenging energy from raindrops. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We report development of contact electrification-based water droplet-driven triboelectric nanogenerator (Wd-TENG) for harvesting energy from the water-droplet bouncing between two superhydrophobic surfaces. The Wd-TENG consists of polytetrafluoroethylene balls on the bottom and zinc oxide nanosheets on the top; two surfaces of the device obtain electric energy during the contact electrification from the bouncing water, and additionally, maximize the bouncing motions of the droplets. It is suggested that the potential of the Wd-TENG demonstrated in this study for harvesting raindrop energy is promising.</P> <P>[DISPLAY OMISSION]</P>

Spontaneous occurrence of liquid-solid contact electrification in nature: Toward a robust triboelectric nanogenerator inspired by the natural lotus leaf

Choi, Dongwhi,Kim, Do Wan,Yoo, Donghyeon,Cha, Kyoung Je,La, Moonwoo,Kim, Dong Sung Elsevier 2017 Nano energy Vol.36 No.-

<P><B>Abstract</B></P> <P>The successive process of contact and detachment of aqueous liquid from the solid surface with its resultant net electrical charge generation is termed as “discrete liquid-solid contact electrification”, which is unobtrusively ubiquitous in our daily life. So far, the natural occurrence of discrete liquid-solid contact electrification on surfaces in nature has not been investigated and reported despite the beneficial characteristics of such surfaces. This study firstly reveals the existence of the discrete liquid-solid contact electrification phenomenon and concomitant net electrical charge generation on the natural lotus leaf surface. To advantageously utilize the generated net electrical charges, for the first time, the naturally occurring surface is directly employed to fabricate the natural lotus leaf-TENG, called the LL-TENG. The further investigation about the electricity generation is continued by altering contact material of the LL-TENG to fluoropolymer while maintaining the lotus leaf's superior surface characteristics, in a simple and cost-effective manner via thermal nanoimprinting. The artificially modified TENG not only significantly increases the amount of the generated electricity, but also shows sustained electrical output performance even after 1 month of exposure in the external dusty environment with the help of the outstanding “lotus effect”.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The existence of discrete liquid-solid contact electrification on the lotus leaf surface is discovered. </LI> <LI> For the first time, the natural leaf surface is directly employed to fabricate the triboelectric nanogenerator (TENG). </LI> <LI> .The nature-inspired approach to fabricate the TENG is demonstrated in a cost-effective and mass-producible manner. </LI> <LI> The TENG shows the sustained electrical output performance with the help of the outstanding “lotus effect”. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

무기체계 전력화 지연이 미치는 손실비용에 대한 연구

박주홍,최명진 한국산업경영시스템학회 2023 한국산업경영시스템학회지 Vol.46 No.4

The Korean military has sought to build an all-round military force against the national and international security environment and future asymmetric threats as well as the military threats it faces. However, while raising the need for timely electrification, there are few cases of quantitatively evaluating the loss when electrification is delayed, making it difficult for our military to provide a logical basis to support the importance of the electrification period. Therefore, through this study, we tried to analyze the index of loss cost that can support the need for timely electrification with logical and quantitative data and present it as a logical basis. To this end, the loss cost was calculated in terms of combat efficiency, equipment utilization rate, and maintenance requirements, which can be quantitatively calculated based on “combat readiness,” a general impact on the military in case of delayed timely electrification.

Couette 흐름현상을 이용한 초고압변압기의 유동대전 기구 연구

곽희로,정용기,권동진 한국조명전기설비학회 1995 조명.전기설비 Vol.9 No.4

The purpose of this paper is to analyze the streaming electrification mechanism (SEM) generated in UHV transformer. This experiment used Couette Charger and interpreted the mechanism hydromechanically and electromagnetically. This work estimated the turbulent core density ($\rho$o) by measuring the short circuit current (isc) and the open circuit voltage (νoc) generated in Couette Charger and also studied the changes of the short circuit (isc), the open circuit voltage (νoc), the turbulent core density ($\rho$o) and the conductivity ($\sigma$) with adding BTA to restrain streaming electrification. as a result adding BTA increased the conductivity of oil and decreased the turbulent core density($\rho$o).

Effect of the Addition of Benzotriazole on the Streaming Electrification Properties in Transformer Oil

Shin, Jong-Yeol,Hong, Jin-Woong The Korean Institute of Electrical and Electronic 2010 Transactions on Electrical and Electronic Material Vol.11 No.6

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.