• Title/Summary/Keyword: Power Standards

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A Study on Standardization of UPS (Uninterruptible Power Supply) for Traffic Signal Controller (교통신호제어기용 무정전전원장치 용량기준 연구)

  • Ko, Kwang-Yong;Lee, Choul-Ki;Kim, Min-Sung;Heo, Nak-Won;Jeong, Jun-Ha
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.5
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    • pp.1-6
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    • 2012
  • Unlike the past, modern urban intersections have dramatic growth in size and utilizations. As a result, continual traffic signal control is essential. Hence the individual or regional electrical blackout may bring about uncontrollable traffic congestion. Late summer of 2011 a regional blackout brought about traffic nightmare not including time and revenue loss associated with this disaster. Due to this disaster our national police agency and other government agencies are in process of introducing an UPS (uninterruptible power supply) system into essential intersections. This study estimates the power consumption necessary to sustain at least 2 continuous hours for a standard four-legged intersection. Prototype was studied using these standards. The field experiment of prototype showed positive results and was able to meet standard guidelines set forth. Prototype tested was able to meet standards in medium to large capacity of traffic size.

Economic Effect of National Measurement Standards (측정표준의 국민경제 기여효과 분석)

  • 안병덕;남경희;안웅환;김동진;조연상
    • Journal of Korea Technology Innovation Society
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    • v.5 no.2
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    • pp.245-256
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    • 2002
  • Measurement standards, as being widely recognized, is necessary for national economic development and advanced industrialization. Also measurement standards give reliability and fair trade to the producers and consumers. Macro-effect of measurement standards using estimation of cost function has four effects: 1) value-added causing effect, 2) effect of employment, 3) reduction effect transaction cost, 4) reduction effect defect rates. In this study, to investigate the impacts between specific and the other industries, we used I-O Table of Korea Bank. The relation between the value-added produced by original production factors and final use is determined through production level, and the relation can be investigated with production causing coefficient matrix. In this study, it was showed that the measurement standards investments including measurement only man power of industries were increased from 1995 rapidly. The establishment and maintenance of measurement standards contributes to reduce the defect rate of products in production process and improve the confidence of the product quality. The results from this study show that measurement technology contributes to improve quality, decrease defect rate, improve production process, develope new products, reduce prime cost and increase the consumer's confidence on the firms. Since these results indicate that measurement standards are very important in the point of their vast contribution, we hope our findings can contribute to encourage measurement activities in industries.

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Principles and Comparative Studies of Various Power Measurement Methods for Lithium Secondary Batteries (리튬이차전지 출력측정법의 원리 및 측정법간 비교 연구)

  • Lee, Hye-Won;Lee, Yong-Min
    • Journal of the Korean Electrochemical Society
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    • v.15 no.3
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    • pp.115-123
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    • 2012
  • As the market of lithium secondary batteries moves from mobile IT devices to large-format electric vehicles or energy storage systems, the strengthened battery specifications such as long-term reliability longer than 10 years, pack-level safety and tough competitive price have been required. Moreover, even though high power properties should also be achieved for hybrid electric vehicles, it is not easy to measure accurate power values at various conditions. Because it is difficult to choose a proper measurement method and its experimental condition is more complex comparing to capacity measurement. In addition, the power values are very sensitive to power duration time, state-of-charge (SOC) of cells, cut-off voltages, and temperatures, whereas capacity values are not. In this paper, we introduce three kinds of power measurement methods, hybrid pulse power characterization (HPPC) suggested by US FreedomCar, so-called J-pulse by Japan electric vehicle association standards (JEVS) and constant power measurement, respectively. Moreover, with pouch-type unit cells for HEV, experimental power data are discussed in order to compare each power measurement.

Computational Simulation on Power Prediction of Lithium Secondary Batteries by using Pulse-based Measurement Methods (펄스 측정법에 기반한 리튬이차전지 출력 측정에 관한 전산 모사)

  • Park, Joonam;Byun, Seoungwoo;Appiah, Williams Agyei;Han, Sekyung;Choi, Jin Hyeok;Ryou, Myung-Hyun;Lee, Yong Min
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.33-38
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    • 2015
  • Energy storage systems (ESSs) have been utilized widely in the world to optimize the power operation system and to improve the power quality. As lithium secondary batteries are the main power supplier for ESSs, it is very important to predict its cycle and power degradation behavior. In particular, the power, one of the hardest electrochemical properties to measure, needs lots of resources such as time and facilities. Due to these difficulties, computer modelling of lithium secondary batteries is applied to predict the DC-IR and power value during charging and discharging as a function of state of charge (SOC) by using pulse-based measurement methods. Moreover, based on the hybrid pulse power characteristics (HPPC) and J-Pulse (JEVS D 713, Japan Electric Vehicle Association Standards) methods, their electrochemical properties are also compared and discussed.

Seismic Performance Evaluation and a Comparative Study on the Design Wind and Earthquake Loads for Power Transmission Towers (송전철탑의 내진성능평가 및 설계 풍하중과 지진하중의 비교 연구)

  • Hwang, Kyeong-min;Chun, Nak-hyun;Jang, Jung-bum;Yun, Kwan-hee;Kim, Tae-kyun
    • KEPCO Journal on Electric Power and Energy
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    • v.5 no.2
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    • pp.75-81
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    • 2019
  • In this study 24 power transmission towers were selected by considering various variables such as power transmission capacity, height and structural type to evaluate their seismic performance using the standard design response spectrum recently announced by the government. In addition, the stresses and sectional forces generated by the current design wind loads and revised seismic ones were compared to review the effects on the design of power transmission towers when the government-required seismic standards were raised. The results of seismic performance evaluation for the target power transmission towers showed that they had seismic capacity of 0.31~0.91g, and that they met the level of the earthquake-resistant special grade, which is the 2,400-year earthquake return periods and secured seismic safety. Further, the sectional forces caused by earthquakes in the towers were 33~82.5% of the ones due to wind loads, and it was also confirmed that the design wind loads were more dominant than design earthquake ones under the elevated seismic standards.

Precision time sync. HW/SW platform for power system protection (전력시스템 보호를 위한 정밀 시각 동기 적용 HW/SW 플랫폼 기술)

  • Nam, Kyung-Deok;Son, Kyu-Jung;Chang, Tae-Gyu;Kang, Sang-Hee
    • Journal of IKEEE
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    • v.22 no.4
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    • pp.1036-1043
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    • 2018
  • This paper presented future power system protection technologies through the HW/SW integration platform with IEC 61850 and IEEE c37.238 standards. To determine the implementation performance of the integrated platform, an example of EVM (Evaluation Module) was constructed to satisfy the standards. The platform has been identified as a future power system integrated IED(Intelligent Electronic Device) HW/SW technology that meets the level of error required by the time sync standard and the level of delay required by protecting the power system.

A Study on Standards of Wheelchair User Accessible Toilet Rooms (휠체어사용자용 화장실의 규격기준에 대한 연구)

  • Shin, Dong-Hong;Park, Kwang-Jae
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.24 no.4
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    • pp.27-35
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    • 2018
  • Purpose: The diverse users and the increase of power wheelchair users have made it difficult to apply the standards of Wheelchair user accessible toilet rooms for the existing law and BF-certification. To address these issues, the standards of the relevant laws have been improved (Ministry of Health and Welfare, 2018), but there are still many problems. In this study, problems with the standards for Wheelchair user accessible toilet rooms in Korea are analyzed by comparing national and international standards. In addition, improvements to standards for Wheelchair user accessible toilet rooms will be suggested. Method: It presents improvement for standards of Wheelchair user accessible toilet rooms by comparing national, international standard and standards of many countries. Korean standard, International Standard(ISO 21542), American Standard(ADA Standards), German Standard(DIN 18040-1), Austrian Standard($\ddot{O}NORM$ B 1600) and Swiss Standard(Norm SIA 500) were investigated and analyzed. Results: Korea's standards differ from the ISO and the Standards of other countries in many ways, so there is a need for realignment. Specifications for disabled toilets and clear criteria for the size, shape, and location of sanitary appliances in toilets that are practically available to wheelchair users should be provided. Considering the increasing number of disabled toilet users, the installation of various disabled toilet rooms should be considered considering the user characteristics of those who can walk and wheelchair users. Implication: Recent partial improvements to relevant laws cannot meet the requirements of various users. Therefore, comprehensive and clear standard should be presented that take into account changing society and the environment.

Electron Density and Electron Temperature in Atmospheric Pressure Microplasma

  • Tran, T.H.;Kim, J.H.;Seong, D.J.;Jeong, J.R.;You, S.J.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.152-152
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    • 2012
  • In this work we measured electron temperature and electron density of a microplasma by optical emission spectroscopy. The plasma is generated from a small discharge gap of a microwave parallel stripline resonator (MPSR) in Helium at atmospheric pressure. The microwave power supplied for this plasma source from 0.5 to 5 watts at a frequency close to 800 MHz. The electron temperature and electron density were estimated through Collisional-radiative model combined with Corona-equilibrium model. The results show that the electron density and temperature of this plasma in the case small discharge gap width are higher than that in larger gap width. The diagnostic techniques and associated challenges will be presented and discussed.

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