• 한국조명전기설비학회지:조명전기설비
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• 제13권2호
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• pp.178-178
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• 1999

In recent years, the electromagnetic environments are varied with the increase of power consumption and the spread of household electric appliances. Most of the interests to date have concentrated in the area of human health effects associated with exposure to power frequency electric and magnetic fields, and thus the precise measurement and analysis are required. In this paper, the measurements and analysis of the extremely low frequency(ELF) electric and magnetic fields produced by actual 22.9[kV] distribution lines were performed. The experiments have been carried out by lateral profile, and the theoretical analyses were made by use of FIELDS program for the sate of comparison with the experimental data. Electric and magnetic field intensity were strong under power distribution lines, and were inversely proportional to lateral distance. The profiles of electric and magnetic fields were M and ∩ shapes, respectively, and the measured data were good in agreement with the theoretical results. Both the electric and magnetic field intensity were increased with increasing the measurement height.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1488-1494
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• 2006

The most important thing to secure safety and reliability of railway vehicles is to verify performance characteristics of equipments, and related companies or research institutes had many efforts to verify performances and functions of equipments synthetically and efficiently. KHST(Korean High Speed Train) has been developed by KRRI(Korea Railroad Research Institute). An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.

• 한국전기전자재료학회논문지
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• 제18권2호
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• pp.153-158
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• 2005

Recently, as the feasibility study shows that trans-Korea railway and trans-continental railway are advantageous, interest in high-speed railway system is increasing. Because railway vehicle is environment-friendly and safe compared with airplane and ship, its market-sharing increases gradually. KHST(Korean High Speed Train) has been developed by KRRI (Korea Railroad Research Institute) for last 6 years to satisfy the need. An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A now method to measure temperature was applied to the measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.177-180
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• 2006

This study is to make a basic study if solid zinc (Zn) can be used for buried reference electrode, so we examined the adequacy of zinc as reference electrode by using zinc which showed regular electrode for buried period. The deference of electric potential if zinc electrode for corrosion factor such as soil resistivity or pH didn't show fixed trend and there was no clear trend on the change of measurement period. From field test, it is known that the natural electric potential difference of CSE electrode and zinc electrode is 1,100mV, but the electric potential of zinc electrode for CSE electrode in the natural soil and copying soil was 1,094~1,158mV. There was no fixed trend on the change of measurement period and electric potential difference of zinc electrode for corrosion factors such as soil resistivity or pH. Consequently, there was 40~60mV of electric potential difference in every copying soil during the experiment measurement.

• 조명전기설비학회논문지
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• 제30권2호
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• pp.78-84
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• 2016

This paper is focused on the measurement and analysis of an atmospheric electric field which is caused by thunderclouds. The electric field due to thunderclouds changes very slowly. For this reason, the extremely low frequency E-field sensor needs to be used for measuring the atmospheric electric field strength. The balloon-carried E-field sensor system with the time constant of 1sec was designed and fabricated. The electric field sensor consists of $100mm{\times}100mm$ copper plate, active integrator, high pass and low pass filters and batteries. The measurements of atmospheric electric fields were made by the balloon-carried E-field sensor and radiosonde, which sends the data back to ground in real time. From the calibration experiments, the response sensitivity of the E-field sensor was 0.154mV/kV/m in the frequency range of less than 1kHz. As a result from the actual experiment of the atmospheric electric field, the electric field signals were observed from the altitude of about 2.5km. Also, as the altitude was increased, the detected electric field wave oscillated with the fluctuation of sensing plate. The proposed method seems suitable for measurements of atmospheric electric fields, because it is inexpensive, simple to use and launch.

• KIEE International Transactions on Electrophysics and Applications
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• 제2C권6호
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• pp.287-291
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• 2002

Measurement technique of three dimensional electric field distribution in liquid dielectrics have been studied. Kerr effect and computed tomography(CT) method have been used. Measuring time has been shortened by the use of multi-optical systems to less than several milliseconds. Near future, electric field distribution in front of a streamer tip of breakdown would be measured.

• 한국전자파학회논문지
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• 제29권10호
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• pp.799-804
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• 2018

본 논문에서는 일반 측정환경에서 자유공간 물질상수 측정법을 사용한 판형 유전체의 유전율 측정 방법을 제안한다. 측정에는 회로망분석기와 동일한 두 개의 혼 안테나가 S-parameter 측정을 위해 사용되었으며, 측정 결과로부터 판형 유전체의 투과 및 반사계수를 계산하였다. 정밀한 측정을 할 수 없는 환경에서 신뢰할 수 있는 유전율을 얻기 위하여 상대적으로 측정 환경에 의한 측정불확도가 작은 투과계수의 크기만을 유전율 추정에 이용하였으며, 최종적으로 다양한 주파수에서 측정된 결과를 비교하여 유전율을 특정하였다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.437-442
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• 2005

This paper deals with the measurement and analysis of radio characteristic of 424 MHz for using the automation of transmission and supply of electric power, ana automatic meter reading(AMR). Normally radio propagation characteristic is the base of system design, performance evaluation and choice of position of the base station in wireless communication. It is the most accurate way to design a base station through practical measurements, but it costs much time, money and engineers. So, we developed 424 MHz short range wave propagation model for AMR service.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.653-657
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• 2005

The commercial contract was made firstly in the world for one set of high temperature superconducting(HTS) cable system between buyer, Korea Electric Power Research Institute and seller, Sumitomo Electric Industries, Ltd. in August 2004. After fabrication, test and examination, the HTS cable system will be installed at the KEPRI's test field in Gochang, Jeonbuk province from the time of July 2005. KEPRI is preparing measurement and test facilities for field test of the HTS cable system and carrying out researches into the design and construction of superconducting cable test building, evaluation of cooling performance, measurement of AC loss, analysis of the quench phenomena due to excess current and means of linking the HTS cable system to the existing electric power supplying system. The constitution of, the method to install and the plan of test operation of the HTS cable system will be presented in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.72-74
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• 2000

This paper presents the linear model of the measurement system with Phasor Measurement Units (PMU's) and the parallel processing technique to determinate state vectors of a power system. The conventional model of the PMU measurement system is in a dilemma that it is not applicable to optimal PMU placements and it needs more PMU to apply this model. In order to improve this defect, in this paper, the extended linear model which adaptable to optimal PMU placements considering the feature of zero injection bus is proposed. Because the proposed model is expressed as over-determined measurement equation, the efficient algorithm is needed. This paper proposed the partitioning scheme and the process algorithm for parallel determinating state vectors of a power system efficiently. The performance of the proposed linear model and the parallel processing algorithm is evaluated with IEEE sample systems.