• JOURNAL OF ELECTRICAL WORLD
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• no.9 s.129
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• pp.71-76
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• 1987

부하변동이 격심하고 또한 단속사용이 많은 용접기는 부하 중에서도 특이한 것이라고 하겠다. 그 용접기에 전력을 공급하는 전원측은 어떻게 대처해야 될것인가. 변압기의 용량선정을 중심으로 차단기 등에 대해서도 전기설비기술기준령, 내선규정 등을 참고로 하면서 해설한다.

• Proceedings of the KIEE Conference
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• 1983.07a
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• pp.167-169
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• 1983

• 전기의세계
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• v.43 no.4
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• pp.20-26
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• 1994

전력계통은, 발전기, 변압기, 모선, 선로등을 주요소로 한 많은 설비요소로 구성되며, 이들이 일체로 되어 하나의 안정상태를 유지하면서 운용되고 있다. 전력계통 구성요소중, 특히 가공선로는 지역적으로 널리 분포되어 있으므로, 뢰, 풍우, 염분 등 자연 현상의 영향을 받아 단락, 지락등 계통사고 발생이 불가피하며, 또 다른 구성요소들도 각각 고유한 사고형태와 사고빈도를 가지고 있다. 보호방식은 이들 각종 설비에 사고가 발생하였을 때에, 신속히 사고설비를 계통에서 제거하여, 사고 전류의 계속으로 인한 설비손상을 방지하는 것을 그 기본목표의 하나로 하고 잇다. 그러나 사고발생은 단지 설비의 손상을 가져올 뿐만 아니라, 하나의 안정상태를 유지하고 운용되고 있는 전력계통 전체에 대해서, 이 안정을 무너뜨리는 방아쇠로 작용하며, 사고의 계속, 또는 사고제거에 따른 계통구성의 급변등은 주파수의 저하, 계통탈조, 설비과부하등으로 파급되어 전계통 붕괴로 확대될 가능성을 가지고 있다. 이러한 경향은 전원의 원격화와 집중대용량화, 선로조류의 증가등으로, 계통이 복잡화함에 따라 더 증대하고 있다. 이러한 배경을 바탕으로 하여 보호방식의 책무는, 종전의 설비보호 위주에서 사고파급방지에 의한 계통보호(protection for power system disturbance)로 그 중점목적이 옮겨가고 있으며, 이 사고 파급방지보호장치를 계통안정화장치라고도 한다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.306-307
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• 2011

제 4차 전력 수급 기본 계획에 의하면 2022년 계통에는 총 32기의 원자력 설비와 신재생 설비 용량의 약38%를 차지하는 풍력 설비가 신규 도입 된다는 것을 확인 할 수 있다. 하지만 원자력과 신재생에너지원은 화력 설비에 비해서 부하추종 능력이 저조하여 이 두 설비의 비율을 높이면 계통 운영에 심각한 문제를 발생 시킬 수 있다. 이에 본 논문에서는 2022년 off-peak 계통 상황에서의 원자력 설비 32기가 모두 연계되었을 때, 계통 주파수의 안정도를 분석하고자 하였다. 이를 위해 계통에서 사용하는 각종 정수를 추정하고 이것을 이용하여 주파수 분석 시뮬레이션 tool을 통해 주파수 변화를 모의 하였다. 최종적으로 2022년 계통에서의 최적 전원 설비 구성을 제안하고자 한다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.5 no.2
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• pp.49-57
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• 1991

A simple system to measure the correlated color temperature ($T_c$) and color rendering index ($R_a$) oflight sources was developed. And the T, and R, of incandescent lamps (I/L) and various fluorescent lamps(F/L) were measured with varying source voltage and power frequency. As results, $T_c$ variations of I/L and F/L with varying source voltage were relatively large, but $R_a$, variations were small. And $T_c$, $R_a$, variations of F/L under 5OkHz of power frequency were small, but over 50kHz, it is supposed that $T_c$, and $R_a$, will vary significantly.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.2 no.2
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• pp.59-63
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• 1988

In a fixed AC power source the PWM techniques were used to vary the voltage and the fundamental frequency. The conventional PWM techniques due to the problem of commutation number and filter size have been studied the PWM output waveforms which applied the motor drive. However in this paper, the carrier frequency with sinusoidal PWM waveform is modulated from 10(KHz) to 45(KHz) using termination devices with high - speed switching capacity and applying LPF(Low Pass Filter) with small capacity to output of inverter and the PAM(Pulse Amplitude Modulation)is obtained. Considering the property of the speed and the control, the sinusoidal PWM control circuit was composed of the microprocessor and analog circuit. In experment result, the system properties are study on the sinusoidal voltage waveform with modulation index changing from 0.6 to 1.0.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.55-61
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• 1998

Generally, in the calculation of ground resistance in the grounding system, the method measuring ground potential rise which is caused by low frequency source injection is used. But both lightning and surge impulse re very harmful to electric equipment. In this connection, this paper presents the results of an experimental investigation of transient behavior of ground impedances when lightening current is injected to the electric rod the experimental results are agreement with the theoretical analysis. In addition, the states on the behavior of ground electrodes under impulse currents due to lighting strokes are presented. And the impulse impedance reductions caused by discharge in the soils are presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.65-71
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• 2006

The number of elevator installation increases every year about 15,000. The number of confine-disease of elevator increases every year and then sudden in, sudden stop, error of level indication, stand; those can bring to uneasiness of elevator passenger and malfunction related life accident is increasing. Therefore we researched elevator repair diary of elevator repairing company, APT management office and 119 life rescue for elevator confine-disease during 2004. 1. 1.${\sim}$12. 31. we analyzed the content and the time type and cause of the malfunction and fault for APT elevator. Form the result of 119 life rescue, only power reset is 24[%] and only power failure is 8.2[%] by cause of confine-disease. This paper will be used data of the analysis for mutual relation between Power Quality and malfunction and fault of elevator.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.5
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• pp.90-96
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• 2002

The AC power lines and signal lines of info-communication networks are muted on overhead poles and are exposed to lightning strikes. Due to the potential difference between groundings of the AC power lines and telecommunication lines, the electronic equipments connected to the telecommunication lines can easily be damaged by lightning surges. In this work, in order to develop the reliable ways to protect information and communication facilities from lightning surges, the reliability and performance of surge protective devices were experimentally investigated in actual-sized test circuit. The operation behaviors of surge protective devices against lightning surges from the AC power lines and telecommunication lines and the coordination effects of SPD installation method were evaluated. As a consequence, it was confirmed that the bypass arrester and common grounding system is very effective.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.4
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• pp.109-116
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• 1997

This paper describes the surge protective device combined with varistor and LC low pass filter on AC power circuits. Up to now varistors alone have been used as a surge protective device on AC power circuits, but it gives negative effects on the equipments to be protected due to the steep rise and high remnant voltage. Therefore in this work, for the purpose of improving the cutoff performance of surge protective device on AC power circuits, the hybrid-type surge protective device with varistor and LC filter was designed and prepared. And the experiments for operational characteristics and clamping performance of the surge protective device were carried out with an 1.2/50[$\mu$s] impulse generator. As a result, the proposed surge protective device with the combination of varistors and LC filter can limit the surge voltage to lower value and reduce the value of dV /dt to very small values. Also the attenuation of high-frequency voltages across the output port is effectively provided by LC filter. Therefore this result may be all the more helpful avoiding both damage and upset of electronic systems.