• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.93-102
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• 1998

This paper describes to control system for AC to DC converter which has been widely used to power source in industrial factory and domestics. In this paper, three-phase PWM AC to DC Boost converter that operates with unity power factor and sinusodial input line currents is presented. The current control of this converter is based on the predicted current control strategy with fixed switching frequency and the line currents track to reference currents within one sampling time interval. By using this control strategy low ripples in the output current and the voltage as well as fast dynamic response are achieved with small dc link capacitance employed.ployed.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2164-2165
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• 2011

본 논문에서는 직렬아크 고장 시 발생하는 전류파형의 특징인 전류의 shoulder의 검출을 통하여 아크고장을 판별하는 직렬아크 고장 검출기를 제안하였다. 또한 정상적인 동작에서 발생하는 전류의 shoulder를 아크신호로 판단하지 않기 위한 방법을 제안 하였으며 이를 시뮬레이션을 통해 확인하였다.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.439-440
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• 2012

최근 LED의 빠른 성장과 새로운 개발이 이루어지면서 이를 이용한 응용제품의 개발과 기존 조명을 대체하려는 연구가 활발히 진행 되고 있다. 기존의 LED PCB Ass'y와 구동드라이브는 분리형으로 Size및 소자의 개수가 많아 cost및 신뢰성 부분에 제약이 따른다. 이에 대한 보완점을 찾기 위하여 본 연구에서는 새로운 LED 구동 드라이브를 제안하였다. 회로의 부하를 LED Module로 구성하여 피크 전류를 완화하여 LED 동작 및 전류제어가 가능 하고, 부하에 저항만 있을 때의 전압, 전류의 출력파형이 플리커 현상을 보이는 부분이 사인파로 조정된 모습을 확인 할 수 있다. 본 연구 에서는 기존 LED 드라이브의 많은 제약적인 부분을 보완하기 위해 출력되는 전압, 전류의 파형이 부하에 따라 변화하는 모습을 시뮬레이션을 통해 검증하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.425-431
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• 2011

The harmonic distortion level may be significant in electric propulsion systems, as the main loads usually are variable speed propulsion/thruster drives. Distortion of currents and supply voltage waveforms may lead to: Increased power dissipation(losses) in equipment connected to the network, such as generators, motors, transformers, cables, etc., from the harmonic currents, may cause overheating and deterioration of the insulation, and reduced life time of the equipment. In this paper introduced the canceling method of harmonic currents by a multipulse drive with phase shifting transformer. The simulation results indicated a good speed response to the middle speed range of electric propulsion motor. And also, THD(total harmonic distortion) and torque ripple could be reduced in comparing the 12-pulse drive with 6-pulse drive.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1761_1762
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• 2009

본 논문은 자동차 연료 펌프의 수명을 결정짓는 연료펌프용 DC모터의 브러시-정류자간의 전압, 전류 특성을 분석 하는 것이다. 기존의 DC모터 실험으로는 정류자와 브러시 표면상태 확인이 어렵고 코일 전류 파형 및 브러시-정류자간 전압 강압 파형이 측정 불가했다. 그리고 모터의 L값을 변화 시킬 수 없기 때문에 다양한 조건의 실험이 불가 하였다. 이러한 단점을 보완하여 브러시-정류자간 전압 파형을 측정을 하기 위해 시뮬레이터를 개발하는 것이 본 논문의 주제이다.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.3
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• pp.107-118
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• 1995

The characteristics of the current waveforms and 3$\Phi$ power waveforms of the variable speed 3$\Phi$ AC motor system driven by the single-pulse PWM investigated in this paper. The system is composed of a digital bridge inverter and low pass LC filter. It is confirmed that current waveforms and 3$\Phi$ power waveforms can be improved by utilizing the high order low pass LC filter than that of lower order through computer simulation. Also, we propose the low pass LC filter revised from the conventional LC filter.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.185-188
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• 2008

An apparatus for serial arc in UL 1699 is implemented Current waveforms of arc and a nonlear load are investigated and a method of arc detection can be considered. Introduction of digital signal processing technologies is suggested to correctly detect arcs of electrical fire pyrognostics. This study is expected to be utilized as the basis of such arc detection researches.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.235-237
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• 2000

본 연구에서는 SRM의 설계 단계에서 일반적으로 얻을 수 있는 자속 쇄교-전류 곡선으로부터 SRM의 토크-속도 특성 곡선을 예측하는 방법을 제시한다. B-스플라인 함수를 이용하여 SRM에 가해질 수 있는 상전류 파형을 모두 모델링하고 각각의 회전자의 속도에서 최대의 토크를 낼 수 있는 전류 파형을 구한다. 제안된 방법은 상전류 제어뿐만 아니라 스위칭 각도 제어까지 고려한 모든 상전류 파형을 표현할 수 있기 때문에 SRM이 최적으로 동작하는 상황에서의 토크-속도 특성임을 보장할 수 있다. 제안된 방법은 SRM의 설계 단계에서 별도의 제어기 설계 없이 간단히 성능을 평가할 수 있는 방법이다.

• Fire Science and Engineering
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• v.34 no.4
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• pp.1-6
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• 2020

In this study, the authors measured voltage and current waveforms in real time during a serial arc discharge. The analysis results of the arc discharge radiation patterns exhibited intermittent discharge, arc growth, creation of a heat generating area, occurrence of plume, and formation of a red heat area, which proceeded in that order. When the serial arc discharge was introduced, the current and voltage waveforms exhibited periodicity as sine waves. It was also observed that a restriking transient voltage occurred when the waveform changed from positive (+) to negative (-) and vice versa. When the discharge proceeded, the amount of heat generated for 1 s and 600 s was approximately 0.317 mJ, and 190 mJ, respectively. The duration of the short circuit was approximately 1.66 ms, and in the case of the voltage waveform, it was evident that the electric potential increased to 49.9 V in the same cycle. Furthermore, when the discharge proceeded, the effective value (RMS value) of the current was approximately 1.72 A with a maximum current of approximately 2.53 A, whereas the effective value of the voltage was approximately 42.8 V with a maximum of approximately 208 V.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.1
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• pp.82-88
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• 2000

In this paper, We present a low cost auxiliary circuit of $S^4-PFC$converter with the feedback winding, which can improve the input current waveform with the maintenance of limited DC Bus Voltage and high efficiency. The converter with feedback winding was analyzed to demonstrate the proposed converter. Int order to verify the performance of the proposed converter, we designed the converter which operates at the output of 5[V], 65[W] and switching frequency of 100[kHz] within the universal line voltage. Implemented converter has decreased line current peak value by 50[%] compared with the conventional converters and the power utilization was increased in the line period.