• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.208-211
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• 2003

This paper presents an improved droop method of the high voltage DC power supply which minimizes the voltage droop of a parallel-connected power supply. Conventionally, the droop method has been used to achieve a simple structure and no-interconnections among the power sources. However, it has a trade-off between output voltage regulation and load sharing accuracy. In this paper, the droop is minimized with a current and droop gain control using steady-stage estimation. The proposed method can achieve both high performance voltage regulation and load sharing. Two 10kV, 100mA parallel power modules were made and tested to verify the proposed current-sharing method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.580-582
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• 2008

The object of this paper is develope the PC based controlled high voltage power supply and studies 1.2kW(120kV, 10mA) pulse power X-ray generator possible to adapt fluoroscopy of Dental CT X-ray generator and industrial X-ray pulse power equipment. The developed pulse power X-ray generator consisted of mono-block tank include X-ray tube and high voltage X-ray power supply circuit and high voltage control unit with RS232C/422 communication port. The PC control program of pulse power X-ray generator uses LabVIEW, and the size of high voltage transformer and high voltage generator is minimized by high voltage high frequency inverter has 100kHz switching frequency. Also this paper shows result of X-ray tube voltage and tube current correspond to variable load.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.228-230
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• 2008

A LLC resonant converter with hold-up time extension technique for computer power supply is proposed. Since the proposed circuit has a current boost-up capability of resonant inductor regardless of the input voltage level and the load power condition, operating near the resonant frequency, it can provide the power to the load as the input voltage drops to half of reflected output voltage to the transformer primary. This extends the hold-up time of computer power supply and improves the system power density and conversion efficiency at nominal input voltage. The experimental results with prototype are given to confirm the validity of the proposed circuit.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권12호
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• pp.807-812
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• 2000

With the increasing demands for clean environment, development of air cleaning systems has been received increasing attention. One of the key technologies in the electrostatic precipitator (EP) is high voltage pulsed power supply, which affects the performance of the overall system. In this study, a high voltage microsecond pulse power supply for the EP is developed for 500MW coal power plants. The power supply has dc source and a pulsed one. The ratings of the dc and the pulse source are 60kV, 800mA and 70kV, 400mA, respectively. The width of pulse voltage is 140us and the max. pulse repetition frequency is 200Hz.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.544-549
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• 2001

The effect of power supply voltage on the performance limits in a laboratory Magneto-rheological fluid based device was identified by experiments. It suggests that the frequency range of motion for control be limited by the voltage attenuation due to the coil inductance and the maximum power supply voltage set for practical use of MRF devices. In this work, the magnetic and electrical characteristics of MRF device are investigated and a design procedure is formulated to achieve the desired performance for a given power supply.

• Journal of Mechanical Science and Technology
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• 제15권11호
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• pp.1517-1523
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• 2001

The effect of power supply voltage on the performance limits in a laboratory magneto-rheological fluid based device was identified by experiments. It suggests that the frequency range of motion for control is limited by the voltage attenuation due to the coil inductance and the maximum power supply voltage set for practical use of an MRF devices. In this work, the magnetic and electrical characteristics of the MRF device are investigated and a design procedure is formulated to achieve the desired performance for a given power supply.

• 한국산업융합학회 논문집
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• 제25권3호
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• pp.423-431
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• 2022

The UPS(Uninterruptible Power Supply) system operates in the battery charging mode when the grid is normal, and in the UPS mode, which is the battery discharge mode when a grid error occurs. Since the UPS must supply the same voltage as the grid to the load within 4 [ms] in case of a grid error, the switching time and power recovery time should be short when controlling the output voltage and current of the UPS, and the power failure detection time is also important. The power outage detection algorithm using DFT(Discrete Fourier Transform) proposed in this paper compares the grid voltage waveform with the voltage waveform including the 9th harmonic generated through DFT using Schmitt trigger to detect power outage faster than the existing power outage monitoring algorithm. There are advantages. Therefore, it is possible to supply instant and stable power when switching modes in the UPS system. The multi-power-applied UPS system proposed in this paper uses DFT, which is faster than the conventional blackout monitoring algorithm in detecting power failure, to provide stable power to the load in a shorter time than the existing power outage monitoring algorithm when a system error occurs. The detection method was applied. The changeover time of mode switching was set to less than 4 [ms], which is 1/4 of the system cycle, in accordance with KSC 4310 regulation, which was established by the Industrial Standards Council on the regulation of uninterruptible power supply. A 10 [kW] UPS system in which commercial voltage, vehicle generator, and auxiliary diesel generator can be connected to each of the proposed transfer devices was constructed and the feasibility was verified by conducting an experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.253-257
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• 2003

This paper presents the Development of Switching Power Supply for testing communication equipment. The communication equipment need many kinds of voltage(-48V,27V,12V,5V,3.3V), and in case of low voltage needs large current($10{\sim}20A$). The previous Linear Power Supply was very heavy, has low efficiency and poor power-factor for testing communication equipment. This development has good efficiency and high power-factor using switch mode power supply technique. This Development of Switching Power Supply is composed of eight converters. The principles of operation, feature, and design considerations are illustrated and verified through the experiment with 600W prototype.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 추계학술대회 논문집
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• pp.47-49
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• 2007

For the magnetron, two kinds of auxiliary power is required to generate proper heat and electromagnetic field. In this paper the development of filament power supply and magnet power supply for high power industrial magnetron is studied. The filament power supply which is generate proper heat, even it doesn't require high power like main power supplies, has many consideration such as high voltage insulation and power control coordinated with high voltage cathod current to maintain constant heat generation. The novel control method using constant resistance control is proposed for accurate control of filament power supply.

• 한국통신학회논문지
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• 제27권11C호
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• pp.1132-1138
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• 2002

본 논문은 시간 제약 조건하에서의 최적 선택 공급 전압을 위한 전력 감소 스케줄링 알고리듬을 제안한다. 전력감소 스케줄링에서는 전력소비를 줄이기 위해 가변 전압 레벨을 이용해 최적 공급 전압을 선택 휴리스틱 방법으로 연산을 수행하여 제어 스텝을 결정한다. 그리고 최적 선택 공급 전압 바인딩에서는 그래프 컬러링 기법을 이용해 레지스터 상의 전력 소비의 주원인인 스위칭 활동을 최소화한다. 상위 수준 벤치마크 예제를 이용한 실험으로부터 우리는 최적 선택 공급 전압을 이용한 제안한 알고리듬이 획일화된 단일 전압을 이용한 알고리듬보다 전력 소비를 줄이는데 효율적임을 보인다.