• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권1호
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• pp.34-39
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• 2002

Most X-ray generator had been used do rectifier type transformer high tension generator which is supplied in a clinical diagnosis. But it is difficult to miniaturize and become light weight. Also, because the ripple rate of tube voltage is high, X-ray generating efficiency is very low. Therefore, it is supplied gradually from abroad being developed high tension generator for inverter type X-ray generator which use semi-conductor switching element for electric power that have high speed switching ability to solved these problem. But, semi-conductor element of big capacity are used by X-ray tube's big consumption power and diffusion is difficult in the small size hospital because production cost is ascending by doing digital control through DSP and product price becomes expensive. Therefore, in this paper, design and manufactured CR type voltage divider for feedback control of tube voltage of high frequency resonance type inverter and high tension transformer for high frequency to apply economical diffusion type X-ray generator which have wide output voltage and load extent. It is Proved do X-ray generator and stability of X-ray tube's output characteristics through an experiment.

• 한국유체기계학회 논문집
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• 제14권5호
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• pp.24-30
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• 2011

500W class MTG(Micro turbine generator) operating at 400,000 rpm is under development. From the cycle analysis, it is decided that the self-sustaining speed of MTG is 200,000rpm and the generating speed is 400,000 rpm. Therefore, motor should be designed so that it is able to rotate the rotor up to 200,000rpm and generator should designed so that it is able to generate 500W output at 400,000rpm. First step to design motor/generator is to determine the power and efficiency requirement. Not only the power into the compressor and from the turbine at the operating speed but also the mechanical and electrical losses should be considered in determining the power and efficiency requirement. This study presents the procedure and the results of determining the power and efficiency requirement considering the mechanical and electrical losses depending on the rotating speed which is measured from the experiment.

• 대한방사선기술학회지:방사선기술과학
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• 제24권2호
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• pp.5-11
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• 2001

Most of X-ray generator had used rectifier type transformer with high tension generator which is supplied in a clinical diagnosis. Because the ripple rate of tube voltage is high, X-ray generating efficiency is very low. In these days, high tension generator for inverter type X-ray generator is being supplied from a broad which uses semi-conductor switching element for the electric power that have a high speed switching ability to solve these problem. But, semi-conductor element with large capacity is used with X-ray tube's large consumption power and diffusion is difficult in the small size hospital because production cost is going up by doing digital control through DSP. Therefore, this paper designed and manufactured CR type voltage divider for feedback control of tube voltage with high frequency resonance type inverter and for high tension transformer with high frequency. It was to make economical diffusion type X-ray generator which has wide output voltage and load extent. It was preyed that the X-ray generator had the stability of X-ray tube's output characteristics.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권3호
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• pp.397-403
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• 2012

This paper describes a control method of turn-on/off angles to improve the efficiency of the switched reluctance generator(SRG) with a power closed-loop control system, and the inner-loop of the system is current hysteresis control. The SRG control system is constituted by the PI power controller and the two-level current hysteresis controller. By measuring and analyzing the system losses of different reference powers, speeds and turn-on/off angles, selection strategy of optimal turn-on/off angles is discussed. The proposed method is simple, reliable, and easy to achieve.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 추계학술대회
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• pp.57-58
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• 2017

This paper proposes a high efficiency hybrid generator which has a winding and PM(Permanent Magent) field together. The PM field can supply the enough flux to generate the no-load output voltage, and the field winding current can supply the flux to compensate the voltage drop from the load. Furthermore, the PM exciter can supply the enough power for the field of the generator. The detailed design and the FEM analysis are presented to verify the proposed hybrid generator. Then the experimental results shows the effectiveness of the proposed system.

• Journal of Advanced Marine Engineering and Technology
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• 제36권1호
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• pp.51-56
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• 2012

본 논문은 고파워 전자소자의 폐열로부터 에너지 수확을 목적으로 하는 열전생성기의 생성효율과 열적 성능에 대하여 논한다. 열경계저항을 포함하는 열전모델이 적용되어 생성효율과 고전력 전자소자의 junction 온도를 예측하였고 그 결과는 실험치로 검증되어진다. 검증결과는 예측치와 계측치의 오차가 작음을 보인다. 검증후 열전모델은 다양한 로드저항과 열원의 열율에서 생성효율, 열전생성기 양면의 온도차, 소자의 junction 온도를 예측한다. 본 연구는 로드저항이 생성효율, 열전생성기 양면의 온도차, junction 온도에 미치는 영향에 대해서도 탐구한다.

• 한국수소및신에너지학회논문집
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• 제22권3호
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• pp.313-318
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• 2011

This study is about characteristics of generating efficiency and $NO_x$ emissions of a 30 kW gas engine generator in case of using model biogas with hydrogen addition. In this case, both generating efficiency and $NO_x$ emissions are lower than the case of using urban gas (LNG). However, generating efficiency and $NO_x$ emissions are higher than the case of using model biogas only. It means that adding hydrogen which has a high flame propagation velocity has the possibility to improve the generating efficiency, but simultaneously it is also able to increase the $NO_x$ emissions of a gas engine generator.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.218-221
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• 2006

In this paper, a high-voltage generator with several mA draw output currents using LTPS-TFT technology is proposed. The new generator can be efficiently boosted about +18V output voltages with 5mA draw output currents and power efficiency ${\eta}$ is around 84% under the conditions of +5V power-supply voltage and 250kHz frequency.

• 한국전기전자재료학회논문지
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• 제24권1호
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• pp.36-41
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• 2011

Medical X-ray has been brought many changes according to the rapid development of high technology. Especially, for high-voltage generator which is the most important in X-ray generation the traditional way is to use high-voltage electric transformers primarily. However, since it is large and heavy and the ripple rate of DC high-voltage applied to X-ray tube is too big, it has a disadvantage of low X-ray production efficiency. To solve these problems, the studies about high-voltage power supply are now proceeding. At present, the high-voltage generator that generates high-voltage by making high frequency using inverter control circuit consisting of semiconductor device is mainly used. High-voltage generator using inverter has advantages in the diagnosis using X-ray including high performance with short-term use, miniaturization of power supply and ripple reduction. In this study, the X-ray high-voltage device with inverter type using pulse width modulation scheme to the control of tube voltage and tube current was designed and produced. For performance evaluation of produced device, the control signal analysis, irradiation dose change and beam quality depending on the load variation of tube voltage and tube current were evaluated.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.507-510
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• 2005

High voltage pulse power supply using Marx generator and solid-state switches is proposed in this study. The Marx generator is composed of 12 stages and each stage is made of IGBT stack, two diode stacks, and capacitor. To charge the capacitors of each stage in parallel, inductive charging method is used and this method results in high efficiency and high repetition rates. It can generate the pulse voltage with the following parameters: Voltage: up to 120kv Rising time: sub ${\mu}S$ Pulse width: up to $10{\mu}S$, Pulse repetition rate: 1000pps The proposed pulsed power generator uses IGBT stack with a simple driver and has modular design. So this system structure gives compactness and easiness to implement total system. Some experimental results are included to verify the system performances in this paper.