• JSTS:Journal of Semiconductor Technology and Science
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• 제7권4호
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• pp.241-246
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• 2007

This paper presents two novel compensation circuits for leakage current and power supply noise (PSN) in phase locked loop (PLL) using a nanometer CMOS technology. The leakage compensation circuit reduces the leakage current of the charge pump circuit and the PSN compensation circuit decreases the effect of power supply variation on the output frequency of VCO. The PLL design is based on a 32nm predictive CMOS technology and uses a 0.9 V power supply voltage. The simulation results show that the proposed PLL achieves 88% jitter reduction at 440 MHz output frequency compared to the PLL without leakage compensator and its output frequency drift is little to 20% power supply voltage variations. The PLL has an output frequency range of 40 $M{\sim}725$ MHz with a multiplication range of 1-1023, and the RMS and peak-to-peak jitter are 5psec and 42.7 psec, respectively.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권11호
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• pp.628-634
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• 2002

A capacitor-charging power supply using high frequency inverter technology is strongly recommended for the charging section of the pulsed power supplies. A high frequency inverter swiching makes the overall system size small. The command-charging feature can guarantee the higher reliability of switching function. The protection circuit can be easily included in the system and the good regulation of charging voltage can be acieved by the feedback system. Several modules can be stacked to supply required output power and a failed module can be easily replaced. A 50-kV, 35-kW capacitor charging power supply is developed. In this paper the detailed design and test results of a prototype unit are presented.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.185-191
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• 2006

Auxiliary power supply developed by domestic technology has very important function that not only effect on main power converter & inverter system, traction motor and train control system which are related to performance of train, but also influence on power supply for HVAC(Heat, Ventilation, Air-conditioning) and lighting device which are related to comfort of passengers. This paper shows characteristic test results of auxiliary power supply such as working condition and performance, which is associated with velocity of train, operating mode and surrounding equipment, through test running. Also it shows the results deduced from comparison analysis between designed data and manufactory test data as measuring in put voltage of auxiliary power supply. And, it propose a modification of design parameter for stabilizing operation and improving reliability.

• 한국철도학회논문집
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• 제10권1호
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• pp.84-87
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• 2007

Auxiliary power supply developed by domestic technology has very important function that not only effect on main power converter & inverter system, traction motor and train control system which are related to performance of train, but also influence on power supply for HVAC(Heat, Ventilation, Air-conditioning) and lighting device which are related to comfort of passengers. This paper shows characteristic test results of auxiliary power supply such as working condition and performance, which is associated with velocity of train, operating mode and surrounding equipment, through test running. And, it propose a modification of design parameter for stabilizing operation and improving reliability.

• 한국정보기술학회논문지
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• 제16권12호
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• pp.101-107
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• 2018

다양한 분야에 적용이 확대되고 있는 무선 센서 네트워크 기술은 센서들의 전력공급 및 전원관리 문제가 가장 큰 핵심이 되고 있다. 이러한 이유에서 새로운 개념의 전력공급장치와 전원관리장치가 요구된다. 이에 본 논문에서는 송전선에 흐르는 전류를 이용하여 전자기유도 원리에 의한 에너지 하베스팅 기술을 적용하여 별도의 외부 입력 없이 센서노드에 안정적인 전력을 공급하는 자율독립전원 시스템을 개발하였다. 제안한 자율독립전원 시스템은 Power CT를 활용한 전력공급장치와 충전회로를 포함한 전원관리장치로 구성되었다. 전원관리장치는 배터리의 충전의 안전성을 확보하기 위하여 전압제한회로, 충전전압/전류 모니터링 회로를 적용하였다. 제안된 시스템의 성능검증을 위하여 SVL진단장치에 적용하여 실험한 결과 안정적으로 운용됨을 확인할 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 추계종합학술대회
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• pp.758-761
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• 2003

전원장치의 소형화 핵심기술인 반도체 스위칭 기술을 이용하여 단일 전원을 사용하는 소형, 경량화 전자기기에 적합한 5 V/500 mA급 트랜스리스형 파워 모듈(transless type power module)을 설계하였다. 파워 모듈은 강압형 chopper 방식을 이용한 스위칭회로, 제어회로, 전압검출회로, 그리고 정전압 회로 둥으로 구성되어 있으며, 하이브리드-집적회로형(hybrid-IC type)으로 제작되었다. 본 연구에서 설계한 스위칭 레귤레이터 전원회로는 5 V/500 mA급 트랜스리스형 파워 모듈의 전기적 특성을 만족하였다.

• 산업기술연구
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• 제26권B호
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• pp.135-144
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• 2006

The significance of hydro-power plant is increasing in its public roles such as flood control and water supply as well as electric power production. Even if high level of reliability in facility operation is required, no specific reliability research has been made. This specifically stems from the lack of technology and research investments. The eventual goal of this study is to secure a methodology for reliability analysis of hydro-power plant so that an appropriate decision for operation and investment can be made. Specific effort was put to develop a reliability model for water supply system within hydro-power plant. For this study, we briefly examined the overview of the hydro-power plant including the electric power generation facility system. We then discussed the facility reliability analysis methodology for hydro-power plant. Based on rigorous examination of the water supply system and components roles, we drew major failure modes for each component and examined their effects.

• 신재생에너지
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• 제5권4호
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• pp.34-37
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• 2009

Using six SMD(surface mount device) type AlGaAs/GaAs single junction solar cells connected in series, a power source was fabricated for a white GaN LED. The electrical properties of the power source was measured and analyzed under one sun (100mW/$cm^2$) and various indoor light (300 - 900 lux) conditions. Under 600 lux indoor light condition, output power was 17.06 ${\mu}W$ and it was 30.75 ${\mu}W$ under 900 lux indoor light condition. Using the fabricated solar cell power supply, we have turned on the white GaN LED. It was worked well under 15 ${\mu}W$(at 480 lux) power supplied from solar cell array. This kind of solar cell power supply can be used as a power source for ubiquitous sensor network (USN).

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 추계학술대회 논문집
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• pp.267-272
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• 1999

The auxiliary power supply system fur passenger service of railway car has been developed from MA(Motor-Alternator) to CVCF Inverter (Static Inverter). Generally, a customer wants to apply tile new control method and device for auxiliary power supply of railcar However, if the auxiliary power supply is supplied to extended existing line, the maintenance cost of the old system is less expensive than new developed system, so, the customer specifies that the auxiliary power supply has compatibility with existing one completely. At that time, the hardware is nearly same as existing system except small changes of accessories for better performance. This paper describes the flicker control using feed-forward method of auxiliary power supply system for new 50 electric railcars, which are delivered to Korean National Railroad (KNR) Kwa-chon Line. The existing power supply system has damping resistor box to stabilize the DC input (1.5 ㎸). At this time, for better system efficiency the new system has not include resistor box but new control method including feed-forward control is applied. This control algorithm realizes the better stabilization of input power compared to the result of the existing system, which includes resistor box

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권1호
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• pp.47-54
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• 2004

A new high voltage DC power supply is proposed. The proposed power supply is constructed with several power converters connected in series. It is easy to obtain high DC voltage for the same structure of each power converter. The output DC power of the proposed power supply can be disconnected from the load within several hundred microseconds at the instant of a load short-circuit fault. The rising time of the output DC voltage is also as small as several hundred microseconds, and there is no overshoot of the voltage because all of the output filter capacitors keep undischarged state even in load short-circuit condition. Therefore, the proposed scheme is suitable for the protection of frequent output short-circuit and fast on/off switching of output DC voltage. The proposed power supply has improved features such as simple structure, high power factor, and reduced size and volume compared with the conventional schemes. The operating principle is described and the validity of the proposed scheme is proved through simulations and experiments.