• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.569_570
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• 2009

This paper presents a methodology to find the profit maximized Nash Equilibriums of each generator(or GenCo), which considers the Ramp-rate of each generator under a competitive market environment. The ramp-rate of a generator is one of the physical or technical constraints of a generator and means the ability to increase or decrease the output instantaneously. In this paper, we found several Nash Equilibriums of the generation allocation problem through Dynamic Programming in a competitive market. Individual generators participate in a game to maximize its profit through competitions and play a game with bidding strategies of its generation quantities in a spot market.

• 전기학회논문지
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• 제60권3호
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• pp.509-516
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• 2011

This paper studies a novel method to find the profit-maximizing Nash Equilibriums in allocating generation quantities with consideration of ramp-rates under competitive market environment. Each GenCo in a market participates in a game to maximize its profit through competitions and play a game with bidding strategies. In order to find the Nash equilibriums it is necessary to search the feasible combinations of GenCos' strategies which satisfy every participant's profit and no one wants various constraints. During the procedure to find Nash equilibriums, the payoff matrix can be simplified as eliminating the dominated strategies. in each time interval. Because of the ramp-rate, generator's physically or technically limits to increase or decrease outputs in its range, it can restrict the number of bidding strategies of each generator at the next stage. So in this paper, we found the Nash Equilibriums for multi-stage generation allocation game considering the ramp-rate limits of generators. In the case studies, we analyzed the generation allocation game for a 12-hour multi-stage and compared it with the results of dynamic economic dispatch. Both of the two cases were considered generator's ramp-rate effects.

• 전기전자학회논문지
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• 제11권1호통권20호
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• pp.38-45
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• 2007

A new 8-bit single-slope ADC using analog RAMP generator with digitally controllable dynamic range has been proposed and simulated for column level or per-pixel CMOS image sensor application. The conversion gain of ADC can he controlled easily by using frequency divider with digitally controllable diviber ratio, coarse/fine RAMP with class-AB op-amp, resistor strings, decoder, comparator, and etc. The chip area and power consumption can be decreased by simplified analog circuits and passive components. Proposed frequency divider has been implemented and verified with 0.65um, 2-poly, 2-metal standard CMOS process. And the functional verification has been simulated and accomplished in a 0.35$\mu$m standard CMOS process.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.293-298
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• 2005

The following is final report for governor upgrade for PWR NPP safety related EDG Kori NPP No.2 Unit. The upgraded system includes more beneficial function like as "Slow start with starting ramp", "Generator load sensing & control capability" and "Emergency ramp during slow start". This paper show functional operation of slow start regime according to NRC regulatory guide which guide regulation to NPP safety related environment.

• 대한전자공학회논문지SD
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• 제43권1호
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• pp.59-64
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• 2006

단일 기울기 ADC에 사용되는 램프 신호의 기울기는 공정과 주파수 변화에 민감하다. 이러한 변화는 ADC 이득 변화와 이미지 신호 프로세싱의 성능까지 영향을 준다. 본 논문에서는 자동 교정된 램프 신호를 이용한 단일 기울기 ADC를 이용하여 공정과 주파수 변화에 영향을 받지 않은 CMOS 이미지 센서를 제안하다. 본 논문에서 제안된 built-in-self-calibration (BISC) 구조는 공정과 주파수 변화에 상관없이 입력 조도별로 일정한 출력 값을 갖는 단일 기울기 ADC 동작을 가능하게 한다. 제안된 BISC를 탑재한 CMOS 이미지 센서는 $0.35{\mu}m$ 공정을 이용하여 제작하였다. 측정 결과는 제안된 구조가 공정이나 클럭 주파수의 변화에 따라 효과적으로 램프 기울기를 교정한다는 것을 보여준다. 칩 면적의 증가 정도는 $0.7\%$ 미미하였다.

• 센서학회지
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• 제24권4호
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• pp.252-257
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• 2015

This paper proposes a single slope A/D converter (SSADC) that is possible to process the signal of the ultraviolet, visible and infrared rays with a single chip. And the proposed SSADC is a type of single channel ADC. In the conventional SSADC, it is possible to process the only one signal with a kind of the sensor because the speed of the operating frequency and the slope of ramp signal generated by the ramp generator are fixed. In order to improve the disadvantages, a ramp generator which has variable slope in ramp function is designed and $3{\times}1$ MUX(multiplexer) is adopted so that we can change the speed of the operating frequency and the slope of ramp signal. Therefore, the multiple signal processing of the wanted sensors can be possible. The designed circuit is layout by the $0.35-{\mu}m$ CMOS 2-poly 4-metal technology process and is checked through DRC and LVS tools.

• 대한전자공학회논문지SD
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• 제47권6호
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• pp.13-21
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• 2010

본 논문에서는 가변 펌핑 클록 주파수를 이용한 모바일 D랩용 고효율 승압 전압 발생기를 제안한다. 제안된 승압 전압 발생기는 효율을 높이기 위해서 3단 Cross-coupled 점하 펌프를 사용하였으며, 또한 최종 출력 전압의 승압 시간을 줄이기 위해 기존의 승압 전압 발생기에서 사용되는 고정된 펌핑 클록 주파수 대신 전압 제어 발생기를 사용하여 펌핑 클록 주파수을 가변하였다. 따라서 제안된 승압 전압 발생기는 1.2 V 전원 전압, 최대 2 mA의 부하 전류, 1 nF의 부하 캐퍼시터 조건에서 24.0-${\mu}s$안에 3.0 V의 최종 출력 전압을 승압할 수 있다. 실험 결과 제안된 승압 전압 발생기는 에너지 소비를 26% (1573 nJ $\rightarrow$ 1162 nJ), 승압 시간을 29% (33.7-${\mu}s$ $\rightarrow$ 24.0-${\mu}s$) 감소시켰다. 따라서 제안된 승압 전압 발생기를 사용함으로써, 높은 에너지 효율과 빠른 승압을 동시에 구현할 수 있다.

• Journal of Electrical Engineering and Technology
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• 제3권3호
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• pp.320-330
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• 2008

This paper presents an improved dynamic programming (IDP) approach to solve the economic power dispatch problem including transmission losses in power systems. A detailed mathematical derivation of recursive dynamic programming approach for the economic power dispatch problem with transmission losses is presented. The transmission losses are augmented with the objective function using price factor. The generalized expression for optimal scheduling of thermal generating units derived in this article can be implemented for the solution of the economic power dispatch problem of a large-scale system. Six-unit, fifteen-unit, and forty-unit sample systems with non-linear characteristics of the generator, such as ramp-rate limits and prohibited operating zones are considered to illustrate the effectiveness of the proposed method. The proposed method results have been compared with the results of genetic algorithm and particle swarm optimization methods reported in the literature. Test results show that the proposed IDP approach can obtain a higher quality solution with better performance.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.581-583
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• 2005

The paper is final report for speed control upgrade and analysis report which recently performed on PWR NPP safety related EDG KHNP Ulchin NPP No.2 Unit. The upgraded system includes more beneficial function like as 'Slow start with starting ramp', 'Generator load sensing & control capability' and 'Emergency ramp during slow start'. This paper shows functional operation of slow start regime according to NRC regulatory guide which guide regulation to NPP safety related environment.

• 전기학회논문지P
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• 제63권4호
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• pp.254-259
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• 2014

In this paper, we describe construction of a wind stabilization demo-site and effects of output power control of wind turbines for suppression of ramp rate using ESS (Energy Storage System). It is difficult to control the output power of distributed generator such as wind turbine which of variation is very large. If the large capacity wind farm be interconnected into power system may cause blackout due to Power Quality. For these reasons, the international standards such as Grid-Code is limited to less than 10 [%/min] of renewable energy ramp rate. The case of Korea, government actively conducts propagating large-scale renewable energy for green growth policy, to interconnecting more renewable energy into power system is necessary for stabilization technology. For these reasons, the POSCO consortium has constructed a wind stabilization demo-site that is configured as 500 [kWh] battery energy storage systems can output up to 3 [C-Rate] and two wind turbines rated 750 [kW]. In POSCO consortium, which implements various methods stabilizing output power of wind turbine such as smoothing, section firming and ramp control, we derive the results of long-term demonstration that can be controlled to satisfy to the international standard about ramp rate [%/kW] of wind turbine output power.