• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.601-604
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• 1996

It is well known that steam generator water level control at low power operation has many difficulties in a PWR (pressurized water reactor) nuclear power plant. The reverse process responses known as shrink and swell effects make it difficult to control the steam generator water level at low power. A new automatic control logic to remove the reverse process responses is proposed in this paper. It is implemented in PLC (programmable logic controller) and evaluated by using test equipment in Korea Atomic Energy Research Institute. The simulation test shows that the performance requirements is met at low power (below 15%). The water level control by new control logic is stabilized within 1% fluctuation from setpoint, while the water level by YGN 3 and 4 control logic is unstable with the periodic fluctuation of 25% magnitude at 5% power.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.281-283
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• 2013

In this paper, standing water level control system and a comparison of existing methods (anchor, PDD, DM) and economic analysis was conducted. 1) Cost PDD method (6%), DM system (4%), and the SAL standing water level control system (4%), except for the anchor system is similar to the construction of three methods based on the portion of the anchor system was analyzed that. 2) construction and maintenance costs compared with the sum of the partial was, anchor system (100%), PDD method (39%), DM system (37%), the SAL standing water level control system (21%), the SAL standing water level control system was identified as the lowest cost method of.

• Journal of information and communication convergence engineering
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• 제6권3호
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• pp.337-342
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• 2008

Controlling spillway gates of dams is a complex, nonlinear, non-stationary control process and is significantly affected by hydrological conditions which are not predictable beforehand. In this paper, control methods based on dynamic fuzzy control are proposed for the operation of spillway gates of dams during floods. The proposed methods are not only suitable for controlling spillway gates but also able to maintain target water level in order to prepare a draught. In the proposed methods, we use dynamic fuzzy control that the membership functions can be varied by changing environment conditions for keeping up the target water level, instead of conventional static fuzzy control. Simulation results demonstrate that the proposed methods based on dynamic fuzzy control produce an accurate and efficient solution for both of controlling spillway gates and maintaining target water level defined beforehand.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2605-2607
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• 2000

This paper represents the construction of a PLC simulator for the level control of water and the speed control of the water cask. The level and speed processes are automatically operated by the PLC. The simulator system consists of PLC, program loader and control penal. The digital input and output units make the valves of the water cask the On or Off state. The analog input and output units control the level of water and the speed of the water cask. A LD program is used in the control language of PLC.

• 제어로봇시스템학회논문지
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• 제13권10호
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• pp.1012-1017
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• 2007

Rain data and water-level data are importantly used for dam operation at flood period. Because dams are directly controlled by the water-level data, the characteristic of the water-level gauges is necessary to be managed. Thus, we developed the standard test facility and method for testing the water-level gauges which are a float type, a supersonic type and a radar type. And we calculated the uncertainty of the standard test facility to maintain the accuracy of water-level gauges. Through development of this facility, we could obtain the characteristics and the calibration factor of the water-level gauges. And, this study showed that the standard test facility can be widely used for dam operation and basin management.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1603-1604
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• 2007

The load of power plants changes every from time to time according to which steam flow of boiler changes. the feed water control is very important for the power plant to be operated in its stability conditions. In case of circulation type boiler, the instability of feed water control leads to instability of drum level control. The higher level of drum water can induce bad quality steam to go into turbine which means the possibility of damage. The lower level of drum water can induce the tubes of boiler water wall to be overheated. In case of once through type boiler, the instability of feed water control leads to bad cooling of superheaters. The less the feed water flow is, the more heated the superheater is. It is necessary for the turbine driving feed water pump to be controlled for the optimal feed water flow in the large capacity power plant. The speed of turbine is controled for the feed water flow. By the way, the optimal control of steam valve is necessary for the speed control of turbine. Therefore, the various kinds of the steam valve structures are introduced in this paper

• 한국전자통신학회논문지
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• 제5권5호
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• pp.504-508
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• 2010

현 농촌사회는 점차 고령화 사회가 되어감에 따라 노동력 감소 문제점이 발생하고 있다. 본 연구을 통하여 생육 단계별 수위를 자동 컨트롤하여 관리할 수 있는 농작물의 수위 조절 시스템 연구 개발하였다. 수위측정에는 초음파 센서를, 급 배수로의 수문 제어에는 서보모터를 사용하고 이들의 신호를 처리하는 제어부로는 ATmega128을 사용하였다. 본 시스템을 통하여 노동력 감소의 문제점을 해결하고 농촌사회의 자동화 발전 및 고령화 사회에 큰 기여를 기대 할 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1899-1903
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• 1991

This paper presents a water level control method using Z-80 microcomputer. The process considered in this paper is one tank system which is described by an unknown nonlinear differential equation. The water level is measured by the end of bar installed at a float passing through 8 pair of photointerrupters located at equal distance. Therefore, the input data to 8255 which is interface between Z-80 and photointerrupters is discrete value, namely, value under 1. values from 1 to 8, and value upper 8. The water is pumped into the tank from a reservoir by switching on a relay connected to a moter and pump driving system. The pumping is stopped by switching off the relay. Experimental studies for two types of controllers are performed in order to investigate the control performance of water level of the water pumping system.

• 한국환경생태학회지
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• 제24권2호
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• pp.186-193
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• 2010

2006~2008년 동안 새만금 간척지에서 조성된 인공 염생식물 군락지와 새만금 방조제 배수갑문 수위 관리의 연관성을 밝히기 위해 배수갑문 수위특성 및 사유, 염생식물 군락지의 공간적인 분포와 형성 과정, 수위변화에 따른 염생식물 분포공간분석을 시도하였다. 배수갑문 수위조절의 특성을 분석한 결과, 파종 후 생장기의 평균수위와 연평균 수위와의 차이는 유사했으며, 연간 최저수위 및 최고수위가 파종 후 생장기에 나타났다. 3년동안 4,315만$m^2$에 염생식물 군락지가 형성되었으며 총 2,673만$m^2$에 대해 인공적인 염생식물 군락 조성이 시도되어 291만$m^2$을 제외한 표고 약 1m 이상의 2,382만$m^2$(89.1%)에 염생식물 군락지가 형성된 것으로 추정되었다. 파종지역 염생식물 군락지 형성에서 해수의 평균수위나 최저수위보다도 최고수위가 결정적인 요인으로 작용하였으며, 경운 및 토양 피막 여부가 군락지 형성의 2차적인 요인으로 작용한 것으로 보인다.

• 한국농공학회지
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• 제40권2호
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• pp.81-91
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• 1998

Water level of irrigation reservoir during the flood season could be kept to a certain level, so called, flood control level by releasing the flood inflow in advance in order to reduce the peak discharge of next coming flood and the damage of inundation. Concept of restriction intensity of water supply was introduced to evaluate the influence of flood control volume on the irrigation water supply. Restriction intensity can be calculated by multiplying the ratio of restriction to the days of restriction which are obtained from the operation rule curve and daily water level of irrigation reservoir and it has the dimension of % day. The method of restriction intensity was applied to the Yedang irrigation reservoir with the observed data of 30 years to review whether the present flood control volume is reasonable or not, and suggest the optimal flood control volume, if possible.