• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.165.2-165.2
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• 2011

Flow with suction to water turbine must be in stable state at small hydraulic power plant. But because of water level fluctuation and water gate effect according to irregular supply of cooling water, it would happen to produce bubble and vortex and finally lead to problems in power-plant system. With utilizing the concept design of double size gate, surface water overflowed the overhead of gate for stable flow at suction. We developed the overflow condition and analyzed the design factor with existed one such as water level(overflow amount) and overhead of water gate(overflow figure). Flow test and CFD simulation say that flow have stable state around suction and 20% of wave reduction effect at surface layer after surface water overflow.

• 상하수도학회지
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• 제24권2호
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• pp.173-181
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• 2010

This study was conducted to investigate the possible installation of small hydro-power plant at the discharge point of Gumi sewage treatment plant (STP) using treated wastewater. Sufficient amount of water to transfer to electric power and the selection of proper location are two essential elements for the construction of small hydro-power facility. Preliminary analysis based on site visit and existing data in Gumi STP were made. Capacity of the small hydro-power plants and exact location were determined by geomorphological condition and flow duration characteristics. Flow duration characteristics and its duration curve were identified using monthly rainfall data in Gumi STP. Relevant facts of small hydro-power system in other STP were referred to adopt to Gumi STP situation. Flowrate of treated effluents and effective head between flow chamber and the location of hydraulic turbine in Gumi STP are found to be $3.70m^3$/sec and 3.5m respectively. Electric generation rate based on this feasibility study was estimated to be 86.3kW/h. Yearly electric generation rate was expected to be 932.4MMh. Proposed small hydro-power plant construction in Gumi STP is to be reasonable.

• 조명전기설비학회논문지
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• 제27권9호
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• pp.100-107
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• 2013

Since the West Sea experiences a big difference in tides, the output power of the small marine hydroelectric power plant varies with the tide. When an induction generator is used here for small hydroelectric power, the reactive power capacitor should be installed at the generator main bus to compensate for the changes in power. As such, the sizing method for the power compensation of the induction generator is reviewed and an optimal method for compensation is suggested. The self-excitation minimum capacitor capacity method, which prevents high voltages, and the power factor automatic control method, which retains a power factor of greater than 90% are reviewed. The compensation effect of reactive power is confirmed through a case study.

• 한국정밀공학회지
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• 제19권10호
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• pp.130-138
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• 2002

This paper presents the modeling and analysis of dynamic characteristics of hydraulic snubber in electric power plant. The nonlinear state-space model of 14th order to describe the dynamics of the snubber was established by Simulink. The simulation results show that the hydraulic snubber reacts as like the conventional shock absorbers against the high pulse shock load. The snubber also shows the peculiar characteristics to the small step load, which temporarily lock the control valves up, however maintain same steady-state pressures of all internal chambers in the long run. Two case studies for the analysis of the snubber were addressed. Practical pulse testing method was also proposed to identify the frequency response characteristics of the snubber.

• 연구논문집
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• 통권31호
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• pp.89-99
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• 2001

This paper presents the modeling and analysis of dynamic characteristics of hydraulic snubber in electric power plant. The nonlinear state-space model of 14th order to describe the dynamics of the snubber was established by Simulink. The simulation results show that the hydraulic snubber reacts as like the conventional shock absolvers against the high pulse shock load. The snubber also shows the peculiar characteristics to the small step load, which temporarily lock the control valves up, however maintain same steady-state pressures of all internal chambers in the long run. Two case studies for the analysis of the snubber are addressed. Practical pulse testing method was also proposed to identify the frequency response of the snubber.

• 신재생에너지
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• 제5권3호
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• pp.32-39
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• 2009

The Samcheonpo ocean small hydropower plant (SHP) has a special feature of using marginal hydraulic head of circulating water system of fossil fuel power plant as a power source and having the characteristics of general hydropower generation and tidal power generation as well. Also, it contributes to reducing green house gases and developing clean energy source by recycling circulating water energy otherwise dissipated into the ocean. The efficiency of small hydropower plant is directly affected by effective head and flow rate of discharged water. Therefore, the efficiency characteristics of ocean hydropower plant are analyzed with the variation of water level and flow rate of discharged water, which is based on the accumulated operation data of the Samcheonpo hydropower plant. After the start of small hydropower plant operation, definite rise of water level was observed. As a result of flow pattern change from free flow to submerged flow, the instability of water surface in overall open channel is increased but it doesn't reach the extent of overflowing channel or having an effect on circulation system. Performance evaluation result shows that the generating power and efficiency of small hydropower exceeds design requirements in all conditions. Analysis results of CWP's water flow rate verify that the amount of flowing water is measured less and the highest efficiency of small hydropower plant is achieved when the effective head has its maximum value. In conclusion, efficiency curve derived from water flow rate considering tidal level shows the best fitting result with design criteria curve and it is verified that overall efficiency of hydropower system is satisfactory.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.87-91
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• 1997

This paper presents the modeling and analysis of dynamic characteristics of hydraulic snubber in electric power plant. The nonlinear state equations of 9th order to describe the dynamics of the snubber was established by Sirnulink. The simulation results show that the hydraulic snubber reacts as like the conventional shock absolvers to the high pulse shock load. The snubber also shows the peculiar characteristics to the small step load, which are temporary locking displacements of control valves and same steady-state pressures of all internal chambers in the snubber.

• 대한전기학회논문지
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• 제36권7호
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• pp.492-500
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• 1987

Microcomputer-based PID governor which can be provided either stability or rapid response for small hydro power plant at low cost is developed and adapted to the 5 KW model hydro power for the performance test. The effects of PID gains on stability boundaries of the hydraulic turbine generating system is investigated. For the optimum selection of the PID gains, general equations are derived on the base of the experiments. This control system has a good performance at the model of hydro power plant. For the prediction of the control system, a mathematical model was developed and the results of the simulation using this model was matched with the experimental results.

• 한국항행학회논문지
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• 제18권3호
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• pp.254-260
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• 2014

소수력발전방식 중에서 종축 소수력 발전기를 채용한 시스템에 대해서 드럼의 수위상승에 대한 연구를 수행하였다. 드럼통에 용수를 일정하게 공급할 경우, 시간의 경과에 따라 드럼통의 수위가 상승하기는 하지만 반면, 그 상승효과 때문에 증가되는 위치에너지에 의한 러너 측 유출속도와 유출량이 증가하여 수위상승을 억제하고 그 결과 수위상승이 어느 위치에 멈추게 되어 평형상태를 이루게 된다. 이 시스템의 개발 및 분석에 의하면 드럼통의 수위는 드럼통의 크기나 높이, 폭, 형, 러너의 형상 등과는 관계 없이 결정된다. 수위는 오직 인입수량과 유출수량에 의하여만 결정되고 이에 따라 출력전력도 유사한 거동을 보인다는 것이 밝혀졌다. 그러므로 인입수량이 많지 않으면 원하는 수준의 드럼수위를 유지할 수 없을 뿐만 아니라, 원하는 출력전력도 얻을 수 없다. 아울러 현재 국내 산업시설에 설치되어 시험 운전 중에 있는 종축소수력발전시스템에 대해서 이 방법을 적용 및 수행하여 이 기법의 타당성을 입증하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제21권6호
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• pp.126-131
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• 2017

저유속 조건에서 소수력 에너지 생산 효율 증진을 위한 항력식 수직축 수차를 개발하기 위하여 전산 유체 동역학(CFD) 기법을 이용하여 수치해석을 수행하였다. 1.0~3.0 m/s의 유속 조건에서 수차 블레이드의 타공 유무에 따른 블레이드 압력 변화와 내부유동을 분석하였다. 수치해석 결과, 타공이 있는 경우 유속에 따라 수차 블레이드의 압력 및 유체 속도가 영향을 크게 받는 것으로 나타난 반면에, 타공이 없는 경우에는 유속에 따른 수차 블레이드의 압력 및 유체 속도의 영향이 상대적으로 감소하는 것으로 나타났다. 또한, 타공이 포함되지 않은 수차 블레이드에 비교하여 타공이 포함된 수차 블레이드 표면에서 압력 분포와 유체의 속도가 고르게 나타났으며, 따라서 수차 블레이드에 타공을 형성하는 것이 구조안전성 측면에서 도움이 될 것으로 판단된다.