• 한국태양에너지학회 논문집
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• 제40권4호
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• pp.23-33
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• 2020

The loss in photovoltaic power due to hailstorms has been highlighted as a major issue in the sustained growth of the PV power plant industry. This study investigates the safety of a solar module by conducting a numerical analysis of a hail test according to the IEC 61215 standard. Our study aims to elucidate the detailed behavior between the ice and solar modules and the micro-cracks forming on solar modules during hailstorms. To analyze the impact of hail, we used the ANSYS AUTODYN software to evaluate the impact characteristics on a solar module with different front glass thicknesses. The simulations show that a solar module with a glass thickness of 4.0 mm results in excellent durability against hail. The results indicate the feasibility of using simulations to analyze and predict micro-cracks on solar modules tailored to various conditions, which can be used to develop new solar modules.

• International Journal of Fluid Machinery and Systems
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• 제10권2호
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• pp.146-153
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• 2017

Sediment flow through hydropower components causes hydro-abrasive erosion resulting in loss of efficiency, interruptions in power production and downtime for repair/maintenance. Online instruments are required to measure/capture the variations in sediment parameters along with collecting samples manually to analyse in laboratory for verification. In this paper, various sediment parameters viz. size, concentration (TSS), shape and mineral composition relevant to hydro-abrasive erosion were measured and discussed with respect to a hydropower plant in Himalayan region, India. A multi-frequency acoustic instrument was installed at a desilting chamber to continuously monitor particle size distribution (PSD) and TSS entering the turbine during 27 May to 6 August 2015. The sediment parameters viz. TSS, size distribution, mineral composition and shape entering the turbine were also measured and analysed, using manual samples collected twice daily from hydropower plant, in laboratory with instruments based on laser diffraction, dynamic digital image processing, gravimetric method, conductivity, scanning electron microscope, X-ray diffraction and turbidity. The acoustic instrument was able to capture the variation in TSS; however, significant deviations were found between measured mean sediment sizes compared to values found in the laboratory. A good relation was found for turbidity ($R^2=0.86$) and laser diffraction ($R^2=0.93$) with TSS, which indicated that turbidimeter and laser diffraction instrument can be used for continuous monitoring of TSS at the plant. Total sediment load passed through penstock during study period was estimated to be 15,500 ton. This study shall be useful for researchers and hydropower managers in measuring/monitoring sediment for hydro-abrasive erosion study in hydropower plants.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1999년도 추계 학술발표회 논문집
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• pp.231-236
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• 1999

This paper is to propose a concept and performance of the gravity engine which could extract energy from sea or river as a clean and renewable and sustainable power, the tidal or hydro-power. The vertical motion of the buoyancy cylinder of the present gravity engine is converted to the mechanical work directly without any hydraulic loss. The increased gravity potential during high tide is harnessed proportional to the length of the buoyancy cylinder times tidal height which is greater than the conventional tidal power using water mill. This energy amplification results from the net energy gain between the resource energy and the imposed energy to extract water out of the buoyancy cylinder. Its efficiency is higher than the conventional water mill due to its direct mechanical conversion.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.157-158
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• 2018

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 춘계학술논문요약집
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• pp.171-172
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• 2017

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 춘계학술논문요약집
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• pp.213-214
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• 2017

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.678-681
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• 2007

Now Korea depends upon the imported resources for about 97% of total using energy. So from October, 2001 Korean government has supported renewable energy business owners by providing them with Electric Power Industry Basis Fund. Only plant-use electricity of the small hydro power plant is exactly managed, but other renewable energy plants is unprepared or not yet managed. Therefore, in this paper, we'll analyze the plant-use electricity management of the small hydro power and propose improvement plans for plant-use electricity of the photovoltaic power plant.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.142-145
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• 2008

Electrical insulation of small hydro generator stator winding is one of the most important parts in generator facilities. Some stator winding insulation problems can be identified through analysis of insulation diagnostic test. So, Diagnosis of stator winding insulation is an important measure of ensuring the safe operation and extending the remaining life of small hydro generator. This paper presents case studies of insulation failure in generator stator windings and the results of insulation diagnostic test for small hydro generator stator windings. Especially, Conducting the insulation diagnostic test before the generator installed in site is very important process to keep the good insulation condition in service.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.778-780
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• 1997

This study considers a hydro power energy operation management and planning problem in KEPCO power systems for efficient use of hydro resources. A database is developed to provide with a convenience to hydro Power operation management and Planning by studying of the hydro resourse characteristics of Korea. The data is obtained in the operation history from 7 years ago and by considering the hydro facility planning to 2010 year. Also a computer program is developed to decide the monthly required volume of water and the water level of a dam in the Han river using the database.

• 신재생에너지
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• 제4권2호
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• pp.31-38
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• 2008

Using a surplus head in presented water supply pipes, we have studied to improve the operating efficiency of small hydro generator, which was chosen for a test model with 00 hydro power plant. With regard to power control and countermeasure of water hammer impact, Finally we have represented the optimal control method through the synthetical analysis of existing system symptoms, operation efficiency, the effect of water hammer impact and system configuration.