• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.433-434
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• 2016

전력계통은 안정된 전압과 주파수의 전력수급이 요구되는 가운데 발전기의 안정성은 주요 요소이다. 그런데 수차발전기 운전 중 부하 탈락 시 급격한 주파수 상승에 의한 발전기 과전압발생은 발전기 여자시스템의 제어신호인 전압실효값 오차에 기인한 것이다. 이런 오차를 최소화하고 발전기 전압을 안정시키기 위해 ZCP(Zero Crossing Point)와 FPGA를 이용한 주파수 검출영역 확장과 DFT(Discrete Fourier Transform) 알고리즘을 이용하여 안정된 전압실효값을 계산하는 기법을 설계하였다. 실험결과, 기존 57~63Hz 주파수 영역의 DFT 대비 확장된 30~90Hz 대역의 전압실효값 오차는 최대 24.68%에서 0.22%로 대폭 개선되었다.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.452-455
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• 2005

We have studied the prearranged plan and the economy of a candidate site for the development of small hydro power. And also we have confirmed its economy by suggesting the technology of the unmanned operation and the selection of the water turbine generator which has a great efficiency. working rate and suitability to the topographical characteristics of various development sites, for example, irrigation reservoirs, water works pipes, sewage systems and cool ing water of a steam power stat ion. Besides we give more examples of the select ion of Francis, propeller turbine and induction generator which can achieve a maximum of power production at a minimum construction cost. With a water turbine which runs at the low head we are able to suggest many programs to boost a development of small hydro power more economically.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.248-252
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• 2007

As Waterpower Generation generates electricity using the difference of altitude of water, also let the turbine revolves through water pipe, at this time the revolving turbine causes exceedingly huge noise. Accordingly, not only those workers in the hydraulic turbine dynamo room are suffering the difficulties in mutual communication, but also those workers in the adjacent office are enduring the obstruction to the business due to the noise. Therefore, this Study has analyzed the reduction effect on the noise of hydraulic turbine dynamo room utilizing computer simulation, through the preceding research with the optimized model for architectural acoustic factor of the hydraulic turbine dynamo room. It is considered that such research result could be applied as the useful material for improvement of acoustic performance and noise-reduction effect at other similar hydraulic turbine dynamo room in the future.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.273-277
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• 2007

In case of the Hydraulic Turbine Dynamo operating for Waterpower Generation, it makes very huge and loud noises, and it influences bad effect physically as same as mentally to those people who are working inside of power plant, and brings the decline of an effective working efficiency. However, its evaluation method or measure about such noise reflects merely its physical attribute which is sensuous Loudness of the Noise itself, since the accumulation effect of Noise or the meaning connected with psychological response did not reflect, it is the actual state that a rational evaluation is unable to expect. Consequently, this Study has attempted to evaluate the Noise of Hydraulic Turbine Dynamo by analyzing the sound quality using Zwicker‘s Psychological Acoustic Parameter, after classification by its positions of the Noise occurring at Hydraulic Turbine Dynamo.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.776-777
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• 2011

조속기는 수차발전기의 핵심을 담당하는 두뇌라고 말할 수 있으며, 전력계통의 부하(주파수)가 변할 경우 수차발전기의 회전속도를 정격으로 유지시켜 양질의 전기를 생산하도록 항시 조정되는 역할을 한다. 최근 조속기는 디지털화되어 최적제어 감시 및 보호기능을 수행하고 있으나 문제점도 하나둘씩 나타나고 있는 실정이다. 본 논문에서는 디지털 가버너의 Isolation Mode에 대한 설명과 사고사례를 통해 디지털가버너 운영 시 문제점을 분석, 검토하여 보완하고자 하였으며, 이를 통해 안정적으로 전력공급을 주요 목적으로 하였다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1344-1345
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• 2011

경북 군위군 고로면에 위치한 저수용량 48,000천톤의 군위 다목적댐에 설치된 소수력발전기에 대한 설치공사 중 수차 설계도면 해석오류에 의한 Guide Vane(이하 G/V로 함.) 과다개방으로 인한 설비고장 및 개선사례, 년 중 댐 수위 변동을 감안한 정격수위와 저수위 시의 수차효율 시험을 통한 댐 수위별 최적의 발전설비 운영방안을 검토하여 저탄소 녹색에너지원인 군위다목적댐 소수력의 발전수익 증대를 도모하였다.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.121-128
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• 1998

In this paper, We researched the optical performance of eye by means of the Gullstrand EYE MODEL. And we also researched the glasses that are made by designing the eye glasses corrected with the Astigmatism and the optical performance of the glasses in the optical system which are compounded with eyes. This paper can be used as a reference material in designing the glasses for ametropic correction.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.5
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• pp.1087-1095
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• 1994

Chain drive power transmission system was developed for a low head hydro-turbine which generates power by energy transformation on the turbine blades attached to chains. Also, experimental and theoretical analysis for the sprocket wheel tooth load distribution were performed. The tooth load was measured by the specially designed load sensor. It was found that the tooth load distribution for the steady state operation was in good accordance with the quasi-static state results showing the peak load at the final meshing tooth. The trend of the experimental results agreed with the theoretical results based on the spring model analysis and difference in the magnitude of the maximum tooth load was considered to be the effect of the variable spring constant due to the moving contact point between the roller and sprocket wheel tooth.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.664-667
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• 2009

The Francis type hydro turbine with vertical axis has been designed and analized for hydraulic performance verification. The guide vane angle of turbine casing were designed to be varied according to the condition of head and flowrate. When the changes in flowrate and output were comparatively large, the efficiency drop were small, so the efficiency characteristics and stability of the entire operating condition were maintained in good condition. These results showed that the developed hydro turbine in this study will be suitable for small hydro power stations with medium and high head such as agricultural reservoirs and large dam.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.660-663
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• 2009

Currently in Korea, the lack of facilities and technical criteria for the performance test of small hydropower degrades the efficiency of the domestic small hydropower turbine, and makes it difficult to objectively evaluate the performance of hydro turbine. Therefore Korean institute of water and environment in K-water planned making a basis of performance test of small hydropower by using our flowmeter calibration system the largest one in Korea. We planned the maximum measurable power of hydro turbine will be 200 kW in our system. Improving the efficiency of small hydropower system can achieve the additional development benefit about 1.5 billion won per year.