• International Journal of Ocean System Engineering
• /
• 제1권3호
• /
• pp.144-147
• /
• 2011

The rotor that initially converts the flow energy into rotational energy is a very important component that affects the efficiency of the entire tidal current power system. Rotor performance is determined by various design variables. Power generation is strongly dependent on the incoming flow velocity and the size of the rotor. To extract a large quantity of power, a tidal current farm is necessary with a multi-arrangement of devices in the ocean. However, the interactions between devices also contribute significantly to the total power capacity. Therefore, rotor performance, considering the interaction problems, needs to be investigated to maximize the power generation in a limited available area. The downstream rotor efficiency is affected by the wake produced from the upstream rotor. This paper introduces the performance of a downstream rotor affected by wakes from an upstream rotor, demonstrating the interference affecting various gabs between devices.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.315-316
• /
• 2008

On this paper, piezoelectric generators using piezoelectric ceramics were designed and fabricated. Generators were made by attaching cymbal type metal plates on upper and bottom sides of a disc type piezoelectric ceramic. Generator converts wasting mechanical energy to electrical energy. Output voltage was increased when thickness of ceramic and displacement of vibration were increased. Temperature of the ceramic was increased when it generates, but the temperature rising was saturated at certain temperature.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.727-729
• /
• 2005

Solar cell converts sunlight into the electricity that one of the most versatile forms of energy. It has been developed and applied on residental electric power system by urbanized countries as a alternative energy source to overcome energy problem after oil shock. This paper summarizes the results of these efforts by offering a snapshot of the configuration of photovoltaic in residential applications. The status of PV system components and inter -connection and safety equipment will be summarized. Hence this paper discusses only points that might be useful for application.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.720-722
• /
• 2005

A photovoltaic panel is a device that, through the photovoltaic effect, converts luminous energy into electric energy. Photovoltaic generation system uses infinity of solar energy, cost of fuel is needless and there is no all pollution or waste occurrence. This paper summarizes the results of these efforts by offering a photovoltaic system structure in 50kW large scale applications installed In Chosun University dormitory roof. The status of PV system components, are inter-connection and safety equipment monitoring system will be summarized as this article. This describes configuration of utility interactive photovoltaic system which generated power supply for dormitory In this paper represent 50kw utility PV system examination result

• 환경영향평가
• /
• 제13권4호
• /
• pp.213-222
• /
• 2004

Exergy is defined as the amount of work (entropy-free energy) a system can perform when it is brought into thermodynamic equilibrium with its environment. Exergy measures the distance from the inorganic soup in energy terms. Therefore, exergy can be considered as fuel for any system that converts energy and matter in a metabolic process. The aim of this study is to introduce structural dynamic modelling which is based on maximum exergy principle. Especially, almost ecological models couldn't explain algal succession until now. New model (structural dynamic model) is anticipated to predict or explain the succession theory. If the new concept using maximum exergy principle is used, algal succession can be explained in many actual cases. Therefore, It is estimated that structural dynamic model using maximum exergy principle might be a excellent tool to understand succession of nature from now on.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.337-339
• /
• 2005

A photovoltaic panel is a device that, through the photovoltaic effect, converts luminous energy into electric energy. Photovoltaic generation system uses infinity of sofa energy, cost of fuel is needless and there is no air pollution or waste occurrence. This paper summarizes the results of these efforts by offering a photovoltaic system structure in 50kW large scale applications installed in Chosun University dormitory roof and simulation tool. This describes configuration of utility interactive photovoltaic system which generated power supply for dormitory. In this Paper represent 50kW utility PV system examination result.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
• /
• pp.460-463
• /
• 2008

A large part of the overall industrial energy is dissipated as waste heat despite of much development in the utilization of thermal energy. A mean efficiency is reported to be only around 30 to 35%. The existing waste heat recovery technology has reached its limit and consequently, the development of a new technology is necessary. Improving efficiency using thermoelectric technology has recently come into the spotlight because of its unique way to recover thermal energy. In fact, thermoelectric generator directly converts thermal energy into electric energy by a solid state without any moving parts. Futhermore remarkable improvement in the thermoelectric energy conversion efficiency has been achieved. In this study, a thermoelectric generator was made using commercialized thermoelectric modules. With thermoelectric modules attached on a duct surface, hot air was blown into the duct using a hot air blower. On the other side of the module, a water jacket was attached to cool the module. With different air inlet temperatures and water flowrates, the electrical power of the thermoelectric generator was measured.

• 전력전자학회논문지
• /
• 제10권3호
• /
• pp.274-281
• /
• 2005

압전소자를 에너지원으로 사용하여 자립형 전기전자시스템에 에너지를 공급하는 에너지 획득(Harvesting) 개념의 구현을 위하여, 새로운 AC/DC 공진형 펄스 컨버터를 제안한다. 컨버터는 정류기와 DC 컨버터의 2단계로 구성되었으며, AC/DC 변환을 위한 정류기는 MOSFET의 3상한 동작 특성을 이용하여 구현하고, N형 및 P형 MOSFETs을 사용하여 DC/DC 부스트 컨버터를 구현하였다. 제안된 컨버터 시스템의 동작원리 및 동작모드를 스위칭 소자의 기생캐패시턴스를 고려하여 해석하고, 시뮬레이션을 통하여 해석결과를 검증하였다. CMOS IC 칩으로 제작된 본 시스템의 실험 결과는 수십 uW 용량에서 에너지 획득 개념의 구현 가능성을 제시하였다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제40권8호
• /
• pp.704-709
• /
• 2016

Wave energy generation systems can be divided into oscillating water chamber type, over topping device type and wave activating body type. The wave activating body type converts wave energy to kinetic energy, and the power generation amount increases as the motion of an activating body increases. In this paper, the wave energy convertor consists of a main body, which has an H-shape, and the activating body. These are connected by a bar-type bridge. By the incident wave, when the activating body moves with vertical motion this motion is consequently converted into rotational motion. The twisting moment and angular velocity at a shaft of convertor are calculated according to various conditions of the incident wave and the shape of the activating body. This can be used as a basic idea for determining the design of wave activating body type convertor.

• 한국추진공학회지
• /
• 제16권4호
• /
• pp.16-22
• /
• 2012

직경 22 mm 정도의 케이블 절단을 위한 케이블커터의 화약량 예측을 위하여 impact test machine을 이용한 낙하충격 시험을 실시하였다. Impact test 시험 결과는 Probit 방법으로 분석하였으며, 99% 신뢰도에서 99.99% 절단하는 에너지는 37.7 J로, 절단 평균 에너지는 24.9 J로 예측 되었다. 150 mg의 ZPP를 사용하여 시험한 결과, 케이블이 3번 모두 절단되었다. 이때 측정된 압력으로부터 계산된 에너지는 26.1 J이었으며 이 값은 impact 시험 결과나 화약에너지의 10%가 기계적 에너지로 변화된다는 가정 하에 ZPP 150 mg이 발생하는 기계적 에너지인 24.5 J과 아주 유사하다. Impact test의 분석결과를 적용하면 ZPP 230 mg의 화약으로 99% 신뢰도에서 99.99% 절단 확률을 보장할 수 있을 것으로 판단된다.