• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.111-112
• /
• 2015

최근 에너지 문제가 많은 이슈로 떠으르면서 자연으로부터 에너지를 얻는 신재생 에너지에 대한 관심도 높아지면서 많은 연구가 이루어지고 있다. 그중에서도 파력 발전은 파도의 에너지를 이용해 부이의 움직임을 파력 PCS(Power Conditioning System)가 제어하여 발전을 이루는 방식이다. 파도의 움직임에 따라 부이의 운동이 선형발전기를 통해 에너지를 얻을 수 있다. 하지만 파도의 모델은 규칙적인 정현파가 아니고 주기나 속도의 움직임이 일정하지 않다는 특성을 가지고 있다. 이러한 파도의 움직임을 잘 모사하는 것이 파력 발전 제어 전략 수립에 있어서 매우 중요하다. 본 논문에서는 이러한 파도의 움직임을 모사하기 위한 시뮬레이터를 구현하였다. 선형발전기 대신 원형의 영구자석 전동기를 이용해 파도의 움직임을 구현하였다. 시뮬레이션 및 실험을 통해 그 타당성을 검증하였다.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.6
• /
• pp.780-787
• /
• 2012

In general, the ocean wave vibration power generator consists of buoy, vibration system and linear generation system. It maximized energy efficiency by using resonance phenomenon that turned to the natural frequency of vibration system and frequency of ocean wave energy. But it is difficult to obtain efficiently energy from ocean wave because the frequency of ocean wave changes from moment to moment. In this paper, we study the buoy and vibration system of ocean wave power generator to solve these problem. Firstly, we designed the buoy that gives rise to resonance between ocean wave and buoy. Secondly, we designed vibration system that is occurred to resonance between buoy and vibration system. And then the relative velocity between the buoy and magnetic of ocean wave vibration generator increases and the relative displacement between buoy and ocean wave decreases at the same time. As a result, the method which is proposed in this paper has merits not only securing its stability from harsh ocean wave environment but also obtaining more kinetic energy from ever-changing ocean wave.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.6
• /
• pp.596-602
• /
• 2013

In general, existed vibration energy harvester is optimum in electronic energy gleaned from vibration energy with fixed single frequency, because it is using resonance. But it is limit in electronic energy gleaned from ocean wave energy with variant frequency. This paper studied for width band vibration energy harvester that obtains electronic energy from ocean wave with infinite vibration energy in order to solve it. It is composed of buoy to occur resonance in the center frequency of ocean wave energy and the vibration system to occur resonance in the same frequency. As a result, existed vibration energy harvester using resonance maximized electronic energy conversion efficiency in single frequency, while proposed width band vibration energy harvester has merit that maximized electronic energy conversion efficiency in ocean wave with variant frequency.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2018.11a
• /
• pp.147-149
• /
• 2018

파력발전은 파도의 운동에너지와 위치에너지를 전기에너지로 변환하는 발전 방식을 사용하여 무한한 에너지원으로 친환경적이다. 기존에 있는 파력발전기는 대체적으로 큰 전기에너지를 생산하며 이 에너지를 이용하기 위해서는 큰 시설물과 대형 발전기 등이 중심이 되어있다. 항로표지와 같은 해양안전유도시설은 비교적 큰 에너지 보다는 적은 에너지원을 필요로 하기에 기존의 파력에너지와의 접근이 용이하지 않는다. 별도의 시설물 없이 작은 파도에서도 위치의 변화에 따라 전기에너지를 생산하는 방식의 Motion Generator를 연구하였다.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.4 no.4
• /
• pp.3-11
• /
• 2001

To know the seawater infiltration into tidal flat sediment in coastal area is very important, because it is significantly correlated with the infiltration and transportation of pollutants in soil, the supply of dissolved oxygen, nutrients and organic matter to benthic organisms for survival of benthic organisms and the seawater purification. So, we set up purpose to clarify the infiltration behavior of seawater by wave action in tidal flat, to clear the effects of slope of tidal flat and breaking wave height on seawater infiltration and to quantify the infiltration volume of seawater. For purpose, the seawater infiltration was studied with visualization method by using coloring tracer and transparent glass beads replaced as natural sediment in model tidal flat. Specific conclusions derived from this study are as follows. The semi-circular type infiltration of seawater by wave action into saturated sediment was a new infiltration behavior that was not considered in previous studies. The infiltration rate of seawater was increased with increasing of breaking wave height and slope of tidal flat. However, the effects of the slope was bigger than that of breaking wave height on seawater infiltration into tidal flat sediments. It was possible to calculate the infiltration volume of seawater by wave action in natural tidal flat sediment and in fields. Therefore, we can point out that wave action play an important role in the supply of dissolved oxygen, nutrients and organic matter to benthic organisms, transportation or diffusion of pollutants and seawater purification. So, we hope to be studied the supply of food to benthic organism, pollutant transport and seawater purification on the base of these results.

• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.8
• /
• pp.1028-1034
• /
• 2011

This paper have been studied that ocean wave power vibration generation system with two D.O.F.(degree of freedom) consists of buoy and vibration generation system with two D.O.F. for using efficiency of ocean wave energy. It selected main frequencies ${\omega}_1$, ${\omega}_2$ in frequency with ocean wave and it fitted them to the natural frequencies of vibration system with two D.O.F. in the vibrational power generation system. Then each the relative velocity of between the winding coil and the permanent magnet is faster than the velocity of ocean wave up and down motion by resonance phenomenon. Also the ocean wave power generation with two D.O.F. obtained the more electric energy then the ocean wave power generation with one D.O.F. by coupling effect for two D.O.F. vibration system. Therefore ocean wave power vibration generation system with two degree of freedom that is proposed in this paper has merits which not only using more energy in the ocean wave but also obtaining more electronic energy.

• Proceedings of the KIPE Conference
• /
• 2014.11a
• /
• pp.93-94
• /
• 2014

본 논문의 주제는 가파도 마이크로 그리드에 적용한 1MVA급 배터리 에너지 저장시스템(BESS-Battery Energy Storage System)을 소개하는 것이다. 에너지 저장장치가 디젤발전기와의 연계 및 독립운전 하여 탄소 배출 없이(Carbon-Free) 가파도 전체 부하에 전원을 공급하는 실증 사례를 살핀다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2019.05a
• /
• pp.51-52
• /
• 2019

In the past, waves, which are the main external forces acting on marine and coastal structures, have been dealt with only in terms of safety. Recently, various studies have been conducted to define the characteristics of waves in a specific area in order to respond to the increasing demand for diversified marine activities such as ocean energy development and marine leisure sports. Although the characteristics of waves are specific to the site, the available spectrum model proposed in previous studies are limited. In this study, we analyzed the shape of the ocean wave spectrum by comparing it with the standard spectrum model.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2001.10a
• /
• pp.150-155
• /
• 2001

단일 소파막에 대한 파도 반사문제와 투과. 또 이중으로 설치된 소파막에 대한 반사와 투과문제에 대한 양함수 해를 도출하였다. 단일 막에 대한 파도의 반사가 에어리 파의 해당 벽에 의해서만 입자반사로서 일어난다고 보고 이를 원거리 파도에너지와 일치시켜 반사 파고를 얻었다. 이중 막에 대해서는 각각의 파도가 독립적으로 단일 막에 의해서 반사 또는 투과가 되고 이들이 중첩되어 전체 파고가 형성되어지는 것으로 간주하여 전체 반사계수와 투과계수를 결정하였다. 단일 막에 대한 투과계수의 결과는 정성적으로 다른 계산결과와 비슷한 경향을 보이며, 실험결과보다는 높게 예측되었다. 이중 단일 막에 대한 결과는 낮은 주파수에서 실험결과와 유사한 경향을 보이고, 중간 주파수에서 완만한 감소를 보였다. 계산이 양함수 해로 얻어지므로 개념설계와 현장에서 유용하게 활용될 수 있으리라 기대된다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.6
• /
• pp.615-620
• /
• 2013

There is considerable interest in developing energy sources capable of larger power densities. In our previous works, we proved that by coupling an exothermic chemical reaction with 1D nanostructures, a self-propagating reactive wave can be driven along its length with a concomitant electrical pulse of high specific power, which we identified as a thermopower wave. Herein, we discuss details about many different aspects of a thermopower wave. Different alignment degree in vertically aligned CNT films is evaluated in the reactive wave speed and correlated with its thermal reaction that affects the change in the magnitude of energy generation. The effects of the temperature-dependent properties of chemical fuels and CNTs are evaluated. Furthermore, we explore the convection and radiation portions in this thermal wave as well as the synchronization between the thermal reaction transfer and the oscillation of the electrical signal.