• Journal of Advanced Marine Engineering and Technology
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• 제35권8호
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• pp.1028-1034
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• 2011

본 논문에서는 파도의 상하운동에너지의 이용효율을 높이기 위해서 부양체와 2 D.O.F.(자유도) 진동발전시스템을 일체로 구성한 파력진동발전시스템을 제안한다. 파도가 갖는 상하운동 주파수 중 속도 에너지가 큰 주요 주파수 ${\omega}_1$, ${\omega}_2$을 선정하고, 2 D.O.F. 파력진동발전시스템의 고유진동수와 선정된 주파수들을 일치시킨다. 그러면 공진효과에 의해 각각의 질량과 권선사이의 상대속도가 파도의 상하운동속도보다 커진다. 또한 2 D.O.F. 진동시스템의 연성효과로 인한 1 D.O.F. 파력진동발전시스템보다 더 많은 전기에너지를 얻을 수 있다. 따라서 본 논문에서 제안한 2 D.O.F. 파력 발전시스템은 파도가 갖는 에너지를 더 많이 이용할 뿐만 아니라 더 많은 전기에너지를 얻을 수 있는 장점을 가짐을 알 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• 제35권6호
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• pp.861-866
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• 2011

본 논문에서는 파도의 상하운동에 의해 발전되는 형발전시스템과 진동발전시스템이 결합된 하이브리드 발전방법을 제안한다. 선형발전시스템은 권선과 영구자석으로 구성되어있고, 파도의 상하운동속도를 직접적으로 사용하므로 파도의 주파수에 관계없이 안정적인 발전을 한다. 그리고 진동발전시스템은 진동시스템인 영구자석, 스프링과 발전시스템인 영구자석, 권선으로 구성되어 있다. 진동발전시스템은 파도의 주파수와 진동시스템의 고유진동수를 일치시킨 공진대역에서 구동함으로써 파도의 상하운동 속도보다 더 큰 속도를 이용하여 더 많은 전기에너지를 얻을 수 있다. 따라서 본 연구에서 제안한 하이브리드 파력발전방법은 공진영역에서 더 많은 전기에너지를 얻을 수 있을 뿐만 아니라 공진영역을 벗어난 대역에서도 안정적으로 발전할 수 있는 장점을 가짐을 알 수 있다.

• 대한기계학회논문집A
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• 제28권6호
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• pp.717-725
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• 2004

A power generation systems are proposed to convert ambient mechanical vibration into electrical energy using cantilever-type piezoelectric materials. The vibration-based power device can be used for self-powered systems without batteries. This paper presents the theoretical analysis for the coupled equations of piezoelectric and structural motions and investigates the dynamic characteristics of the self-power system using transfer function method. The theoretical model is verified by the finite element analysis of the resonance frequency, the dynamic response of the structure and the sensor sensibility. Experimental results measured using a prototype system agree with the theoretical predictions. The system is shown to produce 34.5 ㎼ in average. Finally, we perform the optimal design for system variables to maximize output power.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.1059-1066
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• 2003

A power generation system are proposed to convert ambient mechanical vibration into electrical energy using cantilever-type piezoelectric materials. The vibration-based power device can be used for self-powered systems without batteries. This paper presents the theoretical analysis for the coupled equations of piezoelectric and structural motions and investigates the dynamic characteristics of the self-power system using transfer function method. The theoretical model is verified by the finite element analysis of the resonance frequency, the dynamic response of the structure and the sensor sensibility. Experimental results measured using a prototype system agrees with the theoretical predictions. The system is shown to produce 2.53㎼ in average. Finally, we perform the optimal design for system variables to maximize output power.

• 한국도로학회논문집
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• 제12권4호
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• pp.121-129
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• 2010

본 논문에서는 차량주행 시 교량에서 발생하는 진동에너지를 사회기반시설에 활용 가능한 전기에너지로 변환하는 진동력 발전시스템의 기초개념에 대해 연구하였다. 이 논문은 자기유도기술개념의 교량 진동력 발전 시스템에 대한 개념을 정립하고, 교량의 진동에너지를 전기에너지로 변환하는 진동력 발전장치를 제안하였다. 또한, 진동력 발전의 실 교량 적용성을 검토하기 위하여 제안한 진동력 발전장치를 용인신봉구역에 최근 건설된 차도교량에 직접 설치하여 실험함으로써, 본 논문에서 제안된 진동력 발전 장치의 발전성능과 교량의 상시진동을 이용한 진동력 발전의 적용 가능성을 확인하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3365-3370
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• 2007

We developed micro power generation system using piezoelectric materials. In our system, the ambient vibrating energy is converting to electric energy by deflection of piezoelectric beams. The system consists of energy generating parts, converting enhancement parts, electric regulation and charging parts, and interface with small-energy-consuming mobile devices. The geometry of piezoelectric beams, the source of vibrating energy, and the electric load of target application determine the characteristics of generating electric power, such as impedance, voltage, current and power density. Therefore, we made a model for analysis of generating power with given information such as piezoelectric materials, geometry, vibration type, and mass. With this model, we can calculate capacitance of piezoelectric beams, generating voltage, current, and power. To obtain maximum energy transfer efficiency, we approached this study in the view of material, electrical, and mechanical engineering

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
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• pp.75-75
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• 2011

This paper has been studied that ocean wave vibration power generator is composed of buoy and vibration generator to make effective use of ocean wave energy. We designed buoy to can occur resonance for dominant frequency with ocean wave. And then we fitted the natural frequency of vibration system with vibration power generator to buoy's natural frequency. And we can show that the amplitude of ocean wave up and down motion is decreased, on the other hand, the displacement of vibration system with vibration power generator is increased. Therefore, ocean wave vibration power generator which is proposed in this paper has merits not only securing its stability from surroundings but also producing more electronic power by using ocean wave energy.

• 한국소음진동공학회논문집
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• 제25권6호
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• pp.406-413
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• 2015

The piezoelectric coupling in piezoelectric vibration energy harvesters with load resistance induces electrical damping as well as increase in the system stiffness. Starting from analytically deriving the explicit relations through governing equations in the frequency domain, this work identifies the characteristics of the electrically induced damping mechanism and shows that the electrically induced damping serves as a structural hysteretic damping on condition that a piezoelectric vibration energy harvester is excited at its short-circuit resonant frequency and its load resistor is optimally impedance- matched at the same time. Finally, it is analytically verified that the equivalence of a mechanical and an electrically induced damping ratio is required for the maximum power generation at a load resistor, which was claimed in some literature.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.565-567
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• 2009

• 동력기계공학회지
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• 제17권3호
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• pp.23-27
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• 2013

In this research paper, we study on how to decrease the high vibration of turbine hood casings which are main facilities of power generation industry. Cause of Standard coal-fired power 500MW facilities turbine hoods' high vibration is that Natural frequency of hood casing designed in near domain frequency, when they are making hoods. We investigate to reduce high vibration at hood casing. We use FEM method to found how to avoid resonance, and test to confirm that our FEM result. We Finally attach minium mass plate at hood casing to avoid resonance and high vibration reduce lower $100{\mu}m$.