Low-power autonomous wave energy capture device for remote sensing and communications applications

Symonds, Deanelle T.; Davis, Edward P.; Ertekin, R. Cengiz

doi:10.1109/ecce.2010.5617902

Cited by 11 publications

(11 citation statements)

References 10 publications

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“…Therefore, the displacement amplitude of the relative motion between the buoy and the internal mass should not be too large, resulting in the fact that advanced control methods may lose their advantages. Resistive control, though less efficient than others, may be a good alternative due to its simplicity, robustness, and unidirectional energy flow, and has been widely used for point absorbers [8,20]. In this paper, resistive control is employed in the power absorption of point absorbers, and the PTO system is modeled as a spring-damper system with the control force defined by…”

Section: Power Absorption In Surgementioning

confidence: 99%

“…However, the above conclusion is based on the idealized assumption that only one degree of freedom is employed to absorb wave power with others manually fixed. In practical applications, since point absorbers are normally moored at a single point [17][18][19][20], wave compliance of the buoy will make the above assumption unsatisfiable. For example, if surge is employed to absorb power, the buoy will inevitably oscillate in pitch.…”

Section: Introductionmentioning

confidence: 99%

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On Power-Absorption Degrees of Freedom for Point Absorber Wave Energy Converters

2020

JMSE

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Point absorbers are extensively employed in wave energy conversion. In this work, we studied the point absorber with the buoy of a vertical cylindrical shape. Wave power absorption is obtained through the relative motion between the buoy and an internal mass. Three power-absorption degrees of freedom are investigated, i.e., surge, heave, and pitch, together with the influence of wave compliance of the buoy. Results show that, to absorb more power, the internal mass should be as large as possible for power absorption in translational degrees of freedom, i.e., surge and heave. The total rotational inertia should be as large as possible and the center of mass should be as low as possible for power absorption in pitch. Wave compliance of the buoy slightly enhances the power absorption in surge, but significantly weakens the power absorption in pitch. Surge is the best degree of freedom for power absorption owing to the highest efficiency, indicated by the largest capture width ratio. The simple resistive control is found to be adequate for wave power absorption of the self-reacting point absorber.

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Section: Power Absorption In Surgementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On Power-Absorption Degrees of Freedom for Point Absorber Wave Energy Converters

2020

JMSE

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“…The body's motion is updated with the value of s(1) and d(1) and the forces are computed again with the updated values to calculate s(2) and d (2). This is repeated to get s(3), s(4), d (3), and d (4). The body's motions for the next time step are obtained with Eq.…”

Section: Time Integrationmentioning

confidence: 99%

“…Symonds et al 3 pointed out that the acoustic sensors draw between 100 and 200 W of continuous power, which greatly limits the battery life of the buoy to 12-24 hours. Recharging a drained sensor battery is so unreasonable and expensive that many buoys are intended to sink to the bottom after their brief period of operation.…”

Section: Introductionmentioning

confidence: 99%

Wave power calculations for a wave energy conversion device connected to a drogue

Nolte

Ertekin

2014

Journal of Renewable and Sustainable Energy

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We present the numerical modeling of a heaving, point-source wave energy conversion (WEC) device, previously tested by the University of Hawaii at Manoa. The WEC device converts the vertical heave displacements into a rotational motion to generate electrical power; the heave displacements converted are from the WEC system rising with the incoming waves relative to an anchoring system. Two anchoring methods of the WEC device are referred to as the single-body case (moored system) and double-body case (drogue anchored system). The numerical model performs hydrodynamic analysis in the time domain in irregular seas for the single-body or double-body case. We then compare the predictions with the available in-ocean experiments. The computer program written for this purpose solves for the individual body motion and predicts the WEC device's power production over the time series. Moreover, we present the results of the study that shows the effect of the device-damping characteristics and the size and the depth of operation of the drogue on wave-power predictions. V C 2014 AIP Publishing LLC.

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“…Fewer investigations have focused on mobile WEC platforms for low-power applications. Portable WECs using directly driven PTO based on proprietary transmissions with rotary generators [13][14][15] and linear electromagnetic induction [16][17][18][19] have been recently explored. In these studies, average power generation spanning around 0.01-100 W has been numerically and experimentally demonstrated.…”

Section: Introductionmentioning

confidence: 99%

Multistable chain for ocean wave vibration energy harvesting

2014

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The heaving of ocean waves is a largely untapped, renewable kinetic energy resource. Conversion of this energy into electrical power could integrate with solar technologies to provide for round-the-clock, portable, and mobile energy supplies usable in a wide variety of marine environments. However, the direct drive conversion methodology of gridintegrated wave energy converters does not efficiently scale down to smaller, portable architectures. This research develops an alternative power conversion approach to harness the extraordinarily large heaving displacements and long oscillation periods as an excitation source for an extendible vibration energy harvesting chain. Building upon related research findings and engineering insights, the proposed system joins together a series of dynamic cells through bistable interfaces. Individual impulse events are generated as the inertial mass of each cell is pulled across a region of negative stiffness to induce local snap through dynamics; the oscillating magnetic inertial mass then generates current in a coil which is connected to energy harvesting circuitry. It is shown that linking the cells into a chain transmits impulses through the system leading to cascades of vibration and enhancement of electrical energy conversion from each impulse event. This paper describes the development of the multistable chain and ways in which realistic design challenges were addressed. Numerical modeling and corresponding experiments demonstrate the response of the chain due to slow and large amplitude input motion. Lastly, experimental studies give evidence that energy conversion efficiency of the chain for wave energy conversion is much higher than using an equal number of cells without connections.

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Low-power autonomous wave energy capture device for remote sensing and communications applications

Cited by 11 publications

References 10 publications

On Power-Absorption Degrees of Freedom for Point Absorber Wave Energy Converters

On Power-Absorption Degrees of Freedom for Point Absorber Wave Energy Converters

Wave power calculations for a wave energy conversion device connected to a drogue

Multistable chain for ocean wave vibration energy harvesting

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