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公开(公告)号:US20180163690A1
公开(公告)日:2018-06-14
申请号:US15837853
申请日:2017-12-11
申请人: Ossama Abdelkhalik , Shangyan Zou , Rush D. Robinett, III , National Technology & Engineering Solutions of Sandia, LLC
发明人: Ossama Abdelkhalik , Giorgio Bacelli , Shangyan Zou , Rush D. Robinett, III , David G. Wilson , Ryan G. Coe
CPC分类号: F03B13/183 , F03B13/16 , F03B15/00 , F03B15/20 , F05B2250/43 , F05B2270/20 , G02F1/39 , G06F1/02 , G06F1/022 , H01J49/4275 , Y02E10/38
摘要: The invention provides optimal control of a three-degree-of-freedom wave energy converter using a pseudo-spectral control method. The three modes are the heave, pitch and surge. A dynamic model is characterized by a coupling between the pitch and surge modes, while the heave is decoupled. The heave, however, excites the pitch motion through nonlinear parametric excitation in the pitch mode. The invention can use a Fourier series as basis functions to approximate the states and the control. For the parametric excited case, a sequential quadratic programming approach can be implemented to numerically solve for the optimal control. The numerical results show that the harvested energy from three modes is greater than three times the harvested energy from the heave mode alone. Moreover, the harvested energy using a control that accounts for the parametric excitation is significantly higher than the energy harvested when neglecting this nonlinear parametric excitation term.
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2.
公开(公告)号:US20180163691A1
公开(公告)日:2018-06-14
申请号:US15837885
申请日:2017-12-11
申请人: Ossama Abdelkhalik , Rush D. Robinett, III , Shangyan Zou , Umesh Korde , National Technology & Engineering Solutions of Sandia, LLC
发明人: Ossama Abdelkhalik , Rush D. Robinett, III , Shangyan Zou , David G. Wilson , Giorgio Bacelli , Umesh Korde , Ryan G. Coe
CPC分类号: F03B13/183 , F03B13/16 , F03B15/00 , F05B2250/43 , F05B2270/20 , G06F1/02 , G06F1/022 , Y02E10/38
摘要: A parametric excitation dynamic model is used for a three degrees-of-freedom (3-DOF) wave energy converter. Since the heave motion is uncoupled from the pitch and surge modes, the pitch-surge equations of motion can be treated as a linear time varying system, or a linear system with parametric excitation. In such case the parametric exciting frequency can be tuned to twice the natural frequency of the system for higher energy harvesting. A parametric excited 3-DOF wave energy converter can harvest more power, for both regular and irregular waves, compared to the linear 3-DOF. For example, in a Bretschneider wave, the harvested energy in the three modes is about 3.8 times the energy harvested in the heave mode alone; while the same device produces about 3.1 times the heave mode energy when using a linear 3-DOF model.
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公开(公告)号:US10344736B2
公开(公告)日:2019-07-09
申请号:US15837853
申请日:2017-12-11
发明人: Ossama Abdelkhalik , Giorgio Bacelli , Shangyan Zou , Rush D. Robinett, III , David G. Wilson , Ryan G. Coe
IPC分类号: F03B13/10 , F03B13/12 , F03B13/18 , F03B15/20 , G02F1/39 , G06F1/02 , H01J49/42 , F03B13/16 , F03B15/00
摘要: The invention provides optimal control of a three-degree-of-freedom wave energy converter using a pseudo-spectral control method. The three modes are the heave, pitch and surge. A dynamic model is characterized by a coupling between the pitch and surge modes, while the heave is decoupled. The heave, however, excites the pitch motion through nonlinear parametric excitation in the pitch mode. The invention can use a Fourier series as basis functions to approximate the states and the control. For the parametric excited case, a sequential quadratic programming approach can be implemented to numerically solve for the optimal control. The numerical results show that the harvested energy from three modes is greater than three times the harvested energy from the heave mode alone. Moreover, the harvested energy using a control that accounts for the parametric excitation is significantly higher than the energy harvested when neglecting this nonlinear parametric excitation term.
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公开(公告)号:US12129820B1
公开(公告)日:2024-10-29
申请号:US17949818
申请日:2022-09-21
发明人: Umesh Korde , Ryan G. Coe , Giorgio Bacelli
IPC分类号: F03B13/14
CPC分类号: F03B13/14 , F03B13/142
摘要: A tubular wave energy converter configured to remain afloat near the surface of a wave field and trap a water column oscillating asymmetrically to the wave field in which the converter is located. Water column oscillations create a pressure flux providing motive power for a generator. The converter, generator and a powered payload making up an autonomous wave powered device are packaged to fit within and be deployed by a torpedo launcher. The autonomous device may be deployed above or beneath the surface. Device buoyant characteristics are configured to maintain the device afloat and self-righting toward an upright oriented for operation in the wave field.
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公开(公告)号:US11703027B1
公开(公告)日:2023-07-18
申请号:US17866083
申请日:2022-07-15
摘要: Systems and methods for a WEC controller that uses a self-tuning proportional-integral control law prescribing motor torques to maximize electrical power generation and automatically tune the controller to maximize power absorption. In an embodiment, the controller may be part of any resonant WEC system. The control law relies upon an identified model of device intrinsic impedance to generate a frequency-domain estimate of the wave-induced excitation force and measurements of device velocities. The control law was tested in irregular sea-states that evolved over hours (a rapid, but realistic time-scale) and that changed instantly (an unrealistic scenario to evaluate controller response).
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6.
公开(公告)号:US10415537B2
公开(公告)日:2019-09-17
申请号:US15837885
申请日:2017-12-11
申请人: National Technology & Engineering Solutions of Sandia, LLC , Michigan Technological University , South Dakota Board of Regents
发明人: Ossama Abdelkhalik , Rush D. Robinett, III , Shangyan Zou , David G. Wilson , Giorgio Bacelli , Umesh Korde , Ryan G. Coe
摘要: A parametric excitation dynamic model is used for a three degrees-of-freedom (3-DOF) wave energy converter. Since the heave motion is uncoupled from the pitch and surge modes, the pitch-surge equations of motion can be treated as a linear time varying system, or a linear system with parametric excitation. In such case the parametric exciting frequency can be tuned to twice the natural frequency of the system for higher energy harvesting. A parametric excited 3-DOF wave energy converter can harvest more power, for both regular and irregular waves, compared to the linear 3-DOF. For example, in a Bretschneider wave, the harvested energy in the three modes is about 3.8 times the energy harvested in the heave mode alone; while the same device produces about 3.1 times the heave mode energy when using a linear 3-DOF model.
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