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Multi-Resonant Feedback Control Of Multiple Degree-Of-Freedom Wave Energy Converters, Ossama Abdelkhalik, Shangyan Zou, Rush D. Robinett Iii, David G. Wilson, Giorgio Bacelli, Ryan G. Coe, Umesh Korde
Multi-Resonant Feedback Control Of Multiple Degree-Of-Freedom Wave Energy Converters, Ossama Abdelkhalik, Shangyan Zou, Rush D. Robinett Iii, David G. Wilson, Giorgio Bacelli, Ryan G. Coe, Umesh Korde
Michigan Tech Patents
Multi-resonant control of a 3 degree-of-freedom (heave-pitch-surge) wave energy converter enables energy capture that can be in the order of three times the energy capture of a heave-only wave energy converter. The invention uses a time domain feedback control strategy that is optimal based on the criteria of complex conjugate control. The multi-resonant control can also be used to shift the harvested energy from one of the coupled modes to another, enabling the elimination of one of the actuators otherwise required in a 3 degree-of-freedom wave energy converter. This feedback control strategy does not require wave prediction; it only requires …
Multi-Resonant Feedback Control Of A Single Degree-Of-Freedom Wave Energy Converter, David G. Wilson, Rush D. Robinett Iii, Ossama Abdelkhalik, Jiajun Song, Giorgio Bacelli
Multi-Resonant Feedback Control Of A Single Degree-Of-Freedom Wave Energy Converter, David G. Wilson, Rush D. Robinett Iii, Ossama Abdelkhalik, Jiajun Song, Giorgio Bacelli
Michigan Tech Patents
A multi-resonant wide band controller decomposes the wave energy converter control problem into sub-problems; an independent single-frequency controller is used for each sub-problem. Thus, each sub-problem controller can be optimized independently. The feedback control enables actual time-domain realization of multi-frequency complex conjugate control. The feedback strategy requires only measurements of the buoy position and velocity. No knowledge of excitation force, wave measurements, nor wave prediction is needed. As an example, the feedback signal processing can be carried out using Fast Fourier Transform with Hanning windows and optimization of amplitudes and phases. Given that the output signal is decomposed into individual …
Model Predictive Control Of Parametric Excited Pitch-Surge Modes In Wave Energy Converters, Ossama Abdelkhalik, Rush D. Robinett Iii, Shangyan Zou, David G. Wilson, Giorgio Bacelli, Umesh Korde, Ryan G. Coe
Model Predictive Control Of Parametric Excited Pitch-Surge Modes In Wave Energy Converters, Ossama Abdelkhalik, Rush D. Robinett Iii, Shangyan Zou, David G. Wilson, Giorgio Bacelli, Umesh Korde, Ryan G. Coe
Michigan Tech Patents
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 …
Pseudo-Spectral Method To Control Three-Degree-Of-Freedom Wave Energy Converters, Ossama Abdelkhalik, Giorgio Bacelli, Shangyan Zou, Rush D. Robinett Iii, David G. Wilson, Ryan G. Coe
Pseudo-Spectral Method To Control Three-Degree-Of-Freedom Wave Energy Converters, Ossama Abdelkhalik, Giorgio Bacelli, Shangyan Zou, Rush D. Robinett Iii, David G. Wilson, Ryan G. Coe
Michigan Tech Patents
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 …
Generating Electrospray From A Ferrofluid, Lyon Bradley King
Generating Electrospray From A Ferrofluid, Lyon Bradley King
Michigan Tech Patents
An electrospray device for generating electrospray from a ferrofluid. The electrospray device includes an emitter, an extraction electrode, and a magnet. The emitter is configured to receive a ferrofluidic liquid. The extraction electrode includes an aperture and is positioned a first distance from the emitter. The magnet generates a magnetic field in a first direction toward the emitter. The magnetic field causes Rosensweig instability in the ferrofluidic liquid, and generates a ferrofluidic peak in the ferrofluidic liquid. The magnet is positioned a second distance from the emitter, and the emitter is positioned between the extraction electrode and the magnet. The …
Agent-Based Microgrid Architecture For Generation Following Protocols, Steven Goldsmith
Agent-Based Microgrid Architecture For Generation Following Protocols, Steven Goldsmith
Michigan Tech Patents
A system for predicting power and loads over a single, relatively short time horizon. More specifically, a system comprising a Storage Agent (S-agent) Cohort within a grid control society, wherein the system expands G and L intra-cohort protocols to allow the S-cohort to participate in power management of the grid by scheduling storage components in source or load roles as determined by the time-varying state of the power imbalance and by the risk-adjusting capacity margin relationship between the G and L cohorts.
Optimal Control Of Wave Energy Converters, Ossama Abdelkhalik, Rush D. Robinett Iii, Shangyan Zou, Giorgio Bacelli, David G. Wilson, Umesh Korde
Optimal Control Of Wave Energy Converters, Ossama Abdelkhalik, Rush D. Robinett Iii, Shangyan Zou, Giorgio Bacelli, David G. Wilson, Umesh Korde
Michigan Tech Patents
A wave energy converter and method for extracting energy from water waves maximizes the energy extraction per cycle by estimating an excitation force of heave wave motion on the buoy, computing a control force from the estimated excitation force using a dynamic model, and applying the computed control force to the buoy to extract energy from the heave wave motion. Analysis and numerical simulations demonstrate that the optimal control of a heave wave energy converter is, in general, in the form of a bang-singular-bang control; in which the optimal control at a given time can be either in the singular …