Patents by Inventor Rush D. Robinett, III

Rush D. Robinett, III has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10666054
    Abstract: A method for designing feedforward and feedback controllers for integration of stochastic sources and loads into a nonlinear networked AC/DC microgrid system is provided. A reduced order model for general networked AC/DC microgrid systems is suitable for HSSPFC control design. A simple feedforward steady state solution is utilized for the feedforward controls block. Feedback control laws are provided for the energy storage systems. A HSSPFC controller design is implemented that incorporates energy storage systems that provides static and dynamic stability conditions for both the DC random stochastic input side and the AC random stochastic load side. Transient performance was investigated for the feedforward/feedback control case. Numerical simulations were performed and provided power and energy storage profile requirements for the networked AC/DC microgrid system overall performance.
    Type: Grant
    Filed: May 17, 2018
    Date of Patent: May 26, 2020
    Assignees: National Technology & Engineering Solutions of Sandia, LLC, Michigan Technological University
    Inventors: David G. Wilson, Rush D. Robinett, III, Wayne W. Weaver, Steven F. Glover
  • Publication number: 20200088154
    Abstract: The present invention is directed to a nonlinear controller for nonlinear wave energy converters (WECs). As an example of the invention, a nonlinear dynamic model is developed for a geometrically right-circular cylinder WEC design for the heave-only motion, or a single degree-of-freedom (DOF). The linear stiffness term is replaced by a nonlinear cubic hardening spring term to demonstrate the performance of a nonlinear WEC as compared to an optimized linear WEC. By exploiting the nonlinear physics in the nonlinear controller, equivalent power and energy capture, as well as simplified operational performance is observed for the nonlinear cubic hardening spring controller when compared to an optimized linear controller.
    Type: Application
    Filed: August 7, 2019
    Publication date: March 19, 2020
    Inventors: David G. Wilson, Giorgio Bacelli, Rush D. Robinett, III, Ossama Abdelkhalik
  • Patent number: 10488828
    Abstract: 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 the measurement of the buoy position and velocity.
    Type: Grant
    Filed: December 4, 2017
    Date of Patent: November 26, 2019
    Assignees: National Technology & Engineering Solutions of Sandia, LLC, Michigan Technological University, South Dakota Board of Regents
    Inventors: Ossama Abdelkhalik, Shangyan Zou, Rush D. Robinett, III, David G. Wilson, Giorgio Bacelli, Ryan Geoffrey Coe, Umesh Korde
  • Patent number: 10423126
    Abstract: 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 frequencies, the implementation of the control is very simple, yet generates energy similar to the complex conjugate control.
    Type: Grant
    Filed: December 4, 2017
    Date of Patent: September 24, 2019
    Assignees: National Technology & Engineering Solutions of Sandia, LLC, Michigan Technological University
    Inventors: David G. Wilson, Rush D. Robinett, III, Ossama Abdelkhalik, Jiajun Song, Giorgio Bacelli
  • Patent number: 10415537
    Abstract: 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.
    Type: Grant
    Filed: December 11, 2017
    Date of Patent: September 17, 2019
    Assignees: National Technology & Engineering Solutions of Sandia, LLC, Michigan Technological University, South Dakota Board of Regents
    Inventors: Ossama Abdelkhalik, Rush D. Robinett, III, Shangyan Zou, David G. Wilson, Giorgio Bacelli, Umesh Korde, Ryan G. Coe
  • Patent number: 10374430
    Abstract: A controller for an electric power storage device is described herein, wherein the electric power storage device is included in a microgrid. The electric power storage device has at least one of a charge rate, a discharge rate, or a power retention capacity that has been customized for a collective microgrid. The at least one of the charge rate, the discharge rate, or the power retention capacity of the electric power storage device is computed based at least in part upon specified power source parameters in the at least two connected microgrids and specified load parameters in the at least two connected microgrids.
    Type: Grant
    Filed: January 8, 2016
    Date of Patent: August 6, 2019
    Assignee: National Technology & Engineering Solutions of Sandia, LLC
    Inventors: David G. Wilson, Rush D. Robinett, III, Steven Y. Goldsmith
  • Patent number: 10344736
    Abstract: 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.
    Type: Grant
    Filed: December 11, 2017
    Date of Patent: July 9, 2019
    Assignees: National Technology & Engineering Solution of Sandia, LLC, Michigan Technological University
    Inventors: Ossama Abdelkhalik, Giorgio Bacelli, Shangyan Zou, Rush D. Robinett, III, David G. Wilson, Ryan G. Coe
  • Patent number: 10197040
    Abstract: 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 arc mode or in the bang-bang mode. The excitation force and its derivatives at the current time can be obtained through an estimator, for example, using measurements of pressures on the surface of the buoy in addition to measurements of the buoy position.
    Type: Grant
    Filed: March 22, 2017
    Date of Patent: February 5, 2019
    Assignees: National Technology & Engineering Solutions of Sandia, LLC, Michigan Technological University, South Dakota Board of Regents
    Inventors: Ossama Abdelkhalik, Rush D. Robinett, III, Shangyan Zou, Giorgio Bacelli, David G. Wilson, Umesh Korde
  • Publication number: 20180366952
    Abstract: A method for designing feedforward and feedback controllers for integration of stochastic sources and loads into a nonlinear networked AC/DC microgrid system is provided. A reduced order model for general networked AC/DC microgrid systems is suitable for HSSPFC control design. A simple feedforward steady state solution is utilized for the feedforward controls block. Feedback control laws are provided for the energy storage systems. A HSSPFC controller design is implemented that incorporates energy storage systems that provides static and dynamic stability conditions for both the DC random stochastic input side and the AC random stochastic load side. Transient performance was investigated for the feedforward/feedback control case. Numerical simulations were performed and provided power and energy storage profile requirements for the networked AC/DC microgrid system overall performance.
    Type: Application
    Filed: May 17, 2018
    Publication date: December 20, 2018
    Inventors: David G. Wilson, Rush D. Robinett, III, Wayne W. Weaver, Steven F. Glover
  • Patent number: 10090764
    Abstract: A Hamiltonian surface shaping power flow control (HSSPFC) method is used to analyze the meta-stability and adjust pulsed power loads on a DC electric power distribution network. Pulsed power loads are nonlinear, time-variant systems that cause nonlinear limit-cycles. During the on periods of a pulsed load, the system can be in an unstable state and is damped back to stability during the off state of the load. Therefore, over the entire period of the pulse the system may only be assessed as meta-stable. As shown through simulation, HIL and hardware results, the HSSPFC method is more accurate than the other small-signal approaches, such as Eigenvalues, Nyquist, and Floquet theory, and can reveal important details about the transient responses and performance.
    Type: Grant
    Filed: January 10, 2018
    Date of Patent: October 2, 2018
    Assignees: National Technology & Engineering Solutions of Sandia, LLC, Michigan Technological University
    Inventors: David G. Wilson, Wayne W. Weaver, Rush D. Robinett, III, Ronald Matthews, Steven F. Glover
  • Publication number: 20180163690
    Abstract: 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.
    Type: Application
    Filed: December 11, 2017
    Publication date: June 14, 2018
    Inventors: Ossama Abdelkhalik, Giorgio Bacelli, Shangyan Zou, Rush D. Robinett, III, David G. Wilson, Ryan G. Coe
  • Publication number: 20180163691
    Abstract: 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.
    Type: Application
    Filed: December 11, 2017
    Publication date: June 14, 2018
    Inventors: Ossama Abdelkhalik, Rush D. Robinett, III, Shangyan Zou, David G. Wilson, Giorgio Bacelli, Umesh Korde, Ryan G. Coe
  • Publication number: 20180164755
    Abstract: 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 the measurement of the buoy position and velocity.
    Type: Application
    Filed: December 4, 2017
    Publication date: June 14, 2018
    Inventors: Ossama Abdelkhalik, Shangyan Zou, Rush D. Robinett, III, David G. Wilson, Giorgio Bacelli, Ryan Geoffrey Coe, Umesh Korde
  • Publication number: 20180164754
    Abstract: 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 frequencies, the implementation of the control is very simple, yet generates energy similar to the complex conjugate control.
    Type: Application
    Filed: December 4, 2017
    Publication date: June 14, 2018
    Inventors: David G. Wilson, Rush D. Robinett, III, Ossama Abdelkhalik, Jiajun Song, Giorgio Bacelli
  • Patent number: 9851737
    Abstract: A Unified Power Flow Controller described herein comprises a sensor that outputs at least one sensed condition, a processor that receives the at least one sensed condition, a memory that comprises control logic that is executable by the processor; and power electronics that comprise power storage, wherein the processor causes the power electronics to selectively cause the power storage to act as one of a power generator or a load based at least in part upon the at least one sensed condition output by the sensor and the control logic, and wherein at least one operating parameter of the power electronics is designed to facilitate maximal transmittal of electrical power generated at a variable power generation system to a grid system while meeting power constraints set forth by the electrical power grid.
    Type: Grant
    Filed: December 1, 2014
    Date of Patent: December 26, 2017
    Assignee: National Technology & Engineering Solutions of Sandia, LLC
    Inventors: David G. Wilson, Rush D. Robinett, III
  • Publication number: 20170298899
    Abstract: 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 arc mode or in the bang-bang mode. The excitation force and its derivatives at the current time can be obtained through an estimator, for example, using measurements of pressures on the surface of the buoy in addition to measurements of the buoy position.
    Type: Application
    Filed: March 22, 2017
    Publication date: October 19, 2017
    Inventors: Ossama Abdelkhalik, Rush D. Robinett, III, Shangyan Zou, Giorgio Bacelli, David G. Wilson, Umesh Korde
  • Patent number: 9721312
    Abstract: An electric power storage device included in a microgrid is described herein. The electric power storage device has at least one of a charge rate, a discharge rate, or a power retention capacity that has been customized for the microgrid. The at least one of the charge rate, the discharge rate, or the power retention capacity of the electric power storage device is computed based at least in part upon specified power source parameters in the microgrid and specified load parameters in the microgrid.
    Type: Grant
    Filed: July 11, 2012
    Date of Patent: August 1, 2017
    Inventors: Steven Y. Goldsmith, David G. Wilson, Rush D. Robinett, III
  • Patent number: 9263894
    Abstract: An electric power storage device is described herein, wherein the electric power storage device is included in a microgrid. The electric power storage device has at least one of a charge rate, a discharge rate, or a power retention capacity that has been customized for a collective microgrid. The collective microgrid includes at least two connected microgrids. The at least one of the charge rate, the discharge rate, or the power retention capacity of the electric power storage device is computed based at least in part upon specified power source parameters in the at least two connected microgrids and specified load parameters in the at least two connected microgrids.
    Type: Grant
    Filed: May 25, 2012
    Date of Patent: February 16, 2016
    Assignee: Sandia Corporation
    Inventors: Rush D. Robinett, III, David G. Wilson, Steven Y. Goldsmith
  • Patent number: 9140231
    Abstract: A wave energy converter (WEC) is described, the WEC including a power take off (PTO) that converts relative motion of bodies of the WEC into electrical energy. A controller controls operation of the PTO, causing the PTO to act as a motor to widen a wave frequency spectrum that is usable to generate electrical energy.
    Type: Grant
    Filed: October 7, 2013
    Date of Patent: September 22, 2015
    Assignee: Sandia Corporation
    Inventors: David G. Wilson, Diana L. Bull, Rush D. Robinett, III
  • Patent number: 8930034
    Abstract: A Unified Power Flow Controller described herein comprises a sensor that outputs at least one sensed condition, a processor that receives the at least one sensed condition, a memory that comprises control logic that is executable by the processor; and power electronics that comprise power storage, wherein the processor causes the power electronics to selectively cause the power storage to act as one of a power generator or a load based at least in part upon the at least one sensed condition output by the sensor and the control logic, and wherein at least one operating parameter of the power electronics is designed to facilitate maximal transmittal of electrical power generated at a variable power generation system to a grid system while meeting power constraints set forth by the electrical power grid.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: January 6, 2015
    Assignee: Sandia Corporation
    Inventors: David G. Wilson, Rush D. Robinett, III