Abstract: In an example embodiment, a system includes a plurality of drive units coupled to a plurality of propellers. Each drive unit includes a single motor/generator and a single motor controller, and the plurality of drive units includes a first drive-unit pair and a second drive-unit pair. The system also includes a high-voltage bus connecting the motor controllers in the first drive-unit pair to a tether, a low-voltage bus connecting the motor controllers in the second drive-unit pair to the tether, and an intermediate-voltage bus connecting the motor controllers of the first drive-unit pair in series with the motor controllers of the second drive-unit pair. The motor controllers in the first drive-unit pair are connected in parallel via the high-voltage bus and the intermediate-voltage bus, and the motor controllers in the second drive-unit pair are connected in parallel via the intermediate-voltage bus and the low-voltage bus.

Abstract: A motor control topology relevant to airborne wind turbines and a control process for such a motor control topology is disclosed herein.

Abstract: A motor control topology relevant to airborne wind turbines and a control process for such a motor control topology is disclosed herein. A system may include an aerial vehicle that may include a plurality of propellers, a plurality of drive units coupled to the plurality of propellers, and a tether. Each drive unit may include a motor/generator and a motor controller. The plurality of drive units may include at least two pairs of drive units that include a first drive-unit pair and a second drive-unit pair. The drive units in each drive pair may be connected in parallel, and the at least two pairs of drive units may be connected in series. The drive units may be configured to operate in a first mode and operate in a second mode.

Abstract: Wind energy systems, such as an Airborne Wind Turbine (“AWT”), may be used to facilitate conversion of kinetic energy to electrical energy. An AWT may include an aerial vehicle that flies in a path to convert kinetic wind energy to electrical energy. The aerial vehicle may be tethered to a ground station with a tether that terminates at a tether termination mount system. In one aspect, the tether termination mount system may include a tether termination unit configured in one or more gimbals that allow for the tether termination unit to rotate about one or more axes while tracking the aerial vehicle in flight. In a further aspect, the tether termination mount system may include an imaging device configured for imaging the aerial vehicle during flight in order to enhance tracking accuracy over that which is performed by angular motion of the tether termination unit.

Abstract: Wind energy systems, such as an Airborne Wind Turbine (“AWT”), may be used to facilitate conversion of kinetic energy to electrical energy. An AWT may include an aerial vehicle that flies in a path to convert kinetic wind energy to electrical energy. The aerial vehicle may be tethered to a ground station with a tether that terminates at a tether termination mount. In one aspect, the tether may be a conductive tether that can transmit electricity and/or electrical signals back and forth between the aerial vehicle and the ground station. The tether termination mount may include one or more gimbals that allow for the tether termination mount to rotate about one or more axis. In a further aspect, the tether termination mount may include a slip ring that allows for rotation of the tether without twisting the tether.

Abstract: Wind energy systems, such as an Airborne Wind Turbine (“AWT”), may be used to facilitate conversion of kinetic energy to electrical energy. An AWT may include an aerial vehicle that flies in a path to convert kinetic wind energy to electrical energy. The aerial vehicle may be tethered to a ground station with a tether that terminates at a tether termination mount. In one aspect, the tether may be a conductive tether that can transmit electricity and/or electrical signals back and forth between the aerial vehicle and the ground station. The tether termination mount may include one or more gimbals that allow for the tether termination mount to rotate about one or more axis. In a further aspect, the tether termination mount may include a slip ring that allows for rotation of the tether without twisting the tether.

Abstract: Wind energy systems, such as an Airborne Wind Turbine (“AWT”), may be used to facilitate conversion of kinetic energy to electrical energy. An AWT may include an aerial vehicle that flies in a path to convert kinetic wind energy to electrical energy. The aerial vehicle may be tethered to a ground station with a tether that terminates at a tether termination mount system. In one aspect, the tether termination mount system may include a tether termination unit configured in one or more gimbals that allow for the tether termination unit to rotate about one or more axes while tracking the aerial vehicle in flight. In a further aspect, the tether termination mount system may include an imaging device configured for imaging the aerial vehicle during flight in order to enhance tracking accuracy over that which is performed by angular motion of the tether termination unit.

Abstract: Wind energy systems, such as an Airborne Wind Turbine (“AWT”), may be used to facilitate conversion of kinetic energy to electrical energy. An AWT may include an aerial vehicle that flies in a path to convert kinetic wind energy to electrical energy. The aerial vehicle may be tethered to a ground station with a tether that terminates at a tether termination mount. In one aspect, the tether may be a conductive tether that can transmit electricity and/or electrical signals back and forth between the aerial vehicle and the ground station. The tether termination mount may include one or more gimbals that allow for the tether termination mount to rotate about one or more axis. In a further aspect, the tether termination mount may include a slip ring that allows for rotation of the tether without twisting the tether.

Abstract: Wind energy systems, such as an Airborne Wind Turbine (“AWT”), may be used to facilitate conversion of kinetic energy to electrical energy. An AWT may include an aerial vehicle that flies in a path to convert kinetic wind energy to electrical energy. The aerial vehicle may be tethered to a ground station with a tether that terminates at a tether termination mount. In one aspect, the tether may be a conductive tether that can transmit electricity and/or electrical signals back and forth between the aerial vehicle and the ground station. The tether termination mount may include one or more gimbals that allow for the tether termination mount to rotate about one or more axis. In a further aspect, the tether termination mount may include a slip ring that allows for rotation of the tether without twisting the tether.

Abstract: An electric power generation system is disclosed. The electric power generation system comprises a string configured to be pulled. The electric power generation system further comprises a bobbin configured to rotate when the string is unwound from the bobbin. The electric power generation system further comprises an electric power generator having a rotor. The rotor is configured to rotate such that the ratio of number of rotations of the rotor and the bobbin is 1:1 when the string is being pulled.

Abstract: An electric power generation system is disclosed. The electric power generation system includes: a first string and a second string configured to be pulled; a first portion of a bobbin configured to rotate in a direction when the first string is unwound from the bobbin as the first string is pulled; a second portion of a bobbin configured to rotate in the direction when the second string is unwound from the bobbin as the second string is pulled; and an electric power generator having a rotor wherein the rotor is mechanically coupled to the bobbin. The pulling of the second string causes the first string to retract and the pulling of the first string causes the second string to retract.

Abstract: A wind power generating system is disclosed. The wind power generating system comprises a plurality of blades to capture wind energy; a shaft coupled to the plurality of blades, and a power extractor for extracting power from the rotation of the plurality of blades. A rotation of the plurality of blades occurs in response to the captured wind energy, and a lift force is generated from the captured wind energy by the plurality of blades that is substantially along the shaft.

Abstract: A system for power generation comprises a wing, a turbine, a tether, and a tether tension sensor. The wing is for generating lift. The turbine is coupled to the wing and is used for generating power from rotation of a propeller or for generating thrust using the propeller. One end of the tether is coupled to the wing. The tether tension sensor is for determining a tension of the tether.

Abstract: A method of coupling a mechanical power source through an electrical power generator to an electrical load is disclosed. A characteristic of an electrical output is measured from the electrical power generator produced during a power generation cycle during which there is a coupling of the mechanical power source through the electrical power generator to the electrical load. The coupling of the mechanical power source is adjusted through the electrical power generator to the electrical load during a subsequent power generation cycle based at least in part on the measured characteristic of the electrical output.

Abstract: A power generation system is disclosed. The power generation system comprises a kite connected to a line. The line is alternatively let out during a traction phase and recovered during a recovery phase. A power extractor connected to the line to extract power during the traction phase. And, a power extraction controller configured to target a preferred traction phase line velocity and a preferred recovery phase line velocity.

Abstract: Release systems for tensioned lines, which release under a predetermined change in tension; particularly systems for use in towing airfoils for sports and recreational activities coupling the airfoil to a rider.

Abstract: A towable lift system and components and accessories therefore, particularly for use in sports and recreational activities coupling the airfoil to a rider.

Abstract: A tether for a kite wind power system is disclosed. The tether has a cross-section that is designed to have less aerodynamic drag than a tether with a circular-shaped cross-section.

Abstract: For use with towable airfoils used to supply lift to a towed rider to assist with jumping in sports and recreation, a handle system having one or more control lines for coupling to the airfoil, and a line for coupling the handle to a tow vehicle, the one or more control lines and line for coupling to the tow vehicle being coupled together by a tension translation mechanism that divides the tension from the line for the tow vehicle to the one or more control lines by a predetermined factor, which typically would be other than 1:1. The handle system may further include an engagement mechanism for engaging the one or more control lines to lock or brake a line.

Abstract: A kite is disclosed. The kite comprises a first control element coupled to the kite in a first tether-force configuration, wherein the first control element is used to maintain controlled flight of the kite in the first tether-force configuration during a power generating phase.