X Development LLC

Makani Technologies LLC

Google Inc.

Elias Wolfgang Patten

Damon Vander Lind

Brian Hachtmann

Bryan Christopher GilroySmith

Leo Francis Casey

Abhimanyu Belani

Joel Fraser Atwater

Charles Nordstrom

Robert J Nelson

Geoff Dolan

Fort Felker

George Homsy

Corwin Hardham

Kurt Hallamasek

Kenny Jensen

Rob Nelson

Robbie Philip Su

Kurt Hallamask

Robert S Sellers

Gabriel Murphy

An example system includes a ground station, an aerial vehicle, a tether, a probe, and a control system. The tether includes a core having a strength member as well as an electrical conductor that is wound around the core. The probe is attached to the strength member so that the probe is able to measure an electrical property of at least a portion of the strength member. The control system is configured to measure the electrical property along the strength member at a predetermined measurement rate and also determine that the electrical property is outside a predetermined range. Based on the electrical property, damage to the tether core can be assessed.

Methods, systems, and devices for tether core diagnostics and monitoring

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 has a core and at least one electrical conductor. The tether core may be terminated at a first location in a tether termination mount along an axis of the termination mount, and the at least one electrical conductor may be terminated at a second location in the tether termination mount along the same axis that the core is terminated. This termination configuration may focus tensile stress on the tether to the tether core, and minimize such stress on the at least one electrical conductor during aerial vehicle flight.

Airborne wind turbine tether termination systems

Faired tethers with internal support structures providing support to strength cores, and systems therewith, are described. The faired tethers include one or more electrical conductors and one or more rigid supports that inhibit movement of a strength core within a faired tether.

Faired tether systems with internal support structure in the faired tether

Tensile cables with transmission cables arranged in undulating paths are described. The tensile cables include deformable supports that define the undulating paths and deform in response to a tension force exerted on opposing ends of the transmission cables.

High-elongation tensile cable with undulating transmission cable

A tether guide operable through a wide range of tether/fleeting angles while causing minimal wear and having a reduced size compared to a levelwind wheel. The tether guide may include a series of rollers approximating the curved shape and radius of levelwind wheel. The tether guide may include downward facing guide wings matched to a curved roller profile, but flaring out to capture and guide tether into rollers. Sensors may be included on the tether guide to provide information about tether location, including whether the tether is engaged in the tether guide.

Sensor equipped tether guide with open tether channel

A system for carrying a tether guide, including a counter-balanced support system with two pivot points, where a first pivot allows the tether guide to travel up and down and the second pivot allows the tether guide to match the tether angle. Both pivots may be passive pivots. A shuttle that carries the tether guide may be electronically cammed to follow variable pitch helical grooves of a winch drum as the tether guide traverses across the drum length.

Floating counter-balanced levelwind carrier system

Airborne wind turbine systems with multiple aerial vehicles connected via multiple tethers to a single ground station are disclosed. A node is coupled to the tethers. The node includes a drive system. At a proximate end of the node, each of the tethers is adjacent to neighboring tethers. And at a distal end of the node, each of the tethers is separated from the neighboring tethers. The airborne wind turbine system includes a control system configured to operate the drive system to translate the node along the tethers.

Nodes for multiple aerial vehicles connected to a single ground station

A tether may include a core, a hybrid layer surrounding the core, and a jacket surrounding the hybrid layer. The hybrid layer may include a plurality of strength members, and a plurality of electrical conductor bundles. Each electrical conductor bundle of the plurality of electrical bundles may include a compliant element, a plurality of electrical conducting elements surrounding the compliant element, and an insulating layer surrounding the plurality of electrical conducting elements.

Tethers for airborne wind turbines using electrical conductor bundles

A tether may include a core, a plurality of electrical conductors wound around the core, and a jacket surrounding the plurality of electrical conductors. The plurality of electrical conductors may include at least two groups of electrical conductors. Each group of electrical conductors of the at least two groups of electrical conductors may define a respective electrical path, where the respective electrical path is different from the electrical paths defined by other groups of electrical conductors of the at least two groups of the electrical conductors. Moreover, each group of electrical conductors of the at least two groups of electrical conductors is located around a respective portion of the core, such that a cross-section of each group of electrical conductors of the at least two or more electrical conductors defines a respective arc around the respective portion of the core.

Tethers for airborne wind turbines

A system may include a tether, a slip ring, a tether gimbal assembly, a drive mechanism, a control system. The tether may include a distal tether end coupled to an aerial vehicle, a proximate tether end, and at least one insulated electrical conductor coupled to the aerial vehicle. The slip ring may include a fixed portion and a rotatable portion, where the rotatable portion is coupled to the tether. The tether gimbal assembly may be rotatable about at least one axis and is coupled to the fixed portion of the slip ring. The drive mechanism may be coupled to the slip ring and configured to rotate the rotatable portion of the slip ring. And the control system may be configured to operate the drive mechanism to control twist in the tether.

Systems and methods for controlling rotation and twist of a tether

Embodiments described herein may relate to power-line communication (PLC) systems that are suitable for high-voltage and electrically noisy applications. In one example system, PLC technology is used to carry data on at least one pair of conductors of a high-voltage (e.g., kilovolt) transmission line that is simultaneously used for power transmission. Further, in some instances, the transmission line may be part of a tether that connects an aerial vehicle to a ground station.

Low-power wide-band communication links in high-voltage transmission lines

Tether termination systems and methods

An energy kite may be coupled to a tether and ground station. The tether or other cables may need to be terminated, where one or more components of the cable need to be separated and terminated individually. In energy kite systems, it is common for the tether (or other cables) to have small mass and diameter. The termination may also include a first potted region with a softer potting material and a second potted region with a harder potting material.

Combined electrical and mechanical potted termination for a center strength member cable

A system may include a tether, a tether gimbal assembly, a drive mechanism, and a control system. The tether may include a distal end, a proximate end, and at least one conductor. The tether gimbal assembly may be connected to the tether. The drive mechanism may be coupled to the tether gimbal assembly and may include a housing, a spindle, and a motor. The housing may be fixed to the tether gimbal assembly. The spindle may be rotatably coupled to the housing, and the tether may be coupled to the spindle and rotate in conjunction with the spindle. The motor may be coupled to the spindle and configured to rotate the spindle and the tether. And the control system may be configured to operate the drive mechanism to control twist in the tether.

Drive mechanisms for use in controlling rotation and twist of a tether

A system includes: a tension member having a first end and a second end, where the first end of the tension member is connected to a first loading member and the second end of the tension member is connected to a second loading member; a first actuator configured to translate the first loading member, such that a tensile load is applied to the tension member along a first direction; a second actuator configured to translate the second loading member in two or more second directions that are substantially transverse to the first direction; and a control system that is configured to control the second actuator, such that the second loading member oscillates between the two or more second directions, where the oscillation of the second loading member causes the tension member to vibrate at a frequency.

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Seattle, WA, United States of America

Elias Wolfgang Patten