Abstract: A spring suspension system includes a top spring assembly connected to a top end of a stator and a top end of a cable and a bottom spring assembly connected to a bottom end of the stator and a bottom end of the cable. The top spring assembly includes a central spring connected to the top end of the cable at a bottom end of the central spring and a set of symmetrically arranged springs, each connected to the top end of the stator and to a top end of the central spring, configured to accommodate torsional and rotational components of an input force.

Abstract: The present invention relates to a method for charging a DC link of a power converter included in a wind turbine generator, the wind turbine generator comprising a generator side converter connected to an electrical generator and a grid side converter connectable, or connected, to an electrical grid through a grid circuit breaker, and a converter controller arranged to control at least the DC link, the DC link having a DC voltage level, the wind turbine generator comprising a wind turbine rotor arranged to rotate the electrical generator, wherein the method comprises rotating the wind turbine rotor whereby the electrical generator generates electrical power, rectifying the electrical power through at least one diode of the generator side converter in order to pre-charge the DC link to a DC voltage level, closing the grid circuit breaker when the DC voltage level is greater than a threshold level.

Abstract: Methods and systems described herein relate to power generation control for an aerial vehicle of an air wind turbine (AWT). More specifically, the methods described herein relate to balancing power generation or preventing a component of the aerial vehicle from overheating using rotor speed control. An example method may include operating an aerial vehicle in a crosswind-flight mode to generate power. The aerial vehicle may include a rotor configured to help generate the power. While the aerial vehicle is in the crosswind-flight mode the method may include comparing a power output level of the aerial vehicle to a power threshold and, based on the comparison, adjusting operation of the rotor in a manner that generates an optimal amount of power or minimizes overheating of the aerial vehicle.

Abstract: An apparatus for facilitating use of instruments in hazardous environments includes a fluid line and a fluid-driven generator. The fluid line includes: an inlet to receive a flow of fluid from a fluid source; a first outlet to convey a first portion of the fluid flow to an instrument as a purge gas; and a second outlet to convey a second portion of the fluid flow. The fluid-driven generator is coupled to the second outlet of the fluid line, and converts fluid-stored energy in the second portion of the fluid flow to electrical energy deliverable to the instrument as the second portion of the fluid flow is received from the second outlet.

Abstract: Methods and systems described herein relate to power generation control for an aerial vehicle of an air wind turbine (AWT). More specifically, the methods described herein relate to balancing power generation or preventing a component of the aerial vehicle from overheating using rotor speed control. An example method may include operating an aerial vehicle in a crosswind-flight mode to generate power. The aerial vehicle may include a rotor configured to help generate the power. While the aerial vehicle is in the crosswind-flight mode the method may include comparing a power output level of the aerial vehicle to a power threshold and, based on the comparison, adjusting operation of the rotor in a manner that generates an optimal amount of power or minimizes overheating of the aerial vehicle.

Abstract: A tunable generator has a surface structure for contacting an exterior fluid flow relative to a base structure. The contacting surface structure also has an electrogenerative portion positioned relative to the contacting structure and the base structure. The electrogenerative portion is preferably a piezoelectric or electromagnetic structure, although other types of structures are known within the art. The contacting surface is mechanically coupled to portions of the base structure through one or more elastic elements. The various portions of the base structure can be positioned relative to other base structure portions to alter the elasticity of the system or the tensioning of the elastic elements. The field of flow exerts forces upon the contacting structure which causes movement in the contacting surface structure relative to the base structure through the electrogenerative portion.

Abstract: A wind turbine includes a grid side converter coupled to a grid via a power line. The method includes determining a first active power reference and a first reactive power reference indicating a requested amount of active power and reactive power, respectively, depending on at least a wind turbine operation strategy; determining a positive and negative sequence components of a grid voltage; determining indications of an actual amount of active power and reactive power to be supplied by the grid side converter to the grid, respectively; generating a parameters defining a proportion of positive sequence current component and negative sequence current component to be injected by the grid side converter in order to supply active power and reactive power; and supplying, with the grid side converter, active and reactive power to the power line based on the current reference.

Abstract: An alternator has a field coil that produces a magnetic field which induces electricity in a coil arrangement. A field coil excitation system includes a generator with an output coil assembly for producing alternating electricity. A rectifier converts the alternating electricity into voltage and direct current at two nodes. A capacitor, between the nodes, has capacitance that forms a resonant circuit with inductance of the output coil assembly. Due to that resonant circuit, the voltage and direct current oscillate in a predefined phase relationship. A switch and the field coil are connected in series between the nodes. A controller renders the switch conductive for a time period specified by a received control signal. The switch is rendered non-conductive at the first occurrence of a minimum current level after the time period ends. The predefined phase relationship enables the minimum current level to be detected by sensing the voltage.

Abstract: A co-generation apparatus for the generation of electricity from an external source of forced air is described in which the co-generation apparatus comprises a turbine, a generator, a co-generation control unit, and an adjustable standoff. The turbine is connected to the generator for the production of electricity. The generator interface electrically connects the generator to an electrical system. The co-generation control unit is connected to the turbine and generator interface. The forced air drives the turbine. The turbine can be positioned in a turbine housing that receives the forced air. An adjustable standoff is connected to the turbine. The standoff adjusts the position of the turbine relative to the forced air.

Abstract: The invention relates to a variable rotor speed wind turbine transmitting AC electric power to a utility grid. The wind turbine includes at least one AC generator and at least two power electronic converter units. Further, it includes means for transforming at least one nominal output value of the generator to at least one different nominal input value of the at least two power electronic converter units. The invention also relates to a wind park and a method of transmitting AC electric power to a utility grid from a variable rotor speed wind turbine as well as a method of servicing or inspecting a variable rotor speed wind turbine.

Abstract: A hydraulic damper (100) comprises a cylinder (10) with a bottom wall (11), a head wall (12) and side walls (13) that define a damping chamber (15) containing a damping fluid (17); in the damping chamber (15) a piston (20) slides with a first face (20a) and a second face (20b) opposite to each other. In particular, the piston (20) defines a first chamber (21) and a second chamber (22) separate from each other and is integral to a shaft (25) with an external connection end (36). The piston (20) is suitable for carrying out a forward stroke (A), between a first dead point (BDP), towards a second dead point (TDP) and a back stroke (B) between the second dead point (TDP) and the first dead point (BDP).

Abstract: An energy regeneration device of a suspension system for a vehicle, includes a suspension link that connects a wheel carrier to a vehicle body, a bush unit that is disposed between a vehicle body connection portion of the suspension link and the vehicle body and outputs hinge motion of the suspension link through an output gear, a one-way power transmission mechanism that is connected with the output gear of the bush unit, receives the hinge motion transmitted from the output gear through an input gear, and outputs only one-way rotational power, and a generator that is disposed at a side of the vehicle body and generates electricity while being rotated by the transmitted one-way rotational power.

Abstract: A liquid damper in a wind turbine is provided. A damper system of a direct driven wind turbine is disclosed, whereby the wind turbine comprises a nacelle, a rotor hub and an electric generator. The electric generator comprises a rotor and a non-rotating part. The rotor hub is connected to the rotor of the electric generator. The non-rotating part of the generator is connected to the nacelle. The wind turbine comprises a damper system to at least partially eliminate an unwanted movement of the wind turbine resulting from wind loads, whereby the damper system comprises a liquid damper. The damper system is arranged at a non-rotating part of the electric generator.

Abstract: A device for conversion of energy of a wave of water comprises a front (11) and a back (12) opposite the front (11), a top (13) and a bottom (14) opposite the top (13), an inlet chamber (15) which has a partition (16), an inlet valve (17) at the front (11) between the top (13) and the partition (16) and an inlet chamber vent (18), wherein the inlet valve (17) allows flow of water in one direction into the inlet chamber (15). An outlet chamber (19) has an outlet valve (20) between the partition (16) and the bottom (14), and an outlet chamber vent (21) positioned between the partition (16) and the top (13), adapted to maintain atmosperic pressure of air in the outlet chamber (19), wherein the outlet valve (20) allows flow of water in one direction out of the outlet chamber (19).

Abstract: Methods of controlling a variable speed wind turbine generator connected to a power grid. The method may include measuring the frequency, f, of the power grid, controlling the speed of the generator for optimizing the power delivered to the power grid, and setting limits for the generator speed. The setting of the limits for the generator speed is performed in dependency of the measured frequency of the power grid. This provides a dynamical set of limits providing improved possibilities of optimizing the power production.

Abstract: In a rotary electric machine, an on-timing setter sets on-timings of each of a high-side switching element and a low-side switching element for each of at least two three-phase stator windings. An off-timing setter sets off-timings of each of the high-side switching element and the low-side switching element. An off-timing fault determiner determines a fault of an off-timing of a target switching element as one of the high-side switching element and the low-side switching element set by the off-timing setter when a time interval from the off-timing of the target switching element set by the off-timing setter to time when a phase voltage corresponding to the target switching element reaches a threshold after the off-timing thereof is shorter than a preset value.

Abstract: An electrical generator includes a stator having fractional-slot concentrated windings and a rotor having field windings. A drive is provided having a circuit to control current flow to the field windings and a controller to input an initial DC field current demand to the circuit to cause the circuit to output an initial DC field current representative of a DC field current demand that would cause an electrical generator having sinusoidal stator windings to output a desired AC power. The controller receives feedback on the magnetic field generated by the initial DC field current, isolates an ideal fundamental component of the magnetic field based on the feedback and to generate a modified DC field current demand, and inputs the modified DC field current demand to the circuit, thereby causing the circuit to output an instantaneous non-sinusoidal current to the field windings to generate a sinusoidal rotating air gap magnetic field.

Abstract: An underwater apparatus for generating electric power from ocean currents and deep water tides. A submersible platform including two or more power pods, each having a rotor with fixed-pitch blades, with drivetrains housed in pressure vessels that are connected by a transverse structure providing buoyancy, which can be a wing depressor, hydrofoil, truss, or faired tube. The platform is connected to anchors on the seafloor by forward mooring lines and a vertical mooring line that restricts the depth of the device in the water column. The platform operates using passive, rather than active, depth control. The wing depressor, along with rotor drag loads, ensures the platform seeks the desired operational current velocity. The rotors are directly coupled to a hydraulic pump that drives at least one constant-speed hydraulic-motor generator set and enables hydraulic braking. A fluidic bearing decouples non-torque rotor loads to the main shaft driving the hydraulic pumps.

Abstract: A control system to improve the production of a variable speed wind turbine comprising control devices for a standard regulation tracking a power vs. generator speed curve that also uses an alternative regulation for optimizing the energy production along determinate time periods Tb for compensating previous energy losses at a higher power Pb than the power determined by the standard regulation, the alternative regulation being based on a continuous calculation of the accumulated lost energy ALE as the energy lost with respect to the maximum allowed energy production according to the standard regulation and the fixation of the higher power Pb and a setting of the duration of the time periods Tb being compatible with wind turbine electrical or mechanical limitations. A wind turbine controlled by the method.

Abstract: The invention relates to a device for harnessing energy from a body of water, which device comprises a Darrieus rotor having at least two Darrieus rotor blades, and comprises at least two connecting arms which connect the Darrieus rotor blades with a central axis, wherein per Darrieus rotor blade a first, proximal section of a connecting arm is connected to the central axis and a point of the connecting arm situated at a distance of the proximal section is connected to a first point on the Darrieus rotor blade, wherein at least the connection between the point of a connecting arm situated at a distance of the first proximal section and the first point on a Darrieus blade is a hingable connection, for every Darrieus rotor blade, of at least one connecting arm the connection between the proximal section of the connecting arm and the central axis is a rigid connection.