Abstract: A liquid treatment system that may be self-powered includes a filter, an ultraviolet light source and a hydro-generator. A flow of liquid may be filtered with the filter and used to rotate the hydro-generator to generate electric power. The ultraviolet light source may be energized by the electric power generated by the hydro-generator when the magnitude of electric power of the hydro-generator enters a determined range. The flow of liquid may be subject to ultraviolet energy generated by the ultraviolet light source.

Abstract: Disclosed are a compressed air energy-storing electricity generating system and an electricity generating method using the same, in which air of a high pressure is injected into a tank laid under the ground using midnight electricity and surplus produced electricity, and the air of the high pressure in the tank is uniformly discharged so as to drive a generator during a time period when the consumption of electric power is high, thus efficiently managing energy.

Abstract: Methods and apparatus are disclosed for harvesting energy from motion of one or more joints. Energy harvesters comprise: a generator for converting mechanical energy into corresponding electrical energy; one or more sensors for sensing one or more corresponding characteristics associated with motion of the one or more joints; and control circuitry connected to receive the one or more sensed characteristics and configured to assess, based at least in part on the one or more sensed characteristics, whether motion of the one or more joints is associated with mutualistic conditions or non-mutualistic conditions. If conditions are determined to be mutualistic, energy harvesting is engaged. If conditions are determined to be non-mutualistic, energy harvesting is disengaged.

Abstract: A buoyancy vehicle apparatus includes a water or liquid source, such as a water tank, and a buoyant mass in communication with an electrical generator. The buoyant mass is lifted from a lower level to a higher level to store energy. The mass is stored at the predetermined height and released to travel downward when the electricity is needed. After the mass is released and pulled down by gravity, it will drive the generator to produce electricity. The system can store this energy with no loss in power over a long period of time.

Abstract: The invention provides means of limiting maximum current conducted through windings of an electric machine having a rotor and a stator. By encouraging an appropriate leakage flux around a winding, a leak impedance can be achieved which may be used, according to the invention, to limit the maximum current in the winding as a matter of machine design.

Abstract: The present invention provides a power converter that can be used to interface a generator (4) that provides variable voltage at variable frequency to a supply network operating at nominally fixed voltage and nominally fixed frequency and including features that allow the power converter to remain connected to the supply network and retain control during supply network fault and transient conditions. The power converter includes a generator bridge (10) electrically connected to the stator of the generator (4) and a network bridge (14). A dc link (12) is connected between the generator bridge (10) and the network bridge (14). A filter (16) having network terminals is connected between the network bridge (14) and the supply network. A first controller (18) is provided for controlling the operation of the semiconductor power switching devices of the generator bridge (14).

Abstract: A brushless generator with permanent-magnet multi-pole rotor disks and coreless stator winding disks includes integral electronics to efficiently generate regulated DC current and voltage from shaft input power over a broad speed range. Its power rating is scalable, and it incurs no cogging torque, or friction from gearing. Integral power control electronics includes high-frequency pulse-width-modulated boost regulation, which provides regulated current at requisite voltage over its broad speed range. A main embodiment to produce DC power at widely variable speeds includes signal processing so output power varies according to the third power of speed. A version for use with vertical-axis wind turbines has a relatively large diameter to facilitate a large number of poles. Combined boost-regulation, zero cogging torque, and no gearing, enable a wide speed range, for better power quality and higher wind energy yields.

Abstract: A system for generating electricity from the rotational movement of wheels of a vehicle incorporates a turbine assembly, a wheel assembly, and an apparatus for storing electricity. The turbine assembly is disposed within the wheel assembly. The turbine assembly is connected to the apparatus for storing electricity thereby supplying the apparatus for storing electricity with electricity produced by the rotational movement of the wheel. The turbine assembly is comprised of a hollow rotor and a stator. The stator is disposed longitudinally within the hollow rotor.

Abstract: This disclosure relates to transient energy systems for supplying power to a load substantially instantaneously on demand. Transient energy systems may include a flywheel coupled the rotor of an induction motor generator. One embodiment of the disclosure refers to systems and methods for reducing loads on a bearing in a transient energy system. In another embodiment, the disclosure refers to an induction motor generator that is optimized for high power transient power generation, yet low power motor operation. Yet another embodiment of the disclosure refers to using a flywheel as a drag pump to cool components of a transient energy system. In yet another embodiment, a slip control scheme is discussed for regulating a DC bus. In yet a further embodiment of the disclosure a method is provided for reducing unnecessary turbine starts by making turbine start a function of the rotational velocity of a flywheel.

Abstract: Wind power installations were initially always erected in the form of individual units and it is only in recent years that, caused also by administrative and building regulations, wind power installations are frequently installed in wind parks. In that respect a wind park in its smallest unit is an arrangement of at least two wind power installations, but frequently markedly more. By way of example mention may be made of the wind park at Holtriem (East Frisia) where more than 50 wind power installations are set up in an array. It is to be expected that the number of units and also the installed power of the wind power installations will also increase greatly in the forthcoming years. In most cases the wind potential is at its greatest in regions of the power supply networks with a low level of short-circuit power and low population density.

Abstract: A method for the operation of a wind energy plant, with control of a reactive electric variable which is to be provided, wherein a desired value for the reactive electric variable is determined as follows: a first upper and/or a first lower limit value of the grid voltage is defined for the grid voltage, when the real value of the grid voltage exceeds the first upper limit value and/or the real value of the grid voltage falls below the first lower limit value, the desired value of the reactive electric variable is increased or diminished such that the deviation of the real value of the grid voltage from its desired value is counter-acted, wherein the desired value of the reactive electric variable is continuously increased or diminished further over the time, as long as the real value of the grid voltage exceeds the first upper limit value or falls below the first lower limit value.

Abstract: A feedback control method and circuit for inclusion in a control system of an electrical power generating source that comprises a free piston Stirling engine driving a linear alternator. An instantaneous value of a variable, Vinternal, is continuously derived from other sensed and computed parameters and used in a negative feedback control loop of the control system to control engine piston stroke in order to maintain the power produced by the engine equal to the power transferred from the engine to the alternator. Vinternal is the sum of the voltage induced on the alternator winding and the voltage across the equivalent circuit lumped resistance of the alternator winding. A switching mode rectifier connects the alternator winding to an energy storage capacitor or battery. A negative feedback, alternator current control loop has an output connected to the pulse width modulator of the switching mode rectifier and has a feedback circuit comprising a current sensor for sensing instantaneous alternator current.

Abstract: A floating wind turbine system with a tower structure that includes at least one stability arm extending therefrom and that is anchored to the sea floor with a rotatable position retention device that facilitates deep water installations. Variable buoyancy for the wind turbine system is provided by buoyancy chambers that are integral to the tower itself as well as the stability arm. Pumps are included for adjusting the buoyancy as an aid in system transport, installation, repair and removal. The wind turbine rotor is located downwind of the tower structure to allow the wind turbine to follow the wind direction without an active yaw drive system. The support tower and stability arm structure is designed to balance tension in the tether with buoyancy, gravity and wind forces in such a way that the top of the support tower leans downwind, providing a large clearance between the support tower and the rotor blade tips.

Abstract: A method and apparatus of assembling a rotary machine includes providing at least one component. The component is at least one of a rotating member and a stationary member. The method and apparatus also includes coupling the component to a monocoque nacelle structure. The monocoque nacelle structure includes an outer shell that extends over at least a portion of the component.

Abstract: The method for operating a frequency converter (26) of a generator (14) in particular of a wind energy turbine (10), in the event of a substantial grid voltage drop, wherein the frequency converter (26) comprises a generator-side power converter (32), to be connected to the generator (14), a grid-side power converter (28) to be connected to the voltage grid (18), and a DC link circuit (30) for connecting the generator-side power converter (32) to the grid-side power converter (28), comprises the step of generating the amount of reactive current to be supplied to the grid (18) by controlling the frequency converter (26).

Abstract: A device for providing a regulated, limited generator excitation current to a generator to acquire a regulated output voltage of the generator, the device including a combiner for weighted combining a first system deviation on the basis of a setpoint voltage and of the regulated output voltage, and a second system deviation on the basis of a predefined current value and of the regulated generator excitation current so as to acquire a combination signal based on the combination of the first system deviation and the second system deviation, a provider for providing a actuating variable on the basis of the combination signal and a regulation specification, and a provider for providing the regulated, limited generator excitation current to the generator on the basis of the actuating variable, so that the regulated output voltage may be provided by the generator.

Abstract: A method of driving a linear motor having a multi-phase coil as a stator or a movable element includes the steps of positioning the stator at a position where a driving electric power becomes largest, and driving the movable element relative to the stator.

Abstract: An energy conversion system includes a first mechanical system for converting reciprocating motion to rotary motion, a second system formed of belts and pulleys connected to said first system and driven by said rotary motion to lift a weight in response to said rotary motion from a first position to a second position and allow the weight to return to said first position under the influence of gravity. A rotary electrical is driven by the second system through a transmission means connected to the second system to create electricity only while the weight is returning from its second to its first position.

Abstract: A device and method for controlling the output of a wide speed range high reactance permanent magnet machine based PGS is provided. The windings of a permanent magnet machine are coupled to a three-phase diode bridge. A transistor is used for temporarily short-circuiting said diode bridge. A capacitor smoothes the voltage at a voltage detection point. A control unit generates a signal that switches the transistor in response to a voltage detected at the voltage detection point. The control unit signal modifies the duty cycle of the switching of the transistor in response to variations in the speed of the power generator to maintain a desired voltage at the voltage detection point.

Abstract: A magnet assembly includes a back iron and an array of magnets. The back iron is in the form of a plate having opposed surfaces. The magnets are arranged along one of the surfaces, with the other surface being dimensioned and configured according to the magnetic field distribution associated with the magnets. The back iron geometry provides for reduced mass, reduced leakage flux, and high flux densities to improve performance of a linear motor that employs such a magnet assembly.