Abstract: A double fed induction generator (DFIG) converter, methods and computer readable mediums are presented in which rotor side current spikes are attenuated by selectively activating at least one series damping circuit to conduct current through a series damping circuit resistance coupled in series between one or more DFIG rotor leads and a grid side converter in response to a grid fault occurrence or a grid fault clearance, and selectively bypassing the series damping circuit resistance after activating the series damping circuit.

Abstract: A voltage regulator system for regulating an output voltage of a genset includes a voltage regulator for reducing terminal voltage in response to a reduction in terminal frequency. A plurality of under-frequency roll-off (UFRO) states is provided in the voltage regulator, with each UFRO state being configured to implement a UFRO characteristic. An operational signal indicative of an operating condition of the genset forms the basis for selection of the UFRO characteristic.

Abstract: An electronic power converter includes a storage circuit (101) capable of storing electrical energy that is determined by an electrical quantity, voltage or current, of the storage circuit. The electronic power converter includes an electronic power converter stage (102) connected to the storage circuit and a regulator (103) for controlling the electronic power converter stage to regulate the electrical quantity at least partly on the basis of deviation of the electrical quantity from its reference level. The regulator is configured to weight the deviation with a first gain coefficient when the deviation is positive, and to weight the deviation with a second gain coefficient when the deviation is negative. The first gain coefficient has a value different from that of the second gain coefficient because the reference level is typically not in the middle of the allowed range of variation of the electrical quantity.

Abstract: A control device for a hybrid vehicle has an engine, a starter motor that starts the engine, a driving motor that transmits a motor torque to the engine and a drive wheel, a starting motor selective control unit that starts the engine using the starter motor in response to a driving force request by a driver of the hybrid vehicle during a selected mode of operation in which the driving motor serves as the driving source, and that starts the engine using the driving motor in response to a system request.

Abstract: Systems and methods for controlling a renewable energy system based on actual reactive power capability of the renewable energy system are provided. The reactive power output of the renewable energy system can be controlled based at least in part on an initial reactive power limit. The initial reactive power limit can be determined based on rated reactive power for the power generation units in the renewable energy system. When a difference between a reactive power demand and the actual reactive power production of the renewable energy system fall outside a threshold, the initial reactive power limit can be adjusted to a corrected reactive power limit that is closer to the actual reactive power capability of the renewable energy system.

Abstract: A method for detecting a fault in an exciter circuit, suitable for use in a brushless generator, the exciter circuit including (a) an exciter armature winding, having a plurality of armatures, arranged to generate a multiphase AC signal, each armature of the plurality of armatures providing a respective sub-signal component of the multiphase AC signal, and (b) a rectifier circuit for receiving the sub-signals via the respective armatures, the rectifier circuit comprising a plurality of components arranged to rectify the sub-signals to provide a rectified output signal, wherein the method includes the steps of: acquiring a respective operational sub-value for a first characteristic of each of at least two of the respective sub-signals; deriving an operational value indicative of a relationship between the acquired respective operational sub-values; determining whether a fault has occurred in the exciter circuit on the basis of the derived operational value.

Abstract: A gas compressor includes a compressor unit having a compressor body for compressing gas and an electricity-generation device generating electricity by obtaining a driving force by vaporizing a working fluid utilizing exhaust heat generated by a compressing action in the compressor body and expanding the working fluid so as to utilize the power generated by the electricity-generation device as a power source, and includes a switch device switching between power from the electricity generation device and power from a commercial power supply to supply power to the power consumption equipment, and a control device detecting an electricity-generation amount or a value correlative to the electricity generation amount and switching between the powers by the switch device, thereby generating the power using exhaust heat as a heat source to surely drive an auxiliary machine by a simple configuration regardless of a shortage of the electricity generation amount.

Abstract: A closed-loop apparatus for converting mechanical energy into electrical energy utilizes a closed-loop channel including sections of different cross-section (including a first group of sections having a constrained cross-section and a second group sections having an enlarged cross-section). An energy-producing configuration (such as coils and/or electrodes) is formed to surround at least a portion of the channel. A closed-loop chain of energy-producing elements is positioned in channel such that when the chain moves along the channel, the mechanical motion generates electrical energy. The chain is formed to include a set of expandable assemblies that change in dimension as they pass through the different cross-section areas of the channel. An inert fluid is injected into the channel at one or more locations by a mechanical force, resulting in the creation of a pressure-induced force differential that initiates and maintains the movement of the chain with respect to the channel.

Abstract: An AC/DC conversion circuit of a power conversion apparatus receives an AC signal and has a switching element. A voltage sensing circuit generates a voltage reference signal according to an AC voltage signal. A harmonic generation circuit generates a harmonic injection signal according to the voltage reference signal. A subtraction circuit of a maximum power tracking circuit outputs a first DC signal and a second DC signal according to the voltage reference signal. An arithmetic circuit outputs a reference signal. A current sensing circuit outputs a feedforward signal according to one phase of an AC current signal. A current control circuit outputs an error signal according to the reference signal and the feedforward signal. A pulse width modulation circuit outputs a control signal to control the switching element according to the error signal and the harmonic injection signal, so that an aerogenerator operates at the maximum power approximation line.

Abstract: An energy harvesting apparatus is described that utilizes hydraulic actuation and creates a continuous, revolving motion of a chain of energy-producing elements within an energy-producing channel (the channel being in the form of a tube, for example). In particular, the arrangement of the present invention is based upon a specially-designed dual-loop channel topology that allows for efficient conversion of a unidirectional flow of a fluid entering the energy-producing channel into a smooth, continuous revolving motion of a chain of energy-producing elements within the channel.

Abstract: There is provided a control device for an internal combustion engine. An electricity generator is configured to be driven by the internal combustion engine. A battery is configured to store electricity generated by the electricity generator. A discharge amount detection section is configured to detect a discharge amount of the battery. An automatic stop control section is configured to automatically stop the internal combustion engine when the discharge amount is a first setting value or less. A continuous discharge amount detection section is configured to detect a continuous discharge amount of the battery based on the discharge amount. An automatic stop prohibition section is configured to prohibit an automatic stop when the continuous discharge amount is a second setting value or more, which is lower than the first setting value.

Abstract: A system for converting wind power to electrical energy has a peripheral frame, sails interconnected to the peripheral frame, radial struts extending from the hub to the peripheral frame, wheels mounted on the peripheral frame, electric generators interconnected with respective wheels, and a hub about which the peripheral frame is rotatable. The hub is in electrical communication with the electric generators. Sails may be interconnected with the peripheral frame on respective masts, each mast having a base and the mast being pivotable about the base. The electric generators may be mounted on a variety of locations, such as the peripheral frame. Each electric generator may be interconnected with a respective wheel via a belt, a chain or other mechanism. The system may include arrangements to generate electricity from sunlight.

Abstract: Systems and methods for reducing current imbalance between parallel bridge circuits used in a power converter of a doubly fed induction generator (DFIG) system are provided. A control system can monitor the bridge current of each of the bridge circuits coupled in parallel and generate a feedback signal indicative of the difference in bridge current between the parallel bridge circuits. Command signals for controlling the bridge circuits can then be developed based on the feedback signal to reduce current imbalance between the bridge circuits. For instance, the pulse width modulation of switching devices (e.g. IGBTs) used in the bridge circuits can be modified to reduce current imbalance between the parallel bridge circuits.

Abstract: A wind energy power conversion system includes a gearbox, a generator, an AC to DC power converter, a DC link, and a DC to AC power converter, and at least one ultracapacitor module connected in parallel on the DC link. A method of reducing stress on a wind turbine gearbox can be performed by obtaining an unwanted frequency of the wind energy power conversion system gearbox; determining an input torque value on the input shaft of the gearbox as a function of time; determining a frequency of the input torque value; and adjusting a torque on the output shaft of the gearbox based on the unwanted frequency.

Abstract: An electric power generation control apparatus is connected to an external controller composed of a vehicle interface circuit capable of generating and transferring a power switch-on signal to the electric power generation control apparatus. When receiving the power switch-on signal, the electric power generation control apparatus initiates its operation. The electric power generation control apparatus has a receiving terminal, a control signal receiving circuit, an electric power source circuit, and an electric power generation control circuit. The control signal receiving circuit receives the power switch-on signal through the receiving terminal regardless of the circuit type of the vehicle interface circuit. When the control signal receiving circuit receives the power switch-on signal, the electric power supply circuit initiates to supply the electric power to the electric power generation control circuit.

Abstract: A wind generator includes: a nacelle; a hub carried by the nacelle and including at least a pair of wind turbine blades; and an electricity producing generator including a stator and a rotor carried by the nacelle. The rotor is connected to the hub and rotatable in response to wind acting on the blades to rotate the rotor relative to the stator to generate electricity. A cooling system is carried by the nacelle and includes at least one ambient air inlet port opening through a surface of the nacelle downstream of the hub and blades, and a duct for flowing air from the inlet port in a generally upstream direction toward the hub and in cooling relation to the stator.

Abstract: A method for controlling power output of a wind turbine generator in response to an anticipated change in wind speed is provided. The method includes sensing wind speed at a desired distance from the wind turbine generator in a direction of the wind. The method further includes controlling pitch of a blade of the wind turbine generator based upon sensed transient wind speed in advance of a change in wind speed at the wind turbine generator.

Abstract: A hybrid blade wind turbine device formed of at least a pair of straight outer airfoil blades, and a pair of inner helical wing blades, as supported for rotation within a safety protective cage structure, which wind turbine can be mounted in the vertical, horizontal, or other aligned operational positions. The inner helical half wing blades, being preferably somewhat shorter than the length of the outer airfoil blades, act to “regularize” the swirling wind regime flowing through the hybrid wind turbine, so as to maximize the efficiency of the outer airfoil blades. The helical half wing blades can be formed of individual segmented vane segments to provide improved operational capabilities for the overall hybrid wind turbine. To best harness annualized available wind conditions, the hybrid wind turbine can be customized, through modification of the number of vane segments, the selection of the specific shape of the outer airfoil blades, and the specific operational positioning of the outer airfoil blades.

Abstract: An SMA device in which an SMA wire actuating element is operated periodically at a low voltage by power derived from a current source current which is too low to heat the wire directly sufficiently for effective actuation. The low current source is connected to a capacitor which discharges periodically through the SMA wire actuating element in response to an upper threshold charge stored by the capacitor thereby to periodically supply the SMA wire actuating element with a current level sufficiently high for effective operation. The discharge is effected through a signal amplifier formed by first and second transistors coupled to provide positive feedback and connected to a switch formed by a third transistor biased by output from the second transistor to periodically conduct, thereby permitting discharge of the capacitor through the SMA actuating element.

Abstract: A starter comprises a thermostat for detecting increases in the temperature of brushes and interrupting the energizing of the starter, and a heat conducting member secured to the thermostat for conducting the heat of one of the brushes, the heat conducting member being attached to the brush. The heat conducting member may also be formed integrally with a brush holder. The heat conducting member may additionally be secured to a bracket so as to hold a base therebetween. The heat conducting member may also be composed of a metallic material having superior thermal conductivity, and may be copper or brass. An electrically insulating sheet may be held between the brush holders and the base as heat insulating material for preventing the transfer of heat from the brushes to the base. An electrically insulating tube may also be interposed between the thermostat and a first leg of the heat conducting member.