A textile sleeve for routing and protecting elongate members and method of construction thereof is provided. The sleeve includes an elongate wall having opposite edges extending parallel to a central axis. The wall is woven with warp yarns extending parallel to the axis and hybrid fill yarns extending transversely to the warp yarns. The hybrid fill yarns are provided having a yarn filament core and non-metallic first and second yarn filaments overlying the yarn filament core. The first yarn filament is twisted about the yarn filament core in a first helical direction and the second multifilament yarn is twisted over the first yarn filament and about the yarn filament core in a second helical direction. The first helical direction and the second helical direction being opposite one another to provide a resultant zero torque on the yarn filament core.

An implantable graft device having treated yarn is disclosed. The device comprises a graft body forming a lumen defining a longitudinal axis and comprising proximal and distal ends. The graft body comprises a woven fabric having warp yarns aligned in a first direction and a weft yarns aligned in a second direction. At least one of the weft yarns and the warp yarns has an agent applied thereto defining treated yarns of the graft body.

A tuft carrier loading apparatus (10) for loading individual tufts (17) into tuft retention sites (9a) spaced along an elongate tuft carrier (9). The apparatus (10) includes a guide for guiding longitudinal movement of the tuft carrier along a path of travel and a plurality of individually and selectively operable tuft feeders (50) spaced along the path of travel, each tuft feeder (50) being operable when selected to feed an individual tuft to a tuft retention site (9a) of the tuft carrier (9). A driver (70) is drivingly connected to the tuft carrier (9) for moving the tuft carrier (9) along the path of travel, the driver (70) being operable to intermittently move the tuft carrier (9) through a series of successive positions whereat predefined tuft retention sites (9a) are moved temporarily into registry with each tuft feeder (50). A controller (60) is provided for controlling selection of the tuft feeders (50), the controller (60) being operable to actuate selected tuft feeders (50) to feed tufts to those tuft retention sites (9a) in registry therewith whilst the carrier (9) is located at each successive position. A detector is associated with each tuft retention site (9a) to detect the presence of a tuft. The driver (70), on detection of an absent tuft in a tuft retention site (9a) following actuation of one or more selected tuft feeders (50) resulting in failure to feed a tuft to the absent tuft retention site (9a), is operable to move the tuft carrier (9) into a position whereat the absent tuft retention site (9a) is moved temporarily back into registry with the or one selected tuft feeder (50) and the controller (60) re-actuates the selected tuft feeder (50) to feed a tuft to the absent tuft retention site (9a).

An anti-“Methicillin-Resistant Staphylococcus Aureus (MRSA)” chitosan containing antibacterial High Wet Modulus (HWM) rayon fiber textile for medical usage is made of the steps as following: chitin flakes made from natural shrimp or crab shells are deacetylated to generate chitosan with a high deacetylation degree of 90% or more. Next chitosan is dissolved in acetic acid and regenerated by caustic soda to form a chitosan antibacterial nanoparticles slurry, then added to HWM viscose rayon process, and spinning to produce a chitosan containing antibacterial HWM rayon fiber. The antibacterial amino groups of chitosan and the hydroxyl groups of rayon cellulose combine together via hydrogen bonding. Therefore, the fiber becomes the anti-MRSA antibacterial HWM rayon fiber containing amino groups (—NH3+). Finally the resulting HWM rayon fiber is conducted via a yarn spinning or/and weaving process to procure a medical textile with chitosan content.

An X weave of composite material has multiple latitudinal fibers, multiple longitudinal fibers, and a woven center. Each longitudinal fiber is layered on two of the latitudinal fibers and then is woven through and layered under two of the latitudinal fibers. The longitudinal fibers are each woven by shifting in relative alignment position from one of the latitudinal fibers sequentially and woven radially with respect to the woven center, such that the longitudinal fibers form an X woven structure. Therefore, the intensity of the X weave can be enhanced by the X woven structure.

A textile sleeve for routing and protecting elongate members and method of construction thereof is provided. The sleeve includes an elongate wall having opposite edges extending parallel to a central axis of the sleeve. The wall is woven with warp yarns extending parallel to the axis and fill yarns extending transverse to the warp yarns. The warp yarns include monofilament yarns within an intermediate region of the wall and multifilament yarns within opposite edge regions of the wall to enhance abrasion resistance and curl, respectively, and the fill yarns include monofilament yarns larger in diameter than the fill monofilament yarns to provide further abrasion resistance, enhanced curl strength and multifilament yarns to provide increased coverage, maintain flexibility, and to maintain the warp monofilaments in their intended position.

A method weaves pile fabrics with at least two different pile heights (a, b) in the same pile row, wherein the fabrics have weft threads, ground warp threads and pile-warp threads (1, 2), wherein these pile-warp threads are interlaced in the fabric, according to a pattern, in a figure-forming manner or are inwoven in a non-figure-forming manner, and which, when they are figure-forming, form pile with a well-defined pile height. The method includes a first set of pile warp threads, under light strain and at least a second set of pile warp threads under a higher strain. A device for manufacturing such fabrics is described.

The loom includes a weaving area (18) into which weft threads are inserted into at least one upper channel and one lower channel, each of these weft threads being inserted between at least two warp threads by at least one weft insertion element: first element for focusing on one of these channels and determining the position of the warp threads relative to the weft thread, and second element for inserting at least one binding thread (16) above, between and below these channels. The loom includes at least one element for gripping the at least one binding thread and element for moving the at least one gripping element out of and into the weaving area (18) so as to place the at least one gripping element in contact with the at least one binding thread and to allow the drawing of the at least one binding thread.

A three-dimensional woven fabric including front layer, rear layer, and light-shielding layer connecting front layer to rear layer and a method thereof are disclosed. The light-shielding layer is formed by repeatedly overlapping first, second, and third light-shielding layers with another light-shielding layer with adjacent ones among the first to the third light-shielding layers overlapped. The front layer includes front parts formed by weaving front layer wrap threads and weft threads, the front parts have front layer-connecting parts formed by sequentially and repeatedly weaving front layer wrapwrap threads and weft threads and light-shielding layer wrap threads, the rear layer includes rear layer-connecting parts formed by weaving sequentially and repeatedly the rear layer wrap threads and weft threads and light-shielding layer wrap threads. The light-shielding layers are formed by weaving light-shielding layer wrap threads and the weft threads, and the light-shielding layers are sequentially and repeatedly connected to front layer-connecting parts and rear layer-connecting parts. Three-dimensional shapes are implemented without adhesive. Various designs and light-shielding control are available.

This lanyard, which is movable by elasticity between a rest position and a stretched position, comprises a tubular sheath made from non-stretchable material, and a set of elastic threads joined to the sheath. According to the invention, the elastic threads define at least one longitudinal weaving zone in which they are woven on one surface of the sheath only, each weaving zone being proper to form a bending zone of the lanyard, in the rest position, in which the elastic threads are folded onto themselves.

A three dimensional woven preform, a fiber reinforced composite incorporating the preform, and methods of making thereof are disclosed. The woven preform includes one or more layers of a warp steered fabric. A portion of the warp steered fabric is compressed into a mold to form an upstanding leg. The preform includes the upstanding leg and a joggle in a body portion. The body portion and upstanding leg are integrally woven so there is continuous fiber across the preform. A portion of the warp steered fabric includes stretch broken carbon fibers in the warp direction, and another portion includes conventional carbon fibers. The warp steered fabric can be woven on a loom equipped with a differential take-up mechanism. The warp steered fabric can be a single or multilayer fabric. The preform or the composite can be a portion of an aircraft window frame.

A multilayer textile sleeve and method of construction thereof is provided. The sleeve has an outer layer constructed at least in part from a first warp yarn extending along a length direction of the sleeve and a weft yarn extending transversely to the length direction. The sleeve further includes an inner layer constructed at least in part from a second warp yarn extending along the length direction and a weft yarn extending transversely to the length direction, with the second warp yarn being a different type of yarn than the first warp yarn. The outer layer and inner layer are connected to one another by interlinking the weft yarn of the outer layer with at least some of the second warp yarns of the inner layer and by interlinking the weft yarn of the inner layer with at least some of the first warp yarns of the outer layer.

Systems and methods for controlling the output of a battery pack are disclosed. In one example, a battery pack contactor is opened in response to battery pack current. The system and method may reduce battery pack degradation and increase system flexibility.

In a method for transferring energy between at least two energy storage cells in a controllable energy store that serves to control and to supply electrical energy to an n-phase electric machine, which energy store has n power supply arms which each have at least two series-connected energy storage modules which each include at least one electrical energy storage cell with an associated controllable coupling unit, and are connected to one respective phase of the electric machine, in a charging phase, all coupling units of those energy storage modules which are to be used as an energy source are controlled in such a way that the respectively associated energy storage cells are connected into the respective power supply arm.

A method for charging an assembled battery including series circuits connected in parallel, each of the series circuits including series-connected lead storage batteries, using a single charger is provided. The method includes: a first step of obtaining a first index value, corresponding to a resistance value of a first series circuit with a correlative relationship, the first series circuit having a lowest resistance value; a second step of obtaining a second index value corresponding to a resistance value of a second series circuit with a correlative relationship, the second series circuit having a highest resistance value; a third step of performing normal charging, in which the assembled battery is charged with a first amount of charge corresponding to the first index value; and a fourth step of performing refresh charging, in which the assembled battery is charged with a second amount of charge corresponding to the second index value.

A battery pack, and a method of controlling the battery pack are disclosed. The battery pack detects consumption current when a load is not turned on, and shuts off power when a load is turned off or in stand-by mode, thereby preventing consumption current of the load from flowing.

The present inventions, in one aspect, are directed to techniques and/or circuitry to adapt the charging of a battery using data which is representative of an overpotential or relaxation time (full or partial) of the battery. In another aspect the present inventions are directed to techniques and/or circuitry to calculate data which is representative of an overpotential or relaxation time (full or partial) of the battery. In yet another aspect the present inventions are directed to techniques and/or circuitry to calculate data which is representative of a state of charge of the battery using an overpotential or relaxation time (full or partial) of the battery.

Circuitry and techniques to measure, at the battery's terminals, characteristic(s) of the charging signal applied to the battery/cell during the recharging operation and, in response to feedback data which indicates the charging signal is out-of-specification, control or instruct the charging circuitry to adjust characteristic(s) of the recharging signal (e.g., the amplitude of the voltage of and/or current applied to or removed from the battery during the charging operation). For example, a rechargeable battery pack comprising a battery, and controllable switch(es), a current meter and voltmeter, all of which are fixed to the battery. Control circuitry generates control signal(s) to adjust a current and/or voltage of the charging signal using the feedback data from the current meter and/or voltmeter, respectively.

A method for operating a driverless, mobile assembly and/or material transport unit as a driverless transport system (DTS) with fixed assembly and/or warehousing stations. In this method, a system control device is used for the entire assembly process. The driverless, mobile assembly and/or material transport units comprises a travel device for the traveling movement of the unit, a drive device for the travel device, an energy storage device for providing the energy for the drive device and a control device for controlling the traveling movement in coordination with the system control device.

A system for detecting a short-circuited ultracapacitor cell in a machine is disclosed. The system may have a memory that stores instructions and one or more processors capable of executing the instructions. The one or more processors may be configured to perform cell balancing among ultracapacitor cells arranged within two or more ultracapacitor modules, each ultracapacitor module including at least two ultracapacitor cells connected in series. The one or more processors may be further configured to measure a module voltage generated by each of the plurality of ultracapacitor modules after performing the cell balancing and before applying a load of the machine to the ultracapacitor modules, and determine whether an ultracapacitor cell among the plurality of ultracapacitor cells is short-circuited based on a comparison of the measured module voltages.

Systems and methods to determine cell capacities of a vehicle battery pack. Cell capacities may be determined using state of charge (SOC) estimates for the cells and a charge count for the battery pack. The SOC estimates may be determined when the SOC of the battery pack is below a lower threshold and above an upper threshold. Error values may also be generated for the cell capacity values.

A method for electrically charging a high-voltage battery of a subject vehicle includes resolving a geographic location of the subject vehicle at a remote charging site, electrically charging the high-voltage battery through a connection of the subject vehicle to an electric power outlet at the remote charging site, monitoring cumulative electric power flow to the high-voltage battery of the subject vehicle, communicating the cumulative electric power flow to a central server, and reconciling billing for the cumulative electric power flow between an owner of the subject vehicle and an owner of the remote charging site.

According to an embodiment of the present invention, a recharging device includes a recharging port that receives a flameless candle and recharges a battery in the candle. The recharging device includes a first stacking structure that has a top portion and a bottom portion. There is a top stacking contact on the top portion. An electrical power bus is connected with the top stacking contact. The electrical power bus is also configured to provide electrical power to the flameless candle through the recharging port. The top portion of the first stacking structure is configured to mate with a bottom portion of a first stacking structure of another recharging device.

Systems and methods for in-vehicle charging of pallet jack batteries are provided. An example system allows using a power source of a host vehicle configured to provide power at voltage levels lower than the operating voltage of the pallet jack battery stack. The system may allow, for example, charging a 24 volts pallet jack battery stack from a 12 volts power source of the host vehicle. The system may further comprise an interconnecting circuit having a plurality of contactors electrically coupling the batteries in parallel for charging and serially for discharging. The system may further comprise a voltage monitoring circuit to detect whether the pallet jack is connected to the host vehicle power source for charging. Based on the detection, the voltage monitoring circuit may reconfigure the interconnecting circuit to electrically couple the pallet jack batteries in parallel.

A system for protecting a power consuming circuit, the system comprising two terminals for receiving power and two terminals for providing received power. Between one of the receiving terminals and a providing terminal, a transistor is provided which is controlled by a Zener diode and to break the connection between one of the receiving terminals and a providing terminal, if a voltage over the providing terminals or the receiving terminals exceeds the breakdown voltage of the Zener diode.

A charging apparatus including a charging unit adapted to charge, in a non-contact manner, an apparatus to be charged placed in a charging region, a detector adapted to detect a charged state of the apparatus to be charged placed in the charging region, and a controller adapted to change a mode of the apparatus to be charged to a mode that inhibits vibration, according to the charged state detected by the detector.

An electric power supply system includes a connecting device that connects a secondary battery provided in a vehicle to a building, and a control apparatus that i) identifies the type of the vehicle that is connected to the connecting device, the type of the secondary battery, or the type of electric power that is distinguishable by the charging source of the electric power stored in the secondary battery, ii) determines a preset electric power supply method based on the identification results, and iii) controls a supply of electric power from the secondary battery to the building based on the determined electric power supply method.

A method for scheduling a charge of a plug-in electric vehicle (PEV) includes receiving, by a load management system, PEV information from a PEV plugged into an electric vehicle supply equipment (EVSE); transformer information from a transformer management system, the transformer information relating to a transformer associated with the EVSE; determining, by the charging information based on the PEV information and transformer information; providing the charging information to the PEV.

An energy storage system and a method of controlling the same is provided. The energy storage system may directly provide generated DC power or DC power stored in a battery to a DC load without performing a DC/AC conversion or an AC/DC conversion. Furthermore, in the case where a grid operates abnormally (e.g. power interruption) and the energy storage system functions as an uninterruptible power supply (UPS), power stored in a battery may be selectively provided to loads according to power remaining in a battery, and thus stored power may be used stably.

There is provided a battery controller including a storing unit which stores an upper limit voltage and a lower limit voltage, each defining a first voltage range in which a battery is charged/discharged, and a second upper limit voltage and a second lower limit voltage, each defining a second voltage range which is wider than the first voltage range, and a charge/discharge regulation unit which temporarily changes, when charge/discharge is performed in the first voltage range and permission for charge/discharge in the second voltage is received, setting of the battery such that charge/discharge is performed in the second voltage range.

A discharge device actively discharges a main capacitor in an electric-power system of an electric-drive vehicle and comprises a discharge branch of a circuit connected in parallel to the capacitor and including a discharge transistor biased to “conduction” mode when the capacitor must be discharged. A control device is connected to a “gate/base” terminal of and controls the transistor, biasing the transistor to the mode when the capacitor is required to fee discharged. A control transistor maintains the discharge transistor in a “non-conductive” state when the control transistor is in the mode. The control transistor is in the state for the discharge transistor to be in the mode. A safety capacitor is interposed between the terminal and a power supply and charges when the discharge transistor is in the mode, causing a progressive decrease of current at the terminal, until the discharge transistor is biased to the state.

There is provided a battery module including: a power storage unit storing power; a first authentication unit carrying out first authentication via a first authentication route; a second authentication unit carrying out second authentication via a second authentication route; and a discharging control unit controlling discharging from the power storage unit to an external appliance, wherein the first authentication unit is operable, when the first authentication has succeeded, to share key information to be used in the second authentication with an authentication party for the second authentication, the second authentication unit carries out the second authentication using the key information shared with the authentication party, and the discharging control unit is operable, when the second authentication has succeeded, to permit discharging from the power storage unit.

A method includes steps of dividing resistance R into a physical and chemical resistances Ro and Rp, obtaining corrected open-circuit voltages Vo corresponding to setting currents Ia to Ix, acquiring predicted reaching voltages Va to Vx corresponding to the setting currents Ia to Ix, and creating a current-voltage curve. The corrected open-circuit voltages Vo are obtained to predict available maximum currents I—target in a particular time t2. The predicted reaching voltages Va to Vx are acquired based on corrected physical and chemical resistances Ro and Rp, and the corrected open-circuit voltages Vo. The current-voltage curve is creased based on the setting currents Ia to Ix and the predicted reaching voltages Va to Vx to acquire upper and lower limit voltages Vmax and Vmin, and upper and lower limit currents Imax and Imin at a temperature whereby assigning these limit currents to available maximum currents I—target in charging and discharging operations, respectively.

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.

A wind power generator generates power through a rotation of a rotor and is interconnected, and operated with its power generation output previously limited in order to be able to further supply the power to a power system in response to a decrease in system frequency. Thus, a concentrated control system derives a required restricted amount corresponding to a power generation output required to respond to the decrease in system frequency, derives a value by subtracting an amount corresponding to a latent power generation output with which the power generation output can be increased, from the required restricted amount, and sets a restricted amount of the power generation output in each wind power generator to perform the operation with the power generation output previously limited to respond to the decrease in system frequency, based on the above value.

The present invention provides a method and a device for primary frequency regulation based on bang-bang control, the method comprises: obtaining in real-time a power grid frequency of a steam turbine generator set; performing a subtraction operation on a rated power grid frequency and said power grid frequency to generate a power grid frequency difference; performing a dead zone process on the power grid frequency difference according to a dead zone fixed value to generate a frequency difference; performing a frequency difference compensation operation on the frequency difference to generate a frequency difference compensation instruction; and combining an original primary frequency regulation output instruction with the frequency difference compensation instruction and outputting the result to a steam turbine speed regulation system when a selecting switch is 1.

A generator airgap monitoring system includes a first proximity sensor disposed in a first location of a stator and configured to transmit a first signal representative of a first distance between the first proximity sensor and a plurality of rotor poles of a rotor, and a controller communicatively coupled to the first proximity sensor. The controller is configured to derive a first plurality of instantaneous airgaps based on the first signal and to determine a difference between a first instantaneous airgap of the first plurality of instantaneous airgaps and a second instantaneous airgap of the first plurality of instantaneous airgaps. The first plurality of instantaneous airgaps includes a first plurality of measurements of airgaps between the stator and the plurality of rotor poles when the rotor is rotating. The first instantaneous airgap and the second instantaneous airgaps include measurements for respective rotor poles.

The control system of this floating wind turbine generator is a control system of a floating wind turbine generator in which the control system controls a pitch angle control section by a pitch angle instruction value calculated on the basis of signals detected by a second sensor detecting a relative angle between a nacelle and a tower and a third sensor detecting a yaw angle from a reference position of the tower so that a signal detected by a first sensor detecting wind direction deviation relative to a vertical direction of a rotation plane of wind turbine blades indicates an angle within a predetermined range from the vertical direction of the rotation plane of the wind turbine blades, and controls a yaw driving device by a yaw driving instruction value calculated on the basis of the signals detected by the second sensor and the third sensor.

A DC chopper comprising a control unit and a power circuit and a DC chopping method for a DFIG (doubly fed induction generator) system are provided. The input terminal of the control unit is coupled to a DC capacitor of a converter to detect a DC voltage. The power circuit includes input terminals, an overvoltage protection module, a rectifier module and output terminals. The overvoltage protection module comprises at least one discharge unit formed from a discharge resistor and a switch element, and the rectifier module is coupled in parallel to the overvoltage protection module. When a grid voltage drops, the control unit outputs a corresponding control signal to drive the switch element to be ON or OFF, and the output terminal of the power circuit absorbs a portion of rotor inrush current, so as to impose over-current protection.

An integrated power system suitable for simultaneously powering marine propulsion and service loads. The system includes: (a) at least one generator configured with at least first and second armature windings configured to output respective first and second alternating current power signals of different voltages, the at least two armature windings positioned within the same stator slots so that they magnetically couple; (b) at least first and second rectifier circuits coupled to said generator to convert said first and second alternating current power signals into first and second direct current power signals; and (c) a first load to which said first direct current power signal is coupled and a second load to which said second direct current power signal is coupled.

A method for converting heat to electric energy is described which involves thermally cycling an electrically polarizable material sandwiched between electrodes. The material is heated by extracting thermal energy from a gas to condense the gas into a liquid and transferring the thermal energy to the electrically polarizable material. An apparatus is also described which includes an electrically polarizable material sandwiched between electrodes and a heat exchanger for heating the material in thermal communication with a heat source, wherein the heat source is a condenser. An apparatus is also described which comprises a chamber, one or more conduits inside the chamber for conveying a cooling fluid and an electrically polarizable material sandwiched between electrodes on an outer surface of the conduit. A gas introduced into the chamber condenses on the conduits and thermal energy is thereby transferred from the gas to the electrically polarizable material.

This invention is directed to a system that generates a sufficient level of electricity through access to a municipal water supply line to run a furnace during below freezing temperatures. The system includes an inlet that draws water from a water supply line. A first conduit, in communication with the inlet, transports the water into a DC generator that includes an impeller to generate electricity. Water is then routed through a second conduit which then returns the water to the water supply line through an outlet. A solenoid valve may be positioned between the inlet and first conduit which remains closed when the electric grid runs normally but will open during a power outage to supply water to the DC generator. A lithium battery stores power created by the DC generator, which may include a voltage regulator and inverter to convert to DC.

Some embodiments relate to a method of controlling speed of a variable speed generator. The method includes detecting a load of the variable speed generator and determining a target speed for the variable speed generator based on the load supplied by the variable speed generator. The method further includes using a controller to adjust the speed of the variable speed generator based on the target speed. The method may further include correcting the target speed by calculating a correction factor that corrects the target speed based on a voltage produced by the variable speed generator.

A dip in the output voltage of a motor-vehicle alternator, owing to a connecting of a load or a change in speed, is compensated with the aid of an alternator regulator which provides a control signal that has a duty factor and increases the excitation current of the motor-vehicle alternator. After the occurrence of the voltage dip, in a first step, the duty factor of the control signal is increased by a differential amount, and in a subsequent second step, the rate of correction is limited. After the occurrence of the voltage dip, parameters describing the instantaneous working point of the motor-vehicle alternator are determined, and in the first step, the differential amount is set as a function of the working point.

Systems and methods for monitoring excitation of a generator based on a faulty status of a generator breaker are provided. According to one embodiment, a system may include a controller and a processor communicatively coupled to the controller. The processor may be configured to receive, from a contact associated with a generator breaker, a reported status of the generator breaker, receive operational data associated with one or more parameters of a generator associated with the generator breaker, and correlate the reported status of the generator breaker and the operational data. Based on the correlation, the processor may establish an actual status of the generator breaker, and, based on the actual status, selectively modify a mode of excitation of the generator.

According to an embodiment, a method of operating a wind turbine comprising a DC-to-AC voltage converter is provided, the wind turbine being connectable to a grid via the DC-to-AC voltage converter, the method comprising: determining a line voltage of a power line connecting the DC-to-AC voltage converter to the grid; if the determined line voltage exceeds a predefined voltage threshold value, injecting reactive current into the power line, wherein the amount of reactive current injected is chosen such that an output voltage of the DC-to-AC voltage converter is kept within a predetermined voltage range.

A generator system includes a generator having a stationary portion and a rotating portion. An exciter field winding and a main armature winding are disposed on the stationary portion. An exciter armature winding and a main field winding are disposed on the rotating portion. A frequency demodulator is configured to extract a frequency modulated control signal from the exciter armature winding and to demodulate the frequency modulated control signal to generate a demodulated control signal. The generator includes a main field rotating power converter to selectively control current in the main field winding in response to the demodulated command signal. The generator system includes a generator control unit in electrical communication with the generator to monitor the output voltage at the main armature winding and to output an exciter current including the frequency modulated control signal to the exciter field winding based on the output voltage.

A method for converting heat to electric energy is described which involves thermally cycling an electrically polarizable material sandwiched between electrodes. The material is heated using thermal energy obtained from: a combustion reaction; solar energy; a nuclear reaction; ocean water; geothermal energy; or thermal energy recovered from an industrial process. An apparatus is also described which includes an electrically polarizable material sandwiched between electrodes and a heat exchanger for heating the material. The heat source used to heat the material can be: a combustion apparatus; a solar thermal collector; or a component of a furnace exhaust device. Alternatively, the heat exchanger can be a device for extracting thermal energy from the earth, the sun, ocean water, an industrial process, a combustion reaction or a nuclear reaction. A vehicle is also described which comprises an apparatus for converting heat to electrical energy connected to an electric motor.

A method of operating a converter of a wind turbine for providing electric energy to a utility grid includes determining a grid voltage. If the grid voltage is between a nominal voltage and a first voltage threshold, i.e. higher than the nominal voltage, a normal procedure for lowering the grid voltage is performed. If the grid voltage is above the first voltage threshold, another procedure for keeping the wind turbine connected is performed, wherein the other procedure is different from the normal procedure. Further a corresponding arrangement is described.

The present invention discloses a method and an apparatus for power control. An apparatus for power control in accordance with an embodiment of the present invention can include: a voltage comparing part configured to compute an error voltage by using a measured voltage measured at the generator and a reference voltage that is designated; a control module configured to compute a first reactive power value for power control of the generator by being inputted with the error voltage; and a driving module configured to compute a reference reactive power value by using the first reactive power value and a second reactive power value computed using an active power value of the power converter and configured to control the power converter in correspondence with the computed reference reactive power value.