Protective garments include a flame resistant fabric that is strong and yet has a soft hand. The fabric is made from a combination of filament yarns and spun yarns. The filament yarns and spun yarns are woven together such that the filament yarns are separated by from about 2 to about 5 spun yarns in both the warp direction and the fill direction. The spun yarns may contain polybenzimidazole fibers in combination with other fibers, such as aramid fibers. The filament yarns may comprise para-aramid fibers. In one embodiment, the filament yarns may have a size larger than the spun yarns.

Disclosed is a fabric for an airbag including a polyester fiber, and particularly to a polyester fabric for an airbag of which toughness is 3.5 to 6.0 kJ/m3 and tearing strength measured according to the ASTM D 2261 TONGUE method is 18 to 30 kgf, wherein the fabric includes polyester fiber of which toughness is 70 to 95 J/m3, a method of preparing the same, and an airbag for a car including the same.

High tenacity, high elongation multi-filament polymeric tapes as well as ballistic resistant fabrics, composites and articles made therefrom. The tapes are fabricated from multi-filament fibers/yarns that are twisted together, bonded together, compressed and flattened.

Provided are a lightweight, compact reinforcing tape capable of improving a tensile strength. A reinforcing tape for reinforcing a tensile strength of a cloth includes weft threads which constitute a weave structure of the reinforcing tape, and warp threads which constitute a weave structure of the reinforcing tape, wherein a part of the warp threads are made of a high-strength fiber.

Fabric strap having at least two different segments. The first segment is wider and less elastic, providing a comfortable contacting area to the skin and the other segment is narrower and more elastic which is aesthetically more pleasing and easier for applying sewing process in the garment production. Preferably, the first segment is a sealed tubular structure and contains internally free-floating yarns, making it exert less stress to the skin and thus more comfortable to the wearer. In addition, the different segments of the strap are made in a single integral weaving process and thus is conducive to industry automation.

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 device for manufacturing a fabric has a plurality of automatically working apparatus arranged next to one another on at least one carrier for manufacturing a leno weave (a leno weave apparatus). Two leno threads are fed to each leno weave apparatus. The device has at least one weft thread picking device; wherein the weft thread is introduced into the shed of leno threads raised by a plurality of leno weave apparatus. The weft thread is bound using at least two leno threads at a plurality of points behind the weft thread over the width of the fabric. At least one of the leno weave apparatus arranged in the end region of the fabric carries out a higher number of interlacings for achieving a homogenized warp tension distribution over the width of the fabric; and/or the lowering of the shed is carried out by the leno weave apparatus over the width of the fabric at different times for achieving a homogenized warp tension distribution.

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 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.

The connecting rod (6) for two articulations with parallel axes and for transmitting the rocking movements of an output lever of a shedding device to a heald frame belonging to a weaving loom, having a first connecting tip connecting to a first articulation and secured to a longitudinal bar, a second connecting tip (62) connecting to a second articulation and including members for clamping the bar that are accessible from one side of the connecting rod, and members (64) for separating the tips along a longitudinal axis (X6) of the connecting rod. The separating member having a bearing member (640) on an inclined surface (612; 630) whereof the normal is comprised in a plane (P6) perpendicular to the axes of the articulations and is inclined relative to the longitudinal axis (X6) of the connecting rod, while the bearing member (640) can be moved in a direction perpendicular to a plane (P34) containing the axes (X3, X4) of the articulations.

An airbag fabric, airbag and method for making the airbag fabric, the fabric consisting of warp and weft yarns of synthetic fiber yarn, characterized by satisfying the following requirements: (1) the total fineness of the synthetic fiber yarn is 100 to 700 dtex;(2) Nf/Nw≧1.10 wherein, Nw represents the weaving density of warp yarns (yarns/2.54 cm) andNf represents the weaving density of weft yarns (yarns/2.54 cm);(3) EC1≧400N and EC2≧400N wherein, EC1 represents the edgecomb resistance (N) in the machine direction, as determined according to ASTM D6479-02, andEC2 represents the edgecomb resistance (N) in the crosswise direction as determined according to ASTM D6479-02;(4) 0.85≦EC2/EC1≦1.15; and(5) the air permeability, as determined according to the Frajour type method specified in JIS L1096 at a test pressure difference of 19.6 kPa, is 1.0 L/cm2·min or less.

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.

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.

State based full and empty control for rechargeable batteries that will assure a uniform battery empty condition, even in the presence of a load on the battery. A fuel gauge provides a prediction of the open circuit voltage of the battery, and when the predicted open circuit voltage of the battery reaches the predetermined open circuit voltage of an empty battery, the load is terminated, after which the battery will relax back to the predetermined open circuit voltage of an empty battery. A similar technique is disclosed for battery charging, allowing faster battery charging without overcharging. Preferably an RC battery model is used as the fuel gauge to provide the prediction, but as an alternative, a coulomb counter may be used to provide the prediction, with error correction between successive charge discharge cycles.

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.

A disclosed battery protecting circuit includes a battery protecting IC powered by a voltage of a secondary battery; another battery protecting IC powered by a voltage of another secondary battery connected to the secondary battery in series; and a constant voltage output unit which receives a maximum voltage obtained by adding voltages of the secondary battery and the other secondary battery in series and outputs a constant voltage upon receipt of a control signal from an output terminal of the battery protecting IC or the other battery protecting IC.

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.

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.

A direct feeding apparatus for impedance matching of a wireless power transmission device includes a helical type resonator, and a feeding unit configured to directly feed power to a region having a relatively small current value as compared to a center of a conductive line of the resonator.

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 standby battery box for an electric cylinder is electrically connected to a control box for driving the electric cylinder and includes a charge-discharge device and a rechargeable battery. The charge-discharge device includes a protection unit, a power conversion unit, a voltage detection unit, a control unit, a discharge unit, a display unit, and a switch unit. The rechargeable battery is electrically connected to the charge-discharge device. When a startup switch of the switch unit is pressed, the charge-discharge device delivers the electricity of the rechargeable battery into the control box. When a shutoff switch of the switch unit is pressed, the charge-discharge device does not supply power, thereby protecting the standby battery box from being exhausted.

A battery system is disclosed. The battery system includes a plurality of battery cells, and a battery cell balancing unit, configured to adjust voltages across each of the battery cells to reduce variation among the voltages across the battery cells. The battery cell balancing unit includes a controller configured to receive a DC reference current and to generate an AC current based on the DC reference current, a transformer, a rectifier circuit including a rectifier connected to the output coil, and a switching unit including a plurality of switches, each configured to selectively connect the rectifier to one of the battery cells.

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.

A stand for a portable electronic device includes a device receiving side including a coupling component for engaging with the portable electronic device when the portable electronic device is in a first orientation relative to the device receiving side and when the portable electronic device is in a second orientation relative to the device receiving side. The stand also includes a first support side adjacent to the device receiving side to act as a base when the portable electronic device is in the first orientation, and a second support side adjacent to the first support side to act as a base when the portable electronic device is in the second orientation.

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 semiconductor device for battery control includes a CPU, a first bus coupled to the CPU, a second bus not coupled to the CPU, and a protective function circuit for protecting a battery from stress applied thereto. The semiconductor device also includes a non-volatile memory storing trimming data, a trimming circuit to perform trimming required to allow the protective function circuit to exert a protective function, and a bus control circuit capable of selectively coupling the first bus and the second bus to the non-volatile memory. The semiconductor device further includes a transfer logic circuit which causes, by making the bus control circuit select the second bus, a trimming data transfer path leading from the non-volatile memory to the trimming circuit to be formed and the trimming data stored in the non-volatile memory to be transferred to the trimming circuit without involving the CPU.

A battery pack and an electronic device are disclosed. The battery pack includes a battery for storing electric energy, and a non-contacting discharging unit for receiving the stored electric energy from the battery and for transferring the stored electric energy to a power receiving unit in a non-electrically contacting manner. The electronic device includes a main body and the battery pack. The main body includes a power receiving unit. The battery pack is for mounting to and supplying power to the main body.

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 charging device includes: capacitors connected in series; a charging unit that charges the capacitors; bypass units, each respectively connects in parallel to each capacitors, wherein each bypass unit causes, when a charged voltage of any capacitor has reached a set voltage, a charging current to bypass the capacitor whose charged voltage has reached the set voltage; and a control unit that controls the charging unit to charge the capacitors in such a manner that, when a charging voltage of the any capacitor has reached the set voltage, the control unit causes the charging unit to reduce the charging current, and if a predetermined period has elapsed since the charging voltage has reached the set voltage, and if a charging voltage of any of the other capacitors has not reached the set voltage after the predetermined period, the control unit causes the charging unit to increase the charging current.

An electricity generation device includes a permanent-magnet electric generator with three or more phase windings each having an output terminal and connected to a neutral point, and bidirectional semiconductor switching circuits capable of interrupting connections between the respective phase windings and the neutral point. Each switching circuit allows current to flow in both directions. A gate signal generation circuit outputs to one of the switching circuits during a period including the time at which the AC voltage excited in the corresponding phase winding turns from positive to negative and during a period including the time at which the AC voltage excited in the corresponding phase winding turns from negative to positive. A startup gate signal output circuit outputs a startup gate signal to all of the bidirectional semiconductor switching circuits when the permanent-magnet electric generator is to be started.

The present embodiments provide a control system and method that is able to automatically start and/or stop a portable engine-driven power source. For example, in one embodiment, a system includes an engine-driven power source having an engine, a compressor driven by the engine, a sensor configured to generate a first signal indicative of a demand for air pressure from the compressor and a second signal indicative of no demand for air pressure from the compressor. The engine-driven power source also includes a controller configured to stop the engine in response to the second signal.

The excitation overcurrent detection unit for the doubly-fed electric machine is provided with a function to determine an excitation current magnitude relationship among three phases. The firing pulse is held to on-state or off-state to cause the largest-current phase and the second-largest-current phase to charge the DC capacitor by the operation of diodes. The conduction ratio of the third-largest-current phase or minimum current phase is controlled according to the detected current value to protect against a possible short-circuit across the DC capacitor. When the voltage of the DC capacitor exceeds a preset value, the voltage is suppressed by operating active or passive power devices.