Abstract: An uninterruptible power supply device includes: a converter that converts AC power supplied from an AC power supply into DC power and outputs the DC power to a first power supply node; a first bidirectional chopper that outputs DC power in a lead storage device to the first power supply node when the AC power supply has a power failure; a diode connected between the first power supply node and a second power supply node; a second bidirectional chopper that supplies and receives DC power between the second power supply node and a lithium ion battery; and a controller that controls the second bidirectional chopper to charge the lithium ion battery during regenerative operation of a load and to discharge the lithium ion battery during power running operation of the load.

Abstract: An element module includes a cooler, a plurality of elements, and a conductive member. The cooler includes a first element disposition portion and a second element disposition portion which are provided on both sides in a predetermined direction. The plurality of elements are disposed in each of the first element disposition portion and the second element disposition portion. The conductive member is disposed in a space portion of the cooler. The space portion penetrates the cooler between the plurality of elements in each of the first element disposition portion and the second element disposition portion. The space portion allows the first element disposition portion and the second element disposition portion to communicate with each other. The conductive member is connected to the element of the first element disposition portion and the element of the second element disposition portion.

Abstract: A power conversion device includes: a power conversion circuit for converting DC power into AC power; and a controller to generate a control signal for the power conversion circuit based on a control command value and an output voltage of the power conversion circuit. The controller is configured to generate the control signal based on a corrected voltage command value calculated by subtraction correction to decrease a voltage command value when the output voltage of the power conversion circuit is equal to or higher than a predetermined threshold value, and to generate the control signal based on a voltage command value not subjected to the subtraction correction when the output voltage of the power conversion circuit is lower than the threshold value.

Abstract: The uninterruptible power supply device includes a switch (2) that includes first to Nth IGBT units (U1 to UN) connected in series, and a controller that turns on the switch by turning on the first to Nth IGBT units, and turns off the switch by firstly turning off the first to nth IGBT units and then turning off the (n+1)th to Nth IGBT units. Compared with the case where the first to Nth IGBT units are turned off at the same time, it is possible to reduce a surge voltage generated between the terminals of the switch (2).

Abstract: A power conversion device includes a three-level inverter circuit and an inverter control circuit for driving the three-level inverter circuit in a double carrier modulation manner. The inverter control circuit includes a command value calculating part generating three-phase output voltage command values, a command value correcting part outputting corrected command values by correcting to the three-phase output voltage command value, and a gate signal generating part generating a gate signal based on the corrected command values. The command value correcting part is configured to output a predetermined voltage command value corresponding to an end of a dead band instead of one AC voltage command value, and distribute a difference between the one AC voltage command value and the predetermined voltage command value in the dead band passage period to other two AC voltage command values, during a dead band passage period.

Abstract: An edge drop control device calculates a first calculated manipulated amount of a work roll shift device for bringing a difference between a measured edge drop amount and a target amount close to zero without using a work roll bender device. The edge drop control device calculates a second calculated manipulated amount of the work roll bender device for bringing a difference between a measured edge drop amount and the target amount close to zero without using a work roll shift device. The edge drop control device outputs, when the first calculated manipulated amount is out of an allowable range, the second calculated manipulated amount to the work roll bender device and also outputs a difference between an amount that corresponds to the second calculated manipulated amount and the first calculated manipulated amount, to the work roll shift device.

Abstract: An open phase detection system for a power conversion system includes a phase difference abnormality detection unit, an amplitude difference abnormality detection unit, and an open phase determination unit. The phase difference abnormality detection unit outputs a phase difference abnormality signal when an absolute value of a phase difference between a current flowing through a reactor and a current flowing through a capacitor is equal to or smaller than a phase threshold value. The amplitude difference abnormality detection unit outputs an amplitude difference abnormality signal when an absolute value of a value based on an amplitude difference between the current flowing through the reactor and the current flowing through the capacitor is equal to or smaller than an amplitude threshold value. The open phase determination unit outputs an open phase signal when receiving inputs of both the phase difference abnormality signal and amplitude difference abnormality signal.

Abstract: A voltage controller generates an AC current command value by adding a feed-forward term to a result of a control calculation performed for reducing a difference of a detected value of an AC voltage with respect to an AC voltage command value, the feed-forward term being determined by multiplying, by a gain, a detected value of primary winding current of a transformer. A current controller generates an inverter control command value by a control calculation performed for reducing a difference of a detected value of output current of the inverter with respect to the AC current command value. A PWM circuit generates a control signal for the inverter by comparing the inverter control command value with a predetermined carrier wave. When exciting inrush current is detected in a detected value of the primary winding current, the voltage controller sets the gain smaller than the gain when the exciting inrush current is not detected.

Abstract: A power conversion device in an embodiment includes a first power converter; a plurality of direct current-direct current (DCDC) converter devices; and a second power converter. The first power converter includes a plurality of first positive-side arms; a plurality of first negative-side arms; a first positive-side star connection line configured to connect the plurality of first positive-side arms in a star shape; a first negative-side star connection line configured to connect the plurality of first negative-side arms in a star shape; and a first terminal configured to connect the first positive-side star connection line and the first negative-side star connection line to each phase of a power supply side alternating current (AC) system and the plurality of first positive-side arms and the plurality of first negative-side arms mutually convert a first AC power and a first DC power of the power supply side AC system.

Abstract: A multiple power conversion system includes a plurality of first to n-th unit power converters. DC positive sides of the plurality of unit power converters are connected to one another, DC negative sides of the plurality of unit power converters are connected to one another, and n is an integer of two or more. The multiple power conversion system further includes a detector to detect a current flowing through the DC positive side or the DC negative side of a corresponding one of (n?1) or more of the plurality of unit power converters. The multiple power conversion system that can detect a circulating current with a smaller number of current sensors.

Abstract: A power conversion device includes: a three-phase inverter including a plurality of switching elements; and a controller configured to PWM-control the three-phase inverter based on three phase voltage commands. The controller generates a zero-phase voltage command using a two-phase modulation scheme and a third harmonic component of the three phase voltage commands. The controller adds the generated zero-phase voltage command to each of the three phase voltage commands to thereby correct each of the three phase voltage commands. The controller compares each of the corrected three phase voltage commands with a carrier wave, to thereby generate a control signal for controlling switching of the plurality of switching elements.

Abstract: A power system includes an AC power supply, an AC filter circuit, an AC circuit breaker, and a first switch. The AC filter circuit includes an inductor having one end connected in series to an output end of the AC power supply, and a capacitor having one end receiving a voltage at another end of the inductor. The AC circuit breaker exists between the other end of the inductor and an electric power grid. The first switch switches a state between the one end of the capacitor and a wire connecting the other end of the inductor to the AC circuit breaker, between a connected state and a disconnected state. The AC power supply may be a generator and include a generator control unit controlling the generator. The generator control unit may turn off the first switch when the AC power supply operates in a predetermined standby mode.

Abstract: In a thyristor starter, an inverter converts DC power provided from a converter through a DC reactor into AC power having a variable frequency, and supplies the AC power to a synchronous machine. A controller controls the inverter based on a phase control angle. A voltage regulator regulates an induced voltage of the synchronous machine by supplying a field current to the synchronous machine. When a rotation speed of the synchronous machine exceeds a reference rotation speed during acceleration of the synchronous machine, the voltage regulator controls the field current such that the induced voltage increases with an increase in the rotation speed of the synchronous machine. The controller decreases a rate of increase in the phase control angle relative to the rotation speed of the synchronous machine, as compared with when the rotation speed of the synchronous machine is less than the reference rotation speed.

Abstract: An electrical power system includes: a solar battery panel; a first electrical power conversion device; a secondary battery; and a second electrical power conversion device. The first electrical power conversion device and the second electrical power conversion device selectively execute a first mode in which the first electrical power conversion device performs MPPT control on the solar battery panel and the second electrical power conversion device performs the charging-discharging control and a second mode in which the first electrical power conversion device performs output limit control to restrict output electrical power from exceeding a predetermined output limiter value and the second electrical power conversion device performs MPPT control on the solar battery panel.

Abstract: In a power converter, a first single-phase AC conversion unit, which is connected to a first line of a first phase and a second line of a second phase of a first three-phase AC, a second single-phase AC conversion unit, which is connected to the second line of the second phase and a third line of a third phase of the first three-phase AC, and a third single-phase AC conversion unit, which is connected to the third line of the third phase and the first line of the first phase of the first three-phase AC, form a delta-connected load for an AC power supply system. At least the first single-phase AC conversion unit, the second single-phase AC conversion unit, and the third single-phase AC conversion unit form a first set in which respective output terminals are connected in series to one another, and the first set, and a second set and a third set, which are different from the first set, form each phase of a star connected power supply.

Abstract: An uninterruptible power supply device includes a switch, a power converter, and another power converter. The switch includes a first electrode that receives AC power from an AC power supply and a second electrode connected to a load via an AC bus, and is turned on during a normal operation and turned off during a power failure. The power converter converts DC power from a DC power supply into AC power and outputs it to the AC bus during a power failure. The other power converter converts the AC power received from the AC bus into DC power and stores it in a lithium-ion battery when the load is performing regeneration running, and converts the DC power of the lithium-ion battery into AC power and supplies it to the AC bus when the load is performing power running.

Abstract: A multiplex power conversion system enabling preventing a failure from spreading, with a simple configuration. The multiplex power conversion system includes a plurality of unit power converters. In the plurality of unit power converters, respective direct-current positive sides are connected. Respective direct-current negative sides are connected. Respective direct-current neutral points are not short-circuited. For example, the respective direct-current neutral points are not connected. Therefore, a failure in a power converter can be prevented from spreading.

Abstract: A master controller controls a plurality of uninterruptible power supply apparatuses each including a slave controller and detection circuits that detect at least a DC input voltage, an AC output voltage, and an output current of an inverter. The master controller generates a first voltage command value and a second voltage command value common to the plurality of uninterruptible power supply apparatuses based on detection values from the detection circuits transmitted from the slave controller of each of the uninterruptible power supply apparatuses. The master controller transmits the generated first and second voltage command values to the slave controller of each of the uninterruptible power supply apparatuses. The slave controller generates a first control signal for controlling a converter in accordance with the received first voltage command value. The slave controller generates a second control signal for controlling the inverter in accordance with the received second voltage command value.

Abstract: A power conversion device includes a housing, a power conversion unit, a fan, and a flexible shutter. The shutter is in a sheet shape. The shutter includes an end portion and a movable portion, the end portion being fixed to at least one of the housing and a frame body, the movable portion being movable with respect to the housing. The shutter is configured to be deformed by wind from the fan in a case where the fan is driven and to form a gap through which the wind passes between the shutter and at least one of the housing and the frame body.

Abstract: In an active gas generation apparatus of the present invention, an auxiliary conductive film provided on a first electrode dielectric film is provided to overlap part of an active gas flow path in plan view, and the auxiliary conductive film is set to the ground potential. An active gas auxiliary member provided on a second electrode dielectric film is provided to fill part of the active gas flow path between a discharge space and a gas ejection hole in a dielectric space between the first and second electrode dielectric films in order to limit to an active gas flow gap.