Abstract: A drive system according to an aspect of the embodiment includes a first phase estimation unit, a second phase estimation unit, a state determination unit, and a drive control unit. The first phase estimation unit generates a first phase obtained by estimating a phase of a rotor on the basis of an initial phase at a startup stage of the synchronous motor. The second phase estimation unit generates a second phase obtained by estimating the phase of the rotating rotor on the basis of the operation state of the synchronous motor. The state determination unit determines the operation state of the synchronous motor. The drive control unit controls the driving of the synchronous motor by using any one of the first phase and the second phase according to the determination result of the operation state of the synchronous motor.

Abstract: In the present uninterruptible power supply apparatus, in a switching period in which a bypass power feed mode is switched to an inverter power feed mode, a semiconductor switch is turned on, a first electromagnetic contactor is turned off, a second electromagnetic contactor is turned on and, in this state, an inverter is activated to start a lap power feed mode, and the semiconductor switch is turned off to end the lap power feed mode. Accordingly, the lap power feed mode can be completed in a short time to reduce an increase of a terminal-to-terminal voltage of a capacitor and thereby prevent the terminal-to-terminal voltage of the capacitor from exceeding an upper limit voltage.

Abstract: A drive equipment includes a transformer, a power converter, and a control system. The transformer is configured with a primary winding and a secondary winding, and a winding of an electric motor is connected to the secondary winding. The power converter causes a current to flow through the primary winding of the transformer. The control system performs constant current control on the power converter during a period of a first stage after startup of the electric motor is instructed, to reduce a variation in a current flowing through the primary winding of the transformer, and controls the power converter through variable voltage variable frequency control of the electric motor in a second stage after the first stage.

Abstract: A system frequency detector includes an orthogonal coordinate signal generator generating an orthogonal two-phase voltage signal from a three-phase voltage signal of three-phase alternating current power of a power system by converting the three-phase voltage signal into a two-phase voltage signal orthogonal to the three-phase voltage signal, converting the two-phase voltage signal into a voltage signal of a rotating coordinate system, calculating a moving average of the voltage signal of the rotating coordinate system, and performing an inverse transformation of the voltage signal of the rotating coordinate system after calculating the moving average; and a frequency calculator including an angular frequency calculator calculating an angular frequency of the power system based on the two-phase voltage signal, and an arithmetic unit calculating a system frequency of the power system from the angular frequency, the frequency calculator further including a low-pass filter provided in series with the arithmetic

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 converter including a diode converter, an inverter, a smoothing capacitor, a resistor; a current sensor; an estimation unit; and a control unit. The diode converter rectifies an alternating current from a power supply. The inverter is formed such that a DC side is connected to a DC output of the diode converter and an AC side is connected to an electric motor and includes a semiconductor switching element which converts DC power on the DC side into AC power and a reverse connection diode which is connected in antiparallel with the semiconductor switching element. The smoothing capacitor is provided in the DC output of the diode converter. The resistor is connected in parallel with the smoothing capacitor. The current sensor detects a load current flowing between the inverter and the electric motor.

Abstract: A power conversion device includes a first control device to an m-th control device that are capable of communicating with each other. A k-th control device transmits specific information to control devices other than the k-th control device among the first control device to the m-th control device. The specific information includes voltage values of a plurality of unit converters included in a k-th cell set in each of a first arm to a third arm. From each control device other than the k-th control device among the first control device to the m-th control device, the k-th control device receives specific information including the voltage values of the plurality of unit converters. The k-th control device calculates a phase representative value of the voltage values of the plurality of unit converters included in each of the first arm to the third arm.

Abstract: In a mist flow rate measuring apparatus of the present disclosure, in a transparent pipe, a camera executes imaging processing of reflected light, the imaging processing having at least a part of a mist flowing region through which a mist-containing gas flows set as an imaging target region, and acquires imaging information. A mist flow rate calculation unit executes mist flow rate calculation processing based on the imaging information. The mist flow rate calculation processing includes sum value calculation processing of obtaining a luminance sum value, which is a sum of a plurality of luminance values indicated by the imaging information, and flow rate derivation processing of deriving the flow rate of the raw material mist from the luminance sum value.

Abstract: A drive system of an embodiment includes an initial phase command generation unit, a rotor phase detection unit, and a drive control unit. The initial phase command generation unit generates a phase command value corresponding to an initial phase of a rotor before startup of a synchronous motor. The rotor phase detection unit detects a phase of the rotor and outputs the phase. The drive control unit controls the driving of the synchronous motor by using the phase command value. The initial phase command generation unit adjusts the phase command value to approach the phase of the rotor of a detection result by using the detection result of the phase of the rotor detected before the startup by the rotor phase detection unit.

Abstract: A control system of a power converter includes a plurality of carrier wave generating units which are respectively provided for a plurality of power converters connected between a plurality of DC power supplies and a common AC power supply and which are configured to respectively generate carrier waves on the basis of an AC voltage of the AC power supply. The control system of the power converter can thereby synchronize carrier phases of a plurality of power converters.

Abstract: A power conversion device includes: a power conversion circuit connected to a direct-current power supply and a power system and configured to perform conversion between direct-current power and alternating-current power; a phase-locked loop circuit configured to output a phase instruction value based on a system alternating-current voltage phase of the power system; and a control circuit configured to control the power conversion circuit based on the phase instruction value from the phase-locked loop circuit. The phase-locked loop circuit includes: a phase difference calculation section configured to calculate a phase difference in a predetermined cycle, the phase difference representing a deviation of the phase instruction value from the system alternating-current voltage phase of the power system; a phase difference correction section; and a phase instruction value generation section configured to output the phase instruction value based on an output of the phase difference correction section.

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.

Abstract: A washer includes a conductive main body, a first seal portion, and a second seal portion. The main body includes an annular plate-shaped body and a protruding portion. The protruding portion protrudes in the thickness direction from the outer peripheral portion of the plate-shaped body. The first seal portion covers the inner peripheral surface at the inner peripheral portion and both surfaces in the thickness direction of the plate-shaped body. The second seal portion covers at least the distal end portion of the protruding portion.

Abstract: A system frequency detector includes an orthogonal coordinate signal generator generating an orthogonal two-phase voltage signal from a three-phase voltage signal of three-phase alternating current power by converting the three-phase voltage signal into a two-phase voltage signal orthogonal to the three-phase voltage signal, converting the two-phase voltage signal into a voltage signal of a rotating coordinate system, calculating a moving average of the voltage signal of the rotating coordinate system, and performing an inverse transformation of the voltage signal of the rotating coordinate system after calculating the moving average. A frequency calculator calculates an angular frequency based on the two-phase voltage signal, and an arithmetic unit calculates a system frequency of the power system from the angular frequency.

Abstract: In an uninterruptible power supply apparatus, AC current, which includes a feedback component having a value corresponding to deviation between terminal-to-terminal voltage of a capacitor and reference voltage, and a feed forward component obtained by multiplying load current by a gain, is passed into a converter such that the terminal-to-terminal voltage of the capacitor becomes the reference voltage. The gain is set to a first gain in an inverter power feed mode and a bypass power feed mode, and the gain is set to a second gain smaller than the first gain in a switching period of switching between the inverter power feed mode and the bypass power feed mode, to prevent the terminal-to-terminal voltage of the capacitor from exceeding an upper limit voltage in a lap power feed mode.

Abstract: A coupling member includes: first, second, and third portions each having a flat plate-like shape; and a fillet portion. The first portion has a first side and a second side orthogonal to each other. The second portion is bent at the first side relative to the first portion, and extends to an inner surface of the first portion. The third portion is bent at the second side relative to the first portion, and extends to an inner surface of the first portion. A bend radius of an outer surface of the coupling member at the first side is equal to a bend radius of a surface of a first extending member facing the first side. A bend radius of an outer surface of the coupling member at the second side is equal to a bend radius of a surface of a second extending member facing the second side.

Abstract: In a mist flow rate measuring apparatus of the present disclosure, an external discharge pipe is constituted of a combination of an upstream pipe, a large-diameter transparent pipe, and a downstream pipe. A part of a mist flowing region in the large-diameter transparent pipe is an imaging target region of a mist imaging camera. An inner diameter D31 of the large-diameter transparent pipe is set to a value larger than an inner diameter D7 of the upstream pipe and an inner diameter D8 of the downstream pipe. That is, the large-diameter transparent pipe, the upstream pipe, and the downstream pipe have a magnitude relationship with respect to the inner diameter of {D31>D7=D8}.

Abstract: An overtemperature detecting system according to an embodiment detects a temperature abnormality of a dry-type transformer (hereinafter, referred to as a transformer) cooled by a cooling device. The overtemperature detecting system includes a temperature determining unit. The temperature determining unit determines and outputs a temperature abnormality of the transformer by changing determination conditions of the temperature abnormality of the transformer using operation states during operating and during stopping of the cooling device.

Abstract: A power conversion device includes: a dead time application unit which applies a dead time to only one of a pair of pulse signals; a current polarity detection unit which detects a polarity of an output current; and a gate signal selection unit which, if the polarity of the output current is positive, selects the one pulse signal, to which the dead time has been applied, as a gate signal for a positive arm and selects the other pulse signal as a gate signal for a negative arm, and, if the polarity of the output current is negative, selects the one pulse signal, to which the dead time has been applied, as the gate signal for the negative arm and selects the other pulse signal as the gate signal for the positive arm.

Abstract: The present disclosure relates to a tail end buckling suppression device for a tandem rolling mill rolling a material to be rolled by N (N?2) successive rolling stands. Each i-th rolling stand (1?i?N) of the tandem rolling mill includes an i-th roll bender device screwing down the material to be rolled with preset roll bender pressure. During a period after a tail end of the material to be rolled comes out of one designated j-th rolling stand (1?j?N?1) until the tail end of the material to be rolled comes out of the N-th rolling stand, the tail end buckling suppression device causes each of j+1-th to N-th roll bender devices downstream of the j-th rolling stand to continuously lower the roll bender pressure.