Abstract: An electrolytic cell power supply device is provided, the electrolytic cell power supply device includes: a first converter configured to convert alternating current power supplied from a power system into direct current power; a storage element configured to store direct current power output from the first converter; a second converter configured to convert the direct current power stored in the storage element into other direct current power corresponding to the electrolytic cell, and supply the direct current power after the conversion between the anode and the cathode of the electrolytic cell; and a control device configured to control operations of the first and second converters, the control device includes a corrosion prevention operation mode In a power interruption of the power system, the corrosion prevention operation mode controlling the operation of the second converter to suppress a generation of a reverse current by supplying, to the electrolytic cell, a direct current power.

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 disclosure, in a high-voltage side electrode component, the electrode main dielectric film is provided on the lower surface of the electrode conductive film, and the electrode additional dielectric film is disposed below the electrode main dielectric film at an upper main/additional inter-dielectric distance. The electrode main dielectric film includes the whole electrode conductive film in a plan view, and has a formation area larger than the electrode conductive film. The electrode additional dielectric film includes the electrode conductive film in a plan view and has a formation area slightly larger than the electrode conductive film and smaller than the electrode main dielectric film. The ground side electrode component has the same features as the above-mentioned features of the high-voltage side electrode component.

Abstract: A drive system (1) drives a multi-phase AC motor (2) having a plurality of windings. The drive system (1) includes a first power converter (3U), a second power converter (3V), a first conversion controller (20U), and a second conversion controller (20V). The first power converter (3U) causes a current to flow through a winding of a first phase of the multi-phase AC motor (2). The second power converter (3V) causes a current to flow through a winding of a second phase of the multi-phase AC motor (2). The first conversion controller (20U) decides on either a three-level phase voltage waveform or a five-level phase voltage waveform on the basis of setting information for designating a type of phase voltage waveform and controls the first power converter (3U) so that the decided phase voltage waveform is output from the first power converter (3U).

Abstract: A power supply device according to an embodiment is configured to supply DC power to an electrolytic cell producing hydrogen by electrolysis. The power supply device includes a power converter, a reactor, and a filter circuit; the power converter is self-commutated and includes a first output terminal and a second output terminal; the second output terminal is configured to output a positive voltage with respect to the first output terminal; the reactor is connected in series to at least one of the first output terminal or the second output terminal; and the filter circuit is connected between an anode and a cathode of the electrolytic cell. The filter circuit is a low-pass filter. A cutoff frequency of the filter circuit is set to be less than a switching frequency of the power converter.

Abstract: A power conversion device includes a major circuit part converting a power of a distributed power source into AC power corresponding to a power system, and a controller controlling an operation of the major circuit part; the controller includes an estimated value calculation part and a reactive power calculation part; the estimated value calculation part calculates an estimated value of a resistance component of a system impedance of the power system, an estimated value of a reactance component of the system impedance, and an estimated value of a voltage value of the infinite bus power system based on an active power value of a connection point to the power system, a reactive power value of the connection point, and a voltage value of the connection point.

Abstract: A semiconductor switch drive device (3) includes a drive unit (10), a power supply unit (20), a switch (39), and a control unit (50). The drive unit (10) supplies a control signal to a semiconductor switch (Q) of a main circuit (2) and drives the semiconductor switch (Q). The power supply unit (20) supplies electric power to the drive unit (10). The switch (39) cuts off supply of electric power to the power supply unit (20) by detecting or controlling an overvoltage state on a primary side of the power supply unit (20). The control unit (50) switches a conductive state of the switch (39) on the basis of a voltage of a control terminal of the semiconductor switch (Q).

Abstract: An electric motor drive device that includes an electric motor, a main circuit, a current sensor, and a control unit. The electric motor has a plurality of windings. The main circuit transforms power into AC power and supplies the AC power to each of the plurality of windings. The current sensor detects a load current flowing through each of the windings. The control unit controls the main circuit on the basis of a current value detected by the current sensor and controls an amount of power to be supplied from the main circuit to the electric motor on the basis of an amplitude of the load current associated with detection of an undervoltage state of the AC power supply in a state in which the main circuit uses conversion rule in which an index value for the amplitude of the load current flowing through the plurality of windings is defined.

Abstract: A substrate unit of an embodiment includes a plurality of substrates and a holding part. The plurality of substrates are arranged at a constant interval in a thickness direction. The holding part integrally holds the plurality of substrates and allows, relative to one substrate of the plurality of substrates, another substrate to be movable along a plane direction of the substrate.

Abstract: A control device is a control device of a power conversion device, and includes a conversion value calculation unit that acquires a current value of a current flowing in an alternating-current capacitor connected to a capacitor circuit in an output circuit on an alternating-current side of an inverter circuit and performs conversion of the current value to obtain a predetermined conversion value, and a failure detection unit that compares the conversion value obtained by the conversion value calculation unit and a predetermined determination value to be used in failure detection to detect a failure of the alternating-current capacitor.

Abstract: An uninterruptible power supply device that includes a housing having a rectangular parallelepiped shape, a plurality of power conversion units, and a bus unit for connecting the plurality of power conversion units in parallel to each other. The plurality of power conversion units are stacked in a vertical direction and housed in the housing. The bus unit is arranged in the housing to face a rear surface of the housing. The bus unit includes a plurality of buses extending in the vertical direction, at least one support member that supports the plurality of buses such that the plurality of buses are spaced apart from each other in a horizontal direction, and at least one fixing member that removably fixes each support member to the housing.

Abstract: According to an embodiment, a power conversion system includes a plurality of converters and a control unit. The plurality of converters are provided in parallel for each phase of a multi-phase alternating current power system. The control unit uses a plurality of carrier signals having a prescribed phase difference from each other in carrier comparison type pulse width modulation (PWM) control. The control unit detects a current of a primary side of the plurality of converters at each of four or more even-numbered timings when the four or more even-numbered timings are defined at prescribed time intervals during one cycle of a specific carrier signal among the plurality of carrier signals. The control unit generates a reference voltage for the PWM control using a value of the detected current of the primary side and a value of a reference current of the primary side and updates the reference voltage at each of the four or more even-numbered timings.

Abstract: An EV charging apparatus includes: a plurality of charging stations respectively connected detachably with EVs, the plurality of charging stations being configured to charge power storage devices mounted in the EVs when connected; a plurality of power supply circuits configured to convert power supplied from a power system side into direct current power compatible with the EVs, and to supply the direct current power after the conversion respectively to the plurality of charging stations; a charging/discharging station connected detachably with the EV, the charging/discharging station being configured to charge and discharge the power storage device mounted in the EV when connected; and a bidirectional converter configured to perform power conversion in two directions, the two directions being a direction of charging the power storage device of the EV connected to the charging/discharging station, and a direction of discharging the power storage device of the EV connected to the charging/discharging station.

Abstract: A DC power converter includes a chopper circuit. In a step-up mode, in the chopper circuit, a current path that starts from the DC power supply and returns to the DC power supply through the first reactor, the first connection point, the second switch, the third connection point, the second capacitor, and the fourth connection point in order is formed when the first switch is off and the second switch is on, and a current path that starts from DC power supply and returns to the DC power supply through the first reactor, the first connection point, the first diode, the second connection point, the first capacitor, the third connection point, the second capacitor, and the fourth connection point in order is formed when the first switch is off and the second switch is off.

Abstract: A bidirectional chopper selectively performs: a charging operation to store DC power received from a DC bus in a power storage device; and a discharging operation to output DC power of the power storage device to the DC bus. An inverter converts the DC power received from the DC bus into AC power and supplies the AC power to a load, and converts regenerative power generated by the load into DC power and outputs the DC power to the DC bus. An SOC reference value is set for the power storage device, the SOC reference value being smaller than an upper limit value of a usable range of the SOC and larger than a lower limit value of the usable range. When an AC power supply is sound, a control device controls the bidirectional chopper such that the SOC of the power storage device reaches the SOC reference value.

Abstract: Provided is a surface treatment device capable of performing surface treatment on a treatment surface of a substrate at low cost by reusing a mist of a treatment liquid introduced into a treatment chamber. The surface treatment device is a device for surface treatment of a substrate by causing a treatment liquid to adhere to the treatment surface of the substrate. The surface treatment device includes a mist generator that generates a mist of the treatment liquid; a treatment chamber that introduces the mist generated by the mist generator and causes the introduced mist to adhere to the treatment surface of the substrate; and a circulation path that circulates the mist discharged from the treatment chamber to the treatment chamber together with the mist generated by the mist generator.

Abstract: A control device for a power conversion device includes a voltage recognizing unit configured to detect a voltage at a linkage point of the plurality of power converters, and a control unit configured to control an amplitude and a frequency of a voltage to be output by a power converter to be controlled on the basis of active power and reactive power output by the power converter to be controlled in a case that the power converter to be controlled is caused to perform autonomous operation as a voltage source, and controls active power and reactive power to be output by the power converter to be controlled so as to compensate for excess or deficiency of active power and reactive power at the linkage point on a basis of an amplitude and a frequency of the voltage detected by the voltage recognizing unit.

Abstract: A controller of this uninterruptible power supply apparatus performs, while an inverter power feeding mode is being performed, a test mode in which a bypass circuit is brought into conduction and an output current from an inverter is decreased, and it is determined whether or not the bypass circuit operates normally based on an output voltage from the inverter. Therefore, when the bypass circuit does not operate normally, the bypass circuit can be repaired or replaced, to prevent operation of a load from being stopped when a fault occurs in the inverter.

Abstract: When a general-purpose operation part (22, 23) is hidden by a window part (24), it becomes hard for an operator to visually check an association state between a field device (10A, 10B) and a hardware switch (3). If such a display state has occurred, an HMI server (5) stops a health check signal which is being output to a PLC (6). The PLC (6) detects the stop of the health check signal and forcibly cancels the association state between the field device (10A, 10B) and the hardware switch (3). Thus, a human error can be prevented.

Abstract: An uninterruptible power supply system that includes a selection unit that selects, of a plurality of uninterruptible power supply devices, a necessary number of uninterruptible power supply devices to supply power to a load. Each of the uninterruptible power supply devices performs, when this device is selected, an operating action of supplying power to the load, when this device is not selected, a standby action of not supplying power to the load, and during the standby action, a diagnostic action of diagnosing whether or not a predetermined part of this device has a failure. The selection unit changes uninterruptible power supply devices to be selected, such that the plurality of uninterruptible power supply devices have an equal operating time.