Abstract: A power conversion device that supplies power to a multiphase load based on a first command value includes: a multiphase inverter circuit in which legs including two series-connected semiconductor switching elements are connected in parallel between positive and negative terminals of a DC power supply; a modulation voltage generator that generates a second command value including a fundamental wave component of the first command value and a harmonic component including at least one sine wave having a frequency that is an odd multiple of the fundamental wave component; a carrier signal generator that generates a carrier signal of a triangular wave having a frequency that is an odd multiple of the fundamental wave component; and a gate signal generator that generates a gate signal for driving the semiconductor switching elements in accordance with a result of comparison between the second command value and the carrier signal.

Abstract: The drive system includes a motor, a power converter, and a controller. The motor is a reluctance motor that rotates in response to feeding of electric power. The power converter includes multiple switching elements and is connected directly to the motor. The power converter converts electric power fed from a power source into electric power to be fed to the motor and feeds the converted electric power to the motor. The controller controls the switching elements included in the power converter.

Abstract: A control device includes: a current detector that detects a stator current flowing between a voltage applicator and a stator winding of a rotary machine; a controller that computes a voltage command value based on the stator current and a rotor position, the voltage command value being a command value of a stator voltage applied to the stator winding; a PWM modulator that generates a gate signal such that a value obtained by smoothing the stator voltage matches the voltage command value, and to use this gate signal to control turning on and off of switching elements provided in the voltage applicator; a voltage integrator that computes a voltage integration value by integrating the gate signal; and a position estimator that estimates the rotor position based on the voltage integration value and the stator current.

Abstract: A control device includes a current detector that detects a stator current flowing between a voltage application unit and a stator winding of a rotating machine; a control unit that computes a voltage command value that is a command value for a stator voltage to be applied to the stator winding on the basis of the stator current and a rotor position serving as position information of a rotor of the rotating machine; a PWM modulator that performs on-off control of switching elements of the voltage application unit so that a smoothed value of the stator voltage matches the voltage command value; and a position estimator that estimates, on the basis of the voltage command value and the stator current, the rotor position through a filter that removes a frequency component of a fundamental frequency of rotational speed of the rotating machine.

Abstract: A control device for a rotating machine includes a current detector that detects stator currents flowing through a stator of the rotating machine; a position estimator that computes a rotor position estimate and a rotational speed estimate on the basis of computed flux linkages of the rotating machine, the rotor position estimate being an estimated position of a rotor of the rotating machine, the rotational speed estimate being an estimated speed; a control unit that outputs stator voltage command values based on the stator currents and the rotor position estimate for driving the rotating machine; and a voltage application unit that applies drive voltages to the rotating machine on the basis of the stator voltage command values. The position estimator updates the computed flux linkages on the basis of the stator voltage command values, the rotational speed estimate, and the most recent computed flux linkages.

Abstract: A gradationally controlled voltage inverter, which is a power conversion device, controls a gate impedance of a main inverter before a capacitor voltage VDCS of a sub-inverter is controlled at a predetermined voltage so as to be larger than a gate impedance of the main inverter after the capacitor voltage VDCS of the sub-inverter is controlled at the predetermined voltage. This reduces the noise caused by the main inverter when the capacitor voltage VDCS of the sub-inverter is not controlled at the predetermined voltage.

Abstract: A power conversion device includes a neutral point clamped multilevel power converter and a control device. The control device includes a modulation voltage generator which generates modulation phase voltage commands using phase voltage commands and phase currents, and a PWM modulator which generates gate signals for driving the power converter, using the modulation phase voltage commands. The modulation voltage generator calculates offset voltage so that, for a middle phase in which a high-low rank is middle among the phase voltage commands for respective phases, a polarity of the phase voltage command does not become opposite to a polarity of the phase current, and superimposes the offset voltage as first common voltage on the phase voltage commands for respective phases, to generate the modulation phase voltage commands.

Abstract: A motor control device includes: a power source device including a DC-output power conversion device having a first mode for outputting first voltage and a second mode for outputting second voltage higher than the first voltage; a power supply device; and a control device, and controls a motor. When a flying object takes off, the control device controls the power conversion device in the second mode. When the control device judges that flight information which is one or both of information of a motor parameter obtained along with control for the motor and information of an environmental factor relevant to the flight altitude satisfies a predetermined condition, or when the control device has received an operation mode signal for which the first mode is selected on the basis of the flight information during control for the motor, the control device controls the power conversion device in the first mode.

Abstract: A gradationally controlled voltage inverter, which is a power conversion device, controls a gate impedance of a main inverter before a capacitor voltage VDCS of a sub-inverter is controlled at a predetermined voltage so as to be larger than a gate impedance of the main inverter after the capacitor voltage VDCS of the sub-inverter is controlled at the predetermined voltage. This reduces the noise caused by the main inverter when the capacitor voltage VDCS of the sub-inverter is not controlled at the predetermined voltage.

Abstract: A control device includes: a current detector that detects a stator current flowing between a voltage applicator and a stator winding of a rotary machine; a controller that computes a voltage command value based on the stator current and a rotor position, the voltage command value being a command value of a stator voltage applied to the stator winding; a PWM modulator that generates a gate signal such that a value obtained by smoothing the stator voltage matches the voltage command value, and to use this gate signal to control turning on and off of switching elements provided in the voltage applicator; a voltage integrator that computes a voltage integration value by integrating the gate signal; and a position estimator that estimates the rotor position based on the voltage integration value and the stator current.

Abstract: Provided is a gradationally controlled inverter formed by series-connection between: a main inverter circuitry which has main inverter arms for outputting AC voltages for respective phases, and to which a voltage of a DC source is applied through a DC busbar; and a sub-inverter circuitry having three single-phase sub-inverters. Each of short-circuit switches is connected between an input terminal and an output terminal of a corresponding one of the sub-inverters. At the time of a failure of the sub-inverter, a bypass for current is formed for only the failure phase by causing short-circuiting at the short-circuit switch connected to the sub-inverter, and only the main inverter arm for the failure phase is operated as a three-level inverter.

Abstract: A control device includes a current detector that detects a stator current flowing between a voltage application unit and a stator winding of a rotating machine; a control unit that computes a voltage command value that is a command value for a stator voltage to be applied to the stator winding on the basis of the stator current and a rotor position serving as position information of a rotor of the rotating machine; a PWM modulator that performs on-off control of switching elements of the voltage application unit so that a smoothed value of the stator voltage matches the voltage command value; and a position estimator that estimates, on the basis of the voltage command value and the stator current, the rotor position through a filter that removes a frequency component of a fundamental frequency of rotational speed of the rotating machine.

Abstract: A motor control device includes: a step-down device including a DC-output power conversion device having a first mode for outputting first voltage and a second mode for outputting second voltage lower than the first voltage; a power supply device; and a control device, and controls a motor. When a flying object takes off, the control device controls the power conversion device in the first mode. When the control device judges that flight information which is one or both of information of a motor parameter obtained along with control for the motor and information of an environmental factor relevant to the flight altitude of satisfies a predetermined condition, or when the control device has received an mode signal for which the second mode is selected on the basis of the flight information during control for the motor, the control device controls the power conversion device in the second mode.

Abstract: A power conversion device includes a power conversion controller that generates gate signals for controlling operation of a three-phase three-level inverter and of three single-phase inverters, based on sinusoidal phase voltage commands. In the power conversion controller, the sinusoidal phase voltage commands are divided into three-phase instantaneous voltage commands to be indicated to the three-phase three-level inverter, and mean voltage commands to be indicated to the respective three single-phase inverters. When the sum of the three-phase instantaneous voltage commands is a positive value, a common voltage component is superimposed on each of the three mean voltage commands to make the sum of the three mean voltage commands a non-positive value, and when the sum of the three-phase instantaneous voltage commands is a negative value, the common voltage component is superimposed on each of the three mean voltage commands, making the sum of the three mean voltage commands non-negative.

Abstract: The drive system includes a motor, a power converter, and a controller. The motor is a reluctance motor that rotates in response to feeding of electric power. The power converter includes multiple switching elements and is connected directly to the motor. The power converter converts electric power fed from a power source into electric power to be fed to the motor and feeds the converted electric power to the motor. The controller controls the switching elements included in the power converter.

Abstract: A power converter includes an inverter circuit connected between the positive and negative terminals of a DC power supply, three single-phase bridge circuits each connected in series between an AC terminal of one of different phases of the inverter circuit and a motor, and a power conversion controller that generates gate signals to control operations of the inverter circuit and the three single-phase bridge circuits based on phase voltage commands. When a semiconductor switching element of the single-phase bridge circuits fails, the power conversion controller sets the output voltage of the single-phase bridge circuit of a phase to which the faulty semiconductor switching element belongs to zero to continue operation.

Abstract: A display device comprises a liquid crystal panel including a plurality of pixels and an imaging device arranged on a back side of the liquid crystal panel. The imaging device has an imaging region overlaps with the imaging device and the other region other than the imaging region in a plan view. A plurality of linear electrodes is arranged separately from each other in the imaging region. Among the plurality of linear electrodes, a first pair of linear electrodes are separated by a first interval and a second pair of linear electrodes are separated by a second interval different from the first interval in a plan view. The first pair of linear electrodes and the second pair of linear electrodes are irregularly arranged.

Abstract: A power converter includes an inverter circuit connected to positive and negative terminals of a direct current power supply, three H-bridge circuits, and a power conversion controller. The conversion controller calculates a first three-phase common voltage common to three phases; generates second phase voltage commands obtained by superimposing the calculated first three-phase common voltage on first phase voltage commands; calculates a second three-phase common voltage; generates third phase voltage commands obtained by superimposing the calculated second three-phase common voltage on the second phase voltage commands; and generates gate signals to first legs based on polarity of the third phase voltage commands and generates gate signals to second legs according to the third phase voltage commands.

Abstract: Provided is a gradationally controlled inverter formed by series-connection between: a main inverter circuitry which has main inverter arms for outputting AC voltages for respective phases, and to which a voltage of a DC source is applied through a DC busbar; and a sub-inverter circuitry having three single-phase sub-inverters. Each of short-circuit switches is connected between an input terminal and an output terminal of a corresponding one of the sub-inverters. At the time of a failure of the sub-inverter, a bypass for current is formed for only the failure phase by causing short-circuiting at the short-circuit switch connected to the sub-inverter, and only the main inverter arm for the failure phase is operated as a three-level inverter.

Abstract: A motor control device includes: a power source device including a DC-output power conversion device having a first mode for outputting first voltage and a second mode for outputting second voltage higher than the first voltage; a power supply device; and a control device, and controls a motor. When a flying object takes off, the control device controls the power conversion device in the second mode. When the control device judges that flight information which is one or both of information of a motor parameter obtained along with control for the motor and information of an environmental factor relevant to the flight altitude satisfies a predetermined condition, or when the control device has received an operation mode signal for which the first mode is selected on the basis of the flight information during control for the motor, the control device controls the power conversion device in the first mode.