Abstract: To provide a power conversion device that is effective for improving controllability of power in power conversion for multilevel voltage output. A power conversion device includes a switching circuit configured to supply a current to a motor by connecting and disconnecting a first point having a first potential, a second point having a second potential greater than the first potential, and a neutral point having a neutral potential between the first potential and the second potential to and from the motor, a neutral potential control unit configured to control the switching circuit in a manner to maintain the neutral potential within a target range, and a current control unit configured to increase a supply current to the motor without affecting a driving force generated by the motor at least when controlling the switching circuit 16 by the neutral potential control unit.

Abstract: A power conversion device connected in parallel to a second power conversion device including power conversion circuitry that performs power conversion by changing a connection state between first multiple lines on a primary side and second multiple lines on a secondary side, baseline selection circuitry that selects one of the second multiple lines on the secondary side as a baseline and partial modulation control circuitry that controls the power conversion circuitry to maintain a state in which the baseline is connected to one of the first multiple lines on the primary side and to change a connection state between other second multiple lines on the secondary side and the first multiple lines on the primary side, wherein the baseline selection circuitry switches a line selected as the baseline based on a switching timing used by second baseline selection circuitry of the second power conversion device to select a second baseline.

Abstract: According to one embodiment, a memory system includes a non-volatile memory array with a plurality of memory cells. Each memory cell is a multilevel cell to which multibit data can be written. The non-volatile memory array includes a first storage region in which the multibit data of a first bit level is written and a second storage region in which data of a second bit level less than the first bit level is written. A memory controller is configured to move pieces of data from the first storage region to the second storage region based on the number of data read requests for the pieces of data received over a period of time or on external information received from a host device that sends read requests.

Abstract: A power conversion device includes processing circuitry that estimates a magnet magnetic flux of an electric motor based on a d-axis magnetic flux generated in the electric motor, a d-axis inductance of the electric motor, and a d-axis current flowing in the electric motor, estimates a q-axis inductance of the electric motor based on a q-axis magnetic flux generated in the electric motor and a q-axis current flowing in the electric motor, estimates a drive force of the electric motor based on the magnet magnetic flux and the q-axis inductance, and corrects a current command such that the drive force follows a drive force command.

Abstract: According to one embodiment, a memory system includes a non-volatile memory array with a plurality of memory cells. Each memory cell is a multilevel cell to which multibit data can be written. The non-volatile memory array includes a first storage region in which the multibit data of a first bit level is written and a second storage region in which data of a second bit level less than the first bit level is written. A memory controller is configured to move pieces of data from the first storage region to the second storage region based on the number of data read requests for the pieces of data received over a period of time or on external information received from a host device that sends read requests.

Abstract: A power conversion device includes processing circuitry that estimates a magnet magnetic flux of an electric motor based on a d-axis magnetic flux generated in the electric motor, a d-axis inductance of the electric motor, and a d-axis current flowing in the electric motor, estimates a q-axis inductance of the electric motor based on a q-axis magnetic flux generated in the electric motor and a q-axis current flowing in the electric motor, estimates a drive force of the electric motor based on the magnet magnetic flux and the q-axis inductance, and corrects a current command such that the drive force follows a drive force command.

Abstract: A power conversion device includes a power conversion circuit including a temperature sensor configured to detect a temperature at a sensor position and a switch configured to switch a connection on and off at a switch position separated from the sensor position; a loss calculation processing circuitry configured to calculate a power loss in the switch; a loss correction processing circuitry configured to correct a calculation result of the power loss on the basis of a detection result of the temperature at the sensor position; a temperature correction processing circuitry configured to correct the detection result of the temperature on the basis of the calculation result of the power loss; and a temperature estimation processing circuitry configured to estimate a temperature at the switch position on the basis of a corrected calculation result of the power loss and a corrected detection result of the temperature.

Abstract: A power conversion apparatus connectable in parallel to a second power conversion apparatus includes circuitry that generates a carrier wave, generates a pulse signal synchronized with the carrier wave, generates power that is based on a width of the pulse signal, obtains a monitor value corresponding to a circulating current circulating between the power conversion apparatus and the second power conversion apparatus, and based on the monitor value obtained while the power conversion circuitry is generating driving power, changes a period of the carrier wave to decrease the circulating current.

Abstract: A device includes: a first power conversion circuitry configured to convert primary-side power into secondary-side power; and a control circuitry configured to: generate a command value associated with the secondary-side power; calculate a limited command value by modifying the command value so that the command value is equal to or less than a secondary-side limit, wherein the first power conversion circuitry is controlled based on the limited command value; transmit the limited command value to a second power conversion device comprising a second power conversion circuitry connected in parallel to the first power conversion circuitry; receive, from the second power conversion device, information indicating an adjustment value, wherein the adjustment value is added to the limited command value for controlling the second power conversion circuitry; and modify the secondary-side limit based on a difference between a primary-side limit associated with the primary-side power and the adjustment value.

Abstract: A power conversion device connected in parallel to a second power conversion device including power conversion circuitry that performs power conversion by changing a connection state between first multiple lines on a primary side and second multiple lines on a secondary side, baseline selection circuitry that selects one of the second multiple lines on the secondary side as a baseline and partial modulation control circuitry that controls the power conversion circuitry to maintain a state in which the baseline is connected to one of the first multiple lines on the primary side and to change a connection state between other second multiple lines on the secondary side and the first multiple lines on the primary side, wherein the baseline selection circuitry switches a line selected as the baseline based on a switching timing used by second baseline selection circuitry of the second power conversion device to select a second baseline.

Abstract: A device includes: a first power conversion circuitry configured to convert primary-side power into secondary-side power; and a control circuitry configured to: generate a command value associated with the secondary-side power; calculate a limited command value by modifying the command value so that the command value is equal to or less than a secondary-side limit, wherein the first power conversion circuitry is controlled based on the limited command value; transmit the limited command value to a second power conversion device comprising a second power conversion circuitry connected in parallel to the first power conversion circuitry; receive, from the second power conversion device, information indicating an adjustment value, wherein the adjustment value is added to the limited command value for controlling the second power conversion circuitry; and modify the secondary-side limit based on a difference between a primary-side limit associated with the primary-side power and the adjustment value.

Abstract: A power conversion apparatus connectable in parallel to a second power conversion apparatus includes circuitry that generates a carrier wave, generates a pulse signal synchronized with the carrier wave, generates power that is based on a width of the pulse signal, obtains a monitor value corresponding to a circulating current circulating between the power conversion apparatus and the second power conversion apparatus, and based on the monitor value obtained while the power conversion circuitry is generating driving power, changes a period of the carrier wave to decrease the circulating current.

Abstract: A matrix convertor includes a power convertor and a controller. The power convertor is disposed between a power system and a rotating electric machine, and includes a plurality of bidirectional switches. The controller is configured to control an exciting current flowing from the power convertor to the rotating electric machine so as to control a power factor on a side of the power system.

Abstract: A matrix converter includes a power converter and a controller. The power converter includes bidirectional switches each having a controllable conducting direction. The bidirectional switches are disposed between input terminals and output terminals. The input terminals are respectively coupled to phases of an AC power source. The output terminals are respectively coupled to phases of a load. The controller controls the bidirectional switches. A first commutation controller performs commutation control when the conducting direction is unidirectional. A second commutation controller performs the commutation control when the conducting direction is bidirectional. A selector selects between the first commutation controller and the second commutation controller to perform the commutation control based on a state of an output current from the power converter.

Abstract: A matrix converter includes a selector, a commutation controller, a determinator, and a condition changer. The selector selects one commutation pattern from plurality of commutation patterns based on a state of a phase voltage of a AC power source and a state of a phase current of a load. The commutation controller performs commutation control by controlling bidirectional switches pursuant to the commutation pattern selected by the selector to switch a connection state of the AC power source and the load. The determinator determines a power loss generated by the commutation control in the bidirectional switches. The condition changer changes the commutation patterns which become a selection target of the selector or a selection condition of the commutation patterns which become the selection target of the selector, based on the power loss determined by the determinator.

Abstract: A matrix converter includes a power converter and a commutator. The power converter includes a plurality of bidirectional switches provided between respective phases of an AC power source and respective phases of a load. The commutator is configured to perform commutation control by which input phases connected to output phases are switched using the bidirectional switches. The commutator includes a selector configured to select one commutation pattern from a plurality of commutation patterns based on at least one of a state of phase voltages of the AC power source and a state of phase currents of the load, and a commutation controller configured to perform commutation control by controlling the bidirectional switches pursuant to the commutation pattern selected by the selector to switch a connection state of the AC power source and the load.

Abstract: A matrix convertor includes a power convertor and a controller. The power convertor is disposed between a power system and a rotating electric machine, and includes a plurality of bidirectional switches. The controller is configured to control an exciting current flowing from the power convertor to the rotating electric machine so as to control a power factor on a side of the power system.

Abstract: A matrix converter according to an embodiment includes a voltage command corrector and a drive signal generator. The voltage command corrector corrects the magnitude of an output voltage command on the basis of amplitude variations of an input current from an AC power supply to a power converter, the amplitude variations being caused by a ripple component of the input current. The drive signal generator generates drive signals that turn ON/OFF a plurality of bidirectional switches on the basis of the output voltage command corrected by the voltage command corrector.

Abstract: A power converting apparatus includes: a power converter provided between each phase of an AC power source and each phase of a load; a controller for controlling the power converter to perform a power conversion control between the AC power source and the load; and a filter provided between the AC power source and the power converter. The controller has: an oscillation component detector to detect an oscillation component of an input voltage of the power converter or an oscillation component included in a current flowing through the filter; and an output voltage controller to control an output voltage of the power converter to suppress a resonance of the filter based on the oscillation component.

Abstract: A power converting apparatus includes a power converter, a controller, and a filter. Further, the controller includes a command generator, an estimator, a voltage error calculator, and an output voltage controller. The command generator is configured to generate an output voltage command. The estimator is configured to estimate the output voltage based on an output current of the power converter. The voltage error calculator is configured to calculate a voltage difference between the output voltage command and the estimated output voltage. The output voltage controller is configured to control the output voltage to suppress a resonance of the filter based on the voltage difference.