Abstract: A first winding, a second winding, a fourth winding, and a fifth winding functioning as a transformer are wound around respective side legs of a three-leg core. Third windings functioning as a DC reactor are wound around a center leg. Winding directions of the first winding, the second winding, and the third windings are set so that magnetic fluxes generated by DC currents flowing through the respective windings merge in the same direction at the center leg, and winding directions of the fourth winding and the fifth winding are set so that magnetic fluxes generated by AC currents flowing through the respective windings cancel each other at the center leg. Thus, the transformer and the DC reactor are integrated using the three-leg core, whereby size reduction and loss reduction of the integrated magnetic component are achieved.

Abstract: This power conversion device includes: a rectification circuit; an inverter circuit having a full-bridge configuration, and having a DC capacitor, and first and second legs each of which has two switching elements connected in series to each other; a transformer; and a control circuit for controlling operation of the inverter circuit, wherein the control circuit controls an ON period for the first leg, thereby controlling increase/decrease in current flowing through a first rectification circuit from an AC input, and controls an ON period for the second leg and a phase shift amount between the ON period for the first leg and the ON period for the second leg, thereby controlling voltage of the DC capacitor to be constant. Thus, it becomes possible to achieve high-power-factor control and output power control at the same time by a single stage of full-bridge inverter circuit.

Abstract: This power conversion device includes a rectification circuit, a reactor, an inverter circuit, and an isolation transformer. The inverter circuit is composed of a first leg A, a second leg B, and a DC capacitor connected in parallel between DC buses. A first AC end of the first leg A is connected to a positive DC terminal of the rectification circuit via the reactor. High power factor control of current iac flowing from an AC power supply via the rectification circuit is performed by PWM control for the first leg A, and voltage Vdc of the DC capacitor is controlled by PWM control for the second leg B using a duty cycle equal to or smaller than that for the first leg A, thereby controlling power outputted to the secondary side of the isolation transformer.

Abstract: An electric power conversion device includes a transformer composed of three or more windings magnetically coupled with each other, wherein power supply sources, are connected to at least two windings, via switching circuits, a load is connected to at least one winding, and a control circuit temporally divides, within one switching period, a total ON time during which power is supplied, in accordance with the number of the power supply sources, to supply power, the one switching period being the minimum repetitive unit during which power is supplied alternately. The control circuit allocates the divided ON times to the respective switching circuits, and the switching circuits, supply power from the power supply sources, to the load side during the allocated ON times, respectively.

Abstract: A main circuit of a power conversion device includes: an AC/DC converter for performing power factor correction control for a single-phase AC power supply; and a DC/DC converter connected to the AC/DC converter via a DC capacitor. In order to reduce ripple voltage and ripple current for the DC capacitor, a control circuit superimposes, onto a DC current command, an AC current command having the minimum value at the zero cross phase of the single-phase AC power supply and having the maximum value at the peak phase thereof, to generate an output current command for the DC/DC converter, and performs output control for the DC/DC converter, using the output current command.

Abstract: A power conversion device that distributes input power to multiple outputs in accordance with power requirement of a load, using a plurality of magnetically coupled windings. In the case of supplying power from an AC power supply, at least one of an AC/DC converter and first to fourth switching circuits controls voltage on an output side of the AC/DC converter, based on a deviation between a detected value and a target value of the voltage. In the case of supplying power from a first DC voltage source or a second DC voltage source, the second switching circuit or the fourth switching circuit provided between the first DC voltage source or the second DC voltage source and the transformer supplies power based on an arbitrary time ratio.

Abstract: The power reception amount of input power from an AC power supply is controlled through a first switching circuit. DC voltage is controlled through a second switching circuit, to control charge power for a first DC voltage source. DC voltage obtained by a third switching circuit is converted to AC by an inverter, to supply the resultant power to an AC load. DC voltage is controlled through a fourth switching circuit, to control charge power for a second DC voltage source. Thus, distribution control of the input power is performed. In addition, in the distribution control of the input power, operation of the second switching circuit or the fourth switching circuit is stopped to allow stop of the charging for the first DC voltage source or the second DC voltage source.

Abstract: A main circuit of a power conversion device includes: an AC/DC converter for performing power factor correction control for a single-phase AC power supply; and a DC/DC converter connected to the AC/DC converter via a DC capacitor. In order to reduce ripple voltage and ripple current for the DC capacitor, a control circuit superimposes, onto a DC current command, an AC current command having the minimum value at the zero cross phase of the single-phase AC power supply and having the maximum value at the peak phase thereof, to generate an output current command for the DC/DC converter, and performs output control for the DC/DC converter, using the output current command.

Abstract: An electric power conversion device includes a transformer composed of three or more windings magnetically coupled with each other, wherein power supply sources, are connected to at least two windings, via switching circuits, a load is connected to at least one winding, and a control circuit temporally divides, within one switching period, a total ON time during which power is supplied, in accordance with the number of the power supply sources, to supply power, the one switching period being the minimum repetitive unit during which power is supplied alternately. The control circuit allocates the divided ON times to the respective switching circuits, and the switching circuits, supply power from the power supply sources, to the load side during the allocated ON times, respectively.

Abstract: This power conversion device includes a rectification circuit, a reactor, an inverter circuit, and an isolation transformer. The inverter circuit is composed of a first leg A, a second leg B, and a DC capacitor connected in parallel between DC buses. A first AC end of the first leg A is connected to a positive DC terminal of the rectification circuit via the reactor. High power factor control of current iac flowing from an AC power supply via the rectification circuit is performed by PWM control for the first leg A, and voltage Vdc of the DC capacitor is controlled by PWM control for the second leg B using a duty cycle equal to or smaller than that for the first leg A, thereby controlling power outputted to the secondary side of the isolation transformer.

Abstract: A power conversion device includes a half bridge type inverter circuit that includes semiconductor elements, and a DC capacitor and that is connected to a positive side bus of the AC power supply, a smoothing capacitor, a semiconductor element that is connected between the semiconductor element and a positive side of the smoothing capacitor, and a semiconductor element that is connected between the semiconductor element and a negative side of the smoothing capacitor, in which turning-on and turning-off of the semiconductor element are controlled so that a DC voltage of the DC capacitor tracks a target voltage, and turning-on and turning-off of the semiconductor elements are controlled so that a DC voltage of the smoothing capacitor tracks a target voltage and thus an input power factor from the AC power supply is adjusted.

Abstract: A three-phase power conversion device includes: single-phase inverters having AC output ends connected in series to the respective phases of the three-phase AC lines; a control device for performing PWM control for each single-phase inverter based on a voltage command V*; and an AC voltage detection circuit for detecting a phase and a voltage amplitude of three-phase AC voltage. The control device adds a zero-phase component Vo common to the three phases to a basic command Vx* for each phase to generate a voltage command V*. The zero-phase component Vo is generated by applying an amplitude a calculated based on the phase and the voltage amplitude to reference zero-phase voltage Voo that has been set, thereby reducing a peak of the voltage command V* for each single-phase inverter.

Abstract: A transformer is composed of three or more windings magnetically coupled. An AC/DC converter (2) for converting AC power of an AC power supply (1), a capacitor (3), and a switching circuit (4) are connected to one winding (6a), and a switching circuit (8) or (30) for power conversion of a DC power supply is connected to at least one of the other windings. Voltage of the capacitor (3) or the AC power supply (1) is detected. On the basis of the detected value thereof, the operation state of each switching circuit (4), (8), (30) is determined by an operation state determination circuit (101). On the basis of a result of the determination, the power supply is switched among the AC power supply (1) and the DC power supplies (11) and (34) by an output switch circuit (103).

Abstract: A DC-DC converter wherein a series reactor and primary-side terminals of a transformer are connected between output terminals of a full-bridge inverter in which each of an upper arm and a lower arm includes a switching element and a freewheel diode, and a rectifier circuit and a filter circuit are connected to secondary-side terminals of the transformer. The DC-DC converter includes a circulation current generation mode in which a circulation current flowing between the transformer and the switching element is generated in a power non-transmission period, and a circulation current interruption mode in which the circulation current is interrupted.

Abstract: The power reception amount of input power from an AC power supply is controlled through a first switching circuit. DC voltage is controlled through a second switching circuit, to control charge power for a first DC voltage source. DC voltage obtained by a third switching circuit is converted to AC by an inverter, to supply the resultant power to an AC load. DC voltage is controlled through a fourth switching circuit, to control charge power for a second DC voltage source. Thus, distribution control of the input power is performed. In addition, in the distribution control of the input power, operation of the second switching circuit or the fourth switching circuit is stopped to allow stop of the charging for the first DC voltage source or the second DC voltage source.

Abstract: A power conversion device that distributes input power to multiple outputs in accordance with power requirement of a load, using a plurality of magnetically coupled windings. In the case of supplying power from an AC power supply, at least one of an AC/DC converter and first to fourth switching circuits controls voltage on an output side of the AC/DC converter, based on a deviation between a detected value and a target value of the voltage. In the case of supplying power from a first DC voltage source or a second DC voltage source, the second switching circuit or the fourth switching circuit provided between the first DC voltage source or the second DC voltage source and the transformer supplies power based on an arbitrary time ratio.

Abstract: An electric power conversion device which performs conversion to desired voltage using charge and discharge of a DC capacitor includes: a reactor connected to a rectification circuit; a leg part in which diodes and first and second switching elements are connected in series between positive and negative terminals of a smoothing capacitor, and to which the reactor is connected; and the DC capacitor. A control circuit performs high-frequency PWM control for the first and second switching elements using the same drive cycle, with their reference phases shifted from each other by a half cycle, and controls a sum and a ratio of ON periods of the first and second switching elements in one cycle, thereby allowing both high-power-factor control for input AC current and voltage control for the DC capacitor.

Abstract: A DC-DC converter wherein a series reactor and primary-side terminals of a transformer are connected between output terminals of a full-bridge inverter in which each of an upper arm and a lower arm includes a switching element and a freewheel diode, and a rectifier circuit and a filter circuit are connected to secondary-side terminals of the transformer. The DC-DC converter includes a circulation current generation mode in which a circulation current flowing between the transformer and the switching element is generated in a power non-transmission period, and a circulation current interruption mode in which the circulation current is interrupted.

Abstract: A three-phase power conversion device includes: single-phase inverters having AC output ends connected in series to the respective phases of the three-phase AC lines; a control device for performing PWM control for each single-phase inverter based on a voltage command V*; and an AC voltage detection circuit for detecting a phase and a voltage amplitude of three-phase AC voltage. The control device adds a zero-phase component Vo common to the three phases to a basic command Vx* for each phase to generate a voltage command V*. The zero-phase component Vo is generated by applying an amplitude a calculated based on the phase and the voltage amplitude to reference zero-phase voltage Voo that has been set, thereby reducing a peak of the voltage command V* for each single-phase inverter.

Abstract: A power conversion device includes a half bridge type inverter circuit that includes semiconductor elements, and a DC capacitor and that is connected to a positive side bus of the AC power supply, a smoothing capacitor, a semiconductor element that is connected between the semiconductor element and a positive side of the smoothing capacitor, and a semiconductor element that is connected between the semiconductor element and a negative side of the smoothing capacitor, in which turning-on and turning-off of the semiconductor element are controlled so that a DC voltage of the DC capacitor tracks a target voltage, and turning-on and turning-off of the semiconductor elements are controlled so that a DC voltage of the smoothing capacitor tracks a target voltage and thus an input power factor from the AC power supply is adjusted.